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Abstract Bioleaching technology is being developed as a cost-beneficial and environmentally friendly strategy for the removal of metal ions from sewage sludge. Therefore, this study aims to evaluate the feasibility of bioleaching process for the removal of heavy metals (Pb, Al, Zn, and Cu) from sewage sludge using indigenous iron-oxidizing microorganisms. For this purpose, 10 mL of a sludge-enriched inoculum of iron-oxidizing bacteria with 2 g FeSO4.7H2O was added to a 250-mL Erlenmeyer flask containing 100 mL of the sludge mixture from the secondary and primary sedimentation unit (34.78 g L−1 solids). The samples were stirred in a shaking incubator at 28 °C and 120 rpm for 15 days and analyzed for pH, oxidation–reduction potential (ORP), Fe3+ and heavy metal concentration. In parallel, control samples were performed with 100 mL of sludge sample without the addition of the sludge-enriched inoculum and energy source. It was observed that the concentration of heavy metals decreased continuously over the period of 15 days and the removal efficiency reached 62.7%, 80.7%, 43%, and 75.5% for Al, Cu, Pb, and Zn, respectively. On the other hand, the changes in selective heavy metal removal in the control experiments are very negligible. The results also showed that the specific filtration resistance (SRF) of the sludge decreased by 66.87%. In addition, the results of the SEM, EDX − mapping and XRD analyses before and after the bioleaching experiments confirm the activities of the microorganisms. The results clearly showed that the bioleaching process is an effective approach for removing heavy metals from sewage sludge as well as improving sludge dewatering and reducing the subsequent costs for the dewatered sludge disposal.

Nowadays, health and environmental problems caused by elevated arsenic concentration in water sources have become a major concern for researchers and environmental experts. Therefore, it is necessary to study processes that significantly reduce the arsenic content in aqueous solutions, which is of great interest to environmental experts. This work aimed to evaluate the effect of the pre-oxidation/coagulation process with commercially available coagulants (FeCl3, Al2 (SO4)3·18H2O, and PACl) on the efficiency of arsenic removal (with initial concentration of 73 ± 2.5 μg/L) from Talvar Dam entering the Sheikhi Jan Hamadan water treatment plant. This was demonstrated on a laboratory and operational scale at the water treatment plant under different scenarios (pre-oxidant agents, type of coagulant, solution pH, and different coagulant dosages). It should be noted that, as part of an emergency project, the possibility of arsenic removal at the Sheikhi Jan water treatment plant, which receives Talvar Dam water at a flow rate of 1800 L/s, was investigated. The priority of the researchers and city officials in the present study was to use the potential of the water treatment plant and the existing equipment so that they could remove arsenic quickly and without additional costs. This study was conducted in three stages: laboratory scale, implementation of the process in the water treatment plant, and monitoring of the treatment plant's performance, which continues to this day. The results of this project showed that the pre-oxidation/coagulation process can effectively reduce the concentration of arsenic at the inlet of the treatment plant from to less than national and international recommended values.

This study aimed to assess nano-pumice (NP) from pumice mining waste as a local, cost-effective anode catalyst in microbial fuel cells (MFCs) for treating edible vegetable oil refinery wastewater (EVORW) and generating bioenergy. Pumice mining waste was converted into nano in three stages: crushing up to ≤3 cm, reducing the size of the previous step particles to 150 μm and converting the previous step particles to

In the current work, the behavior of a fixed bed column (FBC) containing an innovative nanocomposite, Fe3O4-ZIF8@eggshell membrane matrix (F-ZIF8@EMM), was investigated in the concurrent elimination of arsenic and nitrate, as two potentially harmful elements (PHEs) in drinking water. Flow rate (6–10 mL/min), column height (10–20 cm), reaction time (30–180 min), pH (5−10), primary content of arsenic (25–100 µg/L), primary content of nitrate (100–200 mg/L), and nanocomposite dose (0.25–1 mg/L) were examined as different operational effects on the simultaneous uptake of arsenic and nitrate from actual water via the as-fabricated novel nanocomposite through various experiments. Characteristics of F-ZIF8@EMM were analyzed via X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), and Brunauer-Emmett-Teller (BET) analyses. The consequences illustrated that the optimal parameters were: flow rate (6 mL/min), primary content of arsenic (100 µg/L), primary content of nitrate (150 mg/L), bed height (20 cm), and pH (7). The simultaneous elimination efficiency of nitrate and arsenic was 90 % under optimal conditions. The FBC fed with water containing arsenic and high nitrate could operate for 440 min with a qm of 226 mg/g. After fitting, different models were identified, with the concurrent uptake of nitrate and arsenic was the optimum fit with the Thomas model (R2 = 0.9998). Analysis of the cost of the process displayed that it should be estimated to be approximately 0.005$ per liter of safe drinking water. This study demonstrates the stability and high efficiency of the newly structured adsorbent after 10 consecutive adsorption cycles. It also validates the significant capacity of the as-made composite F-ZIF8@EMM in the concurrent uptake of nitrate and arsenic. Consequently, the application of FBC technology has shown promise in enhancing this process.

Petrochemical industries can potentially be sources of microplastics. This is the first report that studies the abundance and characteristics of microplastics in different parts of a petrochemical site, and process of changes in microplastics from the place of production to reaching open waters. Samples were taken from 10 points. In order to identify the microplastics, NaCl and ZnCl2 solutions were used for extraction and then H2O2 was used for cleaning and with using different filters, two groups of size were divided. Then, using a stereomicroscope and ATR-FTIR their abundance, color and shape and the type of polymers were determined. The number of microplastics in the soil samples varied from 1483 ± 475 items/Kgdws to 4620 ± 983 items/kgdws, the industrial WWTP sludge, the number of microplastics detected varied from 1233 ± 225 items/L to 1433 ± 372 items/L and in WWTP effluent was determined to be 276 ± 76 items/10 L. on average, 66.38 % and 33.62 % of the detected microplastic particles were in the size range of 0.45μ-20μ and 20μ-2mm, respectively. Also on average, 75.89 % and 24.11 % of the particles were in the density range of 1.2–2 g/cm3 and less than 1.2 g/cm3, respectively. On average, 68.33 %, 14.35 %, 10.55 %, and 6.77 % of the microplastics were in the form of fiber, film, pellet and other, respectively. On average, 29.84 %, 56.27 %, 1.02 %, 2.88 %, 0.97 %, and 8.99 % of the microplastics were black, white, red, blue, green and other respectively. 61 %, 23 %, 8 %, 4 % and 4 % of the investigated particles were classified as PES, PET, PE, PE and unknown, respectively. The results indicate that by moving away from the place of production of PES fibers, microplastics have undergone physical and chemical changes and their nature is changing. Results showed that the petrochemical industries can be potentially a microplastic source. It is a warning that if not taken into consideration will be a serious threat to environmental health.

Abstract 2,4-Dinitrotoluene (2,4-DNT) as a priority and hazardous pollutant, is widely used in industrial and military activities. In this study the synergistic effect of Fe–RGO–BiVO4 nanocomposite in a non-thermal dielectric barrier discharge plasma reactor (NTP-DBD) for degrading 2,4-DNT was evaluated. Preparation of the Fe–RGO–BiVO4 nanocomposite was done by a stepwise chemical method depositing Fe and reduced graphene oxide (RGO) on BiVO4. Field emission scanning electron microscopy (FESEM), X-ray diffraction analysis (XRD), UV–vis diffuse reflectance spectra (DRS), and energy-dispersive X-ray spectroscopy mapping (EDS-mapping) validated the satisfactory synthesis of Fe–RGO–BiVO4. To find the optimal conditions and to determine the interaction of model parameters, a central composite design (RSM-CCD) had been employed. 2,4 DNT can be completely degraded at: initial 2,4-DNT concentration of 40 mg L−1, Fe–RGO–BiVO4 dosage of 0.75 g L−1, applied voltage of 21kV, reaction time of 30 min and pH equal to 7, while the single plasma process reached a degradation efficiency of 67%. The removal efficiency of chemical oxygen demand (COD) and total organic carbon (TOC) were 90.62% and 88.02% at 30 min contact time, respectively. Results also indicated that average oxidation state (AOS) and carbon oxidation state (COS) were enhanced in the catalytic NTP-DBD process, which demonstrate the effectiveness of proposed process for facilitating biodegradability of 2,4-DNT.

Abstract Background In this study, the effect of static magnetic fields (SMFs) on improving the performance of activated sludge process to enhance the higher rate of microbial growth biomass and improve sludge settling characteristics in real operation conditions of wastewater treatment plants has been investigated. The effect of SMFs (15 mT), hydraulic retention time, SRT, aeration time on mixed liquor suspended solids (MLSS) concentrations, mixed liquor volatile suspended solids (MLVSS) concentrations, α-factor, and pH in the complete-mix activated sludge (CMAS) process during 30 days of the operation, were evaluated. Results There were not any differences between the concentration of MLSS in the case (2148.8 ± 235.6 mg/L) and control (2260.1 ± 296.0 mg/L) samples, however, the mean concentration of MLVSS in the case (1463.4 ± 419.2 mg/L) was more than the control samples (1244.1 ± 295.5 mg/L). Changes of the concentration of MLVSS over time, follow the first and second-order reaction with and without exposure of SMFs respectively. Moreover, the slope of the line and, the mean of α-factor in the case samples were 6.255 and, − 0.001 higher than the control samples, respectively. Changes in pH in both groups of the reactors were not observed. The size of the sluge flocs (1.28 µm) and, the spectra of amid I' (1440 cm−1) and II' (1650 cm−1) areas related to hydrogenase bond in the case samples were higher than the control samples. Conclusions SMFs have a potential to being considered as an alternative method to stimulate the microbial growth rate in the aeration reactors and produce bioflocs with the higher density in the second clarifiers.

Abstract Increased levels of nutrients and algae can cause drinking water problems in communities. Harmful algal blooms affect humans, fish, marine mammals, birds, and other animals. In the present study, we investigated the use of a combined system [Hydrodynamic Cavitation, Ozone (O3), and Hydrogen Peroxide (H2O2)] on the removal of Chlorophyll a and Organic substances in the raw water was investigated. The Effect of different operating conditions such as pH, cavitation time, pressure, distance, flow rate, ozone dose, and hydrogen peroxide concentration was studied. Utilizing the Taguchi design method, experiments were planned and optimized. The combined system treatment yielded a maximum reduction in Chlorophyll a and Total Organic Carbon (TOC) at an optimum condition of pH 5, cavitation pressure 5 bar, flow rate of 1 m3/h, a distance of 25 cm from the orifice plate, O3 3 g/h and 2 g/l of H2O2 concentrations. The most efficient factor in the degradation of TOC and Chlorophyll a, was cavitation pressure based on the percentage contributions of each parameter (38.64 percent and 35.05 percent, respectively). H2O2 was found to have the most negligible impact on degradation efficiency (4.24 percent and 4.11 percent, respectively).

Abstract The use of the kinetic coefficients for the mathematical expression of the biochemical processes and the relationship between the effective parameters is importance. Change of the biokinetic coefficients in the complete-mix activated sludge processes were calculated for 1 month operation of the activated sludge model (ASM) in a Lab-scale in three series. 15 mT intensity of static magnetic fields (SMFs) applied on the aeration reactor (ASM 1), clarifier reactor (ASM 2) and, sludge returning systems (ASM 3) for 1 h, daily. During the operation of the systems, five basic biokinetic coefficients such as maximum specific substrate utilization rate (k), heterotrophic half-saturation substrate concentration (K s ), decay coefficient (k d ), yield coefficient (Y) and, maximum specific microbial growth rate (μ max ) were determined. The rate of k (g COD/g Cells.d) in ASM 1 was 2.69% and, 22.79% higher than ASM 2 and, ASM 3. The value of K s (mg COD/L) was 54.44 and, 71.13 (mg/L) lower than the ASM 2 and, ASM 3. The rate of k d ASM 1, ASM 2 and, ASM 3 was 0.070, 0.054 and, 0.516 (d−1). The value of Y (kg VSS/kg COD) in ASM 1 was 0.58% and, 0.48% lower than ASM 2 and, ASM 3. The rate of μ max (d−1) in ASM 1 was 0.197, this value for ASM 2 and ASM 3 were 0.324 and 0.309 (d−1). Related to the biokinetic coefficients analyses the best location for the application of 15 mT SMFs was the aeration reactor, where the present of oxygen, substrate and, SMFs have the greatest impact on the positive changes of these coefficients.

Abstract This study evaluated the relationship between arsenic uptake via drinking water ingestion and arsenic concentration in fingernails as a biomarker for human exposure. For this purpose, we collected fingernail samples from 40 healthy participants of arsenic-affected rural regions of Kaboudrahang County, the west of Iran. A total of 49 fingernail samples were also collected from individuals who lived in areas where contamination of drinking water sources with arsenic had not been reported. It was found that the fingernails arsenic contents in 50 and 4.08% of the samples collected from arsenic-contaminated and reference villages were higher than the normal arsenic values of nails (0.43–1.08 µg/g), respectively. Based on the results of adjusted multiple linear regression, a significant association was found between groundwater and fingernails arsenic concentration (p 0.05). In light of the results of this study, the use of biological indicators such as fingernail tissues due to easier sampling and less risk of external contamination is suitable for assessing exposure to heavy metals in contaminated areas.

The current study was undertaken to determine the concentration of lead, cadmium copper, and zinc (Pb, Cd, Cu, and Zn) in three types of collected green leafy vegetables irrigated with contaminated water compared with those irrigated with the fresh water of Hamadan province, Iran using the inductively coupled plasma mass spectroscopy (ICP-MS) technique. Twenty samples of vegetables such as basil, leek, and lettuce irrigated with contaminated water, and twenty samples from five different adjacent areas irrigated with fresh water as control were analyzed to determine heavy metals (HMs). The highest mean concentration of Pb, Cd, Cu, and Zn, regardless of the kind of vegetables irrigated with contaminated water, was 0.95, 0.32, 3.03, and 13.58 mg/kg fresh weight, respectively. Moreover, metals uptake differences by the vegetables were recognized to vegetable differences in tolerance to HMs. The human health risk assessment indicated that non-carcinogenic values of Pb and Cd were higher than the threshold value of 1, and ingestion was the main exposure pathway of HMs to both children and adults. It suggested that all receptors (especially basil and lettuce) in Hamadan province might have significant and acceptable non-carcinogenic risk because of exposure to Pb and Cd. The significant amount of these HMs in some plants may be due to agricultural uses for the irrigation of the vegetable lands of untreated sanitary and industrial wastewater. The findings revealed that vegetables imply the total health risk on local people, and regular monitoring of HMs is strongly recommended in this region.

Background and Objective: Considering the importance of alkalinity in pH regulation and its buffering role, in this study, the effect of inlet wastewater alkalinity on the efficiency of the anaerobic unit of the wastewater treatment plant. Moreover, a superior chemical compound in providing alkalinity to wastewater was investigated. Materials and Methods: This study was performed in the treatment plant to determine the relationship between input alkalinity and removal efficiencies of COD, BOD5 and TSS. In order to determine the optimal alkali material for superb anaerobic wastewater performance, four common chemical substances including, NaOH, Na2CO3, Ca(OH)2 and MgO were selected and examined using One Factor At Time (OFAT) test method. Results: According to the results maximum removal efficiencies were obtained 62, 66.6 and 71.2% for COD, BOD5 and TSS, respectively under alkaline condition of 1260 mg/L CaCO3. Furthemore, the optimal dose to supply one unit of alkalinity by Na2CO3, Ca(OH)2 and MgO were 0.53, 0.54 and 0.3 mg/L, respectively. These values were obtained 5 min contact time and mixing rate of 150 rpm. However, for NaOH the optimal dose supply was obtained 0.35 mg/L for 3 min contact time and mixing rate of 100 rpm. Conclusion: In conclusion, the performance of anaerobic baffled reactor is highly related to the supply of influent alkalinity to the reactor. In addition, the use of MgO can be considered as a suitable alkaline substance to neutralize acidic wastewater and provide alkalinity for ABR system.

The combination process of UV/ S2O82-/Al2O3 leads to the production of radicals and radical hydroxyls, which could decompose and remove various pollutants, such as phenol. The present study aimed to investigate the photocatalytic efficiency of aluminum oxide nanoparticles and persulfate compilative processes in the removal of phenol. This experimental study was conducted in a discontinuous reaction chamber with a useful volume of one liter. In this process, we assessed the effects of the initial pH parameters (3, 5, 7, and 9), initial concentration of phenol (10, 20, 30, 50, and 100 mg/l), concentration of persulfate anions (20, 30, 40, 50, and 60 mg/l), reaction time (5 and 120 minutes), and dose of Al2O3 nanoparticles (10, 20, 30, and 40 mg/l). The applied pilot was composed of a low-pressure mercury lamp (55 Watt), which was inside the steel chamber. The obtained data were fitted to the pseudo-first- and pseudo-second-order reaction kinetics. According to the findings, the process had high efficiency in the removal of phenol. In optimal conditions (pH:5, persulfate concentration: 50 mg/l, nanoparticle dose: 40 mg/l, reaction time: 60 minutes), the efficiency of the process was determined to be 95% at the initial phenol concentration of 10 mg/l, which was fitted with first-rate kinetics (R2=0.98). Furthermore, the highest efficiency was observed in the photocatalytic process of aluminum oxide nanoparticles and persulfates in the optimal conditions of exploitation. Therefore, persulfate could be used as an appropriate oxidizer with aluminum oxide nanoparticles for the removal of phenol.

Background and Objective: Urinary tract infection is the second most common cause of infection in the human body. Among the causes of urinary tract infection, Escherichia coli is the most common bacteria causing the urinary tract infection in both genders (male and female). Therefore, the aim of this study was to determine the antibiotic resistance pattern of bacteria causing urinary tract infection in the urine culture samples of the Shahid Beheshti Hospital Laboratory in Hamadan during 2016-2017. Materials and Methods: This descriptive cross-sectional study was conducted based on a purposive sampling for 16 months from April 2016 to July 2017 in Shahid Beheshti Hospital, Hamadan. In this study, urine specimens were collected by Midstream Clean Sugar method and then cultured in two Blood Agar and EMB culture mediums using standard loop. Results: The results showed that, out of 1400 urine samples from outpatients referring to Shahid Beheshti Hospital in Hamadan, 235 were positive, of which 105 cases (44.7%) were related to men and 130 cases (55.4%) were women. Escherichia coli isolated with 141 (60%) cases was the most common organisms. Most of Escherichia coli isolates (126 cases) were resistant to ciprofloxacin antibiotic and only 1 case of resistance to Carbenicillin was observed. Conclusion: In general, the results showed that the most common bacterial agent of urinary tract infection was Escherichia coli and the highest cases of this isolate were resistance to ciprofloxacin. In addition, the highest antibiotic susceptibility was related to Nitrofurantoin.

In this study, qualitative characteristics of the sludge produced in Hamadan wastewater treatment plant and the feasibility of its application in agricultural lands were investigated. Samples were taken from the primary and secondary sludge and indices such as VS/TS, PH, TKN, COD, TKN, SOUR, Na, Ca, SAR, heavy metals and biological properties (the mean fecal coliform count and the number of parasitic eggs) were measured. The results were compared with the United States Environmental Protection Agency (US EPA) standards (40 FCR-503). The results showed that the VS/TS ratio of the raw sludge was 0.8, 0.55, and 0.55 and that of the secondary sludge was 0.65, 0.28, and 0.32 for fall, winter, and summer, respectively. The average concentration of COD, TKN, SOUR, Na, and Ca for the initial sludge was 51283, 107, 0.50, 609, and 952 and for secondary sludge, it was 35595, 81, 4.90, 306, and 493 mg/L, respectively. The MPN for primary and secondary sludge was determined to be 19.83 × 106 and 186 × 106 , respectively and the average number of parasite eggs in primary and secondary sludge was 7.05 and 7.2 in 4 g of dry solids. Entamoeba coli had the highest number of parasite. The results of this study showed that the highest concentration of heavy metals in the sludge was 21396 mg/kg. The values obtained for the above-mentioned indices and heavy metals were in standards range. The results of this study show that none of the primary and secondary sludge samples has been properly stabilized. The values obtained for biological characteristics of sludge were not in the standard range. Therefore, it was revealed that the use of sludge for agriculture needed more stabilization.

It has been documented that arsenic has a potential risk to human health and identified as a risk factor for hearing impairment. However, there are few studies that confirm the ototoxic effect of arsenic, especially on the human auditory system. Therefore, the current study was conducted to investigate the correlation between auditory thresholds at different frequencies (0.25, 0.5, 1, 2, 4 and 8 kHz) and arsenic levels in drinking water samples. A total of 240 people, divided into two equal groups: exposed and reference, were selected for the auditory tests. It should be noted that, at frequencies from 0.25 to 1 kHz, no hearing loss was observed in the both groups. Based on the results, no significant correlations (p > 0.05) were found between hearing thresholds and confounding variables including gender and BMI. However, smoking and age are known to be the main variables for hearing loss in univariate regression analysis. In the case of age, the hearing loss risk in the older participants was increased compared with the younger participants (4 kHz (OR =1.09; 95% CI: 1.04, 1.13) and 8 kHz (OR =1.12; 95% CI: 1.06, 1.18)). Smoking habits had significant associations with hearing loss risk at 4 kHz (OR = 3.48; 95% CI: 1.47, 8.22) and 8 kHz (OR = 3.01; 95% CI: 1.14, 7.95). The multivariate regression analysis showed that age, smoking status, and exposure to arsenic were significantly associated with increased risk of hearing loss. Moreover, no statistically significant correlation (p˃0.05) was observed between arsenic exposure and hearing loss in the logistic regression model compared to the reference group. These outcomes suggest that further investigation and cohort studies with a larger number of participants should be conducted to find an association between arsenic exposure and hearing loss in general population.

Pentachlorophenol is one of the resistant phenol compounds has classified in the group of the primary pollutants due to its high toxicity and carcinogenic potential. The aim of this study is determining the efficiency of advanced oxidation process method using O3/H2O2 in the presence of TiO2 and ZrO2 nano-particles stabilized on pumice for the removal of PCP from aquatic solutions. This experimental study was performed in a batch reactor at laboratory scale. In this study, the effects of reaction time, initial concentration of PCP, pH, concentration of catalysts and H2O2 and also the amount of decline in chemical oxygen demand (COD) after the process were investigated. The concentration of PCP in the sample was determined using spectrophotometer at wavelength of 500 nm and, in the end, the results were analyzed using SPSS software and according to repeated measures analysis and statistical test of comparative ordered pairs with confidence interval of 95%. Scanning electron microscope (SEM), fourier transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD) images of modified pumice were taken and the kinetic degree of the processes was also determined. The results indicated that the PCP removal by the both processes increased with increasing reaction time, catalyst concentration, H2O2 concentration and pH and reduced with decreasing initial PCP concentration. The maximum removal efficiencies by the two processes: O3/nZrO2/H2O2 and O3/nTiO2/H2O2 were 100 and 95%, respectively, in the optimum conditions. The results illustrated that the two studied processes followed the pseudo-second -order kinetic model. Further, the findings revealed that the both processes mentioned in this study were of high capability in removing PCP and they could be used as an appropriate process in removing this organic material.

Abstract Furfural is a toxic chemical compound that is widely applied as a solvent in a great many of industries, and it can cause many problems to the human beings and environment. Various methods of removing furfural from the wastewaters have been studied. AOPs methods are utilized for the elimination of a vast majority of the pollutants due to their high efficiency as well as for their lack of creating secondary contamination. Therefore, the present study aims at comparing the efficiency of UV/ZrO2 and UV/H2O2/ZrO2 photocatalytic processes in removing furfural from aqueous solutions. The solution’s initial pH, furfural’s concentration, zirconium catalyst dosage and time were investigated as the parameters influencing the removal efficiency by the two foresaid processes, and the effect of H2O2 addition in various concentrations into UV/H2O2/ZrO2 process was also evaluated. Spectrophotometer device was employed to assay the concentration of the residual furfural. The results indicated that the pH of the environment, the amount of the nanoparticle and H2O2 input concentration largely influence the furfural omission. The optimal condition for the removal of furfural in UV/ZrO2 process in an initial concentration of 20 mg/L, a pH equal to 3, a catalyst dose of 0.25 g/L during a period of 60-min time was 81.6%, and it was 99% for UV/H2O2/ZrO2 process in a pH equal to 7 with the addition of H2O2 for a concentration of 0.75 mL/L under the same conditions. Generally, it can be concluded that UV/H2O2/ZrO2 and UV/ZrO2 photocatalytic processes can effectively be applied to remove furfural from the aqueous solutions, especially in lower concentrations.

Introduction and Aims: Pharmaceutical pollutants in aqueous can cause a number of health problems for people and other creatures. In this study, a survey of Dexamethasone removal from synthetic aqueous solutions was investigated by using UV/S2O8 and UV/H2O2 methods. Materials and Methods: This experimental study carried out at lab scale at a reactor with the batch flow. In this study, the parameters of time (5- 60 min), pH (3, 7 and 11), dose of S2O8 (0.1-7.5 mM), dose of H2O2 (0.1- 7.5 mM), and Dexamethasone concentration (5- 20 mg/L) were studied to specify their effects on Dexamethasone removal. Furthermore, the remaining concentration of dexamethasone was determined by spectrophotometer DR (model 5000) in the 241 nm wavelength. Results: Results showed that with the increasing amount of parameters of pH, retention time, and a dose of H2O2 and S2O8 and with decreasing parameter of dexamethasone concentration, removal efficiency raised. Removal efficiencies of dexamethasone in the optimum condition of time=40, pH=3 and dexamethasone concentration = 5 mM was obtained 47, 59, 82, 91, and 98 percent for UV/S2O8 concentrations of 0.1, 0.5, 1.5, 5, and 7.5 mM, and 19, 49, 61, 65, and 72 percent for UV/H2O2, respectively. Conclusion: According to higher removal efficiencies of UV/S2O8 method than UV/H2O2, easier storage and moderate stability of S2O8 and also more oxidation ability of SO4- than OH°, it is better to apply UV/S2O8 method to degradation of dexamethasone.

Background and Objective: Due to increasing the water demand and the lack of its resources, the reuse of effluents is considered as a useful option in the water resources management. The aim of this study was to evaluate the possibility of the reuse of effluents from the extended aeration process in the wastewater treatment plant of the Bojnoord city for agricultural uses. Materials and Methods: This is a descriptive-analytical study which performed in 2013 on the quality of effluents in the wastewater treatment plant of the Bojnoord city by measuring the parameters of Electrical Conductivity (EC), Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), nitrogen, phosphorus, Total Suspended Solids (TSS), Total Dissolved Solids (TDS), Sodium Adsorption Ratio (SAR), sodium percentage, magnesium ions, potassium ions, calcium ions, sodium ions and chloride. Results: The results shown that, the removal efficacy of BOD and COD were 88% and 89%, respectively, and it was higher than 85 percent for TSS and VSS factors; thus, the average residual concentration of BOD, COD, TSS and phosphate in the outflow were 27, 61, 26 and 11.34 mg, respectively. The average values of pH and EC in treated effluent were obtained 7.45 and 1940 μs/cm, respectively. Moreover, the values of chloride and SAR for the effluent of the wastewater treatment plant of the Bojnoord were achieved 3.89 meq/L and 221 mg/L, respectively. Conclusion: based on the results, it can be concluded that the effluents of the wastewater treatment plant of the Bojnoord city can be valuable for use in agriculture; but, due to the high concentration of chloride in treated effluent, it is recommended that this effluent used for semi-sensitive plants. Furthermore, this effluent is not suitable for feeding to groundwater and for discharging into the surface water and it is needed to advanced treatment based on the standards.

Erythrosine B is widely used for dyeing in various applications, especially in the food industry, despite its already proved toxicity and carcinogenicity. Therefore, the purpose of this study is to evaluate the efficiency of the synthesis process of US/S2O8-2 in removing erythrosine B dye from aqueous solution. In this experimental study, the removal of erythrosine B dye using combined persulfate and 40 kHz ultrasound process was studied. All reactions was conducted in a beaker of 1,000 mL in an ultrasonic bath. The effects of operational parameters such as pH of the solution (3-7), initial concentration of erythrosine B dye (10–100 mg/L), and amount of persulfate concentration (0.001–0.005 mol/L) in different contact time were investigated. The results showed that the removal efficiency increased significantly by increasing the oxidant concentration, then a steady trend was observed in the removal of erythrosine B dye. The process used US/S2O8-2 at pH:3, concentration of persulfate at 0.003 mol/L, and the time of 60 min for achieving the highest removal efficiency (98.91%). Ultrasonic device alone had little effect in the removal of this dye. The effects of ion changes from calcium chloride on the performance of the US/S2O8- process were ineffective for erythrosine B dye. The results of the US/S2O8-2 process application in the removal of erythrosine B dye indicated that this process has a suitably proper ability for erythrosine B dye removal and could be used as an effective method for industrial wastewater treatment.

Background: Due to their polycyclic and toxic structure, dyes have a high ability in causing adverse acute and chronic effects on human exposed to them. In present study, the decolorization of acid green3 from aqueous solution by UV/ H2O2 method was investigated Methods: This is an applied-experimental study. Parameters of pH in the amount of 3,7 and 11, contact time in 5,15, 30, 45 and 60 min, dose of H2O2 in 10, 30 and 50 mg/l and initial concentration of acid green3 in 50, 100 and 150 mg/l were examined to reveal the optimum amounts of these parameters. In order to emit the UV radiation, photo reactor with a 2-lit volume was applied, also to measure remaining concentration of dye, spectrophotometer device, model DR 5000 was employed. Chemical oxygen demand (COD) test based on 5220C method (standard method book) was used for determining amount of oxidation. Results: Results showed that contact time = 60 min, pH=7, acid green concentration=50 mg/l and dose of H2O2 =30 mg/l are optimum condition at which the removal amounts of dye and COD were obtained about 97 and 85%, respectively. Conclusion: In the study, it is observed that parameters of contact time, pH, initial concentration of dye, and dose of H2O2 have a significant influence on the removal of the dye by UV/H2O2 process. Due to acceptable results of UV/H2O2 in the oxidation of the dye and the reduction of COD, this method can be introduced as reliable process to remove of acid green 3 from industrial wastewaters.

The presence of pharmaceutical wastewater containing antibiotic compound is one of the new problems relating to the environmental pollution. Antibiotic ciprofloxacin (CIP), widely used in medical treatments, can induce antibiotic resistance in low concentrations in the ecosystem and aqueous solutions. In this study, CIP was removed using moving bed biofilm reactor (MBBR) from real hospital-derived wastewater. This study was carried out at Beasat hospital in Hamadan, Iran. CIP (100 mL) was applied in 2 sets of plexiglass tubular columns as MBBR. Microorganisms were grown on the suspended carriers. To achieve this purpose, polyethylene kaldnes (K1) was chosen as reactor bed in 500 m2 /m3 specific area. The effect of operating parameters such as mixed liquor suspended solid (MLSS) (100, 1000, 3000 mg/L), hydraulic retention time (HRT) (8, 12, 24 hours), and support media with carrier K1 (30%, 50%, 70%) were evaluated. According to the results, the yield of CIP removal at 30%, 50%, and 70% of K1, reaction of 24 hours at MLSS 3000 mg/L was obtained 50.5%, 68.9%, and 97.6% respectively. In the same conditions, chemical oxygen demand (COD) removal was achieved 26.78%, 30.49%, and 80.07%, respectively. Results indicated that the MBBR process can be used as an effective approach for removing CIP and COD from hospital effluent. Moreover, these data suggested that the K1 carrier could be useful in terms of mineralization and efficiency. Furthermore, development of biofilm in MBBR was mostly affected by K1.

Introduction: Organic compounds are one of the most important quality characteristics in wastewater treatment. The aim of this study is to make comparison of the efficiency of wetland and extended aeration activated sludge in the removal of organic compounds from sanitary wastewater based on response surface methodology. Methods: In this experimental study 100 mixed samples were taken from wetland and extended aeration reactors. According to type of wastewater treatment and operating time, COD, BOD5 and TSS were measured. Sampling, transportation, storage and measurement performed according to standard methods. Experiment setting, modeling, removal equation of organic compounds and optimal condition was obtained by response surface methodology. Results: Maximum removal of COD, BOD5 and TSS (in summer) in wetland were 95.67, 93.4 and 87.41%; in extended aeration was 97, 65.1 and 80.2%, respectively. Efficiency of extended aeration was better than wetland in all seasons and all parameters. R2: 0.8- 0.89 confirms the effect of operating time on wastewater treatment efficiency. Validity and accuracy in wetland and extended aeration were 12.64-17.65 and 16.01-19.37, respectively. Removal model in both wetland and extended aeration was linear. Conclusion: Efficiency of extended aeration is more than wetland. Response surface methodology properly describes organic compound removal efficacy by extended aeration and wetland.

The Necessity of Monitoring Pesticide Residues in Vegetables and Fruits Using Hazard Index among Consumers

Background and purpose: Using catalysts to enhance the efficiency of the ozonation process (known as catalytic ozonation process) has received much attention in recent years. This study aimed at examining the overall feasibility of using catalysts ozone as catalyst in ozonation process for decolorization and mineralization of a real textile wastewater in presence of persulfate. Materials and methods: This experimental study was conducted on a laboratory scale reactor using a semi-batch mode. The effect of persulfate, ozone flow rate, reaction time and catalytic dose in dye and COD was investigated in an optimal state of textile wastewater. To obtain optimization test, the experiment was performed by fractional factorial method at three-level factorial (3k−p) with a high resolution (VI). Results: In this study, 15 min contact time (P = 0.006) and 0.5g/L dose of catalyst (P=0.029) had the best effect on color removal. Moreover, the interaction of these parameters were found to be significant (P= 0.025). The optimum condition for color removal was achieved at 15 min reaction time, ozone flow rate of 2 L/min, 1.5 mM persulfate and catalyst dosage of 0.5 g/L. Optimum efficiency removal for color and COD in textile wastewater were 96% and 75%, respectively. Conclusion: Application of nano-magnesium oxide with ozone in presence of persulfate showed synergistic effect and buffering property in decolorization and mineralization of textile wastewater. It also increases the efficacy of color removal and improves mineralization so, there would be no need for pH adjustment.

Ciprofloxacin is an antibiotic vastly administrered for the treatment of infections. A major paortion of the drug remains non-metabolized and is excreted to find its way ultimately into water environments through discharge into wastewater. Although carbon nanotubes have been widely employed for the removal of contaminants, ciprofloxacin still poses problems against its proper removal. It is the objective of the present study to synthesize magnetite Fe3O4/MWCNTs and to evaluate its performance in ciprofloxacin removal via the heterogeneous Fenton process. For this purpose, the performance of the synthesized nanocomposite was evaluated while the effects of the following parameters were also investigated on the heterogenous Fenton process under lab conditions: pH, 4‒10); adsorbent quantity, 1‒3 g/l; initial antibiotic concentration, 30‒200 mg/l; contact time, 15‒300 min; and H2O2 concentration, 5‒25 μmol/l. Moreover, the synthesized Fe3O4/MWCNTs was morphologically and microstructurally characterized using Transmission Electron Microscopy (TEM) and X-ray diffraction (XRD) while the formation of carboxylic functional groups was verified by Fourier transform infrared spectra (FT-IR). It was found that the efficiency of the heterogeneous Fenton process for the removal of ciprofloxacin at a concentration of 30 mg/l was 95% in approximately 180 minutes and a molar ratio of 1 ml H2O2/2g Fe. Based on the results obtained, the Fe3O4/MWCNTs magnetite nanocomposite is well capable of removing ciprofloxacin from aqueous solutions in the heterogeneous Fenton process.

Phenol is a toxic hydrocarbon that has been found in the wastewater of several industries, including the petroleum and petrochemical industries. The discharge of untreated wastewater from these industries causes environmental pollution, especially in water. The aim of this study was to evaluate the efficiency of phenol removal from wastewater using a biofiltration system. In this experimental study, a cylindrical plexiglass biofilter reactor with an effective volume of 12 liters was used. A total of 30 pcs of plastic grid discs were placed inside the reactor by plastic pipes to maintain the biofilm media in the reactor. The microorganisms used in this study were obtained from the biological sludge of a municipal wastewater treatment plant. The reproduction and adaptation of the microorganisms to 500 mg/L of phenol lasted three months. The effects of pH, phenol, nitrogen, phosphorus, glucose concentration, and hydraulic retention time on the biofilter system’s performance was evaluated. The results of this study showed that in optimal conditions, this system can reduce the phenol concentration from 500 mg/L to zero within about 4 hr. Maximum efficiency occurred in pH = 7, and the proper COD/N/P ratio was 100/10/2, respectively. In general, this biofilter system is capable of removing 500 mg/L of phenol concentrations and an organic load of 4 - 4.5 kg COD/m3.d within 4 - 5 hr. with high efficiency.

Background: This study aimed to investigate the biosorption of pentachlorophenol on Aspergillus niger biomass as a method for removal of pentachlorophenol from aqueous solutions. Methods: Modified A. niger biomass with NaOH was used to absorb the pentachlorophenol. The impacts of various experimental parameters like primary pentachlorophenol concentration, pH of the solution, contact time, and biomass dosage on the biosorption of pentachlorophenol were investigated. Results: The correlation of contact time, pH and initial concentration with the biosorption of pentachlorophenol by A. niger biomass was statistically significant (P

Hospital wastewater is of great environmental concern because it contains a variety of hazardous microbial and chemical substances. This study aims to investigate the efficiency of a moving bed biofilm reactor (MBBR) with a light expanded clay aggregate (LECA) carrier for treating hospital wastewater. This pilot study used a Plexiglas reactor that had a volume of 100 L, a continuous up-flow hydraulic regime, and a LECA carrier to test removal of chemical oxygen demand (COD) from wastewater in a public hospital. To assess MBBR efficiency, the study used retention times of 8, 12, and 24 hours, filling percentages of 30% and 50%, and mixed liquor suspended solids (MLSSs) of 1000, 3000, and 5000 mg/L. The results indicated that using a single LECA carrier in an MBBR system was not sufficient to remove organic materials from hospital wastewater, because the carrier could not be completely suspended. After some modifications, consisting mainly of returning activated sludge, the system was 83% efficient at removing COD using a LECA carrier at a retention time of 24 hours, with 50% filling, and 5000 mg/L of MLSS.

Background and purpose: Stability and sustainable [s1] of emerging synthetic compounds such as Dimethyl phthalate lead to increasing their concentrations in environment and food chain and health risks. Therefore, researchers are concern to achieve effective and efficient methods for removal these pollutions. This aim of this study was to evaluation of the efficiency of heterognous Fenton using Zero-valent iron nanoparticles in dimethylphthalate removal from aqueous solutions. Materials and Methods: This experimental study was conducted in laboratory scale in batch reactor. The effects of operational parameters such as reaction time (15 to 120 min), pH (2 to10), H2O2 concentrations (0.01 to 1 mmol/L), nZVI dose (0.01 to 0.5 mg/L) and initial concentrations of Dimethyl phthalate (2 – 50 mg /L) determined by one at a time method. Then effect of each heterogeneous Fenton regent was determined in dimethyl phthalate removal. Results: The results showed that maximum efficiency of heterognous Fenton process in dimethylphthalate removal occur at pH=4. Also at H2O2 concentration 0.1 mmol/L, nZVI dose 0.05 g/L, Dimethyl phthalate concentration 2 mg/L and reaction time 120 minute, amount of Dimethyl phthalate removal was 92.8%. Conclusion: According to the results, nZVI- heterognous Fenton process has appropriate efficiency in Dimethyl phthalate removal from aquatic solutions and can be assumed as an effective and applied method for removal similar compounds from industrial wastewater.

زمینه و اهداف: یکی از فلزات بسیار سمی در فاضلابهای صنعتی کروم شش ظرفیتی (VI) میباشد که بعنوان یک عامل کارسینوژن، موتاژن و تراتوژن شناخته میشود. در این مطالعه توانایی بیومس مرده تولید شده از قارچ آسپرژیلوس ترئوس در حذف کروم (VI) از محیطهای آبی مورد بررسی قرار گرفت مواد و روشها: سوسپانسیون قارچ آسپرژیلوس ترئوس در محیط های کشت پوتیتو دکستروز آگار و پوتیتو دکستروز براث کشت داده و سپس در محلول 0.5نرمال NaOH جوشانده شد. توانایی جذب بیومس حاصل برای متغیرهای زمان 15) تا 120 دقیقه(، 3) pH تا (11، غلظت کروم 20)(VI) تا (120 mg/L و دوز جاذب 0.1) تا 0.8g) مورد بررسی قرار گرفت. از دستگاه جذب اتمی مدل Varian جهت سنجش کروم(VI) استفاده شد. موازین اخلاقی در انجام این پژوهش و استفاده از منابع رعایت گردید یافته ها : نتایج نشان داد که فرآیند جذب در زمان تماس 90 دقیقه، pH برابر با 7 ، غلظت آلاینده20 mg/L و دوز جاذب 0/6 g، دارای راندمان حذف برابر با 89 درصد میباشد. همچنین فرآیند جذب از ایزوترم فرندلیخ با R2=0.952 و سینتیک شبه درجه اول با R2=0.9775 پیروی می نماید. نتیجه گیری: نتایج نشان داد که متغیرهای مورد مطالعه اثر قابل توجهای در راندمان جذب دارند، بطوریکه در شرایط بهینه، بیومس قارچ آسپرژیلوس ترئوس دارای راندمان و ظرفیت جذب قابل قبولی در حذف کروم (VI) در مقایسه با سایر جاذبها است. در نتیجه میتوان این ترکیب را بعنوان یک جاذب طبیعی جهت حذف کروم (VI ) و سایر فلزات سنگین از محیطهای آبی معرفی کرد

Background and Objectives: Pentachlorophenol (PCP) is an organic compound and phenolic derivatives categorized as priority pollutants that have harmful effects on humans, animals, and plants in low concentrations. Therefore, PCP removal from water and wastewater is very important. The aim of this study was to assess the efficiency of A. niger fungus biomass in PCP absorption. Materials and Methods: This was an experimental study in which different steps of the experiments were performed. A. niger strain was prepared from Persian Type Culture Collection of Iranian Research Organization for Science and Technology (IROST). After activation in potato dextrose agar (PDA) culture plates, fungi were incubated for 7 to 10 days at 25 °C. The prepared A. niger biomass was modified by NaOH and then it was used for PCP absorption assay. The concentration of PCP was measured using high-performance liquid chromatography. Results: The findings of present study showed that contact time is an important and effective factor in the PCP absorption rate. Two hours was selected as the optimum retention time in this experiment and after that the removal percentage did not raise significantly. The results of PCP absorption in different pH demonstrated that the adsorption efficiency decreases by rising pH and initial PCP concentration. The effects of contact time, pH and initial PCP concentration on the absorption process was significant (P-value

Background and purpose: Stability of new synthetic compounds such as Dimethyl phthalate increased their concentration in the environment and food chain and caused health risks. Therefore, achieve effective and efficient methods to removal of pollutants are one of the environmental researchers concern. This study investigates efficiency of heterognous Fenton process using nZVI in dimethylphthalate removal from aqueous solutions. Materials and Methods: This experimental study was conducted in batch reactor in laboratory scale and the efficiency of heterognous Fenton process was analyzed in a batch system with the effect of changes in operating parameters such as reaction time (15 to 120 min), pH (2 to10), H2O2 concentration (0.01 to 1 mmol/L), nZVI dose (0.01 to 0.5 mg/L) and initial concentration of Dimethyl phthalate (2 – 50 mg /L). Then the effect of each heterogeneous Fenton regent in dimethyl phthalateremoval was determined. Results: The results showed that the maximum efficiency of heterognous Fenton process in removal of Dimethyl phthalate is at pH=4. Also in optimal conditions, the parameters affecting reaction was determined as H2O2 concentration 0.1 mmol/L, nZVI dose 0.05 gr/L, Dimethyl phthalate concentration 2 mg/L and 120 minute, amount of Dimethyl phthalate removal was 92.8%. Conclusion: According to the results, heterognous Fenton process using nZVI has an optimal efficiency in removal of Dimethyl phthalate from aquatic solutions and can be considered as an acceptable and low Cost method for the removal of similar compounds.

Introduction: Industries are textile wastewater contains large amounts of color can create a lot of pollution. There are different methods for decolorization of textile industries, for example the methods of coagulation, flocculation, chemical oxidation, biological treatment, electrochemical techniques, including ion exchange and other processes. The purpose of this study was to compare the efficacy of alum and ferric chloride is used to remove dye Disperse Blue 56.Material and Methods: The research was according to the method Jar test. The sample pH was adjusted using NaOH and sulfuric acid 0.1 normal. Coagulants with different concentrations were added to each sample. A minute of high speed and slow speed were mixed for 15 minutes and after deposition, sample pH and absorbance values were measured. The dye concentration in the samples was measured by spectrometry method using a UV-1700 Pharmaspec Shimadzo spectrophotometer at 550 nm wavelengh.Results: Coagulation by alum to remove dye Disperse Blue has a pH optimum of 6 and optimal dose of 130 milligrams per liter, which is the pH and the optimal dose has a removal efficiency of 93 percent, while for Chloroferric the pH optimum of 9 and optimal dose of 120 milligrams per liter with removal efficiency over 98 percent.Conclusion: The results showed that the coagulation process using a lot of blue disperses dyes in textile wastewater removed from the wastewater. The results showed that the coagulant is alum Chloroferric has better removal efficiency.

Simultaneous presence of various antibiotics and bacteria in hospital wastewaters creates a suitable environment, in which the bacteria, such as ‎enterococci become resistant to the antibiotics. The aim of this study was to evaluate the performance of different units of the hospital wastewater treatment plant (HWTP) to remove Enterococcus spp and Vancomycin-resistant Enterococcus (VRE). The study was performed on the 27 samples collected from HWTP in Hamedan, Iran during December 2014 to August 2015. Enterococcus spp and VRE were identified by biochemical tests and then the isolates were confirmed by PCR. Finally, the antibiotic susceptibility test was performed using disk diffusion methods. Of the 27 samples examined, 315 a total of enterococcal isolates were obtained. Of the 315 isolates of enterococci investigated, 162 (51.42%) were identified as E. faecium, 87 (27.61%) as E. hirae, 35 (11.11%) as E. faecalis, 11 (3.5%) as E. gallinarum, 7 (2.22%) as E. casseliflavus, 4 (1.26%) E. avium, and 9 (2.85%) isolates VR E. faecium.The results of antibiotic susceptibility testing showed that of the total 315 isolates, 146 (46.34%) were resistance to tetracycline, 9 (2.85%) were resistance to vancomycin and Teicoplanin. Lower antibiotic resistance was seen with Nitrofurantoin 2 (1.26%). This study indicates a high prevalence of multidrug resistance among E. faecium isolated from HWTP, thus, it could be considered as a threat to the health and safety of ‎wastewater workers and even public health.

In this study, the performance of a pilot-scale vermifilter (VF) for the treatment of hospital wastewater using the earthworm species Eisenia fetida was evaluated. The earthworms’ gut acts as a bioreactor and can ingest the wastewater solid and liquid organic wastes and expel these as vermicompost. A pilot-scale vermifilter was installed and operated for 133 days in one of hospitals in Hamadan city; the designed system was fed with the influent passed through coarse and fine grillage and the sedimentation tank of the hospital’s sanitary collection system. In order to study the efficiency of the system, the variations of pH value, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), and total suspended solids (TSS) were measured. In addition, a conventional geofilter (GF) without Earthworm was used as the experimental control. The vermifiltration caused a significant decrease in the levels of COD (75%), BOD5 (93%), and TSS (89%) as well as neutralized pH in the wastewater. Also, these contents in the geofilter were observed to be 65%, 71%, and 71%, respectively. The vermifiltration technology can, therefore, be applied as an environmentally friendly method for hospital wastewater treatment.

Considering extensive applications of manganese tetroxide nanoparticles in various industries due to its special properties, conducting studies on how to achieve more suitable ways to produce smaller nanoparticles is of great importance. In this study, nanoparticles of manganese tetroxide (Mn3O4) were synthesized by a co-precipitation method. In order to determine the characteristics of the structure, size, and specific surface of the resulting nanoparticles, techniques such as XRD, BET, BJH, FESEM, and FTIR were employed. Also, the nanoparticles were quantified with EDS and their colony size was examined using DLS experiments. The findings revealed a production of crystalline manganese tetroxide nanoparticles with a space group of 141/amd (S.G.) (141) and a molecular weight of 228.81 with the international code of ICSD Card # 89 - 4837. The specific surface area was 32.147 m2/g with a pore volume of 0.1041 cm3/g. The XRD and EDX analyses verify the production of the Mn3O4 nanoparticles. The size of the nanostructures is approximately 19 nm. The method used in this study could produce the Mn3O4 nanoparticles in a much easier way without the need for surfactants. Compared to the nanoparticles produced in other studies, the size of the nanoparticles produced in the present study is remarkably smaller. Moreover, less amount of the metal salt was used.

Background: The objective of this study was to determine the residual concentrations of ethion and imidacloprid in cucumbers grown in greenhouse. The effect of some simple processing procedures on both ethion and imidacloprid residues were also studied. Methods: Ten active greenhouses that produce cucumber were randomly selected. Ethion and imidacloprid as the most widely used pesticides were measured in cucumber samples of studied greenhouses. Moreover, the effect of storing, washing, and peeling as simple processing procedures on both ethion and imidacloprid residues were investigated. Results: One hour after pesticide application; the maximum residue levels (MRLs) of ethion and imidacloprid were higher than that of Codex standard level. One day after pesticide application, the levels of pesticides were decreased about 35 and 31% for ethion and imidacloprid, respectively, which still were higher than the MRL. Washing procedure led to about 51 and 42.5% loss in ethion and imidacloprid residues, respectively. Peeling procedure also led to highest loss of 93.4 and 63.7% in ethion and imidacloprid residues, respectively. The recovery for both target analytes was in the range between 88 and 102%. Conclusion: The residue values in collected samples one hour after pesticides application were higher than standard value. The storing, washing, and peeling procedures lead to the decrease of pesticide residues in greenhouse cucumbers. Among them, the peeling procedure has the greatest impact on residual reduction. Therefore, these procedures can be used as simple and effective processing techniques for reducing and removing pesticides from greenhouse products before their consumption.

Cyanide is a highly toxic species that found mostly in industrial effluents such as electroplating, metal mining, metallurgy and metal cleaning processes. Discharge of it into the enviroment causes very health impact. Purpose of this study was, determination of sonochemical technology for cyanide removal from aqueous solutions in the presence of hydrogen peroxide. In this study, a productive set of 500w power ultresoun waves with two frequencies 35 kHz and 130 kHz were used. Experiments were performed using different initial ratio CN-/H2O2 1/1, 1/3 and 1/5 and at initial cyanide concentrations varying from 2.5 to 75 mg/L. The effects of parameters such as pH, time and initial cyanide concentration on the sonochemical degradation have been studied. The results of the study showed that the maximom removal efficiency of cyanide was achieved 85% by sonochemical technology at frequency of 130 kHz, during of 90 min, at pH of 11, at initial cyanide concentration of 2.5 mg/l and with initial ratio of CN-/H2O2 1/5. it was also found the rates of cyanide degradation under different conditions were quite low, and also the rate of cyanide degradation was high at first but later substantially reduced. The efficiency of cyanide removal had direct relationship with pH, frequency, hydrogen peroxide concentration and time ,and it had reverse relationship with cyanide concentration.

For the purposes of this study, activated carbon was derived from pine-cone by a chemical-thermal process. Initially, its chemical and physical properties were determined before it was used for the removal of Acid Black 1 and Acid Blue 113 dyes. A batch sorption study was carried out in order to obtain the optimum isotherm model. The monolayer maximum saturation capacities of AB1 and AB113 dyes based on Langmuir isotherm model were determined to be 458 mg dye/g carbon and 286 mg dye/g carbon, respectively. Adsorption of dyes was also studied in a continuous-flow state using a fixed-bed column of activated carbon. The effects of operating variables such as flow rate, bed depth, and dye concentration on the column operation were studied. Data confirmed that the breakthrough curves depended on flow rate, bed depth, and initial dye concentration. Column behavior was investigated using Thomas Model and model parameters were determined by a non-linear regression method. The Langmuir and Freundlich isotherm models were used to fit the experimental data. The best fit of the adsorption isotherm data was obtained using the Langmuir model for both dyes. The results showed that Thomas Model was suitable for the description of breakthrough curves under the experimental condition. The column adsorption capacity was also compared with equilibrium adsorption capacities for each dye.

Phenol or Benzene hydroxyl, is a toxic aromatic hydrocarbon which finds its way into the environment and water resources as a serious environmental hazard in the effluent from a number of industrial processes. The objective of this investigation was to compare the efficiency of advanced oxidation methods with that of O3 and UV radiation in Phenol degradation. For this purpose, a reaction chamber with a capacity of 3 liters (laboratory scale) was used. A photolytic cell system with a 125W UV lamp was designed and manufactured. The ozone used in the reaction was produced at a rate of 1g/h in a COG-OM ozonizer before entering the reactor. A set of experiments was carried out at pH levels of 5, 7, 9, and 11 to investigate the effect of pH on phenol degradation rate. Samples were then collected for analysis by a spectrophotometer. Our findings show that phenol is degradable at a basic pH of 11 with ozone application and at an acidic pH of 5 with UV radiation. Using a 125 WUV- light source, phenol degradation after one hour was 32.4% while it reached 93.6% after the same period when using ozone. Due to their desirable health and environmental impacts as well as their high efficiency, advanced oxidation processes are expected to be a promising technology for the removal of phenol and other similar pollutants from water and wastewater.

Adsorption process by activated carbon is widely used for removal of dyes. Because of economical limits, activated carbon derived from low cost materials seem to be economical. The aim of this work is preparation of activated carbon from poplar wood and investigation of its ability to removal of (AR18) dye. In this work, we prepared the activated carbon by chemical activation method in electric furnace. In addition we have investigated effect of various parameters such as pH, contact time, dye concentration and adsorbent dosage on dye removal. Langmuir and Freundlich isotherm models have been investigated. Pseudo-first order, pseudo-second order and modified pseudo-first order kinetic models have been used for experimental data. The results showed that removal efficiency was increased with increasing of adsorbent dosage, contact time and decreasing of pH, but with increasing of dye concentration, the removal efficiency was decreased. Adsorption isotherm models showed that Langmuir isotherm model was best fitted onto collected data (r2>0.978). In addition, kinetic models showed that sorption of AR18 onto activated carbon prepared from poplar wood follows the pseudo-first order model (r2>0.9758).

Since the process of heterogeneous Fenton is more complex and dynamic than the common Fenton process, control and online monitoring is entirely vital for optimum operation of this system. This study was aimed to investigate the effects of pH, oxidation-reduction potential (ORP) and dissolved oxygen (DO) variations on dimethyl phthalate (DMP) removal from aqueous solutions using the heterogeneous Fenton process with nano zero-valent iron (nZVI). Parameters affecting the process like contact time (5 - 120 minutes), pH (2 - 10), H2O2 concentration (0.01 - 1 mmol/L) nZVI content (0.01 - 0.5 g/L) and initial DMP concentration (2 - 50 mg/L) were also studied. It was found that, at optimum amounts (pH = 4, H2O2 concentration = 0.1 mmol/L, nZVI = 0.05 g/L, initial DMP concentration = 2 mg/L, and contact time = 60 minutes), approximately 98% of the pollutant was removed. This process could treat DMP well from aqueous environments and can be introduced as a cheap and effective method.

Disposal of chemical and toxic pollutants via industrial wastewaters into the environment has always been a hazard to water resources. According to scientific reports, biological systems are the most suitable method for treatment of such wastewaters. Obviously various effective organisms depend on the type of pollutants, treatment plant system and environmental conditions. Identification of the most effective microorganism is necessary for determination of optimum conditions, method of control and monitoring of bioreactor to access the maximum efficiency and improvement of operation. The objective of this study was to identify phenol degrader aerobe bacteria in combined biological phenol-treatment system of biofilter and activated sludge. Some amount of biological sludge was provided from domestic wastewater treatment as a primary source of microbe and was added to the designed reactor. Then samples were collected after growth of microbial mass. Phenol concentration and environmental condition (i.e. dissolved oxygen and pH) were stabilized after gradually adaptation of the system to phenol All samples were collected by sterile glass container. These samples were cultured on enrichment media and identified by various differential tests. dentification results proved phenol degrader bacteria are aerobe, nonfrementer but had negative result for of test with glucose as substra. These isolated bacteria were Pseudomonas aerginosa, P.alcaligenes, Moraxella sp, Acinetobacter sp, and Brevundiomonas vesicularis Because phenol was the only substrate and nitrogen and phosphorus as necessary factor in this system, all biodegrader bacteria used only Phenol as their both carbon and energy source. Phenol is degraded in a completely aerobic condition and dissolved oxygen concentration is sufficient since all the bacteria are aerobes.

The presence of antibiotics in the environment, especially aquatic environments, is a major health and environmental concern.Wastewater treatment plants play an important role in the treatment of municipal and industrial wastewater and removal of contaminants.The aim of this study was to determine the concentration of prevalent antibiotics in municipal wastewater of Hamadan,Iran and to evaluate the removal efficiency of wastewater treatment plants. During 3 months (April, May, and June 2016), a total of 12 composite influent and effluent samples were collected from the wastewater treatment plants. Solid-phase extraction (SPE) was used for preparing the samples, which were then analyzed using high-performance liquid chromatography (HPLC) with UV detection.Based on the analysis of 6 antibiotics, three antibiotics, including amoxicillin, imipenem, and cefixime, were detected, and their concentrations were measured at 1.6, 10.7, and 5.8 ug/L, respectively. The removal efficiency of these antibiotics in wastewater treatment plants was 55.66%, 34.01%, and 24.33%, respectively. Due to the presence of examined antibiotics in the effluent and influent wastewater treatment plants, they might cause direct and indirect effects on human health and environment if proper measures are not taken by the authorities. Since the removal of these antibiotics from wastewater treatment plants is relatively poor, it is suggested to use advanced wastewater treatment plants to reduce antibiotics in effluent wastewater and decrease the adverse effects of these micropollutants.