Search

This study investigates microbial community structures in landfill soils, focusing on fungal and bacterial compositions in aged (closed), active (operating), and leachate leakage zones, compared to a pristine zone. Molecular approaches revealed that bacterial phyla were most abundant in active landfill soil, particularly Actinobacteria (0.63-fold), Firmicutes (0.17-fold), and α-Proteobacteria (0.13-fold), while Nitrospira, Acidobacteria, and Chloroflexi were minimal. The results indicate a correlation between bacterial groups and landfill zone age. Additionally, the type of buried waste, including medical and municipal solid waste, significantly affected fungal diversity and abundance in surface soil layers.

In this experimental study, the performance of a fixed bed column containing a mixture of iron and aluminum modified with acid, as a reaction bed, was evaluated for the removal of heavy metals of cadmium, nickel, and copper. The tests were carried out by feeding the columns with aqueous solutions at the concentration of 100 mg/L using four iron/aluminum granular mixtures at various volume ratios (100/0, 50/50, 75/25, 25/75 and 0/100), and pH (3, 5, 7) for a total of 28 column tests. Results showed that metal ion removal was mainly accomplished via redox reactions that initiated the precipitation of mineral phases. At pH 5 and flow rate of 1 mL/min, the removal efficiency of cadmium, nickel, and copper at the 50/50 ratio of modified iron and aluminum was obtained higher than 99% and this removal efficiency could be kept about 50 hours. It seems that the column with the volume ratio of 75/25 of iron and aluminum mixture was the most efficient column for removing the heavy metals with the most suitable iron content and also high hydraulic performance due to the suitable aluminum content. It is therefore seen that the mixture of iron and aluminum can be used as an environmentally and economically viable remediation technology for the subsequent prevention of groundwater contamination.

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

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.

Background and purpose: Fluoride is one of the common anion in water that its concentration varies in different water supplies. Most of the body's requirement for fluoride is supplied through drinking water. Fluoride in low concentration is essential for human health but in high concentration is very hazardous for human health. The efficiency of modified-clay and lime-marl were investigated in this research as an adsorbent for the elimination of fluoride from aqueou solution. Methods: In this study, the capability of modified-clay and lime-marl to adsorb fluoride ions was conducted using a series of batch tests in a shaker-incubator instrument. The effect of experimental parameters such as pH (4,7,10), adsorbent dosage (1,5,10 g/L), initial fluoride concentration (5,10,15 mg/L) andcontact time (15-120 min) were evaluated. The morphological and micro-structural character of modified-clay and lime-marl have performed by using X-ray diffraction (XRD). The formation of the carboxylic functional groups was verified by Fourier transform infrared spectra (FT-IR). Findings: results well demonstrate higher removal efficiency of fluoride was 95.23% and 28.71 by clay-modified and lime-marl, respectively; at 10 mg/L of fluoride concentration and 60 min contact time. The adsorption kinetics fitted well using the pseudo second-order kinetic model; however, equlibrium data were best fitted onto Langmiur isotherm model. The maximum adsorption capacities of modified-clay and lime-marl for fluoride were found to be 4.43 mg/g and 1.32 mg/g, respectively. Conclusion: According to our finding, it proposed that adsorption process by using modified clay is very efficient and economic process for fluoride removal from aqueous solution.

In this study, degradation of p-chlorophenol (p-CP) was evaluated using persulfate (PS) activated zerovalent iron (ZVI) based ultraviolet (UV) in a bench scale photoreactor. The effect of operational parameters such as solution pH (3, 7, and 11), reaction time (0-60 minutes), ZVI dosage (0.15, 1.25, 0.5, 1, and 1.5 mM), PS concentration (0.5, 1.5, 2, 2.5, 3, and 4 mM), and initial p-CP concentration (0.22, 0.44, 0.88, 1.32, and 1.76 mM) were examined on the degradation of p-CP in batch experiments. The experimental results indicated that the p-CP removal rate significantly depends on operational parameters. The highest p-CP removal rate was achieved after 45 minutes (> 0.99%) in pH = 3, ZVI = 1 mM, and PS = 3 mM, and with initial p-CP concentration = 0.44 mM. The results revealed that excess amount of PS and ZVI could reversely affect p-CP removal efficiency. In addition, an increase in p-CP initial concentration from 0.22 to 1.76 mM significantly decreased its removal rate. This study indicated that PS activated ZVI based UV process is practically feasible for the effective degradation of p-CP in aqueous solution.

Introduction: Poly ethylene terephthalate (PET) is one of the major plastic compounds which are used to make different productions such as fibers and food containers. Due to the stability of the plastic in the nature, as well as reuse ability of some plastic wastes, codification of an integrated program to collect and recycle these materials is necessary. Methods: In this cross-sectional study, being done in four areas covered by Hamadan municipality, data was drawn from the range of journals, authentic internet sites, prepared questioners and direct interviews with solid waste manager and recycling organization director of Hamadan municipality. In order to estimate the amount of plastic waste, the total amount of wastes collected by public, private and itinerant sectors were evaluated. Then, the average rate of recycled PET was calculated per month. Results: According to results, 17.6% of city waste matters in Hamadan was in form of solid wastes, which PET’s contribution was 0.99%. By recycling process, also, it is possible to save 3160000 MJ energy and 56100$ from 51 tonnes of plastic waste. Conclusion: The result of this study showed that household recycling approach is more effective than other waste collecting management methods. In line with this, training people can play an essential role in learning recycling approaches.

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.

Background: Survey of pollution and evaluation of water quality in rivers with Oregon Water Quality Index (OWQI) and GIS are effective tools for management of the impact of environmental water resources. The information in calculating the WQI of Moradbeikriver allowed us to take our tests results and make a scientific conclusion about the quality of water. GIS can be a powerful tool for developing solutions for water resources problems for assessing water quality, determining water availability, preventing flooding, understanding the natural environment, and managing water resources on a local or regional scale. Methods: The WQI of Moradbeikriver consists of nine tests: Fecal Coliform (FC), Biochemical Oxygen Demand (BOD5), Nitrates (NO3), Total Phosphate (PO4), pH, temperature, Dissolved Oxygen (DO), turbidity, and Total Solid (TS). Water quality of Moradbeikriver was investigated for 12 months. Concentrations of these nine variables were normalized on a scale from 0 to 100 and translated into statements of water quality (excellent, good, regular, fair, and poor). Also this data were analyzed with WQI index, and then river basis on water quality was zoning by GIS. Results: The average of WQI was 61.62, which corresponded to ‘‘medium’’ quality water at the sampling point 1 (best station) and decreased to around 26.41 (bad quality) at sampling point 6. The association between sampling points and water quality indexes was statistically significant (P

Introduction & Objective: The use of computers and monitors (displays) has been developed due to their increasing capabilities. The presence of electromagnetic fields, infrared and ul-traviolet radiations has been proven around the display, which all of them have adverse ef-fects on human health. Therefore, this study was conducted to survey and compare the mentioned variables around the displays. Material & Methods: The present descriptive–analytical study was accomplished in Hamadan university of medical sciences in 2011. The statistical sample included 46 LCD and 50 CRT devices selected by simple random sampling. In order to assay the electric and magnetic fields, the HI-3604 device and for measuring the IR and UV rays, Hanger device was used. Results: The magnetic field in the CRT display was higher than the LCD display. Also the magnetic field of the front of the display was more than back position in the both displays (P=0.000). The electric field in the nearest distance of the display was higher in CRT than LCD (P=0.000). In 30 cm distances of CRT and LCD displays, 96% and 8.3% of the sam-ples had magnetic field more than TCO standard, respectively. Conclusions: The current finding demonstrated that LCD displays radiate much lower amount of magnetic field, IR and UV rays than CRT displays. Life extension of the system has a great influence on the production of electromagnetic fields.

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.

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.

Despite fossil fuels, the energy supply from biogas process is of renewable energy resources; this kind of energy can be generated in all parts of the world. Thus, the potential of anaerobic co-digestion for production of methane from wastes of an industrial slaughterhouse and fruit and vegetable center in the Hamadan city, west of Iran, was investigated. The digester was operated under the mesophilic (35 - 37°C) condition for a period of 40 days with 3 different C/N ratios (20/1, 30/1 and 40/1). Before operation of digester, the amounts of C and N in the wastes were measured and during the experiments pH and composition of the biogas were determined. The cumulative amounts of the generated total biogas and methane at the 3 examined C/N ratios 20/1, 30/1 and 40/1 were, respectively 181, 201.7 and 162.5 L and 129.8, 149.2 and 114 L. The results indicated that the highest contents of biogas and methane (201.68 and 149.29 L, respectively) were obtained at C/N of 30 within 31 days.

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.

Banking system plays an important role in boosting the economy and when they become profitable, they could help industries more efficiently. The proposed study of this paper attempts to investigate the effects of operating risk and capital structure on profitability of banking industry. The proposed study of this paper includes 17 commercial banks, which were active from 2006 to 2010 in Iran and the results of the study indicate that although there was a positive relationship between capital structure and profitability but there was no meaningful relationship between operating risk and capital structure. In addition, the results of our study mention that operating risks negatively impacts profitability and economic figures do not have any influence on profitability, operating risks and capital structure.

Organic and mineral compounds generated as products of waste mineralization within biological processes and accompanying physical and chemical processes are washed out by percolating rainwater through the deposit of wastes in landfill and form leachate that has created many health and environmental concerns.This study intended to determine the efficiency of reducing COD, BOD5, TS and color of Hamadan landfill leachate by using carbon nanotubes. Experiments were performed in batch reactor and changing effective factors such as pH, time and concentration of iron nanoparticles .The efficiency of carbon nanotubes were investigated using a statistical test, One-Way ANOVA software SPSS-12. Highest removal efficiency was at concentrations of 2500 mg/ L NZVI, pH = 2.5 and 10 minutes reaction time, 58.23%, 12.5%, 66.87% , 80% for COD, BOD, TS and color, respectively. The project results showed high potential for carbon nanotubes into absorbing organic use for treatment or pretreatment of Hamadan landfill leachate.

Introduction & Objective: Industrial wastewaters including heavy metals, are one of the important sources of environmental pollution. Heavy metals such as chromium is found in plating wastewater and is harmful for human health and environment. The purpose of the present study was to investigate adsorption of hexavalent chromium Cr (VI) from aqueous solution onto commerical Iron powder as an effective, faster ,and cheaper adsorbent. Materials & Methods: This research was an experimental- lablatory study done in batch system. This study investigated the removal of hexavalent chromium by using commerical Iron powder with variation pH, contact time, Iron powder dose and initial hexavalent chromium concentration in batch system , and the result was analyzed by Excel software. Results: The results showed that the removal efficiency decreased with increasing pH and initial chromium concentration. Also the results showed that the removal efficiency increased with increasing Iron powder dose and contact time. With increasing adsorbent dose from 0.1g/100cc to 1.5 g/100cc, the removal efficiency increased from 47.5% to 92.5 % in constant conditions (pH=7, initial hexavalent chromium concentration = 20 mg/L ). Also removal efficiency increased from 41.1% to 48.5% with increasing contact time from 2 min to 120 min in constant conditions (pH=7, Iron powder= 0.1g/100cc, initial hexavalent chromium concentration= 20 mg/L). Experimental isotherms and kinetics models were assessed by Langmuir and Freundlich isotherms and pseudo-first-order, pseudo-second-order kinetics and modifed pseudo-first-order models. The results showed that the data were acceptably explained by Langmuir isotherms and pseudo-second-order kinetics models, respectively. Conclusion: The results showed that the removal of hexavalent chromium from aqueous solution using sawdust can be done faster and cheaper.

Chromium is one of the heavy metals that is found in industrial effluents and is very toxic for human and environment. In this work the removal of hexavalent chromium by using of adsorption onto strongly basic anion was investigated. Various parameters such as pH, initial hexavalent chromium concentration, contact time and resin dosage were studied. Experimental data were expressed by Langmiur and Freundlich isotherm Pseudo-first order, Pseudo-second order and modified Pseudo-first order kinetic models. The results showed chromium removal was increased by increase of contact time and resin dosage, while decreased by increase of pH and initial hexavalent chromium concentration. At contact time equal 120 min, resin dosage 0.2 g/100 ml and initial hexavalent chromium concentration of 30 mg/l, by increasing pH from 3 to 11, removal efficiency was decreased from 93.56 % to 69.12 %. In addition, by increasing contact time from 5 min to 120 min, removal efficiency was increased from 39.51 % to 94.41 %. The results also showed hexavalent chromium sorption follows Langmiur isotherm model. Pseudo second order models best describe chromium removal by using of adsorption onto strongly basic anion resin. The results revealed that removal of hexavalent chromium from aqueous solution by using of adsorption onto stringly basic onion resins can be done quick and effective.

The aim of this study to synthesize nanoparticle zero valent iron and to determine its efficiency in arsenic removal from aqueous solutions. Nanoparticles were synthesized by reduction of ferric chloride using sodium borohydrid. The experiments were conducted in a batch system and the effects of pH, contact time, and the concentrations of arsenit, arsenat, and nano zero valent iron were investigated. SEM and XRD were applied for the determination of particle size and characterization of the nanoparticles synthesized. SEM results revealed that synthesized particles were of nano size (1-100 nanometers). At pH=7.0, 99% of arsenit and arsenat was removed when nano zero valent iron concentration was 1 (g L-1) over a retention time of 10 min. Based on the results obtained, the removal efficiency was enhanced with increasing nano zero valent iron dosage and reaction time, but decreased with increasing initial concentration and initial solution pH. The significant removal efficiency, high rate of process and short reaction time showed that iron nano particles are of a significant potential for the removal of arsenic from aqueous solutions.

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.

A vast variety of pesticides are used for agricultural pests in Iran. The release of these persistent organic pollutants. into water supplies leaves adverse effects on both the environment and public health. Advanced oxidation processes have been used recently for pesticide removal. In this research, the combined UV/O3 process has been investigated for the removal of organophosphorus pesticides (Diazinon, Chlorpyrifos), Carbamate pesticides (carbaryl). In this survey, samples have been prepared by adding given concentration (1, 5, 10, 15, 20 mg/L) of the pesticides to deionized water. The samples at separation periods were exposed to the combined UV/O3 (UV=50-200 Wm-2 and O3 = 1g hr-1)in a bath reactor at different pH levels (6, 7, 9) and for different contact times (0.5,1,1.5,2 hr) and the removal efficiencies were determined. Residual concentrations were determined using GC/MS/MS and HPLC. Based on the results, increasing pH reduced pesticide concentration and increased contact time had a direct effect on enhancing removal efficiency. The combined UV/O3 process was found to have a high efficiency (>80%) in degrading both halogenated Organophosphorus(Chlorpyrifos) and non- halogenated Organophosphorus (Diazinon) pesticides. Its removal efficiency for degrading carbamate pesticide (Carbari) was found to be >90%. Based on our results, this method may be suggested for the removal of pesticides from aqueous solutions.

Introduction: The raise of medical sciences graduates is counted to be on of the problems in public, as concern about the discipline and future career is evidently seen in students. This study was performed with the aim of determining environmental health students' attitude toward their discipline and future career carried out in Hamedan University of Medical Sciences in 2008. Methods: All environmental health students of Hamedan University of Medical Sciences studying morning courses of first semester of academic year 2008-2009 in associate, BS, and MS degrees were entered into this descriptive cross sectional study through census (n=115). The data gathering tool was Minnesota University questionnaire including 20 questions based on Likert scale. Data was analyzed by SPSS software using statistical t-test. Results: Mean and standard deviation of students' attitude toward their future career attained to be 56.6 and 11.2 respectively out of 96 questionnaires. Regarding the score of 60 as the mean score of the test, the attained mean score is lower than expected. Conclusion: The mean score for attitude of population under investigation toward their future career was lower than acceptable level which demonstrates lack of desirable attitude toward future career among students. It is while they have an acceptable attitude toward their discipline. Adjusting the number of students accepted, proper distribution of human resources, informing students about university disciplines before they take the entrance examination, and supporting the students financially may prove helpful in improving their attitudes.

Development of effective methods for the removal of such pollutants as heavy metals (e.g., mercury) from surface and ground water resources introduced by municipal and industrial wastewaters seems to be inevitable, especially in the face of the importance of water reuse in combating water shortages, limited availability of water resources, and imminent risks of a water crisis in Iran. A number of methods are already available for the removal of mercury from water resources. However, these techniques must be investigated for their practicability and economy, in addition to their not only effectiveness. In this research, granular activated carbon, natural zeolite, and anthracite packed-columns were investigated as cheap and effective adsorbents for the removal of mercury. Moreover, the effects of changes in pH (6-8), influent mercury concentrations (0.25, 0.5, 0.75, and 1 ppm), contact time (0.5, 1, 2, 3 hr) were investigated. Mercury concentration in the samples was determined using a ditizon indicator and spectrophotometry at 492 nm. Results showed that decreasing influent mercury concentration from 1 ppm to 0.25 ppm (under constant conditions) increased the removal efficiencies of anthracite, granular activated carbon, and zeolite columns from22%, 63%, and 55% to 28%, 72%, and 64%, respectively. Increasing contact time from 0.5 hr to 3 hr caused the removal efficiencies of these columns to increase from 22%, 56%, and 54% to 42%, 86%, and 82%, respectively. Also, increasing pH level led to increased removal efficiencies of the studied columns. It was found that contact time played a more effective role in enhancing mercury removal efficiency in the granular activated carbon column than in the other two columns. The ranges of mercury removal efficiency obtained for the granular activated carbon, natural zeolite, and anthracite columns under various conditions were (51%-92%), (42%-88%), and (16%-52%), respectively. Based on these results, granular activated carbon could be recommended as an effective and cheap adsorbent for the removal of mercury from drinking water resources.

Introduction & Objective: Rivers are one of the main water supply resources for various uses such as agricultural, industrial and drinking purposes. As population and consumption increase, monitoring of rivers water quality becomes an important function of environmental management field. Because Darreh-Morad Beyg river of Hamadan is a water supply for different purposes and many pollutants are discharged in it, its water quality assessment seems necessary. Zoning of pollution and depicting a detailed image of surface water resources quality using geographic information system (GIS) are the key factors for the better management of these resources. Materials & Methods: This research is a cross sectional- descriptive study and river water samples were taken for 7 months from 6 sampling stations on the length of the river. Biochemical oxygen demand (BOD), electrical conductivity, dissolved oxygen (D.O.), pH, fecal coli form, nitrate, temperature, phosphate and total solids were determined in the samples. Obtained data were analyzed by national sanitation foundation water quality index (NSFWQI) and the river was zoned using GIS software. Results: Results of the analyses by NSFWQI showed the best water quality for station 1 and the worst water quality for station 6 with scores of 62.78 and 27.49, respectively. Conclusion: The NSFWQI is a suitable index for zoning of Darreh-Morad Beyg river. Monitoring of physical, chemical, bacteriological quality parameters and using water quality index in various sampling stations are used in the assessment of water pollution. It also helps the officials to correctly decide about the water uses for different purposes.

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.

Pentachlorophenol (PCP), which is one of the resistant phenolic compounds, has been classified in the category of EPA’s priority pollutants due to its high toxicity and carcinogenic potential. Therefore, its removal from water and wastewater is very important. Various methods have been studied for removing the compound, among which advanced oxidation processes (AOPs) have attracted much attention because of ease of application and high efficiency. Thus the aim of this study was to investigate the efficiency of the UV/ZrO2/H2O2 process, as an AOP, for PCP removal from aquatic environments. The effects of several parameters such as ultraviolet (UV) exposure time, initial PCP concentration, pH, concentration of zirconium dioxide (ZrO2) nanoparticles, and H2O2 concentration were studied. Kinetics of the reaction was also detected. The concentration of the stated materials in the samples was determined using a spectrophotometer at 500 nm. The results showed that the highest efficiency (approximately 100%) was reached at optimized conditions of pH 6, contact time of 30 minutes, initial PCP concentration of 20 mg/L, the nanoparticles concentration of 0.1 g/L and H2O2 concentration of 14.7 mM/L. Also, the process followed the first order kinetics reaction. The obtained results illustrated that the UV/ZrO2/H2O2 process has a high ability in removing PCP.

چكيده زمينه و هدف: زائدات جامد کشتارگاهی، حاوی زائدات روده‌ای دام و جامدات آلی دیگر می‌باشد که فسادپذیر بوده و دارای مقادیر بالای میکروارگانیزم‌های پاتوژن می‌باشد. از این رو برای اجتناب از انتشار عوامل عفونت‌زا، مدیریت زائدات مذکور ضرورت دارد. هدف از مطالعه حاضر تولید کود کمپوست با استفاده از زائدات کشتارگاه صنعتی همدان به روش هوادهی ساکن و توأم با اختلاط می‌باشد. مواد و روش‌ها: در کلیه مراحل انجام تحقیق پارامترهای اساسی نظیر نسبت کربن به ازت، فسفر، پتاسیم، pH، هدایت الکتریکی(EC)، درصد خاکستر و درصد مواد آلی فرار اندازه گیری شد. يافته‌ها: در روش هوادهی ساکن، نسبت کربن به ازت معادل 59/15، فسفر برابر 16/3 درصد وزنی، پتاسیم برابر 16/2 درصد وزنی، pH برابر 08/7، EC برابر μS/cm 1586 و خاکستر معادل 88/16 درصد وزنی بود. همچنین در روش هوادهی توأم با اختلاط، نسبت کربن به ازت معادل 68/18، فسفر برابر 02/3 درصد وزنی، پتاسیم برابر 35/2 درصد وزنی، pH برابر 2/7، EC برابر μS/cm 1423و خاکستر معادل 78/20 درصد وزنی حاصل شد. نتيجه گيري: بنابراین هر دو روش کمپوست هوازی ساکن و هوازی توأم با اختلاط سبب تثبیت زائدات جامد کشتارگاه و تولید کود کمپوست شدند. کود تولیدی از هر دو روش از کیفیت رضایت بخشی برخوردار بود.

In recent decades, increasing pollution of water resources has caused higher rates of organic pollutants in water resources. Considering the surface water resources as one of the main water supplies in many regions of Iran and the application of chlorination for disinfecting drinking water has increased the rate of Disinfection By- Products (DBPs) formation. Trihalomethanes (THMs) as the main group of DBPs are categorized and considered to have the potentiality of increasing the rate of liver , kidney and CNS adverse effects. Air stripping and membrane technology can be used for the removal of THMs. In this research , two pilots were designed and set up : Air stripping packed – column and Nanofilter(NF)spiral-wound modules. The effects of changes in flow rate and chloroform concentrations were investigated in both treatment systems and the transmemberane pressure for membrane pilot as the basic variables affecting removal efficiencies. Gas Chromatography(GC) with Electron Capture Detector(ECD) was used for determination of chloroform concentration in water samples. The obtained data were analyzed by SPSS and non-parametric Kruskal–Wallis .The results showed a positive correlation between the flow rate and chloroform concentration, and removal efficiencies. In this study, chloroform removal efficiencies for air stripping pack-column were higher than NF 300 , and 600 Da. Variation range of removal efficiencies for air stripping column , NF 300 Da and 600 Da with deionized water samples has been 82.3% to 97.6 %, 60.5% to 87.2% and 42.3% to 67.6 % , respectively.

Although municipal solid waste (MSW) is generated every day , but with comparison to other municipal Environmental aspects such as Air pollution and Sewage, is not well considered. MSW management includes refuse production, storage, collection, transportation and disposal. Without adequate and reliable in formation and data about MSW generation rate and it’s physical components, optimun planning and management is not obtainable. In this research the physical composition of Hamadan MSW was studied . Samples were takan by Truck–Load sampling and portional random method from June 1999 untile May 2000 and analyzed for physical components and moisture percent age. The results showed that the average generation rate, density of wastes and its moisture percent were 252.33 Tons and 204.83 kg/m3 and 22.46% respectively. Average percents of physical componets were 77.72% , 5.75% , 5.42% , 3.15%, 2.11% , 1.04% and 4.92% for Biodegriable materials (garbage), papers, plastics, textiles, metals, glass and other materials respectively. Also maximum generation rate was 328 tons in March and minimum generation rate was 196 tons in December. In general, with planning of enforceable reuse and recycling programmes, could be avoid of 183, 14, 13 and 5 tons of biodegriable materials , paper, plastics and metals burial respectively everyday.

Surfactants are one of the main groups of pollutants released into aqueous solutions due to human activities and their harmful effects have been proven on human. In this study, first, magnetic multi-walled carbon nanotubes (MMWCNTs) were synthesized and then, the effects of operating parameters such as surfactant concentration, adsorbent dosage, and pH values were analyzed on the adsorption process. MMWCNTs were characterized by means of X-ray diffraction (XRD) analysis and fourier transform infrared spectroscopy (FTIR). The optimal adsorption conditions were achieved at initial pH = 4.6, adsorbent concentration = 0.5 g/L, and initial SDS concentration = 15 mg/L. In addition, the equilibrium of sorption reached after 120 min and the maximum capacity of SDS for monolayer coverage was found to be 61 mg/g at 25°C. Kinetic studies were performed under optimal conditions and the sorption kinetics was described using the pseudo-second-order kinetic model. The experimental data were studied using Freundlich, Langmuir, and Sips models. Finally, the experimental data were fitted reasonably by Langmuir isotherm. The results demonstrated that MMWCNTs with respect to their high adsorption capacity, relatively low equilibrium time, and capability to be separated from aqueous solutions (after adsorption) could be applied to wastewater treatment.

In this study, ZnO Nano catalyst has been synthesized and examined as photo catalyst for UV-induced removal of Sodium Dodecyl Sulfate (SDS) from aquatic solutions. This anionic surfactant was selected based upon its toxicity, wide use in industrial laundry and as a primary pollutant in municipal waste water systems.This study aimed to investigate removal of surfactant, SDS, in a batch photo catalytic reactor under various operating conditions including ZnO suspension concentration, initial surfactant concentration and initial pH of solution to find out the desired condition for removal of surfactant. ZnO Nano crystals were synthesized using the precipitation method and ZnSO4.7H2O was used as the starting material and NaOH as precipitant. The removal of SDS reactions by UV/ZnO process was performed into a batch photo reactor. In addition, various operating conditions including ZnO suspension concentration, initial surfactant concentration and initial pH of solution were investigated. In total, 98% of surfactant was removed at 40 minute and removal efficiency of SDS increased with increasing pH up to nine and after that with increase in pH, efficiency decreased. Possible roles of inorganic oxidant on the reaction were discussed. The removal of SDS follows pseudo-first order kinetics. Based on the results of this study, ZnO-UV photo catalytic process can be used as an efficient method for further study in detergents removal.

To determine the distribution of lead in ambient air of Hamadan, 100 samples were taken in different places from December 1997 until June 1998. The places of samples collection , were divided to three locations in street (high traffic, medium traffic and low traffic), gas pump stations and parking of cars. Portable sampling pump and filter cellulose were used to obtain samples. The samples transferred to laboratory and analyzed with atomic absorption spectrophtometry. The results showed the concentration of lead was 1mg/m3 in low traffic and 18 mg/m3 in high traffic places. The average concentration of lead in high traffic, medium traffic and low traffic were 7.99 , 4.63, 3.80 mg/m3 respectively and have significant difference among concentration of lead in low traffic places with gas stations and parking of cars. The average concentrations of lead in ambient air of Hamadan was more than the standard limit (1.5 mg/m3 ) in ambient air recommended by World Health Organization (WHO), and United States Environment Protection Agency (USEPA).