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At present, the distribution of antibiotics in wastewater is mainly concentrated in municipal sewage treatment plants, and little attention is paid to the distribution and removal of antibiotics in...

This research aimed the performance evaluation of a structured bed reactor with different cycles of Intermittent Aeration (IA)(SBRRIA) in the municipal sewage treatment and the verification of the effect of IA cycles on the total nitrogen (TN) removal and organic matter (COD). Three IA cycles were evaluated: phase I (4 h AE (aeration on) - 2 h NA (aeration off)); II (2 h AE-1 h NA) and III (2 h AE-2 h NA), with Hydraulic Retention Time of 16 h. The best nitrogen removal was obtained during phase II, with the lowest non-aeration time: efficiency of nitrification, denitrification, TN and COD removal of 80 ± 15%, 82 ± 12%, 67 ± 6% and 94 ± 7%, respectively. The mean cell residence time was 19, 26 and 33 d in phases I, II and III, respectively. The statistical analysis applied to the AE/NA profiles showed that the time of AE and NA in the cycles did not influence nitrogen and organic matter removal. Thus, this indicates the recirculation and the gradient formed in the support material facilitate the process of Simultaneous Nitrification and Denitrification. The lowest concentration of nitrifying and denitrifying microorganisms was obtained in effluent and sludge at the end of phase III. From the TP (Total Proteins)/TPS (Total Polysaccharides) ratio obtained (0.8 ± 0.1, 1.3 ± 0.1 e 1.5 ± 0.1 in phases I, II and III), it was possible to conclude that the biofilm in phase I was more porous, with a thin layer if compared to that in phase II and III.

As a by-product of municipal sewage treatment, sewage sludge must be properly treated to avoid secondary pollution to the environment. Aerobic composting is one of the mainstream technologies in sl...

Phytoremediation techniques and stabilization of heavy metals with municipal sewage sludge (SW) in soils are usually studied separately. We aimed to verify the potential of the combined use of phytoextraction method and metal stabilization with SW in the recovery of soil with high Pb content (total = 28,650 mg kg

Discharge of untreated waste water, municipal sewage, industrial effluents, dumping of degradable and non-degradable wastes has polluted natural water sources like river, lake, pond to a great exte...

Anticancer drugs used in cancer treatment are excreted unchanged or as metabolites by feces and urine in hospitals and households. These drugs enter the municipal sewage system but wastewater treat...

The anaerobic co-digestion of fruit and vegetable waste (FVW) and municipal sewage sludge (MSS) is investigated under mesophilic conditions. This was done at a constant hydraulic retention time (HRT) similar to that typically used at waste water treatment plant digesters, 20 days. The effects on digester performance of the FVW:MSS ratio and the organic loading rate (OLR) were examined. Initially the digester was fed with MSS from wastewater treatment plants (WWTP) with an average OLR of 1.03 kg

Anaerobic treatment of dilute wastewater (e.g., municipal sewage) is promising due to energy recovery and lessened operating costs, both of which can significantly improve the sustainability of was...

The present research was done to study the ability of cyanobacterial species for removing heavy metals from sewage. As well, to estimate the growth and some metabolites of Beta vulgaris irrigated w...

In this work, the effects of diatomite with 15% FeSO4•7H2O and 7.5% Ca(OH)2 on sludge stabilization were investigated using batch leaching tests. The influence of cell rupture caused by freezing and thawing on stabilization was also evaluated. The results indicated that the optimal diatomite percentage was 2%. Cell rupture by freezing and thawing reduced heavy metal leachability, followed by cell death and decrease of organic groups. The concentration of heavy metals in sludge leachate increased after cell rupture, indicating that the heavy metal leachability was reduced after freezing and thawings. Moreover, the stabilization effects were generally improved after freezing and thawing. As compared with the stabilization of the original sludge, the unstable fractions decreased and the residual fractions of the heavy metals increased in the stabilized sludge after cell rupture.Implications: This study developed a method to stabilize heavy metals in municipal sewage sludge. Diatomite combined with Fe...

Biogas is produced by anaerobic (oxygen free) digestion of organic materials such as sewage sludge, animal waste, and municipal solid wastes (MSW). As sustainable clean energy carrier biogas is an ...

Over 30 million tons of excess sludge is discharged from rural municipal sewage plants annually in China and it is predicted that this figure will keep increasing. However, most of the excess sludge is dumped in landfills except for minor applications. In this study, based on low-cost and recycling waste, the excess sludge was used to adsorb organic dyes from aqueous solution after being directly dewatered. The powdered excess sludge (PES) presents selective adsorption property to cationic dyes. Statics batch adsorption experiments of malachite green (MG) on PES were performed to evaluate the effects of pH, adsorbent dosage, and initial MG concentration. Results revealed that the bio-adsorption equilibrium of MG on the PES can be quickly achieved at 30 min with maximum percentage adsorption of 84% at pH 7, initial dye concentration of 20 mg L−1, and adsorbent dosage of 1.5 g L−1. Moreover, the adsorption kinetics follows a pseudo-second-order pathway, and the equilibrium adsorption data could be d...

To date, remarkable progress has been achieved in the fabrication of poly(vinylidene fluoride) (PVDF) membranes with high performance for applications in wastewater treatment. After a comprehensive overview of recent progress on the preparation of PVDF membranes via thermally induced phase separation (TIPS) method, this paper provided historical information about the plenty of work focused on the preparation and advanced industrialization of PVDF membranes that was carried out by Beijing Key Laboratory of Membrane Materials and Engineering of Tsinghua University (Beijing, China). The work followed the line of formula design, advanced production, and membrane module development. Firstly, an innovative PVDF membrane with good performance was prepared via TIPS (liquid–liquid, L–L) method based on exhaustive thermodynamic and dynamic researches on the membrane formation process. Secondly, advanced production of the PVDF hollow fiber membrane was achieved by an effective combination of material process...

This work was devoted to investigating the long-term cumulative effect of municipal sewage treatment plant (STP) effluents on the sediments, near the plant outlet, in Yunliang River in Nanjing, China. Laboratory experiments were performed to assess the effect of different aeration modes on the migration and distribution of phosphorus (P) in the sediments. The field investigation showed that the concentrations of organic matter, different P fractions, dehydrogenase activity and alkaline phosphatase activity in sediments near the STP outlet were higher than those in the upstream site. The results of laboratory studies documented that the retention of P in sediments mainly depended on the characteristics of sediments. Collectively, long-term intermittent aeration accelerated the conversion of parts of organic phosphorus to occluded Fe–P due to that Fe2+ were oxidized to Fe3+ gradually, inactivating the sediments P, which preventing P release completely even in the case of anoxic conditions. Compared ...

To assess the impact of sewage water on metal accretion in selected diverse varieties of wheat (i.e., Lasani-2008, ARRI-10, Faisalabad-83, Punjab-85, Aas-2010, and Sehar-2006), their seeds were sown in pots containing soil. The results showed that the concentration of heavy metals in grains from the wheat plants supplied with sewage water was considerably higher than the plants supplied with canal irrigation water (control). In canal water irrigated wheat grains the metal concentrations (mg/kg) ranged from 2.20–3.5 for Cu, 12.50–32.4 for Zn, 22.45–35.22 for Mn, 0.05–0.15 for Pb, 0.012–0.029 for Cd, 2.5–5.3 for Ni, 18.16–29.63 for Fe, and 0.90–3.64 for Cr in different wheat varieties, whereas the wheat grains raised from sewage water, had metal concentrations (mg/kg): 3.8–5.30 for Cu, 29.60–40.50 for Zn, 32.9–50.40 for Mn, 1.14–7.50 for Pb, 0.26–0.42 for Cd, 3.90–7.55 for Ni, 32.21–40.35 for Fe, and 2.88–7.84 for Cr. Since these metals bioaccumulate in wheat grains with unremitting use of metal-enr...

The aim of the studies was to indicate whether the insecticides have toxic impact on the course of the process of sewage sludge methane fermentation and their biochemical durability is. The researc...

International audience; A model based on the theory of Markov chains has been developed to represent the residence time distribution (RTD) of municipal sewage sludge in a continuous paddle dryer. The flow of dry solids is described by a chain of n perfectly mixed cells, n corresponding to the number of paddles attached to the shaft. The transition probabilities between the cells are governed by two parameters: the parameter of internal recirculation, R, and the solids hold-up, Hu. In the absence of available correlation, both parameters are identified by fitting the model to experimental RTD data. The model demonstrates its ability to describe the sludge flow in a continuous lab-scale paddle dryer. A sensitivity analysis highlights that R is critical for the treatment uniformity while Hu controls the mean residence time and thus the final moisture content.

Numerous antibiotics such as sulfonamides have been found in effluents from drug manufacturers. Removal of pharmaceuticals by adsorption and ion exchange comprise some of the most promising techniques for the retention of these compounds from wastewaters due to their low cost, easy regeneration, and selective removal of pollutants. This article studies the removal of sulfamethoxazole (SMX) and sulfamethazine (SMZ), the most common sulfonamide antibiotics detected in municipal sewage. Lewatit MP500 (Lanxess Chemical) ion exchange resin was used to remove SMX, SMZ present in solutions. Batch experiments were carried out in cylindrical stirred tanks. Binary system solutions of equal mass concentration were prepared containing 30-250 mg/L of each compound, SMX and SMZ, and tested with an L/S ratio (mL solution/g resin) = 1000 obtained in previous experiments. Also, the adsorption of SMX mixed with trimethoprim (TMP) in batch experiments was analyzed due to the fact that both compounds are usually administered...

The present paper deals with the characterization of the municipal sewage sludge (MSS) and the effectiveness of the waste water treatment plant (WWTP) under warm climate condition. The WWTP effectiveness is more than 98.5% for the BOD5, 90% for COD, 95% for SS, 70% for TN, 99% for NH4, while the TP efficiency rang from 15.17% to 99.12%. The total kWh/kgBOD5/month is from 1.97 to 3.13, while the total kWh/m3 of wastewater influent range from 0.62 to 1.36. The yearly chemical consumption (chlorine, polymer, lime) depends at the end from the season. The sludge does not present significant concentration of metals and the evaluation with sequential extraction showed that the metals are associated with inert forms while the application of the, Generalized acid neutralization capacity (GANC) test indicated that by increasing the leach ate pH, the heavy metal concentration decreases.

Constructed wetlands with horizontal subsurface horizontal flow are commonly used for treatment of municipal sewage and are well monitored for removal of organics, suspended solids, nutrients and b...

Release of steroid estrogens such as estrone (E1), 17β-estradiol (E2), estriol (E3), and 17α-ethinylestradiol (EE2) into the urban environment is of concern due to their prominent endocrine disrupting properties. This review focuses on the fate of estrogens as well as estrogenic potentials in the sewerage system starting from human excretion to municipal sewage treatment facilities. To examine the roles of different components in the municipal sewage treatment facilities in the removal of estrogens, data from 130 full-scale municipal sewage treatment plants (STPs) in 14 countries were summarized. Primary treatment systems removed less than 10% of the influent estrogens. Municipal STPs with the secondary biological treatment systems gave higher percentage removals of estrogens and estrogenic potentials than municipal STPs without secondary biological treatment systems. On average, municipal STPs with suspended growth systems gave better percentage removals of estrogens and estrogenic potentials than attach...

This paper evaluates case-based design principles in the design of Soche wastewater treatment works (WWTW) in the city of Blantyre, Malawi. According to the Case Study Manager in the ED-WAVE tool, a similar case to both dry season and wet season conditions of Soche plant is Municipal Case 6 in Greece. The raw material at Municipal Case 6 in Greece is raw municipal sewage where the typical wastewater parameters are BOD5, and TSS. The treatment target is BOD5, and TSS reduction. The study confirmed the practical use of case-based design principles in the design of wastewater treatment systems, where after encountering a new situation; already collected decision scenarios (cases) are invoked and modified in order to arrive at a particular design alternative. What is necessary, however, is to appropriately modify the case arrived at through the Case Study Manager in order to come up with a design appropriate to the local situation taking into account technical, socio-economic and environmental aspects.

Pharmaceuticals and personal care products (PPCPs), including estrogen pharmaceuticals, have been an environmental concern for well more than a decade, but no environmental emissions inventory for Canada has yet been published. Endogenous estrogens cannot be distinguished from the equivalent pharmaceutical estrogens in the environment. Therefore, data were compiled to estimate total environmental emissions of endogenous and retail pharmaceutical estrogens by the Canadian population for year 2007. Approximately 1,700 kg of pharmaceutical estrogens were dispensed through retail pharmacies in Canada in 2007. Of this amount, total environmental emissions were estimated to be approximately 730 kg, half to surface water via municipal sewage outfalls (> 90% via sewage treatment plants providing primary, secondary, or tertiary treatment), and half to the soil vadose zone and (potentially) groundwater via in situ sewage treatment systems. Approximately 960 kg of endogenous estrogens were excreted by the C...

The article deals with the effects of different Cd concentrations (5 and 50 mg kg-1) in municipal sewage sludge compost on survival, activity and adaptation of Eisenia fetida californica earthworms. Investigations were carried out under laboratory conditions. Experiments were also conducted on adaptation of second-generation juveniles to Cd-contaminated sludge substrates. Dynamics of Cd concentrations in sludge, earthworm tissues and compost-grown lettuce was constantly monitored. Cd concentrations in earthworms were found to be 4.1 (5 mg Cd kg-1 variant) and 2.8 (50 mg Cd kg-1 variant) times higher than those present in sludge compost. Cd concentrations accumulated in earthworms had no direct impact on their survival and reproduction. On average, 2.7 and 3.3 juveniles per cocoon hatched in substrates with 5 and 50 mg Cd kg-1, respectively. Second-generation juveniles hatched in Cd-contaminated substrates successfully adapted to the given Cd concentrations.

This paper compares the USDA National Organic Program Final Rule with consumer preferences. Results of a survey administered to a group of current consumers of organic food indicate that most consumers prefer the stricter version of standards and will pay to avoid the “Big 3” (Genetically Modified Organisms, Municipal Sewage Sludge (a.k.a., Biosolids) and Irradiation) in organic food. Welfare impacts of the Rule are measured. Regression results suggest those most willing to pay to avoid the Big 3. Implications of these results for public policy and private firm strategy are discussed.

Androgenicity was tested in municipal effluents before and after treatment in sewage treatment plants using different treatment methods. The activity was tested with a recombinant yeast strain transfected with the gene for the human androgen receptor. Fractionation of effluents showed some basic properties of compounds with androgenic activity. Effluents from Swedish domestic sewage treatment plants contained compounds with androgenic effects. Levels varied from 0-160 ng dihydrotestosterone (DHT) equivalents/L. The androgenicity was higher in untreated effluents and removals of 26 and 42% for STWs without secondary treatment and 96-99% were recorded for STWs with secondary and tertiary treatment. As with estrogens in municipal effluents, STWs using biological treatment such as activated sludge and solid supported microbial processes were more effective in reduction of androgenic activity. Plants using only precipitation methods removed less of the activity. The androgens were composed of at least three individual compounds, similarly or less lipophilic than DHT.

The cost-effectiveness of rapid assessment approaches make their adaptation for use in developing countries appealing, but biological assessment methods need to be validated before use in new geographic areas. The authors tested the suitability of a family-level biotic index for use in a river in west-central Mexico that receives organic point-source pollution from untreated municipal sewage and sugar-cane processing. The biotic index was highly correlated to dissolved oxygen, and could detect different levels of pollution. Information from rapid assessment biomonitoring was used successfully by local natural resource managers to help bring about improvements in water resource management.

International audience; Whereas indirect agitated drying has been extensively studied for granular materials, little is known in the case of pasty products. We describe an experimental set up specially designed for the investigation of drying kinetics, of heat transfer coefficient evolution, and of the mechanical torque necessary for stirring. This device was applied to municipal sewage sludge. Preliminary experiments were performed to investigate the influence of ageing of sludge on the drying kinetics. It appears that ageing does have no effect except for the first two days. The influences of the wall temperature, the stirrer speed, the dryer load and the location of the stirrer against the heated wall were studied. Three different rheological behaviors were observed during sludge drying. In particular, the sludge goes through a ``glue'' phase, and high levels of mechanical strain are recorded when the compact mass begins to break up. A critical stirrer speed is found within the range 40-60 rpm. To shorten the drying time, it seems better to adjust the wall temperature in accordance with the moisture content of the sludge.

This study investigated medical waste practices used by hospitals in Oregon, Washington, and Idaho, which includes the majority of hospitals in the U.S. Environmental Protection Agency's (EPA) Region 10. During the fall of 1993, 225 hospitals were surveyed with a response rate of 72.5%. The results reported here focus on infectious waste segregation practices, medical waste treatment and disposal practices, and the operating status of hospital incinerators in these three states. Hospitals were provided a definition of medical waste in the survey, but were queried about how they define infectious waste. The results implied that there was no consensus about which agency or organization's definition of infectious waste should be used in their waste management programs. Confusion around the definition of infectious waste may also have contributed to the finding that almost half of the hospitals are not segregating infectious waste from other medical waste. The most frequently used practice of treating and disposing of medical waste was the use of private haulers that transport medical waste to treatment facilities (61.5%). The next most frequently reported techniques were pouring into municipal sewage (46.6%), depositing in landfills (41.6%), and autoclaving (32.3%). Other methods adopted by hospitals included Electro-Thermal-Deactivation (ETD), hydropulping, microwaving, and grinding before pouring into the municipal sewer. Hospitals were asked to identify all methods they used in the treatment and disposal of medical waste. Percentages, therefore, add up to greater than 100% because the majority chose more than one method. Hospitals in Oregon and Washington used microwaving and ETD methods to treat medical waste, while those in Idaho did not. No hospitals in any of the states reported using irradiation as a treatment technique. Most hospitals in Oregon and Washington no longer operate their incinerators due to more stringent regulations regarding air pollution emissions. Hospitals in Idaho, however, were still operating incinerators in the absence of state regulations specific to these types of facilities.

In 1993 there were an estimated 4000 employees working at 321 municipal composting facilities in 46 states. This work force may be exposed to dusts of biological origin, various gases, and airborne heavy metals. This study was designed to quantify contaminant concentrations at the Longmont, Colorado, composting facility. Sampling was divided into two phases. Phase I took place from June 12 through June 16, which was the facility's time period for peak volume. Phase II occurred from August 14 through August 18. Total dust concentrations as high as 173.79 mg/m3 were measured. The geometric means of total dust samples on days with screening and sweeping operations were 23.05 and 35.19 mg/m3. The mass median aerodynamic diameter (MMAD) of the aerosol was approximately 4.0 μm. The high dust concentrations coupled with the small MMAD indicate a possible occupational health risk from dust exposure at this municipal composting facility. Endotoxin concentrations varied from 28.9 to 5930.6 ng/m3. Using reg...

▪ This report originally appeared in the March/April, 1979 issue of Compost Science/Land Utilization, the precursor publication to both Compost Science & Utilization and BioCycle. At the time, the author, a Sanitary Engineer, was working with the City of Bangor, Maine to site a permanent municipal sewage sludge composting facility. “Factions opposed to the proposed facilities claimed that the airborne [A. fumigatus] spores would pose a severe hazard to the health of nearby residents,” writes Olver. “Because of the applicability of these contentions to the selection process for a new site, an extensive study of the available literature on the subject was conducted at the Bangor project during the summer of 1978.” The resulting research — summarized here — covers optimum habitat and physical characteristics, the occurrence of A. fumigatus in the sludge composting environment and in nature, and the fungi's pathogenic characteristics. Sixteen years later, the topical nature of the information in this report p...

The purpose of this article will be to provide a critical review of the factors involved in using municipal sewage sludge to reclaim strip mined lands. This literature review will include discussions of federal and state regulations, project planning and development, site characteristics, selection and preparation, sludge types and characteristics, sludge processing and transportation, sludge application methods and rates, vegetation establishment and management, monitoring systems, and environmental safeguards. Some design examples will also be given.

Oats were cultured on soil amended with municipal sewage sludge from Syracuse, N.Y., or on soil alone (control). The oats were fed to male and female Japanese quail through four generations. The extent of absorption of cadmium by the oats and its deposition in tissues and eggs of the first and fourth generations of birds were determined. The tissue levels of cadmium found in the first (F0) generation were kidney greater than liver greater than muscle approximately equal to eggs, with the quail from the sludge-treatment group consistently showing the higher respective tissue levels. Female birds showed consistently higher tissue levels than those of the corresponding males. Kidney and liver tissues and eggs from the fourth generation (F3) quail fed the sludge-treatment diets were also higher than the corresponding controls, but tissues of the male quail were most often higher than the corresponding females.

Adsorption of Cu(II) on activated sludge from the treatment of municipal sewage is studied. The resulting adsorption isotherm is of the Langmuir type.

The nonionic macroreticular resin XAD‐2 efficiently recovers many volatile organic compounds from distilled water. Changing from distilled water to sewage as the extraction matrix reduced recoveries of chlorinated phenols by approximately 20 percent primarily as a result of the phenols being adsorbed by filterable particulates in the sewage. The breakthrough of sewage occurs at about 130 column volumes and is pH dependent. The capacity of the resin is 1.7 mg TOC/cc of resin and independent of pH. The resin recovers about 30 percent of the TOC in sewage. Most of the organic material extracted by the resin is non‐volatile as far as GC analysis is concerned.

The levels of 20 elements (Al, Ca, Cd, Cl, Co, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, Sb, Se, V, and Zn) are reported for kidney, liver, muscle, spleen, and brain tissues taken from two groups of six steers per group in a feeding study conducted at Colorado State University. The control group was fed a normal feedlot cattle ration and the test group was fed the same ration amended with 12% (by weight) air-dried municipal sewage sludge. Elemental levels are also reported for the control and test diets, control and test feces, and sewage sludge added to the diet. All samples were analyzed by inductively coupled plasma emission spectroscopy and neutron activation analysis. Brief descriptions of the analytical methods are included. The levels of all metals determined were elevated in the test diet (as much as 19-fold for Cd) compared with the control diet. The levels of Pb and Cd in kidney and of Pb, Cd, and Cu in liver in the test animals were high enough to cause concern from a toxicological standpoint if these tissues were consumed regularly by humans. None of the levels of any of the other elements in the control and test animal tissues were high enough to cause similar concern with respect to human consumption.

The operational costs of pre‐ and simultaneous precipitation for the removal of phosphates from municipal sewage are calculated on the basis of two precipitant prices as a function of the amount of sewage per capita and compared with real costs that are indicated. The relationship of costs and specific amount of sewage provides an explanation of the differences in the costs that are indicated. The operating expenses of precipitation can be lowered by a controlled dosage of the precipitant. The best results are obtained when the actual value of the phosphate load is formed and used for the control of the process. In this way about a quarter of the costs can be saved.

A mixture of undigested sludge cake with ground rice hulls as a bulking material was composted, and the changes in various properties of the mixture during active composting and curing were studied using a newly devised experimental apparatus for composting. The essential results obtained were as follows. 1. The temperature of the mixture was rapidly raised to 60°C by active composting and this level was maintained for more than 10 hr. 2. The concentration of gaseous NH3 and CO2 in the off-gases increased soon after initiation of the active composting and decreased to a low constant level on the 14th day, when the active composting was judged to be finished. 3. The BOD3 sharply decreased until the end of the active composting and maintained a low constant level thereafter. 4. The ignition loss gradually decreased during curing. These changes were found to be useful as indices for checking the process of composting.

Anaerobic treatment is being applied successfully to low strength wastes like domestic sewage. UASB and AFBR reactors have been most often used. Two laboratory scale reactors were used to study the performance of these two systems operating in similar conditions for long periods of time (320 days). Both reactors were fed with domestic sewage (CODt=500 mg.L‐1, BODs=325 mg.L‐1 and TSS=190 mg.L‐1) at room temperature, 20°C. Better removal of CODt, BODs and TSS were achieved with AFBR. The restarting was shorter and easier for the AFBR.