Showing papers on "Effluent published in 2001"

Analysis of estrogenic hormones in municipal wastewater effluent and surface water using enzyme-linked immunosorbent assay and gas chromatography/tandem mass spectrometry

Abstract: Although the estrogenic hormones 17 b-estradiol and 17a-ethinyl estradiol can be quantified in polluted waters by gas chromatography/mass spectrometry (GC/MS) and gas chromatography/tandem mass spectrometry (GC/MS/MS), the compounds often are present at concentrations below detection limits. Enzyme-linked immunosorbent assays (ELISAs) provide a sensitive and robust means of quantifying estrogenic hormones in wastewater effluents and surface waters. Results from ELISA analysis of estrogenic hormones in secondary wastewater effluent indicate concentrations comparable to those that cause vitellogenesis in fish. Confirmatory analyses by GC/MS/MS are consistent with ELISA results. Effluent filtration, using sand filtration or microfiltration, removes approx. 70% of the hormones from secondary effluent, while advanced treatment, using reverse osmosis, removes more than 95% of hormones. The detection limits for estrogenic hormones are approx. 0.1 ng/L in wastewater effluent and 0.05 ng/L in surface water. The ELISA technique provides a relatively simple and practical method of assessing the fate of estrogenic hormones in engineered and natural systems.

Treatment of domestic wastewater by three plant species in constructed wetlands

Abstract: Three common Appalachian plant species (Juncus effusus L., Scirpus validus L., and Typha latifolia L.) were planted into small-scale constructed wetlands receiving primary treated wastewater. The experimental design included two wetland gravel depths (45 and 60 cm) and five planting treatments (each species in monoculture, an equal mixture of the three species, and controls without vegetation), with two replicates per depth planting combination. Inflow rates (19 L day 1 ) and frequency (3 times day 1 ) were designed to simulate full-scale constructed wetlands as currently used for domestic wastewater treatment in West Virginia. Influent wastewater and the effluent from each wetland were sampled monthly for ten physical, chemical and biological parameters, and plant demographic measurements were made. After passing through these trough wetlands, the average of all treatments showed a 70% reduction in total suspended solids (TSS) and biochemical oxygen demand (BOD), 50 to 60% reduction in nitrogen (TKN), ammonia and phosphate, and a reduction of fecal coliforms by three orders of magnitude. Depth of gravel (45 or 60 cm) had little effect on wetland treatment ability, but did influence Typha and Scirpus growth patterns. Gravel alone provided significant wastewater treatment, but vegetation further improved many treatment efficiencies. Typha significantly out-performed Juncus and Scirpus both in growth and in effluent quality improvement. There was also some evidence that the species mixture out-performed species monocultures. Typha was the superior competitor in mixtures, but a decline in Typha growth with distance from the influent pipe suggested that nutrients became limiting or toxicities may have developed.

Assessment of the impact of point source pollution from the Keiskammahoek Sewage Treatment Plant on the Keiskamma River - pH, electrical conductivity, oxygen- demanding substance (COD) and nutrients

Abstract: The treatment performance of the Keiskammahoek Sewage Treatment Plant (KSTP), was assessed in terms of pH, conductivity, and COD and nutrients removal from the influent The contributions from this and other smaller point sources in the town to the se parameters in the receiving Keiskamma River were determined by simultaneously monitoring the parameters in the river over a period of about 1 month The COD and orthophosphate in effluents exceed the SA Effluent Quality Standards for these parameters in effluents to be discharged into a river Also, significant pollution of the receiving Keiskamma River was indicated for orthophosphate, COD and NH 4 -N

Assessment of Potential Antibiotic Contaminants in Water and Preliminary Occurrence Analysis

Abstract: Antibiotics are among the emerging microcontaminants in water because of concerns of their potential adverse effects on the ecosystem and possibly on human health. Antibiotics are likely to be released into the aquatic environment via wastewater effluent and agricultural runoff as a result of incomplete metabolism, ineffective treatment removal or improper disposal because large quantities of antibiotics are used annually in human therapy and in agriculture. Despite large quantities of use, published data on the amounts and use patterns of antibiotics are scarce. To assess the magnitude of the potential risks associated with antibiotics, a comprehensive literature review was conducted on the usage, occurrence, and behavior of antibiotics. To identify antibiotics that are likely to be present in water sources, concentrations of antibiotics in municipal wastewater and animal waste in the United States (U.S.) were estimated and were classified according to chemical properties. The estimation of human health antibiotics was based upon the number of prescriptions administered. The estimated concentrations of antibiotics in untreated wastewater range from 3.9 ng/L to approximately 27,000 ng/L. The estimation of animal health antibiotics was based upon the subtherapeutic usage in feed for growth promoting. Considerable variation in antibiotic usage exists among different animal species. Reported data on the occurrence of antibiotics in the aquatic environment confirm the persistence of certain antibiotics. Although information is limited, studies on the transformation and sorption of antibiotics indicate that these processes significantly affect the fate of mo st classes of antibiotics. By combining information on environmental fate with the predicted concentrations, we identify that antibiotics of sulfonamides and fluoroquinolones are the most likely water contaminants, followed by macrolides. Among sulfonamide and fluoroquinolone antibiotics, sulfamethoxazole and ciprofloxacin are most likely to be present in municipal wastewater effluent and sulfamethazine is most likely to be present in agricultural runoff. Azithromycin and tylosin are the most likely macrolides present in municipal wastewater effluent and in agricultural runoff respectively. An occurrence study, which is currently underway, focuses on three of the potential antibiotic contaminants, ciprofloxacin, sulfamethoxazole and sulfamethazine, identified by literature review. Solid phase extraction methods were developed. Recoveries ranged from approximately 45 to 106 percent. Analysis of the three antibiotics was conducted by liquid chromatography mass spectrometry (LC-MS). Additionally, high performance liquid chromatography (HPLC) with fluorescence detection was employed for ciprofloxacin analysis. Preliminary results indicated the presence of ciprofloxacin in secondary wastewater effluent at approximately 80 to 150 ng/L. Sulfamethoxazole was detected in one of the wastewater samples. Sulfamethazine was not detected. Concentrations of antibiotics were found to be much lower or below the detection limits in the effluent of advanced treatment processes including granular activated carbon and ozonation, indicating significant removal by those processes.

Influence of Effluent Irrigation on Community Composition and Function of Ammonia-Oxidizing Bacteria in Soil

Abstract: The effect of effluent irrigation on community composition and function of ammonia-oxidizing bacteria (AOB) in soil was evaluated, using techniques of molecular biology and analytical soil chemistry. Analyses were conducted on soil sampled from lysimeters and from a grapefruit orchard which had been irrigated with wastewater effluent or fertilizer-amended water (FAW). Specifically, comparisons of AOB community composition were conducted using denaturing gradient gel electrophoresis (DGGE) of PCR-amplified fragments of the gene encoding the a-subunit of the ammonia monooxygenase gene (amoA) recovered from soil samples and subsequent sequencing of relevant bands. A significant and consistent shift in the population composition of AOB was detected in soil irrigated with effluent. This shift was absent in soils irrigated with FAW, despite the fact that the ammonium concentration in the FAW was similar. At the end of the irrigation period, Nitrosospiralike populations were dominant in soils irrigated with FAW, while Nitrosomonas-like populations were dominant in effluent-irrigated soils. Furthermore, DGGE analysis of the amoA gene proved to be a powerful tool in evaluating the soil AOB community population and population shifts therein. Agricultural irrigation with wastewater effluent is a common practice in arid and semiarid regions, and it is used as a readily available and inexpensive option to fresh water. However, irrigation with effluent has possible public health and environmental side effects, as effluents may contain pathogens and high levels of sodium, dissolved organic carbon, detergents, and toxic metals (22). Furthermore, the addition of such a “mixed bag” of compounds may cause significant shifts in structure and function of a microbial community, which in turn may influence the viability of the soil for agriculture. One important group of organisms that may be affected is the chemolithotrophic ammonia-oxidizing bacteria (AOB). The AOB, which are responsible for the first, rate-limiting step in nitrification in which ammonia (NH3) is transformed to nitrate (NO3 2 ) via nitrite (NO2 2 ), play a critical role in natural ni

A method for processing lignocellulosic material

Abstract: A method wherein lignocellulosic biomass materials are converted into combustible fuel products. In particular, the method is a continuous process, involving wet oxidation or steam explosion, for fermentatively converting such biomass materials into ethanol using a process design that permits all or part of the process water from the ethanol fermentation process to be recycled to reduce the consumption of process water. The effluent from the ethanol fermentation step may be subjected to an anaerobic fermentation step generating methane and a water effluent in which the amount of potentially inhibitory substances is at a sub-inhibitory level, which in turn permits all or part of the effluent water from the anaerobic fermentation step to be recycled into the process.

Assessing Ecological Impacts of Shrimp and Sewage Effluent: Biological Indicators with Standard Water Quality Analyses

Abstract: Despite evidence linking shrimp farming to several cases of environmental degradation, there remains a lack of ecologically meaningful information about the impacts of effluent on receiving waters. The aim of this study was to determine the biological impact of shrimp farm effluent, and to compare and distinguish its impacts from treated sewage effluent. Analyses included standard water quality/sediment parameters, as well as biological indicators including tissue nitrogen (N) content, stable isotope ratio of nitrogen (delta N-15) and amino acid composition of inhabitant seagrasses, mangroves and macroalgae. The study area consisted of two tidal creeks, one receiving effluent from a sewage treatment plant and the other from an intensive shrimp farm. The creeks discharged into the western side of Moreton Bay, a sub-tropical coastal embayment on the east coast of Australia. Characterization of water quality revealed significant differences between the creeks, and with unimpacted eastern Moreton Bay. The sewage creek had higher concentrations of dissolved nutrients (predominantly NO3-/NO2- and PO43-, compared to NH4+ in the shrimp creek). In contrast, the shrimp creek was more turbid and had higher phytoplankton productivity. Beyond 750 m from the creek mouths, water quality parameters were indistinguishable from eastern Moreton Bay values. Biological indicators detected significant impacts up to 4 km beyond the creek mouths (reference site). Elevated plant delta N-15 values ranged from 10.4-19.6 parts per thousand at the site of sewage discharge to 2.9-4.5 parts per thousand at the reference site. The free amino acid concentration and composition of seagrass and macroalgae was used to distinguish between the uptake of sewage and shrimp derived N. Proline (seagrass) and serine (macroalgae) were high in sewage impacted plants and glutamine (seagrass) and alanine (macroalgae) were high in plants impacted by shrimp effluent. The delta N-15 isotopic signatures and free amino acid composition of inhabitant flora indicated that sewage N extended further from the creek mouths than shrimp N. The combination of physical/chemical and biological indicators used in this study was effective in distinguishing the composition and subsequent impacts of aquaculture and sewage effluent on the receiving waters. (C) 2001 Academic Press.

Process for purification by combination of an effluent that contains carbon dioxide and hydrocarbons

Abstract: For the purification of an effluent that contains carbon dioxide and hydrocarbons resulting from a carbon dioxide-assisted recovery stage, the effluent is circulated in a gas-liquid separator ( 3 ) to recover C 3 + liquid and a gas that contains carbon dioxide and, for example, less than 10% of methane and ethane. Pressurized combustion ( 13 ) of the gas with air produced a combustion gas ( 21 ) enriched with carbon dioxide and water vapor. The combustion gas ( 21 ) is cooled ( 11 ) ( 22 ) to recover heat, and the cooled combustion gas is recycled under pressure by a compressor ( 27 ) to an injection well ( 29 ). Nitrogen is at least partly separated from the combustion gas before the recycling, and in an optional intermediate step the condensed water is also separated from the carbon dioxide. The invention has a particular application for the assisted recovery of petroleum by CO 2 with a reduction of the greenhouse effect.

Characterization of estrogenic compounds in water samples collected from United Kingdom estuaries

Abstract: This report describes the identification of important estrogenic compounds in surface and sediment pore-water samples collected from the Tyne and Tees estuaries (United Kingdom) through the application of toxicity identification evaluation (TIE) procedures. The Tyne and Tees estuaries represent estuaries that have been historically impacted by industrial activities and continue to receive treated domestic sewage and industrial effluent. In 1998, Dabholm Gut on the Tees received a mixture of treated and untreated effluent, while Howdon sewage treatment works (STW) discharged primary treated effluents. An estrogenically active water sample collected from Howdon STW on the Tyne was shown to contain 17β-estradiol, androsterone, and an unknown estrogenic compound(s). Most of the activity contained in a sample collected from the Dabholm Gut combined discharges on the Tees was also due to 17β-estradiol with additional activity from nonylphenol and (tentatively) bis(2-ethylhexyl)phthalate. The only sediment pore-water sample to demonstrate estrogenic activity was collected from Dabholm Gut.

Electrochemical oxidation of tannery wastewater

Abstract: Tannery wastewater was treated by an electrochemical oxidation method using Ti/Pt, Ti/PbO2 and Ti/MnO2 anodes and a Ti cathode in a two-electrode stirred batch reactor. The changes in colour concentration, chemical oxygen demand (COD), ammonia (NH4+), sulfide and total chromium have been determined as a function of treatment time and applied current density. Gas chromatography–mass spectrometry (GC–MS) analysis, performed on the wastewater samples before and after treatment, as well as on foam samples, is reported. Anode efficiency, rate constants and energy consumption were estimated and discussed. The efficiency of Ti/Pt was 0.802 kgCOD h−1 A−1m−2 and 0.270 kgNH4+ h−1 A−1m−2, and the energy consumption was 5.77 kWh kg−1 COD and 16.63 kWh kg−1 of NH4+. The order of efficiency of anodes was found to be Ti/Pt ≫ Ti/PbO2 > Ti/MnO2. The results indicate that the electro-oxidation method could be used for effective oxidation of tannery wastewater and a final effluent with substantially reduced pollution load can be obtained. © 2001 Society of Chemical Industry

Wastewater treatment system

Abstract: Wastewater treatment systems and processes for: removal of solids, pathogens, nitrogen, and phosphorus from municipal and agricultural wastewater include nitrification of wastewater and increasing the pH of the nitrified wastewater by adding a metallic-containing salt and hydroxide to precipitate phosphorus to form a useable effluent having a specified nitrogen:phosphorus ratio that is useful as a fertilizer or spray for remediation of contaminated soils. The presence of infectious microorganism such as enteropathogenic bacteria and picarnoviruses will be reduced in the useable effluent. The precipitated phosphorus is recovered and used to form useable phosphorus products.

Organic Removal of Anaerobically Treated Leachate by Fenton Coagulation

Abstract: The leachate from a Hong Kong landfill, containing 15,700 mg/L of chemical oxygen demand (COD) and 2,260 mg/L of ammonia nitrogen (NH3–N), was first treated in a UASB (upflow anaerobic sludge blanket) reactor at 37°C. The process on average removed 90.4% of COD with 6.6 days of hydraulic retention at an organic loading rate of 2.37 g of COD/L⋅day. The UASB effluent was further treated by the Fenton coagulation process using H2O2 and Fe2+. Under the optimal condition of 200 mg of H2O2/L and 300 mg of Fe2+/L and an initial pH of 6.0, 70% of residual COD in the UASB effluent was removed, of which 56% was removed by coagulation/precipitation and only 14% by free radical oxidation. It is obvious that H2O2 and Fe2+ had a strong synergistic effect on coagulation. The average COD in the final effluent was 447 mg/L. Removing each gram of COD required 0.28 g of Fe2+ and 0.18 g of H2O2.

Iron and aluminum hydroxy (oxide) coated filter media for low-concentration phosphorus removal

Abstract: The presence of phosphates in water and wastewater negatively affects the aquatic environment. Several processes have been used for the removal of phosphorus from water and wastewater; however, most failed in attaining removal levels that will alleviate the problems associated with its presence. In this study, laboratory experiments were conducted to determine the efficacy of iron aluminum hydroxy (oxide) coated filter media in removing low concentrations of phosphates. Two media (silica sand and olivine) were used in the experiments, and tests were conducted on distilled water, artificial groundwater, tap water, and treated wastewater. The effect of flowrates, ranging from 10 to 80 mL/min (3.4 to 27.2 m 3 /m 2 .h), on phosphate removal efficiencies was evaluated for distilled water. Results indicate that the process was very effective in phosphate removal (more than 90%) present in low concentrations (approximately 0.5 mg/L) when applied to distilled water and artificial groundwater and with less success when applied to tap water (less than 80%) and treated wastewater effluent (less than 70%). This reduced removal may be attributed to the presence of competing species and, in this case, in the form of sulfates. The results also show that, for distilled water, the treated pore volumes before breakthrough (set at 0.1 mg/L) ranged from 137 to 348 pore volumes (51 to 129 bed volumes) for sand and 245 to 370 pore volumes (100 to 152 bed volumes) for olivine, depending on the flowrates. The results for distilled water further indicated that the flowrates used in the experiments had negligible effect on the removal efficiency of the process, and operating rates of 27 m 3 /m 2 .h could be applied to distilled water with negligible negative effects.