Showing papers on "Effluent published in 2004"
TL;DR: It is demonstrated here that it is also possible to produce electricity in a MFC from domestic wastewater, while at the same time accomplishing biological wastewater treatment (removal of chemical oxygen demand; COD), which may represent a completely new approach to wastewater treatment.
Abstract: Microbial fuel cells (MFCs) have been used to produce electricity from different compounds, including acetate, lactate, and glucose. We demonstrate here that it is also possible to produce electricity in a MFC from domestic wastewater, while atthe same time accomplishing biological wastewater treatment (removal of chemical oxygen demand; COD). Tests were conducted using a single chamber microbial fuel cell (SCMFC) containing eight graphite electrodes (anodes) and a single air cathode. The system was operated under continuous flow conditions with primary clarifier effluent obtained from a local wastewater treatment plant. The prototype SCMFC reactor generated electrical power (maximum of 26 mW m(-2)) while removing up to 80% of the COD of the wastewater. Power output was proportional to the hydraulic retention time over a range of 3-33 h and to the influent wastewater strength over a range of 50-220 mg/L of COD. Current generation was controlled primarily by the efficiency of the cathode. Optimal cathode performance was obtained by allowing passive air flow rather than forced air flow (4.5-5.5 L/min). The Coulombic efficiency of the system, based on COD removal and current generation, was < 12% indicating a substantial fraction of the organic matter was lost without current generation. Bioreactors based on power generation in MFCs may represent a completely new approach to wastewater treatment. If power generation in these systems can be increased, MFC technology may provide a new method to offset wastewater treatment plant operating costs, making advanced wastewater treatment more affordable for both developing and industrialized nations.
1,459 citations
TL;DR: Use of Fe2+/H2O2/UV combination seems to show a satisfactory COD and color removal performance and to be economically more viable choice for the acetate and polyester fiber dyeing effluent on the basis of 90% removal.
518 citations
TL;DR: A considerable risk and impact of heavy metals and pesticides on human health in the exposed areas receiving the wastewater from the STPs indicates a definite adverse impact on the environmental quality of the disposal area.
510 citations
TL;DR: The use of galactomannans derived from plants in this system presents a sustainable method of effluent treatment and the raw materials are derived from renewable plant sources and are available in tonnage quantities, the adsorption system itself is highly effective and does not involve any additional chemical input or treatment other than the use of the adsorbent.
Abstract: Dyeing effluent is one of the largest contributors to textile effluent and such colored wastewater has a seriously destructive impact on the environment. Adsorption can be a very effective treatment for decolorization of textile dyeing effluent, but current techniques employ adsorption chemistry that is not particularly environmentally friendly, such as the use of alum. In this study, natural polysaccharides were used as adsorbents for removal of dye molecules from effluent. The results showed that naturally cationic polysaccharides such as chitin and chitosan gave excellent levels of color removal, and this was attributed to a combination of electrostatic attraction, van der Waals forces, and hydrogen bonding. Nonionic galactomannans (locust bean gum, guar gum, cassia gum) were also highly effective in removing dye from effluent, whereas other nonionic polysaccharides, such as starch, were not effective. This was attributed to the structure of the polysaccharides and the relative degree of inter- and intramolecular interactions between separate polymer chains. The pendant galactose residues of galactomannans prevented strong interaction, allowing greater hydrogen bonding with dye; comparatively, starch has extensive chain interactions, and as such had limited potential for hydrogen bonding with the dye molecules at the temperature of application. In addition, hydrophobic interactions between the hydrophobic parts of the dye and the alpha-face of the pendant galactose residues may have contributed to the superior performance. Repulsion between anionic polysaccharides and the dye anions prevented any hydrogen bonding and as such pectin, carrageenans, and alginic acid were not effective in dye removal from effluent. The use of galactomannans derived from plants in this system presents a sustainable method of effluent treatment. The raw materials are derived from renewable plant sources and are available in tonnage quantities, the adsorption system itself is highly effective and does not involve any additional chemical input or treatment other than the use of the adsorbent, and the adsorption agents themselves are nontoxic and biodegradable.
393 citations
TL;DR: Rice husks were investigated as a potential decontaminant of toxic heavy metals present in laboratory effluents and the ability to take up other metals species, such as Al, Cd, Cu, Pb and Zn, present in this effluent was studied.
350 citations
TL;DR: A review of human excretion included conjugation and metabolism of the natural and synthetic steroid estrogens within the body, together with quantities excreted in the urine and feces by different members of the population to enable sewage works influent and effluent concentration predictions to be made.
Abstract: To predict sewage influent and effluent concentrations of the steroid estrogens 17β-estradiol, estrone, and 17α-ethinylestradiol, a review of human excretion was carried out. This included conjugation and metabolism of the natural and synthetic steroid estrogens within the body, together with quantities excreted in the urine and feces by different members of the population. This has been combined with fate and behavior information for conjugated and unconjugated estrogens in the sewage treatment system to enable sewage works influent and effluent concentration predictions to be made. The model has proved to be reasonably accurate when tested against recent measurements of these steroid estrogens in the influent and effluent of sewage treatment works. The model may be used with river dilution ratios to predict which sewage treatment works are most likely to cause the greatest endocrine disruption due to steroid estrogens.
334 citations
01 Jan 2004
TL;DR: In this article, an overview of basis and treatment efficiency for different AOPs are considered and presented according to their specific features for textile wastewater treatment, and a detailed analysis of their performance is presented.
Abstract: The use of conventional textile wastewater treatment processes becomes drastically challenged to environmental engineers with increasing more and more restrictive effluent quality by water authorities. Conventional treatment such as biological treatment discharges will no longer be tolerated as 53% of 87 colours are identified as non-biodegradable. Advanced oxidation processes hold great promise to provide alternative for better treatment and protection of environment, thus are reviewed in this paper. An overview of basis and treatment efficiency for different AOPs are considered and presented according to their specific features.
306 citations
TL;DR: The potential reuse of chromium-containing seaweed for the preparation of basic chromium sulfate (tanning agent) has been demonstrated and Fourier transform infrared spectroscopy, energy-dispersive X-ray analysis, and flame photometry studies have been carried out to understand the mechanistic pathway for the removal of Chromium.
Abstract: The presence of chromium in the effluent is a major concern for the tanning industry. Currently, chemical precipitation methods are practiced for the removal of chromium from the effluent, but that leads to the formation of chrome-bearing solid wastes. The other membrane separation and ion exchange methods available are unfeasible due to their cost. In this study, the removal of chromium from tannery effluent has been carried out using abundantly available brown seaweed Sargassum wightii. Simulated chrome tanning solution was used for the standardization of experimental trials. Various factors influencing the uptake of chromium, viz., quantity of seaweed, concentrations of chromium, pH of the chrome-bearing wastewater, and duration of treatment, have been studied. Chemical modification of the seaweed through pretreatment with sulfuric acid, magnesium chloride, and calcium chloride showed improved uptake of chromium. Langmuir and Freundlich isotherms have been fitted for various quantities of seaweed. The dynamic method of treatment of protonated seaweed with simulated chrome tanning solution at a pH of 3.5-3.8 for a duration of 6 h gave the maximum uptake of about 83%. A similar uptake has been established for commercial chrome tanning wastewater containing the same concentration of chromium. The Sargassum species exhibited a maximum uptake of 35 mg of chromium per gram of seaweed. Fourier transform infrared spectroscopy, energy-dispersive X-ray analysis, and flame photometry studies have been carried out to understand the mechanistic pathway for the removal of chromium. The potential reuse of chromium-containing seaweed for the preparation of basic chromium sulfate (tanning agent) has been demonstrated.
280 citations
TL;DR: Characterisation of grey water reveals a source water that is similar in organic strength to a low-medium strength municipal sewage influent but with physical and biodegradability characteristics similar to a tertiary treated effluent.
267 citations
TL;DR: Based on the loading analysis, the total PBDE concentrations loaded to the San Francisco Estuary through effluent discharge from this wastewater treatment plant is 2 lb/year (0.9 kg/year).
Abstract: Polybrominated diphenyl ethers (PBDEs) are commonly used flame-retardants that are now ubiquitous environmental contaminants. Wastewater treatment plants are one source of PBDEs to the environment through their discharge of treated effluent and land application of sewage sludge. Effluent and sludge were collected and analyzed for PBDEs at a wastewater treatment plant in California. The total concentration of PBDEs ranged from 61 to 1440 μg/kg dry wt in the sludge and from 4 to 29 000 pg/L in discharged effluent. The congeners with the highest abundance in sludge were BDE-47, BDE-99, and BDE-209, while in treated effluent BDE-47 and BDE-99 were the most abundant. BDE-47 and BDE-99 are major congeners of the penta-formulation, while BDE-209 composes the deca-formulation. The sum of the major congeners in the penta-formulation (BDE-47, 99, 100, 153, and 154) comprises 88% of the total PBDEs in the effluent, while BDE-209 is only 6%. Based on the loading analysis, the total PBDE concentrations loaded to the S...
222 citations
TL;DR: A full detailed design of a potential application based on Granular sludge Sequencing Batch Reactors showed that the GSBR technology was less sensitive to the land price and more sensitive to a rain weather flow, and became more attractive at lower permissible RWF/DWF ratios and higher land prices.
TL;DR: In this paper, the fate and transport of selected emerging contaminants during bank filtration at two transects in Berlin, Germany was investigated. But the results were limited to the removal of impurities.
Abstract: Bank filtration and artificial ground water recharge are important, effective, and cheap techniques for surface water treatment and removal of microbes, as well as inorganic, and some organic, contaminants. Nevertheless, physical, chemical, and biological processes of the removal of impurities are not understood sufficiently. A research project titled Natural and Artificial Systems for Recharge and Infiltration attempts to provide more clarity in the processes affecting the removal of these contaminants. The project focuses on the fate and transport of selected emerging contaminants during bank filtration at two transects in Berlin, Germany. Several detections of pharmaceutically active compounds (PhACs) in ground water samples from bank filtration sites in Germany led to furthering research on the removal of these compounds during bank filtration. In this study, six PhACs including the analgesic drugs diclofenac and propyphenazone, the antiepileptic drugs carbamazepine and primidone, and the drug metabolites clofibric acid and 1-acetyl-1-methyl-2-dimethyl-oxamoyl-2-phenylhydrazide were found to leach from the contaminated streams and lakes into the ground water. These compounds were also detected at low concentrations in receiving public supply wells. Bank filtration either decreased the concentrations by dilution (e.g., for carbamazepine and primidone) and partial removal (e.g., for diclofenac), or totally removed PhACs (e.g., bezafibrate, indomethacine, antibiotics, and estrogens). Several PhACs, such as carbamazepine and especially primidone, were readily transported during bank filtration. They are thought to be good indicators for evaluating whether surface water is impacted by contamination from municipal sewage effluent or whether contamination associated with sewage effluent can be transported into ground water at ground water recharge sites.
TL;DR: The purpose of the research was to demonstrate the coupling of two state-of-the-art techniques: a time-weighted polar organic chemical integrative sampler (POCIS) and microliquid chromatography–electrospray/ion-trap mass spectrometry to detect six drugs in a real-world environment, e.g., waste water effluent.
Abstract: The purpose of the research presented in this paper was twofold: (1) to demonstrate the coupling of two state-of-the-art techniques: a time-weighted polar organic chemical integrative sampler (POCIS) and microliquid chromatography–electrospray/ion-trap mass spectrometry and (2) to assess the ability of these methodologies to detect six drugs (azithromycin, fluoxetine, omeprazole, levothyroxine, methamphetamine, methylenedioxymethamphetamine [MDMA]) in a real-world environment, e.g., waste water effluent. In the effluent from three wastewater treatment plants (WWTPs), azithromycin was detected at concentrations ranging from 15 to 66 ng/L, which is equivalent to a total annual release of 1 to 4 kg into receiving waters. Detected and confirmed in the effluent from two WWTPs were two illicit drugs, methamphetamine and MDMA, at 2 and 0.5 ng/L, respectively. Although the ecotoxicologic significance of drugs in environmental matrices, particularly water, has not been closely examined, it can only be surmised that these substances have the potential to adversely affect biota that are continuously exposed to them even at very low levels. The potential for chronic effects on human health is also unknown but of increasing concern because of the multiuse character of water, particularly in densely populated, arid areas.
TL;DR: A photodegradation study of triclosan, a commonly used antimicrobial agent, was carried out in order to investigate the formation of dibenzodichlorodioxin as a byproduct of photodegrad in various environmental matrices and under different conditions.
TL;DR: A conceptual model is presented for determining which currently prescribed pharmaceutical compounds are most likely to be found in sewage, and for estimating their concentrations, both in raw sewage and after successive stages of secondary sewage treatment.
TL;DR: Three units of a sub-surface horizontal flow constructed wetland (CW) pilot plant in polishing effluent from the upflow anaerobic sludge blanket (UASB) reactor plant in Tanzania showed better performance for the vegetated units B and C were obtained compared to the control unit A, indicating that pH increased from the influent to the effluent and that DO increase was related to the decrease of temperature.
TL;DR: Agronomic results indicate no major limitations to the use of a tertiary effluent as an irrigation source in an ornamental plant nursery, and the nutrient content of the tertiaries effluent was able to maintain good plant growth as well as fertigated water for most of the tested species.
TL;DR: A continuous flow, free water surface (FWS) pilot wetland using the duckweed plant Lemna gibba L. was constructed at the Blaustein Institute for Desert Research in Kiryat Sde Boker of the Negev, Israel, and operated on domestic primary effluents, where hydraulic efficiency in the system was high and allowed good settling conditions.
TL;DR: In this article, central composite design experiment is used to study the effect of ozone treatment for acid dye effluents and to optimise the variables such as salt concentration, pH and time, which influence the efficiency of colour and COD removal of dye.
TL;DR: Photocatalytic oxidation using an thin gap annular UV reactor with TiO2 was used to break down the colour of a synthetic effluent, and the presence of the combination of high dissolved oxygen and sodium chloride was found to enhance the decolorization and mineralization rates of the reactive dye.
TL;DR: It is concluded that E1 and E2 were the dominant environmental estrogens in the STP effluent, but a significant contribution to estrogenic activities stems from unidentified components in the effluents.
Abstract: In order to identify the dominant contributors to estrogenic activity in environmental waters, a comprehensive fractionation method using silica gel column chromatography, combined with recombinant yeast assay for detecting estrogenic activity and with gas chromatography–mass spectrometry for quantifying endocrine disruptors and natural estrogens, was developed. The method was applied to the municipal sewage treatment plant (STP) secondary effluent discharged to the Tamagawa River in Tokyo, Japan, where endocrine disruption was observed in wild carp. The instrumental analysis demonstrated that averaged concentrations of nonylphenol, bisphenol A, estrone (E1), and 17β-estradiol (E2) were 564 ± 127, 27 ± 19, 33 ± 11, and 4.6 ± 3.0 ng/L, respectively. Based on the concentration and relative potency of these compounds, the natural estrogens E1 and E2 represented more than 98% of the total estrogen equivalent concentration (EEQ) in the STP effluent, while the contribution of phenolic compounds to total EEQ was less than 2%. Estrogenic activities associated with the dissolved phase of the effluent samples were detected by a recombinant yeast assay. By using silica gel column chromatography, the dissolved phase was separated into several fractions that were subjected to the bioassay. The polar fractions exhibited estrogenic activity. The greatest estrogenic activity was found in a polar fraction containing E1 and E2 and represented 66 to 88% of the total estrogenic activities estimated from the bioassay data. These results lead to the conclusion that E1 and E2 were the dominant environmental estrogens in the STP effluent, but a significant contribution to estrogenic activities stems from unidentified components in the effluents.
Louisiana State University1, Western Washington University2, Louisiana Department of Environmental Quality3, United States Army Corps of Engineers4, United States Environmental Protection Agency5, Clemson University6, Tulane University7, Texas A&M University8, University of New Orleans9, University of Louisiana at Lafayette10
TL;DR: In this article, the use of wetlands for treatment of wastewaters has a number of important ecological and economic benefits, such as improved effluent water quality, increased accretion rates to help offset subsidence, increased productivity of vegetation, and financial and energy savings of capital not invested in conventional tertiary treatment systems.
TL;DR: Electrocoagulation with Al/Fe electrode pair was very efficient and able to achieve 99% copper ion and 96.5% turbidity removal in less than 30 min and the COD removal obtained in the treatment was better than 85%, with an effluent COD below 100 mgl(-1).
TL;DR: In this view, experiments were conducted in which the removal of 17alpha-ethynylestradiol (EE2), a synthetic and persistent estrogen, from water was monitored in three upstream bioreactors filled with sand, granulated activated carbon (GAC) and MnO(2) granules.
TL;DR: The use of advanced oxidation processes to remove pollutants in various water treatment applications has been the subject of study for around 30 years and its exact position in the range of water treatment processes has not been determined to date.
TL;DR: The simple design and relatively low operating costs, due to low costs of added chemicals and low energy input, combined with excellent treatment performance, means that this system can be used as a novel domestic wastewater treatment system for developing countries.
TL;DR: In this paper, the performance of rapid sand filters was evaluated in three tertiary wastewater treatment plants in the State of Kuwait, and the results indicated significant improvements, at 95% and 99% significance levels, in solids (SS, VSS) and organics (BOD, COD) removal by sand filtration.
TL;DR: The studies focus on the influence of the solids retention time (SRT) on the removal efficiency, as the SRT is the most important parameter in the design of STPs.
TL;DR: It is suggested that the effluent from SSFCW was appropriate for further treatment in land applications for nutrient assimilation, and water hyacinth made only a minimal contribution to the removal of nutrients.
TL;DR: The coagulation-flocculation-decantation process used to optimize water recovery from the concentrate shows that it is possible to recycle a great volume of water using a small decanter area, since the concentrate flow rate is low.