Showing papers on "Effluent published in 2000"
TL;DR: In this paper, three different tubular flow reactors were used to produce high yields of gas with a high content of hydrogen (57 mol %) at the highest temperatures employed in this work, and all three reactors plugged after 1−2 h of use with feedstocks.
Abstract: Biomass feedstocks, including corn- and potato-starch gels, wood sawdust suspended in a cornstarch gel, and potato wastes, were delivered to three different tubular flow reactors by means of a “cement” pump. When rapidly heated to temperatures above 650 °C at pressures above the critical pressure of water (22 MPa), the organic content of these feedstocks vaporized. A packed bed of carbon within the reactor catalyzed the gasification of these organic vapors in the water; consequently, the water effluent of the reactor was clean. The gas was composed of hydrogen, carbon dioxide, methane, carbon monoxide, and traces of ethane. Its composition was strongly influenced by the peak temperature of the reactor and the condition of the reactor's wall. Extraordinary yields (>2 L/g) of gas with a high content of hydrogen (57 mol %) were realized at the highest temperatures employed in this work. Irrespective of the reactor geometry and method of heating, all three reactors plugged after 1−2 h of use with feedstocks t...
592 citations
TL;DR: A review of realistic aquaculture waste solids management strategies can be found in this paper, where the main reason for treating solids to be discharged from flow-through systems is to reduce potential negative impacts on the surrounding aquatic environment.
360 citations
TL;DR: Beta-estradiol equivalent concentrations (EEQ) were 58 and 70 ng/l in the influent and 6 ng/L in the effluent, indicating that the load of estrogenic activity of the wastewater was reduced by about 90% in the sewage plant, and less than 3% of the estrogenicactivity was found in the sludge.
337 citations
TL;DR: Although only a simple qualitative HPLC method was used, colour removal, toxicity and TON removal all support its usefulness in analysing biotreatment of azo dyes.
Abstract: Decolorisation of azo dyes during biological effluent treatment can involve both adsorption to cell biomass and degradation by azo-bond reduction during anaerobic digestion. Degradation is expected to form aromatic amines, which may be toxic and recalcitrant to anaerobic treatment but degradable aerobically. Methods for the quantitative detection of substituted aromatic amines arising from azo-dye cleavage are complex. A simple qualitative method is suggested as a way in which to investigate whether decolorisation is actually due to degradation, and whether the amines generated are successfully removed by aerobic treatment. Samples from a combined anaerobic-aerobic system used for treating a simulated textile wastewater containing the reactive azo dye Procion Red H-E7B were analysed by high-performance liquid chromatoraphy/ultraviolet (HPLC-UV) methods. Anaerobic treatment gave significant decolorisation, and respiration-inhibition tests showed that the anaerobic effluent had an increased toxicity, suggesting azo-dye degradation. The HPLC method showed that more polar, UV-absorbing compounds had been generated. Aerobically, these compounds were removed or converted to highly polar compounds, as shown by HPLC analysis. Since the total organic nitrogen (TON) decreased aerobically as organic N-containing compounds were mineralised, aromatic amine degradation is suggested. Although only a simple qualitative HPLC method was used, colour removal, toxicity and TON removal all support its usefulness in analysing biotreatment of azo dyes.
325 citations
TL;DR: It was established that the concentrations of natural steroid estrogens and xenoestrogens in a treated sewage effluent fluctuated temporally (over 8 months), from between 36 and 308 ng/L and between <0.2 (detection limit) and 10.7 μg/L, respectively.
Abstract: Sewage treatment works (STW) effluents throughout the U.K. have been shown to be estrogenic, inducing vitellogenin (VTG) synthesis in caged and wild fish for considerable distances (up to several kilometers) downstream of the effluent discharge. Thresholds for vitellogenin induction in caged fish in those studies have been derived from short-term exposures, and may not necessarily be representative of thresholds for estrogenic responses in wild fish living in rivers that contain STW effluent. In addition, very little is known about the long-term fluctuations in the concentrations of the estrogenic components of STW effluents. In this paper, it was established that the concentrations of natural steroid estrogens and xenoestrogens (alkylphenolic chemicals) in a treated sewage effluent fluctuated temporally (over 8 months), from between 36 and 308 ng/L and between <0.2 (detection limit) and 10.7 μg/L, respectively. Long-term exposure of maturing adult roach to a graded concentration of this effluent (0, 9.4,...
321 citations
TL;DR: In this article, the authors used carrier magnetic materials for more effective separation of water and solids, as well as the oxidation pretreatment that is also used to sterilize the water.
293 citations
TL;DR: In this article, the electro-Fenton method assisted by chemical coagulation was employed and found to be highly efficient in removing a large amount of refractory organic and inorganic compounds in the leachate.
251 citations
TL;DR: Molecular mass distribution showed that high molecular mass compounds were almost completely degraded and showed a low acute toxicity as compared to the initial values and AOX values are strongly reduced after the photocatalytic oxidation.
226 citations
TL;DR: In this paper, a combined anaerobic-aerobic system was used for piggery wastewater for organic carbon and nitrogen removal in a laboratory-scale sequencing batch reactor with a cycle length of 24 hours.
208 citations
TL;DR: The HRAP offers a good treatment system for sago starch factory wastewater that reduces chemicaloxygen demand, ammoniacal-nitrogen and phosphate Levels of the digested effluent reached 98.0%, 99.9% and 99.4% respectively.
Abstract: Wastewater arising from the production of sago starchhas a high carbon to nitrogen ratio, which is improvedwith anaerobic fermentation in an upflow packed beddigester The digested effluent with an average C: N:P ratio of 24: 014: 1 supported growth of Spirulina platensis (Arthrospira) with anaverage specific growth rate (μ) of 051day-1 compared with the average μ of 054day-1 in the inorganic Kosaric Medium in a highrate algal pond Supplementation with 6 mM urea and21 mM K2HPO4 produced gross biomassproductivity of 144 g m-2 day-1 Aflow-rate of 24 cm s-1 increased the μ andgross biomass productivity (18 g m-2 day-1) The highest crude protein, carbohydrate and lipidcontents of the biomass were 68%, 23% and 11%,respectively Percentage reductions in chemicaloxygen demand, ammoniacal-nitrogen and phosphatelevels of the digested effluent reached 980%, 999%and 994% respectively The HRAP offers a goodtreatment system for sago starch factory wastewater
207 citations
TL;DR: In this paper, the mobilisation and statistical analysis of potentially toxic elements in soil and plants of fields irrigated with mixed industrial effluent have been undertaken for productive utilisation of effluent-contaminated agricultural land.
Abstract: For productive utilisation of effluent–contaminated agricultural land, mobilisation and statistical analysis of potentially toxic elements in soil and plants of fields irrigated with mixedindustrial effluent have been undertaken. Total Fe,Mn, Zn, Cu, Pb, Ni and Cr have been estimated in soiland plant species of contaminated and noncontaminatedsites. 18 plants species and 18 root adjacent soilsamples from contaminated Kalipur area and 11 plantsspecies and 11 root adjacent soil samples fromuncontaminated Madhabpur area comprising majorcrops, vegetables and weeds have been included in thestudy. It is revealed that Hibiscusesculentus, Lycopersicon esculentum and Luffa acutangula growing in effluent–contaminated field show mobilisation ratio 0.5 and simultaneously exhibithealthy gigantic morphology at the early floweringstage. Coriandrum sativum, Raphhanussativus, Solanum melongena, Spinaceaoleracea, Oryza sativum, Brassica oleraceashowed mobilization ratio >0.5 butmaintained normal growth. Based on mobilization ratioand external morphology, we suggest the cultivation ofplants H. esculentus, L. acutangula, L. esculentum in land irrigated with industrial effluent. The highest andsecond highest enrichment factor (EFpp)was found for Cd and Pb, respectively. Pearson'scorrelation coefficient indicated that the metal levelin soil is not the main factor governing metaluptake. This study will help in selecting plantspecies for cultivation in contaminated fields.
TL;DR: In this article, a series of treatment steps composed of settling, centrifugation, and filtration was consecutively used to condition Olive Mill effluent (OME) wastewater, and the filtrate was then subjected to a post-treatment process, namely adsorption on activated clay.
TL;DR: In this paper, the authors investigated the pretreatment of a tannery wastewater, typified by the mixed effluent from tannery operations, and demonstrated 41.5% removal of total chemical oxygen demand (COD), 83.2% of chromium and 76.1% of suspended solid after 3h of plain settling.
TL;DR: It is reasoned that 5-15% precipitator fly ash, and less than 30% lagoon fly ash could be added to coarse sands to produce an infiltration bed, which would result in a better quality effluent than can be obtained with untreated sand alone.
TL;DR: In this article, the authors investigated the contribution of one possible regulator (carbon supply) to rates of activity of three enzymes involved in organic matter decomposition in constructed wetlands and found that by manipulating the quantity and quality of carbon supply, it may be possible to modify extracellular enzyme activities in order to maximize the efficiency of water treatment.
Abstract: Regulation of extracellular enzyme activity in constructed wetlands (i.e. artificial wetlands for wastewater treatment) has not been elucidated; the objective of this work was to investigate the contribution of one possible regulator (carbon supply) to rates of activity of three enzymes involved in organic matter decomposition. Soil samples from a constructed wetland were supplied with carbon (cellulose or glucose) at different concentrations (10 and 100 mg l −1 ) and with carbon-free water (control) or sewage effluent. The activities of β- d -glucosidase, phosphatase and arylsulphatase in the soil were monitored over a 54-day period using methylumbelliferyl substrates, which are cleaved only extracellularly ( Jones 1990 ). When compared to controls receiving no carbon, phosphatase activity under all treatments showed no significant differences over the course of the experiment. Sulphatase activities over the course of the experiment were significantly reduced by glucose (10 and 100 mg l −1 ), cellulose (10 and 100 mg l −1 ) and sewage effluent addition, to between 53 and 79% of the activity in controls. β-glucosidase activity gradually increased by 127–161% over the 54 d in response to cellulose addition (10 and 100 mg l −1 ), and decreased after sewage effluent addition to 84% of the activity in controls. These findings suggest that by manipulating the quantity and quality of carbon supply in constructed wetlands, it may be possible to modify extracellular enzyme activities in order to maximize the efficiency of water treatment.
Patent•
01 Sep 2000
TL;DR: In this article, a cost-effective process for separating contaminants and a wide range of fouling material from surface water, ground water and from industrial effluents is proposed, where cationic inorganic and/or polymeric flocculants are used to coagulate and focculate the water-borne colloidal matter (e.g. clays, iron hydroxides, naturally occurring matter (NOM's), followed by filtration using a multi-media filter, charge neutralization and reversal and final filtraction using a 5-
Abstract: This invention discloses a cost-effective process for separating contaminants and a wide-range of fouling material from surface water, ground water and from industrial effluents. Having undergone effective pre-treatment, the water can be purified further by using high-surface area spirally wound micro-filtration (MF), ultra-filtration (UF), nano-filtration (NF) or reverse osmosis (RO) membranes. High-quality potable water free from pathogen and other contaminants is thus produced at low-cost from the pre-treated surface water and ground-water. Conversely, pre-treated industrial effluents are further purified at a relatively low-cost using NF or RO membranes, thus producing water suitable for recycle or surface discharge. The process of this invention uses cationic inorganic and/or polymeric flocculants to coagulate and flocculate the water-borne colloidal matter (e.g. clays, iron hydroxides, naturally occurring matter (NOM's), etc.), followed by filtration using a multi-media filter, charge neutralization and reversal and final filtration using a 5-micron cartridge filter. These pre-treatment steps provides a good quality water having a low Silt Density Index and a significant negative zeta potential, thereby ensuring against irreversible chemical fouling of the spirally-wound membranes.
TL;DR: Results revealed that human estrogens are major causative substances in terms of estrogenic activity in sewage and its treated effluent and proper management should be established in the sewage treatment process which receives various environmental contaminants.
TL;DR: In this paper, the performance of a granular-bed anaerobic baffled reactor (GRABBR) used in the treatment of a whisky distillery wastewater was reported, with up to 80% COD (or 90% BOD) removal.
TL;DR: The challenge of eight of the 41 geographic isolates with full-strength swine lagoon effluent in the greenhouse led to the selection of three that are promising as genotypes to be grown on lagoons effluent.
TL;DR: In this paper, the determination of sulphide present in tannery waste water by two different methods namely, iodimetry and ion selective electrode (ISE) has been critically analysed.
TL;DR: Colour removal of textile dyes from effluent was evaluated using a laboratory ‘upflow anaerobic sludge blanket’ reactor and results indicate that the purified dye is more toxic to the biomass than the commercial one.
Abstract: Colour removal of textile dyes from effluent was evaluated using a laboratory ‘upflow anaerobic sludge blanket’ reactor. Several commercial dyes were selected to study the effect of dye structure on colour removal. The anaerobic reactor was fed with glucose, an easily biodegradable organic matter and selected individual dyes. Results show that some of the dyes are readily reduced under anaerobic conditions even at a high concentration of 700 mg/l. The average removal efficiency for acid dyes using this method was between 80 and 90% and that observed for the direct dye used was 81%. Laboratory experiments using the anaerobic reactor with disperse dyes, such as an anthraquinonebased dye, were unsuccessful even at low concentrations of 35 mg/l. Additional experiments were conducted to evaluate the toxicity of a selected disperse dye to an anaerobic environment. Results indicate that the purified dye is more toxic to the biomass than the commercial one.
TL;DR: In this paper, the effects of discharging the effluents of a leather complex on the concentrations of some potentially toxic elements (Cu, Fe, Mn, Zn, Al, As, Cr and Ni) in sewage water and irrigation with contaminated sewage water were studied near Jalandhar city, Punjab, in northwestern India.
Abstract: Sewage water is used for irrigation to improve crop yields, but it may affect the soil and crop quality. The effects of discharging the effluents of a leather complex on the concentrations of some potentially toxic elements (Cu, Fe, Mn, Zn, Al, As, Cr and Ni) in sewage water and the effects of irrigation with contaminated sewage water on the concentrations of these elements in soils and in potato (Solanum tuberosum L.) leaves and tubers were studied near Jalandhar city, Punjab, in northwestern India. Two treatments were 10 yr of irrigation with 300 mm of sewage water + 300 mm of ground water per annum (SW) and with 600 mm of ground water per annum (GW). Soils of the study fields were Typic Ustochripts with sandy to loamy sand texture. The concentrations of all elements except As increased following the addition of leather complex effluents in the sewage water, with the biggest increase in the concentration of Cr (from 2.7 mg to 14.0 mg Cr L−1). The SW treatment increased concentrations of all elements in ...
TL;DR: The present study shows that the waters are oversaturated with respect to calcium Carbonate, that no equilibrium conditions exist and that phosphorus removal has led to undetectable changes in calcium carbonate oversaturation, and it is concluded that the primary changes in phosphorus levels within the river is directly associated with changing point source contributions from the STW and physical dilution within the River Kennet.
TL;DR: In this paper, a horizontal flow constructed wetland at the University of Dar es Salaam was commissioned for treatment of wastewater effluent from the University waste stabilization ponds (WSP).
TL;DR: The MBR demonstrated the highest efficacy towards grey water recycling in terms of the three main water quality determinants of CBOD5, turbidity and total coliforms, providing 100% compliance in all cases.
Patent•
21 Apr 2000TL;DR: In this paper, an anaerobic digester is used to break down the fats, oils, and greases, proteinaceous, and carbonaceous substances contained in the byproducts.
Abstract: A system and method for converting animal, vegetable, and food byproduct materials into useful bio-gas and fertilizer, and/or soil amendment products has an anaerobic digester, a liquid-solids separating unit, an ammonia stripper, an ammonia absorption unit, a solids processing unit, and an equilization tank. The system and method use anaerobic digestion to break down the fats, oils, and greases, proteinaceous, and carbonaceous substances contained in the byproducts. Anaerobic digestion creates bio-gas, mainly methane and carbon dioxide, waste biosolids, which can contain phosphorous, nitrogen and other trace minerals, and a liquid effluent with significant ammonia levels. Ammonia, a useful ingredient for fertilizer formulation, is recovered from the effluent. The solids and the extracted ammonia and/or phosphorous can also be used to make fertilizer and/or soil amendment materials. The bio-gas can be used to fuel various energy recovery devices, such as boilers for steam generation, gas engine generator systems for power generation.
TL;DR: In this paper, the effect of cyanide on the anaerobic treatment of synthetic wastewater, containing starch and volatile fatty acids, was evaluated, and the results demonstrated the potential of anaerobatic treatment for COD removal in contaminated waste waters.
TL;DR: Overall, the relative performance of the beds was similar, but some significant differences were found, and bacterial removal efficiency was strongly, negatively correlated with the flow rate of effluent through the system and, at times of high flow, beds were often relatively inefficient in removing both indicator organisms.
Patent•
30 Sep 2000
TL;DR: In this article, a method and system for treating wastewater in an onboard ship sewage treatment system having controlled suspended solids, the method comprising the steps of collecting wastewater in a collection tank and transferring the wastewater to a bioreactor to oxidize organic material contained in the wastewater by adding oxygen-containing gas thereto.
Abstract: A method and system for treating wastewater in an onboard ship sewage treatment system having controlled suspended solids, the method comprising the steps of collecting wastewater in a collection tank and transferring the wastewater to a bioreactor to oxidize organic material contained in the wastewater by adding oxygen-containing gas thereto. The bioreactor is operated to provide a mixed liquor having a solids concentration of at least 5 g/l and the solids concentration is continuously increased in the mixed liquor in the bioreactor to not greater than 30 g/l. When the solids concentration in the mixed liquor reaches at least 15 g/l, a portion of the mixed liquor is removed from the bioreactor. Thereafter, wastewater is added to the bioreactor to decrease the solids concentration of remaining or residual mixed liquor to not less than 5 g/l. The bioreactor is further operated to increase the solids content again. A hollow fiber membrane is used to remove water from the mixed liquor to provide treated effluent.
TL;DR: The chemical composition, molecular weight distribution, and biodegradability of soluble microbial products (SMPs) in an anaerobic baffled reactor (ABR) treating low-strength wastewater were investigated in this paper.
Abstract: The chemical composition, molecular weight (MW) distribution, and biodegradability (both aerobic and anaerobic) of soluble microbial products (SMPs) in an anaerobic baffled reactor (ABR) treating low-strength wastewater were investigated. The effect of various process parameters on the production of SMPs was also examined. Results indicated that high MW (>300 kDa) compounds were produced in the middle compartments of the reactor and formed 22% of the effluent chemical oxygen demand (COD). This fraction was found to be 86% degradable under aerobic conditions but only 4% under anaerobic conditions. Low MW (<1 kDa) material represented the highest portion (36%) of the effluent COD and was mainly found in the first compartment of the ABR and in the effluent. This fraction was more easily degraded under anaerobic conditions (33%) than aerobic conditions (17%). Analysis of a hydrolyzed sample of the high MW fraction revealed the presence of several sugars and volatile fatty acids. Therefore, it was concluded that the high MW material contains heteropolysaccharides. Nuclear magnetic resonance analysis of the low MW fraction revealed the possible presence of alcohol, carboxylate, and aromatic chemical groups. SMP production increased with increasing hydraulic retention time (HRT), probably due to enhanced biomass decay at high HRTs, and also increased with decreasing temperature, probably due to increased stress on the biomass and a reduced metabolism of the SMP at low temperatures. Finally, SMP production in an ABR containing higher levels of initial biomass concentration was greater than for an ABR operating at the same conditions but with lower levels of initial biomass.