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Showing papers on "Wastewater published in 1991"


Journal ArticleDOI
TL;DR: In this article, the design of UASB-reactors is discussed for different types of wastewater, viz. industrial soluble non-complex wastewaters, SS-rich complex wastewwaters and domestic sewage.

635 citations


Journal ArticleDOI
TL;DR: Particle size information derived from membrane separation of wastewater samples and quantification of solids and organic content is used to examine particulate contaminants in wastewater in terms of size distributions and biological treatability as mentioned in this paper.

180 citations


Journal ArticleDOI
TL;DR: The typical effluent quality that can be achieved on a long-term average is 4-10 mg/l of total nitrogen as mentioned in this paper, which is the dominating compounds in the effluent.

168 citations


Journal ArticleDOI
TL;DR: In this article, a method based on oxygen uptake measurements is introduced to characterize organic material in domestic wastewater in view of mathematical models for the activated sludge process, which allows the determination of stoichiometric as well as kinetic parameters necessary for the description of heterotrophic growth and hydrolysis of slowly degradable organic matter.

154 citations


Journal ArticleDOI
TL;DR: The behavior of selected organotin species in a wastewater treatment plant of Zurich, Switzerland, was studied in this paper, where the fraction of organotins in the particulate phase decreased with decreasing suspended solids concentration.
Abstract: THe behavior of selected organotin species in a wastewater treatment plant of Zurich, Switzerland, was studied. In untreated wastewater, monobutyltin (MBT), dibutyltin (DBT), and tributyltin (TBT) were detected in the range of 136-564, 127-1,026, and 64-217 ng/L, respectively, of which 81-92% were associated with suspended solids. During treatment, the fraction of organotins in the particulate phase decreased with decreasing suspended solids concentration. All organotin species monitored were found to be efficiently removed from wastewater, mainly by sedimentation in the primary clarifier. In the secondary effluent, levels of different organotins were in the range of 7-47 ng/L. These compounds were transferred into sewage sludge, indicating that the most important process for the elimination of organotins was adsorption into sludge. Residues of MBT, DBT, and TBT in digested sludges were in the range of 0.10-0.97, 0.41-1.24, and 0.28-1.51 mg/kg (dry weight), respectively.

153 citations



Journal ArticleDOI
TL;DR: In this article, a non-equilibrium steady state box model is reported, that predicts the fate of new chemicals in a conventional sewage treatment plant from a minimal input data set, written in an electronic spreadsheet (Lotus™ 123).

120 citations


Journal ArticleDOI
TL;DR: In this paper, an intermittent aeration process with an activated sludge unit was evaluated with typical wastewater from swine housing (total N/BOD5 ratios were 0.18, 0.31 and 0.45), in comparison with a conventional process (a conventional process, NLAP), under 0.50 kg m−3 d−1 BOD loading for each unit in bench scale.

118 citations


Journal ArticleDOI
TL;DR: Pollutant-removal efficiency of certain macrophytes and algae, such as Eichhornia crassipes, Microcystis aeruginosa, Scenedesmus falcatus, Chlorella vulgaris and Chlamydomonas mirabilis, has been tested in laboratory conditions to evaluate their potential role in wastewater treatment.

105 citations


Journal ArticleDOI
TL;DR: A laboratory scale (4 litres) UASB reactor was operated for more than a year, fed with wastewater from a cheese production industry, with an organic loading rate (Bv) of 31 g COD/litre per day ( t = 1·7 h ) and a COD reduction near to 90% were reached, operating in steady-state conditions using a wastewater with a COC influent of 2050 mg/litr (BOD 1300 mg/latre).

98 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated the effect of natural phenomena (e.g., winter storms, El Nino) on the benthos and found that the effect was greater than LACSD wastewater effects 1 km, about equal to LACDS wastewater effects 3 km, and less than the LACCS wastewater effects 5 km from the outfalls at the LCSD 1983-1986 mass emission rate.
Abstract: As pollution from the Los Angeles County Sanitation Districts (LACSD) outfalls decreased between 1980 and 1983, the macrobenthic community partially recovered and surficial (0–2 cm deep) sediment contamination and toxicity decreased at 60 m water depth along a pollution gradient from the outfalls. Pollution from the LACSD outfalls continued to decrease but macrobenthic conditions and surficial sediment quality deteriorated 1 km, was unchanged 3 km, and improved 5–15 km from the LACSD outfalls between 1983 and 1986. The net effect of natural phenomena is indicated when ecosystem changes occur in the opposite direction from that expected under prevailing pollution conditions. Our data suggest that the net effect of natural phenomena (e.g. winter storms, El Nino) on the benthos was greater than LACSD wastewater effects 1 km, about equal to LACSD wastewater effects 3 km, and less than the LACSD wastewater effects 5–15 km from the outfalls at the LACSD 1983–1986 mass emission rate. Surficial sediment samples collected beyond the 1 km station from the LACSD outfalls probably represented ⪢ 3 years of natural + effluent particulates accumulation, and they were, therefore, better suited for detecting long-term trends than for testing short-term temporal variability in surficial sediment contamination and toxicity. Nevertheless, some contaminants in the surficial sediments significantly increased between 1983 and 1986, probably primarily reflecting renewed wastewater effects near the outfalls and the effects of natural phenomena (e.g. storm-induced sediment transport or erosion) further from the outfalls. Since natural phenomena may have an effect on the benthos ≥ 3 years of LACSD wastewater effects, short-term benthic changes must be interpreted cautiously at the study site.

Journal ArticleDOI
TL;DR: In this paper, a qualitative study of the phenols present in oil-mill wastewater by thin layer chromatography has been done and quantitative determination of total phenols, ortoand meta-diphenols as well as Chemical Oxigen Demand (COD) before the treatment, after the pretreatment and after biomethanization have been carried out.
Abstract: Oil-mill wastewater is the main responsible of the pollution in Andalusian due to high content of organic substances. Its depuration by methanization is difficult because of the antimicrobial activity of phenolic derivatives. These compounds can be drastically reduced by a previous aerobic treatment of the oil mill wastewater with specific microorganisms. After this pretreatment, anaerobic depuration takes place without inhibition, the velocity of the reaction being 5 times higher than before the pretreatment. In this paper a qualitative study of the phenols present in oil-mill wastewater by thin layer chromatography has been done. Beside that, quantitative determination of total phenols, ortoand meta-diphenols as well as Chemical Oxigen Demand (COD) before the treatment, after the pretreatment and after biomethanization have been carried out. Finally, leucoanthocyanins that could originate polymerized phenols have not been found.

Journal ArticleDOI
TL;DR: In California and throughout the world the need for adequate, hygienic waste water management is ever increasing while the per capita share of the GNP allocated to this vital function is ever decreasing as discussed by the authors.

Journal ArticleDOI
TL;DR: In this paper, the possibility of phosphorus removal from wastewater by fixation with half-burned dolomite grains was investigated, and the results obtained showed the formation of a non-stochiometric calcium phosphate on the surface of the grains, undoubtedly of an amorphous nature as structure identification could not be made when X-ray diffraction techniques were employed.

Journal ArticleDOI
TL;DR: In this article, the authors discuss a variety of measures available to anaerobic treatment technologies for dealing with the limitations of paper mill waste streams, such as the presence of toxic and recalcitrant organic compounds, high concentrations of sulfur and in some cases high wastewater temperatures.

01 Jan 1991
TL;DR: In this paper, the anaerobic digestion of high strength molasses wastewater (molasses alcohol stillage and raw molasses) in a hybrid anaerobically baffled reactor was studied.
Abstract: The anaerobic digestion of high strength molasses wastewater (molasses alcohol stillage and raw molasses) in a hybrid anaerobic baffled reactor was studied. At an organic loading rate of 20 kg COD/m3-day, the reactor performed effectively achieving total and soluble COD removals in excess of 70%. Granulation of biomass was observed in the reactor and the granules grew in size with time as the experiment progressed. The predominant methanogens similar to Methanothrix and Methanosarcina species were observed in the granules. Nitrogen and phosphorous were supplemented whenever needed. Biomass retention inside the reactor was very good. Gas production was 5 v/v of the reactor·day.

Journal ArticleDOI
TL;DR: Systematic screening for dye decolorizing and/or degrading bioagents from soil and water samples discovered fungi which show dramatic color removal capability, which may be of great significance in uncovering new methods for bio-removal or bio-recovery of dye substances in wastewater.

Journal ArticleDOI
TL;DR: In this paper, the catalytic effectiveness of cobalt (II)-4,4 4,4, 4',4',4'',4' 4'', 4''4' -tetrasulfophthalocyanine (Con^(II)TSP) for hydrogen sulfide autoxidation in wastewater was investigated.
Abstract: The catalytic effectiveness of cobalt (II)-4,4’,4”,4’’’-tetrasulfophthalocyanine (Con^(II)TSP) for the autoxidation of hydrogen sulfide, S(-II), in wastewater was investigated. At pH 7 and 25 oC the rate of S(-II) oxidation is first order with respect to [S(-II)]. A fractional order on the catalyst was observed. At oxygen concentrations of 15-200 µM the oxygen dependence can be described by simple Michaelis-Menten kinetics with K = 65 µM. The uncatalyzed oxidation of sulfide by molecular oxygen was found to be faster in wastewater than in clean water. This difference was attributed to microbial oxidation of S(-II) and to catalytic action of transition metals present in wastewater.


Patent
08 May 1991
TL;DR: In this paper, an apparatus for treating waste water including a waste water basin and a number of wetland plants in floating containers adapted to float on the surface of the waste water in the basin such that the root systems of the plants treat the water.
Abstract: An apparatus for treating waste water including a waste water basin and a number of wetland plants in floating containers adapted to float on the surface of waste water in the waste water basin such that the root systems of the wetland plants treat the waste water. The floating containers are constructed so that they retain soil and/or another particulate solid required to sustain and nourish the wetland plants and also so that they permit the root systems of the wetland plants to grow outwardly into the waste water to be treated. The root systems produce aerobic zones within the waster water in the waste water basin. The extent of the growth of the root systems is controlled, preferably by an adjustable platform associated with each floating container, so that the aerobic and anaerobic zones within the waste water basin are controlled and can be adjusted or varied as required.

Journal ArticleDOI
TL;DR: The use of biomass immobilized on small suspended carriers has proven to be a suitable mean to overcome most of the problems of low growth rate of the micro-organisms, low settling rate process instability, and the need for after-treatment of the noxious anaerobic effluent.

01 Jan 1991
TL;DR: In this article, two fixed-bed reactors with loading rates of 2−18·5 g/l day and hydraulic retention times of 5 to 0·5 day were run in parallel, the biological efficiency achieved was, on average, 85−30% (bamboo as carrier) and ηCOD = 80−27% (bones as carrier).
Abstract: The experiments showed that fixed-bed reactors are suitable for the anaerobic treatment of unsettled wastewater rich in solid substances, such as slaughterhouse wastewater. Two fixed-bed reactors with loading rates of 2–18·5 g/l day and hydraulic retention times of 5 to 0·5 day were run in parallel, the biological efficiency achieved was, on average, ηCOD = 85−30% (bamboo as carrier) and ηCOD = 80−27% (bones as carrier). Even with higher loading rates methanization was stable in both reactors. The recirculation of part of the outflow can have a positive or negative influence on the reactor performance depending on the substrate concentration in the inflow. In all the comparative investigations the COD elimination rates obtained for the unsettled wastewater were below those obtained for the settled wastewater. Measurements of the fluid volume showed that a biomass enrichment in both fixed-bed reactors was completed within the first half year and that a balance had been achieved between the fixed and suspended biomass. During the entire course of the experiments both reactors were operationally reliable.

Journal ArticleDOI
TL;DR: The fungi actively excreted large amounts of laccase in the medium, and at the same time the concentration of phenolics and other toxic compounds significantly decreased, as revealed by HPLC analysis and toxicity tests on standard cultures of human cell lines.
Abstract: Four species ofPleurotus were adapted to grow on olive milling wastewater, and in certain conditions produced high yield of fruit bodies. Some biochemical transformations were observed in the olive milling wastewater owing to the growth ofPleurotus. In particular, the fungi actively excreted large amounts of laccase in the medium, and at the same time the concentration of phenolics and other toxic compounds significantly decreased, as revealed by HPLC analysis and toxicity tests on standard cultures of human cell lines.


Journal ArticleDOI
TL;DR: In this article, a kinetic study on the anaerobic digestion of olive mill wastewater (OMW) was carried out in a semicontinuous, well-stirred fermenter with microorganisms immobilized on clayey supports.

Journal ArticleDOI
TL;DR: The potential for increased risk of infectious disease to communities using reclaimed water continues to be a concern as discussed by the authors and there is an increased awareness of chemical quality with emphasis on trace organic compounds.

Journal ArticleDOI
TL;DR: In this paper, Waters, soils and plants were sampled in different sites, representing three specific irrigation sources in the Mexican Valley of Mezquital; however, few data are available for evaluating the level of heavy metal pollution in that region.
Abstract: Since the beginning of this century, wastewater has been utilized for crop production in the Mexican Valley of Mezquital; however, few data are available for evaluating the level of heavy metal pollution in that region. Waters, soils and plants were sampled in different sites, representing three specific irrigation sources in the valley. Trace metals were determined in all samples. Total amount of most trace metals in raw municipal wastewater, and that of Ni, Cr, Pb and Zn in diluted water were quite high. Wastewater irrigation markedly increased the amounts of trace elements extracted from soils by 4M HNO3; the amounts of metals were proportional to the amount of wastewater applied. Copper, chromium, and lead concentrations in soils roughly paralleled their organic matter contents. A wide range in tissue concentration of metals was observed. Zinc was the most metal absorbed by alfalfa and oats. Levels of Ni and Pb in plants, and to some extent, those of Co and Cu, were increased by raw wastewater irrigation. Chromium and lead accumulations in alfalfa were well above the tolerance levels suggested by some workers and the high Co concentration found in this legume may be a health risk for animals and human beings.

Book ChapterDOI
31 Dec 1991
TL;DR: The most recent project at the Miami Electron Beam Research Facility (EBRF) has stimulated great interest in the area of utilizing this technology for treating environmental problems as discussed by the authors, which is unique in that it is the only electron beam system set up for large scale treatment of wastewater.
Abstract: Research on the use of high energy electrons for treating water, wastewater and wastewater sludge has been under way for approximately twenty years. Much of this work has been supported by the National Science Foundation and an overview of that support has been reported on by Bryan.(1) The results of recent work, especially the most recent project at the Miami Electron Beam Research Facility (EBRF), has stimulated great interest in the area of utilizing this technology for treating environmental problems. This facility is located at the Miami Dade Central District (Virginia Key) Wastewater Treatment Plant in Miami, Florida, and is unique in that it is the only electron beam system set up for large scale treatment of wastewater.

Journal ArticleDOI
TL;DR: In this paper, a membrane extraction maw spectrometry (MEMS) technology and que was developed for the on-line analyrk of organlc components of multiple liquid and gas dreams.
Abstract: A membrane extraction maw spectrometry (MEMS) tech& que was developed for the on-line analyrk of organlc components of multiple liquid and gas dreams. Sllkone hollowfiber “branos allow for the extrcrctkn of orgalc chedcdr from compkx ad dMy matrices wtth no sampk preparrdkn. MWpk dreams of both air ad water were analyzed orrllne wlth a dngk analyzer. TM6 method has been appUed In an aerobic blologlcal wastewater treatment process. Maw balance determinations were performed by quantltatlvdy measuring HH organlc contaminants In tha lnfiumt wastewater dream, In the effluent water stream, and In the effluent air stream.

Journal ArticleDOI
TL;DR: In this article, the authors proposed a soil-aquifer treatment system for potable reuse of wastewater, which is simple and robust and offers storage of the water to absorb differences between supply and demand.