Showing papers on "Effluent published in 1981"

Method for treating wastewater using microorganisms and vascular aquatic plants

Abstract: A method for treating wastewater comprising the steps of subjecting the wastewater to an anaerobic settling step for at least 6 hours and passing the liquid effluent from the anaerobic settling step through a filter cell in an upflow manner, wherein the effluent is subjected first to the action of anaerobic and facultative microorganisms and then to the action of aerobic microorganisms and the roots of at least one vascular aquatic plant.

Anaerobic activated carbon filter for the treatment of phenol-bearing wastewater

Abstract: An experiment using an activated carbon filter for the treatment of phenol-bearing wasterwater from coal gasification processes is discussed. Two granular-activated-carbon-packed anaerobic filter systems were constructed for use in the study. Both phenol and glucose of phenol-fed reactor systems were operated under continuous feeding for a period of 735 days. The glucose-fed reactor was very effective in reducing the organic content of the feed substrate. The performance of the phenol-fed reactor was tested at three different phenol concentration levels: (1) 200 mg/l; (2) 400 mg/l; and (3) 1000 mg/l. Using the 200 mg/l concentration of phenol an average 79% of the feed chemical oxygen demand (COD) was accounted for in the aqueous and gaseous phases of the final effluent. Using 400 mg/l the COD accounted for the aqueous and gaseous phases of the effluent rose to an average of 92%, and using 1000 mg/l, the COD removal efficiencies from the three columns fell to an average of 90%, respectively. Despite the differences in removal efficiencies between the different phases of the experiment, the granular-activated-carbon-packed anaerobic bioreactor proved to be an effective process in the reduction of phenol from a synthetically prepared wastewater. In addition to phenol reduction, there was alsomore » a consistent and effective reduction of the chemical oxygen demand and the total organic carbon content of the waste at a time when a methane-rich gaseous by-product was being produced simultaneously.« less

Effects of activated carbon and bacteriostatic filters on microbiological quality of drinking water.

Abstract: Three activated carbon filters for point-of-use water treatment were tested in laboratory and field studies for chemical removal and microbiological effects on water. All removed free available chlorine in municipally treated water to below the limit of detection, but removed only about 50 to 70% of the total available chlorine and 4 to 33% of the total organic carbon. Standard plate count bacteria in the effluent increased steadily with time for 3 weeks and remained elevated over the 8-week period of the study. Total coliform bacteria were found to persist and proliferate on the filters for several days after transient contamination of the influent water. Silver-containing activated carbon filters suppressed total coliform but not total bacterial growth. Pseudomonas aeruginosa was recovered from the effluents of all filters at some time during the tests.

Human and animal salmonellosis in Scotland associated with environmental contamination, 1973-79

Abstract: Twenty-six incidents of salmonellosis occurring in Scotland between 1973 and 1979 and attributed to environmental pollution are reviewed. The apparent sources of pollution were sewage effluent (10 incidents), septic tank effluent (eight), sewage sludge (three), seagulls (three) and abattoir effluents (two). Cattle were the species predominantly affected. Human infection was primary in three incidents and was secondary to bovine infection in another four. Thirteen salmonella serotypes were recovered from infected humans or animals and 17 during related environmental investigations. The factors causing pollutions and possible control measures are discussed.

Decolorization of a kraft mill effluent with fungal mycelium immobilized in calcium alginate gel

Abstract: A white-rot fungus Coriolus versicolor was immobilized by entrapment in calcium alginate beads. Treatment of a kraft mill effluent with the immobilized fungus in the presence of sucrose resulted in 80% loss of color of the effluent within 3 days. The minimal concentration of sucrose required for the decolorization was 10 mM. Other carbon sources (xylose, glucose, glycerol, and ethanol) could also be used.

Use of Aquatic Macrophytes for Wastewater Treatment

Abstract: Wastewater treatment systems using water hyacinths have the capability of producing secondary or advanced secondary effluents. Hyacinths also have the potential for producing effluents meeting advanced waste treatment standards if optimum plant harvesting techniques and supplemental methods for additional phosphorous removal are developed. Widespread use of hyacinth systems will be confined to relatively warm climates because growth ceases at water temperatures below 50°F (10°C). Treatment facilities using duckweed could be used in colder climates, however, systems using this plant are in a very preliminary stage of development. In addition to the removal of conventional pollutants, aquatic macrophytes systems also have the capability of biologically concentrating heavy metals and synthetic organic chemicals. Preliminary cost analyses indicate water hyacinth systems could be more economical than comparable land or conventional treatment techniques.

Treatment of coal coking and coal gasification wastewaters

Abstract: Studies were conducted with heavily contaminated effluents from coal coking operations and coal gasification processes to obtain basic engineering and design data for biological waste treatment. Specific objectives were to: determine the influence of wastewater compositional characteristics on pretreatment/ identify minimum dilution requirements/ evaluate biological treatment of effluents receiving different types of pretreatment: determine biological oxidation growth constants for treatment of effluents/ determine removal efficiencies for primary effluent contaminants/ and investigate parameters that effect biological oxidation of cyanide and thiocynate. Experimental results are presented.

Waste water purification

Abstract: A novel process for the purification of waste water and/or waste water sludge comprising subjecting the waste water and/or waste water sludge to first a methane fermentation step, then a denitrification step and finally an oxidation step by aeration, the electron donor in the denitrification step being mainly the sulfide from the methane fermentation step and the remaining reduced compounds in the liquid effluent from the methane fermentation step being oxidized in the aeration step.

Persistence and distribution of pollution indicator bacteria on land used for disposal of piggery effluent.

Abstract: Numbers of pollution indicator bacteria (fecal coliforms and fecal streptococci) were assessed on land to which effluent from intensively housed pigs had been applied. Topsoil (to a 30-mm depth) was found to provide a more favorable environment for fecal coliform persistence than was pasture or subsoil. Times required for a 90% reduction in number (T90) in topsoil (calculated by linear regression of log counts obtained in a 6-week period after effluent application) ranged from 7 to 20 days (mean T90, 11 days). T90 values for fecal coliforms fell within this range irrespective of the season of application and for a number of soil types and climatic conditions. The range in die-off times was encountered irrespective of the fecal coliform count in the applied effluent or the application regimen (125 to 1,000 kg of elemental nitrogen in the form of effluent per ha; return periods, 3 to 12 months). Autumn and winter conditions were conducive to the persistence of a survivor tail of these bacteria at 10(1) to 10(3) cells per g of topsoil. Fecal streptococci survived similarly on soil and pasture (T90, ca. 14 days) and appeared slightly more suited to survival in the environment than did fecal coliforms. Contamination of subsoils after effluent applications occurred at a rate well in excess of the infiltration capacity of the soil, presumably by percolation of the effluent through soil cracks. Contamination levels of subsoils in the experimental area generally remained low.

Some effects of organic pollution on the distribution and seasonal incidence of Chironomidae in riffles in the River Cole

Abstract: SUMMARY. The effects of a sewage effluent discharge into the River Cole, Birmingham, were determined by regular collections of water and biological samples from six comparable stations, one above and five below the sewage effluent. The effluent reduced the dissolved oxygen concentration and increased the ammonia, orthophosphate and BOD concentrations in the water. The effects were much more severe during the summer. The Chironomidae were very important constituents of the benthic macroinvertebrate community at the stations downstream of the effluent. Larval densities of over 30,000 m−2 were recorded. Eleven species were common and of these Chironomus riparius was the most tolerant. There was considerable variation in the seasonal incidence of the different species. Brillia longifurca was most abundant in the spring while Cricotopus bicinctus was most abundant in the summer. Brillia longifurca, Paratrichocladius rufiventris, Prodiamesa olivacea, Micropsectra atrofasciata and Eukiefferiella claripennis had three peaks in numbers of larvae during the year. The increase in the polluted state of the river in the summer resulted in changes in the chironomid populations. Some were suppressed, e.g. E. claripennis, while C. riparius extended its range and achieved maximum abundance further downstream during the summer.

Process for desulfurizing a catalytic cracking or steam cracking effluent

Abstract: Catalytic cracking or steam cracking effluents are desulfurized without substantial decrease of their octane number by subdividing said effluent into two fractions of different boiling ranges, the heavier of which is admixed with hydrogen, the resulting mixture being completely vaporized and fed to a hydrodesulfurization zone containing a first bed of selective catalyst formed of cobalt and molybdenum, or cobalt and tungsten, or nickel and molybdenum or nickel and tungsten deposited on a non-acid carrier, and a second bed of conventional hydrodesulfurization catalyst, the effluent from the hydrodesulfurization zone being cooled down and fractionated to separate a hydrocarbon fraction of the gasoline range which is recombined with the lighter fraction of said effluent.

Method for the anaerobic degradation of organic material

Abstract: A system for the anaerobic bacterial degradation of organic material in waste water, comprising introducing the waste water into a contact reactor, pumping the Waste water into the bottom of a fluidised bed reactor containing anaerobic bacteria attached to the particles in the bed, the fluidised bed reactor having an effective volume not more than 0.35 times the effective volume of the contact reactor, returning the waste water which has passed through the fluidised bed reactor to the contact reactor and continuously or discontinuously removing treated effluent from the system. A start-up procedure for the anaerobic treatment system is described comprising culturing anoxic bacteria in the system by adding nitrate ions to the waste water and gradually reducing the amount of nitrate ions in the stream until the population of anoxic bacteria is substantially replaced by a population of anaerobic bacteria. A viable microbial population is established in both the fluidised bed reator and the contact reactor.

Efficiency of ultrafiltration for the isolation of enteric viruses and coliphages from large volumes of water in studies on wastewater reclamation

Abstract: The efficiency of a pressure ultrafiltration procedure using flat membranes for the recovery of viruses from water was evaluated. The average recovery efficiency of Escherichia coli K12 Hfr phages from 1 l samples of activated sludge effluent was 69 %, and from 10 l samples of the effluent after primary clarification in a wastewater reclamation plant 72 %, after secondary clarification 83 %, and after sand filtration 91 %. Polio 1, 2 and 3 viruses, reovirus, a rotavirus and seven different morphological types of coliphages were recovered from seeded 100 l samples of distilled, tap or reclaimed water at an average efficiency of 94 %. Apart from the high recovery efficiency, ultrafiltration has advantages over other concentration techniques in that no chemicals have to be added to water samples, viruses are not exposed to pH extremes, no secondary concentration step is required, standard equipment is available, and the method is relatively economical and simple. The filtration rate was slow but may be improved by further research. Evidence is presented that the isolation of enteric viruses by means of ultrafiltration and the detection of isolates by means of TCID50 methods using primary vervet kidney cells, is a sensitive technique for the analysis of 100 l samples of conventionally treated or directly reclaimed drinking-water.

Iodine-131 levels in sludge and treated municipal wastewaters near a large medical complex.

Abstract: Iodine-131 was found to dominate the gamma spectra of dried sludge and concentration liquid effluent samples from a sewage treatment plant serving the area containing the Texas Medical Center in 1975. The concentration of Iodine-131 varied considerably on a time scale of weeks but was fairly stable in the course of a single day. The partition of Iodine-131 between the dried sludge and the liquid effluent was found to be reasonably constant during the sampling period. Knowledge of the concentration in these phases and the daily output of sludge and effluent let to be estimate of an annual discharge of over one Curie of Iodine-131. Circumstantial evidence linking this discharge to the practice of nuclear medicine in the area is considered strong, but an attempt to correlate variation in the effluent activity with actual nuclide use was inconclusive due, among other reasons, to an insufficient clinical data base. An analysis of possible exposure pathway indicated that negligible human exposure resulted from the Iodine-131 released primarily because the receiving body of water is a saline industrial waterway. A more extensive analysis would be in order for a similar plant discharging treated wastewaters into an inland water system.

Positively charged filters for virus recovery from wastewater treatment plant effluents.

Abstract: Positively charged Zeta Plus filters were used to concentrate enteroviruses from 19 liters of effluent from activated sludge units. Neither the addition of salts nor the acidification of the effluent was required for adsorption of viruses to the filters. Viruses adsorbed to the filters were eluted by treating the filters with a solution of 4 M urea buffered at pH 9 with 0.05 M lysine. Eluted viruses were concentrated into final volumes of 1 to 2 ml by using a two-step concentration procedure that employed inorganic and organic flocculation. Approximately 50% of the viruses added to effluents could be recovered in the final sample. The procedure was used to monitor effluents from activated sludge units at two wastewater treatment plants for the presence of enteroviruses.

Estimating the Environmental Concentrations of Consumer Product Components

Abstract: Procedures are developed for estimating the environmental concentrations of chemical components contained in consumer products and disposed down the drain. The concentrations are estimated by considering the quantities ofthe chemical used in consumer products, reported values of per capita wastewater flow, the extent of removal and degradation in wastewater treatment systems, and estimates of the factors by which wastewater sludge is amended in soil and effluent is diluted in receiving streams. The stream dilution factor (the ratio of river flow rate to the effluent discharge rate) is calculated for each of 161 major river basins in the United States. The median of these values is about 100, with 91 percent of them being greater than 10. The use of these estimates in environmental risk assessments is discussed, as well as assumptions and limitations.

Irrigation of Grapevines with Sewage Effluent. I. Effects on Yield and Petiole Composition

Abstract: Five-year-old Shiraz vines established on 45 liters of sewage effluent per vine per week during the irrigation season were studied during the subsequent three growing seasons. Two additional irrigation treatments consisting of 135 liters effluent per vine per week or 135 liters of good quality reticulated reservoir (mains) water per vine per week were imposed so the effect of a greater water supply containing either a high or a low salt load could be compared. Increasing the irrigation rate resulted in a significant improvement in vine vegetative growth and yield in each of the three years irrespective of water quality. Vines irrigated with the increased allocation of water showed significant increases in berry weight, cluster weight and number, and weight of prunings. During the three seasons sodium and chloride concentrations increased in the petioles of effluent irrigated vines to concentrations greatly in excess of those in vines receiving mains water. Petioles from vines receiving 135 L of effluent contained the highest concentrations of magnesium and total nitrogen, and vines given mains water were highest in phosphorus and potassium. The concentrations measured were within the range recorded for vine petioles from other viticultural areas in southern Australia.

Effects of Chlorinated Sewage Effluents on Fish in the Sheep River, Alberta

Abstract: From bioassays with caged rainbow trout Salmo gairdneri and quantitative sampling of fish populations, the effects of a chlorinated sewage effluent on fish in the Sheep River, Alberta were determined. The data obtained contradict recent studies that indicate fish congregate below sewage outfalls but support the contention that fish avoid chlorinated effluents. However, fish moved into and out of the chlorinated effluent, presumably to forage.

Organic acid production from CO2/H2 and CO/H2 by mixed‐culture anaerobes

Abstract: The gases CO, CO2, and H2 were used as substrates in anaerobic fermentations producing organic acids. Various mixed bacterial sources were used, including sewage sludge digester effluent, rabbit feces, and soil. Nonsterile microorganism selection was carried out using CO2/H2 and CO/H2 as the primary carbon and energy sources. Cultures were grown in specially designed, high-pressure (to 70 psig) flasks. Methanogenic bacteria were eliminated from the cultures. Liquid products of the fermentations were acetic through caproic acids, with the even-numbered acids predominating. Carbon balances showed conclusively that acetic acid was formed from carbon contained in the CO or CO2 feed gas. Measurements made included rates of acid product formation, cell density, and degree of gas utilization. Limited characterization of the microorganisms was also performed. Production of organic acids by mixed culture inocula from CO2/H2 or CO/H2 had not been reported previously. Application of this work is to the production of organic chemicals from synthesis gas (SNG), produced by the gasification of fossil fuels (peat, lignite, and various ranks of coals), biomass (agricultural and forest residues, and various biomass crops grown expressly for energy recovery), and municipal solid waste. (Refs. 15).

Utilization Efficiency of Nitrogen from Sewage Effluent and Fertilizer Applied to Corn Plants Growing in a Clay Soil

Abstract: Effects of irrigation with secondary municipal sewage effluents on N availability in a fertilized soil were studied in a greenhouse experiment using ¹⁵N as a tracer. Corn (Zea mays) was grown in a clay soil with ammonium-N added as solid fertilizer, sewage effluent, and a mineral solution. Between 55 and 69% of the ammonium sulfate-¹⁵N was taken up by the corn plants. Between 21 and 32% of the fertilizer-N was recovered as organic-N in the soil after 43 days, while negligible amounts of exchangeable-NH₄ and NO₃ were detected. Losses of ammonium sulfate-N applied to the soil before seeding, probably through denitrification, ranged between 6 and 15%. Similar results were obtained whether the fertilized soil was irrigated with demineralized water, sewage effluent, or a mineral solution simulating the mineral composition of the sewage effluent. About 61% of the tagged ammonium-N applied as sewage effluent was taken up by the corn plants, and 14% was immobilized in the organic fraction of soil. About 24% of the effluent-tagged-ammonium-N was lost, apparently through both denitrification and volatilization. The corresponding loss from the mineral-solution-tagged-N was about 17%. The simultaneous application of C and N by sewage effluents was probably responsible for the increased losses of N through denitrification found in the effluent-tagged-ammonium-N treatment. Recovery of N, in plant and soil, from ammonium sulfate incorporated into the soil before planting was somewhat greater than that of sewage effluent ammonium-N, and was not affected by irrigation with sewage effluent.