Showing papers on "Effluent published in 1990"

Oxygen Transport through Aquatic Macrophytes: The Role in Wastewater Treatment

Abstract: Laboratory experiments were conducted to determine the effectiveness of three floating and six emergent aquatic macrophytes in improving domestic wastewater quality, based on their capacities for O₂ transport into the effluent Oxygen transport into the rooting zone of the plants created an oxidized microenvironment, thereby stimulating C and N transformations critical to wastewater treatment Plants were cultured in flasks containing deoxygenated primary and secondary sewage effluent for an 8-d period Oxygen transport by the plants was measured in terms of both O₂ consumed by the effluent (biological O₂ demand reduction—BOD₅) and increased effluent dissolved O₂ Two floating plants, pennywort (Hydrocotyle umbellata L) and waterhyacinth [Eichhornia crassipes (Mart) Solms], and the emergent plants pickerelweed (Pontederia cordata L) and common arrowhead (Sagittaria latifolia L), were superior in improving primary sewage effluent quality, by reducing BOD₅ up to 88%, NH₄-N up to 77%, and increasing dissolved O₂ up to 61 mg L⁻¹ Nitrification rates in pennywort- and water hyacinth-based water treatment systems were calculated to be in the range of 12 to 47 kg NH₄-N ha⁻¹ d⁻¹ Oxygen transport through plants accounted for up to 90% of the total O₂ transported into the effluent In separate batch experiments, the effectiveness of diffuse mechanical aeration (5 and 50 mL air min⁻¹) and of biological aeration (O₂ transport by selected plants including pennywort, waterhyacinth, pickerelweed, and common arrowhead) on the rate of contaminant removal from deoxygenated primary sewage effluent were compared for a 26-d period Biological and mechanical aeration effected similar BOD₅ removal First-order reaction rate constants for BOD₅ removal were from 00066 to 00079 h⁻¹ and from 00041 to 00051 h⁻¹ for biological and mechanical aeration, respectively Rate constants for NH₄-N removal were from 00024 to 00107 h⁻¹ for the plant treatments Virtually complete BOD₅ removal occurred in biological and mechanical aeration treatments within 20 d Complete nitrification of NH₄-N had occurred within 12 d after mechanical aeration was initiated, but subsequent N-loss by denitrification was inhibited In the biological aeration treatments, negligible effluent (NO₃ + NO₂)-N levels were measured, but 65 to 100% NH₄-N loss occurred both by plant assimilation and by sequential nitrification-denitrification reactions Florida Agric Exp Stn Journal Series R-00084

Ammonium uptake using Ulva (Chlorophyta) in intensive fishpond systems: mass culture and treatment of effluent

Abstract: A vegetative clone ofUlva lactuca L. was selected for mass culture and nutrient uptake experiments with fish pond wastewater. Growth rates of over 55 g dry wt. d−1 per 6001(1 m2) tank were obtained. Growth rate was linked to stocking density, tank flushing rates and aeration induced thallus movement. The plants could not survive on the macronutrients provided by a weekly pulse of wastewater. A continuous supply of fish pond wastewater was required to maintain good growth rates. An ‘uncoupling’ of growth rate and thallus nitrogen content was observed. The plants were able to store nitrogen from a pulsed ammonium supply and allot the nitrogen reserves to new tissue growth. Plants with slower growth rates or a continuous supply of ammonium had higher thallus nitrogen content.Ulva efficiently removed up to 85% of the ammonium from fish pond wastewater in darkness or light independently of temperature fluctuations.

Assessment of the bacteriological activity associated with granular activated carbon treatment of drinking water.

Abstract: Bacteriological analyses were performed on the effluent from a conventional water treatment pilot plant in which granular activated carbon (GAC) had been used as the final process to assess the impact of GAC on the microbial quality of the water produced. Samples were collected twice weekly for 160 days from the effluents of six GAC columns, each of which used one of four different empty-bed contact times (7.5, 15, 30, and 60 min). The samples were analyzed for heterotrophic plate counts and total coliforms. Effluent samples were also exposed to chloramines and free chlorine for 60 min (pH 8.2, 23 degrees C). Bacterial identifications were performed on the disinfected and nondisinfected effluents. Additional studies were conducted to assess the bacteriological activity associated with released GAC particles. The results indicated that heterotrophic plate counts in the effluents from all columns increased to 10(5) CFU/ml within 5 days and subsequently stabilized at 10(4) CFU/ml. The heterotrophic plate counts did not differ at different empty-bed contact times. Coliforms (identified as Enterobacter spp.) were recovered from the nondisinfected effluent on only two occasions. The disinfection results indicated that 1.5 mg of chloramines per liter inactivated approximately 50% more bacteria than did 1.0 mg of free chlorine per liter after 1 h of contact time. Chloramines and chlorine selected for the development of different bacterial species--Pseudomonas spp. and Flavobacterium spp., respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Monitoring linear alkyl benzene sulfonate in the environment: 1973–1986

Abstract: Results from extensive monitoring from 1973 to 1986 indicate that linear alkyl benzene sulfonate (LAS) is extensively removed by sewage treatment with resulting river water concentrations in the low ppb range. Wastewater treatment plant removal efficiencies exceed those for biochemical oxygen demand (BOD); they average 98% for activated sludge, 80% for trickling filters and 27% for primary clarification. Concentrations in influent sewage (x = 3.5 mg/L), effluent sewage (x = 0.06–2.1 mg/L), and in river waters (<0.005–0.3 mg/L) are in agreement with predicted concentrations and measurements by other investigators. Levels of LAS in soil cores analyzed shortly after sludge amendment range from <3 to 47 mg/kg and are consistent with sludge loading rates and biodegradation of LAS from the previous year's sludge application. Removal of LAS occurs by biodegradation in all compartments and sorption/settling from the water column. Longer chain length, more sorptive LAS homologs are relatively enriched in sludge solids and in river sediments, thus the average LAS chain length was found to be higher in those compartments. Results obtained from long-term monitoring support the rapid removal of LAS by biodegradation in the environment.

Reduction of toxic chromate in an industrial effluent by use of a chromate-reducing strain of Enterobacter cloacae.

Abstract: Detoxification and removal of hexavalent chromium (chromate: CrO4 2−) in an industrial effluent was investigated using Enterobacter cloacae HO1. This bacterium could completely reduce chromate to less toxic trivalent chromium when appropiate nutrients were supplied to the effluent. The reduction rate was strongly dependent on the amount of added carbon and energy sources, and also on cell density. Since the reduced chromium readily formed insoluble chromium hydroxides, about 40% of the reduced chromium could be removed from the treated water by centrifugation.

Irrigation of turfgrass with secondary sewage effluent. I, Soil and leachate water quality

Abstract: (...) The objective of this field experiment was to evaluate the effect of secondary treated municipal effluent irrigation on soil and leachate properties under a turf groundcover during the first 16 mo of irrigation. Research plots were irrigated identically with either effluent or potable water using a leaching fraction of approximately 20%. Effluent irrigation resulted in significant changes in soil properties after a relatively short period of time (...)

Process for removing water soluble organic compounds from produced water

Abstract: A process for the removal of water soluble organic compounds from produced water is provided. The process allows for the removal of water soluble organic compounds by passing the produced water through a column of adsorbing resin which is capable of removing the soluble organic compounds from the water and providing an environmentally acceptable effluent. The process further allows for the regeneration of the adsorbing resin by backwashing the resin with a solvent capable of eluting accumulated soluble organic compounds from the column. The process further allows for the treatment of the eluting solvent and soluble organic compound admixture in a manner to allow reuse of the solvent and to allow recovery of the soluble organic compounds or to allow direct injection of the soluble organic compound admixture into the oil stream. Thus, the invention provides a process for removal and recovery of water soluble organic compounds from produced water which creates no environmentally hazardous waste streams.

Long-term Monitoring of the Effects of Treated Sewage Effluent on the Intertidal Macroalgal Community Near Cape Schanck, Victoria, Australia

Abstract: The purpose of this paper is to document the long-term temporal and spatial variations of intertidal macroalgae on rocky reefs near the sewage effluent outfall. Various community and population parameters are utilised to determine the impact of the effluent on the macroalgae over an eight year period up to July 1988

Large‐scale anaerobic/aerobic treatment of complex industrial wastewater using immobilized biomass in fluidized bed and air‐lift suspension reactors

Abstract: Results are presented on pilot and full-scale pretreatment of industrial wastewater in an anaerobic 2-stage fluidized bed reactor for CH 4 -production and laboratory and pilot scale post-treatment of the anaerobic effluent, which contains NH 4 + and HS − in an aerobic air-lift suspension reactor for the production of NO 3 − and SO 4 2−

Wastewater Treatment by Immobilized Cells

Abstract: Physico-Chemical Aspects of Cell Adsorption. Adsorption and Attachment of Microorganisms to Solid Support. Entrapment of Microbial Cells for Wastewater Treatment. The Morphology and Electron Microscopy of Microbial Aggregates. Application of Biomass Carrier in Activated Sludge Process. Effluent Treatment With Immobilized Microalgae and Cyanobacteria. Immobilized Cell Systems in Anaerobic Digestion Process. Biological Process in Toxic Waste Treatment. Fundamentals and Advances in Expanded Bed Reactors for Wastewater Treatment. Fluidized Bed Reactor in Wastewater Treatment.

Aerobic wastewater treatment with alkalinity control

Abstract: Aerobic wastewater treatment processes are controlled utilizing alkalinity measurements. A base line of alkalinity is determined by measuring the alkalinity profile of the influent to the aerobic wastewater treatment process. The alkalinity of the wastewater is sensed at a number of different points in the aerobic wastewater treatment process, such as at a clarifier effluent and sludge exit, aeration zone, and aerobic digester effluent. When the sensed alkalinity at any given point is above a predetermined amount over base line alkalinity, the air supply is increased and/or the concentration of microbes and food is reduced (as by increasing the sludge withdrawal rate from a clarifier) until the sensed alkaline level is stabilized. When the sensed alkalinity is below a predetermined amount under base line, the air supply is decreased and/or the concentration of feed and microbes increased (as by reducing or terminating sludge withdrawal from a clarifier) until the sensed alkalinity level is stabilized. Anaerobic odors are eliminated, plant operation and efficiency is improved, settling is improved, there is enhanced removal from the secondary clarifier, and solids carryover is reduced increasing the quality of effluent from the clarifier.

Correlation between environmental monitoring of thermophilic campylobacters in sewage effluent and the incidence of Campylobacter infection in the community.

Abstract: Environmental monitoring of thermophilic campylobacters in liquid sewage effluent (primary settlement only) during 1988 and 1989 showed a prominent seasonablity with distinct peaks in May and June (the average number of bacteria per 100 ml of effluent in months other than May and June was 2244 and the average for the peak months was 50 778). Apart from September 1989, this seasonality coincided precisely with the seasonal variation of Campylobacter enteritis in the community with similar distinct peaks in May and June (the incidence of infection in May and June was twice or three times that in the other months). Sampling of sewers showed that the campylobacters in the sewage effluent came mainly from abbatoir and animal processing plants with only a minor input from the community. Therefore, the seasonal peaks in the sewage effluent and in the community may not be dependent on human infections but on zoonotic infections which may also peak in May and June.

The use of phytotoxicity tests (common duckweed, cabbage, and millet) for determining effluent toxicity.

Abstract: The objective of this study was to use higher plants for detecting effluent toxicity. Eight effluent samples were obtained from three industrial sources prior to their entry into a sewer system. The tests were the duckweed reproduction test, and root growth tests using cabbage and millet. The results of repeated phytotoxicity tests were reproducible. Of the three industrial sources, the effluent samples from a specialty chemical industry were the most toxic. For two samples from this source, the IC50 values (the concentrations which caused 50% inhibitory effect) for duckweed were less than 1.6% effluent concentration. The samples from an agricultural product utilization plant were the least toxic. For these samples, root growth tests failed to obtain IC50 values while the duckweed tests showed IC50 values of 91 and 43% effluent concentration. Among the three types of tests conducted, the duckweed reproduction test showed the greatest sensitivity to effluent toxicity, while root growth tests using cabbage and millet had mixed results. Duckweed is recommended as a part of a battery of tests for effluent toxicity.

Process and apparatus for a biological reactor to purify water

Abstract: A system and method to remove pathogenic organisms and other suspended and dissolved containments from sewage or other contaminated water by an inexpensive, nearly maintenance free device. Principles of operation include new effective methods whioch combine synergistically, suspended and fixed film biological reactor, settling chamber, physical filter, and composting technology, to achieve tertiary sewage treatment and equivalent treatment of other contaminated water without outside energy input being required. Contaminated water flows into the apex or center of a large circular, wedge or conic chamber, then radially through precisely shaped layers of medium which provide progressive treatment by reduced pore size and increased surface area as the flow proceeds to the periphery. Oxygen can be diffused into the final treatment stage by providing large surface exposure to ambient air. The treated effluent has a benign health and aesthetic quality to permit disposal as normal surface run-off, used for irrigation and landscaping or allowed to percolate into subsurface soil without clog mat formation.

Treatment of Brewery Effluent by UASB Process

Abstract: A five-month pilot study was conducted to examine the effectiveness of the upflow anaerobic sludge blanket (UASB) process for the treatment of effluent from a brewery in rural China. Results indicate that the process operated at 26°C could reduce over 89% of chemical oxygen demand (COD) and 92% of five-day biochemical oxygen demand (BOD\d5) from the brewery effluent, with a hydraulic retention time (HRT) of 13.3 hr and a COD loading rate of 4.9 kg COD/m³/day. The brewery effluent in this study on average contained 2,692 ppm COD and 1,407 ppm BOD\d5. The treated effluent on the other hand contained 295 ppm COD and 122 ppm BOD\d5; both of which could be further reduced should the suspended solids be more effectively removed. Overall, this process was operated satisfactorily and smoothly, as reflected by the constant effluent pH and gas production rate, as well as the consistently high degrees of reduction of COD and BOD\d5. Parameters such as sludge density, distribution of volatile suspended solids (VSS) and soluble COD in sludge bed, gas production rate, and nutrient levels are discussed.

Influence of paper mill effluent irrigation on soil enzyme activities

Abstract: The practice of disposal of pulp and paper mill effluent onto the land adds large quantities of organic carbon and major essential elements to soils. In this study, it was noted that a number of such soils had high organic matter contents and increased microbial populations, which were directly proportional to the periods of effluent irrigation. The application of effluent over a period of 15 years increased both the bacterial and the fungal populations in soil. There was an increase in amylase. phosphatase and dehydrogenase activities in these soils as the period of effluent irrigation increased. The activities of cellulase and invertase were greater in submerged soils than in garden soils to which effluent had been applied.

Membrane separation process for cracked gases

Abstract: A process for recovering hydrogen from a cracking effluent wherein a cracking effluent is compressed, and then at least a portion of the hydrogen is separated from the cracking effluent prior to cooling of the cracking effluent to remove lower-boiling components. The separation of hydrogen is preferably accomplished by passing the cracking effluent through at least one semi-permeable membrane.

Irrigation of turfgrass with secondary sewage effluent: II. Turf quality.

Abstract: () This field experiment evaluated the continuous use of secondary treated municipal sewage effluent on turfgrass quality over a 64-wk period In April 1987, common bermudagrass (Cynodon dactylon L Pers) was seeded to a Sonoita gravelly sandy loam (coarse-loamy, mixed, thermic Typic Haplargid) and maintained under fairway conditions In October of that year, perennial ryegrass (Lolium perenne L) was overseeded to maintain an actively growing turf Plots were irrigated identically with either effluent or potable water Effluent irrigation led to significantly lower seed emergence but improved seed establishment ()

Impact of distillery effluent application to land on soil microflora

Abstract: A pot culture experiment was conducted to evaluate the effect of different treatments of distillery wastewater, ie raw, treated, diluted and raw distillery wastewater mixed with domestic waste stabilization pond effluent (1:1) on populations of bacteria, fungi, actinomycetes and nitrogen fixing bacteria The results indicated that raw wastewater decreased the population of bacteria, fungi and actinomycetes The growth rates of Rhizobium and Azotobacter were also reduced after raw wastewater application The toxic effect of raw wastewater was minimized when it was mixed with stabilization pond effluent (1:1), this was demonstrated by an increase in the populations of all the microorganisms studied When a groundnut plant was irrigated with raw distillery wastewater, no fruits were produced and there was also less nodulation This study indicates that raw distillery wastewater is very toxic to the soil microorganisms which are important in the soil ecosystem

Meat processing effluent treatment in surface-flow and gravel-bed constructed wastewater wetlands

Abstract: Pilot-scale surface-flow and gravel-bed constructed wetland systems were evaluated for the treatment of partially treated meat processing effluents containing high concentrations of ammonium nitrogen (>80 g/m3). Three surface-flow wetlands, each planted with four species of emergent wetland plants and receiving wastewater from different stages of treatment in a sequential pond system, were monitored for 10 months. In addition, the performance of three gravel-bed wetlands (two planted, one unplanted), receiving anaerobically treated wastewater, was monitored for 18 months. Suspended solids and COD concentrations in wetland effluents were consistently lower than those from a facultative pond treating the same effluent. Nitrogen removal by the wetlands was low (≤22%) and was probably limited by insufficient nitrification.

Influence of irrigation with pulp and paper mill effluent on soil chemical and microbiological properties

Abstract: Irrigation of sugarcane crops with combined pulp and paper mill effluent increased soil pH, organic C, N, P, and K. Over a period of 15 years effluent application increased exchangeable Na by 4.5-fold compared with control soil (well-water irrigated), which ultimately elevated the Na adsorption ratio of the soils. The combined effluent irrigation increased the soil populations of bacteria, actinomycetes, fungi, rhizobia, and yeasts. The populations of soil microorganisms were higher after 15 years of effluent treatment, followed by 3, 2, and 1 year of effluent treatment; these populations were directly proportional to soil organic C and to the available nutrient status of the soils. Regular monitoring of microflora showed a considerable change in the populations from one sampling month to another. Soil samples, including the control, collected in May (summer) showed maximum counts of bacteria, fungi, rhizobia, and yeasts.