Showing papers on "Effluent published in 1986"

Oxidative degradation of aqueous phenol effluent with electrogenerated fenton''s reagent

Abstract: A novel process of an oxidative degradation of aqueous phenol effluent with hydrogen peroxide produced by electroreduction of oxygen dissolved in the effluent was studied. Effects of operational conditions such as pH, cathode potential, ferrous ion concentration and phenol concentration on the degradation rate of phenol were clarified. Phenol was successively degraded to carbon dioxide at pH 3 with higher efficiency rather than the other pH''s. The COD current efficiency at pH 3 was higher than that for the anodic oxidation process of phenol and was more than 60% for complete degradation in the range of 260-2600 ppm of initial COD.

Effects of wastewater from olive processing on seed germination and early plant growth of different vegetable species

Abstract: The effects of wastewater from olive processing on seed germination and early plant growth of different vegetable species were examined Three types of wastewater at different concentrations were tested: raw wastewater, wastewater with organic matter removed and deionized wastewater Results generally indicate an inhibitory effect on seed germination and early plant growth by all treatments containing any kind of wastewater Of the three types of effluent, raw wastewater had the greatest depressive effect, followed by deionized wastewater and finally effluent with organic matter removed Barley showed the least sensitivity to phytotoxic effects while tomato was the plant most affected The remaining vegetable species showed an intermediate sensitivity

Method for separating and recovering volatilizable contaminants from soil

Abstract: A method for separating volatilizable contaminants from soil by introducing the soil into a rotary aggregate dryer through which a working gas indirectly heated to between 750° F. and 1800° F. is drawn to vaporize the contaminants, and for recovering the contaminants for environmentally sound disposal or recycling by downstream treatment of the effluent drawn off from the dryer. The downstream treatment includes cooling the effluent to condense and precipitate out a substantial portion of the contaminants and passing the effluent through activated carbon.

Biological treatment of a landfill leachate in sequencing batch reactors

Abstract: A landfill leachate is treated, after mixing with chemical manufacturing wastewaters, by activated carbon adsorption. Biotreatment of the combined wastewater in sequencing batch reactors (SBRs) reduced the carbon requirement by 90%. Excellent treatment efficiency was consistently achieved under a variety of operating conditions: wastewater TOC, feed rate, hydraulic retention time, MLSS, organic loading, temperature, and cycle time. The SBR performance was unaffected when wastewater feeding was suspended during weekends and holidays. Results obtained in 1-L SBRs were reproduced in 12-L and 500-L units. The experimental data served as the basis for design of a full-scale SBR-adsorption system. The integrated wastewater treatment system would produce a better quality effluent at a lower overall cost. Biodegradation rates for some of the more persistent wastewater constituents were enhanced in batch bioreactors which were supplemented with strains of bacteria isolated from the landfill site.

Land application of municipal sewage sludge

Abstract: TREATMENT of municipal wastewater prior to discharge of relatively clean effluent involves a variety of processes designed to remove contaminants and pollutants. The residual material captured in the wastewater treatment process is a dilute suspension of solids called sludge. Sludge from municipal sewage consists mainly of biodegradable organic matter with significant amounts of inorganic materials. Because measurable quantities of heavy metals, toxic organic compounds, and pathogens (disease-causing microorganisms) are invariably present, disposal of sludge in an economically and environmentally acceptable manner is one of society's greatest challenges. Moreover, the sludge disposal problem continues to increase as treatment plants upgrade existing facilities to meet strict effluent discharge requirements. Most municipal sludge is now disposed of by land application, incineration, landfilling, ocean disposal, or lagooning. Land application, which is the controlled spreading of sewage sludge into or onto the soil surface, is becoming more popular as a sludge disposal option. According to the U.S. Environmental Protection Agency, land application accounted for disposal of 42 percent, by volume, of the municipal sludge generated nationwide in 1981 (8). This figure was up from 26 percent just five years earlier. Sludge is being applied to cropland, turfgrass, forests, and drastically disturbed land …

Sewage treatment method

Abstract: A method of treating sewage is disclosed that is particularly suitable for one or a small group of residential dwellings in environmentally sensitive areas. The raw sewage is flowed first into an aerobic first cell where it is aerated and forced into a highly aerobic condition where aerobic bacteria grow and consume phosphorus in a vigorous life cycle and then die. Substantial primary unloading of B.O.D., T.S.S., coliform, and phosphorous is accomplished in this first cell. The fluid from the first cell overflows into a second cell where additional sedimentary clarification occurs and it goes anaerobic. A third cell has an upwelling flow through a porous medium substrate where anaerobic bacteria converts nitrogen in nitrates and nitrites to nitrogen gas, and the fluid then flows into a fourth holding cell. The effluent in the holding cell can then be flowed intermittently through a sand filter that has a bed of dolemite for final removal of residual phosphorus before it flows into a drain field. Alum and methanol can be added to the raw sewage to, respectively, enhance initial flocculation and sedimentation in the first cell and to support anaerobic bacteria in the third cell.

Predominant bacterial genera in granular activated carbon water treatment systems.

Abstract: Granular activated carbon (GAC) beds may be used for removal of dissolved organic matter during the treatment of drinking water. However, they might also change the microbiological quality of the water entering the distribution system either by changing the predominant bacteria or the bacterial density of the treated water. A 3-year pilot plant study of water treatment using GAC beds was conducted at the Baxter Water Treatment Plant in Philadelphia. During the study, bacteria were isolated from the raw water and from the effluents of the GAC treatment units. At the end of the study, bacteria were also isolated from the GAC units and from sand beds operated in parallel with the GAC units. Bacterial genera in the GAC effluents and in the GAC units themselves were similar to those found in the raw water and in the sand beds. Prechlorination and (or) preozonation of the water before GAC treatment had no noticeable effect on the bacterial genera found as compared with GAC unit having no predisinfection. The bacterial genera found in this study were similar to those found in seven other studies of GAC water treatment that used a variety of treatment schemes and a variety of heterotrophic plate count techniques to evaluate bacterial populations. From these several studies it appears that GAC treatment does not change the nature of the bacterial populations associated with drinking water.

Aquatic Plants and Wastewater Treatment (an Overview)

Abstract: The technology for using water hyacinth to upgrade domestic sewage effluent from lagoons and other wastewater treatment facilities to secondary and advanced secondary standards has been sufficiently developed to be used where the climate is warm year round. The technology of using emergent plants such as bulrush combined with duckweed is also sufficiently developed to make this a viable wastewater treatment alternative. This system is suited for both temperate and semi-tropical areas found throughout most of the U.S. The newest technology in artificial marsh wastewater treatment involves the use of emergent plant roots in conjunction with high surface area rock filters. Smaller land areas are required for these systems because of the increased concentration of microorganisms associated with the rock and plant root surfaces. Approximately 75 percent less land area is required for the plant-rock system than is required for a strict artificial wetland to achieve the same level of treatment.

Treatment Optimization of Municipal Wastewater and Reuse for Regional Irrigation

Abstract: Municipal wastewater warrants increased attention as a potential environmental pollution and a possible irrigation water source. Under certain conditions, use of municipal effluent (treated wastewater) for irrigation is an effective means for wastewater removal. Using wastewater for irrigation of certain crops (Table 11.1) allows a less stringent treatment level in comparison to disposing of the wastewater to lakes and rivers to be utilized later and may thus alleviate environmental problems. It also has the advantages of providing extra water for farmers who may use the wastewater.

Effect of Slaughterhouse Effluent and Water Irrigation upon Aggregation in Seasonally Dry New Zealand Soil under Pasture

Abstract: Studies of the long-term (>25 years) treatment of a silt loam soil under pasture with slaughterhouse effluent showed that effluent did not affect macroaggregate stabilities as measured by wet-sieving, but increased the stability of clay aggregation as measured after selective disaggregation treatments. Highly humified organic matter was associated with the soil clays as a result of slaughterhouse effluent treatment. Studies of the similarly long-term irrigation of the same soil type with water showed that water decreased the stabilities of macroaggregates as long as they were kept wet, but increased their stabilities after air-drying. Scanning electron microscopy showed a web that became firmly bound to soils only after drying. Stabilities of aggregated clays were largely unchanged by water irrigation, though their sensitivity to the removal of polysaccharides and organically bound cations was increased by this treatment. Changes in stabilities could not be related to earthworm numbers or to the extent of mycorrhizal infection. Macroaggregate stabilities did not reflect obvious visual changes that occurred to the soil structure upon a major change in composition of the effluent. The effects of seasonal drying processes were very likely obscured by the stabilising effects of air-drying prior to wet sieving analyses for macroaggregate stabilities.

Process for purification of effluent

Abstract: A process for the purification of effluent, in which the effluent to be purified is first introduced into a high-loaded activation stage operated as an adsorption stage, then is passed through an intermediate clarifier with sludge offtake and subsequently introduced into a low-loaded stage to which a final clarification stage with sludge offtake is connected. Microorganisms work in the adsorption stage. The sludge is maintained in the initiation phase by means of the sludge takeoff from the intermediate clarification stage. Nitrification and subsequently denitrification can be carried out in the low-loaded stage. Sludge from the intermediate clarification stage can be reintroduced as recycled sludge into the adsorption stage, and sludge from the final clarification stage can be re-introduced as recycled sludge into the low-loaded stage. Also excess sludge is drawn off and thickened. The effluent is first treated in the adsorption stage under optionally-anaerobic conditions and before it flows out into the intermediate clarification stage is treated under aerobic conditions. The turbid water from sludge thickening and sludge de-watering is treated with precipitating agents before it is re-conveyed to the inflow of the filter plant.

System and method for treating pulp and paper mill waste water

Abstract: A system and method for converting pulp and paper mill waste water into a decolored, neutral pH effluent and a solid suitable for use as fuel in a furnace. The treatment system is used following primary and secondary treatment of pulp and paper mill waste waters typically found in the industry. After secondary biological treatment, the waste waters are pumped to a coagulation tank where the waste water is brought in contact with a polyamine coagulant which coagulates lignins, degraded sugars, and other compounds which typically discolor this water. The coagulation particles are increased in size by addition of an acrylamide polymer in a flocculation tank to improve the hydrophilic characteristics of the coagulant. The waste water is then mixed a dissolved air and water solution under pressure. Upon dissolution of the dissolved air at atmospheric pressure the air is absorbed by the flocculated matter in the aeration tank and the flocculated matter is caused to migrate towards the area of less pressure, i.e. the surface of the tank. The flocculated matter accumulates on the surface of the flocculating tank and can be skimmed from the top, dried and ultimately burned in a furnace.

Use of the Clyde Estuary and Firth for the disposal of effluents

Abstract: The effluents from about half of Scotland's population and industry drain to the Clyde Estuary and Firth, where they cause a number of problems of contamination and pollution. This paper outlines historical aspects of urban growth, effluent production and disposal, pollution and pollution control. The sources, nature, quantities and main effects of effluents discharged are described, as is recent national and international legislation intended to prevent or control pollution. Reference is also made to the determination of licence conditions for effluent discharges by means of the Environmental Quality Objective/Environmental Quality Standard approach.

Nematodes, including a new record of Tobrilus diversipapillatus in Australia, as potential indicators of sewage effluent pollution

Abstract: Nine nematode taxa were collected during a study of the effects of sewage effluent on benthic macroinvertebrates in Bulimba Creek, Brisbane. The nematode, T. diversipapillatus, previously unknown from Australia, comprised 80% of the collection, and was most abundant at polluted sites with high biological oxygen demand and high levels of total organic carbon. Free-living adult and juvenile Mermithidae made up 15.6% of the collection and were most abundant at sites with low biological oxygen demand. The potential of T. diversipapillatus and Mermithidae to serve as biological indicators of organic enrichment and toxic pollution is discussed in terms of these preliminary findings and literature data.

Process for the production of synthesis gas

Abstract: Synthesis gas having a stoichiometric composition desirable for subsequent conversion into methanol or Fischer-Tropsch products from a substantially sulphur-free gaseous hydrocarbon feedstock is produced by the steps of: (I) feeding substantially sulphur-free hydrocarbon-containing gas 7, steam from boiler 18 and carbon dioxide 10 to a single primary reforming zone 8 comprised of an exchanger reactor containing a steam reforming catalyst under reforming conditions wherein hydrocarbon gas is partially reformed to produce a primary reformer effluent 11, (II) feeding substantially sulphur-free hydrocarbon-containing gas 13, oxygen-containing gas 15, steam from boiler 18, carbon dioxide 9 and primary reformer effluent 11 to a secondary reformer 12 containing reforming catalyst under reforming conditions wherein hydrocarbon gas is reformed to produce a secondary reformer effluent, (III) passing secondary reformer effluent 16 from step (II) to the primary reforming zone as indirect heating medium for the exchange reactor, (IV) removing the secondary reforming effluent 17 from the primary reforming zone. Preferably carbon dioxide is removed wholly or partially from the secondary reformer effluent and recycled in a further step, step (V), as feed to steps (I) and (II) of the process.

Mercury pollution of effluent, air, and soil near a battery factory in tanzania*

Abstract: Effluent, air, and soil samples near a battery factory in Dar es Salaam, Tanzania, where HgCl2 is used to prevent mold growth, were collected to explore the potential for pollution of the environment from industrial discharge of Hg. Flameless atomic absorption spectrophotometry was used for Hg determinations. The concentration of Hg in the effluent ranged from <0.2 to 5.2 mg L−1 and the Hg concentration varied greatly within and among sampling days, showing different peaks. Air contained a mean of 4.0 μg m−3 with little variation within and between sampling days. Soils near the factory contained high Hg levels, from 6.7 to 472 mg kg−1 in the immediate vicinity, the highest level being associated with disposal of solid waste (defective batteries). Downwind the concentration of Hg decreased with increasing distance from the factory resulting in a soil concentration of 1.0 mg Hg kg−1 about 2 km away. Upwind the Hg concentration decreased drastically within a distance of 100 to 200 m.

Trace organics in septic tank effluent

Abstract: This paper reviews the available information and presents the results of a study undertaken to estimate the presence and level of certain trace organics in wastewater samples collected from a septic tank in an individual household, from a lift station, and from a waste treatment lagoon near Regina, Canada. Out of 11 priority pollutants analyzed, 6 priority pollutants — chloroform, bromodichloromethane, toluene, benzene, methylene chloride and tetrachloroethylene — were detected in the samples. Benzene and bromodichloromethane were dominant. Methylene chloride and tetrachloroethylene could not be quantified at the low concentrations present. Chloroform was present in the lagoon effluent sample once at a concentration of 0.03 μg L−1. Toluene was not present either in the septic tank effluent or in the lagoon effluent. Benzene was present in the septic tank effluent (max. value 450 μg L−1) and in the lagoon effluent (max. value 120 μg L−1). Bromodichloromethane was present in the septic tank effluent and lagoon effluent at concentrations lower than 1.10 μg L−1. The trace organics in the septic tank effluent and lagoon effluent at these comparatively low concentrations may not pose any significant risk either to aquatic life or to public health, taking into account the attentuation capacity of the soil and the dilution usually available.

Waste water clarification

Abstract: A process for increasing the efficiency of a primary clarifier in raw waste water clarification by reducing biological oxygen demand and suspended solids by the sequential addition upstream of the primary clarifier of: (1) a salt of a water soluble bi- or tri-valent metal and compositions or mixtures thereof, (2) fly-ash, and (3) a cationic surface active polymer composition comprising a branched, high cationic charge density containing and water soluble polymeric polyether amine solution at the primary clarifier and recovering the clarified effluent from the primary clarifier.