Showing papers on "Effluent published in 1973"

Method for the reduction of the concentration of no in combustion effluents using ammonia

Abstract: The subject invention relates to a method for reducing the concentration of NO from combustion effluents, said method comprising the step of contacting an effluent stream containing NO contamination with a sufficient amount of ammonia in the presence of a sufficient amount of O2 and at a sufficient temperature to selectively reduce the NO from said combustion effluent.

Distribution of foraminifera near pollution sources in Chaleur Bay

Abstract: Benthonic foraminifera samples were collected seasonally near several isolated sources of sewage and (or) industrial effluent in the Restigouche estuary. Distinct biotopes based on species diversity and population density are developed locally especially near Dalhousie peninsula and Belledune Point in response to the effects of effluent discharge. Averaged diversity indices calculated in known polluted describe an initially depressed curve that reflects the development of near-abiotic conditions close to the effluent source and, at some distance offshore, an anomalously high diversity which may be indicative of a zone near each outfall in which certain components of the effluent generate a temporary favorable artificial environment. TheElphidium incertumlclavatum group usually dominates the living fauna near sewage outfalls and appears to be able to invade and maintain itself on nearshore sediment substrates which have pH values in excess of 6.4.

Efficiency of Heavy Metals Removal in Municipal Sewage Treatment Plants

Abstract: From January to July, 1972, six municipal sewage treatment plants were routinely monitored for the efficiency of heavy metals removal. The municipalities served ranged from a small agricultural community to an industrial city. Four basic plant types were studied: 1) Primary with sludge digestion; 2) Primary with sludge filtration; 3) Trickling-filter secondary with sludge digestion; and 4) Activated-sludge secondary with sludge digestion. Composite samples from the influent, effluent, and sludge were homogenized, acid-digested, and analyzed by atomic absorption spectrophotometry for Cd, Cr, Cu, Zn, and Pb. The efficiency of heavy metals removal and the relationship between heavy metals removal and suspended solids removal are discussed.

Nitrogen Transformations During Subsurface Disposal of Septic Tank Effluent in Sands: I. Soil Transformations

Abstract: Soil physical and chemical studies of five subsurface septic tank seepage beds were conducted to determine the biochemical transformations of N and thereby its potential for ground-water pollution. Effluent was found to be ponded in all the seepage beds examined due to the presence of an impeding layer, a “crust”, at the boundary between the gravel bed and adjacent soil. The crust reduced infiltration rates approximately from 500 to 8 cm/day. Soil atmospheric composition 5 cm below the crust averaged 19.6% O₂ and 0.66% CO₂. Nitrogen in the septic tank effluent occurred as NH₄-N (80%) and organic N (20%) with virtually no NO₃-N. Organic-N was largely concentrated in the crust zone. Nitrification of NH₄-N to NO₃-N was essentially complete and commenced in the unsaturated subcrust soil within about 2 cm of the crust. Nitrification did not occur and NH₄-N was absorbed by the soil below a seepage bed that was submerged in the ground water.

Occurrence of some chlorinated aliphatic hydrocarbons in the environment.

Abstract: THE total world production of chlorinated aliphatic hydrocarbons probably exceeds 3 × 106 ton yr−1 (ref. 1). Some of the compounds concerned are used chiefly as intermediates in the chemical industry (for example, in the manufacture of polyvinylchloride, aerosol propellants and refrigerants). But others are employed principally as solvents, particularly for degreasing and dry-cleaning. By contrast with the compounds used as intermediates, for which losses to the environment are unlikely to exceed 1–2%, most of those used as solvents will eventually be lost, chiefly by evaporation but also in effluents. Their loss in the United States alone has been estimated to be ∼2 × 105 ton yr−1 (ref. 2). Most of the commercially important chlorinated aliphatic hydrocarbons are comparatively stable compounds, and are likely to have reasonably long lifetimes in the atmosphere and aquatic environment. It is likely therefore that the atmosphere and surface waters would contain significant concentrations of them (particularly those used as solvents). At present there seems to be no information available about the levels of these compounds in the natural reservoirs, nor about the extent to which they are concentrated by aquatic organisms. A project has been initiated recently in these laboratories to examine the environmental distribution of the aliphatic chlorocompounds. We present here some preliminary data for air and natural waters.

The relationship between the dm content of herbage for silage making and effluent production

Abstract: A study of 16 silages made at the Hannah Research Institute and 22 silages made at the Grassland Research Institute showed highly significant positive relationships hetween the DM percentages of the material ensiled and the resultant silage. Using regression equations derived from this data, and from a record of the presence or absence of effluent, it was calculated that the average minimum DM content of herbage for ensiling which would produce no effluent was 22.9%. To ensure a margin of safety against production of effluent, a minimum DM content of 24.7% in the herbage was calculated from the confidence limits. To obtain this DM content, herhage will normally require wilting; effluent production should then be negligible.

Inorganic nitrogen removal from wastewater: effect on phytoplankton growth in coastal marine waters.

Abstract: Algal bioassays were used to demonstrate the high efficiency of a comnbined tertiary wastewater treatment and marine aquaculture system in removing inorganic nitrogen, and to show that the coastal waters off Woods Hole, Massachusetts, are limited in nitrogen for marine phytoplankton growth. When nutrients were removed from secondarily treated domestic wastewater through assimilation by phytoplankton in an outdoor growth pond, the pond effluent, in varying dilutions with seawater, could not support more phytoplankton growth than the seawater alone. However, when nitrogen was added back to the mixtures of pond effluent and seawater, the phytoplankton growth response was similar to that with a mixture of wastewater and seawater. This is similar to the findings of other researchers, and suggests that nitrogen may be the key growth-limiting nutrient in many coastal marine waters. The combined tertiary treatment-marine aquaculture system appears to be an effective means of removing nitrogen from secondarily treated wastewater and controlling eutrophication of coastal marine waters.

Field and Experimental Studies on the Effects of a power station effluent on tubificidae (Oligochaeta, Annelida)

Abstract: 1. Higher numbers of sexually mature worms of L. hoffmeisteri were found in the River Trent downstream from Drakelow Power Stations than upstream. 2. The condenser effluent from the power stations not only increased the temperature of the river but also produced a considerable increase in the concentration of dissolved oxygen. 3. Experiments were therefore carried out on the effects of these two variables on the reproductive rate of the worms. 4. In these experiments it was found that: (a) L. hoffmeisteri increased its rate of egg production with increase in temperature up to about 25°C while T. tubifex maintained a fairly steady rate of egg production over a range of temperatures from 10–25°C. (b) L. hoffmeisteri maintained a fairly steady rate of egg and cocoon production over a wide range of oxygen concentrations above 2 ppm. 5. Therefore it seems likely that the difference between the numbers of sexually mature L. hoffmeisteri upstream and downstream from the power station were influenced more by the increased temperature, than the increased oxygen levels of the power station effluent, though under extreme conditions of deoxygenation, aeration of the river by the cooling towers at the power stations could increase the abundance of this species.

Land reclamation and river pollution problems in the croal valley caused by waste from chromate manufacture

Abstract: Chromate salts were manufactured at the Hall Chemical Works, Little Lever, near Bolton, from 1880 until 1968. All that now remains on the site is the derelict works and two heaps of waste from the process. They are up to 15 m high, and consist of several hundred thousand tonnes of material. Most of the 15-ha site is devoid of vegetation and it is a conspicuous feature of the landscape of the Croal Valley. Reclamation of the site would greatly improve the amenity of the district. It would also mitigate river pollution, for at present, rain water drains into the nearby river Croal and carries with it 3-5 t of soluble chromium every year. This effluent water has a severe effect upon the river flora. Table 1 shows the algal and macrophyte flora upstream from the effluent, as well as 200 m and 1P5 km downstream. Even 1 5 km downstream, the flora shows little sign of recovery, and there was no detectable decrease in the concentration of chromium in the river water, which varied between 0-2 and 0 5 mg Cr/l. A grass cover on the waste heaps would return half of the rain water back to the atmosphere by evapotranspiration (Ministry of Agriculture 1962) and so reduce the volume of effluent water. Two other factors would influence the amount of chromium entering the river: the degree of saturation of chromium in the effluent and the area of the heaps after they have been flattened. Reclamation schemes have been proposed by the Lancashire County Council not only to alter the unsightly waste heaps but to improve the condition of the river Croal. Part of this work was carried out as a preliminary study of these schemes.

Disposal of organic pesticides

Abstract: 1. A WASTE-CONTROL PROCESS FOR THE ULTIMATE DISPOSAL OF AN ORGANIC PESTICIDE RESULTING IN NEGLIGIBLE ENVIRONMENTAL POLLUTION COMPRISING: FEEDING THE PESTICIDE AND A SOURCE OF OXYGEN INTO A POOL OF A MOLTEN SALT CONSISTING ESSENTIALLY OF AN ALKALI METAL CARBONATE OR MIXTURE OF ALKALI METAL CARBONATES OR A MAJOR PORTION OF AN AKALI METAL CARBONATE AND A MINOR PORTION OF AT LEAST 1 WT. PERCENT OF AN ALKALI METAL SULFATE TO THERMALLY DECOMPOSE AND AT LEAST PARTIALLY OXIDIZE SAID PESTICIDE TO FORM DECOMPOSITION PRODUCT INCLUDING A GASEOUS EFFLUENT, AND THEN VENTING A GASEOUS EFFLUENT PRODUCT CONSISTING ESSENTIALLY ONLY OF GAS SELECTED FROM CARBON DIOXIDE, WATER VAPOR, OXYGEN AND NITROGEN TO THE ATMOSPHERE WHILE RETAINING THE REMAINING DECOMPOSITION PRODUCT OF THE PESTICIDE IN THE MELT.

Sewage treatment system

Abstract: A sewage treatment system utilizing aerobic and anaerobic treatment. Anaerobic treatment of organic solids is utilized in a primary settling tank located at or near each sewage source which would also trap non-degradable solids. Liquid effluent from the settling tank is collected in a wet well storage which is either a intergral part of the settling tank or a separate container. The liquid is then intermittently pumped from the wet well by an inexpensive non grinder pump through pressure regulated lines to a central aerobic treatment plant for purification of the liquid effluent.

Process for the selective removal of sulfur dioxide from effluent gases

Abstract: Method for scrubbing SO2 and mixtures of SO2 and SO3 from effluent gases using aqueous trialkanolamines or tetrahydroxyalkyl alkylene diamines or the corresponding amine and diamine sulfites as the absorbent solvent composition has been developed. The method can be used even where the effluent gases contain a preponderance of CO2.

Copper etchant effluent treatment

Abstract: The copper content of aqueous effluent containing the rinsings from the etching of copper containing substrates is reduced to less than about 5 ppm., by the steps of: (a) adjusting the pH of the effluent to no more than about 4.; (b) providing in the effluent, while vigorously agitating, hydrogen peroxide and a water soluble compound such as calcium chloride; and (c) adding to the reaction mixture as required an alkaline material such as lime or a water soluble salt of carbonic acid, in an amount effective to adjust the pH to at least about 8.

Luxury uptake of phosphate by activated sludge.

Abstract: Phosphate's role in the eutrophication roc ss has been well documented, whether it is the limiting nutrient or not. Substantial efforts have been made re cently by the federal government and municipalities to limit the amount of phosphate ion that is released in effluents from waste water treatment plants. Under ordinary operating conditions the two most commonly used heterotrophic biological treatment processes, trickling filter instal lations and activated sludge aeration facili ties, have been reported to be capable of removing an average of only 20 and 40 percent, respectively, of the soluble phos phate concentrations normally found in municipal wastewaters.1 Clearly, addi tional treatment of phosphate ion is needed to reduce its effluent concentration in modern phosphate-rich waters. Under normal operating conditions, the biomass of the heterotrophic biological treatment plants removes organic carbon and phos phorus from the wastewater in a 106:1 ratio,2 and the sludges from such processes contain approximately 2 to 3 percent of their dry weight as phosphate.3 Current efforts to modify biological treatment systems, which have been in vestigated in the laboratory and to a limited extent in the field, involve the addition of chemicals containing cations that form insoluble phosphate precipitates, which are then removed from the waste water by conventional separation tech niques. Chemicals such as lime and ferric and aluminum salts are being used for this purpose. The chemicals conven tionally are added in a separate third stage process, but in some cases they have been successfully added directly to the secondary aeration tanks. A number of activated sludge waste water treatment plants, however, have reported phosphate removals of appreciably greater than 40 percent.4-7 These removals far exceed any typical 106:1 stoichiometric carbon : phosphorus ratio. At times, these treatment plants reportedly achieve a 90 to 95 percent phosphate removal, even in phosphate-rich wastewaters. Such excessive phosphate removal by an activated sludge process has been termed "luxurious uptake of phosphate," and much controversy has arisen over the mechanism by which this removal takes place. In 1965, Levin and Shapiro8 reported that this uptake was a biological one that was dependent on oxygen transfer into the cell and relatively independent of carbon con centration. In 1970, Menar and Jenkins9 reported that, in their opinion, such luxuri ous removals were a result of a chemical precipitation phenomenon, and, although the extent of removal was a direct function of the aeration rate, the removal was oxygen-transfer independent. In their scheme, the aeration process allegedly served to strip the metabolically-produced carbon dioxide (C02) from the sludge suspension. The resultant increase in pH induced the precipitation of some form of calcium phosphate, which then was re moved with the biomass during sludge separation. Two such divergent hypoth eses are contradictory and mutually ex clusive because both mechanisms cannot

Treatment of pulp mill effluents

Abstract: A multi-step method is provided for the purification of waste water, especially pulp mill effluents. It comprises a number of steps carried out in a specific sequence. The first step involves passing an oxygen-containing gas through the waste water while the waste water is in intimate contact with a finely divided activated carbonaceous material, preferably including, as a preliminary step, the addition of the finely divided activated carbonaceous material to the waste water. The second step involves adding a clarification agent selected from one or more of a coagulant, a flocculant, and a polyelectrolyte to the treated waste water provided by the first step. The third step involves recovering a solids-free effluent by known means, e.g. by a clarification step carried out by gravitational, flotational or centrifugal means to provide the waste water free of the suspended material originally contained therein and a sludge including the suspended material originally contained in the waste water, the added carbon and the added clarifying agent. Optionally, it includes the fourth step of regenerating the carbonaceous material from the sludge, and/or the fifth step of regenerating the clarification agent from the sludge.

Air and water pollution control

Abstract: Waste gas purification system using water scrubbers, wet filters and the like are combined with a multiple reuse of water system wherein suspended solids, absorbed volatiles and dissolved solids are economically and substantially completely removed from the waste water effluent and pure water is recovered for reuse in the gas purification process and for other purposes.

Undesirable Plant Responses with Sewage Irrigation

Abstract: A farmer using sewage effluent for irrigation is faced with the management problem of an uninterrupted supply of nutrient laden water that may contain toxic heavy metals. The yield and quality of marketable produce can be reduced if moderate levels of nitrogen are applied continuously, especially if the crop is a perennial. Plants can take up many of the minerals in sewage in excess of their needs. The plant becomes either toxic to its consumer or it dies from the mineral toxicity. Heavy metals are the biggest unknowns in the use of sewage effluent for irrigation. Once heavy metals become toxic in the soil solution, they are difficult to remove from the solution. Heavy metals will accumulate in the soil and become toxic unless the source of the heavy metals in the effluent is eliminated.

Dry collection of waste materials

Abstract: The noxious components of hot, gaseous effluents, e.g., the effluent from an incinerator, can be eliminated by a process which does not require an aqueous discharge. In the process the gaseous effluent is cooled in an evaporative cooler, particulates are then removed in a baghouse or other dry collecting device, the acid or basic gases in the effluent are then absorbed and converted to a salt solution or slurry in a scrubber, and the salt solution or slurry is recycled to the evaporative cooler.

Numbers and Types of Microorganisms in Silage and Effluent from Grass Ensiled with Different Additives

Abstract: (1973). Numbers and Types of Microorganisms in Silage and Effluent from Grass Ensiled with Different Additives. Acta Agriculturae Scandinavica: Vol. 23, No. 2, pp. 109-120.

Removal of tritium and tritium-containing compounds from a gaseous stream

Abstract: Tritiated species, e.g., tritium, tritiated water, and/or tritiated hydrocarbons, are removed from gas streams comprised thereof by reacting the same over a precious metal catalyst with sufficient air or oxygen to insure conversion of all tritiated species to tritiated water and, if hydrocarbons are present in the gaseous feedstock, carbon dioxide. The tritiated water and any other moisture that might be present in the reaction effluent are next adsorbed by a desiccant dryer, preferably to a level of less than one part per million. Most desirably, the desiccant dryer effluent is then diluted with non-radioactive water such that the tritiated water is diluted by a factor of at least about 1,000 to 1; the resulting water mixture can be adsorbed from the diluted effluent by a second dessicant dryer to provide a value in the ultimate effluent gas of less than about one-half parts per billion tritiated water.

Effluent gas recycling and recovery in electrolytic cells for production of aluminum from aluminum chloride

Abstract: Recycle system for the recovery and reuse of the effluent gas and additional values emitted in production of aluminum by electrolysis of aluminum chloride.

Method of and an apparatus for saving water used in toilets

Abstract: The water used for flushing toilets is the effluent from kitchen sinks, bath tubs, showers and wash basins A basin which receives excreta is so mounted that it pivots automatically when sufficient waste water has collected sending the collected excreta on toward the sewer A toilet which envelopes solid excreta in foam is described The foam prevents escape of odor prior to dumping

Method of decolorizing paper mill effluent liquid

Abstract: Effluent liquid normally discharged by paper mills is ecologically undesirable for return to streams, lakes or the like by reason of the presence of color-imparting substances, e.g., color bodies, desirably removed by a process which includes mixing therewith an excess of calcium carbonate, followed by a combination at a pressure above atmospheric with a fluid rich in carbon dioxide, serving to convert the calcium carbonate to soluble calcium bicarbonate which is in turn discharged to atmospheric pressure whereby the calcium bicarbonate reconverts to calcium carbonate precipitate, said precipitate attracting and sweeping said color-imparting color bodies; the precipitate and color bodies being readily separable from the color-free effluent which may be returned to the source, stream, river or lake or reintroduced as fresh water into the pulping process as needed.

Treatment of animal wastes

Abstract: A method is described for the treatment of animal wastes which facilitates the bacterial decomposition of the waste without many of the economic and operational hindrances of conventional waste treatment. According to the invention, an aqueous medium containing the animal waste is prepared and a foam stabilizer such as a surface active agent or a protective colloid is added to the resulting aqueous medium. The aqueous medium is then foamed into a stable foam with air in the discontinuous phase surrounded by the continuous aqueous medium. Preferably, the medium is innoculated with a bacterial culture before foaming. The foam is then discharged into the fermentation vessels where it is retained for a sufficient period of time, e.g., from about 3 to about 48 hours at a temperature from about 15* to about 60*C. to permit substantially complete bacterial decomposition of the animal waste products. Upon completion of the fermentation, the foam composition is removed from the fermentation vessel and a clear, aqueous effluent is separated for recycle in the process or for discharge. The bacterial cells can be concentrated from the aqueous medium by various solid-liquid separators and finally dried to recover cellular matter containing approximately 60 percent protein.