Showing papers on "Wastewater published in 1970"

Ammonium removal from secondary effluents by selective ion-exchange

Abstract: Early in the developing science of water pollution control, the presence of ammonia in groundand surface water supplies was regarded as a strong indication of recent pollution (1). Klein (2) has stated that am monia concentrations of greater than 0.2 mg/1 are a strong indication of pollution by wastewater. More ex plicitly, McKee and Wolf (3) state that: "The generally accepted limit for free ammonia for sanitary purity of water supplies is between 0.05 and 0.10 mg/1. Excess of this value ren ders the water suspect of recent pollu tion." While ammonia-nitrogen is commonly observed in surface waters, it is not found in groundwaters ex cept in small amounts under anaerobic conditions (4). As water quality science progressed, it became apparent that the presence of ammonia in water has far more seri ous implications than merely serving as an index of recent pollution. It was demonstrated that:

Apparatus and process to treat waste water for pollution control and industrial reuse

Abstract: Apparatus and process for removing colloidal, oxygen demanding and odor causing organic materials, inorganic materials and other pollutants from waste water is provided. The initial pH and resistivity of the water is measured and adjusted to predetermined values. The color of the water is then measured and organic and inorganic materials are caused to precipitate from the water which is then subjected to a predetermined density of electrical current. The electrolysis coalesces colloidal materials which are removed mechanically and causes additional material precipitation, as well as acting to kill bacteria, viruses and other organic matter. Additional inorganic matter precipitation is induced and the water has a final pH, color and resistivity adjustment. An oxidizing agent is added to further reduce oxygen demanding and odor causing organic material and act on bacteria and other organic matter remaining. The water is then reusable or may be discharged into streams or sewer facilities.

Removal of nitrogen and phosphorus from waste waters

Abstract: Nitrogen and phosphorus are removed from waste waters by a process including the steps of biological nitrification, chemical precipitation of phosphorus and biological dentrification. Buffering capacity of the water is substantially reduced and in some cases nearly eliminated by reaction of acid, produced in the nitrification step, with bicarbonate ion contained in the waste water. A precipitate containing phosphate in high concentration is recovered at low chemical cost.

Wastewater treatment system

Abstract: In a shipboard system, wastewater is withdrawn from a storage tank and is comminuted to reduce the size of waste solids. Coagulant is added, and the wastewater is centrifuged. Solid wastes are incinerated. The liquid wastes are disinfected and dissolved organic material is adsorbed in activated carbon. An effluent of tertiary quality is discharged.

Evaluations of the availability of sources of nitrogen and phosphorus for algae1

Abstract: SUMMARY Techniques are compared for the evaluation of nutrient sources in which the potential nutrients are in contact with algae over their entire culture period versus relatively short-term exposure tests. Different nitrogen and phosphorus compounds were shown to be utilized in darkness as well as in light and were equally available at pH 7 and 9. The availability of relatively insoluble nutrients–iron-phosphorus compounds and teeth for phosphorus, hair for nitrogen iron pyrites for iron, and marble for carbon–indicates that in many cases the equilibrium between soluble and insoluble forms allows algae to compete successfully with insoluble forms for nutrients. Apparently, factors other than mere insolubility prevent algae from obtaining available nitrogen or phosphorus from phosphate rock or lake muds. Live algae or aquatic weeds with adequate or surplus nitrogen or phosphorus were shown to not share their nutrients with nitrogen- or phosphorus-limited algae, whereas the nutrients of killed algae or aquatic weeds were readily used by nutrient-limited algae. The facts–(1) that live algae and aquatic weeds do not share their adequate or surplus nutrients with nutrient-limited algae and (2) that lake muds do not provide readily available nitrogen or phosphorus–indicate that once lake waters are stripped of available nutrients by plant production, further plant production will depend upon nutrients from continuous sources of nutrients, such as wastewater effluents.

High quality reuse water by chemical-physical wastewater treatment

Abstract: In recent years more communities are finding that their demand for water is overextending or approaching the limit of their existing water sup ply. As a result, the need for new water sources has increased. One method that can be used to augment conventional water sources to meet these community needs is wastewater reclamation. The sequence of treat ments usually followed to reclaim wastewater for reuse is made up of biological, chemical, and physical proc esses. The terminal unit process usu ally is activated carbon adsorption be cause it has been found to be an excel lent choice in terms of adequacy and economic feasibility. Since the waste water reclamation treatment is a se quence of pretreatments before acti vated carbon adsorption, the emphasis of this research was to optimize the activated carbon adsorption step by determining the proper pretreatment process. In this way the wastewater reclamation process could yield high quality water at maximum efficiency. This study, started in 1966, was di vided into two distinctly different ap

Apparatus for treating sewage

Abstract: A waste water treatment apparatus and method in which completely submerged movable biological contactors, such as rotating disks, are used to provide biological treatment of waste water in a treatment tank. The completely submerged biological contactors provide a surface for attachment and growth of microorganisms and provide contact between the attached biomass and the impurities in the waste water. Suitable aerating means, such as partially submerged rotating disks, provide aeration of the waste water to maintain aerobic biological activity in the attached biomass on the completely submerged biological contactors.

The distribution of mean monthly precipitable water vapor and annual precipitation efficiency in Nigeria

Abstract: Precipitable water vapor was calculated for Nigeria using a combination of surface and upper air data and mean monthly maps have been drawn. Annual maps of precipitable water vapor and precipitation efficiency have also been included.

Process for recovering mercury from waste waters of industrial processes

Abstract: MERCURY PRESENT IN WASTE WATERS FROM INDUSTRIAL PROCESSES, SUCH AS THE ELECTROLYSIS OF ALKALINE-CHLORIDES USING THE AMALGAM METHOD, IS RECOVERED TO PREVENT LOSSES THEREOF AND TO PREVENT ECOLOGICAL CONTAMINATION OF WATERWAYS. RECOVERY IS ACCOMPLISHED BY CONVERTING THE MERCURY TO LOW-WATER-SOLUBILITY COMPOUNDS AND/OR TO METALLIC MERCURY BY THE USE OF PRECIPITANTS AND SUBSEQUENT SEPARATION THEREOF FROM THE WASTE WATER.

Method for water and wastewater treatment

Abstract: INCREASING THE EFFICIENCY OF CONTINUOUS FLOW WATER AND WASTEWATER TREATMENT PLANTS BY MIXING THE WATER OR WASTEWATER WITH A FLOC FORMING CHEMICAL IN A FIRST MIXING STAGE AT A SPEED EFFECTING A MEAN VELOCITY GRADIENT CORRESPONDING TO A FLOW VOLUME CONCENTRATION LESS THAN 300 PARTS PER MILLION UNTIL FLOCCULATION IS SUBSTANTIALLY COMPLETE AND THEN EITHER PASSING IT THROUGH A RAPID FILTER OR ALTERATIVELY MIXING IT IN A SECOND MIXING STAGE AT A LESSER SPEED EFFECTING A VELOCITY GRADIENT CORRESPONDING TO A SELECTED EFFUENT FLOC VOLUME CONCENTRATION GREATER THAN 300 PARTS PER MILLION BEFORE PASSING ON TO SUBSEQUENT TREATMENT SUCH AS SETTLING ND FILTERING.

Ecological Management Problems Caused by Heated Waste Water Discharge Into the Aquatic Environment

Abstract: Discharge of heated waste water may affect the entire aquatic ecosystem–the interrelated biological, chemical, physical system–and, if the temperature change is large, may destroy the capacity of the ecosystem to serve a variety of beneficial purposes. However, it is possible to discharge heated waste water in carefully controlled amounts without seriously degrading the aquatic ecosystem. There are four basic alternatives which are open to us with regard to the heated waste water problem which we may choose singly or in various combinations: (1) Placing all heated, waste water in streams, lakes, and oceans without regard to the effects. Thus considering the environmental damage as a necessary consequence of our increased power demand. (2) Using, but not abusing, existing ecosystems. This means regulating the heated waste water discharge to fit the receiving capacity of the ecosystem. (3) Finding alternative ways to dissipate or beneficially use waste heat. (4) Modifying ecosystems to fit the new temperature conditions. We are all dependent upon a life-support system which is partly industrial and partly ecological. Unfortunately, we have reached a stage of development where the non-expandable, ecological portion of our life-support system is endangered by the expanding industrial portion. Optimal function and full beneficial use of both portions of our life-support system will only be possible if a variety of disciplines and diverse points of view can cooperate and work together effectively. Since wastes in amounts that are acceptable taken one at a time may be lethal collectively, environmental management should be on a regional basis.

Respiratory relationships of a symbiotic algal‐bacterial culture for wastewater nutrient removal

Abstract: A continuous symbiotic algal-bacterial system was developed consisting essentially of a mixed Chlorella-activated sludge culture which would efficiently remove nutrients from wastewater under aerobic conditions without supplementary aeration. Oxygen decline data were fitted to a mathematical model used to predict respiratory rates, photosynthetic oxygenation, and steady-state oxygen concentrations. Stable relative biological populations and a dissolved oxygen concentration of about 2 mg/1 were maintained during steady-state operation with daily harvesting of excess biomass. Respiratory and physiological relationships indicated that the carbon dioxide-oxygen balance is a primary control that governs the steady-state operation of a symbiotic algal-bacterial culture. The close association of the algae and bacteria resulted in an algal-bacterial floc with settled rapidly yielding a clear supernatant.

Virus Inactivation during Phosphate Precipitation

Abstract: Phosphate removal from aqueous solutions by precipitation with calcium and aluminum results in large poliovirus Type I and bacteriophage T2 removals. Tests conducted in distilled water-phosphate solutions and filtered domestic wastewater effluent are described. The Freundlich isotherm is used to predict the removal of the two viruses from distilled water solutions. The pH during precipitation affects poliovirus removals. The mechanism of removal is believed to be mostly by chemical adsorption with some physical sorption occurring simultaneously. This is concluded from the inability to recover all viruses from the sludge. The sludge represents a potential health hazard and must be carefully handled. Virus removals are greater in distilled water-phosphate solutions than in wastewater treatment plant effluent. Results are extended to full scale treatment plants indicating that virus removals in excess of 98% and 92% may be expected from precipitation processes using aluminum or calcium, respectively.

Real-time computer control of urban runoff

Abstract: Computer control and modernization of combined sewer overflow regulators and an urban hydrology hydraulic mathematical model are described. The system has been installed to control the Minneapolis-St. Paul sewer system during stormwater runoff to improve the utilization of the existing interceptor sewers. Key stormwater regulators were modified to provide remote control of hydraulically operated gates and inflatable dams. Trunk sewer and interceptor sewer level monitoring stations and rain gauges are used as input to a mathematical model consisting of: (1) rainfall-runoff model; (2) stormwater diversion model; and (3) flood routing in the interceptor sewer. A high-density river quality monitoring system has been installed to determine quality effects of runoff events and to evaluate the effectiveness of the control system. Automatic sampling and automated wet chemical analysis of wastewater have been used to identify hourly quality variations in the wastewater.

Wastewater Reuse—A Supplemental Supply

Abstract: Historically, Los Angeles County has learned to quench its thirst from many sources. Completion of the California Water Project in 1971-72 and the second barrel of the Owen River Aqueduct in 1972 will ensure adequate supplies until about 1990. These high quality imported waters will also enhance the quality of treated wastewater for subsequent reuse. Undoubtedly, much of this better quality water will be used directly for irrigation or percolation to the underground. New processes resulting from a rapidly developing technology can be readily integrated into the water renovation plants not being operated or under construction by the Sanitation Districts as new reuse applications arise. Ultimately, demineralization of wastewater may be practical on a large scale, since processes now under development appear competitive with alternative sources of supply. While a significant quantity of wastewater is suitable for treatment and reuse, it should be considered in its proper role—as a supplemental supply.

Relationship of chlorophyll A to algal count and classification in oxidation ponds.

Abstract: In line with the thinking just men tioned and because of inadequate and conflicting information found in the literature concerning the species present at different seasons of the year, daily counts and classifications of organisms were made at the Trinity River Authority of Texas wastewater treat ment plant over a period of 16 months. The types of algae found in the oxida tion pond effluent (plant effluent) in any appreciable numbers during this period differed, to a large extent, from those reported in the literature. The predominating species of organisms found by the authors included : Anacys tis, Chlorella, Scenedesmus, Coelastrum, Oocystis, Desmids, Zygnema, and Closterium. This study was aimed at obtaining a quantitative comparison of chlorophyll A with the total number of organisms in the Trinity River Authority waste water treatment plant as well as a comparison with the various species of algae existing from time to time in these oxidation ponds.

Performance of chitosan as a primary coagulant for the wastewater treatment

Abstract: Chitosan (1,4,2-amino-2-deoxy-β-D-glucan), a component of the shell of marine crustaceans, is one of the most abundant organic polymers present in nature. Because of its positive charge and molecular structure, chitosan possesses valuable properties as a metal-recovering and water-purifying agent. Given the increasing use of chemical coagulants to improve the water treatment process, studying chitosan has become very important. The goal of this study was the performance of chitosan as a primary coagulant for the removal of copper (Cu 2+ ) and turbidity from wastewater. The removal of zinc by chitosan was also investigated. Coagulation-flocculation-sedimentation experiments were performed by jar tests (Phipps and Bird, USA) on drinking water mixed with sanitary sewage, with industrial wastewater and with a bentonite suspension. The results showed that chitosan is superior to alum when used as a primary coagulant in a mixture of drinking water with industrial wastewater. 40 mg/L of chitosan permitted 100% elimination of copper from drinking water mixed with industrial wastewater at proportions of 35 and 47%. The use of chitosan as a primary coagulant is more effective than the other classical coagulant in term of toxicity and waste disposal. Chitosan is superior to alum especially when the turbidity and alkalinity of water is high. In our study, the main factors affecting the coagulation-flocculation by chitosan were the physico-chemical characteristics of raw water and the type and concentration of different chemical compounds present in the water.

A Modified Method For The Determination OfChemical Oxygen Demand In Sea Water

Abstract: A modified method for the determination of the chemical oxygen demand in sea water is presented in this paper. The proposed method differs from the alternate method for low COD samples described in the 17th edition of the Standard Methods for the Examination of Water and Wastewater in that it employs a pretreatment step resulting in complete halides removal from the sea water sample. Complete removal of halides is realised by adding 3 g silver sulphate per 30 ml sea water sample in a 50 ml erlenmeyer flask and mixing for 60- 90 min (when a fade lilac colour appears) followed by settling of the precipitates formed for 5-10 min with the flask in a 40 ° inclined position and finally taking slowly and with care the volume of the cleared sea water required for the COD test with a volumetric pipette.

Low-Pressure Ultrafiltration Systems for Wastewater Contaminant Removal

Abstract: Low-pressure ultrafiltration is still in the preliminary stages of development as a unit process in municipal waste and wastewater treatment. Recently, the membrane process of reverse osmosis, developed initially for use in desalination, has attracted attention as a promising method for treatment of wastewaters. Data on the separation or removal of pure organic solutes is needed to evaluate the potential application of ultrafiltration systems in wastewater treatment. The organic solutes in wastewater streams cannot, in general, be economically recovered by chemical means. Ultrafiltration has the potential of making possible the economic treatment of at least some industrial wastewaters. A pertinent example is the pulp and paper industry, in particular, research efforts now being conducted by the Pulp Manufacturers Research League.(1,2,3) studies carried out on reverse-osmosis treatment of secondary-sewage plant effluent at Pomona, California(4), have demonstrated the feasibility of reverse osmosis for treatment of complex wastewaters containing relatively high concentrations of organic pollutants.

Hydrology of Spray-Runoff Wastwater Treatment

Abstract: Liquid measuring procedures used in a 12-month study of the hydrology of the soil treatment system at Campbell Soup Company's Paris, Texas plant accounted for 93% of the total liquid applied to the soil. The rainfall and wastewater applied to the soil system are accounted for as follows: 18% is lost to the atmosphere through evaporative processes; 61% is recovered as runoff; and 21% percolates through the soil. The fraction of the treated wastewater recovered as runoff ranges from a low of 30% to a high of 85%. This range in the percent runoff is influenced by climate, soil textural class, and wastewater spray schedules. Wastewater spray schedules are controlled to partially offset variations in the percent runoff which would normally occur as the result of climatic influences.

Model Derivations For Nutrient Diversion OnLakes

Abstract: Lakes are frequently subjected to wastewater discharges If nutrients like nitrogen, phosphorus and carbon are present in sufficiently large amounts, the water body will be polluted and eutrophication can take place Eutrophication of a lake induced by municipal wastes can be retarded by removing the source of plant nutrients, notably phosphorus This is accomplished by diversion of the effluent around the lake, or by treatment of the wastewater employing advanced treatment processes In this study, first a mathematical model with different assumptions about nutrient exchange processes is introduced, then the mass balance considering input, output, net loss to the sediments was used to predict the lake nutrient concentration as a function of nutrient residence time Lake Iznik located in the southern part of the Marmara region of Turkey is subjected to three different levels of nutrient loadings, with a certain amount of diversions each time to study the response of the lake

Optimisation Of The Operating Parameters InAn Experimental DAF Process For WastewaterTreatment

Abstract: Many water and effluent treatment processes involve the separation of solids from a liquid phase, whether the solids are present naturally or result from the treatment process itself. Dissolved Air Flotation, DAF, is a particularly effective means of attaining solid/liquid separation,and its field of application is extensive. In a DAF process, air and water are mixed together at a high pressure, causing the air to dissolve in the water. The resultant dispersion water, ideally bubblefree, is released into a flotation vessel, where it mixes with the wastewater to be treated. The sudden reduction of pressure effected by the release device, generates a mass of minute air bubbles as the air comes out of solution. Attachment of the bubbles to the solid material present in the wastewater accomplishes its removal by lifting it to the surface, from where it may then be removed.