Closed Water Systems Research Articles

Books: Options for Closed Water Systems: Sustainable Water Management

Books: Options for Closed Water Systems: Sustainable Water Management

3-D NUMERICAL CALCULATION OF DESITY FLOW FOR ADVANCE AND INNER SEICHE

In the stratified closed water systems such as bays, lakes, and river mouths flowing into sea, the unique phenomena caused by the density differences are observed. Numerical simulation is useful for investigating such phenomena and three-dimentional numerical models are required when it have occured under the effects of changeable wind direction and complicated ground shape. In this paper, a three-dimensional numerical model which employs LES and CIP methods is proposed for the purpose of calculating incompressible density current. The model is closs-checked by the results of an experimental density flow in a flume, in which the movement of density front and internal seiche can be observed. The applicability of such a process is confirmed by the calculated results of miglation of density front, vortexes behind it, diffusion of inner density boundary, and period of internal seiche.

Potential of closed water systems on dairy farms

A more sustainable water management on dairy farms is necessary because of rising tap water production costs and exhaustion of groundwater resources in an increasing number of areas. Alternative water sources like rain water collected from roofs and yards and effluents from on-site wastewater treatment should be considered. The objective of this paper is to discuss options for closed water systems on dairy farms. Animal drinking and cleaning of milking equipment are major water demands on dairy farms. In some regions large volumes are needed for grassland irrigation or manure flushing. Treatment of dairy farm wastewater in constructed wetland systems seems to produce good quality effluents. The most plausible options for closed water systems on dairy farms are the collection and use of rain water and treatment and reuse of wastewater for irrigation, manure flushing and animal drinking water. Whether effluents are safe to be used as animal drinking water should be subject to further research.

Potential of closed water systems on dairy farms

A more sustainable water management on dairy farms is necessary because of rising tap water production costs and exhaustion of groundwater resources in an increasing number of areas. Alternative water sources like rain water collected from roofs and yards and effluents from on-site wastewater treatment should be considered. The objective of this paper is to discuss options for closed water systems on dairy farms. Animal drinking and cleaning of milking equipment are major water demands on dairy farms. In some regions large volumes are needed for grassland irrigation or manure flushing. Treatment of dairy farm wastewater in constructed wetland systems seems to produce good quality effluents. The most plausible options for closed water systems on dairy farms are the collection and use of rain water and treatment and reuse of wastewater for irrigation, manure flushing and animal drinking water. Whether effluents are safe to be used as animal drinking water should be subject to f&her research.

NUMERICAL CALCULATION OF FLOW AND MIXING IN VERTICAL BOUNDARY SURFACE OF DENSITY

A numerical model is one of the useful measures to predict the characteristics of the environmental systems on the interface of different density water. In the last few years, some models were already proposed to calculate each problems like flow in the stratified closed water systems and the saltwedge, and realized beneficial results. However, these models also have some defects. For example, turbulent models are sometimes difficult to use actually because of its theoreticalcomplexity, and simple two-dimensional models can not calculate so accurately. So in this paper, the new two-dimensional numerical model is proposed, which use CIP-scheme in the calculation of advection phase, in order to calculate density flow more accurately without using complicated models, and its availability is confirmed by the comparison between the results of the calculation and that of the experiment under the same condition.

Hormonal sex reversal of tilapias: implications of hormone treatment application in closed water systems

The phenomenon of incidental sex reversal was observed in experiments originally designed to determine the importance of feeding duration and feed quality in the optimization of masculinization and feminization treatments of Oreochromis niloticus (L.) fry by oral application of hormones. Four separate experiments were conducted: (1) masculinization and (2) feminization using three feeding durations and (3) masculinization and (4) feminization using three alternative feed mixtures. Masculinization experiments incorporating 17 α-methyltestosterone (MT) into the feed at 40 mg kg−1 were applied to putative monosex male progeny whilst feminization treatments were applied to putative all female fry using diethylstilboestrol (DES) at 1000 mg kg−1. Treatments were applied outdoors in small cages suspended in 900-l circular concrete tanks with a flow through rate of 1-l min−1. Replicate cages for all treatments and the controls in each experiment were reared together in the same tank. Only the first experiment produced significant differences in sex ratio, with the control treatment producing a slightly lower proportion of males than the three MT treatments at different durations. The most significant finding was that in all experiments the sex ratio of the control differed significantly from expectations and in all but experiment 1, did not differ from those of the treated fish in which sex reversal had clearly been effected. It appears likely that incidental sex reversal occurred in the control fish as a result of the accumulation of active metabolites from the treated fish and/or leachates from uneaten food given to fish in the same water body. The results are discussed in the context of improving the efficiency and safety of hormonal sex reversal treatments.

Hormonal sex reversal of tilapias: implications of hormone treatment application in closed water systems

Hormonal sex reversal of tilapias: implications of hormone treatment application in closed water systems

Cone Penetration of Partially Saturated Sands

Abstract A laboratory study of cone penetration through partially saturated sand was conducted. A new method for preparing specimens at various degrees of saturation, which utilizes pressure release from previously carbonated water, is described. In closed water systems, where capillary tensions increase effective confining pressures, penetration resistance was significantly higher than in either dry or saturated conditions. Conversely, in closed-gas systems the penetration resistance was slightly lower than at full saturation.

Sulfate-reducing Bacteria and Their Activities in Oil Production

Summary. This paper presents an overview of the microbiology of sulfate-reducing bacteria (SRB) and their detrimental effects in oil technology and summarizes a study on SRB in an oil field. SRB are a group of specialized microorganisms that occur in aqueous environments in the absence of oxygen. The main nutrients for SRB are simple organic acids and molecular hydrogen (H2) from decomposing natural organic matter. The nutrients are oxidized, with sulfate being reduced to sulfide (hydrogen sulfide, H2S). The formed H2S is the principal agent in the disastrous effects caused by SRB. It contaminates gas and stored oil, precipitates ferrous sulfide that plugs injection wells, and promotes precipitates ferrous sulfide that plugs injection wells, and promotes corrosion of iron and steel in the absence of oxygen (anaerobic corrosion). Another principal mechanism by which SRB are involved in corrosion is their ability to depolarize iron surfaces by consumption of cathodically formed hydrogen. The postulated mechanism in anaerobic corrosion are briefly explained. As an example for a microbiological study of SRB in oil technology, examination of an oil treater in a field in northern Germany is presented. On the basis of measured growth characteristics of the SRB, presented. On the basis of measured growth characteristics of the SRB, possibilities for controlling their activity are discussed. possibilities for controlling their activity are discussed. Introduction Biological sulfate reduction by SRB is the only known process by which, in aquatic environments of moderate process by which, in aquatic environments of moderate temperatures (O to 75 degrees C [32 to 167 degrees F]), H2S is formed from sulfate. In sediments of ponds, lakes, and marine environments, SRB are usually part of the indigenous community of microorganisms and are rather inconspicuous in nonpolluted waters. In oilfield water systems, however, SRB cause serious problems:corrosion of iron in the absence of air (anaerobic corrosion),precipitation of amorphous ferrous sulfide that, by precipitation of amorphous ferrous sulfide that, by plugging, diminishes the in injectivity of water injection wells, plugging, diminishes the in injectivity of water injection wells,contamination of fuel gas with H2S, andcontamination of stored fuel oil with H2S. Furthermore, H2S is extremely toxic if inhaled: it easily escapes from contaminated waters and may accumulate under poorly ventilated conditions. It is usually recognized by its distinctive, unpleasant odor, but high concentrations anesthetize the sense of smell. The objective of this paper is to present an overview of" the biological features of SRB and of their activities in oil technology with emphasis on anaerobic corrosion. We also include results from our studies on SRB in an oil field in northern Germany. Microbiology of SRB SRB are an assemblage of specialized bacteria that thrive in the absence of oxygen and obtain energy for growth by, oxidation of organic nutrients, with sulfate being reduced to H2S. The biological significance of this form of life is best understood within the overall natural decomposition process carried out by living organisms. Processes in Biological Decomposition. The natural Processes in Biological Decomposition. The natural decomposition of organic material in our biosphere through a food chain of oxygen-breathing (respiring) organisms-namely, animals, fungi, and bacteria-is a well-known process. Biochemically, respiration is a transport of reducing power (hydrogen, "electrons") from the organic nutrients (organic substrates, electron donors) being oxidized to oxygen (electron acceptor) being reduced (Fig. la). Respiration liberates the energy that has been originally conserved in the organic matter during photosynthesis by green plants and cyanobacteria photosynthesis by green plants and cyanobacteria (bluegreen algae). In the oxygen-breathing organisms, the liberated energy is used for maintenance of their living structures and for growth-i.e., a net synthesis of their own cell material from the nutrients. Thus every organic substrate of a respiring organism is partly decomposed for obtaining energy and partly converted into new cell material. These functionally distinctive reactions in living organisms are designated catabolism or dissimilation (energy metabolism) and anabolism or assimilation (cell synthesis), respectively. An amount of biomass initially synthesized by photosynthesis is diminished more and more by passing through the food chain because of respiratory losses. The final result is a reoxidation (mineralization) of the chemically complex biomass to CO7, H2O, and other minerals (Fig. 1a). These inorganic end products are used by green plants and cyanobacteria for products are used by green plants and cyanobacteria for photosynthesis of new organic substances (the natural cycle photosynthesis of new organic substances (the natural cycle of matter). The total reoxidation of biomass is possible only if the conditions are aerobic- i.e., if sufficient oxygen is present. If biomass gets into stagnant or rather closed water present. If biomass gets into stagnant or rather closed water systems where the gas exchange with the atmosphere is limited, dissolved oxygen may be completely consumed. JPT p. 97

Method for reducing water corrosivity in circulating water systems of petroleum refineries

Under the conditions of recirculating water systems with mixed oxygen/hydrogen depolarization, the authors advise using nontoxic passivating inhibitors, among which the most promising are phosphorus containing reagents, particularly polyphosphates and their combinations with inorganic and organic additives, which give a high level of protection even at concentrations of 15-20 mg/liter. At the Odessa Petroleum Refinery, a combination of sodium nitrite and sodium tripolyphosphate (TPP) has made it possible to achieve more than 85% protection (St3 steel) with a total component concentration of 100-200 mg/liter, with practically no local corrosion in the system. TPP is especially promising when the change is made to industrial installations with closed water systems with combined treatment of water.

Corrosion of Aluminium in Multimetal Water Systems

AbstractThe thermodynamic conditions of chemical stability for the three-metal, Aluminium—Copper—Steel/ closed water systems are outlined, together with an account of the corrosion behaviour of aluminium as affected by the pH of the water and the presence of inhibitors. A practical case is described of incorrect chemical treatment of the recirculating water in an air-conditioning multimetal system, leading to overall instability of the protective aluminium oxide layer with typical forms of aluminium attack arising from a combination of high alkalinity (here due to borate) with too low a concentration of inhibitor, and water turbulence.

Measures against water pollution in mechanical pulp and paper mills.

Large sums have been and are being invested in the forest industry for water preservation but the result of the investments has not been as efficient as hoped. The basic mechanism in flotation, flocculation and sedimentation is still partly unknown, despite the research carried out in the field. Research should be more systematically organized globally and carried out at an intense and escalated pace. Large amounts of money should not be invested on half-measures, without the necessary knowledge of the return in efficiency. The flow of information regarding the progress of research should be intensified. Organized cooperation of all parties concerned should be established with the aim of achieving the most effective and economical use of the collective resources of the industry and the government. The first questions to be asked are: What is discharged with the effluent water from mechanical pulp and paper mills and what influence does this have on th.e recipient? What problems occur in the treatment of waste water? It should be pointed out that as far as waste water problems are concerned the mechanical pulp and paper mill is not one of the most troublesome within the forest industry. Our main problem is to reduce effectively the discharge of fibre suspensions to an absolute minimum. These suspensions contain bark residue, fines of groundwood pulp, fibres of chemical puips being used and in some cases a certain amount of clay. From a biological point of view the influence of these suspensions is relatively low but noticeable. The waste water from a mechanical pulp and paper mill can have the following characteristics: pH around 5.0—5.5 Dry substance before treatment of about 500—700 ppm Dry substance after treatment of about 100—200 ppm, i.e. a cleaning effect of about 70 per cent. BOD7 (20°C) about 12 kg/ton daily. All mechanical pulp and paper mills have been fighting with slime problems. Owing to the extended use of closed water systems, these problems have

Scientific Principles of the Complex Utilization and Conservation of Water Resources

AbstractA leading water-resource geographer outlines a series of measures that, in his view, would assure mankind with an unpolluted water supply for many more generations. He opposes the view that inland waters are virtually lost to man as a source of water and that other sources such as desalting of seawater or melting of icebergs must be sought. The proposed measures envisage the gradual reduction and ultimately halting of the discharge of wastes and sewage into streams and lakes by the use of municipal sewage for irrigation of forage crops near urban centers and the provision of closed water systems within industrial plants, including treatment and reuse of wastes.

Reinjection of Large Volumes of Produced Water in Secondary Operations

Abstract A study was made of the operating performance histories of a pressure-maintenance and four waterflood projects in the Permian Basin area, where large volumes of produced water have been reinjected into the producing formations. The projects reviewed include a wide range of characteristics: open and closed water systems, volumes of reinjected water froth 2,200 to 12,500 B/D, sand and limestone formations, depths of 1.300 to 6,750 ft. average permeabilities from 17 to 275 md, bare and protected facilities, and 10- to 50-year project life. Each project exhibited performance data which indicated that reinjection of large volumes of produced water provides a good source of injection fluid, results in practical and prudent salt water disposal and, in many cases, results in conservation of fresh water for future domestic needs. Introduction The increasing difficulty of finding adequate new oil reserves has caused almost every field in West Texas to be reviewed for possible secondary recovery applications. Because most secondary recovery processes use water, the availability and prudent utilization of water are very important to all oil operators. Standard Oil Co. of Texas' production operations in West Texas include numerous water floods, and several of these projects are reviewed and discussed in this paper. The case histories presented cover handling and reinjecting large volumes of produced water. The fields presented, as shown in Fig. 1. include SACROC unit, Howard-Glasscock, North Ward-Estes. Keystone-Colby sand, and South Ward. The combined cumulative primary and waterflood recovery of these fields to Jan., 1965. is 878.8 million bbl. Pertinent reservoir and waterflood data for the Standard of Texas' projects in each field are shown in Tables 1 and 2. Equipment used and materials for construction in each injection system are shown in Table 3. Waterflood performance histories are shown in Figs. 2 through 7. Schematic flow diagrams of the injection systems are shown in Figs. 9 through 13. SACROC Unit History and Development The Canyon Reef reservoir of the Kelly-Snyder field in Scurry County was discovered in Nov., 1948. The field now encompasses some 50,000 productive acres and 1,321 wells. Cumulative field recovery to Jan., 1965, is 322.4 million bbl. The reef, a limestone formation, is a low mound-type structure varying In thickness from 0 to 800 ft. The field was essentially developed by 1951; and, after extensive negotiations, the field was unitized with a unit manager and three segments, each operated by a working-interest owner effective March, 1953. Standard of Texas was designated unit operator on May 1, 1962. JPT P. 781ˆ