二氧化氯杀菌处理石化循环冷却水

以硫酸盐还原菌,铁细菌以及异养菌数为指标,研究二氧化氯对石化厂循环冷却水的杀菌效果。考察了二氧化氯投加量,杀菌时间,温度及pH以及余氯量随时间的变化。结果表明,在CLO2投加量为3mg／L、灭菌时间为90min时,出水细菌数即可达到化工行业循环冷却水处理标准,并且余氯可在0．5-1．0mg／L范围内维持2h。温度和pH的改变对杀菌效果影响不大。     

THE STABILITY IN WATER OF A NEW CHLORAMINE DISINFECTANT1

ABSTRACT: The stability in water of a novel new chloramine agent, 3-chloro-4, 4-dimethyl-2-oxazolidinone (agent I), which is an excellent water disinfectant, has been compared to the stabilities of several other water disinfectants. The agents tested in addition to agent I included N-chlorosuccinimide, 2, 4-dichloro-5, 5-dimethylhydantoin, tichloroisocyanuric acid, calcium hypochlorite, commercial grade HTH, and household bleach. The total chlorine content of a water solution of agent I in a demand free environment remains constant over a period of at least eight weeks, while that for all of the other agents declines markedly over that time period. An explanation for these observations will be offered. Prior work in these laboratories concerning use of agent I as a disinfectant for lake water in a laboratory scale treatment plant had shown that agent I has considerable potential for use as an alternative to chlorine gas for water disinfection.     

炉渣用于深层过滤的试验研究

将炉渣用作深层过滤的床层过滤,在油田水处理中具有良好的应用前景。通过对炉渣滤料的物性测定,对流体力学性能、过滤性能及反洗性能的研究,获得了有关炉渣滤料的粒径分布、床层孔隙率、密度、吸水率等物性参数,以及清洁滤料床层阻力与速度的关系曲线和流化曲线,过滤条件下床层阻力随时间的变化关系和悬浮物脱除率随时间的变化曲线,炉渣床层的反洗曲线。结果表明：炉渣表面粗糙,有棱角,吸附表面积大,孔隙率大,过滤效果好;炉渣滤料密度小,反洗效果较好,反洗用水量只是过滤水量的５％左右;同时,炉渣作为滤料用于深层过滤,不仅来源广泛,而且属废物利用。     

氯消毒新工艺对大肠杆菌灭活作用的研究

研究了短时游离氯后转氯胺的联合消毒方法对大肠杆菌的灭活作用,并对其协同作用以及pH值和温度对协同作用的影响进行了探讨。结果表明：pH值在6．5～8范围内,温度不超过30℃时,短时游离氯后转氯胺的消毒方法对大肠杆菌的灭活具有协同作用,且随pH值的降低而加强,在低温下该方法的协同效果更加明显。     

A NOVEL CHLORAMINE COMPOUND FOR WATER DISINFECTION1

A new chloramine agent, 3-chloio-4, 4-dimethyl-2-oxazolidinone, has been tested in a laboratory scale water treatment plant as to its efficacy in water disinfection. The agent seems to be equally effective as compared to chlorine gas in this application. The results of preliminary toxicity studies on the agent are very encouraging. The agent has a long shelf life both in water solution and in the solid state. Being a solid, the agent is clearly less hazardous to handle than chlorine gas. The agent appears to inhibit oxidative corrosion of metals as well. The agent is less likely to produce toxic halocarbons (e.g., chloroform) in water than is chlorine gas. Possibly most important from the standpoint of water disinfection, the agent is a “slow release” one for its positive chlorine, which provides prolonged bactericidal activity.     

Real-time contaminant detection and classification in a drinking water pipe using conventional water quality sensors: Techniques and experimental results

Accurate detection and identification of natural or intentional contamination events in a drinking water pipe is critical to drinking water supply security and health risk management. To use conventional water quality sensors for the purpose, we have explored a real-time event adaptive detection, identification and warning (READiw) methodology and examined it using pilot-scale pipe flow experiments of 11 chemical and biological contaminants each at three concentration levels. The tested contaminants include pesticide and herbicides (aldicarb, glyphosate and dicamba), alkaloids (nicotine and colchicine), E. coli in terrific broth, biological growth media (nutrient broth, terrific broth, tryptic soy broth), and inorganic chemical compounds (mercuric chloride and potassium ferricyanide). First, through adaptive transformation of the sensor outputs, contaminant signals were enhanced and background noise was reduced in time-series plots leading to detection and identification of all simulated contamination events. The improved sensor detection threshold was 0.1% of the background for pH and oxidation–reduction potential (ORP), 0.9% for free chlorine, 1.6% for total chlorine, and 0.9% for chloride. Second, the relative changes calculated from adaptively transformed residual chlorine measurements were quantitatively related to contaminant-chlorine reactivity in drinking water. We have shown that based on these kinetic and chemical differences, the tested contaminants were distinguishable in forensic discrimination diagrams made of adaptively transformed sensor measurements.     

Federal Decentralization and Adaptive Management of Water Resources: Reservoir Reallocation by the U.S. Army Corps of Engineers

Reservoir operations must respond to changing conditions, such as climate, water demand, regulations, and sedimentation. The U.S. Army Corps of Engineers (Corps) can reallocate reservoir storage to respond to such changes. We assembled and analyzed a database of reservoir reallocations implemented and proposed by the Corps. While only a small portion of total reservoir storage nationwide has been reallocated, there are substantial differences in reallocation frequency and magnitude across the nation: some Corps Districts and Divisions use reallocation while others do not, relying more on discretion and small‐scale adaptation of operations. This difference illustrates how water resource agencies like the Corps decentralize management decisions to allow responding to disparate conditions. Decentralized decision‐making provides a responsive approach to water management, while centralized and hierarchical decision‐making is a slower, more deliberative approach. Decentralized decision‐making may lead to the accumulation of short‐term, local decisions over time to the point that the system is managed differently than anticipated. Reallocation, which is a form of planned adaptive management, can be accommodating of multiple competing demands and different stakeholders, yet expensive and less temporally responsive. The challenge for any large water resource management agency is to balance between local‐level, responsive discretion vs. centralized, planned decision‐making.     

Effects of Water Withdrawal From Ice‐Covered Lakes on Oxygen,Temperature, and Fish1

Abstract: In northern regions, large volumes of water are needed for activities such as winter road construction. Such withdrawals, particularly from small lakes, can reduce oxygen concentrations and water levels, potentially affecting aquatic organisms. Withdrawal limits have been developed by regulatory agencies, but are largely theoretical. Water withdrawal thresholds were tested in two small lakes by removing 10% and 20% of their respective under‐ice volumes and comparing oxygen parameters, temperature, over‐wintering habitat, and northern pike (Esox lucius) abundance to reference conditions. Because of a milder winter, oxygen parameters were elevated in reference lakes in the period following withdrawal compared to the prewithdrawal period. The 10% withdrawal resulted in a ?0.2 m shift in the oxygen concentration profile at 4 mg/l in that lake, but had no effect on total volume‐weighted oxygen, or volume of over‐wintering habitat. In contrast, the 20% withdrawal caused 0.7 m reduction in the oxygen concentration profile at 4 mg/l compared to the previous year, a 26% decline in the volume‐weighted oxygen concentration, and a 23% reduction in the volume of over‐wintering habitat compared to prewithdrawal conditions. Water temperatures were slightly (≤ 10%) colder in the upper strata in the year following the withdrawal in both withdrawal and reference lakes. Northern pike abundance was not impacted by water withdrawals in either of the lakes. The results of this study show that the effects of water withdrawal on the parameters investigated reflected the characteristics of the lakes, and would therefore be expected to vary from lake to lake. Policy development to mitigate impacts must therefore reflect the site‐specific nature of water withdrawal.     

滤料级配过滤含聚污水数值模拟研究

以磁铁矿滤料与石英砂滤料为填设滤料层的级配模式一直广泛应用于油田含聚污水处理过程中,但这种滤料级配与污水过滤性能之间的影响关系及规律认识却较为缺乏,本文以悬浮粒子吸附与截留形成的聚集特征为切入,定量分析出水水质特性,对含聚污水过滤过程中滤料级配的影响效果展开数值模拟研究。研究认为：磁铁矿滤料层厚度较大的级配模式过滤具有更好的悬浮粒子吸附与截留效果,对更小粒径悬浮粒子过滤能力更优,但滤料填充高度比与过滤效果存在一定适配性;以1.28以上磁铁矿滤料厚度较大的级配模式过滤较低含聚浓度污水、以1.67以上磁铁矿滤料厚度较小的级配模式过滤较高含聚浓度污水,均可以使出水悬浮固体颗粒与油滴含量均低于5mg/L,满足过滤出水水质指标要求。     

聚合物驱采出水处理工艺研究

聚合物驱油技术在大庆油田得到广泛应用,由于采出水粘度大、油珠粒径小,其处理难度大于油田常规水驱采出水。通过对聚合物驱采出水的特性分析,并在现场分别进行了以横向流除油器(串联DTH聚结器)和水力旋流器为主体的工艺试验。其工艺参数分别为:横向流除油器和DTH聚结除油器的处理量均为85 m3/h,有效停留时间为2.4 h。过滤器为石英砂、磁铁矿双层滤料,处理量为20 m3/h,过滤周期24 h,反冲洗时间为15 min,一次和二次过滤的滤速分别为12 m3/h和8 m3/h。试验结果表明:两种工艺均可代替现有的沉降过滤工艺处理聚合物驱采出水。     

Drainage Impacts on Surficial Water Retention Capacity of a Prairie Pothole Watershed

Wetland restoration has been proposed as a tool to mitigate excess runoff and associated nonpoint source pollution in the Upper Midwestern United States. This study quantified the surficial water retention capacity of existing and drained wetlands for the Greater Blue Earth River Basin (GBERB), an intensively drained agricultural watershed. Using airborne light detection and ranging, the historic depressional storage was determined to be 152 mm. Individual depression analysis suggested that the restoration of most drained areas would have little impact on the storage capacity of the GBERB because the majority (53%) of retention capacity was in large depressions (>40 ha) which comprised only a small proportion (<1.0) of the observed depressions. Accounting for change in storage and the difference in annual evapotranspiration (ET) between wetlands and the croplands that replaced them, restoration of all depressions in the Minnesota portion of GBERB would provide a maximum of 131 mm additional capacity over and above the modern day capacity (193 mm; 56 mm depressional storage; 60 mm wetland ET; and 77 mm cropland ET). Considering that depressional depths in smaller areas are within the range of uncertainty of the lidar digital elevation models and larger depressions have the most storage, we conclude that efforts to increase the surficial water‐holding capacity of the GBERB would be best served in the restoration of large (>40 ha) depressions.     

RECLAIMED WASTE WATER FOR GROUNDWATER RECHARGE1

ABSTRACT. The Orange County Water District has conducted studies in waste water reclamation and groundwater recharge since 1965. The work has been done in three phases: (1) Study in both laboratory and pilot-scale units on the feasibility of reclaiming trickling filter effluent for injection through wells into confined aquifers; (2) long-term injection study to determine the fate of injected reclaimed water and to observe the performance of a multi-casing injection well; (3) testing alternative treatment methods in a 25,000 gpd pilot plant to solve the water quality problems which developed during the injection study. The reclaimed trickling filter effluent was found to be injectable and did not cause excessive well clogging. The multi-casing injection wells performed very satisfactorily. The reclaimed water would be acceptable for domestic use after travel through 500 feet of a confined aquifer in that bacteria, virus and toxic material were consistently absent. However, the odor and taste which persisted in the injected reclaimed water and the high concentration of dissolved inorganics are undesirable characteristics. Methods to eliminate the odor are being tested at the present time. A cooperative project with the Office of Saline Water is under way to develop a source of desalted seawater to blend with reclaimed waste water.     

PERMEABILITY OF AIR AND IMMISCIBLE ORGANIC LIQUIDS IN POROUS MEDIA1

ABSTRACT: The conductivity of air, mineral oil (relative viscosity 77), and a light nontoxic oil (relative viscosity 4.7) was measured in three porous media: a sand, loamy sand, and a silt loam. The measurements were made over a range of water contents for each porous medium. Small volumes of air were present as well as significant amounts of water during most of the oil conductivity measurements. The results were compared to two methods for calculating conductivities of immiscible fluids in water-wet porous media. A new equation that accounts for swelling and for the gas slippage effect in very small pores was formulated for use with these methods The observed conductivities, spanning seven orders of magnitude, agree reasonably well with calculated values. Only three soil parameters are required to calculate the conductivities: (1) the saturated conductivity of water, (2) the saturated conductivity of the immiscible fluid of interest, and (3) a pore size index value that is obtained from an estimate from the water release curve of the porous material. Remediation of organic liquid spills is briefly discussed to illustrate the practical applications of gas phase conductivities, as well as those for immiscible organic liquid phases. It is concluded that, in light of spatial variation under field conditions, the method presented for calculating values of three-phase conductivities will be useful in the management of immiscible organic liquid spills and leaks.     

CONFLICT AND COOPERATION OVER INTERNATIONAL FRESHWATER RESOURCES: INDICATORS OF BASINS AT RISR1

ABSTRACT: In this paper we seek to identify historical indicators of international freshwater conflict and cooperation and to create a framework to identify and evaluate international river basins at potential risk for future conflict. We derived biophysical, socioeco‐nomic, and geopolitical variables at multiple spatial and temporal scales from GIS datasets of international basins and associated countries, and we tested these variables against a database of historical incidents of international water related cooperation and conflict from 1948 to 1999. International relations over freshwater resources were overwhelmingly cooperative and covered a wide range of issues, including water quantity, water quality, joint management, and hydropower. Conflictive relations tended to center on quantity and infrastructure. No single indicator—including climate, water stress, government type, and dependence on water for agriculture or energy—explained conflict/cooperation over water. Even indicators showing a significant correlation with water conflict, such as high population density, low per capita GDP, and overall unfriendly international relations, explained only a small percentage of data variability. The most promising sets of indicators for water conflict were those associated with rapid or extreme physical or institutional change within a basin (e.g., large dams or internationalization of a basin) and the key role of institutional mechanisms, such as freshwater treaties, in mitigating such conflict.     

Dissolution kinetics of heavy metals in Dutch carbonate- and sulfide-rich freshwater sediments

In two sulfide-rich freshwater sediments from the Biesbosch and Kromme Rijn River in the Netherlands differing in carbonate content and acid volatile sulfide (AVS) content, metal and sulfide dissolution kinetics were studied at different acid concentrations by varying both the procedure of acid addition and the extraction time. The establishment of equilibrium was monitored by measuring the pH in time, which reached a near constant value. The equilibrium pH was reached quickly when large amounts of acid were added and slowly when small amounts of acid were added. This observation was confirmed by the yield of extracted metals after either a 45-min or 24-h extraction over a pH range from 0 to 5. The pH factor seemed to be of more influence than time for the dissolution of metals. The amount of extracted metals was highly dependent on the metal itself due to its physico-chemical behavior. Although the sediments studied varied in carbonate content, acid volatile sulfide (AVS), and total metal content, the extracted fraction of metals compared with their total content in the sediment was similar for most metals. Finally, the AVS content as well as the ratio of simultaneously extracted metals (SEM; sum of Cd, Cu, Ni, Pb, and Zn) to AVS decreased with increasing pH. Because the SEM to AVS ratio may be used to set environmental quality criteria for the sediment compartment, this observation is of significance.     

Crushed concrete as a phosphate binding material: a potential new management tool

To avoid eutrophication of receiving waters, effective methods to remove P in urban and agricultural runoff are needed. Crushed concrete may be an effective filter material to remove dissolved and particulate P. Five types of crushed concrete were tested in the laboratory to evaluate the retention capacity of dissolved P. All types removed P very effectively (5.1-19.6 g P kg(-1) concrete), while the possible release of bound P varied between 0.4 and 4.6%. The retention rate was positively related to a decreasing concrete grain size due to an increasing surface area for binding. The P retention was also related to a marked increase in pH (up to pH 12), and the highest retention was observed when pH was high. Under these circumstances, column experiments showed outlet P concentrations <0.0075 mg P L(-1). Furthermore, experiments revealed that release of heavy metals is of no importance for the treated water. We demonstrate that crushed concrete can be an effective tool to remove P in urban and agricultural runoff as filter material in sedimentation/infiltration ponds provided that pH in the treated water is neutralized or the water is diluted before outlet to avoid undesired effects caused by the high pH.     

WATER SUPPLY COSTS FOR SMALL PRIVATE UTILITIES1

ABSTRACT: This paper examines the cost of water supply for small and mid-sized private water utilities. An econometric approach was employed in which data on utility costs and characteristics were used to estimate a total water supply cost function from which average and marginal costs were derived. The results suggest that although average and marginal costs decline with output, the rate of decline rapidly approaches zero, and unit costs therefore appear to remain relatively constant over a wide range of output. Implications of the results for pricing policy are examined.     

DISINFECTION WITH QUATERNARY AMMONIUM COMPOUNDS1

ABSTRACT: The most common disinfection method is chlorination, however, it has been known that the practice of chlorination for water treatment in the Mississippi River area has caused a significant increase in mortality. The objective of this research was to search for effective disinfectants to replace chlorine. Three cationic surfactants have been tested for their bactericidal properties under various conditions. It has been found that 1 mg of cetyldimethyl-benzylammonium chloride can destroy about 4500 coliforms in one liter water within 10 minutes, under neutral pH conditions and room temperature. Cationic quaternary ammonium compound, therefore, can be a potential candidate disinfectant for replacing chlorine when necessary.     

Measuring the Net Economic Value of Recreational Boating as Water Levels Fluctuate1

Abstract: The purpose of this article was to show how the value of recreational boating can be assessed and how that value can be linked to water levels. Data were gathered via a survey of recreational boaters to determine days boated and willingness‐to‐pay (net economic value) for boating on Lake Ontario and on the St. Lawrence River in 2002. Depth measurements were taken at marinas and yacht clubs, boat launch ramps, and private docks. Stage‐damage curves were used to pinpoint at what water levels and to what extent boaters would be impacted. Boaters recreated an estimated 1.3 million days in 2002 and spent an estimated US$178 million in New York counties bordering Lake Ontario and the St. Lawrence River. The mean net economic value per day per boat (above current expenditures) was $69.36, with an estimated total net economic value of US$90 million. Using Lake Ontario as an example, the stage‐damage curves show that the overall negative impact would be small, between 245 and 248 ft. Maintaining water levels within that range for the entire boating season would be ideal for Lake Ontario boaters and associated businesses.     

电化学氧化处理焚烧厂渗滤液膜浓缩液混凝出水的研究

为了降低城市生活垃圾焚烧厂渗滤液膜浓缩液混凝出水中的有机物浓度,采用电化学氧化对渗滤液膜浓缩液混凝出水进行了处理.同时,考察了阳极材料、电流密度、初始pH值和电解时间对有机物的去除影响,使用三维荧光光谱分析了有机物的去除特性,并通过氯离子的转化探讨了有机物的降解机理.结果 表明,钌铱(Ru-Ir/Ti)阳极对有机物的去...