粒状滤料过滤技术发展与应用的探讨

粒状滤料过滤技术广泛用于废水的深度处理.过滤技术使用后,快滤池技术发展迅速.随着多种滤料的开发,深层过滤技术得到发展,直接过滤工艺应运而生.反冲洗是快滤池的一项关键技术,气水联合反冲洗对滤料过滤能力的再生效果优于单水反冲洗.滤料过滤存在跑料、料层板结等问题,在工程实践中逐步得到改进.     

核桃壳滤料用于处理含油、含浊废水的试验研究

通过试验研究，证明核桃壳滤料用于预处理后洗井废水的过滤是合适的。同时确定了不同粒径滤料的反冲洗强度、冲洗时间和反冲洗效果的关系。     

电脱盐反冲洗废水稳定性研究

电脱盐反冲洗废水污染组成复杂,废水乳化带油严重,破乳分离困难。文章对比分析了电脱盐反冲洗废水与正常排水的水质特性,通过Zeta电位、表面张力和稳定性分析探究了体积稀释比对反冲洗废水稳定性的影响,考察了不同体积稀释比及转速与电脱盐反冲洗废水沉降或上浮速率的关系。结果表明：电脱盐反冲洗废水COD为55 785 mg/L,是正常排水的10.8倍,以非溶解性有机物为主;反冲洗废水Zeta电位为-2.5 mV,当体积稀释比为90%时,Zeta电位为-14.8 mV,随着体积稀释比降低,Zeta电位稳定在-14～-18 mV;反冲洗废水表面张力为42.20 mN/m,体积稀释比由100%变化至70%时,表面张力变化不大,但随着体积稀释比降低,表面张力呈增加趋势;反冲洗废水的不稳定性指数约为0.05,当体积稀释比从90%变化至1%时,不稳定性指数升高,而且转速由500 r/min增加至1 000 r/min时,不稳定性指数也有所升高;电脱盐反冲洗废水体积稀释比为80%～90%时,适于上浮处理;体积稀释比为20%～40%时,适于沉降处理。研究成果可为电脱盐废水混凝脱稳与气浮沉淀分离处理提供参考。     

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。     

无阀滤池在丁腈橡胶污水处理中的应用

研究利用砂滤技术去除丁腈橡胶污水携带橡胶胶粒的问题,首先通过筛分实验确定橡胶胶粒的粒径分布区间,理论计算过滤该粒径区间橡胶胶粒所需的石英砂滤料粒径范围和填装高度,再利用小试验证砂滤技术去除橡胶胶粒的技术可行性并确定关键的滤料参数和反冲洗周期,最后以石英砂作为无阀滤池的滤料在丁腈橡胶污水处理装置进行工业化应用。发现采用两层不同粒径,总厚度为500mm的石英砂作为无阀滤池滤料,可彻底去除丁腈橡胶污水中的细小胶粒和其它悬浮物,应用效果良好。     

气水反冲洗工艺提高油田采出水过滤器再生效果

油田采出水中含有的聚合物容易导致颗粒滤料类过滤器中的滤料颗粒黏度升高、附着力增强,甚至形成板结块和滤饼层,难以通过单一的反冲洗方式进行再生.通过试验研究确定使用气水反冲洗再生技术,可有效地解决目前油田实际生产中存在的颗粒滤料污染后再生困难的技术难题,提高过滤后的水质,使滤后水质稳定达标,适应油田开发后期水质发生变化的特点.     

新疆油田压力式连续流过滤器工业性试验

介绍了压力式连续流过滤器用于油田采出水的工业性试验,试验结果表明:采用0.8～1.2 mm石英砂滤料处理水质悬浮物,73.7%情况下出水悬浮物可降至2 mg/L以下,26.3%情况下出水悬浮物可降至2～5 mg/L,水质介于一级与二级过滤指标要求之间,处理水质较双滤料过滤器出水水质好;采用0.5～0.8 mm金刚砂滤料,处理水质悬浮物在5～6 mg/L,含油在1 mg/L以下。     

粒状滤料过滤理论浅析

粒状滤料过滤理论的主要内容是过滤机理、过滤方程式和反冲洗机理。过滤机理有悬浮颗粒的迁移机理、悬浮颗粒的吸附机理和脱落机理等。过滤在水澄清的同时，滤层的水头损失增加，整个过程涉及因素多而且复杂，过滤方程式很难得到解析性的答案，所以过滤方程对过滤过程只起定性的作用。现在反冲洗机理的研究认为，悬浮颗粒从滤料表面脱落是水流剪切和颗粒碰撞综合作用的结果。     

水淬渣处理废水的研究进展

水淬渣的微观结构特殊,比表面积大,表面能高。国内外研究表明,水淬渣吸附去除废水中的Cu2+、Zn2+、Ni2+、Pb2+、Cr6+、As3+及磷等效果良好,而且对废水中的COD、大分子有机物、油类、苯酚等也有比较好的去除率;并研究了吸附去除的机理,对水淬渣在水处理领域的应用起到了推动作用。     

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。     

Three-dimensional field studies of thermal backwashing plumes

Using specially designed temperature profiling equipment, two surveys were conducted during thermal backwashing operations at Pilgrim Nuclear Power Station to determine the spatial and temporal extent of temperature rises above ambient. Thermal backwashing is a process where biofouling is combated by a heat treatment procedure. Backwashing formed a thermal plume about 5- to 6-ft thick (1.5- to 1.8-m) in front of the intake screenwall. Maximum observed surface temperatures were 101.0°F (38.3°C), representing a rise (T) of about 43.4°F (24.1°C) above ambient. The frontal zone of the plume spread gradually seaward at about 0.2 kn. Its outer edge became thinner and rapidly cooled, presumably by advection and turbulent diffusion associated with currents from the reverse pumping and local changes from dissipation to the atmosphere. Along the intake shoreline, the plume was often less than 1 ft (0.3 m) thick. Most of the hot water was dissipated within several hundred feet of the intake with Ts of about 10.0 to 15.0°F (5.6 to 8.3°C) above ambient. Under the influence of 15 mph southwesterly winds during the second survey, some warmed water was apparently carried beyond the outer breakwaters into Cape Cod Bay. These surveys provided real-time data indicating that the backwashing operation caused a relatively thin thermal plume, which spread rapidly from the intake out across the study area and along the seaward breakwater. Within a few hours these backwash thermal plumes were completely dissipated.Formerly affiliated with Normandeau Associates, Inc., Bedford, New Hampshire.     

次氯酸钠药剂在不同水厂的应用

次氯酸钠药剂在水务行业应用广泛,常被用作消毒剂,对于保障水质具有重要的作用。介绍了近6年来次氯酸钠消毒剂在水务行业的应用情况,以期为不同性质水厂的运行提供参考。     

PUBLIC PERCEPTIONS IN WATER QUALITY EVALUATION1

ABSTRACT: A Visual Perception Test, consisting of photographic slides of water sites, was designed to examine laymen's water quality perceptions. The slides were taken at five water sites where the level of visual pollution was artifically altered by the investigator. Analysis of variance indicated that the water sites were evaluated differently for each of five pollution levels. Increases in water discoloration and the quality of litter were viewed as increases in level of pollution. Laymen not only evaluated visually polluted sites lower for uses such as picnicking, but they also evaluated the quality of the actual water lower. Stepwise multiple regression indicated that a combination of water color, scenic beauty appreciation, quality of the surrounding environment and industry as a pollution source explained 73 percent of the variance in predicting Overall Pollution. Application of factor analysis simplified the variables to an Overall Pollution Factor and a Boating Use Factor.     

THE W-INDEX FOR RESIDENTIAL WATER CONSERVATION1

ABSTRACT: An index of residential water efficiency - a “W-Index” - can serve as a measure of effectiveness of water conservation features in the home. The index provides a calculated numerical value for each dwelling unit, derived from the number and kind of water-saving features present, including indoor and outdoor water savers and water harvesting or recycling systems. A W-Index worksheet, devised for on-site evaluation of single-family residences in the Tucson, Arizona, region shows that a nonconserving residence with all the water-using features would use 151,000 gallons per year or 148 gallons per capita per day (gpcpd), while the fully conserving model would use 35,300 gallons per year or 35 gpcpd and with water harvesting and graywater recycling systems would have a maximum W-Index of W-160. A Tucson water conservation demonstration home, Casa del Agua, received a rating of W-139, and field tests of about 30 homes in new Tucson subdivisions show values ranging from W-75 to W-100, indicating the incorporation of some water conservation in current new models. By adjustment of some climatic or water-use parameters, the W-Index format can be applied to various types of dwelling units or to other urban areas. The W-Index can be used by individual homeowners or builders to evaluate water efficiency of residential units, or by water providers or water management agencies as a device for promoting and achieving water conservation goals.     

RATIONAL INDUSTRIAL WATER REUSE RATIOS1

ABSTRACT: This work begins by defining rational water use, and then discusses important factors that most strongly influence it. A general model is then developed to enable factories to quantify the ratio of rational industrial water reuse based on the least cost method. The model is established to minimize the cost of water with reference to gross water use and three subsystems ‐ the intake, reuse, and discharge of industrial water. Discharge cost is determined using data from a 1997 survey of 38 factories, and reuse costs are ranked and expressed by a step function. The model is verified using data from a typical semiconductor factory in northern Taiwan's Hsinchu Science Based Industrial Park, whose effective rational water reuse ratio is about 38 percent. A sensitivity analysis shows that improving water reuse technology is the most important factor in determining the rational water reuse ratio, and the price of water is the second most important. When water costs over NT$30 (New Taiwan Dollar, US$1 = NT$34) per cubic meter, increasing reuse becomes significant. The model provides a step towards the scientific management of industrial water.     

The Water Market for the Middle and Lower Portions of the Texas Rio Grande Basin1

Leidner, Andrew J., M. Edward Rister, Ronald D. Lacewell, and Allen W. Sturdivant, 2011. The Water Market for the Middle and Lower Portions of the Texas Rio Grande Basin. Journal of the American Water Resources Association (JAWRA) 47(3):597‐610. DOI: 10.1111/j.1752‐1688.2011.00527.x Abstract: Regional water management on the United States’ side of the middle and lower portions of the Rio Grande basin of Texas has been aided by a functioning water market since the early 1970s. The water market operates over a region that stretches from the Amistad Reservoir to the Rio Grande’s terminus into the Gulf of Mexico. This article provides an overview of the organizations, institutions, policies, and geographic particulars of the region’s water‐management system and its water market. In recent years, this region has experienced high population growth, periodic droughts, and a reallocation of water resources from the area’s agricultural sector to the municipal sector. Demand growth for potable water and a relatively fixed supply of raw water are reflected in increasing prices for domestic, municipal, and industrial water rights. Rising prices in the presence of scarcity and the transfer of water from lower‐value to higher‐value uses indicate that the market is operating as suggested by economic theory. Reasons for the market’s functionality are presented and discussed. Finally, suggestions are presented which might mitigate potential complications to market operations from aquifer depletion and aid the management of instream river flows.     

MEETING FUTURE PUBLIC WATER SUPPLY NEEDS: A SOUTHWEST PERSPECTIVE1

ABSTRACT: Most southwestern cities were founded along rivers or in areas having springs or readily available ground water. Because of the generally sparse precipitation, the renewable fresh water supply in the Southwest is smaller than most other areas of the United States. Despite the arid climate, water use has increased rapidly, first in the form of irrigation, and more recently the use in cities. This has caused extensive development of local water resources and overdraft of ground water basins in some areas. It is difficult to implement new local supplies and importation projects due to a myriad of environmental and legal constraints and a general shortage of public funds. Various opportunities and plans for water management, both on the demand and supply sides, are discussed. Evolving water strategies in four metropolitan areas - El Paso, Albuquerque, Las Vegas, and Phoenix - and issues regarding the Central Arizona Project are presented.     

水资源短缺的有效解决途径——虚拟水战略

针对中国水资源利用现状，系统论述了水足迹、虚拟水以及虚拟水战略的概念和内涵。通过水足迹来揭示人类对水资源的实际需求和占用，介绍了虚拟水战略的研究展望及存在的不足，通过应用虚拟水战略可以缓解水资源短缺现状，保证水资源与人口、耕地的地域组合均衡。