【正文】 MF membranes have been used in a fullscale facility for the treatment of produced water . Product water from this treatment was reported to be free of suspended solids and nearly all nondissolved anic carbon . Ceramic UF/MF membranes can operate in both crossflow filtration and deadend filtration modes and have a lifespan of 10 years. Chemicals are not required for this process except during periodic cleaning of membranes and precoagulation (used to enhance contaminants removal). Reverse osmosis and nanofiltration RO and NF are pressuredriven membrane processes. Osmotic pressure of the feed solution is suppressed by applying hydraulic pressure which forces permeate (clean water) to diffuse through a dense, nonporous membrane . Seawater RO can remove contaminants as small as 181。m. It is applicable for treating water containing TDS in the range of 500–25 000 ppm. This technology is similar to RO. NF membranes were employed for produced water treatment on both bench and pilot scales. Mondal and Wickramasinghe studied the effectiveness of NF membranes for the treatment of oilfield produced water. Results showed a minimal improvement when pared with the effectiveness of brackish water RO treatment of the same feed water. Thermal technologies Thermal treatment technologies of water are employed in regions where the cost of energy is relatively cheap. Thermal separation process was the technology of choice for water desalination before the development of membrane technology. Multistage flash (MSF) distillation, vapour pression distillation (VCD) and multieffect distillation (MED) are the major thermal desalination technologies . Hybrid thermal desalination plants, such as MED–VCD, have been used to achieve higher efficiency . Although membrane technologies are typically preferred to thermal technologies, recent innovations in thermal process engineering make thermal process more attractive and petitive in treating highly contaminated water. Multistage flash MSF distillation process is a mature and robust technology for brackish and sea water desalination. Its operation is based on evaporation of water by reducing the pressure instead of raising the temperature. Feed water is preheated and flows into a chamber with lower pressure where it immediately flashes into steam. Water recovery from MSF treatment is ～20% and often requires posttreatment because it typically contains 2–10 mg/l of TDS. A major setback in operating MSF is scale formation on heat transfer surfaces which often makes this process require the use of scale inhibitors and acids. Overall costs vary depending on the size, site location and materials of construction . Its energy requirement is between and kWh. Globally, MSF market share has significantly decreased due to petition of membrane technologies, but it is a relatively costeffective treatment method with plant life expectancy of more than 20 years, and can be employed for produced water treatment . Multieffect distillation MED process involves application of sufficient energy that converts saline water to steam, which is condensed and recovered as pure water. Multiple effects are employed in order to improve the efficiency and minimize energy consumption . A major advantage of this system is the energy efficiency gained through the bination of several evaporator systems. Product water recovery from MED systems are in the range of 20–67% depending on the type of the evaporator design employed . Despite the high water recovery from MED systems, it has not been extensively used for water production like MSF because of scaling problem associated with old designs. Recently, falling film evaporators have been introduced to improve heat transfer rates and reduce the rate of scale formation . MED has a life cycle of 20 years and can be applied to a wide range of feed water quality like MSF. It is good for high TDS produced water treatment . Scale inhibitors and acids may be required to prevent scaling and pH control is essential to prevent corrosion. Power energy consumption is in the range of – kWh, operating cost is $ total unit cost is $. Vapour pression distillation VCD process is an established desalination technology for treating seawater and RO concentrate [. Vapour generated in the evaporation chamber is pressed thermally or mechanically, which raises the temperature and pressure of the vapour. The heat of condensation is returned to the evaporator and utilized as a heat source . VCD is a reliable and efficient desalination process and can operate at temperatures below 70176。其他治療方法 ,如。 盡管原始數(shù)據(jù)仍然沒有公開可用的 ,總結的官方報告顯示 ,%的農(nóng)村家庭煮水喝 ,治療前 %他們的水 (不含沸騰 )。這些調查結果已經(jīng)被包括在世界衛(wèi)生組織 /聯(lián)合國兒童基金會聯(lián)合監(jiān)測項目報告。s Fund Joint Monitoring Program report. However, none of these survey questionnaires covered household water treatment. Despite the lack of data on home water treatment accessible in the English language, it is possible that other surveys exist that have been conducted by the Chinese government rather than through international systems, such as the Multiple Indicator Cluster Survey, with results published in Chinese only. We searched the bibliographic database Chinese National Knowledge Infrastructure by using the Chinese key words for “household” and “water” and “treatment/disinfection”. We found 417 Chinese language references. After screening the titles and abstracts of all references and the content of an additional 197 references, we found one paper reporting the national summary results of the Investigation of Drinking Water and Sanitation in the Rural Areas conducted jointly by the Ministry of Health and the National Committee for Patriotic Public Health Campaign, People39。 a 我們找遍了整個中國國家知識基礎設施的書目數(shù)據(jù)庫使用中國關鍵字為“家庭”和“水”和“治療 /消毒”。雖然沒有報道家庭調查數(shù)據(jù)為城市地區(qū) ,一份報告估計 ,3 5%的城市人口使用家庭水過濾器。它進一步凸顯了需要的羅莎和 Clasen 理解的效果和使用沸騰在不干涉的設置