WHO claimed that the world has met the Millennium Development Goal target of halving the proportion of people without sustainable access to safe drinking water in 2012, but there are still 783 million people living in rural areas lacking safe drinking water.1 This means that more than 783 million tonnes of safe drinking water is needed to be produced to solve this problem (assuming one person drinks 3 L of water every day).
WHO认为在2012年世界上一半的人已经有安全的饮用水了。但是，还有近八亿在乡村的居民没有安全的饮用水。
In three countries, Bangladesh, Benin, and Cambodia (covered in a report by the World Bank), 46 million people lack access to clean water. The problem costs these countries 0.2–0.7 percent of gross domestic product (GDP) a year—at least US$275 million in total.
在孟加拉国，贝宁和柬埔寨，因为缺乏干净的饮用水，每年至少有0.2到0.7%的GDP被消耗掉。
For those people, the main enemy against safe drinking-water is about two dozen infectious diseases predominantly caused by fecal microorganism contamination of the water source.3 The minimum infectious doses for average healthy adults range from just a few organisms for Salmonella typhi (typhoid causing bacteria), to several hundred organisms for Shigella flexneri (dysentery-causing bacteria), and to several million cells of Vibrio cholera (cholera-inducing cells).4 These doses are significantly lower for infants and small children than for the general adult population.4
对这些人来说，水中的细菌是他们最大的威胁。
A big step taken by the Chinese government is connecting every rural village with sophisticated water distribution systems. Despite the apparent advantages a water distribution system could bring, there are many downsides it might encounter. The high construction investment of a water distribution system, the great amount of energy required by the pumping process, and the high maintenance cost will limit the wide application of this approach around the world. Even if all those problems are solved, almost 40% of water brought to the household will be used for toilet flushing, which is a huge waste. Not to mention that a water distribution system with proper maintenance could have 10 to 20% leakage.5 More importantly, it could bring secondary biological or chemical contamination if the distribution process is not well designed or monitored.6
中国政府在乡村建设了很多小型饮用水处理供应站，花费了巨额投资，也同时需要巨额运营费用。然而，处理出来的水大约有20%都因为管道漏水而漏掉，同时也因为运营人员的素质不高，水质没法得到保证。在水质没法保证但是使用者们都相信水已经得到处理的时候，疾病更容易滋生。
An ultrafiltration POU system usually has very high removal efficiency of turbidity and more than 99.99% kill of bacteria.7 However, it does not reject many of natural organic and inorganic compounds in water, resulting in less possibility of fouling of the filter. Therefore, the capital and maintenance cost of ultrafiltration filter could be lower. In addition, the development of the materials and the fabrication process could further reduce its cost.
超滤膜系统可以阻挡99.99%的细菌和病毒，同时也因为比较不容易被堵塞，使用寿命会比较长，从而降低了使用费用。
In some cases, microbial contamination in water is not the only problem. Water source can be contaminated by harmful natural minerals, industrial wastewater, or landfill leachate. Simple units including pre-treatment enhanced ultrafiltration POU systems could not guarantee the water quality. Other treatment processes should be implemented. But the cost for treating water will significantly increase. In these cases, when the cost is too high, reaching for a new water source is necessary.
但是，有时候重金属的污染是没法用超滤膜除去的。在这种情况下，就可以加上一些其他的处理设备。
you are welcomed to buy low-price high-quality treatment unit from me.
打个广告，可以跟我买便宜又实用的家用水处理设备。