非洲部分地区饮用水水质及天然絮凝剂应用现状

Application Situation of Natural Flocculants and Drinking Water Quality for Water Supply in Some Areas of Africa

文中介绍了非洲的饮用水水质现状和几种广泛使用的天然絮凝剂。目前大部分非洲居民仍将地下水、河水、雨水等作为直接饮用水,而这些水的浊度、色度、重金属、大肠菌群、有机物含量等均存在不同程度的超标现象,造成非洲儿童死亡率居高不下。为改善饮用水水质,辣木、黏土等天然絮凝剂在非洲低供水率地区(尤其是农村)得到广泛应用,主要用于降低水体浊度(去除率一般大于80%)。部分絮凝剂有杀毒灭菌、降低硬度、去除重金属的作用。但是,大部分天然絮凝剂存在用量大、絮凝效果差、有机物去除率低、生物指标不达标、使用方法不科学等一系列问题。因而,天然絮凝剂的进一步研究和优化对提高非洲居民饮用水水质具有很大意义。

Drinking water quality and several widely used natural flocculants in some areas of Africa are introduced. At present, lots of people drink groundwater, river water or rain water directly which cause the high mortality of African children, for the turbidity, color, concentration of heavy metal, coliforms and organic matters of these water unable to meet the standards. In order to improve the quality of drinking water,natural coagulants including moringa and soils are widely used in Africa, especially in rural areas, to remove the turbidity of the water （the removal efficiency 〉 80% ）. In addition,some of the natural flocculants can help to sterilize bacteria,soften hardwater and remove heavy metals. However,there are some shortcomings of natural flocculants including high dosage,low removal efficiency of organic matters,introducing bacteria and improper usage. Therefore,it is important to have more detailed study on natural flocculants in order to improve the drinking water quality in Africa.