The water treatment technology can be classified in two major categories of water treatment and wastewater disposal . both depend on physical , chemical and biological operations and processes to remove the un - wanted substances or pollutants to achieve the objective of purifying the water quality 水的处理大概可分为用水处理及废污水处理两大部分，不论是用水处理或是废污水处理，主要是藉由物理、化学及生物等作用，将水中不要的物质或是污染物移除，而达到净化水质之目标。
At present , there are so many researches and practices about water resources sustainable utilization in home and abroad . these researches and practices are all reflecting the ideas of ecology - economy system . they consider water resources utilization is not only from economic aspect but also from aspect of possible effect on ecologic enviroment . lt should make human being harmonize with nature . during earring out water resources sustainable utilization , we should not only shift supply management to demand management and take measures to save water and improve the efficiency of water utilization , but also mobilize the enthusiasm of water usersjet them join in water resources management , that is to say , let them join in exploiting and utilization of water resources and discharging waste water 目前，国内外对水资源持续利用的研究和实践还是很多的。这些研究和实践里都渗透着生态经济系统的理念，即不仅从经济的角度考虑水资源的利用，而且更应从可能对生态环境产生的影响来考虑水资源的利用，使人与自然相协调。在实现水资源的持续利用中，不仅要实现从供给管理转向需求管理，采取各种方法节约用水，提高用水的效率，而且还应该充分调动水用户的积极性，使他们参与到对水的管理中，对水资源的开发、利用以及废污水的排放都进行全面的参与。
