Water Treatment Standards For Small And Medium Water Supply And Water Quality

This paper is based on the example of primary water-supply plant placed in Yuhuan. It investigated what measures should be taken for a qualified water-supply in small and medium-sized water plants.Yuhuan is an island country in Zhejiang Province, where the average annual precipitation is low as1460.3mm. The water source for water plants there is almost reservoirs. Unfortunately, reservoirs in Yuhuan always suffer water shortage because of climate and geography. Even worse, there exist many industries and living quarters around reservoirs. All of those make it difficult to supply qualified water to people in long-term. In2006, the requirement for water-supply was enhanced as a new national standard was issued. Now previous crafts is not enough to meet the requirement for safely portable water. Therefore, it is a serious need to reform and optimize previous crafts.The paper is aim to get series of effective crafts corresponding to water samples of different physic-chemical properties. For the purpose, we made a systematical record about previous crafts and water quality changes in recent years in Yuhuan. A lot of experiments and evaluation on stability of long-term operation were also conducted. According to practical situation in water-supply plants, pharmaceutical formulations were optimized and treatment crafts were reformed in some plants to improve quality and long-term stability.We start with analysis about water properties in different stages. Then an emphasis was put on improvement of treatment and the results were evaluated in detail. A long-term operation evaluation exhibited wonderful achievements as a result of water plants reconstruction in Kanmen, Chumen, and Qingan as well as partly reformation of treatment procedure in Litun, Chenyu, Chengguang, and Lupu. In addition, we set up a treatment procedure removing manganese and ammonia by adding potassium permanganate and reactive chloride, respectively. All of those works is significant to further improvement in water quality and portable water safety.