The quality of the water supply is the key to ensuring the success of the water supply project. According to the "Technical Essentials of Rural Water Supply Engineering", the quality of its water supply should meet the relevant requirements of the "Sanitary Standards for Drinking Water". The water quality purification treatment of centralized water supply projects can reasonably adopt water purification technology, water purification structures or water purifiers according to the specific conditions of each region. For groundwater with good water quality, only disinfection treatment can be performed; for sources of raw water whose turbidity does not exceed 20 degrees for a long time, and which does not exceed 60 degrees for an instant, or surface water whose turbidity does not exceed 20 degrees after pretreatment, direct filtration and disinfection can be used. For the water treatment process, slow filtration or contact filtration can be used for filtration; the turbidity of raw water does not exceed 500 degrees for a long time, and surface water that does not exceed 1,000 degrees for an instant can use conventional water treatment processes such as coagulation, sedimentation, filtration and disinfection. When the seasonal variation of the sand content of the raw water is large or the turbidity often exceeds 500 degrees, pretreatment should be performed first, followed by conventional water treatment to reduce water treatment costs and the difficulty of operation and management; the sand content of the raw water changes greatly or the turbidity When it often exceeds 1000 degrees, pre-settling measures can be taken before the conventional water purification process; high turbidity water should be purified according to the requirements of "Design Specification for High Turbidity Water Feedwater".
(1) Full-automatic water purification equipment For self-pressure water supply projects with reservoirs as water sources, the water quality is generally turbidity exceeding the standard, E. coli exceeding the standard, and nitrate exceeding the standard. High-efficiency automatic water purification equipment can be used, equipped with automatic dosing devices and Disinfection device, built a water purification plant with a full set of functions. The water purification device integrates processes such as flocculation, sedimentation, sewage discharge, centralized filtration, and disinfection, and has the advantages of good treatment effect, excellent water quality, small footprint, water saving, power saving, labor saving and the like.
(2) Disinfection measures Disinfectants for domestic drinking water generally use liquid chlorine, sodium hypochlorite, chlorine dioxide, bleaching powder, etc. Water plants with smaller water distribution networks can use ultraviolet disinfection. Disinfectant should be added after filtration. When there is more organic matter and algae in the raw water, it can be added before coagulation sedimentation and after filtration. Pipes and fittings to which disinfectant is added shall be made of non-toxic and corrosion-resistant materials. The fixed reserve of the disinfectant warehouse should be calculated according to the local supply and transportation conditions, based on the maximum usage of 15 to 30 days, and its periodic reserve should be determined according to the specific local conditions.