Abstract:
Large amounts of sludge produced in water supply system and inappropriate sludge draining time causing sludge compacting, sludge clogging and losses of a lot of water to drain. This experiment collected data on water production system, raw water quality and chemical consumption from water supply plants PWA (branch Kokha, Prae and Banhong) to assess sludge accumulation and appropriate sludge management. The results showed that the amount of sludge accumulation in the sedimentation tank of PWA (branch Kokha, Prae and Banhong) were increased in the rainy season and decreased significantly after the rainy season was over. The average daily sludge incidence in 2019 (120.09, 2,826.71 and 25.23 kg/d) and 2020 (121.28, 2,593.10 and 127.41 kg/d) was similar. The study found that the most suitable time for sludge drainage at 1 time / week. Resulting in high efficiency for production system, saving operating resources and less effecting on production process or water quality. Sludge accumulation of water production from 3 raw water sources namely the Yom River (Phrae branch), Wang River (Ko Kha branch) and Li River (Banhong branch). The amount of sediment that occurred in 2019 (1,022.78 43.00 and 4.63 m3) 2020 (915.37 43.26 and 22.92 m3 ) was similar and the sludge incidence rate was 896.08 43.13 and 13.73 m /year. The sludge storage ponds supported the sediment that has been formed was 9.34 1.86 and 1.43 % respectively, and the remaining volume that could accommodated sediment was 81.32 98.14 and 98.57 % respectively. As a result, the sludge storage ponds must be dredged after a period of 5, 5 and 5 years respectively.