九龙江流域水厂生产废水回用条件的初步研究

Primary research on waterworks wastewater reuse in Jiulongjiang River Basin Waterworks

以九龙江原水为研究对象,从改善低浊水混凝条件优化净水工艺角度,对生产废水的回用条件和作用规律进行了研究。研究认为:回用具有适当含固率的生产废水可以改善水处理过程的混凝条件,节省投药量,节药率一般为10%～40%;存在改善混凝条件、节省投药量的最佳含固率和最佳混合水浊度范围,最佳含固率为0.1%～0.7%,最佳混合水浊度为60～400NTU;原水浊度是显著影响最佳含固率的因素。当原水浊度小于60NTU时,最佳含固率随原水浊度的升高而增加,当原水浊度大于60NTU时.最佳含固率随原水浊度的升高而降低,最佳混合水浊度表现出相同的规律;在生产过程中,建议以最佳混合水浊度控制生产废水的回用。

The water recycling condition and working mechanism of waterworks wastewater reuse were studied. The coagulation operation has been just optimized to improve the effects in purification of low turbidity raw water taken from Jiulongjiang River. The results showed that recycling of wastewater with suitable solid content could improve the coagulation condition and save coagulants about 10%~ 40%. There were optimal ranges for wastewater solid content (0.1% to 0.7%) and for mixed water turbidity (60 to 400 NTU). The turbidity of the raw water was dominating factor affecting the optimal solid content. When the turbidity of raw water was less than 60 NTU, the optimal solid content ratio increased with raw water turbidity, while when raw water turbidity was more than 60 NTU, the optimal solid content ratio decreased with raw water turbidity. The optimal mixed water turbidity behaved same. In potable water production process, it was suggested in this paper that optimal mixed water turbidity could be selected as parameter to control the wastewater recycling.