Experimental Research For Disinfected Methods In The Course Of Wastewater Reuse

As the short of the water resources, wastewater discharged from municipal wastewater plant is used as the source of the reused water or used to dilute rivers and lakes more and more, and this method had been accepted by people. But wastewater always takes plenty of pathogens so it has to be disinfected before reuse.Now, wastewater disinfection in our country is at underway phase. Disinfection cells of some municipal wastewater plants do not run because of the cost and safety factors. We knowledge about wastewater disinfection rests on wastewater disinfection application of foreign countries and small-experimens of our country.Toward the secondary sewage effluents of YanTian plant, plenty of experiment on disinfection with chlorine,chlorine dioxide and ultraviolet radiation were carried out, taking city utility water and environment sight water as criterion. Looking into disinfection efficiency of fecas coliform and total coliform,continual disinfection power and by-product formation according to feces coliform and Total coliform. The better disinfection technology and run cost suiting different purpose is summed up.Conclusions are: when the contacting time is 30 minutes, controling number of fecas coliform under 10000MPN/L,2000MPN/L,1000MPN/L and 500 MPN/L chlorine dose are 1.2～1.8mg/L,2.0～2.5mg/L,2.0～3.0mg/L and 2.9～4.6mg/L, the run cost per ton water are 0.008/0.011yuan/t,0.010/0.014yuan/t,0.011/0.015yuan/t and 0.014/0.020yuan/t(without wiping off residual disinfector /wiping off residual disinfector); chlorine dioxide dose are 1.7～2.6 mg/L,2.6～4.0 mg/L,3.1～4.5 mg/L and 4.0～5.9mg/L, the run cost per ton water are 0.034/0.047yuan/t,0.049/0.069yuan/t,0.056/0.079yuan/t and 0.073/0.102yuan/t(without wiping off residual disinfector /wiping off residual disinfector); ultraviolet radiation dose are 25～40mJ/cm²,45～60mJ/cm²,65～100mJ/cm² and 75～120mJ/cm², the run cost per ton water are 0.018 yuan/t,0.025 yuan/t,0.036yuan/t and 0.054yuan/t.When the contacting time is 30 minutes, controling the number of Total coliform under 3MPN/L: chlorine dose and chlorine dioxide dose are 24.1～30.9mg/L and 11.5～13.3mg/L, the run cost per ton water are 0.105/0.147yuan/t and 0.179/0.250yuan/t ( without wiping off residual disinfector /wiping off residual disinfector); ultraviolet radiation is hardly meet the goal; 25～30mJ/cm² (Ultraviolet radiation dose)+4mgCl/L or 25～30mJ/cm²(Ultraviolet radiation dose)+3mgClO₂/L are needed, the run cost...