Research On Mobile Emergency Drinking Water Treatment Technology

With the rapid development of China’s urbanization, water security is facing more and more serious threat. Simultaneously. Sudden water pollution incidents influencing drinking water safety have occurred occasionally in recent years, and the occurrence of frequency and the degree of harm exhibit a rising trend by year, therefore drinking water safety of the residents in affected area is difficult to guarantee.It is necessary to develop advanced emergency drinking water supply equipment, for human communities accessing to clean drinking water and adequate sanitation,however, the existing emergency water supply equipment is more technology-based membrane treatment, which pretreatment, start-up, operation and maintenance requirements are stricter, and the operating cost is high. Therefore, to solve the large variation of water quality in emergency, it is urgent to develop of the integrated water supply equipment with strong adaptability, simple operation, fast start, stable operation and easy to move.In this study, a composite coagulants with pre-oxidation, flocculation, coagulation and disinfection was designed. Pre-oxidant and coagulant aid reduced the dosing amount of coagulant effectively, and enhanced coagulation effect. The results of Coagulation experiment showed that:When the raw water turbidity within the range of 8.33～626 NTU, the composite ratio of PAC-PAM were composited to PAC/PAM 150:1～180:1, treated water turbidity could be dropped to 0.74-1.60 NTU. When raw water CODMn was in range of 2.9-5.3 mg/L, with the optimum composite ratio of KHSOs and PAC in 1:25-1:30, CODMn of effluent was 0.038～0.438 mg/LThis study assembled an innovative mobile emergency drinking water equipment, which integrated line strainer, pre-oxidation/coagulation, primary filter, composite adsorption, precision filter and disinfection into a semi-trailer truck equipped with diesel generators. This equipment could provide collected pretreatment, conventional treatment, and deep treatment for disaster rescue under various terrain conditions.In the on-site reservoir water treatment experiments,when raw water temperature, PH value, turbidity, CODMn, and NH4+-N were 4～6℃,7.2～8.3, 0.80～2.32 NTU,2.48～3.25 mg/L,0.032～0.086 mg/L, respectively. The average removal rates of turbidity, CODmn, and NH4+-N were 68.8%,20.1% and 56.9%, respectively with PAC dosage of 25 mg/L, PAM dosage of 0.2 mg/L, KHSOs dosage of 0.5 mg/L, effluent index satisfied all requirements for safe water.In the ground water treatment experiment, when raw water temperature, PH value, turbidity, CODMn, NH4+-N, NO2--N, NO3--N, UV254 and UV410 were 33-37℃, 7.5～8.5,89～102.1 NTU,1.900～6.081 mg/L,0.073-0.850 mg/L,0.020～0.036 mg/L, 1.255～3.496 mg/L,0.032～0.053 mg/L and 0.026～0.055 mg/L,respectively. The result showed that the raw water qulality could be improved with adding acomposite chemicals, which contained PAC 0.1 mg/L, PAM dosage of 0.1 mg/L, KHSOs dosage of 0.7 mg/L, the average removal rate of those indxe were 99.5%,50.6%, 25.8%,1.6%,32.6% and 86.9%, respectively. The effluent satisfied the "China Standards for Drinking Water Quality" (GB 5749-2006).