Study On The Secondary Effluent Of Urban Wastewater Treatment Plant Reuse For Boiler Feed Water By Reverse Osmosis Technology

Reverse Osmosis technology used for treating the secondary effluent of Urban Wastewater Treatment Plant reuse for Boiler Feed Water were studied in this paper. Studied the treatment effect and effecting factors of pretreatment system(with Flocculation Filtration+Active Carbon Filtration/Adsorption+ Precise Filter) and Reverse Osmosis system by experiment, determine the optimal working condition and optimal operation parameters of the system in different water conditions.Choice PAC + PAM as a flocculants, dosing PAC:30mg/L,PAM:0.6mg/L in medium temperature (18~20℃)conditions. Dosing PAC:50mg/L,PAM:1.0mg/L in low temperature(8~10℃) conditions. Removal rate of turbid degree of treated effluent: 94.8%~96.1%;CODGr:48.5%~54.1%;suspended substance:65.7~67.0%.The period of backwashing cycle was determined for 16h, the upward reverse rinse intensity is q=16.94 L/(s·m~2), continual upward reverse for 15 min, then the filtration capacity of filter material was recovered.Determined the activated carbon that produced from Beijing were the most appropriate by static adsorption experiment, when the filtration velocity was 0.4m/h,colority of effluent of active carbon filtration/adsorption reactor was 1.0(Multiple); suspended substance of effluent was 1.4mg/L~1.7mg/L.the period of rinse cycle of active carbon filtration/adsorption reactor was 32h.The upward reverse rinse intensity was q=8.4 L/(s·m~2), continual upward reverse for 20 min, then the filtration capacity of active carbon filtration/adsorption reactor was recovered. The regeneration cycle of active carbon was 60 d.The operating parameters of 1 # membrane module was: pressure of influent between1.1~1.39MPa; pressure of concentrated water between 1.0~1.26MPa; recovery between 12%~17.2%。The operating parameters of 2 # membrane module was: pressure of influent between 0.9~1.2MPa; pressure of concentrated water between 0.7~1.1MPa; recovery between 10%~16%.Conductivity of effluent﹤6.0μS /cm,desalination rate of reverse osmosis system was 99.3%。The advantages of the process: stable treatment effect, low running costs, Wide range of applications and so on. It has high application value.