Modified zeolite-coupled activated carbon enhanced coagulation treatment of micro-pollution source water
Yaqian MA1, Yanli KONG 1*, Lei DING 1*, Zhonglin CHEN 2, Jimin SHEN2
1. School of Civil Engineering and Architecture, Anhui University of Technology, Ma'anshan, Anhui 243032, China
2. State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang 150090, China
Abstract：In recent years, the water quality of drinking water sources in China is facing very serious situation, especially for micro-polluted water, and the existing water plant conventional treatment process cannot effectively ensure the removal of pollutants from the water plant, so it is necessary to use enhanced coagulation treatment technology, economically to improve the water quality, and to ensure the safety of drinking water is particularly important. The combination modified zeolite powder (MZ) coupling powder activated carbon (PAC) to enhance coagulation removing micro-pollution sources of ammonia nitrogen (NH3-N), oxygen consumption (CODMn), UV254 and turbidity were studied using static adsorption and six-link mixer beaker experiments. Experimental water was taken from micro-polluted water sources in a city of south China, and the water quality was more seriously polluted with higher concentrations of soluble organic matter. The results showed that MZ increased the surface area and average adsorption aperture, the surface of MZ was rougher while the crystal structure of the MZ had not changed and the removal ability of NH3-N enhanced. MZ-PAC adsorption had the synergetic action for NH3-N removing, there was slightly antagonism for CODMn removal. MZ-coupled PAC to enhance coagulation significantly improved the removal of NH3-N, CODMn, UV254, and turbidity, with the treated water NH3-N<0.5 mg/L, CODMn<3.0 mg/L and turbidity<1 NTU. The different cast-plus methods of MZ and PAC influenced the enhanced coagulation treatment effect, and the best way to add PAC and MZ was in the early stages of flocculation, which avoided the flocs of MZ packages, strengthened the PAC on organic matter removal, and further improved the removal of NH3-N by MZ. Otherwise, the turbidity of the water increased, especially in the late stage of flocculation. Coupling enhancing coagulation results in lower the absolute value of Zeta potential and repulsion between colloid. Floc size increasing and sticky phenomenon made the resistant ability stronger.