| With the rapid development of human society, agricultural, municipal and industrial waste lot of emissions, result in a large area of eutrophic water. The water includes rich nutrients to promote the growth of blue-green algae, actinomycetes. Geosmin (GSM), 2-methylisoborneol (2-MIB) they produce, are a common causing taste and odor problems in drinking water. They are not only from the sensory aspect seriously reducing the quality of drinking water, but also low odor threshold, and specially constructed of tertiary alcohols. So conventional process is difficult to deal with them to the human olfactory threshold value (10 ng/L the limit of GB5749-2006). In order to solve the drawbacks of conventional treatment process, to meet user requirements on water quality, following the normal process to add depth processing technology has become a necessary choice. In this study, with reference to existing based on the study, comprehensive comparison of various advanced oxidation removal of GSM and 2-MIB performance, choose of UV/H2O2 advanced oxidation technology as the depth of the treatment process. In the process, independently design select purchase and assemble the laboratory equipment. And carry out a small pilot study and test pilot.The main research contents include three aspects:(1) through the small pilot test study the effective degradation of GSM,2-MIB by UV/H2O2; (2) through the small pilot test study the reaction kinetics of degradation of GSM and 2-MIB by UV/H2O2; (3) through pilot trials, optimization of operating parameters of GSM and 2-MIB.The results show that, in the laboratory trials, the removal efficiency of 2-MIB increased with the concentration of H2O2 increasing; 764 ng/L of 2-MIB was reduced to the detection limit (<5 ng/L) after 8 min reaction with 3.92 mg/L of H2O2; 702 ng/L of 2-MIB was reduced to 42 ng/L after 8 min reaction with 1.93 mg/L of H2O2. The results show that, in the laboratory trials,582ng/L of GSM was reduced to 24 ng/L and 8 ng/L after 8 min and 10 min reaction, respectively. The removal efficiency of GSM and 2-MIB by is significant by UV/H2O2, the removal rate with increasing H2O2 concentration increasing; the process of degradation of both substances followed first kinetic model, and the value of reaction rate constants K increased with increasing H2O2 concentration. Under the same conditions of the other reaction parameters, when the H2O2 concentration from 1.93 mg/L increased 3.92 mg/L the GSM kinetic constant K value added from 0.5064 to 0.6809. Under the same conditions of the other reaction parameters, when the H2O2 concentration from 1.93 mg/L increased 3.92 mg/L the 2-MIB kinetic constant K value added from 0.3719 to 0.6975.Introduced experimental design Design-Expert software into the pilot test and planed the process of pilot test. Did regression analysis to get parametric equation, among the factors draw a response surface plot, and then optimized parameters of test conditions. Optimization of parameters for 2-MIB was H2O2 dosage of 6 mg/L, the dose power 0.30 kW·h/m3,2-MIB dosage of 275 ng/L, and at this time 2-MIB removal rate was 96.58%, the remaining was 9.41 ng/L. Optimization of parameters for GSM was H2O2 dosage of 7.5 mg/L, the dose power 0.356 kW·h/m3, GSM dosage of 300 ng/L, and at this time the degradation rate of GSM 97.14%, and the remaining was 8.58 ng/L. Carry out the reaction in the appropriate conditions, the two odor compounds all could be reduced to 10 ng/L or less. Detect reaction effluent water quality indicators that demonstrated better than "drinking water health standards" (GB5749-2006) related limits. |
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