预臭氧对常规工艺去除2-MIB&GSM效果与机理中试研究

Pilot Study on the Efficiency and Mechanism of Pre-ozonation Conventional Process for 2-MIB&GSM Removal

通过某水厂中试基地,研究了预臭氧与臭氧预氧化后常规工艺对嗅味物质2-甲基异茨醇(2-MIB)、土腥素(GSM)的去除效果及机理,分析了以TOC、UV_(254)为表征的有机物变化与作用。研究数据显示,未采用臭氧预氧化时,常规工艺对2-MIB和GSM的累积去除率为29.8%和31.3%。参照水厂实际预臭氧投加浓度,当预臭氧投加量为0.56 mg/L时,预臭氧段对2-MIB和GSM的去除率为34.60%和35.84%,略有上升;对UV_(254)和TOC的去除效果较低,去除率分别为6.5%和3.4%,但是分子量分布测试数据显示,预臭氧段出水中大分子有机物分布明显增加,在该浓度条件下,预臭氧对有机物产生了良好的微絮凝作用。经臭氧预氧化后,常规工艺(砂滤出水)对2-MIB和GSM累积去除率可达到58.05%和60.83%,显著上升。结果表明,预臭氧对常规工艺去除2-MIB和GSM具有明显提高的效果,不仅是因其具有较强的氧化能力,其次还有显著的微絮凝促进作用,增强了常规工艺的混凝、沉淀和过滤对2-MIB、GSM去除。

The removal efficiency and mechanism of 2-methylisoborneol （MIB） and geosmin （GSM） by conventional process after pre-ozonation and ozone pre-oxidation were researched through a pilot test base in a waterworks. The changes and functions of organics were analyzed which was characterized by TOC and UV254. The results showed that the removal rate of 2-M/B and GSM by convention-treatment process were 29.8% and 31.3% respectively without ozone pre-oxidation. Based on the actual dosing ofpre-ozone in waterworks, when the dosage was 0.56 mg/L, the removal rate of 2-M1B and GSM were 34.60% and 35.84% respectively in pre-ozonation stage, which showed a slightly growth. However, the removal rate of UV254 and TOC were 6.5% and 3;4% respectively which were lower. But the molecular weight distribution measurement test data showed that the macro molecular distribution had a significantly increase in pre-oxidation process. Under this concentration, pre-ozonation had a good function ofmicro-flocculation for organics. And the accumulated removal rate of 2-MIB and GSM by conventional process after ozonation were 58.05% and 60.83% respectively, which showed a apparently growth. The research showed that, the removal efficiency of 2-MIB and GSM had a significant improvement by conventional process after pre-ozonation. It was not only because of its strong oxidation ability, but also had a significant promoting effect for micro-flocculation,enhanced the coagulation, sediment and filtration for 2-MIB and GSM removal.