水厂臭氧-生物活性炭工艺对短链PFCs及DOM去除特性的中试  

Pilot Test of O_(3)-BAC Process for Characteristics of Short-Chain PFCs and DOM Removal in WTP

作　　者：杨宁 许咏穗 侯英娜 黄国庆 费霞丽 邓慧萍[1] YANG Ning;XU Yongsui;HOU Yingna;HUANG Guoqing;FEI Xiali;DENG Huiping(College of Environmental Science and Engineering,Tongji University,Shanghai 200092,China;Xiamen Municipal Water Group Co.,Ltd.,Xiamen 361000,China)

机构地区：[1]同济大学环境科学与工程学院,上海200092 [2]厦门市政水务集团有限公司,福建厦门361000

出　　处：《净水技术》2024年第5期80-91,142,共13页Water Purification Technology

基　　金：上海市“科技创新行动计划”社会发展科技攻关项目(20DZ1204102)。

摘　　要：全氟化合物(PFCs)在水环境中广泛分布并存在潜在毒性,活性炭吸附是目前被认为从饮用水中去除PFCs的有效技术之一。然而,关于臭氧-生物活性炭(O3-BAC)在实际水体中对短链PFCs去除特性的研究较少,因此在目前地表水环境中短链PFCs的污染水平不断升高的背景下,亟需评估该工艺的应用效果。文中以水厂砂滤产水为水源,研究了3种短链PFCs(PFBA、PFPeA、PFHxA)和溶解性有机物(DOM)在连续运行90 d的O3-BAC中试装置中的去除效果,同时探讨了关停臭氧和臭氧的投加量对短链PFCs和DOM去除效果的影响。结果表明,随着运行时间的延长,3种短链PFCs在O3-BAC中试中的去除率显著下降并且出现了PFCs穿透和解吸附现象,去除率下降程度为:PFBA>PFPeA>PFHxA,而DOM相关的DOC、UV_(254)和Φ_((T,n))指标的去除率下降程度则相对缓慢。臭氧的投加能够氧化DOM从而改善短链PFCs在炭滤中的吸附去除,关停臭氧后流入炭滤的DOM会抢占已吸附短链PFCs的吸附位点,使PFCs解吸附提前发生。过高的臭氧投加量又会使更具竞争性的低分子量有机物增多,从而削弱炭滤对短链PFCs的去除能力。Perfluorinated compounds(PFCs)are widely distributed and potentially toxic in the aqueous environment,and activated carbon adsorption is currently considered one of the effective technologies for PFCs removal in drinking water.However,there are fewer studies on the removal characteristics of ozone-bioactivated carbon(O_(3)-BAC)for short-chain PFCs in real water bodies,and therefore there is an urgent need to assess the effectiveness of the application of this process in the context of the current increasing pollution levels of short-chain PFCs in surface water environments.In this study,the removal of three short-chain PFCs(PFBA,PFPeA,PFHxA)and dissolved organic matter(DOM)was investigated in an O_(3)-BAC pilot plant that was operated continuously for 90 days using sand filtration effluent from a water treatment plant as the water source,and the effects of ozone shutdown and ozone dosage on the removal of short-chain PFCs and DOM were also investigated.The results showed that the removal rates of the three short-chain PFCs in the O_(3)-BAC pilot plant decreased significantly with the increase of operation time and the phenomenon of penetration and desorption of PFCs appeared,and the degree of the removal rates decreased as follows:PFBA>PFPeA>PFHxA,while the removal rates of DOC,UV_(254)andΦ_((T,n))indices related to DOM decreased relatively slowly.Ozone dosing could oxidize DOM to improve the adsorption and removal of short-chain PFCs in the charcoal filter,and DOM flowing into the charcoal filter after the ozone was turned off would seize the adsorption sites of adsorbed short-chain PFCs,causing the desorption of PFCs to occur prematurely.Excessive ozone dosage could in turn increase the more competitive low molecular weight organics,thus weakening the removal capacity of carbon filtration for short-chain PFCs.

关 键 词：臭氧-生物活性炭 全氟化合物 溶解性有机物 中试 三维荧光光谱 

分 类 号：TU991[建筑科学—市政工程]