A2O小试系统与实际工艺单元中OPEs去除的比较

Elimination of organophosphate esters in A2O process of WWTP and pilot plant

污水处理厂出水是环境中OPEs的重要来源,且污水处理厂的生物处理单元可去除部分OPEs.为了更好的研究污水处理厂工况条件,以达到优化去除宏量有机物和微量有机物的目的,良好的小试装置必不可少.本研究在实验室设计并安装了一套A2O小试装置,根据有机磷酸酯的结构特点,在进水中投加了3种代表性的有机磷酸酯.比较了小试装置中与实际工艺单元中这3种有机磷酸酯的去除规律,发现OPEs在A2O小试中的去除规律与实际工艺单元中相似,磷酸三丁氧酯(TBEP)在两种工况下去除效果均较好,总去除率分别为84.6%与83.6%,磷酸三(1-氯-2-丙基)酯(TCPP)去除效果均较差.在不同处理单元中,由于厌氧池中主要发生水解作用,TCPP在两种工况下的厌氧池中都可去除,且在A2O小试厌氧池中的去除率(57.7%)优于实际工艺(25.5%).TBEP的去除主要发生在好氧池中,且A2O小试二沉池可以有效去除TBEP(67.9%),优于实际工艺的二沉池.两种工况下,好氧池曝气强度较大,引入磷酸三(1-氯-2-丙基)酯(TCPP)不易降解,TCPP在好氧池去除效果较差.除此之外,优化了小试装置的OPEs的检测取样量保证检测的准确性.

Many studies have shown that one of the important sources of OPEs in the environment is effluent of wastewater treatment plant(WWTP)and the biological treatment units in WWTP can remove some OPEs.In order to optimize the operating conditions of WWTP to make a better removal of macro and micro organic compounds,a suitable laboratory device is necessary.A set of A2O device was designed and installed in the laboratory and 3kinds of representative OPEs were added into the influent.The results show that the removal efficiencies of OPEs in the units of laboratory device were similar tothat in the same units of WWTP.The removal efficiencies of TBEP under both process conditions werehigh,with total removal rate of 84.6%and 83.6%respectively,while the removal efficiencies of TCPP under both conditions were low.In different treatment units,both TCPP in the anaerobic tank under two process conditions could be remove due to the hydrolysis in the anaerobic tank,and the removal rate in the anaerobic tank of laboratory A2O device(57.7%)was higher than that in the WWTP(25.5%).The removal of TBEP mainly occurred in the aerobic tank,and TBEP removal efficiency(67.9%)in secondary sedimentation tank of laboratory A2O device was higher than that in WWTP.Under twoprocess conditions,the aeration intensity of aerobic tank was large and the added tris(1-chloro-2-propyl)phosphate(TCPP)was hard to degrade,leading to the poor removal of TCPP in the aerobic tank.In addition,the sampling quantity of OPEs in A2O device was optimized to ensure the accuracy of the test.