药物对A/A/O系统中NDMA及其总前体物去除的影响

在厌氧/缺氧/好氧(A/A/O)脱氮除磷系统中分别投加氯苯那敏和雷尼替丁,研究了这两种含有二甲胺基团的药物对A/A/O系统中N-亚硝基二甲胺(NDMA)及其总前体物去除效果的影响.结果表明, A/A/O系统对氯苯那敏和雷尼替丁的去除率较低,分别为32%和58%,且主要通过厌氧过程去除.外加氯苯那敏会导致系统对总氮的去除率从58%降至24%,同时引起出水氨氮浓度上升.雷尼替丁的投加会明显抑制系统对NDMA的去除,其去除率从90%降至66%.A/A/O反应器中NDMA的去除并不完全受生物脱氮过程的影响.由于具有较高的NDMA生成潜能,外加氯苯那敏,雷尼替丁会引起进水中NDMA总前体物浓度大幅增加,且导致A/A/O系统对NDMA总前体物的去除率明显下降 (从70%降到31%~33%).

Effects of pharmaceuticals on the removal of NDMA and NDMA total precursors in an anaerobic/ anoxic/ oxic system

Chlorpheniramine and ranitidine were added to an anaerobic/anoxic/oxic (A/A/O) nutrient removal system, and the influences of these two pharmaceuticals with dimethylamine group on the removal of N-nitrosodimethylamine (NDMA) and NDMA total precursors were investigated. The results show that the removals of chlorpheniramine and ranitidine in the A/A/O system were low (32% and 58%, respectively), and they were mainly removed by anaerobic processes. Total nitrogen removal efficiency decreased from 58% to 24% due to chlorpheniramine addition, and concentration of ammonia in the effluent increased obviously. Ranitidine addition caused obvious inhibition of NDMA removal, resulting in its decrease from 90% to 66%. However, the removal of NDMA had no necessary correlation with the removal of total nitrogen in A/A/O system. Due to their high NDMA formation potentials, addition of chlorpheniramine and ranitidine resulted in a significant increase in the concentration of NDMA total precursors; correspondingly, removal efficiencies of NDMA total precursor declined obviously (from 70% to 31%~33%).