Politecnico di Milano, DICA - Environmental Section, Piazza Leonardo da Vinci 32, 20133 Milano, Italy E-mail:
Università degli Studi di Milano Bicocca, DISAT, Piazza della Scienza 1, 20126 Milano, Italy.
Water Sci Technol. 2013;68(12):2638-44. doi: 10.2166/wst.2013.542.
The paper is a review of previous research on secondary effluent disinfection by peracetic acid (PAA) integrated with new data about the effect of a preliminary flash-mixing step. The process was studied at bench and pilot scale to assess its performance for discharge in surface water and agricultural reuse (target microorganisms: Escherichia coli and faecal coliform bacteria). The purposes of the research were: (1) determining PAA decay and disinfection kinetics as a function of operating parameters, (2) evaluating PAA suitability as a disinfectant, (3) assessing long-term disinfection efficiency, (4) investigating disinfected effluent biological toxicity on some aquatic indicator organisms (Vibrio fischeri, Daphnia magna and Selenastrum capricornutum), (5) comparing PAA with conventional disinfectants (sodium hypochlorite, UV irradiation). PAA disinfection was capable of complying with Italian regulations on reuse (10 CFU/100 mL for E. coli) and was competitive with benchmarks. No regrowth phenomena were observed, as long as needed for agricultural reuse (29 h after disinfection), even at negligible concentrations of residual disinfectant. The toxic effect of PAA on the aquatic environment was due to the residual disinfectant in the water, rather than to chemical modification of the effluent.
本文是对过氧乙酸（PAA）对二级出水进行消毒的先前研究的综述，并结合了关于初步闪式混合步骤效果的新数据。该工艺在实验室和中试规模进行了研究，以评估其用于地表水排放和农业回用的性能（目标微生物：大肠杆菌和粪大肠菌群）。研究目的是：（1）确定 PAA 衰减和消毒动力学作为操作参数的函数，（2）评估 PAA 作为消毒剂的适用性，（3）评估长期消毒效率，（4）研究消毒后出水对一些水生指示生物（发光菌、大型蚤和盐单胞藻）的生物毒性，（5）比较 PAA 与传统消毒剂（次氯酸钠、紫外线照射）。PAA 消毒能够符合意大利关于回用的规定（大肠杆菌 10 CFU/100 毫升），并且具有竞争力。只要需要用于农业回用（消毒后 29 小时），即使在残留消毒剂浓度可忽略不计的情况下，也不会观察到再生现象。PAA 对水生环境的毒性作用是由于水中残留的消毒剂，而不是由于出水的化学修饰。
