Aarhus Water Ltd., Bautavej 1, DK-8210 Aarhus V, Denmark E-mail:
Water Sci Technol. 2013;68(8):1852-6. doi: 10.2166/wst.2013.436.
This is an investigation of chemical disinfection, with peracetic acid (PAA), in a tertiary sand filter at a full scale activated sludge plant with nitrification/denitrification and P-removal. The reduction efficiency of Escherichia coli and intestinal enterococci in the sand filter is reported. E. coli log reductions of between 0.4 and 2.2 were found with contact times from 6 to 37 min and with dosing from 0 to 4.8 mg L(-1). The average log reduction was 1.3. The decomposition products, bromophenols, chlorophenols and formaldehyde and residual H2O2 were measured before and after the sand filter. The residual H2O2 concentration in the effluent was critical at short contact times and high dosages of PAA due to the discharge limit of 25 μg L(-1). The other three products could not be detected at 0.1 μg L(-1) levels. The chemical cost of PAA dosing is estimated to be 0.039 US$ m(-3) treated wastewater.
这是一项关于化学消毒的研究，采用过氧乙酸（PAA）对硝化/反硝化和磷去除三级砂滤池进行消毒。报告了砂滤器中大肠杆菌和肠道肠球菌的减少效率。接触时间为 6 至 37 分钟，投加量为 0 至 4.8 毫克/升时，发现大肠杆菌的对数减少率在 0.4 至 2.2 之间。平均对数减少率为 1.3。在砂滤器前后测量了分解产物溴酚、氯酚和甲醛以及残留的 H2O2。由于 25μg/L 的排放限值，在短接触时间和高 PAA 剂量下，出水的残留 H2O2 浓度至关重要。其他三种产物在 0.1μg/L 水平下无法检测到。过氧乙酸投加的化学成本估计为 0.039 美元/立方米处理后的废水。
