Department of Civil Engineering, The University of Akron, OH 44325-3905, USA.
Department of Civil Engineering, The University of Akron, OH 44325-3905, USA.
J Environ Sci (China). 2023 Jun;128:161-170. doi: 10.1016/j.jes.2022.08.015. Epub 2022 Aug 18.
Cyanobacteria can produce cyanotoxins such as microcystin-LR (MC), saxitoxin (STX), and anatoxin-a (ANTX-a) which are harmful to humans and other animals. Individual removal efficiencies of STX and ANTX-a by powdered activated carbon (PAC) was investigated, as well as when MC-LR and cyanobacteria were present. Experiments were conducted with distilled water and then source water, using the PAC dosages, rapid mix/flocculation mixing intensities and contact times of two drinking water treatment plants in northeast Ohio. At pH 8 and 9, STX removal was 47%-81% in distilled water and 46%-79% in source water, whereas it was 0-28% for pH 6 in distilled water and 31%-52% in source water. When 1.6 µg/L or 20 µg/L MC-LR was present with STX, STX removal was increased with PAC simultaneously removing 45%-65% of the 1.6 µg/L MC-LR and 25%-95% of the 20 µg/L MC-LR depending on the pH. ANTX-a removal at pH 6 was 29%-37% for distilled water and 80% for source water, whereas it was 10%-26% for pH 8 in distilled water and 28% for pH 9 in source water. The presence of cyanobacteria cells decreased ANTX-a removal by at least 18%. When 20 µg/L MC-LR was present with ANTX-a in source water, 59%-73% ANTX-a and 48%-77% of MC-LR was removed at pH 9 depending on the PAC dose. In general, a higher PAC dose led to higher cyanotoxin removals. This study also documented that multiple cyanotoxins can be effectively removed by PAC for water at pH's between 6 and 9.
蓝藻可以产生微囊藻毒素-LR（MC）、石房蛤毒素（STX）和anatoxin-a（ANTX-a）等毒素，这些毒素对人类和其他动物有害。研究了粉末活性炭（PAC）对 STX 和 ANTX-a 的单独去除效率，以及 MC-LR 和蓝藻存在时的去除效率。实验分别在蒸馏水和源水中进行，使用了俄亥俄州东北部的两个饮用水处理厂的 PAC 剂量、快速混合/絮凝混合强度和接触时间。在 pH 值为 8 和 9 时，STX 在蒸馏水中的去除率为 47%-81%，在源水中的去除率为 46%-79%，而在 pH 值为 6 时，蒸馏水中的去除率为 0-28%，源水中的去除率为 31%-52%。当 1.6 µg/L 或 20 µg/L MC-LR 与 STX 共存时，随着 PAC 的同时去除，STX 的去除率会增加，同时去除 45%-65%的 1.6 µg/L MC-LR 和 25%-95%的 20 µg/L MC-LR，具体取决于 pH 值。在 pH 值为 6 时，ANTX-a 在蒸馏水中的去除率为 29%-37%，在源水中的去除率为 80%，而在 pH 值为 8 时，蒸馏水中的去除率为 10%-26%，在 pH 值为 9 时，源水中的去除率为 28%。蓝藻细胞的存在至少使 ANTX-a 的去除率降低了 18%。当 20 µg/L MC-LR 与源水中的 ANTX-a 共存时，在 pH 值为 9 时，取决于 PAC 剂量，ANTX-a 的去除率为 59%-73%，MC-LR 的去除率为 48%-77%。一般来说，较高的 PAC 剂量会导致更高的蓝藻毒素去除率。本研究还证明，在 pH 值为 6 至 9 之间的水中，PAC 可以有效去除多种蓝藻毒素。
