School of Civil, Environmental and Chemical Engineering, RMIT University, Melbourne, Victoria 3001, Australia.
Water Res. 2012 Jun 15;46(10):3229-39. doi: 10.1016/j.watres.2012.03.024. Epub 2012 Apr 2.
While reverse osmosis (RO) technology is playing an increasingly important role in the reclamation of municipal wastewater, safe disposal of the resulting RO concentrate (ROC), which can have high levels of effluent organic pollutants, remains a challenge to the water industry. The potential of UVC/H(2)O(2) treatment for degrading the organic pollutants and increasing their biodegradability has been demonstrated in several studies, and in this work the impact of the water quality variables pH, salinity and initial organic concentration on the UVC/H(2)O(2) (3 mM) treatment of a municipal ROC was investigated. The reduction in chemical oxygen demand and dissolved organic carbon was markedly faster and greater under acidic conditions, and the treatment performance was apparently not affected by salinity as increasing the ROC salinity 4-fold had only minimal impact on organics reduction. The biodegradability of the ROC (as indicated by biodegradable dissolved organic carbon (BDOC) level) was at least doubled after 2 h UVC/H(2)O(2) treatment under various reaction conditions. However, the production of biodegradable intermediates was limited after 30 min treatment, which was associated with the depletion of the conjugated compounds. Overall, more than 80% of the DOC was removed after 2 h UVC/3 mM H(2)O(2) treatment followed by biological treatment (BDOC test) for the ROC at pH 4-8.5 and electrical conductivity up to 11.16 mS/cm. However, shorter UV irradiation time gave markedly higher energy efficiency (e.g., EE/O 50 kWh/m(3) at 30 min (63% DOC removal) cf. 112 kWh/m(3) at 2 h). No toxicity was detected for the treated ROC using Microtox(®) tests. Although the trihalomethane formation potential increased after the UVC/H(2)O(2) treatment, it was reduced to below that of the raw ROC after the biological treatment.
虽然反渗透 (RO) 技术在城市污水再生中发挥着越来越重要的作用，但安全处理产生的反渗透浓缩物 (ROC) 仍然是水行业面临的挑战。已有多项研究表明，UVC/H2O2 处理可有效降解有机污染物并提高其可生物降解性，本研究考察了 pH 值、盐度和初始有机浓度等水质变量对城市 ROC 中 UVC/H2O2（3mM）处理的影响。在酸性条件下，化学需氧量和溶解有机碳的去除速度和去除率明显更快更高，而盐度对处理性能没有明显影响，将 ROC 盐度增加 4 倍仅对有机物的去除有最小的影响。在各种反应条件下，经过 2 小时 UVC/H2O2 处理后，ROC 的可生物降解性（以可生物降解溶解有机碳 (BDOC) 水平表示）至少提高了一倍。然而，在 30 分钟处理后，可生物降解的中间产物的生成受到限制，这与共轭化合物的耗尽有关。在 pH 值为 4-8.5 和电导率高达 11.16 mS/cm 的条件下，经过 2 小时 UVC/3mM H2O2 处理和后续生物处理（BDOC 测试）后，超过 80%的 DOC 可被去除。然而，较短的紫外线照射时间可显著提高能源效率（例如，在 30 分钟（63%DOC 去除）时的 EE/O 为 50 kWh/m3，而在 2 小时时为 112 kWh/m3）。使用 Microtox®测试对处理后的 ROC 未检测到毒性。尽管 UVC/H2O2 处理后三卤甲烷生成潜能增加，但经过生物处理后，其生成潜能降低至低于原始 ROC。
