• 关键词：再生水  混凝  生物稳定性  可同化有机碳

• 基金项目：国家自然科学基金重点项目(No.51138006)

• 林文琪
• 1. 中国矿业大学(北京)化学与环境工程学院, 北京 100083;2. 清华大学环境学院 环境模拟与污染控制国家重点联合实验室, 北京 100084

• 于童
• 清华大学环境学院 环境模拟与污染控制国家重点联合实验室, 北京 100084

• 李国强
• 清华大学环境学院 环境模拟与污染控制国家重点联合实验室, 北京 100084

• 史晓洁
• 清华大学环境学院 环境模拟与污染控制国家重点联合实验室, 北京 100084

• 于彩虹
• 中国矿业大学(北京)化学与环境工程学院, 北京 100083

• 胡洪营
• 清华大学环境学院 环境模拟与污染控制国家重点联合实验室, 北京 100084

• 摘要：再生水在储存、输配过程中微生物的再生长现象给再生水的利用造成不利影响,因此,研究再生水的生物稳定性十分必要.本研究以可同化有机碳(AOC)表征再生水生物稳定性,考察了混凝处理对北京市再生水厂二级出水生物稳定性的影响.研究发现,二级出水中投加聚合氯化铝(PACl)剂量为20~120 mg·L^-1混凝处理后,水中溶解性有机碳(DOC)和不饱和有机物、含氮有机物(用UV₂₅₄表征)的去除率分别为3%~30%和10%~36%,水样中荧光物质的去除效果不明显.分子量为3000~20000 Da的有机物容易被混凝过程去除,但分子量小于3000 Da的有机物在混凝过程中几乎不能被去除.二级出水经混凝处理后,AOC水平有升高的趋势.在PACl投加量为60 mg·L^-1时,混凝前后二级出水的AOC水平分别为48~485μg·L^-1和121~910μg·L^-1,变化率为-4%~124%,说明混凝处理导致了水样水质生物稳定性降低.

• Abstract：It is essential to investigate the biological stability of the reclaimed water, since the microbial regrowth will prohibit the application of the reclaimed water during its storing and distributing. The study herein applied assimilable organic carbon (AOC) to evaluate the effect of coagulation treatment on the biological stability of the secondary effluents, deriving from different water reclamation plants in Beijing. It is found that the removal efficiencies of dissolve organic carbon (DOC) and UV absorbance at 254 nm (UV₂₅₄) were 3%~30% and 10%~36%, respectively, while processing the secondary effluents by poly-aluminum chloride (PACl) ranged from 20 to 120 mg·L^-1, however, the fluorescent substances was hard to remove by coagulation. The results of molecular weight distribution show that coagulation could remove the organic matters with the molecular weight between 3000~20000 Da effectively, but the organic matters with the molecular weight less than 3000 Da was rarely eliminated. The AOC level increased at the PACl dosage of 60 mg·L^-1, the AOC level of secondary effluents were 48 to 485 μg·L^-1 and 121 to 910 μg·L^-1 before and after coagulation, the increase ratio varied from -4% to 124%, indicating that the reclaimed water quality was deteriorated after coagulation.

• Key words：reclaimed water  coagulation  biological stability  assimilable organic carbon (AOC)

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