Treatment of Simulated Radioactive Cobalt Containing Wastewater by Ultra-low Pressure Reverse Osmosis Process
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摘要: 核电厂运行、维护和退役产生的放射性废水对社会环境和生命健康安全有严重危害。采用中试装置(144 L/h)研究了超低压反渗透(ULPRO)工艺对模拟放射性废水中目标核素钴(Co)的去除效果,确定了操作压力、回收率、进水浓度、共存离子及天然有机污染物对其影响规律。结果表明,Co去除率与操作压力正相关、与回收率负相关,随进水浓度增大而后恒定在99.5%,10 mg/L为其变化的临界浓度;共存离子仅Ca2+会抑制Co的去除,其他离子的促进作用强弱排序为Na+>Mg2+,SO42−>Cl−>NO3−;有机物污染造成膜通量下降9.4%,但Co去除率增大至99.97%。实验验证了ULPRO工艺处理模拟放射性含Co废水运行效果稳定、去除率高,可为工业应用提供指导。
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关键词:
- 低水平放射性废水 /
- 超低压反渗透(ULPRO) /
- 膜分离 /
- 钴(Co)
Abstract: The radioactive wastewater produced by the operation, maintenance and decommissioning of nuclear power plants is seriously harmful to the social environment and life and health safety. A pilot plant (144 L/h) is used to study the removal effect of cobalt (Co) from simulated radioactive wastewater by ultra-low pressure reverse osmosis (ULPRO) process. The effects of operating pressure, recovery rate, influent concentration, coexisting ions and natural organic pollutants on it are determined. The results show that the removal rate of Co is positively correlated with the operating pressure and negatively correlated with the recovery rate, the removal rate of Co is constant at 99.5% with the increase of influent concentration, and 10 mg/L is the critical concentration for its change; As for coexisting ions, only Ca2+will inhibit the removal of Co, and the promotion effect of other ions is in the order of Na+>Mg2+, SO42−>Cl−>NO3−; Organic pollution reduces the membrane flux by 9.4%, but the removal rate of Co increases to 99.97%. The experimental results show that the ULPRO process has stable operation effect and high removal rate for the treatment of simulated radioactive wastewater containing Co, which can provide guidance for industrial application. -
表 1 模拟放射性废水水质参数
Table 1. Water Quality Parameters of Simulated Radioactive Wastewater
参数 自来水 天然湖水 pH 8.05 8.85 电导率/(μS·cm−1) 276 1198 浊度/NTU 0.11 0.30① Na+浓度/(mg·L−1) 21.45 162.10 K+浓度/(mg·L−1) 2.12 12.51 Ca2+浓度/(mg·L−1) 20.48 108.35 Mg2+浓度/(mg·L−1) 11.04 47.14 Cl−浓度/(mg·L−1) 12.47 141.80 NO3−浓度/(mg·L−1) 4.23 13.78 SO42−浓度/(mg·L−1) 24.78 178.12 NPOC②/(mg·L−1) 1.40 16.6 注:①使用0.45 μm微滤膜过滤之后的湖水浊度;②NPOC—有机物浓度。 表 2 阳离子水合半径
Table 2. Cation Hydration Radius
离子种类 Co2+ Na+ Mg2+ Ca2+ 水合离子半径/nm 0.423 0.365 0.429 0.412 -
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