Savannah River Ecology Laboratory, University of Georgia, PO Drawer E, Aiken, SC 29802, USA.
J Environ Manage. 2018 Jul 15;218:245-255. doi: 10.1016/j.jenvman.2018.04.014. Epub 2018 Apr 20.
The H-02 wetland was constructed to treat building process water and storm runoff water from the Tritium Processing Facility on the Department of Energy's Savannah River Site (Aiken, SC). Monthly monitoring of copper (Cu) and zinc (Zn) concentrations and water quality parameters in surface waters continued from 2014 to 2016. Metal speciation was modeled at each sampling occasion. Total Cu and Zn concentrations released to the effluent stream were below the NPDES limit, and the average removal efficiency was 65.9% for Cu and 71.1% for Zn. The metal-removal processes were found out to be seasonally regulated by sulfur cycling indicated by laboratory and model results. High temperature, adequate labile organic matter, and anaerobic conditions during the warm months (February to August) favored sulfate reduction that produced sulfide minerals to significantly remove metals. However, the dominant reaction in sulfur cycling shifted to sulfide oxidation during the cool months (September to next March). High concentrations of metal-organic complexes were observed, especially colloidal complexes of metal and fulvic acid (FA), demonstrating adsorption to organic matter became the primary process for metal removal. Meanwhile, the accumulation of metal-FA complexes in the wetland system will cause negative effects to the surrounding environment as they are biologically reactive, highly bioavailable, and can be easily taken up and transferred to ecosystems by trophic exchange.
H-02 湿地的建造目的是处理美国能源部萨凡纳河场址（南卡罗来纳州艾肯）氚处理设施的建筑工艺用水和暴雨水。2014 年至 2016 年期间，继续对地表水中的铜 (Cu) 和锌 (Zn) 浓度和水质参数进行每月监测。在每次采样时对金属形态进行建模。释放到废水流中的总 Cu 和 Zn 浓度低于 NPDES 限值，Cu 的平均去除效率为 65.9%，Zn 的平均去除效率为 71.1%。实验室和模型结果表明，金属去除过程受硫循环季节性调节。高温、充足的可利用有机物质和温暖月份（二月至八月）的厌氧条件有利于硫酸盐还原，产生硫化物矿物，从而显著去除金属。然而，在凉爽月份（九月至次年三月），硫循环中的主要反应转变为硫化物氧化。观察到高浓度的金属有机络合物，尤其是金属和腐殖酸 (FA) 的胶体络合物，表明吸附到有机物上成为金属去除的主要过程。同时，金属-FA 络合物在湿地系统中的积累将对周围环境产生负面影响，因为它们具有生物反应性、高生物可利用性，并且可以通过营养交换很容易被吸收并转移到生态系统中。
