Liu Tongzhou, Wang Hong, Zhang Zhen, Zhao Da
Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055, PR China.
School of Environmental Science and Engineering, South University of Science and Technology of China, Shenzhen 518055, PR China; Engineering Innovation Center (Beijing), South University of Science and Technology of China, Beijing 100083, PR China.
Chemosphere. 2017 Aug;180:160-168. doi: 10.1016/j.chemosphere.2017.04.023. Epub 2017 Apr 6.
Contaminants released from river sediments are catching more attentions for river environmental management, especially when external sources of river pollution have been well controlled. To reduce the contaminant release from sediments, in-situ capping is often applied because of its effective reduction of contaminant flux and minimal disturbance to the surroundings. As an innovative sediment capping material, iron-oxide coated zeolite (IOCZ) was synthesized, characterized, and evaluated in this study. Its performance for the NH-N, PO-P, and S-S fixation in aqueous solutions was evaluated using batch and fixed-bed column experiments. IOCZ was found effective as a sorbent for NH-N, PO-P, and S-S with the maximum Langmuir sorption capacities of 6.23 mg N g, 0.966 mg P g, and 1.70 mg S g, respectively. Under the studied conditions, the whole breakthrough process in the fixed-bed column could be well described by Thomas model, indicating IOCZ can effectively retard NH-N, PO-P, and S-S under flowing conditions. In addition, desorption simulative experiments suggested that the retarded pollutants were stable even under some extreme environments such as flooding or tiding. Therefore, IOCZ seems a promising capping material to control the release of NH-N, HPO-P, and S-S from river sediments.
河流沉积物释放的污染物在河流环境管理中受到越来越多的关注，尤其是在河流污染的外部来源得到有效控制的情况下。为了减少沉积物中污染物的释放，原位覆盖技术因其能有效降低污染物通量且对周围环境干扰最小而经常被采用。在本研究中，合成、表征并评估了一种新型的沉积物覆盖材料——氧化铁包覆沸石（IOCZ）。通过批次实验和固定床柱实验评估了其对水溶液中NH-N、PO-P和S-S的固定性能。结果发现，IOCZ作为NH-N、PO-P和S-S的吸附剂效果良好，其最大朗缪尔吸附容量分别为6.23 mg N g、0.966 mg P g和1.70 mg S g。在所研究的条件下，固定床柱中的整个穿透过程可用托马斯模型很好地描述，这表明IOCZ在流动条件下能有效阻滞NH-N、PO-P和S-S。此外，解吸模拟实验表明，即使在洪水或潮汐等一些极端环境下，被阻滞的污染物也是稳定的。因此，IOCZ似乎是一种有前景的覆盖材料，可用于控制河流沉积物中NH-N、HPO-P和S-S的释放。
