Optimized nano-scale zero-valent iron supported on treated activated carbon for enhanced nitrate and phosphate removal from water
Optimized nano-scale zero-valent iron supported on treated activated carbon for enhanced nitrate and phosphate removal from water
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DOI：
10.1016/j.cej.2016.10.080
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发表时间：
2017-02-01
影响因子：
15.1
通讯作者：
Matsunaga, Nobuhiro
中科院分区：
文献类型：
--
作者：
Khalil, Ahmed M. E.;Eljamal, Osama;Matsunaga, Nobuhiro
负载型纳米级零价铁（nZVI）是一种适用于地下水和废水处理的材料。它可以防止纳米颗粒团聚，提高其水力导电性。然而，这些支撑的nZVI颗粒会受到腐蚀和更大的孔隙扩散阻力。采用乙醇介质合成、热处理、酸处理和酸热处理等方法解决了上述问题，制备了几种不同nZVI与活性炭质量比的复合材料。对制备的复合材料进行了表征，并应用于批量去除硝酸盐（200 mg NO3-/L）、磷酸盐（50 mg PO43—P/L）和硝酸盐-磷酸盐混合物的实验。在25种复合材料中，选择AC负载的nZVI (F(1)(2)AT(2)(950))，最佳nZVI/AC质量比为2:1，处理条件为950℃，处理时间为2 h。本研究在负载nZVI之前对AC进行热处理，改性AC的结构和表面化学性质，以吸引对nZVI具有更高亲和力的污染物阴离子。F(1)(2)AT(2)（950）复合材料成功地将硝酸盐的去除率提高了50%，磷酸盐的去除率提高了100%，硝酸盐的去除率提高了170%，同时完全去除了溶液中的磷酸盐。在实际现场应用中进行了干扰研究。在硬度、腐植酸、磷、硫酸盐离子、生活废水和亚铜离子存在的情况下对该复合材料进行了测试。根据铜化合物的浓度和类型，后一种干扰可使去除率提高约10-50%。该复合材料在环境废水和地下水技术中具有广阔的应用前景。(C) 2016 Elsevier B.V.版权所有
Supported nano-scale zero-valent (nZVI) iron is a suitable material for groundwater and wastewater treatment applications. It can prevent the agglomeration of nanoparticles and increase their hydraulic conductivity. However, these supported nZVI particles suffer corrosion and greater pore diffusion resistance. Synthesis in ethanol medium, thermal treatment, acid treatment and acid thermal treatment were applied to deal with these problems and produce several treated composites of different nZVI to activated carbon (AC) mass ratios. Produced composites were characterized and applied in batch experiments to remove nitrate (200 mg NO3-/L), phosphate (50 mg PO43--P/L) and a mixture of nitrate and phosphate from their aqueous solutions. Among 25 composites, AC-supported nZVI (F(1)(2)AT(2)(950)) was selected at optimum nZVI/AC mass ratio of 2:1 and treatment conditions of 950 degrees C for 2 h. This study introduced thermal treatment of AC before supporting nZVI, which modified its textural and surface chemistry properties to attract contaminant anions with a higher affinity towards nZVI. F(1)(2)AT(2)(950) composite succeeded to increase removal efficiency of nitrate by 50% and of phosphate by 100% from their aqueous solutions and of nitrate by 170% along with a complete removal of phosphate from their solution. Interference studies were executed for actual field applications. The novel composite was tested in the presence of hardness, humic acid, phosphorus, sulfate ions, domestic wastewater and cuprous and cupric ions. The latter interference enhanced the removal efficiencies by about 10-50% according to concentrations and the type of copper compounds. The novel composite can be implemented as a promising reagent in environmental wastewater and groundwater technologies. (C) 2016 Elsevier B.V. All rights reserved.