Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Jimei District, Xiamen, Fujian, 361021, China.
College of Chemical Engineering, Huaqiao University, Xiamen, 361021, China.
Environ Geochem Health. 2019 Aug;41(4):1755-1766. doi: 10.1007/s10653-017-9984-8. Epub 2017 May 26.
Arsenic-containing water poses a serious threat to human health. In this study, two types of Fe-modified rice straw biochars [(Fe-impregnated biochar (FeIm char) and pre-modified rice straw biochar (PMRS char)] were prepared, in which three ratios [1, 5, and 10% (w/w)] of Fe modification were evaluated, resulting in six different Fe-modified biochars. Then, a series of adsorption experiments, using single- and binary-metal solutions of As(V) and Cd(II), were conducted to investigate the performances of modified biochars on metal adsorption compared to pristine rice straw biochar (RS char). Results indicated Fe modification improved the As(V) adsorption capacity of biochar. PMRS char showed higher adsorption of As(V) than FeIm char. At the 5% Fe modification ratio (FMR), the As(V) removal by PMRS char (at 10 g/L dosage) from 100 mg/L As(V) solution was approximately 69.6%, which was higher than 46.1% of FeIm char or 22.6% of RS char. In contrast, the adsorption of Cd(II) was decreased after modified at 5 or 10% FMR. Interestingly, for treating solution containing As(V) and Cd(II) together, the adsorption of As(V) onto FeIm char or PMRS char prepared at 5 or 10% FMR remained higher than that onto RS char, while the simultaneous removal of Cd(II) ion by either modified biochar was kept over 50%. Thus, the finding of this study suggested Fe-modified biochars, especially prepared via the pyrolysis of FeCl pre-soaking rice straw, could be a promising adsorbent for the remediation of complex As(V)-containing wastewater.
含砷水对人类健康构成严重威胁。在这项研究中，制备了两种类型的 Fe 改性稻草生物炭[（Fe 浸渍生物炭（FeIm 炭）和预改性稻草生物炭（PMRS 炭）]，其中评估了三种 Fe 改性比例[1、5 和 10%（w/w）]，从而得到六种不同的 Fe 改性生物炭。然后，使用单金属和双金属溶液（As(V)和 Cd(II)）进行了一系列吸附实验，研究了改性生物炭对金属吸附的性能，与原始稻草生物炭（RS 炭）相比。结果表明，Fe 改性提高了生物炭对 As(V)的吸附能力。PMRS 炭对 As(V)的吸附作用高于 FeIm 炭。在 5% Fe 改性比例（FMR）下，PMRS 炭（在 10 g/L 剂量下）从 100 mg/L As(V)溶液中去除约 69.6%的 As(V)，高于 FeIm 炭的 46.1%或 RS 炭的 22.6%。相比之下，在 5 或 10% FMR 下改性后，Cd(II)的吸附减少。有趣的是，对于处理同时含有 As(V)和 Cd(II)的溶液，在 5 或 10% FMR 下制备的 FeIm 炭或 PMRS 炭对 As(V)的吸附仍高于 RS 炭，而改性生物炭对 Cd(II)离子的同时去除率仍保持在 50%以上。因此，本研究的结果表明，Fe 改性生物炭，特别是通过 FeCl 浸泡稻草的热解制备的生物炭，可能是一种有前途的修复含复杂 As(V)废水的吸附剂。
