新穎材料農業：友善環境農業新穎材料研發與安全評估【土環系劉雨庭副教授】
論文篇名 英文：Removal and simultaneous reduction of Cr(VI) by organo-Fe(III) composites produced during coprecipitation and coagulation processes
中文：共沉澱和混擬過程中產生的有機質-鐵複合物去除並同時還原六價鉻
期刊名稱 Journal of Hazardous Materials
發表年份,卷數,起迄頁數 2019, 376: 12-20
作者 Chen, K.Y., Tzou, Y.M., Chan, Y.T., Wu, J.J., Teah, H.Y., Liu, Y.T.*
DOI 10.1016/j.jhazmat.2019.04.055
中文摘要 在自然水體和廢水系統中，普遍的可溶性有機質和鐵在共沉澱或混擬過程中形成的複合物可能是吸附和還原六價鉻的潛在清除劑。本篇研究目的為探討在不同共沉澱的pH值及碳鐵比下，有機質-鐵複合物吸附和還原六價鉻的機制。結果顯示，在pH 3及碳鐵比0.71所共沉澱的有機質-鐵複合物中，鉻的最大吸附量為51.8 毫克/克。其中，在共沉澱後移除六價鉻的機制主要為吸附在鐵氫氧化物上。隨著碳鐵比的增加，總鉻吸附量減少，但是六價鉻還原量的增加則補償了在高碳鐵比下有機質-鐵複合物的六價鉻移除能力。當碳鐵比 ≥0.89時，共沉澱之有機質的增加並與鐵域均勻分佈在有機質-鐵複合物表面上可能會導致顯著的六價鉻還原量。總結來說，本研究結果提出了以控制懸浮液中碳鐵比來替代六價鉻汙染復育的另一種方法。在鐵氫氧化物吸附大多數的六價鉻後，提高系統中的碳鐵比可以將剩餘的六價鉻還原為三價鉻來進一步提高六價鉻的總移除率。
英文摘要 Composites formed during the coprecipitation and/or coagulation of ubiquitous dissolved organic matter (DOM) and Fe in natural and waste water systems might be potential scavengers for Cr(VI) in terms of sorption and reduction. Our objective here was to determine sorption and simultaneous reduction of Cr(VI) on organo-Fe(III) composites (OFC) in relation coprecipitated pH and C/(C   Fe) ratios. Results showed the greatest Cr sorption of 51.8 mg g-1 on the OFC sample that was precipitated at pH 3 and contained the C/(C   Fe) molar ratio of 0.71. Wherein the Cr(VI) removal subsequent to the coprecipitation was dominated by the sorption on Fe hydroxides. Although amounts of total sorbed Cr decreased with increasing C/(C   Fe) molar ratio, the reverse trend on Cr(VI) reducibility compensated the Cr(VI) removal capability of OFC samples. With C/(C   Fe) molar ratios ≥ 0.89, the increasing amounts of coprecipitated organic matter that homogeneously distributed with Fe domains on OFC surfaces could trigger a significantly pronounced Cr reduction. Collectively, our results suggested an alternative method for Cr(VI) remediation by manipulating C/Fe ratios in suspensions. After the sorption of most Cr(VI) on Fe hydroxides, increasing C/Fe ratio in systems could further improve the Cr(VI) removal efficiency by the reduction of remaining Cr(VI) to Cr(III).