School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200433, China.
Aix-Marseille Univ, CNRS, IRD, INRAE, CEREGE, Avenue Louis Philibert, Aix en Provence, 13100, France.
Chemosphere. 2022 Nov;307(Pt 3):135686. doi: 10.1016/j.chemosphere.2022.135686. Epub 2022 Aug 4.
Pollution of wastewater and natural waters by organic contaminants is a major health issue, yet actual remediation methods are limited by incomplete removal of recalcitrant contaminants and by secondary pollution by chlorinated contaminants and catalytic metals. To attempt to solve these issues, we tested the removal of acid orange by peracetic acid (PAA), a safe oxidant, activated by Fe-biochar that iron anchored on biochar to prevent secondary pollution by iron. Fe-biochar was synthesized using a simple, one-step pyrolysis method. We investigated the effects of PAA concentration, pH, humic acids, chloride, bicarbonate on the reaction. Radical quenching and electron paramagnetic resonance were used to identify reacting species. Results showed that the granulous structure of Fe-biochar and the presence of Fe, FeO, FeO, and FeC on Fe-biochar surface. The highest removal of acid orange of 99.9% was obtained with 1.144 mM PAA and 0.3 g/L Fe-biochar at pH 7. Acid orange removal increases with Fe-biochar dose, decreases with pH, is slightly inhibited by humic acids and bicarbonate, and is not modified by chloride. Our experimental results suggested that CHC(O)OO· and CHC(O)O· are the main radical species, but there may also be non-radical effects in Fe-biochar/PAA process. Fe-biochar displayed high re-usability, with 92.8% removal after five uses.
有机污染物对废水和天然水的污染是一个主要的健康问题，但实际的修复方法受到顽固污染物去除不完全和氯化污染物和催化金属的二次污染的限制。为了尝试解决这些问题，我们测试了过乙酸 (PAA) 对酸性橙的去除效果，过乙酸是一种安全的氧化剂，由铁生物炭激活，铁锚定在生物炭上以防止铁的二次污染。铁生物炭是通过简单的一步热解方法合成的。我们研究了 PAA 浓度、pH 值、腐殖酸、氯离子、重碳酸盐对反应的影响。自由基猝灭和电子顺磁共振用于鉴定反应物种。结果表明，铁生物炭的颗粒结构以及铁生物炭表面存在 Fe、FeO、FeO 和 FeC。在 pH 值为 7 时，用 1.144 mM PAA 和 0.3 g/L 铁生物炭可获得最高的酸性橙去除率 99.9%。酸性橙的去除率随铁生物炭剂量的增加而增加，随 pH 值的降低而降低，受腐殖酸和重碳酸盐的轻微抑制，不受氯离子的影响。我们的实验结果表明，CHC(O)OO·和 CHC(O)O·是主要的自由基物种，但在铁生物炭/PAA 过程中也可能存在非自由基效应。铁生物炭表现出很高的可重复使用性，重复使用五次后仍可去除 92.8%的酸性橙。
