CaO2 has been widely used as an oxygen-releasing material in bioremediation to improve the aerobe activity, but conventional encapsulation methods are difficult to control the oxygen-releasing rate and realize the full conversion of CaO2. In this work, innovative biochar-loaded CaO2 was prepared by an in-situ precipitation method. The biochars were modified using base-/acid-treatment to establish the relationship between the biochar properties and the oxygen releasing performance. Results indicated that increasing the oxygen content of biochars from 11% to 12% to ∼20% caused a significant rise in CaO2 loading amount from ∼6 wt% to 13–14 wt%. The biochar with an average pore size equivalent to CaO2 nanoparticle sizes (∼12 nm) exhibited the longest oxygen-releasing time of 7.5 d, while the others presented shorter releasing periods of < 2.4 d. Meanwhile, a higher oxygen content of biochar triggered a decrease in the oxygen-releasing amount. Results from bioremediation experiments indicated that when comparing with the pure CaO2 material, the optimized loading material (CaO2 @BC800) nearly doubled the amount of bacteria while negligibly changed the pH of solution, giving a significant increase in the removal of diesel oil pollutant. Correspondingly, the in-situ loading on biochar can facilely regulate the oxygen-releasing performance and enhance the removal efficiency of bioremediation.

中文翻译：

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创新碳基 CaO2 材料的受控合成，在水环境中具有更高的氧释放性能


CaO2 在生物修复中被广泛用作释氧材料以提高需氧活性，但传统的包埋方法难以控制释氧速率和实现 CaO2 的完全转化。在这项工作中，通过原位沉淀法制备了创新的生物炭负载 CaO2。使用碱/酸处理对生物炭进行改性，以建立生物炭特性与释氧性能之间的关系。结果表明，将生物炭的氧含量从 11% 增加到 12% 再到 ∼20% 导致 CaO2 负载量从 ∼6 wt% 显着增加到 13-14 wt%。平均孔径与 CaO2 纳米粒径 （∼12 nm） 相当的生物炭表现出最长的氧释放时间，为 7.5 d，而其他生物炭的释放时间较短，为 < 2.4 d。同时，生物炭的氧含量较高导致氧释放量减少。生物修复实验结果表明，与纯 CaO2 材料相比，优化的负载材料 （CaO2 @BC800） 使细菌数量几乎增加了一倍，而溶液 pH 值的变化可以忽略不计，从而显著提高了柴油污染物的去除率。相应地，生物炭上的原位负载可以方便地调节氧释放性能，提高生物修复的去除效率。