含铬革屑生物炭活化过硫酸盐降解亚甲基蓝

Persulfate Activation by Chrome Shavings Derived Biochar for Methylene Blue Degradation

以制革固体废弃物含铬革屑为原料,在高温限氧条件下制备得到了含铬革屑生物炭(Cr_(2)O_(3)-BC),并探究了其活化过硫酸盐(PS)降解水中亚甲基蓝(MB)的性能。结果表明,在Cr_(2)O_(3)-BC的质量浓度为0.03 g/L、PS的浓度为10 mmol/L的条件下,Cr_(2)O_(3)-BC/PS体系对MB的去除率和矿化率可在30 min内分别达到99.9%和92.1%。在Cl^(-)、NO_(3)^(-)、HCO_(3)^(-)和腐殖酸的干扰下,体系中MB的去除率仍维持在80%以上。此外,循环实验进行6次后,Cr_(2)O_(3)-BC/PS体系对MB的去除率仍高达84.6%。淬灭实验表明,Cr_(2)O_(3)-BC/PS体系中产生的SO_(4)^(·)-和·OH均参与降解MB,且SO_(4)^(·)-起主导作用。该研究不仅为含铬革屑的高值化利用提供了新的思路,而且开发了一种可以去除废水中MB的高效PS催化剂,实现了以废治废的循环经济理念。

Chrome shavings were used as raw materials to prepare the Cr-containing biochar(Cr_(2)O_(3)-BC)via a pyrolysis process under the nitrogen atmosphere,and its performance for persulfate(PS)activation was studied using methylene blue(MB)as the model pollutant.Results illustrated that high removal rate(99.9%)and high mineralization efficiency(92.1%)of MB could be achieved within 30 min with PS concentration of 10 mmol/L and Cr_(2)O_(3)-BC dosage of 0.03 g/L.Besides,the coexisting substances(e.g.Cl^(-),NO_(3)^(-),HCO_(3)^(-)and humic acid)played a little effect on the MB removal,and more than 80%of MB still could be degraded in the Cr_(2)O_(3)-BC/PS system.In addition,the MB removal rate still reached 84.6%after six cycles of Cr_(2)O_(3)-BC/PS.Quenching experimental results indicated that both SO_(4)^(·)-and·OH were responsible for the MB removal in the Cr_(2)O_(3)-BC/PS system,but SO_(4)^(·)-played the dominant role.Hence,this work not only provided a feasible strategy for the high-value use of chrome shavings,but also developed an efficient catalyst for PS activation to remove MB,which is in line with the concept of circular economy.