壳聚糖负载磺化酞菁钴催化过硫酸盐降解甲基橙的研究

过渡金属催化过硫酸盐（PS）产生活性氧自由基（ROS）可有效降解有机污染物.为避免均相催化过程中过渡金属带来的二次污染，将磺化酞菁钴（CoPcS）键合固定于壳聚糖（CS）微球载体上，制备出一种结构稳定、较高催化活性的催化剂（CS-CoPcS），并以偶氮染料甲基橙（MO）为目标污染物，考察不同反应条件对MO降解过程的影响，进而分析了催化剂的稳定性和降解机理.结果表明：CS-CoPcS催化PS可有效降解MO，当反应温度为25℃，MO初始浓度为152.75μmol/L，pH₀为5.5，PS的投加浓度为10mmol/L，CS-CoPcS投加量为1.25g/L，MO在180min的降解率可达87.21%，降解速率为1.24×10^-2min^-1，符合准一级动力学方程；电子自旋共振（EPR）和淬灭实验均证实催化过程产生以硫酸根自由基为主的有效ROS；4次循环利用实验中未能检测出溶液中潜在浸出的钴离子，CS-CoPcS表现出很好的催化活性和结构稳定性.

Degradation of methyl orange by chitosan microsphere supported cobalt tetrasulfophthalocyanine activated persulfate

Oxygen radicals (ROS) generated by transition metals catalysed activation of persulfate (PS) can be applied to degrade various organic pollutants. In order to avoid related second pollution of heavy metal under homogeneous catalytic system, a stable and effective catalyst (CS-CoPcS) was developed for PS activation by immobilizing cobalt tetrasulfophthalocyanine (CoPcS) onto chitosan (CS) microspheres covalently for the heterogeneous catalytic degradation of azo dye methyl orange (MO). The effects of different reaction conditions were studied. Furthermore, the stability of CS-CoPcS and possible mechanism were analyzed. The results showed that the MO removal efficiency could up to 87.21% at 25℃ under the conditions of initial MO concentration of 152.75mmol/L, pH₀ value of 5.5, PS concentration of 10mmol/L and CS-CoPcS dosage of 1.25g/L. The kinetics data were fitted very well by pseudo-first-order model in 180min, and the removal rate was 1.24×10^-2min^-1. The comparison of the electron paramagnetic resonance (EPR) and different radical scavengers effect showed that sulfate radical was the dominant active species in the catalytic process. The results of recycling experiments after four runs indicated that the CS-CoPcS was recyclable for consecutive catalytic degradation of MO, and no detectable amount of cobalt ion in the aqueous solution after any runs reaction, which show high catalytic activity and structural stability of CS-CoPcS.