Abstract:

The degradation of methylene blue(MB) in water under dark reactions with graphitic carbon/persulfate (g-C₃N₄/PS) in the heterogeneous system was investigated. The results showed that illumination was not a necessary condition for reaction. The degradation of MB could reach 92.86% within 10 min and the degradation rate still stable at more than 90% in 60 min, under the condition that initial pH of the solution was 5, reaction temperature was room temperature(30℃), dosage of g-C₃N₄ was 0.8 g/L, dosage of PS was 0.5 g/L, and under the dark reaction conditions. Free radical trapping experiments showed that·OH, SO₄^·-, h⁺ and O₂^·- were all active substances involved in the degradation of MB by g-C₃N₄/PS dark reaction, and their degree of action decreased in turn. After the catalyst was used for 4 times, the material properties were stable and the MB removal rate was still above 85%.

Key words: Graphitic carbon nitride, persulfate, dark reaction, dyestuffs wastewater

摘要：

采用石墨相氮化碳（g-C₃N₄）和过硫酸盐（PS）的异相体系，在暗反应条件下处理亚甲基蓝印染废水（MB）。结果表明：光照不是反应发生的必要条件，暗反应条件下，溶液初始pH为5、反应温度为室温（30℃）、g-C₃N₄投加量为0.8 g/L、PS投加量为0.5 g/L时，反应10 min MB降解率可达92.86%，60 min降解率仍稳定在90%以上。通过自由基捕获实验，确定·OH、SO₄^·-、h⁺与O₂^·-均为参与g-C₃N₄/PS暗反应降解MB的活性物质，其作用程度依次降低。催化剂循环使用4次后性质稳定，对MB去除率仍在85%以上。

关键词: 石墨相氮化碳, 过硫酸盐, 暗反应, 染料废水

CLC Number: 

• X703