基于UV-Vis吸收光谱的UDMH催化降解中间产物

为了研究偏二甲肼(UDMH)在Cu~(2+)/H_2O_2和Fe~(2+)/H_2O_2两种氧化体系中的降解效能及机理,研究了体系pH、温度、时间、氧化剂投加量四种因素对废水中偏二甲肼降解率的影响,利用紫外-可见光谱方法解析了氧化降解产物。重点对比分析pH为3,5,7,9时偏二甲肼在两种体系中的降解产物,探讨了偏二甲肼的降解氧化机理,结果表明:温度和氧化剂投加量对偏二甲肼的降解率影响不大,体系pH对偏二甲肼降解率影响显著,pH是控制偏二甲肼降解生成物种类的主要因素,Cu~(2+)/H_2O_2与Fe~(2+)/H_2O_2体系中偏二甲肼降解生成产物种类相似,酸性条件下产物少于较碱性和中性条件。Cu~(2+)/H_2O_2体系处于碱性条件时,对偏二甲肼的降解率较高但中间产物较多;Fe~(2+)/H_2O_2处于酸性条件时,降解效率高且中间产物较少。

Intermediate Products of Unsymmetrical Dimethylhydrazine Catalytic Degradation by UV-Vis Spectroscopy

The two oxidative systems of Cu²⁺/H₂O₂ and Fe²⁺/H₂O₂ were adopted to degrade unsymmetrialdimethy hydrazine (UDMH) wastewater to study degradation efficiency and mechanism, and the impacts of the four factors: pH value, temperature, time and oxidant dosage on the degradation rate of UDMH wastewater were studied. UV-vis method was applied to analyze the oxidative degradation products of UDMH. The mechanism of oxidative degradation of UDMHwas discussed, and the degradation products of two systems at pH 3,5, 7,9 were comprehensive comparative analyzed. Results show that the two factors temperature and oxidant dosage have little effect on the degradation rate of UDMH, but pH has great influences on the degradation rate of UDMH and pH is the main factor controlling the type of degradation products of UDMH. The systems of Cu²⁺/H₂O₂ and Fe²⁺/H₂O₂ have the similar degradation products, which are less produced under acidic condition than alkali and neutral conditions. The system of Cu²⁺/H₂O₂ has a relatively high degradation rate on UDMH but many in-process products under alkali condition, and the system of Fe²⁺/H₂O₂ has high degradation efficiency and few in-process products under acidic condition.