环境工程水处理实验教学探索与实践

水处理实验教学是高校环境工程专业实验课程的重要组成部分。随着培养目标要求不断提升,传统水处理实验教学在内容和方法上逐渐暴露出一些问题,如实验条件不足、教学形式单一、实验内容简单、考核体系不全面等。这些问题严重阻碍了学生实践和创新能力的培养。针对以上问题,结合专业实际情况,分析江南大学环境工程专业在改善实验教学条件、创新实验教学手段、优化实验教学内容、完善课程考核体系四个方面进行的尝试与探索。实践表明,改革后的水处理实验教学质量和学生解决实际问题的能力得到提升,符合人才培养目标的具体要求。

Controllable photochemical synthesis of amorphous Ni(OH)2 as hydrogen production cocatalyst using inorganic phosphorous acid as sacrificial agent

Loading of cocatalysts can effectively inhibit the recombination of photogenerated carriers in photocatalysts and greatly improve the photocatalytic hydrogen production rate. Cocatalysts can be deposited at the outlet points of electrons using a photochemical method, which is beneficial for the following photocatalytic hydrogen production reaction. H2PO2^– has been used in the photochemical reduction of transition metals because of its special properties. However, the particles formed in the presence of H2PO2^– are very large and highly crystalline, which may inhibit the activity of photocatalysts. In this study, we designed a new method for synthesizing photocatalysts by photodeposition using some other phosphates, aiming to prepare controllable weakly crystalline and small-size cocatalysts to improve the hydrogen production activity. The cocatalyst prepared using H2PO3^– as an inorganic sacrificial agent has an amorphous structure and an average size of about 10 nm. The optimal photocatalytic hydrogen production rate of the obtained Ni(OH)2/g-C3N4(4.36 wt%) is 13707.86 μmol·g^-1·h^-1, which is even higher than the activity of Pt-4.36 wt%/g-C3N4(11210.93 μmol·g^-1·h^-1). Mechanistic studies show that loading of Ni(OH)2 can efficiently accelerate the separation and transfer efficiency of photogenerated charge carriers.

硝酸盐对牛粪梭菌甲酸脱氢酶缺失型Wood-Ljungdahl途径固碳的影响

【背景】异于同型产乙酸菌通常利用Wood-Ljungdahl途径将2分子CO_(2)还原为1分子乙酰辅酶A,Clostridium bovifaecis缺失Wood-Ljungdahl途径甲基支路第1步将CO_(2)还原为甲酸的甲酸脱氢酶,需甲酸存在时将1分子甲酸和1分子CO_(2)还原为乙酰辅酶A发生葡萄糖的同型产乙酸型发酵。已有报道显示,硝酸盐也可作为同型产乙酸菌的电子受体,而且对不同同型产乙酸菌的代谢影响有所不同,然而硝酸盐对这种独特的甲酸脱氢酶缺失型Wood-Ljungdahl途径固碳的影响尚不清楚。【目的】探究硝酸盐对C.bovifaecis甲酸脱氢酶缺失型Wood-Ljungdahl途径固碳的影响。【方法】硝酸盐浓度分别为10 mmol/L和30 mmol/L时,以未添加硝酸盐为对照实验,研究C.bovifaecis在葡萄糖+甲酸+CO_(2)为基质条件下的细菌生长、底物消耗和产物生成情况。【结果】10 mmol/L和30 mmol/L硝酸盐存在时,主要产物乙醇浓度分别为5.80 mmol/L和1.66 mmol/L,明显低于对照组的乙醇浓度(7.13 mmol/L),葡萄糖消耗量也明显减少。甲酸盐消耗量随着硝酸盐浓度的升高而降低,硝酸盐浓度为30 mmol/L时甲酸盐无明显消耗。【结论】30 mmol/L的硝酸盐抑制了C.bovifaeciss甲酸脱氢酶缺失型Wood-Ljungdahl途径的固碳作用,10 mmol/L硝酸盐降低了C.bovifaecis葡萄糖的糖酵解作用。