电-Fenton法预处理脱水蔬菜废水研究

采用电-Fenton法处理化学需氧量(CODCr)质量浓度为7378 mg/L的脱水蔬菜废水,考察施加电压、电流密度、电导率、H2O2添加浓度、pH值、处理时间等因素对废水CODCr去除率的影响,探讨了污染物的降解规律及废水经处理后的可生化性.结果表明:在外加电压为16 V,电流密度为10.2 mA/cm2,电导率为23000μs/cm,H2O2浓度为32 mmol/L,pH值为3的条件下,反应20 min,原废水CODCr可降至1771 mg/L,去除率达76%.五日生化需氧量(BOD5)由1992 mg/L下降至845 mg/L,BOD5/CODCr比由0.27增至0.48,废水可生化性明显改善,进一步为生化处理废水创造了良好的条件.

Effect of Refrigerant on Solidification Structure of Steel

By the solidification experiment of a medium carbon steel with refrigerant added.the effect of refrigerant on solidification structure of steel was studied.The results clearly show that refrigerant can increase the ratio of equiaxed crystal,fine grains and decrease central porosity and segregation.