低温等离子体耦合生物滴滤处理拜耳法生产氧化铝溶出过程中VOCs的研究

Study on low-temperature plasma coupled biological trickling filtration for treatment of VOCs in the Bayer digestion process to produce alumina

国内铝土矿拜耳法管道化溶出过程中的不凝性乏气含有多成分、高含量的挥发性有机物(VOCs)。在某河南氧化铝厂进行工业中试,利用低温等离子体耦合生物滴滤进行工业试验,使用气相色谱质谱联用及便携式甲烷非甲烷总烃分析仪进行定量分析。并探究低温等离子体耦合生物滴滤去除拜耳法生产氧化铝溶出过程中VOCs不同初始浓度、不同进气温度、不同放电组数及不同停留时间对去除效果的影响。结果表明,初始进口VOCs浓度最高可达1308 mg/m^(3)时,耦合技术去除量可达到1270.30 mg/m^(3),去除效率为97.11%。VOCs浓度高于800 mg/m^(3)时,可调节低温等离子体放电组数为3组。生物滴滤法中微生物适宜的生化降解温度为20~30℃,最佳气体停留时间为120 s。

The non-condensable exhaust gas from the domestic Bayer tube digestion process contains multi-component high-content volatile organic compounds(VOCs).An industrial pilot test was carried out in a Henan alumina refinery,the low-temperature plasma coupled biological trickling filtration was used for the industrial test,and the gas chromatography mass spectrometry coupled with a portable methane non-methane total hydrocarbon analyzer was used for quantitative analysis.The effect of different initial concentration of VOCs,different inlet temperature,different number of discharge groups,and different residence time was studied on the removal effect of VOCs from the Bayer digestion process to produce alumina with the low-temperature plasma coupled biological trickling filtration.The results show that when the initial VOCs concentration is as high as 1308 mg/m^(3),the coupling removal rate can reach 1270.30 mg/m^(3),and the removal efficiency can reach 97.11%.When the VOCs concentration is higher than 800 mg/m^(3),the number of adjustable low-temperature plasma discharge groups is 3.The suitable biochemical degradation temperature of microorganisms in biotrickling is 20~30℃,and the optimal gas residence time is 120 s.