电化学氧化与生物法联合降解木质素的影响因素

Influencing factors of lignin degradation by combination of electrochemical oxidation and biodegradation

采用高效的电化学氧化技术联合低成本的生物降解技术,进行了木质素的降解探索。考察了电流密度、电量、初始p H和电解质浓度对木质素降解效果的影响,结果表明,电流密度和电量影响显著,而初始p H和电解质浓度的影响较小。经过综合比较,得到电化学与生物联合降解木质素的最佳反应条件为:电流密度为5.0 m A/cm2;电量为20 k C;初始p H为7;电解质浓度为0.1 mol/L。在此条件下,碱木质素和木质素磺酸钠的COD去除率分别达到65.97%和59.31%,表征木质素酚羟基结构的UV280分别降低了65.97%和59.77%,色度去除率分别为74.15%和58.32%。总之,电化学前处理可破坏木质素的关键结构,提高木质素的可生化性,从而促进加快后续生物降解。

Lignin degradation by combining electrochemical oxidation（ EO） with biodegradation（ BD） was studied. The effects of four factors such as current density,electronic quantity,p H value,and concentration of the supporting electrolyte on lignin degradation were analyzed. The results showed that current density and electronic quantity had much more important impacts on lignin degradation than the p H value and concentration of the supporting electrolyte. Through comparison,the optimum conditions for ligning degradation were confirmed ascurrent intensity of 5. 0 m A / cm2,electric quantity of 20 k C,p H of 7,and concentration of supporting electrolyte of 0. 1 mol / L. For kraft lignin and lignosulfonate degradation,COD removal rates of 65. 97% and 59. 31%,UV280 reduction of 65. 97% and 59. 77%,and color removal efficiencies of 74. 15% and 58. 32% were obtained. It was confirmed that EO could destroy the recalcitrant bonding structure of lignin to produce biodegradable intermediates that could be removed easily by further bioprocesses.