草浆黑液厌氧处理过程中钠的抑制作用研究

Sodium Inhibition Effect on the Anaerobic Process for Caustic Soda Straw-pulping Black Liquor Treatment

本文研究了烧碱法草浆黑液中主要钠盐——木素钠、硅酸钠、硫酸钠以及作为对照的氯化钠在厌氧过程中的抑制特性。这些钠盐按半抑制浓度的抑制作用强度排序为:氯化钠>木素钠>硫酸钠>硅酸钠。相对产甲烷率P_M(I)(%)和钠浓度I[g(Na)/L]的关系可用式P_M(I)=[1+(I/K_i)~α]^(-1)进行拟合。污泥经过驯化,对钠的耐受能力可以提高。本项目是探索黑液低倍稀释或不稀释进行厌氧处理的一项基础研究。

The black liquor from caustic soda straw-pulping process contains high concentration of sodium salts, which usually in the range of 17—24 g/L is the major inhibitant in the anaerobic biological process for black liquor treatment. For the purpose of comparison, lignin sodium, Na_2SiO_3 and Na_2SO_4 the major sodium salts in the black liquor, and NaCl as reference salt, are selected as inhibitants in batch experiments to investigate the sodium inhibition characteristics in tha anaerobic treatment process. According to their 50％ inhibition concentrations, the order of inhibition strength for these four sodium salts is: NaCl>lignin sodium>Na_2SO_4>Na_2SiO_3. A kinetic model of P_M(I)=[1+(I/K_i)~a]^(-1) is suggested to describe the relationship between the relative CH_4 production rate P_M(I) (％) and sodium concentration I(g(Na)/L). The anaerobic suspended sludge acclimated with Na^+ for a period can work normally under the sodium concentration of 6000 mg/L in diluted black liquor.