pH调节方法对厨余垃圾两相厌氧消化中水解和酸化过程的影响

通过间歇实验探讨了pH调节方法对厨余垃圾两相厌氧消化中水解酸化过程和水解酸化液中Na 浓度的影响实验比较了厨余垃圾在3种pH调节方法(利用NaOH溶液调节初始进料pH到7,利用NaOH和Ca(OH)2混合碱液每12h调节pH到7和利用调节C/N比调节pH到7)下水解酸化液中的Na 浓度、一级水解速率常数、挥发酸(VFA)浓度、乳酸浓度和VFA组分分配.结果表明,与利用NaOH溶液每12 h调节pH相比较,3种pH调节方法都能够有效降低水解酸化出料液中的Na 浓度,但利用调节C/N比来调节pH能够取得更高的水解酸化效率,一级水解速率常数可以达到0.199 d-1,VFA浓度在实验第3天即可达到35 g·L-1.发酵产物乳酸在实验第2天即达到高峰浓度24 g·L-1,后逐渐下降到6 g·L-1,VFA组分中丙酸不是优势组分.

The influence of pH adjustment methods on hydrolysis and acidogenesis of kitchen wastes in two-phase anaerobic digestion

Batch experiments were carried out to determine the effect of pH adjustment methods on the accumulation of Na+ in the effluent, hydrolysis and acidogenesis of kitchen wastes in the two-phase anaerobic digestion. Three pH adjustment methods included the initial adjustment of pH using NaOH, batch pH adjustment using NaOH and Ca(OH)2 and the pH adjustment with regulating the ratio of carbon and nitrogen. The results showed that the effluent Na+ concentration in the hydrolysis-acidogenesis liquid could be reduced at three pH adjustment methods. However, compared to the other two pH adjustment methods, the pH adjustment method with regulating the ratio of carbon and nitrogen increased the hydrolysis and acidogenesis rates of kitchen wastes with the first-order hydrolysis rate constant of 0.199d-1 and VFA concentration of 35g?L-1. The lactic acid concentration decreased to 6g?L-1 after the maximum lactic acid concentration of 24 g?L-1 was achieved on the second day of the experiment. And the propionic acid didn't predominate over the VFA constituents.