矿物材料预处理对餐厨垃圾高温厌氧消化过程的影响

Effect of mineral pretreatment on thermophilic anaerobic digestion of food waste

选用4种矿物材料对400g餐厨垃圾在35℃下进行4h好氧预处理,比较了预处理前后餐厨垃圾水解率的变化,并且详细研究了预处理对餐厨垃圾高温厌氧消化过程及产沼气效果的影响.结果表明:在同等条件下,添加矿物材料可以有效促进餐厨垃圾的水解,其中添加1.25%(质量分数,以餐厨垃圾湿基计)膨润土和添加2.5%轻烧MgO的处理水解率分别达到了96.79%和96.51%.轻烧MgO有效地缓解了餐厨垃圾由于酸化引起的pH值下降,使产气高峰期较早来到;而在总产气量上添加白云石粉的促进作用显著,膨润土次之,其中添加2.5%白云石粉的总产气量最高,为10925mL.添加矿物材料降低了消化液中钠离子的浓度,可减轻对产甲烷细菌的抑制作用.

Food wastes were pretreated aerobically with four different minerals（bentonite,light burned magnesia,coal ash and burned dolomite）for four hours at 35℃.The effects of the different minerals on hydrolysis rate and on thermophilic anaerobic digestion were studied in detail.The results showed that the hydrolysis of food wastes was accelerated by the addition of the minerals.The hydrolysis rates were 96.79% and 96.51% with the addition of 1.25%（w/w,based on 400 g food wastes）bentonite and 2.5% light-burned magnesia,respectively.The decrease of pH value due to acidification was controlled with the addition of light-burned magnesia and the aerogenical peak appeared earlier.Considering total biogas production,the highest promotion was observed in the treatment with burned dolomite,followed by bentonite.The greatest biogas production was 10925 mL with the addition of 2.5% burned dolomite.Moreover,the inhibition of sodium on methanogens was mitigated by the decreased concentration of sodium ion after adding minerals to the digestion system.