木薯全糟是一种高浓度、高含固的有机废水，现阶段主要利用厌氧消化工艺，净化水质的同时回收生物气。为了进一步合成高值化产品，研究了木薯酒精废水厌氧产酸的可行性，着重考察了木薯酒精废水不溶性固体的厌氧产酸特性。研究发现，木薯全糟在常温厌氧条件下相比木薯清液具有一定的产酸潜能，第一批发酵9天后 VFA(Volatile Fatty Acids)产量达29000 mgCOD×L-1，但是后续两批无法利用不溶性固体进行厌氧发酵产酸。采用超声、热、碱和热碱联合分别对全糟进行预处理，可以降低不溶性固体物质中的木质素含量，增加纤维素含量，但是预处理前后厌氧发酵的产酸量基本相当。对糖及蛋白质的降解研究发现，这部分增加的纤维素并没有被产酸细菌所利用，在厌氧发酵中对 VFAs的产生贡献不大。建议木薯酒精废水应先固液分离后，再进行常温厌氧产酸，从而减少后续发酵装置的体积和基建投资。%Cassava Stillage (CS) has high organic and suspended solids (SS) contents and is mainly used in anaerobic digestion and biogas recovery. This study focused on the feasibility of anaerobic acidification of CS, and the characteristics of the anaerobic acidification process was investigated. The results show that CS has higher VFAs production potential than cassava supernatant under anaerobic and room temperature conditions. The VFAs yield was 29000 mgCOD×L-1 in the first batch after 9 days of fermentation, but the second and third batches only reached 6000mg COD×L-1 and 3000mg COD×L-1, respectively. Four different pretreatments (ultrasonication, high temperature, alkali, hot-alkali) can promote hydrolysis process and increase cellulose contents, but the VFAs yield is not improved, which indicates that the cellulose makes little contribution to VFAs production. Solid-liquid separation before anaerobic acidification should be considered to decrease reactor volume and infrastructure investment.
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