摘要
短链挥发性脂肪酸(volatile fatty acids,VFA),如乙酸和丙酸,是高碳氮比海水养殖废水处理时更易利用的碳源,对剩余污泥进行恰当预处理是其后续厌氧发酵获得优质短链脂肪酸的关键.本研究分别运用加热水解和鼠李糖脂水解对剩余污泥进行预处理,继而厌氧发酵,通过检测溶解性有机质(SCOD、多糖和蛋白)、胞内水解酶活性、短链VFA以及氨氮等指标特征,探究预处理技术对短链脂肪酸尤其是乙酸和丙酸单位产量的影响.结果表明,65℃、2 h加热水解预处理能促进污泥中VFA的溶出和发酵过程中碳源的转化,剩余污泥厌氧发酵3 d时,产生的VFA是无预处理组的2倍,乙酸是优势产物;鼠李糖脂水解的剩余污泥,发酵8 d时产生的VFA是无预处理的4倍,丙酸是优势产物.相比丙酸而言,乙酸是反硝化脱氮、微生物燃料电池(MFC)更好的碳源.因此,从VFA组成类型、发酵时间以及应用的可行性等考量,加热水解是一种相对经济可行的促进剩余污泥发酵制取优质脂肪酸的预处理方式.
Short-chain volatile fatty acids(VFA),such as acetic acid and propionic acid,are the preferred carbon sources for the treatment of high C/N ratio mariculture wastewater.Appropriate pretreatment of excess sludge is a key step to obtain high-quality short-chain fatty acids during the following anaerobic fermentation process.In this study,the excess sludge was first pre-treated by two different methods,i.e.thermal hydrolysis and rhamnolipid,and then the products were subjected to anaerobic fermentation.The pretreatment performance was investigated by detecting the dissolved organic matter(SCOD,polysaccharide and protein),intracellular hydrolytic enzyme activity,VFA,ammonia nitrogen and macromolecular organics.The results showed that the pretreatment of the excess sludge at 65℃ for 2 h could promote the production of VFA and transformation of carbon source during the anaerobic fermentation.When thermal-hydrolysis excess sludge was fermented anaerobically for 3 days,the amount of VFA reached two times that of non-pretreated sludge and acetic acid was the dominant product.The amount of VFA,as the sludge was pretreated by rhamnolipid,was four times that of non-pretreated sludge after 8 days of fermentation and propionic acid was the dominant product.Compared with the propionic acid,the acetic acid was more favorite carbon source for the denitrifying and microbial fuel cells.Therefore,considering the VFA composition and fermentation time,thermal hydrolysis is relatively economical and feasible pretreatment method to promote the fermentation of excess sludge to produce high-quality fatty acids.
作者
陈乙平
赵阳国
郭亮
CHEN Yiping;ZHAO Yangguo;GUO Liang(College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100;Key Laboratory of Marine Environmental Science and Ecology,Ocean University of China,Ministry of Education,Qingdao 266100)
出处
《环境科学学报》
CAS
CSCD
北大核心
2020年第3期1004-1010,共7页
Acta Scientiae Circumstantiae
基金
中央高校基本科研业务费专项(No.201964004)
