模拟废水高温厌氧消化出水中SMP的特性研究

Characterization of SMP in the effluent of thermophilic anaerobic digestion process treating synthetic glucose wastewater

为考察废水高温厌氧消化出水中溶解性微生物产物(SMP)的特性,采用高温厌氧序批式反应器处理葡萄糖模拟废水,运用尺寸排除色谱(SEC)分离厌氧消化出水溶解性有机物(DOM),结合溶解性有机碳(DOC)、UV254吸光度和三维荧光光谱分析方法,对不同分离组分进行了定性和定量研究.结果表明,SMP在出水DOM(356mg/L,以DOC计)中占90.8%,其在高分子量(MW)(10k^100kDa)、中等MW(1k^10kDa)和低MW(<1kDa)内的含量分别为46.8%、45.4%和7.8%.高MW内的SMP比中等、低MW内的SMP有更高的芳香度.废水高温厌氧消化出水中SMP的荧光物质以高的酪氨酸类物质含量,低的富里酸和腐殖酸类物质含量为主要特征.低MW区域的SMP主要包括酪氨酸类物质,而富里酸和腐殖酸类物质主要集中于中等MW区域,色氨酸类和微生物副产物类物质在各MW区域内均有分布.高、中等MW区域(不含630Da<MW<4kDa部分)内的荧光物质组成并无显著差异,但色氨酸和微生物副产物类物质的结构形态则产生了变化.

A thermophilic anaerobic sequenced batch reactor was applied to treat synthetic glucose wastewater in order to investigate the characteristics of soluble microbial product （SMP） in the effluent of thermophilic anaerobic digestion process. The dissolved organic matter （DOM） in the effluent was fractionated using size exclusion chromatography and characterized by dissolved organic carbon content （DOC）, UV254 absorbance and fluorescence excitation-emission matrix. The SMP accounted for 90.8% of the DOM in the effluent. The distribution ratios of SMP in high-molecular weight （MW） （10k-100kDa）, medium-MW （1k-10kDa） and low-MW （1kDa） DOM fractions were 46.8%, 45.4%, 7.8%, respectively. The DOM fraction with high MW showed higher ultraviolet absorptivity than that with low and medium MW. The SMP was characterized by relatively high content of tyrosine-like substances and low content of fulvic acid-like and humic acid-like substances. Low-MW fraction mainly contained tyrosine-like aromatic substances, whereas all fulvic acid-like and humic acid-like substances distributed in the medium-MW fraction, and tryptophan-like protein and soluble microbial by-product-like substance extensively distributed in different MW range fractions. There was no significant difference between the fluorescence profiles of high and medium MW fractions, except a little change in the structures of tryptophan-like aromatic protein and soluble microbial by-product-like substances.