生物炭强化苯酚厌氧降解产甲烷特性

中国环境科学2020,40(2)：631~639ChinaEnvironmentalScience生物炭强化苯酚厌氧降解产甲烷特性高新,王高骏,李倩*,陈荣(西安建筑科技大学环境与市政工程学院,陕西西安710055)摘要：通过批次实验探究生物炭对苯酚厌氧降解产甲烷过程的促进机制,并考察了300,500,700℃下制备的生物炭对苯酚甲烷化过程延滞期、最大产甲烷速率和微生物群落结构的影响.结果表明:生物炭的电子交换能力与苯酚甲烷化过程具有显著关系(R2=0.997).与对照组相比,投加15g/L的生物炭可将苯酚甲烷化的延滞期从15.0d缩短至1.1~3.2d,最大产甲烷速率由4.0mL/d提高到10.4~13.9mL/d.其中在热解温度500℃下制备的生物炭由于含有丰富的电化学活性类醌结构,对苯酚甲烷化过程促进效果最优.此外,生物炭投加促进了典型产电细菌Geobacter及产甲烷菌Methanosaeta的富集.进一步说明生物炭投加通过促进种间电子传递加速了苯酚甲烷化过程.关键词：生物炭；苯酚降解；甲烷化；直接种间电子传递中图分类号：X703文献标识码：A文章编号：1000-6923(2020)02-0631-09Characteristicsofenhancedanaerobicdegradationandmethanogenesisofphenolbybiocharaddition.GAOXin,WANGGao-jun,LIQian*,CHENRong(SchoolofEnvironmental&MunicipalEngineering,Xi’anUniversityofArchitectureandTechnology,Xi’an710055,China).ChinaEnvironmentalScience,2020,40(2)：631~639Abstract：Thepotentialmechanismsforanaerobicphenoldegradationandmethanogenesispromotionbybiocharadditionwereevaluatedbybatchexperiments,andtheeffectsofbiocharderivedat300,500and700onlagtime,maximummethaneproduction℃rateandmicrobialcommunitystructurewereelucidatedinthisstudy.TheresultsindicatedastronglinearrelationshipbetweentheelectronexchangecapacityofbiocharandRmax(R2=0.997).Furthermore,methanogeniclagtimewasnotablyshortenedfrom15.0daysto1.1~3.2days,andthemaximumCH4productionratewasincreasedfrom4.0mL/dto10.4~13.9mL/dbybiocharaddition(15g/L).Moreover,themethanogenesisofphenolwasoptimizedbyadditionofbiocharpreparedat500℃becauseofthemostabundanceofelectrochemicallyactivequinones.Inaddition,microbialcommunityanalysisshowedthattheelectroactiveGeobacterandMethanosaetamicrobialconsortiawereenrichedbybiocharaddition.Itwasfurtherdemonstratedthatbiocharadditionfueledthemethaneproductionrateofphenolbypromotinginterspecieselectrontransfer.Keywords：biochar；phenoldegradation；methanogenesis；interspecieselectrontransfer作为一种常见的工业原料,苯酚广泛存在于石化、印染、纺织、农业等工业废水中,其致癌、致畸、致突变特性引起人们广泛关注[1-2].目前,工业废水中苯酚的去除方法主要有物理法,化学法和生物法[3-4].其中,厌氧生物处理法作为一种低能耗,可持续的绿色技术,近年来受到广泛关注[5].在厌氧条件下,苯酚可经过羧化、脱烃、β氧化、产甲烷等微生物代谢过程被降解为CO2、H2O、CH4等无害的小分子物