底泥和藻体对太湖湖泛的诱发及水体致黑物的供应潜力

J．LakeSci．(湖泊科学)，2015，27(4):575-582DOI10．18307/2015．04032015byJournalofLakeSciences底泥和藻体对太湖湖泛的诱发及水体致黑物的供应潜力*蔡萍1，吴雨琛1，刘新1，尹洪斌2＊＊(1:南京林业大学，南京210037)(2:中国科学院南京地理与湖泊研究所，南京210008)摘要:为确定底泥和藻体在太湖湖泛形成过程中对致黑物形成的贡献，采用室内模拟系统，研究底泥、蓝藻以及底泥+蓝藻3种处理，模拟湖水在不同厌氧程度下湖泛特征参数(黑度、铁及硫形态)的变化，分析不同处理以及受不同聚藻程度影响区(八房港、焦山)底泥对湖泛的诱发作用及致黑物供给潜力．结果表明，各处理组诱发太湖湖泛发生的难易顺序为:底泥+蓝藻处理组＞底泥处理组＞蓝藻处理组．底泥+蓝藻处理组中Fe2+浓度为蓝藻处理组的11～94倍，其平均浓度为后者的33倍，而底泥+蓝藻处理组中还原性硫浓度为其他处理组的2～56倍．研究还发现，聚藻区底泥较非聚藻区更易发生湖泛，这是由于聚藻区底泥富集了更高浓度的铁、硫等还原性物质，但厌氧处理与非厌氧处理在诱发湖泛发生的风险差异不明显．以上结果证实，厌氧环境下低价铁硫供应潜力的差异是决定湖泛发生的主要物质来源，加强对聚藻区底泥及蓝藻的控制是有效防控太湖湖泛发生的主要措施之一．关键词:湖泛;诱发;硫化亚铁;底泥;藻体;太湖ThecontributionofsedimentandalgaltotheformationofblackbloomandtheirpotentialtosupplytheblacksubstanceinwatersinLakeTaihuCAIPing1，WUYuchen1，LIUXin1＆YINHongbin2(1:NanjingForestryUniversity，Nanjing210037，P．Ｒ．China)(2:NanjingInstituteofGeographyandLimnology，ChineseAcademyofSciences，Nanjing210008，P．Ｒ．China)Abstract:Alaboratorysimulationsystemwasestablishedtoidentifythecontributionofalgalandsediment(speciallythetreat-mentsincludingalgal，algal+sedimentandsedimentonly)totheformationofblackbloominLakeTaihu．Blackness，ironandsulfurfractionswereanalyzedundervariedanaerobicconditionandthecontributionandpotentialofsedimentfromdifferentalgal-loadedareatoinducetheblackbloomwerededuced．Theresultsindicatedthetreatmentshaveadescendingorderinthecontribu-tiontotheformationofblackbloomas:algaltreatment＜sedimenttreatment＜algal+sedimenttreatment．Ferrousironinthealgal+sedimenttreatmentwas11to94fold(average33fold)asthatofalgaltreatment．Theconcentrationofreducedsulfideinthealgal+sedimenttreatmentwas2to56foldasthatofothertreatments．Theresultsalsoindicatedthatsedimentinthealgal-load-edareahasgreaterpotentialtoinducetheblackbloomthansedimentinthenonalgal-loadedarea．Whereas，littledifferencewasobservedintheformationofblackbloombetweenanaerobicandnontreatment．AlltheresultsindicatedthatthepotentialtosupplythelowvalencestateofironandsulfideinanaerobicconditionhasadecisiveeffectontheformationofblackbloominLakeTaihu