几种人工湿地基质净化磷素的机理_袁东海

中国环境科学2004,24(5)：614~617ChinaEnvironmentalScience几种人工湿地基质净化磷素的机理袁东海1,景丽洁2,张孟群3,高士祥1,尹大强1,王连生1*(1.南京大学污染控制与资源化国家重点实验室,江苏南京210093；2.吉林化工学院环境科学系,吉林吉林132022；3.南京大学现代分析中心,江苏南京210093)摘要：研究了砂子、沸石、蛭石、黄褐土、下蜀黄土、粉煤灰和矿渣7种人工湿地基质材料净化污水磷素的机理,并初步评价了其作为人工湿地基质可能导致的磷素二次污染的风险.结果表明,矿渣、粉煤灰有很好的磷素去除效果,蛭石、黄褐土和下蜀黄土次之,沸石和砂子的去除效果较差.上述人工湿地基质净化磷素的机理主要为化学机理,表现为基质全钙、氧化钙、水溶性钙的含量越高,其固定形成的磷酸钙盐越多,在pH值较高的情况下,主要形成难溶性的磷酸八钙和磷酸十钙,有利于磷素的净化;基质中游离氧化铁、铝和胶体氧化铁、铝含量越高,其固定形成的磷酸铁盐和磷酸铝盐数量越多,基质净化磷素的能力越强.除砂子外,上述基质磷素饱和吸附后,磷素释放比例很低.加强人工湿地基质管理,其基质吸附的磷素一般不会对水体环境造成二次污染.关键词：人工湿地；基质；磷素；净化；机理中图分类号：X505,X703文献标识码：A文章编号：1000-6923(2004)05-0614-04Mechanismofphosphoruspurificationinsomekindsofsubstratesconstructedwetlandsystems.YUANDong-hai1,JINGLi-jie2,ZHANGMeng-qun3,GAOShi-xiang1,YINDa-qiang1,WANGLian-sheng1(1.StatekeyLaboratoryofPollutionControlandResourceReuses,NanjingUniversity,Nanjing210093,China；2.DepartmentoftheEnvironmentalScience,JilinInstituteofChemicalTechnology,Jilin132022,China；3.ModernAnalysisCenter,NanjingUniversity,Nanjing210093,China).ChinaEnvironmentalScience,2004,24(5)：614~617Abstract：Themechanismofsewagephosphoruspurificationby7kindsofsubstratematerials(sand,zeolite,vermiculiteyellow-cinnamonsoil,Xiashuloess,flyashandflag)inconstructedwetlandwasstudied.Flagandflyashhadverygoodremovaleffectofphosphorus,followedbyvermiculite,yellow-cinnamonsoilandxiashuloess,thezeoliteandsandhadthelesseffect.Themechanismasmentionedabovewasmainlychemicalmechanism,sothemorethecontentoftotal,oxidizedandwatersolubleCa,themorethesolidifiedcalciumphosphate.UndertheconditionofhigherpH,thesolidifiedcalciumphosphatewasmainlythephosphatesofoctoandtencalciumhardtodissolve,sofavorabletophosphoruspurification.ThemorecontentsoffreeoxidesofFe,Al,aswellasofcolloidoxidesofFe,Alinsubstrate,themoreamountsofsolidificationphosphatesofFe,Al;thephosphoruspurificationcapacityofthesubstratewasmorestrange.Theratioofdesorptionandsaturatedadsorptionofphosphorusasmentionedabovewasverylowexceptsandsubstrate.Strengtheningthesubstratemanagementinconstructedwet