生物炭覆盖对底泥污染物释放的影响  

Effects of Biochar Covering on the Release of Pollutants from Sediment

作　　者：李扬[1] 李锋民[1] 张修稳[1] 吴召富[1] 于辉[1] 

机构地区：[1]中国海洋大学环境科学与工程学院,海洋环境与生态教育部重点实验室,青岛266100

出　　处：《环境科学》2013年第8期3071-3078,共8页Environmental Science

基　　金：国家水体污染控制与治理重大科技专项(2012ZX07203004);教育部新世纪优秀人才支持计划项目(NCET-11-0468);青岛市科技发展计划项目(10-3-3-21-nsh)

摘　　要：为研究生物炭对底泥污染物释放的影响,将芦竹茎、芦苇茎、花生壳及玉米芯利用限氧升温炭化法烧制成生物炭(Biochar),在模拟反应器中覆盖在受污染底泥上,研究生物炭对上覆水NH4+-N、NO3--N、NO2--N、COD及PO34--P浓度的影响,并计算各指标累积释放量及释放速率;同时测定了生物炭可溶性NH4+-N和PO34--P的释放量.结果表明,未覆盖生物炭的对照组上覆水氨氮浓度在第25 d达到最大值4.27 mg·L-1,之后稳定在4.02 mg·L-1左右,而4种生物炭处理组在第25 d以后,氨氮浓度稳定在0.3 mg·L-1以下,其中芦苇处理组抑制效果最明显,氨氮累积释放量减少了85.61%;4种生物炭组COD累积释放量较未添加生物炭处理组减少了28.83%～30%;玉米芯生物炭处理组磷酸盐浓度高于对照组,芦竹及花生壳处理组对底泥磷的释放抑制效果较好.生物炭NH4+-N和PO34--P的释放量在前3 d最大,花生壳生物炭组氨氮释放量最大,为36.79mg·kg-1,玉米芯生物炭处理组磷酸盐释放量最大,为70.64 mg·kg-1.结果表明生物炭对底泥NH4+-N、COD及PO34--P的释放有削减作用,具有应用到污染水体底泥修复的潜力.In order to study the effects of biochar on the release of pollutants from sediment,Arundo donax,Phragmites australis,Arachis hypogaea and Zea mays were pyrolyzed into biochar.Biochar was used to cover the contaminated sediment in the simulated reactors.Concentrations of NH＋4-N,NO-3-N,NO-2-N,COD and PO3-4-P were continuously monitored,and the cumulative release amount and release rate were calculated.Besides that,the release amount of water-soluble NH＋4-N and PO3-4-P from biochars were determined.In the blank control group,which was not covered with any kinds of biochar,the ammonia-nitrogen concentration of the overlying water reached a maximum value of 4.27 mg·L-1 on the twenty-fifth day,and then stabilized at about 4.02 mg·L-1.Ammonia-nitrogen concentrations of the treatment groups with the four kinds of biochar all maintained below 0.3 mg·L-1 after 25 days.Particularly,the Phragmites australis treatment group showed the best ability to inhibit ammonia-nitrogen release,and the cumulative release amount of ammonia-nitrogen was reduced by 85.61%.The cumulative release amount of COD was reduced by 28.83% to 30%.Phosphate concentration of the Zea mays group was higher than that of the blank group.On the contrary,Arundo donax and Phragmites australis groups showed a great potential in the inhibition of phosphate release.Biochar released the majority of NH＋4-N and PO3-4-P in the first 3 days.The release amount of NH＋4-N from Arachis hypogaea group was larger than those of the other three groups,reaching 36.79 mg·kg-1.Similarly,Zea mays group had the largest release of PO3-4-P,which was 70.64 mg·kg-1.All suggest that biochar is a potential in-situ capping material to reduce the release of NH＋4-N,COD and PO3-4-P in polluted sediments,and has the ability of applying to the remediation of sediment in the polluted water.

关 键 词：生物炭 覆盖 底泥 污染物释放 累积释放量 释放速率 

分 类 号：X52[环境科学与工程—环境工程]