五氯酚在稻田中的降解动态及生物有效性  

Degradation kinetics and bioavailability of pentachlorophenol in paddy soil-rice plant ecosystem

作　　者：王诗生[1] 李德鹏[1] 

机构地区：[1]安徽工业大学建筑工程学院,马鞍山243002

出　　处：《生态学报》2011年第6期1749-1755,共7页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目(40621001);安徽省高校自然科学研究重点项目(KJ2010A049)

摘　　要：利用江西鹰潭红壤生态实验站的长期施肥定位试验,采用田间微域研究了五氯酚(pentachlorophenol,PCP)在红壤性水稻田生态系统中的降解动态和稻谷的富集特征。四种长期施肥处理包括:未施肥(对照,CK)、施尿素(N)、施有机肥(OM)以及施有机肥+尿素(N+OM)。结果表明,长期施用OM或N+OM能显著增加土壤微生物活性。PCP在土壤-水稻生态系统中的降解遵循一级动力学方程,在CK、N、OM和N+OM 4种处理土壤中降解半衰期分别为27.7、35.2、24.8、22.4 d。表明长期施用OM或N+OM能加速PCP降解,而长期施用N抑制PCP降解。土壤中PCP(初始浓度85 mg/kg)显著减少水稻茎和稻谷生物量,但是对水稻根生物量并没有显著影响。在4种处理中水稻稻谷中PCP含量并没有显著差异,且稻谷的生物富集系数均小于0.01。PCP虽然在土壤-水稻生态系统中的降解半衰期较短,但是仍可以在水稻稻谷中有一定的生物富集,潜在的食品安全风险依然存在。The in situ microcosm experiment was set up in the four long-term fertilization field experiments,the degradation kinetics and bioaccumulation characteristics of pentachlorophenol（PCP） with initial concentration of 85 mg/kg in paddy soil-rice plant ecosystem were investigated.The long-term fertilization field experiment employed was in the Experimental Station of Red Soil,the Chinese Academy of Sciences,located in Yingtan,Jiangxi Province,China.The four long-term fertilization treatments included（1） no fertilizer（the control,CK）,（2） application of urea（N）,（3） application of organic fertilizer（OM）,and（4） mixed organic fertilizer and urea（N＋OM）,and no addition of PCP as control was also set up for any treatment.The results showed that carbon dioxide release in OM and N＋OM was both higher than that in CK,but no significant difference was observed between CK and N,indicating that long-term fertilization of organic fertilizer or mixed organic fertilizer and urea increased microbial activities in paddy soil,but no effect on microbial activity was showed under long-term fertilization of urea.PCP residue in paddy soil gradually decreased with time increasing in four treatments.After the rice plant was harvested,the final PCP residue in N＋OM was the least,was 8.7 mg/kg,and the highest PCP residue was in N,was 30.9 mg/kg.It could be found that PCP degradation followed one-order kinetics equation in four treatments,and the fitting degrees were 97.7%,78.8%,89.5%,91.7% for CK,N,OM and N＋OM,respectively.According to one-order kinetics equation,the half-lives calculated of PCP degradation were 27.7,35.2,24.8 and 22.4 days for CK,N,OM and N＋OM,respectively.The results observed indicated that long-term fertilization of organic fertilizer or mixed organic fertilizer and urea accelerated PCP degradation,but long-term fertilization of urea inhibited PCP degradation.As for no addition of PCP in four treatments,the air-dried shoot and grain biomass of rice plant in N＋OM and OM was signif

关 键 词：五氯酚 降解 长期施肥 土壤-水稻生态系统 生物有效性 

分 类 号：X592[环境科学与工程—环境工程]