生态环境学报
生態環境學報
생태배경학보
ECOLOGY AND ENVIRONMENT
2013年
5期
857-862
,共6页
许海波%赵道远%刘培亚%李玉姣%董长勋
許海波%趙道遠%劉培亞%李玉姣%董長勛
허해파%조도원%류배아%리옥교%동장훈
团聚体%镉%铬(Ⅵ)%吸附%动力学
糰聚體%鎘%鉻(Ⅵ)%吸附%動力學
단취체%력%락(Ⅵ)%흡부%동역학
aggregates%cadmium%chromium (Cr(Ⅵ)%adsorption%kinetic
利用低能量超声波分散、虹吸法沉降分离的方法分离不同粒径的水稻土团聚体颗粒,采用恒温振荡法研究不同浓度磷酸盐预处理的团聚体对Cd2+、Cr(Ⅵ)平衡吸附以及吸附动力学的影响。结果表明,砂粒级、粗粉砂级、粉砂级和粘粒级对P吸附量分别小于50、46、50和97 mg?kg-1,Cd2+吸附量低于未处理土样,P吸附量大于该数值,Cd2+吸附量高于未处理土样,团聚体吸附磷酸盐对Cd2+吸附量的影响,表现为低P吸附量抑制Cd2+的吸附,高P吸附量促进Cd2+的吸附,即随P吸附量增加Cd2+的吸附量呈波谷形变化;而团聚体吸附磷酸盐后对Cr(Ⅵ)的吸附则表现明显的抑制作用。磷酸盐预处理的团聚体对Cd2+、Cr(Ⅵ)吸附量大小顺序均为粘粒级>砂粒级>粗粉砂级>粉砂级,与有机质和游离氧化铁的含量顺序一致。团聚体对Cd2+的吸附过程分为快、慢两个阶段,快吸附阶段用一级动力学方程拟合最佳,而慢吸附时段用扩散方程和Elovich方程拟合最佳,表明吸附过程由不同的吸附因素控制。团聚体吸附磷酸盐后对Cd2+的吸附动力学常数增大。团聚体对Cr(Ⅵ)的吸附过程无明显快、慢阶段,对Cr(Ⅵ)吸附的整个过程用双常数速率方程和Elovich方程进行描述最佳,团聚体吸附磷酸盐后对Cr(Ⅵ)的吸附动力学常数减小。磷酸盐对土壤中重金属吸附的影响与金属离子类型以及磷吸附量有关,所以采用磷肥等含磷物质修复重金属污染土壤要注意金属离子的类型和磷肥的施用量。
利用低能量超聲波分散、虹吸法沉降分離的方法分離不同粒徑的水稻土糰聚體顆粒,採用恆溫振盪法研究不同濃度燐痠鹽預處理的糰聚體對Cd2+、Cr(Ⅵ)平衡吸附以及吸附動力學的影響。結果錶明,砂粒級、粗粉砂級、粉砂級和粘粒級對P吸附量分彆小于50、46、50和97 mg?kg-1,Cd2+吸附量低于未處理土樣,P吸附量大于該數值,Cd2+吸附量高于未處理土樣,糰聚體吸附燐痠鹽對Cd2+吸附量的影響,錶現為低P吸附量抑製Cd2+的吸附,高P吸附量促進Cd2+的吸附,即隨P吸附量增加Cd2+的吸附量呈波穀形變化;而糰聚體吸附燐痠鹽後對Cr(Ⅵ)的吸附則錶現明顯的抑製作用。燐痠鹽預處理的糰聚體對Cd2+、Cr(Ⅵ)吸附量大小順序均為粘粒級>砂粒級>粗粉砂級>粉砂級,與有機質和遊離氧化鐵的含量順序一緻。糰聚體對Cd2+的吸附過程分為快、慢兩箇階段,快吸附階段用一級動力學方程擬閤最佳,而慢吸附時段用擴散方程和Elovich方程擬閤最佳,錶明吸附過程由不同的吸附因素控製。糰聚體吸附燐痠鹽後對Cd2+的吸附動力學常數增大。糰聚體對Cr(Ⅵ)的吸附過程無明顯快、慢階段,對Cr(Ⅵ)吸附的整箇過程用雙常數速率方程和Elovich方程進行描述最佳,糰聚體吸附燐痠鹽後對Cr(Ⅵ)的吸附動力學常數減小。燐痠鹽對土壤中重金屬吸附的影響與金屬離子類型以及燐吸附量有關,所以採用燐肥等含燐物質脩複重金屬汙染土壤要註意金屬離子的類型和燐肥的施用量。
이용저능량초성파분산、홍흡법침강분리적방법분리불동립경적수도토단취체과립,채용항온진탕법연구불동농도린산염예처리적단취체대Cd2+、Cr(Ⅵ)평형흡부이급흡부동역학적영향。결과표명,사립급、조분사급、분사급화점립급대P흡부량분별소우50、46、50화97 mg?kg-1,Cd2+흡부량저우미처리토양,P흡부량대우해수치,Cd2+흡부량고우미처리토양,단취체흡부린산염대Cd2+흡부량적영향,표현위저P흡부량억제Cd2+적흡부,고P흡부량촉진Cd2+적흡부,즉수P흡부량증가Cd2+적흡부량정파곡형변화;이단취체흡부린산염후대Cr(Ⅵ)적흡부칙표현명현적억제작용。린산염예처리적단취체대Cd2+、Cr(Ⅵ)흡부량대소순서균위점립급>사립급>조분사급>분사급,여유궤질화유리양화철적함량순서일치。단취체대Cd2+적흡부과정분위쾌、만량개계단,쾌흡부계단용일급동역학방정의합최가,이만흡부시단용확산방정화Elovich방정의합최가,표명흡부과정유불동적흡부인소공제。단취체흡부린산염후대Cd2+적흡부동역학상수증대。단취체대Cr(Ⅵ)적흡부과정무명현쾌、만계단,대Cr(Ⅵ)흡부적정개과정용쌍상수속솔방정화Elovich방정진행묘술최가,단취체흡부린산염후대Cr(Ⅵ)적흡부동역학상수감소。린산염대토양중중금속흡부적영향여금속리자류형이급린흡부량유관,소이채용린비등함린물질수복중금속오염토양요주의금속리자적류형화린비적시용량。
The different particle size fractions of paddy soil were separated using the low-energy ultrasonic dispersion and siphon sedimentation methods, and the effects of different phosphate concentrations on the characteristics of the adsorption and the adsorption kinetics of cadmium and chromium4+ by aggregates in paddy soil were studied by the constant temperature oscillation method. The results show that the adsorption amount of Cd2+ is lower than that of the untreated soil when the adsorption capacities of phosphate by the sand, coarse silt, silt and clay are less than 50, 46, 50 and 97 mg·kg-1, respectively, and the adsorption amount of Cd2+ is more than that of the untreated soil when the adsorption amounts of phosphate are more than the above values, respectively, indicating that the low adsorption of phosphate inhibits the adsorption of Cd2+, while the high adsorption of phosphate favors the adsorption of Cd2+. With the increase of phosphate adsorption, the adsorption of Cd2+ changes in a trough shape variation. However, the aggregates inhibit the adsorption of Cr(Ⅵ)significantly after the adsorption of phosphate. The adsorption amounts of Cd2+ and Cr(Ⅵ) by the aggregates pretreated by phosphate are in the order: cosmid > sand > coarse silt > silt, which is the same as the order of the concentrations of organic matter and free iron oxide. The adsorption process of Cd2+ by the aggregates is divided into two stages, which are the fast period and the slow period. In the fast adsorption period, the adsorption is fitted best by first-order kinetic equation, while in the slow period, it is fitted best by the diffusion equation and the Elovich equation, suggesting that the adsorption process is controlled by the different adsorption factors, and the adsorption kinetic constant of Cd2+ increases when the aggregates adsorb phosphate. The adsorption process of Cr(Ⅵ) by the aggregates does not have the fast and slow periods, and the adsorption of Cr(Ⅵ) by the aggregates can be best described by the double constant rate equation and the Elovich equation, and the adsorption kinetic constant of Cr(Ⅵ) decreases after the aggregates adsorb phosphate. The effect of phosphate on the adsorption of heavy metals in the soil was related to the types of metal ions as well as the adsorption amount of phosphate. Therefore, the types of metal ions and application amount of phosphate fertilizer should be paid attention to during the restoration of the heavy metal contaminated soil using the phosphate fertilizer.