本文選題：土壤　切入點：粘粒　出處：《吉林農(nóng)業(yè)大學》2015年碩士論文

【摘要】：應(yīng)用平衡吸附試驗法,研究了不同Cd2+濃度、不同pH值環(huán)境、添加不同濃度外源干擾Fe3+、Al3+條件下,對黑土、粘粒及粘粒級復(fù)合體對重金屬鎘(Cd)的吸附解吸試驗.結(jié)果表明:(1)隨著重金屬Cd2+平衡濃度的增加,供試土壤對Cd2+的吸附量也伴隨增加,具體表現(xiàn)為粘粒級復(fù)合體原土粘粒。吸附量的大小與供試土樣的比表面積,單位質(zhì)量內(nèi)所含的有機質(zhì),粘土礦物及金屬氧化物含量成正相關(guān),有利于重金屬鎘的吸附。(2)通過對數(shù)據(jù)進行Langmuir方程和Freundlich方程擬合,原土、粘粒級復(fù)合體、粘粒對Cd2+的吸附等溫線可通過Freundlich方程進行很好地描述而Langmuir方程則不適宜對Cd2+吸附等溫線的描述。(3)加入外源干擾離子Fe3+后,原土、土壤粘粒、粘粒級復(fù)合體對Cd2+的吸附量隨著Fe3+濃度的升高而降低,吸附量順序的具體表現(xiàn)為原土粘粒級復(fù)合體粘粒。(4)加入外源干擾離子Al3+后,原土、土壤粘粒、粘粒級復(fù)合體對Cd2+的吸附量隨Al3+濃度的增高亦有降低趨勢。吸附量順序的具體表現(xiàn)為粘粒級復(fù)合體粘粒原土。(5)在pH為9時,原土、粘粒、粘粒級復(fù)合體的吸附量達到最大值,具體表現(xiàn)為:原土粘粒級復(fù)合體粘粒。在解吸試驗中,原土、粘粒、粘粒級復(fù)合體均會隨著pH的升高而降低,具體表現(xiàn)為:粘粒級復(fù)合體粘粒原土。并且三種供試土壤均在pH為5時達到最大解吸量。pH可通過影響重金屬Cd2+的水解、Cd2+與H+的交換作用、供試土壤的吸附表面類型及吸附表面電荷,吸附解吸競爭體系中鎘分配系數(shù)等方面,對重金屬鎘離子的吸附產(chǎn)生影響。
[Abstract]:The equilibrium adsorption test was used to study the effects of different concentrations of Cd2 and pH on black soil under the condition of adding different concentrations of exogenous interference of Fe3 and Al3 to black soil. The adsorption and desorption of heavy metal CD ~ (2 +) by clay and clay grade complexes were studied. The results showed that the adsorption amount of Cd2 in the soil increased with the increase of Cd2 equilibrium concentration of heavy metal, and the adsorption of CD _ (2 +) on CD _ (2 +) was also increased with the increase of Cd2 equilibrium concentration. The adsorption amount is positively correlated with the specific surface area of the soil sample, the organic matter, clay mineral and metal oxide content in the sample per unit mass. The data were fitted by Langmuir equation and Freundlich equation. The adsorption isotherms of Cd2 on clay particles can be described by Freundlich equation, but Langmuir equation is not suitable for describing Cd2 adsorption isotherms. The adsorption amount of Cd2 on clay complex decreased with the increase of Fe3 concentration, and the order of adsorption capacity was that the original soil and soil clay particles were added with exogenous interference ion Al3, and the order of adsorption capacity was that the original soil and soil clay particles were added with the addition of external interfering ion Al3. The amount of Cd2 adsorbed by clay grain-grade complex also decreased with the increase of Al3 concentration. The order of adsorption capacity was that the adsorption capacity of clay grain-grade complex reached the maximum at pH 9, and the adsorption capacity of clay, clay and clay grade complex reached the maximum. In the desorption test, the clay, clay and clay grade complexes will decrease with the increase of pH. The results were as follows: clay grade complex clay soil, and the maximum desorption amount of the three soils was reached at pH 5. The pH could affect the exchange of CD 2 and H by the hydrolysis of heavy metal Cd2. The adsorption surface type and surface charge of the soil and the CD partition coefficient in the desorption competition system have an effect on the adsorption of heavy metal cadmium ion.
【學位授予單位】：吉林農(nóng)業(yè)大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：X53

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本文編號：1672521