| Carbamazepine is a heterocyclic (iminodiacetic styrene) broad-spectrum antiepileptic drug, and has the role of anti-peripheral nerve pain, anti-manic-depressive, anti-diuretic and antiarrhythmic. Carbamazepine is widely used in neurology and psychiatry in human daily lives. Because of its significant efficacy, carbamazepine is often used as a drug for the treatment of epilepsy and neuropathic pain, and is classified as a first-line antiepileptic drug. This pharmaceutical has been widely detected in the environment, and thus its environmental behavior and risk assessment have attracted special research attention. At present, the domestic study of the pollution caused by carbamazepine is still very few, mostly focused on carbamazepine removal in sewage treatment. It is almost impossible to find sorption behavior related information. Now, in the domestic a small amount of research has been conducted only in the carbamazepine removal in sewage treatment. Research is almost in the soil environment. Literature is not difficult to see, the mechanism of the absorption of carbamazepine in the soil is almost not In China, adsorption mechanism, adsorption model, adsorption model parameters of carbamazepine in typical soil has almost not yet been determined. The soil is the largest of the Survey Office for the drugs in the environment, The impact of drug migration, retention and transformation in the soil environment, the main dominant factor is the adsorption of the drug in the soil, the adsorption of the drug in the soil also directly affects the biological activity of drugs, and has always been considered an important process for controlling drug environmental behavior. The study of the adsorption behavior of carbamazepine in the soil has important significance for realizing and understanding the retention, distribution, fate and transportation, bioavailability of carbamazepine and exploring the rules of transportation and transformation of carbamazepine in the soil environmental.In the present thesis, the structures, properties, resource and harm of carbamazepine have been gleaned, the adsorption and migration of carbamazepine in the soil has been reviewed. This article studied the adsorption behavior of carbamazepine in10different soils collected in Yunnan by batch equilibrium method, and investigated the adsorption rules of carbamazepine in10different soils collected in Yunnan, studied the adsorption kinetics characteristics and thermodynamic characteristics in different soil, experimental determined the adsorption kinetics and thermodynamics of the curve, through the calculation of the thermodynamic state function, analyzed the adsorption mechanism, analyzed the relationship between the physical and chemical properties of the tested soil and adsorption parameters,and cations and dissolved organic matter (DOM) influences or do not influence to the adsorption of carbamazepine on the soil, it provides a theoretical basis for the environmental and chemical behavior and migration and transformation of carbamazepine in the soil.The main findings are as follows:(1) The adsorption isotherms of CBZ in the soil were fitted by using the Freundlich, Langmuir and Polanyi-Manes model, Freundlich equation fitting was more in line with the adsorption isotherm of CBZ in the soil according to the adjusted coefficient of determination comparison, its adjustable coefficient of determination is almost0.98. KF value of CBZ changes from0.03to17.05.(2) Correlation analysis of the relationship between the adsorption coefficient Kd of CBZ in10kinds of soil and the physical and chemical properties of10kinds of soil. Found that the adsorption coefficient Kd values was a significant positive correlation with clay and soil organic matter content, and did not significantly related with the soil CEC, pH value, fines content and sand content, adsorption of CBZ in10kinds of soil primarily affected by the soil physical and chemical properties of soil organic matter and clay content.(3) To two kinds of the soil with different organic matter content for example,this paper studied the adsorption kinetics of CBZ in the soil, PFOM,PSOM and two-compartment first order kinetics model were fitted,by the fitting data results, two-compartment first order kinetics model is more in line with the adsorption kinetics model of CBZ in the soil, its adjustable coefficient of determination is almost more than0.99.(4) two-compartment first order kinetics model fitting results showed that the adsorption rate of speed of the adsorption unit is a difference of60-388times. Shows the differences in adsorption kinetics. Simple calculations on the data obtained after the fast adsorption chamber and the slow adsorption chamber on the adsorption of the total contribution. In the initial1h, adsorption of CBZ on the MengZi soil3and MengZi soil1based on adsorption-led fast and slow adsorption supplemented. To two soils in the initial1h, fast adsorption unit accounted for more than98%of the total soil adsorption.Follow-up to167h, the slow adsorption contribution dominated, slow adsorption of the total adsorption capacity is between76%to98%. Can be seen from the calculation, the speed of the two adsorption units, respectively, dominate in the initial period (1h) and follow-up period (follow-up to167h).(5) To two kinds of the soil with different organic matter content for example,studied the thermal dynamics of CBZ in the soil.Kd increased with increasing temperature, ΔH>0, this illustrated adsorption of CBZ in the soil is an endothermic process. By calculating, the heat of adsorption of CBZ on two kinds of soil is40.11and24.43kJ/mol, speculated that the main adsorption force is hydrogen bonding, the same time the existence of van der Waals forces, dipole moment of force and hydrophobic force together. Δ G<0, it illustrated that the adsorption is spontaneous. ΔS>0, this shows that the strength of the solvent molecules into the liquid is greater than the solute molecules into the strength of the solid phase in the adsorption system.(6) With the concentration of NaCl, CaCl2in the balanced solution increased, the increasing trend of the CBZ concentration in the three kinds of soil is essentially unchanged. This shows that cation had no effects for the adsorption of CBZ in the soil, the conclusion is consistent with previously obtained. The adsorption coefficient Kd values did not significantly related with the soil CEC.(7) With increasing DOM concentration in the equilibrium solution, the increasing trend of the CBZ concentration in the three kinds of soil did not change significantly. |
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