【摘要】：采用OECD guideline 106批平衡吸附法研究環(huán)丙沙星在堿土中的等溫吸附特性、吸附動(dòng)力學(xué)、吸附熱力學(xué)以及pH值和Ca~(2+)濃度對(duì)其吸附的影響。結(jié)果表明環(huán)丙沙星在鹽堿土中的吸附較好地符合Freundlich方程(擬合系數(shù)R~2=0.981),不同初始濃度的環(huán)丙沙星在鹽堿土中的吸附過程符合準(zhǔn)二級(jí)動(dòng)力學(xué)方程,吸附常數(shù)為1.17×10~(-3)~5.67×10~(-3)kg·min~(-1)·m L~(-1)。吸附過程可分為快速吸附和慢速平衡兩個(gè)階段,初始濃度分別為80、100、120 mg·L~(-1)的環(huán)丙沙星吸附平衡時(shí)間為24 h,平衡吸附比例分別為89.9%、92.2%、92.7%。吸附熱力學(xué)參數(shù)ΔG0且ΔH=-3.58 5 k J·mol~(-1),表明環(huán)丙沙星在鹽堿土上的吸附為自發(fā)的放熱反應(yīng)。隨著溶液pH值的升高,鹽堿土對(duì)環(huán)丙沙星的吸附能力不斷減弱,當(dāng)pH9后吸附能力快速減少。以不同濃度CaCl_2作為背景液,環(huán)丙沙星在鹽堿土中的等溫吸附曲線用Freundlich方程擬合效果較好,lgKf值隨著CaCl_2背景溶液濃度的增加而減小,且環(huán)丙沙星初始濃度較小時(shí)其所受離子強(qiáng)度的影響相對(duì)較小。
[Abstract]:The adsorption characteristics, adsorption kinetics, adsorption thermodynamics, pH value and Ca~ (2+) concentration of ciprofloxacin in alkaline soil were studied by OECD guideline 106 batch equilibrium adsorption method. The adsorption process of ciprofloxacin in saline-alkali soil conforms to the quasi-second-order kinetic equation, and the adsorption constant is 1.17 (-3) ~ 5.67 (-3) kg (-1) (-1) (-1). The adsorption process can be divided into two stages: fast adsorption and slow equilibrium. The initial concentration of ciprofloxacin is 80,100,120 mg 65 The adsorption thermodynamic parameters G0 and H=-3.585 K J.mol~(-1) indicate that the adsorption of ciprofloxacin on saline-alkali soil is spontaneous exothermic reaction. With the increase of pH value of solution, the adsorption capacity of saline-alkali soil to ciprofloxacin decreases rapidly after pH 9. The isothermal adsorption curves of ciprofloxacin in saline-alkali soil were fitted well by Freundlich equation. The lgKf value decreased with the increase of CaCl_2 background solution concentration, and the influence of ionic strength on the isothermal adsorption curves of ciprofloxacin was relatively small when the initial concentration of ciprofloxacin was small.
【作者單位】： 吉林農(nóng)業(yè)大學(xué)資源與環(huán)境學(xué)院;吉林省商品糧基地土壤資源可持續(xù)利用重點(diǎn)實(shí)驗(yàn)室;國家供水水質(zhì)監(jiān)測網(wǎng)長春監(jiān)測站;
【基金】：吉林省科技廳重大科技攻關(guān)專項(xiàng)(20130204054SF0) 吉教科合字[2014]第467號(hào)
【分類號(hào)】：X53;S156.4
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本文編號(hào)：2175618