【摘要】：采用海藻酸鈉、磷酸二氫鈣和碳酸氫鈉成功合成了包埋磷酸鹽的海藻酸鈣小球。通過(guò)掃描電鏡、傅里葉變換紅外光譜、X射線(xiàn)衍射等分析表征了該小球的形貌與結(jié)構(gòu)。研究p H值和初始金屬離子濃度對(duì)鉛鎘去除率的影響,發(fā)現(xiàn)吸附鉛鎘的最佳p H值分別為4.0和5.5;鉛鎘的最適初始濃度分別為200 mg/L和25 mg/L,對(duì)應(yīng)的去除率分別達(dá)94.2%和80%。XRD和FTIR的分析結(jié)果證實(shí)了該小球?qū)︺U鎘的去除機(jī)理為:鉛鎘離子吸附到小球的表面,與小球的羧基發(fā)生反應(yīng),進(jìn)而與磷酸根反應(yīng)生成穩(wěn)定的磷酸鹽沉淀。鉛鎘的吸附符合Langmuir等溫線(xiàn)方程,擬合系數(shù)R2分別為0.9957和0.988。根據(jù)Langmuir等溫線(xiàn)方程計(jì)算得到鉛鎘的理論飽和吸附量分別為263.16mg/g和82.64 mg/g。研究結(jié)果表明該小球?qū)θ芤褐械你U鎘離子有良好的處理效果,同時(shí)由于生成穩(wěn)定的沉淀物,也能應(yīng)用于處理被鉛鎘污染的水稻土。
[Abstract]:Calcium alginate beads embedded in phosphate were successfully synthesized by using sodium alginate, calcium dihydrogen phosphate and sodium bicarbonate. The morphology and structure of the sphere were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. The effects of pH value and initial metal ion concentration on the removal efficiency of lead and cadmium were studied. The results showed that the optimum pH values of Pb and CD adsorption were 4.0 and 5.5 respectively. The optimum initial concentrations of lead and cadmium were 94.2% for 200 mg/L and 94.2% for 25 mg/L, respectively, and the results of 80%.XRD and FTIR showed that the removal mechanism of lead and cadmium ions was as follows: lead and cadmium ions adsorbed on the surface of the pellets. It reacts with the carboxyl group of the pellet and then reacts with the phosphate radical to form a stable phosphate precipitation. The adsorption of lead and cadmium conforms to the Langmuir isotherm equation, and the fitting coefficients R2 are 0.9957 and 0.988 respectively. According to the Langmuir isotherm equation, the theoretical saturated adsorption capacity of lead and cadmium is calculated to be 263.16mg/g and 82.64 mg/g., respectively. The results show that the pellet has a good effect on the treatment of lead and cadmium ions in the solution, and it can also be used in the treatment of paddy soil contaminated by lead and cadmium because of the formation of stable sediment.
【作者單位】： 中南大學(xué)冶金與環(huán)境學(xué)院;中南大學(xué)國(guó)家重金屬污染防治工程技術(shù)研究中心;
【基金】：Project(51504299)supported by the National Science Found for Young Scientists of China Project(2012GS430101)supported by the National Science and Technology Program for Public Wellbeing,China
【分類(lèi)號(hào)】：X703;TQ424
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本文編號(hào)：2328465