【摘要】 以黄土钙质结核作为吸附剂,以重金属离子(Cu²⁺,Zn²⁺,Cd²⁺和Pb²⁺)作为吸附质,通过单一重金属吸附试验,研究不同粒径、吸附时间、pH、吸附剂用量、重金属初始浓度和温度等因素对钙质结核吸附重金属离子的影响,并确定钙质结核吸附重金属离子的最优条件。结果表明:随粒径增大,Cu²⁺,Zn²⁺和Pb²⁺的吸附率逐渐下降,但对Cd²⁺无明显影响;随吸附时间、吸附剂用量和温度的增加,Cu²⁺,Zn²⁺,Cd²⁺和Pb²⁺的吸附率逐渐升高;随重金属离子初始浓度的增加,Cu²⁺,Zn²⁺和Cd²⁺的吸附率逐渐下降,而Pb²⁺的吸附率则呈先增加后减少的趋势;随pH增大,Cd²⁺的吸附率先陡然增加后缓慢增加,而Cu²⁺,Zn²⁺和Pb²⁺的吸附率先增加后减少。钙质结核对4种重金属离子的吸附能力呈Pb²⁺>Zn²⁺>Cu²⁺>Cd²⁺的顺序;在粒径为0.25 mm、吸附时间为120 min、用量为0.6 g时,钙质结核对Pb²⁺,Zn²⁺、Cu²⁺和Cd²⁺能达到较好的吸附,吸附率分别能达到其最大吸附率的83.33%,77.78%,73.81%和81.93%。钙质结核对Pb²⁺,Zn²⁺、Cu²⁺和Cd²⁺的最优吸附pH分别为7,6,5,8,最优温度为50℃。更多还原

【Abstract】 Calcareous concretion was used as adsorbent and heavy metal ions(Cu²⁺, Zn²⁺, Cd²⁺ and Pb²⁺) were used as adsorbates. Different particle size, adsorption time, pH, adsorbent dosage and initial concentration of heavy metals were studied by single heavy metal adsorption test. The influence of temperature and other factors on the adsorption of heavy metal ions by calcareous nodules was investigated, and the optimal conditions for the adsorption of heavy metal ions by calcareous concretion were determined. The results show that the adsorption rates of Cu²⁺, Zn²⁺ and Pb²⁺ decrease gradually with the increase of particle size, but have no obvious effect on Cd²⁺; with the increase of adsorption time, adsorbent dosage and temperature, the adsorption rates of Cu²⁺, Zn²⁺, Cd²⁺ and Pb²⁺ gradually increase; the adsorption rates of Cu²⁺, Zn²⁺ and Cd²⁺ decreased gradually with the increase of the initial concentrations of heavy metal ions, while the adsorption rate of Pb²⁺ increases first and then decreases; with the increase of pH, the adsorption rate of Cd²⁺ increases first and then increases slowly; the adsorption rates of Cu²⁺, Zn²⁺ and Pb²⁺ increase first and then decrease; the adsorption capacity of calcareous concretion to four heavy metal ions decrease in the order: Pb²⁺>Zn²⁺>Cu²⁺>Cd²⁺; when the particle size is 0.25 mm, the adsorption time is 120 min and the dosage is 0.6 g, the amounts of Pb²⁺, Zn²⁺, Cu²⁺; and Cd²⁺ adsorbed by the calcareous concretion can achieve the higher level, and the adsorption rates can reach 83.33%, 77.78%, 73.81% and 81.93% of their maximum adsorption rates, respectively. The optimal pH scales for calcareous concretion to adsorb Pb²⁺, Zn²⁺, Cu²⁺ and Cd²⁺ are 7, 6, 5 and 8, respectively, and the optimal temperature is 50℃.更多还原