当前重金属水污染的问题日益严峻，含重金属离子废水的处理受到越来越广泛的

At present, the problem of heavy metal water pollution is becoming more and more serious, and the treatment of wastewater containing heavy metal ions has received more and more attention. The flocculation method is one of the most economical and effective water treatment methods. The development of new flocculants with excellent performance, safety and environmental protection is a research hotspot in water treatment work. Starch is an organic natural polymer flocculant, its price is low, and its biodegradability is good, non-toxic. Therefore, modified starch is widely used in the treatment of heavy metals in wastewater. <br>In this paper, basic sodium chloride and sodium hypophosphite are mainly used as modifiers, chitosan, kaolin, activated carbon, etc. are used as coagulants, and ultrasonic starch is used to modify corn starch to prepare modified starch flocculants. The adsorption performance of Cd2 + solution was studied. Under the same conditions, the effect of changing the type of flocculant, the amount of sodium hydroxide added, the amount of modified starch flocculant added, the adsorption time and the concentration of Cd2 + on the adsorption performance of Cd2 + solution. <br>The results show that under the same adsorption conditions, sodium hypophosphite-activated carbon modified starch flocculant adsorbs Cd2 + solution relatively well. Sodium hypophosphite-activated carbon modified starch flocculant showed a tendency to increase first and then decrease with the increase of sodium hydroxide dosage during the adsorption process; when the flocculant dosage increased, the adsorption capacity increased first and then Gradually approaching equilibrium; when the adsorption amount increases with time, its adsorption increases first and then decreases; when the concentration of Cd2 + increases, its adsorption increases first and then decreases.

当前重金属水污染的问题日益严峻，含重金属离子废水的处理受到越来越广泛的关注。絮凝法是最经济有效的水处理方法之一，开发性能优良、安全环保的新型絮凝剂是水处理工作的研究热点。淀粉是有机天然高分子絮凝剂，其价格低廉，且生物降解性良好，无毒。因此改性淀粉被广泛应用于废水中重金属的处理。<br>本文主要选用碱性氯化钠和次亚磷酸钠为主改性剂，以壳聚糖、高岭土、活性炭等为助凝剂，并借用超声波辅助对玉米淀粉进行改性，制备改性淀粉絮凝剂对Cd2+溶液进行吸附性能的研究。在相同条件下改变絮凝剂种类、氢氧化钠投加量、改性淀粉絮凝剂投加量、吸附时间和Cd2+浓度对Cd2+溶液进行吸附性能的影响。<br>研究结果表明，在相同的吸附条件下，次亚磷酸钠-活性炭改性淀粉絮凝剂对Cd2+溶液的吸附相对较好。次亚磷酸钠-活性炭改性淀粉絮凝剂在吸附过程中随着氢氧化钠投加量的增加，吸附呈现先增后减的趋势；在絮凝剂投加量增加时，吸附量先增大后逐渐趋于平衡；在吸附量随着时间的增加时，其吸附先增大后减小；在Cd2+浓度增加时，其吸附先增大后减小。

At present, the problem of heavy metal pollution is becoming more and more serious, and the treatment of wastewater containing heavy metal ions has attracted more and more attention. Flocculation is one of the most economical and effective methods of water treatment. The development of New Flocculants with excellent performance, safety and environmental protection is the research hotspot of water treatment. Starch is an organic natural polymer flocculant, which is cheap, biodegradable and nontoxic. Therefore, modified starch is widely used in the treatment of heavy metals in wastewater.<br>In this paper, basic sodium chloride and sodium hypophosphite were used as modifiers, chitosan, kaolin and activated carbon were used as coagulants, and corn starch was modified by ultrasonic wave to prepare modified starch flocculant for the adsorption of Cd2 + solution. Under the same conditions, the effects of flocculant type, sodium hydroxide dosage, modified starch flocculant dosage, adsorption time and Cd2 + concentration on the adsorption performance of Cd2 + solution were changed.<br>The results showed that under the same adsorption conditions, the sodium hypophosphite activated carbon modified starch flocculant had a relatively good adsorption on the Cd2 + solution. During the adsorption process of sodium hypophosphite activated carbon modified starch flocculant, with the increase of sodium hydroxide dosage, the adsorption shows a trend of increasing first and then decreasing; when the dosage of flocculant increases, the adsorption first increases and then gradually tends to balance; when the adsorption amount increases with time, the adsorption first increases and then decreases; when the concentration of Cd2 + increases, the adsorption first increases and then decreases.<br>