摘要近年来，环境污染日益严重，含重金属离子的工业废水对环境和人体健康带

Abstract <br>In recent years, increasingly serious environmental pollution, industrial waste water containing heavy metal ions in the environment and human health caused serious harm, currently one of the important tasks of environmental pollution is how to efficiently and cost-effectively remove heavy metal ions in wastewater and will not cause secondary pollution. Starch is a natural organic polymer flocculant, its low cost, widespread, and good biodegradability, non-toxic, it does not pollute the environment. So, starch flocculant best. Compared with native starch, modified starch particle shape is no difference, but some change in the size, some large modified starch, modified starch will form a network structure, it will produce many advantages, such as: low water solubility, flow low, high thermal stability, high viscosity, acid and the like. Paper by basic sodium chloride and sodium hypophosphite binding of a modified maize starch and chitosan, kaolin, modified starch flocculant to explore made of activated carbon, modified corn starch with ultrasonic assisted, and modified starch made with a certain concentration of the flocculant solution Cd2 + and adsorption experiments and made the corresponding evaluation. Experimental results show that, in a certain concentration range, modified starch flocculant hypophosphite starch - activated carbon adsorption optimal. Single factor tests results show that the amount of sodium hydroxide was added to 1.2 ml of administration, modified starch flocculant dosage is 60mg, the adsorption time was 40 minutes, Cd2 + concentration under suitable conditions 500μg / L isochronous modified starch higher adsorption capacity flocculant. Since the adsorption time is too short, the causes of the low concentration of modified starch flocculant adsorption incomplete, in the above conditions may be modified starch flocculant adsorption amount is maximized as much as possible. <br>Keywords: starch, flocculant, modified starch, Cd2 +, adsorption

Summary<br>In recent years, environmental pollution is becoming more and more serious, industrial wastewater containing heavy metal ions has brought serious harm to the environment and human health, one of the important tasks of the current treatment of environmental pollution is how to effectively and low-cost removal of heavy metal ions in wastewater and will not bring secondary pollution. Starch is an organic natural polymer flocculant, its low price, widespread, and biodegradable good, non-toxic, will not cause pollution to the environment. Therefore, starch do flocculants are most suitable. Compared with natural starch, the particle shape of modified starch is not different, but there are some changes in size, modified starch is somewhat large, modification will form a mesh structure in starch, will produce many advantages, such as: low water solubility, low mobility, high thermal stability, high viscosity, acid resistance and so on. In this paper, the modified starch of corn starch was modified by alkaline sodium chloride and sodium sub-phosphate, combined with the modified starch flocculation agent made from cladding, kaolin, activated carbon, and the modification of corn starch was used with ultrasonic ultrasound, and the modified starch flocculation agent was made to carry out adsorption experiments with a certain concentration of Cd2-plus solution, and made a corresponding evaluation. The experimental results show that in a certain concentration range, the modified starch flocculation agent sub-phosphate sodium starch-activated carbon has the best adsorption. The results of the single-factor test showed that the adsorption of modified starch flocculants was higher under suitable conditions such as 1.2 ml of sodium hydroxide, 60 mg of modified starch flocculation, 40 minutes of adsorption, and 500 ?g/L concentration of Cd2 plus. Due to the short adsorption time, low concentration and other reasons for the conversion of starch flocculant adsorption is not complete, and in the above conditions can modify the starch flocculant adsorption as far as possible to achieve the maximum.<br>Keywords: starch, flocculants, modified starch, Cd2 plus, adsorption

abstract<br>In recent years, environmental pollution has become increasingly serious. Industrial wastewater containing heavy metal ions has brought serious harm to the environment and human health. At present, one of the important tasks of environmental pollution control is how to effectively and cheaply remove the heavy metal ions in wastewater without secondary pollution. Starch is a kind of organic natural polymer flocculant, which has the advantages of low price, wide existence, good biodegradability, non toxicity and no pollution to the environment. Therefore, starch is the best flocculant. Compared with natural starch, the particle shape of modified starch has no difference, but the size has some changes, and the modified starch has some large size. The modified starch will form a network structure in the starch, which will produce many advantages, such as: low water solubility, low fluidity, high thermal stability, high viscosity, acid resistance, etc. In this paper, corn starch was modified by basic sodium chloride and sodium hypophosphite, and the modified starch flocculant made of chitosan, kaolin and activated carbon was studied. The modified starch flocculant was modified by ultrasonic wave, and the adsorption experiment was carried out with a certain concentration of Cd2 + solution, and the corresponding evaluation was made. The results showed that the modified starch flocculant sodium hypophosphite starch activated carbon had the best adsorption capacity in a certain concentration range. The results of single factor test showed that the adsorption capacity of modified starch flocculant was higher under the conditions of 1.2ml sodium hydroxide, 60mg modified starch flocculant, 40 minutes adsorption time and 500 μ g / L Cd2 + concentration. Due to the short adsorption time and low concentration, the adsorption of modified starch flocculant is not complete, and the adsorption capacity of modified starch flocculant can be maximized as much as possible under the above conditions.<br>Key words: starch, flocculant, modified starch, Cd2 +, adsorption<br>