论文部分内容阅读
减少养分的损失是控制面源污染最有效和经济的方法。通过淋溶试验评价带负电荷的阴离子淀粉对土壤养分离子的吸附作用,寻找对土壤养分离子吸附效果好的淀粉种类。试验1设置5个处理:去离子水、硝酸钾,以及硝酸钾分别与黄原酸酯淀粉、磷酸酯淀粉和羧甲基淀粉等3种不同淀粉混合;试验2设置去离子水、黄原酸酯淀粉、黄原酸酯淀粉和氯化铵混合、氯化铵等4个处理。阴离子淀粉取代度是决定它们对阳离子吸附强度的主要因子,供试的3种阴离子淀粉对土壤中的阳离子吸附作用高低顺序:羧甲基淀粉>磷酸酯淀粉>黄原酸酯淀粉。以黄原酸酯淀粉为载体,用氯化铵溶液处理结果表明:黄原酸酯淀粉对土壤中的钠、钾、镁和钙等4种阳离子均有显著的吸附作用(P<0.05);而用硝酸钾溶液处理时,黄原酸酯淀粉对土壤中的钠离子、铵离子和钾离子吸附效果较好,而对钙、镁等2种离子的吸附效果不明显,说明淀粉对阳离子的吸附效果与加入的营养液也有很大的关系。阴离子淀粉对阴离子养分没有吸附作用。试验推测,具有较高取代度的黄原酸酯淀粉可作为理想的吸附剂,没有潜在风险;在降水量较小的地区,较高取代度的磷酸酯淀粉也可以作为理想的吸附剂,因为没有铵离子淋失的风险。
Reducing the loss of nutrients is the most effective and economical way to control non-point source pollution. The leaching test was used to evaluate the adsorption of negatively charged anionic starch on soil nutrient ions and to find the starch species that has good ion adsorption on soil nutrients. Experiment 1 set five treatments: deionized water, potassium nitrate, and potassium nitrate were mixed with xanthogenate starch, phosphate starch and carboxymethyl starch and other three kinds of different starch mixed; Test 2 set deionized water, xanthogen acid Ester starch, xanthogenate starch and ammonium chloride, ammonium chloride treatment. The degree of substitution of anionic starch is the main factor that determines their adsorption strength to cation. The order of cationic adsorption of the three kinds of anionic starch to soil is as follows: carboxymethyl starch> phosphate starch> xanthogenate starch. The results showed that xanthogen starch had significant adsorption on four kinds of cations such as sodium, potassium, magnesium and calcium in soil (P <0.05) with xanthate as carrier. When treated with potassium nitrate solution, the xanthogen starch adsorbed sodium, ammonium and potassium in the soil better, while the adsorption of two ions such as calcium and magnesium was insignificant, indicating that the effect of starch on the cation Adsorption effect and join the nutrient solution also has a great relationship. Anionic starch has no adsorption on anionic nutrients. It has been postulated that xanthogenated starch with a higher degree of substitution can serve as an ideal adsorbent without potential risks; higher degrees of substitution of phosphate starch can also be ideal adsorbents in areas where the precipitation is relatively small There is no risk of ammonium leaching.