钙型天然斜发沸石同步脱氮除磷特性

以钙型天然斜发沸石为试验材料进行废水同步脱氮除磷特性研究，考察反应时间，沸石投加量，pH，温度及废水中的有机物含量对斜发沸石同步去除氨氮和磷的影响. 结果表明:在沸石投加量为250 g/L，pH为7.0～9.0，温度为25 ℃，吸附时间为24 h的条件下，钙型天然斜发沸石对氨氮的去除率达到96%，对磷的去除率接近100%. pH对钙型天然斜发沸石除磷效果影响显著，但对氨氮去除效果影响不大. 当pH由3.0升至5.0时，磷的去除率由54%降低至43%，吸附作用是磷的主导去除机制；当pH由5.0升至8.0时，磷的去除率迅速升高，化学沉淀逐渐成为磷的主导去除机制；pH为8.0以上时，磷的去除率接近100%. 废水有机物对钙型天然斜发沸石去除磷的效果存在差异，其中柠檬酸的加入使磷的去除率降低16%，显著抑制了磷的去除；腐殖酸的加入仅使磷的去除率降低3%，影响甚小. 柠檬酸和腐殖酸的加入对氨氮的去除效果影响均较小(低于3%). 

Characteristics of Ca-Type Clinoptilolite for Simultaneous Removal of Nitrogen and Phosphorus from Wastewater

Taking Ca-type clinoptilolite as the experimental material, batch experiments were carried out to investigate the influence of reaction time, dosage of Ca-type clinoptilolite, pH, temperature andorganic compounds on simultaneous removal of nitrogen and phosphorus from wastewater. The experiments showed that under the conditions of clinoptilolite dosage 250 mg/L, pH 7.0-9.0, temperature 25 ℃ and adsorption duration 24 h,the removal efficiency of high-concentration ammonium nitrogen by clinoptilolite could reach 96%, and the removal efficiency of phosphate could be close to 100%. The effect of pH on phosphate removal efficiency was significant, while the pH influence on ammonium nitrogen removal efficiency was very low. If the pH increases from 3.0 to 5.0, the removal efficiency of phosphate decreases from 54% to 43%, when adsorptive action is found to be the dominant phosphate removal mechanism. If the pH increases from 5.0 to 8.0, the removal efficiency of phosphate will rise dramatically, as chemical precipitation gradually becomes the dominant phosphate removal mechanism. Above pH 8.0, the removal efficiency of phosphate will be nearly 100%. The effect of organic matter on phosphate removal efficiency of clinoptilolite varied from one to another. Citric acid apparently restrained phosphate removal, reducing the removal efficiency by 16%, while humic acid had lessinfluence, reducing phosphate removal efficiency by only 3%. For ammonium nitrogen removal, the effect of both citric acid and humic acid was quite small, being less than 3%.