污泥喷雾热干化特性

Performance of sprayed sludge drying

污泥喷雾干化是将剩余污泥通过雾化嘴喷雾后形成雾滴,并与太阳能产生的高温气体逆向接触以达到干化的目的。本文研究了污泥脱水性能,以及污泥溶出和冷凝水中的磷酸盐、氨氮、阴阳离子及重金属的变化。结果表明：随着喷入量减小,污泥的含水率逐渐减小,在喷入量为12L/h时,干化后污泥的含水率降低到25.9%;干化后污泥溶出的磷酸盐和氨氮随着喷入量的减少呈现出升高的趋势,在污泥含水率小于60%时,磷酸盐与氨氮的浓度分别分布在59.4~61.7mg/L与156.4~165.3 mg/L;随着喷入量增加,冷凝水中磷酸盐浓度基本不变,氨氮呈下降的趋势;干化后污泥溶出的阴阳离子的变化趋势相同,且随着含水率的升高,呈现增大趋势;冷凝水中的阴阳离子呈现先上升后下降的趋势;干化后污泥中的重金属除镉之外其余略有增加。

Drying of sludge spray is a process of sludge in countercurrent contact with heat gas produced by solar energy after waste sludge is sprayed by atomization nozzle. This study investigated the drying performance and the changes of phosphate,ammonia nitrogen,zwitterion and heavy mental both in the condensed water and the dry sludge. Results showed that the percentage of moisture reduced gradually when sludge spray decreased. When the flow of sludge was at 12L/h,the percentage of moisture reduced to 25.9%. The concentration of phosphate and ammonia nitrogen increased with of sludge spray reduced. Furthermore,when the moisture was less than 60%,the concentration of phosphate varied between 59.4—61.7mg/L while ammonia nitrogen varied between 156.4—165.3mg/L. When more sludge was sprayed,the concentration of phosphate was stable and ammonia nitrogen decreased in condensation water. Both the concentrations of dissolved anion and cation in dewatered sludge increased when the percentage of moisture increased. The heavy metals in sludge increased slightly after dewatered.