摘要
为提高剩余污泥的磷释放与回收效果,采用超声强化EDTA-厌氧处理后的剩余污泥释磷,并以鸟粪石(MAP)结晶法回收上清液中的磷,探究超声对磷释放的影响,同时确定了最佳超声工作参数,采用响应曲面法构建MAP法磷回收的二次多项式模型并验证了模型的适用性。结果表明,超声可以强化污泥中磷的释放,最佳超声工作参数如下:声能密度为1.0 W/m L、超声时间为40 min,在最佳工作参数下可向液相释放60%的TP,TP、PO34--P浓度分别达到未超声处理的1.6倍和1.4倍;经超声后污泥上清液中TP增加量与MLSS、MLVSS减少量呈正相关关系,每溶解1 mg的MLSS向上清液中释放0.0101 mg的TP;磷回收的最优工艺条件:nMg/nP=2、pH值=9、搅拌时间为21 min,此时磷回收率为89.29%,回收的晶体产物主要成分是磷酸铵镁,其纯度为77.56%,且相比未超声,该条件下的回收量提高了30%。
In order to improve phosphorus release and recovery from sludge,ultrasound was applied to enhance phosphorous release from sludge treated by EDTA and anaerobic digestion,and then the phosphate in the supernatant was recovered by MgNH4 PO4·6 H2 O(MAP)crystallization.Effect of ultrasound on phosphorus release was investigated,and the optimal ultrasonic operational parameters were determined.A quadratic polynomial model of phosphorus recovery by MAP method was constructed by response surface method(RSM)and its applicability was verified.The application of ultrasound could significantly strengthen phosphorus release of anaerobic digested sludge.The optimal ultrasonic operational parameters were as follows:sound energy density of 1.0 W/m L and ultrasonic time of 40 min.Under the optimal parameters,60%of TP could be released to the liquid phase,and TP and PO34--P concentrations were 1.6 times and 1.4 times higher than those obtained by non-ultrasonic treatment.The increase of TP in supernatant after ultrasound was positively correlated with the decrease of MLSS and MLVSS,and 1 mg MLSS released 0.0101 mg TP into the liquid.The optimal conditions of phosphorus recovery were as follows:nMg/nP=2,pH value of 9 and stirring time of 21 min,and the phosphorus recovery rate was 89.29%.The main component of the recovered crystals was magnesium ammonium phosphate with a purity of 77.56%,and the yield of obtained crystals increased by 30%compared to that without ultrasound.
作者
胡德秀
张聪
张艳
HU De-xiu;ZHANG Cong;ZHANG Yan(State Key Laboratory of Eco-hydraulics in Northwest Arid Region,Xi’an University of Technology,Xi’an 710048,China)
出处
《中国给水排水》
CAS
CSCD
北大核心
2020年第15期65-72,共8页
China Water & Wastewater
基金
省部共建西北旱区生态水利国家重点实验室基金资助项目(2016ZZKT-8)。
关键词
剩余污泥
超声
鸟粪石(MAP)
磷释放
磷回收
excess sludge
ultrasound
magnesium ammonium phosphate(MAP)
phosphorus release
phosphorus recovery
