剩余污泥臭氧化过程中磷的释放及形态转化

以剩余污泥臭氧化过程中含磷物质的形态分布及变化规律为研究核心,分析了不同臭氧投加量下污泥样品中液相和固相中磷的形态,并探讨了不同磷形态与臭氧相关的释放性能.结果表明,臭氧投加量为0.15 g·g~(-1)时,液相总磷(TP_L)含量为38.26 mg·L~(-1),比氧化前污泥混合液中TP_L含量增加了29倍,因此,可将0.15 g·g~(-1)作为实际释磷工艺最佳臭氧投加量.臭氧氧化过程中污泥固相中各形态磷含量及其所占固相总磷(TP_S)比例的变化趋势基本相同.臭氧可提高污泥中磷潜在的生物可利用性,臭氧投加量为0.15 g·g~(-1)时,生物有效磷含量达20.74 mg·g~(-1),在TP_S中所占比例由原始污泥中的73.60%提高至86.27%.TP_L含量的增加主要来自污泥臭氧氧化过程中污泥解絮和溶胞,每溶解1 g MLSS向液相中释放TP_L的量为0.0324 g.

Release and speciation of phosphorus during process of sludge ozone reduction

The mechanism of the sludge reduction through ozonation was systematically investigated using the excessive sludge obtained from municipal sewage treatment plants. The phosphorus fractions in liquid and solid phase were clarified and the release performance of different phosphorus fractions in solid related to ozone was also explored. The results indicate that the total phosphorus in liquid (TP_L) was 38.26 mg·L^-1 when the ozone dosage was 0.15 g·g^-1, which is 29 times more than that before oxidation. The forms of phosphorus content and its proportion in total phosphorus (TP_S) in solid sludge was basically the same during ozonation. The bio-available phosphorus increased with ozone dosage. The proportion of TP_S increased from 73.60% in the original sludge to 86.27% with 0.15 g·g^-1 ozone, reaching 20.74 mg·g^-1 of P content. TP_L in liquid was mainly from the destruction of extracellular polymer structure and the dissolution of phosphorus-containing substances, with a rate of 0.0324 g TP_L of 1 g MLSS.