基于湖泊底泥磷释放机制的剩余污泥磷回收的生物与物理过程强化

In China, more than 720000 ton P/a is available in the P-rich waste activated sludge (WAS) from municipal wastewater treatment plant. But the P release and recovery efficiency are both very low using traditional sludge anaerobic digest process. The species and fraction of the phosphorus in both WAS and lake sediments are similar, as well as the existence environmental conditions of the two kinds of sludge. Based on the mechanism of P release from lake sediment, the main objective of this project is to improve the simultaneous release of multi P species in the sludge using high voltage pulsed (HVP) plasma technique combined with anaerobic fermentation. The fermentation is to be controlled at acidic fermentation phase to induce the simultaneous release of organic and inorganic P. The mechanism of the HVP effect on the microorganism cell and P release is to be studied by relation investigation between the shape and bioavailability of the sludge before and after HVP treatment. P species fractions in the solid and liquid phase are to be analyzed to study the possible interaction and transformation of the species. Bacteria colony structure and pH control are to be used to enlarge the P release to the biggest extend. The result will be useful to the reuse of the P-rich WAS.

我国污水厂产生的富磷剩余污泥中可回收的磷超过72万吨P/年，但传统污泥厌氧消化过程磷释放、回收效率很低。剩余污泥与湖泊底泥磷的赋存形态、释磷环境相类似，本课题以富磷剩余污泥为研究对象，以促进污泥中多形态磷的同步释放为主要目标，基于湖泊底泥磷释放机制，创新性地提出以高压脉冲等离子体物理场预处理耦合污泥厌氧发酵工艺为技术手段，通过控制污泥厌氧发酵在产酸阶段，诱导污泥中聚磷、有机磷、无机磷的同步释放；通过解析高压脉冲预处理前后，污泥中微生物的形态指标和可生化性指标变化的相关关系，揭示高压脉冲对不同种微生物细胞的作用机制及其与厌氧发酵过程释磷效率之间的构效关系；通过考察污泥厌氧水解、产酸阶段固、液两相中磷的形态分布，揭示厌氧发酵过程各形态磷之间的相互转化、释放规律和最终归趋；通过体系微生物菌群调控、pH值调控，实现聚磷、有机磷、无机磷同步释放。

本课题以富磷剩余污泥为研究对象，以促进污泥中多形态磷的同步释放为研究目标，以高压脉冲等离子体物理场、pH值调控、过硫酸钾和电解等预处理耦合污泥厌氧发酵工艺为技术手段，通过控制污泥厌氧发酵在产酸阶段，诱导污泥中有机磷、无机磷的同步释放，研究结果表明预处理方法均具有一定的促进作用，揭示了厌氧发酵过程各形态磷之间的相互转化、释放规律和最终归趋；同时借助水热碳化和焚烧技术，并结合外加化学试剂的作用，实现了剩余污泥中磷形态的定向调控和重金属含量的降低，探究了水热技术对污泥中磷和重金属行为的影响及作用机制，以期实现富磷剩余污泥中磷的资源化回收。