State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; College of Environment, Zhejiang University of Technology, Hangzhou, 310014, Zhejiang, China.
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
Chemosphere. 2017 Mar;171:601-608. doi: 10.1016/j.chemosphere.2016.12.113. Epub 2016 Dec 27.
The effect of ethylene diamine tetraacetic acid (EDTA) addition on phosphorus release from biosolids and phosphate precipitates during anaerobic fermentation was investigated. Meanwhile, the impact of EDTA addition on the anaerobic fermentation process was revealed. The results indicate that EDTA addition significantly enhanced the release of phosphorus from biosolids, ferric phosphate precipitate and aluminum phosphate precipitate during anaerobic fermentation, which is attributed to the complexation of metal ions and damage of cell membrane caused by EDTA. With the optimal EDTA addition of 19.5 mM (0.41 gEDTA/gSS), phosphorus release efficiency from biosolids was 82%, which was much higher than that (40%) without EDTA addition. Meanwhile, with 19.5 mM EDTA addition, almost all the phosphorus in ferric phosphate precipitate was released, while only 57% of phosphorus in aluminum phosphate precipitate was released. This indicates that phosphorus in ferric phosphate precipitate was much easier to be released than that in aluminum phosphate precipitate during anaerobic fermentation of sludge. In addition, proper EDTA addition facilitated the production of soluble total organic carbon and volatile fatty acids, as well as solid reduction during sludge fermentation, although methane production could be inhibited. Therefore, EDTA addition can be used as an alternative method for recovering phosphorus from waste activated sludge containing ferric or aluminum precipitates, as well as recovery of soluble carbon source.
研究了乙二胺四乙酸（EDTA）的添加对生物固体和磷酸盐沉淀在厌氧发酵过程中磷释放的影响。同时，揭示了 EDTA 添加对厌氧发酵过程的影响。结果表明，EDTA 的添加显著增强了生物固体、磷酸铁沉淀和磷酸铝沉淀在厌氧发酵过程中磷的释放，这归因于 EDTA 对金属离子的络合作用和细胞膜的破坏。在最佳的 EDTA 添加量为 19.5mM（0.41gEDTA/gSS）时，生物固体中的磷释放效率达到 82%，远高于未添加 EDTA 时的 40%。同时，添加 19.5mM 的 EDTA 时，几乎所有的磷酸铁沉淀中的磷都被释放出来，而磷酸铝沉淀中的磷仅释放了 57%。这表明在污泥的厌氧发酵过程中，磷酸铁沉淀中的磷比磷酸铝沉淀中的磷更容易释放。此外，适当的 EDTA 添加促进了可溶性总有机碳和挥发性脂肪酸的生成，以及污泥发酵过程中的固体减少，尽管甲烷的产生可能会受到抑制。因此，EDTA 添加可以作为一种从含有铁或铝沉淀的废活性污泥中回收磷以及回收可溶性碳源的替代方法。
