Abstract：
Chemical methods are expected to play an increasingly important role in carbon-neutral municipal wastewater treatment plants. This paper briefly summarises the enhancement effects of using iron salts in wastewater and sludge treatment processes. The costs and environmental concerns associated with the widespread use of iron salts have also been highlighted. Fortunately, the iron recovery from iron-rich sludge provides an opportunity to solve these problems. Existing iron recovery methods, including direct acidification and thermal treatment, are summarised and show that acidification treatment of FeS digestate from the anaerobic digestion-sulfate reduction process can increase the iron and sulphur recycling efficiency. Therefore, a novel applicable integrated process based on iron use and recycling is proposed, and it reduces the iron salts dosage to 4.2 mg/L and sludge amount by 80%. Current experimental research and economic analysis of iron recycling show that this process has broad application prospects in resource recovery and sludge reduction.
摘要：
化学方法有望在碳中性城市污水处理厂中发挥越来越重要的作用。本文简要总结了在废水和污泥处理过程中使用铁盐的增强效果。还强调了与广泛使用铁盐相关的成本和环境问题。幸运的是,从富铁污泥中回收铁为解决这些问题提供了契机。现有的铁回收方法，包括直接酸化和热处理，总结并表明，厌氧消化-硫酸盐还原过程中对FeS消化产物的酸化处理可以提高铁和硫的回收效率。因此,提出了一种基于铁使用和回收的新型适用集成工艺，铁盐用量减少到4.2mg/L，污泥量减少80%。目前铁回收的实验研究和经济分析表明，该工艺在资源化回收和污泥减量化方面具有广阔的应用前景。
