城市污水有机物回收——捕获技术研究进展

Organics recovery from municipal wastewater:research advances in capture technologies

当今的城市污水处理系统中,有机物去除过程的高额能耗和碳排放问题逐渐被重视。随之,兼具环境意义和经济效益的有机物回收理念日益受到关注。而将污水中的有机物富集或浓缩到易利用的浓度,也即污水碳捕获,是影响其回收技术经济性的关键。大众熟知的水处理工艺,如膜分离、高负荷活性污泥法、絮凝等,凭借着高的有机物保留特性而被重新认识。本文根据这些工艺在捕获过程中有机物的转移方向,将它们归类为“转移聚集”(主要是高负荷活性污泥法、絮凝)和“被动富集”(主要是膜分离)两大类进行讨论。在介绍它们各自捕获机制、捕获率、研究进展的基础上,讨论进一步提升捕获率的途径及其在规模化应用中需要克服的问题。随后本文综述了捕获产物的能源化与产品化途径,并认为根据其性质选择合适的预处理是提升资源化程度的关键。最后围绕碳捕获工艺的成熟度、能耗及运行费用,讨论了生活污水资源化工艺流程的构建。

Nowadays,the problem of high energy consumption and carbon emission during the organic matter removal in municipal wastewater treatment plant becomes increasingly obvious.Subsequently,the concept of organics recovery,which has both environmental and economic profits,attracted more and more attention.Efficient capture of organic matter from low-intensity municipal wastewater to generate high concentration organics,determines the economic and technical feasibility of organics recovery.Many well-known water treatment processes,such as membrane filtration,high-loaded activated sludge process,flocculation,have been re-recognized and applied to organics capture due to their high organic matter retention characteristics.In this paper,according to the concentration process of organic matter in these technologies,they were divided into two categories:“directional aggregation”and“passive accumulation”.Based on understanding their capture mechanism,this paper further discussed the approaches to improve their capture efficiency and short slabs that need to overcome for large-scale application.Then,this paper summarized the recovery methods of the concentrated organics,and pointed out that the key of maximum recovery is to select the appropriate pretreatment according to the characteristics of concentrated organics.Finally,based on the technology maturity,energy consumption and operation cost of organics capture process,the feasibility of wastewater treatment system aiming at resource recovery was prospected.