城市污泥资源化利用技术研究进展

Research progress of municipal sludge resource utilization technology

城市污泥成分复杂多变,除含有大量有机质、植物营养元素外,还可能浓缩重金属,微量有机污染物以及少量病原生物等有毒有害物质。随着我国环保要求的提高,污泥资源化利用已成为污泥安全处理处置的趋势。综述了城市污泥的组成、环境风险、传统污泥处置方法与资源化利用技术,重点阐述了污泥堆肥、建材利用、沼气利用及生物炭利用等污泥资源化利用技术的研究现状。其中,污泥堆肥产品可作为营养土满足环境生态修复的需要;建材利用技术可在实现污泥减量化的同时减缓黏土资源的消耗;污泥沼气利用技术发展历史较长、相对成熟,可实现工程应用;污泥生物炭利用技术在园林绿化、作物种植、水污染和气体污染治理方面具有可观效益,形成“以废治废”的生态链。上述污泥资源化利用技术具有广阔的应用前景,有望真正实现环境、社会和经济的多重效益。然而目前还存在着相关处理技术不成熟、设备运行成本过高等问题,需要进一步开展理论、技术与设备方面的研究,降低投资与运营成本,使上述污泥资源化利用技术真正达到技术可行、经济合理。

The composition of municipal sludge is complex and variable,which may contain a large amount of organic matter,plant nutrients,but also concentrated heavy metals,trace organic pollutants and a small amount of pathogens and other toxic and harmful substances.With the improvement of environmental protection requirements in China,sludge resource utilization has become the trend of safe sludge treatment and disposal.The composition of municipal sludge,environmental risks,traditional sludge disposal methods and resource utilization technologies were reviewed,and the current research status of sludge resource utilization technologies such as sludge composting,building materials utilization,biogas utilization and biochar utilization was highlighted.Among them,sludge composting products can be used as nutrient soil to meet the needs of environmental ecological restoration.Building material utilization technology can reduce the consumption of clay resources while achieving sludge reduction.Sludge biogas utilization technology has a long history of development and mature,which can realize engineering applications.Sludge biochar utilization technology has considerable benefits in landscaping,crop cultivation,water pollution and gas pollution control,forming an ecological chain of“treating waste with waste”.The abovementioned sludge resource utilization technologies have broad application prospects and are expected to achieve multiple benefits of environment,society and economy.However,there are still problems such as immaturity of treatment technologies and high operation costs,which require further research on theory,technology and equipment to reduce investment and operation costs,so that the above sludge resource utilization technologies can truly achieve technical feasibility and economic rationality.