我国城镇污泥新污染物的赋存特征、治理现状及防控策略

Occurrence characteristics,treatment status and prevention and control strategies of new pollutants in urban sludge in China

综述了我国城镇污泥中新污染物的赋存特征,梳理了污泥处理处置对新污染物的去除特征,提出了污泥中新污染物治理现状的不足,凝练了污泥新污染物治理研究仍存在的关键科学问题,由此提出了防控策略。从各类新污染物在污泥中的存在水平来看,抗生素检出率较高,浓度高达μg/g dw;全氟化合物和内分泌干扰物浓度处于ng/g dw级别;微塑料存在水平普遍较高,丰度范围为1600.00~56400.00个/kg dw。污泥厌氧消化和好氧堆肥处理技术能够有效控制和削减污泥中存在的新污染物。不同新污染物的去除效果受污染物的理化性质、生物利用性等污染物自身条件的影响。未来可进一步研究多种新污染物共存体系的去除路径及降解机制,可采用优化堆肥条件和引入特定的微生物菌种相结合的策略来提高新污染物的降解效率,从而获得较安全的堆肥产物。土地利用是污泥堆肥产物的最终去向,我国亟须开展对污泥土地利用过程中各类新污染物的生态风险评价,并建立相应的限量控制标准,以便为污泥土地安全利用提供科学依据。

Sludge is an important"sink"of emerging pollutants and the ecological risk caused by emerging pollutants is the key to the resource utilization and safe disposal of sludge.This paper deals with the occurrence characteristics of emerging pollutants in urban sludge in China,summarizes the removal characteristics of emerging pollutants by sludge treatment and disposal,puts forward the shortcomings in the current situation to treat emerging pollutants in sludge,further condenses the key scientific problems still existing in the treatment of emerging pollutants in sludge,and thus puts forward the prevention and control strategies.From the perspective of the existence level of various emerging pollutants in sludge,the detection rate of antibiotics is high,with a concentration of up toμg/g dw;concentrations of perfluorocarbons and endocrine disrupting agents are in the level of ng/g dw;the existence level of microplastics is generally high,with an abundance range of 1600.00~5640.00/kg dw.Sludge anaerobic digestion and aerobic composting treatment technologies can effectively control and reduce the existence of emerging pollutants in sludge.The removal effects of different emerging pollutants are affected by the physical and chemical properties,bioavailability and other conditions of the pollutants themselves.Further research can be conducted on the removal paths and degradation mechanisms of a variety of emerging pollutants coexisting systems.The strategy of optimizing composting conditions and introducing specific microbial strains can be combined to improve the degradation efficiency of emerging pollutants,so as to obtain safer compost products.Land use is the final destination of sludge compost products.It is urgent to carry out ecological risk assessment of various emerging pollutants in the process of sludge land use and establish corresponding limit control standards,so as to provide a scientific basis for the safe use of sludge land.