我国圩畈地区典型城市生活污泥土地利用潜力分析

Potential analysis for the land application of municipal sewage sludge in plain polder area in China

污泥土地利用是我国鼓励和推广的污泥资源化路径。我国圩畈地区水土资源丰富,产业结构以农林业为主,为污泥土地资源化利用孕育了良好的条件。以圩畈地区典型城市六安市为例,充分挖掘城区及周边土地资源,结合其泥质特征,提出了污泥土地利用实施路径,包括现有处理工艺提升方案、科学的施用方法、跨界的商业模式和合理的价格机制。研究表明,六安市以其园林城市的优势,具有较好的污泥土地利用潜力,城区及周边区域的土地资源可作为消纳污泥处理产物的载体,但需要提升现有处理工艺和处理产物质量。通过后腐熟工艺和产品加工工艺进一步提升其稳定化水平,产物可满足土地改良和园林利用标准。在施用方法上,建议采用撒施基肥和追肥相结合的方式,分批次、分场景进行科学消纳。建议国家和地方加强污泥土地利用立法和标准的完善,做到有法可依、有规可循。并建立污泥处置责任主体和污泥管家模式,从污泥“产生”到“入土”进行全过程管理,持续跟踪土壤质量变化与环境风险评估,为长江大保护环境管理和执法部门提供数据支持和决策服务。

Land application of sewage sludge is an encouraged and popularized route of sludge utilization in China.In plain polder area,water and soil resources are abundant.Agriculture and forestry are the dominant industries,which breeds good conditions for land application of sludge.This work tapped into the urban and surrounding land resources in Lu'an city and proposed the implementation path of sludge application on land,including the existing treatment process improvement scheme,scientific application method,cross-industry business mode and reasonable price mechanism.The results show that Lu'an city,named as the Garden city,has a good potential for sludge land application.The rich land resources in the urban and surounding areas can be used as places to consume sludge treatment products under the premise of improving the quality of sludge products.Composting process can further enhance the products stabilization level and the products can meet the standards of land improvement and garden use.In terms of application methods,it was advised to combine the base fertilizer and topdressing to consume the sludge products by regulations in batches and scenes.It was strongly suggested that the state and local should strengthen the laws,regulations and standards of sludge land application.Meanwhile,the sludge responsibility subject and city keeper should be established to whole-process charge of sludge from"born"to"die",and follow the tracks of the soil quality variation,which provides data support and decisionmaking services for the management and law enforcement departments.