基于分离预处理的城镇污泥原位资源化技术分析

Analysis of in-situ municipal sludge resource utilization technology based on separation pretreatment

结合污水处理厂生产运行情况,增加污泥分离预处理工序段,并耦合国内主流污泥处理技术,可补足现有工艺短板,实现污泥的高效精准资源化利用。通过破坏污泥中的胞外聚合物(extracellular polymeric substances,EPS)降低污泥黏性,实现对污泥有机物、无机盐类和砂组分的分离。分离后污泥有机物质量分数高于75%,热值稳定在12 MJ/kg以上,用作生物质燃料可自持燃烧;或无需添加辅料即可符合污泥堆肥的要求;或用作厌氧发酵沼气产量可提升至96.0 mL/g,且沼液浓度低,处理相对简单。分离出的铝铁盐可用作污水处理厂絮凝剂进行化学除磷,磷盐可回收作为园林绿化用磷肥原料,砂组分经脱水及自氧化干化后可用作建筑基材。

Sludge separation was added into pretreatment process of sewage treatment plants considering their operation status.Coupled with domestic mainstream sludge treatment technology,sludge separation can make up the existing shortcomings and realize the efficient and accurate resource utilization of sludge.Destroying the extracellular polymeric substance(EPS)in sludge can reduce the viscosity of sludge and separate organic matter,inorganic salts and sand out of sludge.After separation,the content of organic matter in sludge is more than 75%,and the calorific value is more than 12 MJ/kg.The treated sludge can be used as biomass fuel for self-sustaining combustion or sludge composting without adding auxiliary materials.And it can increase the biogas production in anaerobic fermentation to 96.0 mL/g,and lower the concentration of biogas slurry and the treatment difficulty.The separated aluminum and ferric salt are used as flocculants for chemical phosphorus removal in wastewater treatment plants.The phosphorus salt can be recycled as raw material of phosphorus fertilizer for landscaping.The sand component can be used as building material after dehydration and self oxidation drying.