不同污泥处理与处置工艺的碳排放

Review of carbon emission in the process of sludge treatment and disposal

针对目前主流的污泥处理处置工艺,总结了各工艺碳排放情景及其影响因素.好氧堆肥、干化、土地利用、焚烧的碳主要以CO2的形式排放;而厌氧消化和填埋的碳排放以CH4为主.好氧堆肥的CO2排放当量较低,填埋的CO2排放当量较高.好氧堆肥、厌氧消化、填埋工艺分别可以通过改善通风状况、前处理和不同类型污泥联合处理、覆盖有机材料等方法实现碳减排.而降低能耗是干化和焚烧工艺碳减排的有效措施.土地利用可增加生物量,因此增加了碳汇能力.采用好氧堆肥-土地利用工艺路线处理处置污泥是减少碳排放的重要途径.

This study focuses on the problem of carbon emission （CO2 and CH4 as the main greenhouse gases） during the process of sludge treatment and disposal by summarizing its quantity and influential factors.CO2 was the main C compound emitted during composting,drying （bio-drying and thermal drying）,land application and incineration,while CH4 was the major species during anaerobic digestion and landfilling.Composting landfills produced lower carbon emissions,while the landfills carbon emission was higher than other methods.Carbon emission can be reduced by improving aeration conditions during composting,pre-treatment and co-digestion of various sludges during anaerobic digestion and providing an organic cover in the landfill.Considering the technology of drying and incineration,reduction of energy consumption could efficiently control carbon emission.Land application produced negative carbon emission in the long term.A combination of composting and land application was the optimal scheme to reduce carbon emission during the process of sludge treatment and disposal.