水处理集成微藻生物柴油生命周期系统环境影响评价

Environmental impact assessment of water treatment integrated microalgae biodiesel life cycle system

采用生活废水的二级出水培养微藻可有效提高微藻生物柴油生产过程的环境效益,降低其环境影响。本文基于生命周期分析原理,针对结合了废水培养微藻的两种微藻生物柴油生产技术路线,即传统路线和热解酯化路线,建立了环境影响评价模型;提出了水处理集成微藻生物柴油生命周期系统评价的水处理过程替代效应的概念及其环境效益定量评价方法;通过计算对比了基于新鲜水培养微藻的两种技术路线的总环境影响指数和废水培养微藻的两种技术路线的环境效益,表明热解酯化工艺结合废水培养微藻路线相较其他工艺路线具有最小的环境影响,表明水处理过程替代效应在水处理集成微藻生物柴油生命周期系统评价中的有效性和必要性。

Cultivating microalgae by the secondary effluent of domestic wastewater can effectively increase the environmental benefits and reduce the environmental impact of the microalgae biodiesel production processes. Based on the life cycle analysis principle, a method for the assessment of environmental impact for two microalgae biodiesel production technical routes, namely a traditional route and a pyrolysis esterification route, both combined with wastewater microalgae cultivation, was proposed in this paper. To ensure the objectivity of the evaluation of the environmental impact, a concept of "water treatment process replacement effect" for the water treatment integrated microalgae biodiesel life cycle system was proposed, and a quantitative method for estimating the environmental benefit of this effect was implemented into the proposed assessment method. To validate the proposed method, the total environmental impacts of the two technical routes based on fresh water cultured microalgae and those based on wastewater culture were calculated and compared. The results showed that the pyrolysis esterification process combined with the wastewater culture microalgae route has minimal environmental impact compared to the other routes, suggesting that the water treatment process replacement effect is essential in the water treatment integrated microalgae biodiesel life cycle system.