基于生命周期评价的土壤热脱附修复技术绿色可持续性分析

GREEN SUSTAINABILITY ANALYSIS OF SOIL THERMAL DESORPTIONREMEDIATION TECHNOLOGY BASED ON LIFE CYCLE ASSESSMENT

基于全生命周期评价的产品碳足迹在线分析系统eFootprint和中国华东区域5个污染土壤异位热脱附修复工程案例,从环境影响潜值角度评估了热脱附技术的绿色可持续性。结果表明,天然气、活性炭和电力污染是土壤热脱附修复技术的主要环境影响因素,其累积环境影响频率分别为95.00%,97.03%,92.82%。对于初级能源消耗潜值、气候变化潜值和臭氧层消耗潜值指标来说,土壤预处理是主要影响阶段,贡献率分别为51.37%,59.09%,53.86%。对于水资源消耗潜值和竞争-土地使用潜值指标来说,尾气处理是主要影响阶段,贡献率分别为55.1%和99.92%。在污染土壤预处理过程中,柴油对臭氧层消耗潜值和竞争-土地使用潜值指标的影响最大,贡献率分别为83.68%和100%;在主处理过程中,对于所有的可持续性和绿色性指标,天然气均是主要贡献因素,所有指标的贡献率均超过60%;在尾气处理过程中,废水对初级能源消耗潜值、非生物质资源消耗潜值、气候变化潜值、酸化潜值、富营养化潜值和可吸入无机物潜值的贡献较大,贡献率分别为75.90%,66.92%,81.90%,91.98%,93.61%,90.76%。综合考虑各阶段的影响,可采用电加热或其他清洁能源来代替传统的柴油加热,研究和推广可回收或可生物降解的聚偏二氟乙烯膜材料,开发和使用低钙或者无钙的土壤改良剂以减少对生石灰的需求,逐步增加可再生能源在热脱附过程中的应用比例等,以改善能源和修复效率,减少环境排放,从而提高热脱附技术的绿色可持续性。

Based on the whole life cycle assessment software eFootprint and five cases of ectopic thermal desorption remediation projects of contaminated soil in East China,the green sustainability of thermal desorption technology was evaluated from the perspective of environmental impact potential.The results showed that natural gas,activated carbon and electric power were the main environmental factors affecting the thermal desorption remediation technology,and the cumulative environmental impact frequencies were 95.00%,97.03%and 92.82%,respectively.For primary energy consumption potential,climate change potential and ozone layer depletion potential,soil pretreatment was the main influence stage,contributing 51.37%,59.09%and 53.86%,respectively.For water resources consumption potential and competition-land use potential,exhaust gas treatment is the main influence stage,accounting for 55.1%and 99.92%,respectively.During the pretreatment of contaminated soil,diesel oil had the greatest influence on the ozone layer depletion potential and competition-land use potential,accounting for 83.68%and 100%,respectively.In the main treatment process,natural gas is the main contributing factor for all sustainability and green indicators,and the contribution rate of all indicators is more than 60%.In the process of tail gas treatment,the contribution of wastewater to primary energy consumption potential,non-biomass resources consumption potential,climate change potential,acidification potential,eutrophication potential and inhalable inorganic potential was 75.90%,66.92%,81.90%,91.98%,93.61%and 90.76%,respectively.Taking into account the impact of each stage,electric heating or other clean energy sources can be used instead of traditional diesel heating,and research and promotion of recycled or biodegradable polyvinylidene fluoride membrane materials can be carried out,developing and using low or calcium-free soil amendment to reduce the need for quick lime,and gradually increasing the proportion of renewable energy used in the thermal desorption process to improve energy and remediation efficiency and reduce environmental emissions,therefore,the green sustainability of thermal desorption technology can be improved.