Department of Chemical Engineering, CRETUS Institute, Univesidade de Santiago de Compostela, E-15782, Santiago de Compostela, Galicia, Spain.
Department of Chemical Engineering, CRETUS Institute, Univesidade de Santiago de Compostela, E-15782, Santiago de Compostela, Galicia, Spain.
J Environ Manage. 2021 Feb 1;279:111594. doi: 10.1016/j.jenvman.2020.111594. Epub 2020 Nov 5.
Wastewater treatment plants (WWTPs) have been developed as multifunctional systems that aim to eliminate pollutants present in wastewater, manage the sludge produced and improve energy efficiency. Specifically, sludge management accounts for the largest share in operational costs. Considering the relevant role of sludge treatment within the overall management scheme, this study aims to evaluate different alternatives and strategies for sludge management and treatment from the perspective of life cycle analysis, with special emphasis on those options that reduce environmental impacts and economic costs. Two pre-treatments (chemical or thermal) and two post-treatments (composting unit followed by land application or incineration) were evaluated to improve the eco-balance of the anaerobic digestion (AD) process in terms of operational (biogas production and digested sludge), environmental and economic indicators. According to the results obtained, both sludge pre-treatment alternatives proved to be an adequate alternative to improve biogas production without negatively affecting environmental and economic impacts. Finally, if the final disposal of the digestate is analysed, its application to the soil as a biofertiliser is recommended, since it presents a better environmental profile than incineration.
污水处理厂（WWTP）已发展成为多功能系统，旨在消除废水中的污染物、管理产生的污泥并提高能源效率。具体来说，污泥管理在运营成本中占比最大。考虑到污泥处理在整体管理方案中的相关作用，本研究旨在从生命周期分析的角度评估污泥管理和处理的不同替代方案和策略，特别关注那些能够减少环境影响和经济成本的选择。评估了两种预处理（化学或热）和两种后处理（堆肥单元后进行土地应用或焚烧），以改善厌氧消化（AD）过程在操作（沼气产生和消化污泥）、环境和经济指标方面的生态平衡。根据获得的结果，两种污泥预处理方法都被证明是一种提高沼气产量的有效替代方法，而不会对环境和经济影响产生负面影响。最后，如果分析消化物的最终处置，建议将其作为生物肥料施用于土壤，因为它比焚烧具有更好的环境效益。
