Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička Cesta 54, HR-10000, Zagreb, Croatia.
Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička Cesta 54, HR-10000, Zagreb, Croatia.
Chemosphere. 2022 Jul;299:134410. doi: 10.1016/j.chemosphere.2022.134410. Epub 2022 Mar 25.
Coal combustion generates almost 40% of world's electricity. However, it also produces 1.1 billion tons of coal combustion residues (CCR) annually, half of which end up in landfills. Although current regulations require proper lining and monitoring programs, the ubiquitous old, abandoned landfills are often not lined nor included in these programs. In addition, the total number of coal ash disposal sites and their status in the world is unknown. Therefore, this article reviews the environmental damage caused by CCR and three commonly used risk assessment methodologies: leaching assessment, groundwater assessment, and toxicity testing. Leaching methods are usually the first step in coal ash risk assessment, however, a large number of methods with different parameters make a comparison of data difficult. Groundwater pollution is commonly detected near coal ash disposal sites, but other anthropogenic activities may also exist nearby. Therefore, multivariate statistical methods and isotope traces should be used to differentiate between different sources of pollution. So far, both stable (δO, δD, δB, δS, δLi) and radiogenic (Sr/Sr, Pb/Pb) isotopes have been successfully used as coal ash pollution tracers. Coal ash also negatively affects biota, reduces the diversity of organisms, affects children's health, and increases the risk for developing various diseases. Toxicity studies are great for early screening of coal ash safety; however, they provide no insights into mechanisms causing the adverse effects. Future directions are also proposed, such as the development of new 'low-level' detection methods for coal ash pollution and sustainable and selective method for recovery of critical elements.
煤炭燃烧产生了全球近 40%的电力。然而，每年也产生了 11 亿吨的煤燃烧残渣（CCR），其中一半最终被填埋。尽管现行法规要求进行适当的衬垫和监测计划，但普遍存在的旧的、废弃的垃圾填埋场通常没有衬垫，也没有纳入这些计划。此外，全球煤灰处理场的数量及其状况也不得而知。因此，本文综述了 CCR 造成的环境损害，以及三种常用的风险评估方法：浸出评估、地下水评估和毒性测试。浸出方法通常是煤灰风险评估的第一步，然而，大量具有不同参数的方法使得数据的比较变得困难。煤灰处理场附近通常会检测到地下水污染，但附近也可能存在其他人为活动。因此，应该使用多元统计方法和同位素示踪剂来区分不同来源的污染。到目前为止，稳定同位素（δO、δD、δB、δS、δLi）和放射性同位素（Sr/Sr、Pb/Pb）都已成功地用作煤灰污染示踪剂。煤灰还会对生物群产生负面影响，降低生物多样性，影响儿童健康，并增加患各种疾病的风险。毒性研究对于早期筛选煤灰的安全性非常有用，但它们不能深入了解导致不良反应的机制。还提出了未来的发展方向，例如开发新的煤灰污染“低水平”检测方法和对关键元素进行可持续和选择性回收的方法。
