Labianca Claudia, De Gisi Sabino, Todaro Francesco, Notarnicola Michele, Bortone Imma
Department of Civil, Environmental, Land, Building Engineering and Chemistry (DICATECh), Polytechnic University of Bari, Via E. Orabona n. 4, 70125 Bari, Italy.
Department of Civil, Environmental, Land, Building Engineering and Chemistry (DICATECh), Polytechnic University of Bari, Via E. Orabona n. 4, 70125 Bari, Italy.
Sci Total Environ. 2022 Feb 1;806(Pt 3):151257. doi: 10.1016/j.scitotenv.2021.151257. Epub 2021 Oct 25.
Contaminated sediments can pose long-term risks to human beings and ecosystems as they accumulate inorganic and organic contaminants becoming a sink and source of pollution. Compared to ex-situ technologies (i.e., dredging activities and off site treatments), in-situ capping (ISC) intends to minimize contaminated sediment mobilization and impact into the water column whilst treating contamination. Literature shows that numerous types of ISC amendments in presence of both organic and inorganic pollutants are investigated, although a few are contributions whose experiments have been designed and conducted with a view to future engineering. Against this background of shortcomings, this review paper intends to investigate ISC reliability, applicability and its long-term effectiveness, by also comparing reactive and physical ISCs. Additionally, an examination of the main numerical simulations applied to ISC technology was carried out. We found that activated carbon and organoclay resulted the most studied amendments for organically contaminated sediment, whereas biochar, clay minerals, and industrial-by products were more employed in presence of sediment contaminated by metal(loids). There is no better ISC system in absolute terms, since technological performance depends on many factors and only a few experimental investigations included a long-term modeling phase to predict ISC long-term efficiency. Most of numerical models included simplified transport equations based on diffusion and adsorption, and the goodness of fitting between experimental and modeled data was not always computed. The review finally discusses new research directions such as the need for long-term applications on field-scale and cap effectiveness in presence of site-specific tidal forces and currents.
受污染的沉积物会对人类和生态系统构成长期风险，因为它们会积累无机和有机污染物，成为污染的汇和源。与异位技术（即疏浚活动和场外处理）相比，原位覆盖（ISC）旨在在处理污染的同时，尽量减少受污染沉积物的移动及其对水柱的影响。文献表明，人们研究了在有机和无机污染物同时存在的情况下多种类型的ISC改良剂，不过只有少数研究是为未来工程设计和开展的实验。针对这些不足之处，本综述论文旨在通过比较反应性和物理性原位覆盖，研究原位覆盖的可靠性、适用性及其长期有效性。此外，还对应用于原位覆盖技术的主要数值模拟进行了考察。我们发现，活性炭和有机黏土是针对有机污染沉积物研究最多的改良剂，而生物炭、黏土矿物和工业副产品在受金属（类金属）污染的沉积物中应用得更多。绝对地说，不存在更好的原位覆盖系统，因为技术性能取决于许多因素，而且只有少数实验研究纳入了长期建模阶段来预测原位覆盖的长期效率。大多数数值模型都包含基于扩散和吸附的简化输运方程，而且并不总是计算实验数据与模型数据之间的拟合优度。本综述最后讨论了新的研究方向，例如在现场尺度进行长期应用的必要性，以及在存在特定场地潮汐力和水流的情况下覆盖层的有效性。
