Ecological remediation of urban legacy pollution: Developing a neosoil for marginal brownfield bioremediation

运河作为一种重要的绿色空间越来越受到重视，它在城市地区提供娱乐和生态效益（威廉姆斯等人，2010年）。然而，他们的工业历史留下了污染土壤和沉积物的遗产，以及相关的水质差。因此，英国大部分运河网络在适合公众使用之前需要对重金属进行重大修复。清理的主要方法是挖掘和异地补救（Bromhead等人，1994年）。对于边际公共土地来说，这往往过于昂贵，因此需要一种替代的、就地的、低成本的方法来使这些地区重新得到有益的利用。堆肥技术的最新进展为改善原位生物修复的环境可持续性提供了机会（Zhou等人，2022年）。天然螯合剂如氨基酸（Dolev等人，2020）和其他低分子量有机酸（Wang等人，2019）提供了有希望的新方法来提高修复效率，而不会对合成的不可生物降解螯合剂（如EDTA）提供的土壤功能和结构产生负面影响（Jelusic和Lista 2014; Bloem等人，1917年）。同样，具有草酸、半乳糖酸和甘油酸含量高的根系分泌物的植物已被证明可以有效地去除污染土壤中的铅（Luo等人，2017年）。大多数重金属修复研究都集中在单一或有限数量的污染物上。然而，这并不反映现场遗留污染，即在单个场地通常存在多种污染物。例如，伯明翰Digbeth的大联盟运河有9个重金属浓度超过规定值（图1）。该项目的新奇在于通过生产低成本的“新土壤”来去除多种污染物，这种土壤可用于英国类似的污染场地。该项目的主要目的是将受污染的城市边缘土地重新投入公共使用。因此，该项目将：（1）确定土壤改良剂（如天然/螯合/有机）的最佳组合，用于土壤中重金属污染物的生物和植物修复;（2）检查修复的潜在负面后果，包括通过土壤化学变化增加流动性，沥滤和分配到地上生物量;（3）创建一个新土壤模板，用于英国类似污染场地的低成本修复。

Canals are increasingly valued as an important green space providing recreational and ecological benefit in urban areas (Williams et al.,2010). However, their industrial past has left a legacy of polluted soils and sediments with associated poor water quality. As a result, large sections of the UK's canal network require significant remediation of heavy metals before being suitable for public use. The principal method of clean-up requires excavation and ex-situ remediation (Bromhead et al.,1994). This is often too costly for marginal public land and therefore an alternative, in-situ, low-cost method is needed to bring these areas back into beneficial use. Recent advances in composting technology offer an opportunity to improve the environmental sustainability of in-situ bioremediation (Zhou et al.,2022). Natural chelating agents such as amino acids (Dolev et al.,2020) and other low-molecular-weight organic acids (Wang et al,.2019) provide promising new ways to improve remediation efficiency without the negative impacts on soil function and structure afforded by synthetic, non-biodegradable chelators such as EDTA (Jelusic and Lista 2014; Bloem et al.,1917). Similarly, plants with root exudates high in oxalic, galactonic and glyceric acid have been shown to effectively remove lead in contaminated soil (Luo et al,.2017). Most research into heavy metal remediation is focused on a single or limited number of contaminants. However, this does not reflect in-situ legacy contamination where multiple contaminants are usually present at an individual site. For example, the Grand Union canal in Digbeth, Birmingham has nine heavy metal concentrations in excess of regulatory values (Fig.1). The novelty of this project is to focus on multi-contaminant removal via production of a low-cost "neosoil" that can be utilised at similarly contaminated sites in the UK. The project's principal aim is to bring contaminated urban marginal land back into public use. Accordingly, the project will: (1) identify the best combination of soil amendments (e.g. natural/chelate/organic) for bio- and phytoremediation of heavy metal contaminants in soils; (2) examine potential negative consequences of remediation including increased mobility via changes in soil chemistry, leaching and partitioning into aboveground biomass; (3) create a neosoil template for low-cost remediation of similarly contaminated sites within the UK.