Resilience of Cd contaminated clay soil after nitric acid and acetic acid enhanced electrokinetic remediation. Issue 3 (June 2022)

• Record Type: Journal Article
• Authors: Xu, Haiyin; Zhang, Hongwei; Chen, Yalin; Huang, Jing; Wang, Ping; Luo, Yuanling; Huang, Chao; Yang, Yi
• Is Part Of: Journal of environmental chemical engineering. Volume 10:Issue 3(2022)
• Publication Date: 2022-06
• Subjects: Black locust tree -- Cd -- Electrokinetic -- Enhancing agents -- Micro-ecology -- Resilience; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2022.108071
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: Electrokinetic remediation (EKR) by enhancing agents is highly effective but induces rather large perturbations to the soil. The resilience after EKR is of paramount importance for soil environment sustainability. Here we assessed the resilience of Cd contaminated clay soil after HNO3 -EKR and HAc-EKR from the perspective of soil chemical property, enzyme activity, micro-ecology, and plant restoration. The results showed a V-shape pattern of pH, Cd fractions, beta-glucosidase, acid phosphatase (ACP), urease (URE), and inverted-V shape pattern of NO3 - and dissolved organic carbon occurred during the EKR and soil incubation. The high-throughput sequencing results suggested that HAc-EKR and Control (CK-Clean) soils shared 60.1 % operational taxonomic units (OTUs); however, only 33.5 % OTUs were shared by HNO3 -EKR soils and CK-Clean. Co-correlation networks revealed that the OTUs assigned to ACP and URE revealed a strongly bimodal response in Proteobacteria and Chloroflexi. Compared with HAc-EKR, HNO3 -EKR had a lower resilience and black locust growth rate, indicating that environmental managemental measures of neutralization, fertilization, and bactericides, were required after HNO3 -EKR. Our studies highlighted that ignoring the resilience might overestimate the impact of EKR on the soil. Graphical Abstract: ga1 Highlights: V-shape of pH, βGA, URE, and ACP occurred in EKR and soil incubation. Inverted-V of DOC due to HAc agent in EKR and GC process in soil incubation. Evolution of bacterial β-diversity in HNO3 -EKR was entirely different from HAc-EKR. OTUs associated with URE and ACP showed a bimodal response in Proteobacteria. Compared with HNO3 -EKR, HAc-EKR had a higher resilience and black locust growth rate.