Towards a Soil Remediation Strategy Using Biochar: Effects on Soil Chemical Properties and Bioavailability of Potentially Toxic Elements

Abstract

Soil contamination with potentially toxic elements (PTEs) is considered one of the most severe environmental threats, while among remediation strategies, research on the application of soil amendments has received important consideration. This review highlights the effects of biochar application on soil properties and the bioavailability of potentially toxic elements describing research areas of intense current and emerging activity. Using a visual scientometric analysis, our study shows that between 2019 and 2020, research sub-fields like earthworm activities and responses, greenhouse gass emissions, and low molecular weight organic acids have gained most of the attention when biochar was investigated for soil remediation purposes. Moreover, biomasses like rice straw, sewage sludge, and sawdust were found to be the most commonly used feedstocks for biochar production. The effect of biochar on soil chemistry and different mechanisms responsible for PTEs’ immobilization with biochar, are also briefly reported. Special attention is also given to specific PTEs most commonly found at contaminated soils, including Cu, Zn, Ni, Cr, Pb, Cd, and As, and therefore are more extensively revised in this paper. This review also addresses some of the issues in developing innovative methodologies for engineered biochars, introduced alongside some suggestions which intend to form a more focused soil remediation strategy.

Effect of different biochar particle sizes together with bio-organic fertilizer on rhizosphere soil microecological environment on saline–alkali land

“…Biochar is a stable carbon-rich product obtained from the thermochemical decomposition of organic biomasses in an oxygen-limited condition and has attracted extensive attention because of its role in environmental improvement (Lehmann et al, 2011;Joseph et al, 2015;Kumar et al, 2021). As it generally has excellent properties, including high stability (Duan et al, 2021), large specific surface area (Luo et al, 2019;Shen et al, 2019), and abundant surface functional groups (Akdeniz, 2019;Chen et al, 2019), biochar is now increasingly used as a soil amendment (Bilias et al, 2021). To date, it has been reported to affect various parameters, including N (Borchard et al, 2014), total phosphorus (P) (Zhang et al, 2016), pH (Haque et al, 2021), soil organic matter (OM) content (Laskosky et al, 2020), microorganisms (Ren et al, 2020), organic carbon (OC) (Zhang et al, 2021), alter crop yield (Hossain et al, 2010;Sun et al, 2014;Ye et al, 2019), and water holding capacity (Yu et al, 2013), and alleviate abiotic stress (Lashari et al, 2014;Akhtar et al, 2015;Razzaghi et al, 2019).…”

Soil Contamination by Heavy Metals and Metalloids

“…The application of low-cost and eco-friendly materials as immobilizing agents in HM/PTEs-contaminated soils has gained significant interest, and there is now an urgent need to understand their functionality in contaminated soils [15]. The extensive application of biochar, which acts as a contaminant scavenger, has received significant consideration for HM/PTE-contaminated soil remediation [16,17].…”

Knowledge Map of Spatial Planning and Sustainable Development: A Visual Analysis Using CiteSpace

“…Knowledge maps help us clearly review previous studies and forecast future development directions. The tool which helps make knowledge maps, such as CiteSpace, is used by many researchers around the world at present in various fields such as agriculture [148], food science [149,150], technology [151][152][153][154][155], planning [156][157][158][159], tourism [160], energies [161,162], medicine [163,164], health [165,166], ecology [167][168][169][170][171], and so on [172][173][174]. As an important tool for sustainable development, spatial planning has undoubtedly attracted the attention of many countries.…”