Assessing the capacity of biochar to stabilize copper and lead in contaminated sediments using chemical and extraction methods

Ameliorating a sandy soil using biochar and compost amendments and their implications as slow release fertilizers on plant growth

“…However, these results recommend the usage of biochar as a slow release fertilizer and its effect can extend to the second growing season. Probably, the degree of biochar stability depends mainly on the dose of applied biochar as well as the incubation period (Wang et al, 2019). Thus, future studies are needed to investigate the effects of aging (from fresh to old) of the biochar on the physiochemical properties of the amended soils (Jien, 2019).…”

“…Biochar is a carbon rich product which is derived from the pyrolysis of organic carbon under limited oxygen conditions ( Nguyen et al, 2019). This amendment can stabilize and reduce the availability of the potentially toxic metals while remediating contaminated soils because of its high adsorption capacity (Abdelhafez et al, 2014 andMohamed et al, 2018;Wang et al, 2019). Probably, this mechanism affects, on the other hand, the availability of soil nutrients in arid soils.…”

“…NPK in readily available forms for plant uptake (Rens et al, 2018); however, some others pointed out to negative implications of biochar on inducing N deficiency in plants e.g. lettuce (Kim et al, 2015).Also, increasing soil pH which is considered the main factor for stabilizing PTEs in contaminated soils (Wang et al, 2019) might negatively reduce the availability of P (Cerozi and Fitzsimmons, 2016) and micronutrients in soils (Rutkowska et al, 2014). To what extent can biochar decrease the availability of soil nutrients for the grown plants e.g.…”

Contaminated aquatic sediments

“…Sulfur moiety, polymer properties, MeHg complexation, and Hg species might influence the sorption and bioavailability potential and from the research, it could be postulated that plastic waste might act as good sorption agent for Hg species in the sediment. Wang, Ren, et al (2019) assessed the potential of palm sawdust-based gasification biochar (SBIO, surface area 90.4 m 2 /g) for enhancing the binding of Cu and Pb in contamination sediment from three locations, that is, inner-city river (CR), a standby reservoir (SR), and an artificial lake (AC) by applying four extraction methods to understand the bonding strength, mobility, bioavailability, and eco-toxicity of metals in the aquatic ecosystem where pore water concentration and leachability of both metals were decreased with increasing incubation time and SBIO dosage although stability of Pb was effected by pH, ORP, SBIO amount, and incubation time. Biochar addition had reinforced natural stabilization process by redistributing the metals; however, adsorption was the major metal immobilization process by formation of electrostatic complexes by ion exchange, surface complexation with major functional groups of biochar, dispersion of metals into inner surface and inner surface complexation.…”

Contaminated aquatic sediments

“…They found that more than 80% of the Hg adhered to the biochar on the surface and within the pores. Wang, Ren, et al (2019) studied the effectiveness of biochar made with palm sawdust in addressing Cu and Pb in contaminated sediment. They observed that adsorption increased with higher amounts of biochar and contact time and that pH, metal crystallization, and adsorption were the main drivers.…”