Biochar efficacy for reducing heavy metals uptake by Cilantro (Coriandrum sativum) and spinach (Spinaccia oleracea) to minimize human health risk

Effects of amendments on the bioavailability, transformation and accumulation of heavy metals by pakchoi cabbage in a multi-element contaminated soil

“…The application of the hardwood biochar decreased the concentrations of Zn and Cu, in cilantro by 37.1% and 42.5%, respectively as compared to the control. 10 The application of all the amendments decreased the concentrations of Zn and Cu in pakchoi cabbage, which was below the permissible limits of SEPA (20 mg kg À1 and 10 mg kg À1 ). The application of low-dose biochar and biochar combined with a silicate fertilizer reduced the As level in grain (brown rice) by 14-16%, but did not decrease the As level in rice straw and root.…”

“…Globally, the use of organic amendments to minimize the heavy metal mobility and bioavailability in contaminated soils has increased rapidly. 3,[10][11][12] Compared with other soil remediation agents, compost, biochar and humic acid have their own advantages. Biochar can persist in the soil for hundreds or even thousands of years.…”

“…13 It has highly porous structure, alkali and cation exchange capacity, contains a large number of carboxyl and hydroxyl groups, which can reduce the bioavailability of heavy metals, thus reducing plant absorption and food chain transfer. 10,[14][15][16] However, biochar can not only immobilize heavy metals, but simultaneously immobilize essential nutrients for plants, leading to the deciency of Ca, P, and N in plants, thus affecting the plant growth. 17 Compost is a cost-effective method given the low price of residues and by-products that can be used as soil amendments.…”

Moderate sewage sludge biochar application on alkaline soil for corn growth: a field study

“…Converting sewage sludge into sewage sludge biochar (SSB) has additional advantages such as volume reduction, pollutant elimination, and nutrient retention (Wu et al 2019). Additionally, some potentially toxic elements (PTEs: Cr, Mn, Ni, Cu, Zn, As, Cd, and Pb) in untreated sewage sludge can cause potential threats to humans via the food chain (Khan et al 2020). In our previous study, we studied the migration and transformation behavior of PTEs in the sewage sludge pyrolysis process from laboratory-to pilot-scale experiments, and found that most of the PTEs remained in the SSB and were converted from bioavailable fractions to a more stable fraction combined with silicate minerals (Li et al 2018a(Li et al , 2021Xie et al 2020a).…”

“…It has been reported that excess PTEs have a negative effect on vegetative growth. More specifically, excess Zn can cause chlorosis in plant leaves, excess Cu may cause negative effects on plant nutrients, and large amounts of Ni and Co can reduce seed germination and inhibit the growth of plant tissues (Khan et al 2020;Mohamed et al 2017). Therefore, several studies have been conducted to investigate the accumulation of PTEs in plant tissues after addition of biochar to soil.…”