Alteration of mixture toxicity in nonferrous metal mine tailings treated by biochar

Bioremediation techniques for the treatment of mine tailings: A review

“…In case of mine tailings, metal dominates the pollutants, such that complete elimination of metal contaminants from the environment is Husson et al, 2019 not feasible. Hence, detoxification of the metal via ionic or physical changes and immobilization of the same through encapsulation, chelation, and precipitation within cells or in the soil are the options for its toxicity remediation (Becerra-Castro et al, 2012;Gu et al, 2020;Khan et al, 2020). Researchers have explored various soil treatments for immobilization of labile metals along with bioremediation.…”

“…After extraction of the target mineral of the mining site generally, the waste materials, which include crushed rock, dug out and dumped soil, pit water, and disregarded trace elements, are termed mine tailings (Bryan et al, 2006;Gu et al, 2020). Removal of topsoil horizon containing microbes, nutrients, seeds as well as humic substances, is dependent on initiation by the mining operation.…”

The Effects of Rabbit Manure-Derived Biochar on Soil Health and Quality Attributes of Two Mine Tailings

“…In addition, several investigations have been performed with biochars from manure waste [22][23][24] and their potential to enhance plant growth. The addition of biochar to metal-contaminated soils can enhance plant yield, due to the reduction of bioavailable fractions of metals and the improvement of soil physical properties [25][26][27][28][29][30][31].…”

“…For example, Tu et al [35] concluded that the application of straw biochar (rate: 5%) reduced the labile and bioavailable fraction of Cu and Cd and, at the same time, increased both catalase and urease activities; Wen et al [36] observed, after the addition of wood biochar (rate: 3%) in a contaminated paddy soil, a reduction in the available forms of As, Cd and Pd together with an increase in both catalase and urease activities. Gu et al [31] emphasized the complexity of finding an overall trend of biochar on particular soil enzymes as each enzyme activity might reflect only a particular cellular function in response to the biochar amendment. For this reason, these authors [31] used the geometric mean (GMea) as an indicator of microbial enzymatic activities, concluding that the enzymatic activities of mine tailing did not increase after biochar addition.…”

“…Gu et al [31] emphasized the complexity of finding an overall trend of biochar on particular soil enzymes as each enzyme activity might reflect only a particular cellular function in response to the biochar amendment. For this reason, these authors [31] used the geometric mean (GMea) as an indicator of microbial enzymatic activities, concluding that the enzymatic activities of mine tailing did not increase after biochar addition. Indeed, the development of soil quality indices, including the geometric mean of enzyme activities, has been extensively used to study the biochar influence on soil quality [32,37].…”