Effects of Modified Biochar on the Mobility and Speciation Distribution of Cadmium in Contaminated Soil

Abstract

Cadmium-contaminated soil poses a threat to the environment and human health. Biochar materials have received widespread attention as an in situ immobilizer for the efficient remediation of heavy-metal-contaminated soils. In this study, a modified biochar material (E–CBC) was developed for the immobilization of Cd in contaminated soil. E–CBC was characterized by XPS, SEM, BET, and FTIR. The effects of pristine biochar (BC) and E–CBC on soil physicochemical properties (pH and soil organic matter (SOM)), CaCl2-extractable Cd, total characteristics leaching procedure (TCLP) Cd, and speciation distribution of Cd were studied by incubation experiments. The results showed that the application of BC and E–CBC increased soil pH slightly and SOM significantly. A 2% dosage BC and E–CBC treatment reduced CaCl2-extractable Cd by 14.62% and 91.79%, and reduced TCLP Cd by 9.81% and 99.8%, respectively. E–CBC was shown to effectively induce the transition of Cd in the soil to a stable state. The application of a 0.25% dosage of E–CBC reduced the acid-extractable fraction of Cd from 58.06% to 10.66%. The functional groups increased after modification and may play an important role in the immobilization of Cd in the contaminated soil. In conclusion, E–CBC is a promising in situ immobilizer for the remediation of Cd-contaminated soil.

Novel Adsorbents for Environmental Remediation

“…This char was used to immobilise cadmium (Cd) and copper (Cu) from soil [11]. The use of chitosan-ethylenediaminetetraacetic acid (EDTA)-modified biochar [12,13] and rubber-seed-shell-based activated carbon [14] was also reported for the remediation of heavy metals in soil and water, in addition to CO 2 capture. Additionally, Li et al prepared a sorbent-iron-modified bacterial biomass-for the removal of antimony(III), and they argued it had a higher sorption capacity than some previously reported sorbents [15].…”

Effects of biochar and modified biochar on Chromium contaminated soil properties

“…OIL is a critical life-support system of planet Earth, which supports essential ecosystem services such as biodiversity, biogeochemical cycling, and water cycling. Apart from this soil is still a fundamental resource of production for agriculture [1][2][3][4][5]. Contamination of soil by organic and inorganic pollutants has become a global concern for the last couple of decades.…”