Adsorption of Cadmium on Degraded Soils Amended with Maize-Stalk-Derived Biochar

Abstract

Biochar has been extensively proven to distinctively enhance the sorption capacity of both heavy metal and organic pollutants and reduce the related environmental risks. Soil pollution and degradation widely coexist, and the effect of biochar addition on adsorption behavior by degraded soils is not well understood. Four degraded soils with different degrees of degradation were amended with maize-stalk-derived biochar to investigate the adsorption of cadmium using batch methods. The maximum adsorption capacity (Qm) of degraded soil remarkably decreased in comparison with undegraded soil (5361 mg·kg−1→170 mg·kg−1), and the Qm of biochar increased with increasing pyrolysis temperature (22987 mg·kg−1→49016 mg·kg−1) which was much higher than that of soil. The addition of biochar can effectively improve the cadmium adsorption capacity of degraded soil (36–328%). The improving effect is stronger when increasing either the degradation level or the amount of added biochar, or the pyrolysis temperature of biochar. Contrary to the general soil–biochar system, adsorption of Cd was not enhanced but slightly suppressed (7.1–36.6%) when biochar was incorporated with degraded soils, and the adsorptivity attenuation degree was found to be negatively linear with SOM content in the degraded soil–biochar system. The results of the present study suggest that more attention on the adsorption inhibition and acceleration effect difference between the soil–biochar system and the degraded soil–biochar system is needed.

Halophyte Planting Improves Saline-Alkali Soil and Brings Changes in Physical and Chemical Properties and Soil Microbial Communities

“…Su et al reported that higher soil moisture and OM contents favoring biodegradation in soil and improving microbial activity and soil adsorption [25,26]. Previous studies have shown that if the vegetation litter is reduced, soil OM cannot be replenished [27]. At the same time, wind erosion and freeze-thaw action continuously accelerate the mineralization of soil OM, which will greatly reduce soil fertility [28,29].…”

Determination of the Environmental Pollution Potential of Some Herbicides by the Assessment of Cytotoxic and Genotoxic Effects on Allium cepa

“…However, pollution varies with the change of the spatial position, and the pollution of the soil determined through statistical analyses of solely the sampling points cannot reflect the spatial distribution characteristics of the whole study area [43]. The environmental risk of pollutants is influenced by their absorption behaviour [44].…”

Influence of Pyrolysis Temperature on Cadmium Removal Capacity and Mechanism by Maize Straw and Platanus Leaves Biochars

“…Biochar, a carbon-rich material, has been successfully used for carbon sink, climate change mitigation and soil remediation [ 3 , 4 , 5 ]. In recent years, biochar has been successfully used to remove heavy metal from wastewater, including Cd [ 6 , 7 , 8 ].…”