Preparation, modification and environmental application of biochar: A review

Remediation of heavy metal contaminated soils by biochar: Mechanisms, potential risks and applications in China.

A critical review on the biochar production techniques, characterization, stability and applications for circular bioeconomy.

Nitrogen containing functional groups of biochar: an overview

Biochar as a low-cost adsorbent for aqueous heavy metal removal: A review

Mechanism of negative surface charge formation on biochar and its effect on the fixation of soil Cd

Contributions and mechanisms of components in modified biochar to adsorb cadmium in aqueous solution.

In recent years, biochar has attracted interest as a soil amendment. As biochar research has increased, the nutrient characteristics of biochar were gradually determined. Pyrolysis conditions are v...

Migration and Transformation Mechanisms of Nutrient Elements (N, P, K) within Biochar in Straw–Biochar–Soil–Plant Systems: A Review

To evaluate the agronomic potential of biochar, we prepared a series of biochars using rice straw waste under the limited oxygen cracking condition (CO2 or N2) and the different pyrolysis temperatures including 300, 400, 600, and 800 °C. The results showed that morphology structure, specific surface area, pore size distribution, and element contents of the biochars were superior to the biochars prepared under traditional inert atmosphere (N2) and the same four pyrolysis temperatures. In comparison with the rice straw, pore structure of biochars was mainly mesoporous and more developed, average pore size decreased, and BET-specific surface area increased with the increase of temperature from 300 to 800 °C. Biochars distributed abundant mesopores and macropores under 400 and 600 °C; the maximum macropores of the biochar were shaped under 600 °C. Concentration of phosphorus (P) and potassium (K) increased significantly with increasing temperature, while that of nitrogen (N) first increased and then decreased and reached a maximum at 400 °C. In addition, taking these physiochemical properties into consideration, we drew a conclusion that the optimum quality biochar could acquire under the work conditions of 400 °C and CO2 atmosphere, which was supposed to provide theoretical guidance for biochar returning to soil.

Morphology, pore size distribution, and nutrient characteristics in biochars under different pyrolysis temperatures and atmospheres

This article used novel non-magnetized and magnetized biochars prepared under a CO2 atmosphere returned to Cd-contaminated soil and compared these to the effects of conventional biochars prepared under a N2 atmosphere with regard to Cd-contaminated soil remediation. A pot experiment with lettuce (Lactuca sativa) was conducted to investigate the relative soil remediation effects of these biochars. The soil used for the pot experiment was spiked with 20 mg kg−1 Cd and amended with 5% of a biochar before sowing. Through these research works, some important results were obtained as follows: (1) applying biochar treated by pyrolysis under a CO2 atmosphere can obtain the best remediation effect of Cd-contaminated soil that the content of cadmium in the lettuce roots, stems, and leaves was reduced 67, 62, and 63%, respectively; (2) the magnetic biochar aggregation for the soil is weak, so the heavy metal cadmium in the soil could not be immobilized well by the magnetic biochar; (3) The remediation mechanism of novel biochars is that biochar includes a large number of organic functional groups (−C–OH, −C=O, COO−) that can act in a complexing reaction with heavy metal Cd(II) and the inorganic salt ions (Si, S, Cl, etc.) that can combine with cadmium and generate a stable combination.

Zhongxin Tan

Papers

Mechanism of negative surface charge formation on biochar and its effect on the fixation of soil Cd

Contributions and mechanisms of components in modified biochar to adsorb cadmium in aqueous solution.

Migration and Transformation Mechanisms of Nutrient Elements (N, P, K) within Biochar in Straw–Biochar–Soil–Plant Systems: A Review

Morphology, pore size distribution, and nutrient characteristics in biochars under different pyrolysis temperatures and atmospheres

Study of the mechanism of remediation of Cd-contaminated soil by novel biochars.