A Chinese study team reported they managed to develop a new acid soil remediation agent (ASRA) which use a nano composite composed of nanoclay, biochar and so on.

This new-developed approach could remove the existing barriers in ASRA’s practical applications, reported the team led by WU Zhengyan in Institute of Technical Biology and Agriculture Engineering, Hefei Institutes of Physical Science of the Chinese Academy of Sciences.

Acid soil (AS), which occupies approximately 30% of the world's ice-free land, has become a common issue in agriculture all over the world. This soil commonly leads to phosphorus deficiency, reduced productivity, and ionization of heavy metals that can be absorbed by crops and then human beings, causing a series of diseases.

Therefore, it is significant to develop a new kind of remediation agent which can not only improve the pH of soil, but also immobilize the heavy metal in AS.

The ASRA possessed a porous nano-networks structure and high specific surface area that could efficiently control the leaching loss of cations and reduce the move and activity of Cr(VI) in AS.

Meanwhile, Cr(VI) could be immobilized by ASRA via hydrogen bonds between -OH of nanoclay and Cr-O of CaCrO₄.

Besides, it was shown that the ASRA was effective to increase the pH of the AS in both lateral and vertical directions. Pot experiment points to that ASRA possessed a high ability to remediate AS and facilitate the growth of corns in AS.

This work provides a low cost, high efficiency, environmentally friendly, and facile approach to remediate Cr(VI)-contaminated AS.

This approach titled Remediation of Cr(VI)-contaminated acid soil using a nano composite was published in ACS Sustainable Chemistry & Engineering.

This research was supported by the National Natural Science Foundation of China, the Key Program of Chinese Academy of Sciences, the Youth Innovation Promotion Association of Chinese Academy of Sciences, the Grant of the President Foundation of Hefei Institutes of Physical Science of Chinese Academy of Sciences, and the Science and Technology Service Programs of Chinese Academy of Sciences.

Schematic diagram of the mechanism of ASRA for remediating Cr(VI)-contaminatedacid soil. (Image by WANG Dongfang)