With the development of livestock husbandry, a large amount of copper (Cu) and arsenic (As) ions are being released into water and soil with swine urine, because Cu(II) and As(III) are commonly added into fodder to promote the growth of swine. Cu and As ions are easily absorbed by crops, and then accumulate in human body when the crops are consumed, resulting in severely harmful effects on health. This is one of the key problems that limit the sustainable development of livestock husbandry and agriculture. Therefore, it is imperative to develop a new technology to remediate Cu/As-contaminated water, soil, and swine urine.

Recently, a team led by Prof. WU Zhengyan from the Institute of Intelligent Machines of the Hefei institutes of physical science managed to develop a nanocomposite to removal Cu(II) and As(III) simultaneously. They synthesized the nanocomposite using Fe₃O₄ microspheres and ZIF-8 through a coprecipitation method, and named the obtained nano system as FZ.

In this research, scientists investigated the removal efficiency of FZ on Cu(II) and trivalent arsenic (As(III)) in water under different conditions to obtain the optimal FZ named as FZ4.

Then, they studied the removal performance of FZ4 on Cu(II) and As(III) in swine urine aqueous solution and soil. The interactions among FZ4, Cu, and As were analyzed to reveal the mechanism on Cu(II) and As(III) removal. Additionally, pot experiments were conducted to prove the removal performance of FZ4 for Cu and As.

"It turns out that FZ4 could effectively reduce the uptake of Cu and As by zebrafish and water spinach," said WU Zhengyan, lead author of the study.

This work provides a method to remove Cu(II) and As(III) simultaneously in water, soil, and swine urine, which may have a high application value in reducing Cu(II) and As(III) pollution.

This research was supported by the Science and Technology Service Program of the Chinese Academy of Sciences, the National Key R&D Program of China, the Key R&D Program of Ningxia Province, the National Natural Science Foundation of China, and the Fundamental Research Funds for the Central Universities.

Schematic illustration of the mechanism. (Image by WU Qingchuan)