Carbon Nanotubes/Polydopamine/ZSM-5 Composite Soil Conditioner with Good Controlled Release and Adsorption Properties

Currently, the excessive application of fertilizers and the random discharge of waste water, waste gas, and residues have led to more and more serious soil pollution problems. Zeolite is the most promising material for preparing a green and environmentally friendly soil conditioner. Herein, the carbon nanotubes/polydopamine/ZSM-5 composite soil conditioner was prepared by a facile two-step method, and it was used to release fulvic acid and adsorb methylene blue to improve the environment. The cumulative release rate of the composite soil conditioner was 52% within 430 h for fulvic acid, which had a good sustained release effect and could be sustained-released in different acid-based surroundings. In addition, it showed a good adsorption capacity of methylene blue, and it is about 80.02 mg/g which was about six times higher than that of ZSM-5. It was beneficial for the adsorption of methylene blue in a neutral environment. Finally, it could promote the growth of brassica chinensis and maize, and the promotion effect was 60 and 35%, respectively. Therefore, the carbon nanotubes/polydopamine/ZSM-5 composite soil conditioner is a green and efficient material, which provides a new strategy to solve the problem of soil pollution.