SinoGreenTech Academic Portal
ZZ
Verified CAS / Academic Author2 Decoded Studies

Prof. ZHENG Zhiyong

School of Environment and Ecology, Jiangnan University, Wuxi 214122, China

Co-Affiliations:Xizang University / Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences

Research Publications & English Decoded Briefs

Showing 2 publications
Chinese Journal of Environmental Engineering2026DOI: 10.12030/j.cjee.202506031

Preparation and Engineering Scale-Up of Cyanobacteria-Based Columnar Activated Carbon

The production of activated carbon from waste biomass such as cyanobacteria from Lake Taihu represents a promising resource utilization route. However, existing studies are mostly confined to laboratory scale, and the gap between laboratory processes and industrial production hinders the evaluation of technical feasibility and economic viability. This study optimized the process for producing cyanobacteria-based columnar activated carbon by co-processing cyanobacteria with garden waste (sawdust), and validated the process on an engineering-scale production line with a daily capacity of 5 t of raw materials. Economic feasibility was also assessed. Results showed that the optimized activated carbon exhibited a particle strength of 91.3% and a specific surface area of 571.44 m2·g−1. The engineering-scale line processed 5 t of raw materials daily, yielding approximately 1.18 t of activated carbon with stable quality: strength of 94.3% and specific surface area of 471.42 m2·g−1, featuring a microporous-dominant structure with coexisting micropores and mesopores. Cost analysis indicated a production cost of 3,595.65 CNY per ton of activated carbon, demonstrating favorable economic benefits. This work provides a basis for larger-scale production and application of cyanobacteria-based activated carbon.

Journal of Environmental Engineering Technology2026DOI: 10.13205/j.hjgc.202607016

Preparation of Biochar from Co-pyrolysis of Napier Grass and Food Waste Digestate for Pb²⁺ Removal from Wastewater

Lead (Pb) is a highly toxic heavy metal that poses severe risks to environmental and human health, particularly affecting children's neurological development. This study investigates the adsorption performance and mechanisms of biochars derived from pyrolysis of Napier grass (Pennisetum purpureum), food waste digestate, and their mixtures for Pb²⁺ removal from aqueous solutions. Biochars were prepared at different mass ratios, and the optimal material (HP3SD1-B, Napier grass:digestate = 3:1) exhibited a maximum equilibrium adsorption capacity of 306.45 mg/g and a theoretical Langmuir maximum capacity of 447.62 mg/g, significantly outperforming pure digestate biochar and lower-ratio blends. Adsorption kinetics followed a three-stage profile: rapid liquid-film diffusion (0–180 min), intraparticle diffusion (180–360 min), and equilibrium at 360 min. The adsorption process was well described by the pseudo-second-order kinetic model (R² > 0.99) and the Langmuir isotherm, indicating monolayer chemisorption. Characterization via FTIR, XPS, SEM-EDS, and Zeta potential revealed that Pb²⁺ immobilization occurs primarily through surface precipitation (Pb₃(CO₃)₂(OH)₂ and PbO), complexation with hydroxyl, ether, and aromatic C=C groups, and auxiliary mechanisms including electrostatic attraction and K⁺/Mg²⁺ ion exchange. Optimal adsorption occurred at pH 6, correlating with the point of zero charge (PZC ≈ 2). This study demonstrates that co-pyrolysis of agricultural and organic solid wastes offers a cost-effective, high-performance biochar for heavy metal remediation, aligning with circular economy principles.