Abstract
AbstractThe disposal of residues while manufacturing Chinese medicine has always been an issue that concerns pharmaceutical factories. Phanerochaete chrysosporium was inoculated into the residues of Magnolia officinalis for solid-phase fermentation to enzymatically hydrolyze the lignin in the residues and thus to improve the efficiency of removal of the copper ions from residues for the utilization of residues from Chinese medicine. With the increase in activities of lignin-degrading enzymes, especially during the fermentation days 6 to 9, the removal rate of copper ions using M. officinalis residues increased dramatically. The rate of removal reached the maximum on the 14th day and was 3.15 times higher than the initial value. The rate of adsorption of copper ions on the fermentation-modified M. officinalis residues followed the pseudo-second-order kinetics. The adsorption isotherms were consistent with the Freundlich models. The adsorption enthalpy was positive, indicating that it was endothermic and elevation in temperature was favorable to this adsorption process. The adsorption free energy was negative, implying the spontaneity of the process. The copper ions adsorbed could be effectively recovered using 0.2 M hydrochloric acid solution. After five successive cycles of adsorption-regeneration, the fermentation-modified M. officinalis residues exhibited a stable adsorption capacity and greater reusability. The M. officinalis residues fermented with P. chrysosporium are low-cost and environmentally friendly copper ions adsorbent, and this preparation technique realizes the optimum utilization of Chinese medicine residues.
Highlights
IntroductionDue to the booming industries for metal smelting, electroplating, printed circuit board, and others, the amount of wastewater discharge containing copper ions has been increased substantially, resulting in the pollution of a large amount of soil and surface water and jeopardizing the environment [1]
Clean water resources are requisite for the ecological environment
The copper ions adsorbed could be recovered with 0.2 M hydrochloric acid solution at 25°C and 150 r/min shaking for 2 hours for desorption, the regenerated adsorbent was used in the adsorption experiment
Summary
Due to the booming industries for metal smelting, electroplating, printed circuit board, and others, the amount of wastewater discharge containing copper ions has been increased substantially, resulting in the pollution of a large amount of soil and surface water and jeopardizing the environment [1]. The traditional copper-removing methods include coagulation, precipitation, membrane separation, extraction, evaporation [4], which require equipments, high cost, high energy, and toxic chemicals. While these approaches are mainly applied to treat concentrated copper-containing wastewater, adsorption is a common and easy method to treat dilute wastewater [5]. The cost of chemically modified adsorbents is usually high, considering the large volumes of dilute copper-containing wastewater. It is necessary to develop cheaper and eco-friendly alternative adsorbents
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
