Zn2+ modified activated carbon from spent mushroom substrate for organic wastewater treatment

In this work, a physical adsorption strategy including three steps of "turning waste into treasure-removal of pollutants-adsorption mechanism" have been provided to solve the environmental problems caused by spent mushroom substrate and organic pollution simultaneously. A series of environment-friendly Zn2+ modified activated carbon (AC) with adequate adsorption capacity are prepared by using spent mushroom substrate as raw material. X-Ray Diffraction results indicate weak graphitization of Zn2+ modified AC sample during the calcination process. FTIR results indicate that the AC adsorbents are inevitably entailed with abundant surface functional groups. Zn2+ modified AC calcinated at 600 degrees C (Zn-AC-600) has the bigger BET surface area of 450 m(2).g(-1) and excellent adsorption property, it can remove about 95, 75, and 88 % of Rhodamine B, Amoxicillin and Cefixime after 120 min adsorption process. While the maximal adsorption capacity q(max) for Rhodamine B, Amoxicillin and Cefixime towards Zn-AC-600 sample is about 202, 123, and 130 mg.g(-1), respectively. The adsorption process of all pollutants is found to match well with the pseudo-second-order kinetics. Zeta potential measurements reveal that Zn-AC-600 is negatively charged (-23.5 mV), which can absorb Rhodamine B, Amoxicillin, and Cefixime by electrostatic attraction. This work may provide an effective strategy toward beneficial recycling of spent mushroom substrate wastes and remove pollutants from water.