Efficient Removal of Cu(II), Zn(II), and Cd(II) from Aqueous Solutions by a Mineral-Rich Biochar Derived from a Spent Mushroom (Agaricus bisporus) Substrate.

Guosheng Zhang,Long Su,Kokyo Oh,Haibo Zhang,Yuan Luo,Hongyan Cheng,Na Liu

doi:10.3390/ma14010035

Guosheng Zhang, Long Su + Show 5 more

Open Access

https://doi.org/10.3390/ma14010035

Copy DOI

Journal: Materials	Publication Date: Dec 23, 2020
Citations: 14	License type: CC BY 4.0

Affiliation: Shanxi Agricultural University

Abstract

This study evaluated the novel application of a mineral-rich biochar derived from a spent Agaricus bisporus substrate (SAS). Biochars with various pyrolysis temperatures (350–750 °C) were used to remove Cu(II), Zn(II), and Cd(II) from aqueous solutions. The adsorption characteristics and removal mechanisms of the biochars were investigated. The adsorption kinetics and isotherm data were fitted well by pseudo-second-order and Freundlich models. The Langmuir maximum removal capacity (Qmax) values of Cu(II), Zn(II), and Cd(II) were ordered as SAS750 > SAS350 > SAS550, and the Qmax values of SAS750 were 68.1, 55.2, and 64.8 mg·g−1, respectively. Overall, the removal mechanisms of biochar at a low production temperature (350 °C) to Cu(II), Zn(II), and Cd(II) were mainly via ion exchange (54.0, 56.0, and 43.0%), and at a moderate production temperature (550 °C), removal mechanisms were mainly via coordination with π electrons (38.3, 45.9, and 55.0%), while mineral precipitation (65.2, 44.4, and 76.3%, respectively) was the dominant mechanism at a high produced temperature (750 °C). The variation of the mutual effect of minerals and heavy metals was the predominant factor in the sorption mechanism of mineral precipitation and ion exchange. The results demonstrated that spent Agaricus bisporus substrate biochar is a potential candidate for the efficient removal of heavy metals, which provides a utilization route for spent mushroom substrates.

Highlights

IntroductionReceived: 2 December 2020Accepted: 21 December 2020Published: 23 December 2020Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.license (https://creativecommons.org/licenses/by/4.0/).Edible fungi are organic, green, and healthy foods
Received: 2 December 2020Accepted: 21 December 2020Published: 23 December 2020Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.license.Edible fungi are organic, green, and healthy foods
Compared with other biochar feedstocks, spent Agaricus bisporus substrates are complex mixtures that are derived from edible fungal cultivation

Summary

Introduction

Received: 2 December 2020Accepted: 21 December 2020Published: 23 December 2020Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.license (https://creativecommons.org/licenses/by/4.0/).Edible fungi are organic, green, and healthy foods. Approximately 5 kg of spent mushroom substrate is generated during the production process of 1 kg of edible fungi [1,2]. In 2018, approximately 70 million tons of edible fungi were produced in China; a large amount (approximately 350 million tons) of spent mushroom substrate had to be treated and utilized. Various methods have been proposed for the reuse of spent mushroom substrates, such as conventional treatment methods, e.g., as compost [3,4] or feed [5]; these methods are only suitable for treating small amounts of substrate. Most spent mushroom substrates are not effectively disposed of and are randomly stacked or burned in open air [6]. The development of an economical and environmentally friendly treatment method for spent mushroom substrates is necessary

Methods

Results

Conclusion