Biochar with enhanced performance prepared from bio-regulated lignocellulose for efficient removal of organic pollutants from wastewater

This work presented a novelty method for preparing lignocellulosic materials with reinforced performances, that is, the lignocellulose of corn straw was bio-regulated into cellulose, hemicellulose, and lignin via three types of microorganisms (Aspergillus niger, Myrothecium verrucaria, Trichoderma reesei) with cross treatment. Three different types of biochar were then prepared by the carbonization and combined alkali activation processes. The results showed that the great quantity of micro/mesopores endowed biochars ultra-high specific surface areas up to 2881, 2986, and 2878 m2 g-1. Biochars exhibited ultra-high maximum adsorption capacities for crystal violet (CV) and tetracycline hydrochloride (TC), which was higher than that of most adsorbents including the corn straw-based carbon and multi-walled carbon nanotube. After five cycles, the samples maintained a removal rate of over 70% for CV and over 60% for TC, proving their good potential for recycling. This study showed that the bio-regulation of lignocellulose was not only an effective method to develop materials with enhanced adsorption performances, but also provided a feasible idea for the comprehensive utilization of lignocellulose.