Evaluation of two microcosm systems for co-treatment of LDPEoxo and lignocellulosic biomass for biochar production

Abstract

Background The co-transformation of solid waste of natural and anthropogenic origin can be carried out through solid-state-fermentation systems to obtain bio-products with higher added value and lower environmental impact. Methods To evaluate the effect of Pleurotus ostreatus on co-transformation of oxo-degradable low-density polyethylene (LDPE oxo ) sheets and lignocellulosic biomass (LCB), were assembled two 0.75\u2009L microcosm systems in vertical (VMS) and horizontal (HMS) position. The pre-treated sheets with luminescent O 2 plasma discharges were mixed with pine bark, hydrolyzed brewer’s yeast and paper napkin fragments and incubated for 135\u2009days at 20\u2009±\u20091.0\u2009°C in the presence of the fungus. With the co-transformation residues, biochar (BC) was produced at 300\u2009±\u20091.0\u2009°C (BC300) for 1 h, then used to carry out adsorption studies, using the malachite green dye (MG) at pH\u20094.0, 7.0 and 9.0\u2009±\u20090.2. Finally, the biochar was the substrate for the germination of carnation seeds ( Dianthus caryophyllus ) and Ray-grass ( Lolium sp.) in vitro. Results For HMS, the decrease in static contact angle (SCA) was 63.63% ( p \u2009=\u20090.00824) and for VMS 74.45% ( p \u2009=\u20090.00219), concerning the pristine. Plastic roughness in VMS was higher (26%) concerning the control. Throughout the 135\u2009days, there were fungal growth and consequently laccase (Lac), manganese peroxidase (MnP) and lignin peroxidase (LiP) activities. During the first 75\u2009days, CO 2 production increased to 4.78\u2009±\u20090.01 and 4.98\u2009±\u20090.01\u2009mg\u2009g-1 for HMS and VMS, respectively. In MG adsorption studies, the highest amount of the colourant adsorbed at both pH\u20094.0 and 7.0\u2009±\u20090.2. Conclusions Finally, the biochar or the biochar enriched with low concentrations of plant growth-promoting microorganisms and inorganic fertilizer favours the germination of Dianthus caryophyllus and Lolium sp., seeds.