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 (LDPEoxo) sheets and lignocellulosic biomass (LCB), were assembled two 0.75 L microcosm systems in vertical (VMS) and horizontal (HMS) position. The pre-treated sheets with luminescent O2 plasma discharges were mixed with pine bark, hydrolyzed brewer's yeast and paper napkin fragments and incubated for 135 days at 20 ± 1.0 °C in the presence of the fungus. With the co-transformation residues, biochar (BC) was produced at 300 ± 1.0 °C (BC300) for 1 h, then used to carry out adsorption studies, using the malachite green dye (MG) at pH 4.0, 7.0 and 9.0 ± 0.2. 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 = 0.00824) and for VMS 74.45% (p = 0.00219), concerning the pristine. Plastic roughness in VMS was higher (26%) concerning the control. Throughout the 135 days, there were fungal growth and consequently laccase (Lac), manganese peroxidase (MnP) and lignin peroxidase (LiP) activities. During the first 75 days, CO2 production increased to 4.78 ± 0.01 and 4.98 ± 0.01 mg g-1 for HMS and VMS, respectively. In MG adsorption studies, the highest amount of the colourant adsorbed at both pH 4.0 and 7.0 ± 0.2. 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.
ABSTRACT
Liquid waste from biological stains is considered non-domestic wastewater difficult to treat, generating high environmental impact. Therefore, the objective of this work was to carry out secondary and tertiary treatment of these effluents at a pilot scale, using a fungal/bacterial consortium followed by Chorella sp., for 15 days. In addition, to obtain an adsorbent material for Malachite Green dye removal, sludge generated in the plant and pine bark co-pyrolysis was performed. For microalgae isolation and selection of the Chlorophyceae class, Chlorococcales order, and Chorella sp. genus Winogradsky columns were employed. After 15 days of pilot plant treatment, removal percentages of 91 ± 2%, 90 ± 4% and 17 ± 2% were obtained for Colour Units, Chemical Oxygen Demand and Nitrates, respectively. Two types of class II biochar (BC500 and BC700) and one of class III (BC300) were produced. The highest value for Fixed carbon (FC) was obtained at 300 °C (27.3 ± 3%), decreasing as the temperature increased by 25.9 ± 5% and 24.8 ± 2%, for BC500 and BC700, respectively. Biochar yield was 62.1 ± 3%, 46.3 ± 4% and 31.6 ± 3% for BC300, BC500 and BC700, respectively. Finally, BC500 and BC700 biochar efficiently adsorbed Malachite Green obtaining qe values of 0.290 ± 0.032, 0.281 ± 0.015, 0.186 ± 0.009 and 0.191 ± 0.012 mg g-1 at pH values of 4.0 and 8.0 ± 0.2, respectively. Pseudo-second order model demonstrated a chemical adsorption took place, which was influenced by pH. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02780-1.
