Combination of Celluclast and Viscozyme improves enzymatic hydrolysis of residual cellulose casings: process optimization and scale-up

Enzymatic hydrolysis of the organic fraction of municipal solid waste: Optimization and valorization of the solid fraction for Bacillus thuringiensis biopesticide production through solid-state fermentation

To reach a more sustainable society, the implementation of a circular economy perspective in municipal waste management becomes essential. In this work, the enzymatic hydrolysis of source-separated organic fraction of municipal solid waste (OFMSW) has been optimized as a sugar-releasing step. A liquid sugar concentrate, with a maximum reducing sugar concentration of 50.56 g L^-1, and a solid hydrolyzed fraction were obtained. The effect of the harshness of the hydrolysis conditions was evaluated on the performance of the resulting solid fraction as a substrate for Bacillus thuringiensis biopesticide production through solid-state fermentation. A production of 3.9 × 10⁸ viable cells g^-1 dry matter with a 33% sporulation ratio was achieved for milder hydrolysis conditions, highlighting the potential of the solid fraction of hydrolysis as a substrate of SSF processes. The proposed valorization pathway for the OFMSW results in a sugar concentrate with potential for fermentative processes and a fermented solid containing biopesticides from Bacillus thuringiensis.

Novel sorbent shows promising financial results on P recovery from sludge water

For several decades, researchers have been struggling to obtain minimum phosphorus (P) capture costs to meet the parameters for discharging wastewater into the watercourse. Findings from ongoing practices suggest that the Modified University of Cape Town process is currently the cheapest P capture method in the USA, whereas struvite precipitation seems to be the most cost effective method in the rest of the developed world. P sorption via biochars is becoming widespread in developing countries because this technique allows for the turning of voluminous biowaste into fertilizer with soil improving properties. Nevertheless, the reliability of this technology fluctuates throughout the year according to biowaste characteristics. For the first time, it has been proposed to use broken cellulose casings, which are readily available in increasing quantities worldwide. The sorbent obtained was subsequently activated by calcium chloride (CaCl₂), whose cost is irrelevant as it would be used for agronomical purposes anyway. Pilot scale experiments show that this novel sorbent is capable of capturing 31.8 kg P t^-1 from sludge water that contains 52.5 mg of extractable P L^-1. More importantly, it was reported that the novel sorbent captures P, mostly in calcium phosphates (CaP) forms (191.5 g CaP t^-1), which are the most valuable for plant nutrition. Enough evidence was obtained to claim that the ongoing technological race to meet the P discharge standards at the lowest cost possible should also reflect the agronomic value of P to plant nutrition to increase its competitiveness.