The aim of this study was to evaluate the impact of cellulase (C) on the biological activity of chitosan/hydroxypropyl methylcellulose (CH/HPMC) film-forming hydrosols. The hydrolytic activity of cellulase in two concentrations (0.05% and 0.1%) was verified by determination of the progress of polysaccharide hydrolysis, based on viscosity measurement and reducing sugar-ends assay. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging effect, the ferric reducing antioxidant power (FRAP), and microbial reduction of Pseudomonas fluorescens, Yersinia enterocolitica, Bacillus cereus, and Staphylococcus aureus were studied. During the first 3 h of reaction, relative reducing sugar concentration increased progressively, and viscosity decreased rapidly. With increasing amount of enzyme from 0.05% to 0.1%, the reducing sugar concentration increased, and the viscosity decreased significantly. The scavenging effect of film-forming solutions was improved from 7.6% at time 0 and without enzyme to 52.1% for 0.1% cellulase after 20 h of reaction. A significant effect of cellulase addition and reaction time on antioxidant power of the tested film-forming solutions was also reported. Film-forming hydrosols with cellulase exhibited a bacteriostatic effect on all tested bacteria, causing a total reduction.
Peat is the main type of peloid used in Polish cosmetic/healing spa facilities. Depending on treatment and origin, peat waste can be contaminated microbiologically, and as a result, it must be incinerated in medical waste incineration plants without energy recovery (local law). Such a situation leads to peat waste management costs increase. Therefore, in this work, we checked the possibility of peat waste upcycling to carbonized solid fuel (CSF) using torrefaction. Torrefaction is a thermal treatment process that removes microbiological contamination and improves the fuel properties of peat waste. In this work, the torrefaction conditions (temperature and time) on CSF quality were tested. Parallelly, peat decomposition kinetics using TGA and torrefaction kinetics with lifetime prediction using macro-TGA were determined. Furthermore, torrefaction theoretical mass and energy balance were determined. The results were compared with reference material (wood), and as a result, obtained data can be used to adjust currently used wood torrefaction technologies for peat torrefaction. The results show that torrefaction improves the high heating value of peat waste from 19.0 to 21.3 MJ × kg−1, peat main decomposition takes place at 200–550 °C following second reaction order (n = 2), with an activation energy of 33.34 kJ × mol−1, and pre-exponential factor of 4.40 × 10−1 s−1. Moreover, differential scanning calorimetry analysis revealed that peat torrefaction required slightly more energy than wood torrefaction, and macro-TGA showed that peat torrefaction has lower torrefaction constant reaction rates (k) than wood 1.05 × 10−5–3.15 × 10−5 vs. 1.43 × 10−5–7.25 × 10−5 s−1.
Peat is the main type of peloid used in Polish cosmetic/healing spa facilities. Depending on treatment and origin, peat waste can be contaminated microbiologically, and as a result, it must be incinerated in medical waste incineration plants without energy recovery (local law). Such a situation leads to peat waste management costs increase. Therefore, in this work, we checked the possibility of peat waste upcycling to carbonized solid fuel (CSF) using torrefaction. Torrefaction is a thermal treatment process that removes microbiological contamination and improves the fuel properties of peat waste. In this work, the torrefaction conditions (temperature and time) on CSF quality were tested. Parallelly, peat decomposition kinetics using TGA and torrefaction kinetics with lifetime prediction using macro-TGA were determined. Furthermore, torrefaction theoretical mass and energy balance were determined. The results were compared with reference material (wood), and as a result, obtained data can be used to adjust currently used wood torrefaction technologies for peat torrefaction. The results show that torrefaction improves the high heating value of peat waste from 19.0 to 21.3 MJ × kg−1, peat main decomposition takes place at 200–550 °C following second reaction order (n = 2), with an activation energy of 33.34 kJ × mol−1, and pre-exponential factor of 4.40 × 10−1 s−1. Moreover, differential scanning calorimetry analysis revealed that peat torrefaction required slightly more energy than wood torrefaction, and macro-TGA showed that peat torrefaction has lower torrefaction constant reaction rates (k) than wood 1.05 × 10−5–3.15 × 10−5 vs. 1.43 × 10−5–7.25 × 10−5 s−1.
There are insufficient data for the development of process design criteria for constructed wetlands systems based on submerged plants as a major treatment agent. The aim of the study was to evaluate the oxygen transfer capacity (OTC) of E. densa, in relation to wet plants’ mass (w.m.), and the influence of E. densa on the oxygen concentration and contaminants’ removal efficiency from municipal wastewater. The obtained oxygen concentration and temperature data allowed to calculate the OTC values (mg O2·L−1·h−1), which had been related to wet plants’ mass unit (mg O2·L−1·h−1·g w.m.−1). The efficiency of wastewater treatment was determined in relation to initial wastewater content in the mixture of wastewater and tap water (0%, 25%, 50%, and 100%) during 3 days of the experiment duration. The simulation of day and night conditions was done by artificial lighting. Before and after finishing the second experiment, the COD, Ntotal, and P-PO4 concentration were analyzed in wastewater solutions. The OTC ranged from 3.19 to 8.34 (mgO2·L−1·h−1·g w.m.−1), and the increase of OTC value was related to the increase of wet plant’s mass. The research showed that E. densa affected positively on the wastewater treatment efficiency, and the highest efficiency was achieved in 25% wastewater solution: 43.6% for COD, 52.9% for Ntotal, 14.9% for P-PO4.