Enhanced biodegradation of 2, 4-dichlorophenol in packed bed biofilm reactor by impregnation of polyurethane foam with Fe3O4 nanoparticles: Bio-kinetics, process optimization, performance evaluation and toxicity assessment.

In this work, an effort has been made to enhance the efficacy of biological process for the effective degradation of 2, 4-dichlorophenol (2, 4-DCP) from wastewater. The polyurethane foam was modified with Fe3O4 nanoparticles and combined with polyvinyl alcohol, sodium alginate, and bacterial consortium for biodegradation of 2, 4-DCP in a packed bed biofilm reactor. The maximum removal efficiency of 2, 4-DCP chemical oxygen demand, and total organic carbon were found to be 92.51 ± 0.83 %, 86.85 ± 1.32, and 91.78 ± 1.24 %, respectively, in 4 days and 100 mg L-1 of 2, 4-DCP concentration at an influent loading rate of 2 mg L-1h-1 and hydraulic retention time of 50 h. Packed bed biofilm reactor was effective for up to four cycles to remove 2, 4-DCP. Growth inhibition kinetics were evaluated using the Edward model, yielding maximum growth rate of 0.45 day-1, inhibition constant of 110.6 mg L-1, and saturation constant of 62.3 mg L-1.

Determination of thermal degradation behavior and kinetics parameters of chemically modified sun hemp biomass.

Sun hemp fibers are natural fibers obtained from plants grown in India and nearby countries. It is lignocellulosic biomass having the complex structure of hemicelluloses, cellulose and lignin. Chemical treatment of natural fibers is in practice to enhance the properties being used as reinforcement. Alkaline-treated fiber was sampled and thermal stability along with kinetic parameters was assessed with thermo gravimetric data at heating rates 10, 20 and 30 °C/min using four model-free methods Kissinger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa (FWO), Friedman (FM), Starink (STAR) along with Distributed activation energy model (DAEM) to calculate pre-exponential factor. The calculated activation energy Ea by these model-free methods were in the range of 93.3-104.8 kJ/mol and pre-exponential factor (A) was observed between the range 46.6 x103-90.5 x106/min by the DAEM method. The standard deviation (σ) calculated from average activation energy using all four methods was 4.5 kJ/mol, which showed the consistency in the methods employed to determine the activation energy of sun hemp.

Barriers in biogas production from the organic fraction of municipal solid waste: A circular bioeconomy perspective.

Biogas-based circular bioeconomy can provide a long-term way out of the organic fraction of municipal solid waste. The barriers to biogas production are obstructing the growth of the biogas-based circular bioeconomy. This study provides a comprehensive analysis of the barriers to biogas in developing countries for the wider implementation of biogastechnology. Twenty barriers are identified and categorized into technical, logistical, institutional, and social dimensions. The analytical hierarchy process is applied to rank the barriers. The result of barrier ranking shows that the lack of appropriate segregation facilities is the most crucial barrier, followed by waste characteristics variation, and inconsistent supply. This study will provide an outline for rational decision-making in the sustainable organic fraction of municipal waste management.

Role and significance of lytic polysaccharide monooxygenases (LPMOs) in lignocellulose deconstruction.

Lytic polysaccharide monooxygenases (LPMOs) emerged a decade ago and have been described as biomass deconstruction boosters as they play an extremely important role in unravelling the enzymatic biomass hydrolysis scheme. These are oxidative enzymes requiring partners to donate electrons during catalytic action on cellulose backbone. Commercial cellulase preparations are mostly from the robust fungal sources, hence LPMOs from fungi (AA9) have been discussed. Characterisation of LPMOs suffers due to multiple complications which has been discussed and challenges in detection of LPMOs in secretomes has also been highlighted. This review focuses on the significance of LPMOs on biomass hydrolysis due to which it has become a key component of cellulolytic cocktail available commercially for biomass deconstruction and its routine analysis challenge has also been discussed. It has also outlined a few key points that help in expressing catalytic active recombinant AA9 LPMOs.

Resource recovery and biorefinery potential of apple orchard waste in the circular bioeconomy.

In this review investigate the apple orchard waste (AOW) is potential organic resources to produce multi-product and there sustainable interventions with biorefineries approaches to assesses the apple farm industrial bioeconomy. The thermochemical and biological processes like anaerobic digestion, composting and , etc., that generate distinctive products like bio-chemicals, biofuels, biofertilizers, animal feed and biomaterial, etc can be employed for AOW valorization. Integrating these processes can enhanced the yield and resource recovery sustainably. Thus, employing biorefinery approaches with allied different methods can link to the progression of circular bioeconomy. This review article mainly focused on the different biological processes and thermochemical that can be occupied for the production of waste to-energy and multi-bio-product in a series of reaction based on sustainability. Therefore, the biorefinery for AOW move towards identification of the serious of the reaction with each individual thermochemical and biological processes for the conversion of one-dimensional providences to circular bioeconomy.

Hydrothermal liquefaction of rice husk and cow dung in Mixed-Bed-Rotating Pyrolyzer and application of biochar for dye removal.

This work studied the hydrothermal liquefaction of rice husk (RH) and cow dung (CD) for the production of biochar from RH and CD and use of that biochar for the removal of dye from textile industry effluent. These biomasses were subjected to fast pyrolysis (500 °C), which yielded biochar (22.8 and 29.8%) and bio-oil (60.4 and 57.3%) from RH and CD, respectively. Biochar was characterized based on spectroscopy Fourier Transform Infrared Spectroscopy (FTIR) and morphological studies like Scanning Electron Microscope (SEM) and SEM-EDS. Further, bio-oil samples were characterized by GC-MS into saturated and polyunsaturated fatty acids, carboxylic acids, phenolics and aromatic hydrocarbons. The removal efficiencies of the Congo red dye from prepared biochar in a batch experiment were 66.8-96.9%(RH) and 68.9-98.8%(CD). The adsorption isotherms for Langmuir (R2 = 0.977 and 0.902) and Freundlich (R2 0.842 and 0.883) were calculated for RH and CD biochar, respectively.

Application of Arjuna (Terminalia arjuna) seed biochar in hybrid treatment system for the bioremediation of Congo red dye.

In the present study, a hybrid treatment system (biological and ozonation) was developed and used in the decolorization of Congo red (CR) dye. The biological treatment was performed in packed bed bioreactor (PBBR) containing Arjuna (Terminalia Arjuna) seeds biochar immobilized with Providencia stuartii, whereas ozonation was carried out in an ozone reactor. The process variables such as temperature, process time, and inoculum size were optimized and found to be 30 °C, 2 48 h, and 3 × 105 CFU/mL, respectively with 92.0 ± 5.0% of dye decolorization. Furthermore, biologically treated effluent was subject to ozone treatment for the decolorization of the remaining CR dye. The hybrid approach reveals almost complete decolorization of Congo red (CR) dye. The kinetic study of microbial growth was examined by Monod model. In addition, the cost analysis estimation for the removal of CR dye was done, and removal per liter was found to be economic.