43 research outputs found
Fermentative Hydrogen Production from Indigenous Mesophilic Strain Bacillus Anthracis PUNAJAN 1 Newly Isolated from Palm Oil Mill Effluent
In the present study, a new mesophilic bacterial strain, identified as Bacillus anthracis strain PUNAJAN 1 was isolated from palm oil mill effluent (POME) sludge, and tested for its hydrogen production ability. Effect of physico-chemical factors such as temperature, initial pH, nitrogen source and carbon sources were investigated in order to determine the optimal conditions for hydrogen production. The maximum hydrogen yield of 2.42 mol H2/mol mannose was obtained at 35 °C and initial pH of 6.5. Yeast and mannose were used as the main carbon and nitrogen sources respectively in the course of the hydrogen production. Apart from synthetic substrate, specific hydrogen production potentials of the strain using POME was calculated and found to be 236 ml H2/g chemical oxygen demand (COD). The findings of this study demonstrate that the indigenous strain PUNAJAN 1 could be a potential candidate for hydrogen using POME as substrate
High methoxyl pectin extracts from hylocereus polyrhizus's peels: Extraction kinetics and thermodynamic studies
The effect of physicochemical treatment on pectin yield, degree of esterification, along with the kinetics and thermodynamics characteristics was investigated in the present study. Several extraction parameters were observed to have impacted the yield and degree of esterification significantly, and the best extraction condition was as follows: agitation rate of 250 rpm, temperature of 70 °C, extraction time of 120 min, pH 2, and liquid to solid ratio of 10 v/w which has resulted in 28.20% of pectin yield, with DE (degree of esterification) of 57.00%. A theoretical model which describes the extractability, dissolution and degradation rate of pectin to predict the maximal yield at the maximal time was established to study the extraction kinetics of pectin from HPP. The kinetic analysis from Panchev's model shows the extraction rate was found highest at LSR 10 with ymax 30.85%. The calculated activation energy for pectin dissolution and degradation was found to be 4.532 kJ/mol and 28.054 kJ/mol, respectively. The thermodynamic study has suggested that the process was endothermic, spontaneous and reversible. These results suggest that the physical and chemical treatment applied could be an efficient technique for the extraction of pectin from Hylocereus polyrhizus peels
Comparison of Process Stability in Methane Generation from Palm Oil Mill Effluent using Dairy Manure as Inoculum
The potential of methane production in a continuously stirred tank reactor (CSTR) was investigated using dairy manure as inoculum at pH 6.8 and 37 °C temperature in this study. Two identical anaerobic bioreactors namely CSTR1 and CSTR2 filled with palm oil mill effluent (POME) as a carbon source were used. CSTR1 was not added with the inoculum, while CSTR2 was added with dairy manure as inoculum. Both the reactors were allowed to run for 5 days (d) in batch condition at hydraulic retention time (HRT) 10 d. The CSTR2produced 0.85 L/d gas yield and 59% methane content compared to 0.39 L/d gas yield and 20% produced in CSTR1, respectively. A better chemical oxygen demand (COD) reduction percentage of 48% was found in CSTR2 compared to CSTR1 with 33%. The investigation showed that dairy manure as inoculum has a marked influence on the start-up period and the biogas production rate
Challenges and emerging approaches in life cycle assessment of engineered nanomaterials usage in anaerobic bioreactor
Nanotechnology has wide applications in all areas such as agriculture, the environment, and industry energy pharmaceuticals. The use of nanoparticles (NPs) is increasing, positive and negative effects in various environmental areas, including air, water, and soil, have recently been discovered. Various types of engineered NPs (ENPs) have been used in the renewable energy production system. Anaerobic digestion (AD) process is cost-effective and waste-to-energy production. Different types ENPs are applied in the AD method for improving biogas yield with suitable conditions. ENPs have their excellent performance in understanding their presence, behavior, and impact on water is critical during the AD process. This study aims to understand the consequence of ENPs on the biogas production rate in the AD system. ENPs interaction with bacteria in the AD process for increasing biogas yield rate in the AD process has been discussed. Cost-effective ENPs production, life cycle assessment, and challenges have been elaborated. Finally, the positive effect of ENPs in the AD system for enhancing biogas yield has been conclud
Bioenzyme activation preparation of Fe3O/carbon nanofibers as supercapacitor electrode materials
A new activation method for carbon-based pore expansion of composite materials was developed using the biocatalytic principle of amylase to hydrolyze cyclodextrin into small molecules of maltose and glucose. The composite carbon nanofiber mats were prepared by electrospinning with polyacrylonitrile (PAN), α-cyclodextrin, iron acetylacetonate as the iron oxide precursor, and hemp straw-based liquefied carbon as the electrospinning precursors. The α-cyclodextrin was hydrolyzed by medium-temperature α-amylase to generate pores, and a composite electrode material of carbon nanofibers with controlled iron oxide/porous structure was prepared through pre-oxidation and carbonization. Based on the morphology and structure of the prepared electrode materials and the electrochemical performance of three electrodes and two electrodes, it can be concluded that it is feasible to prepare electrochemical materials with the pore structure of carbon nanofibers by the enzyme pore enlarging method. Meanwhile, the FePCNF1 reaches 314 F g−1; at the current density 10 A g−1, over 75.6% of initial capacitance is retained as the current density improves from 1 to 10 A g−1 and also exhibits an excellent cycling performance with 62% capacitance retention after 15,000 times charge/discharge cycles
Environmental and economic life cycle assessment of biochar use in anaerobic digestion for biogas production
Due to the increasing demand for sustainable energy sources and effective management of the ever-increasing volume of organic waste, anaerobic digestion (AD) has continued to play a crucial role in biogas production in recent years. Biochar (BC) is a highly flexible material manufactured by carbonizing organic resources like biomass and trash in line with circular economy standards and “tailor-made” for certain purposes. The capacity of BC as an additive to address various well-established crucial difficulties in AD methods has been extensively studied during the last 10 years. Nevertheless, a comprehensive and credible explanation of the BC-AD link remains elusive. The life cycle analysis (LCA) of the biogas enhancement mechanism would provide a quantitative indicator of its long-term viability. The reported LCA studies of AD processes are analyzed in this chapter, showing that few systematic studies cover the whole process; thus results may be inconclusive. LCA results can be influenced by the heterogeneity of the AD method, reactor structure and conditions, and other influences. The absence of a conventional formation for LCAs utilized to the biogas yield method is a component in the inconsistent LCA results. Other considerations for instance systematic maintenance, transportation, system boundaries, temporal units, allocation preference, and waste disposal must be involved in the LCA plan. Notably, the economic pressure of both upstream and downstream systems should be included in the LCA phase. Inevitably, process design, optimization and modeling, and intensification will be the major future research subjects. This chapter provides a thorough and critical examination of the LCA and its sustainability evaluation for the whole AD procedure, which would be helpful in potential research
Challenges and emerging approaches in life cycle assessment of engineered nanomaterials usage in anaerobic bioreactor
Due to the increasing demand for sustainable energy sources and effective management of the ever-increasing volume of organic waste, anaerobic digestion (AD) has continued to play a crucial role in biogas production in recent years. Biochar (BC) is a highly flexible material manufactured by carbonizing organic resources like biomass and trash in line with circular economy standards and \“tailor-made\” for certain purposes. The capacity of BC as an additive to address various well-established crucial difficulties in AD methods has been extensively studied during the last 10 years. Nevertheless, a comprehensive and credible explanation of the BC-AD link remains elusive. The life cycle analysis (LCA) of the biogas enhancement mechanism would provide a quantitative indicator of its long-term viability. The reported LCA studies of AD processes are analyzed in this chapter, showing that few systematic studies cover the whole process; thus results may be inconclusive. LCA results can be influenced by the heterogeneity of the AD method, reactor structure and conditions, and other influences. The absence of a conventional formation for LCAs utilized to the biogas yield method is a component in the inconsistent LCA results. Other considerations for instance systematic maintenance, transportation, system boundaries, temporal units, allocation preference, and waste disposal must be involved in the LCA plan. Notably, the economic pressure of both upstream and downstream systems should be included in the LCA phase. Inevitably, process design, optimization and modeling, and intensification will be the major future research subjects. This chapter provides a thorough and critical examination of the LCA and its sustainability evaluation for the whole AD procedure, which would be helpful in potential research
Green biosynthesis of silver nanoparticles (AgNPs) FROM Vitex negundo plant extract and its phytochemical screening and antimicrobial assessment next to pathogenic microbes
In the present study, green synthesis of silver-nanoparticle (AgNPs) is demonstrated using plant extract of Vitex negundo. Plant extract through six different solvents, including petroleum ether, benzene, chloroform, acetone, methanol, and water, was prepared and further investigated for its antimicrobial and antifungal activities using different bacterial and fungal strains. The phytochemical analysis was performed, where saponins, tannins, steroids, flavonoids and glycosides were detected in acetone, chloroform and methanolic extract. Subsequent analysis of synthesized AgNPs through dynamic light scattering suggested that particle sizes were 10-300 nm in size. The study indicated that the chloroform, acetone, and methanol extracts of Vitex negundo showed good inhibitory activity against Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis based on the zone of inhibition. The antimicrobial activity of the synthesized AgNPs suggested that it can inhibit the growth of both gram +ve and gram -ve microorganisms. The MIC value of AgNPs of methanolic extract of V. negundo detected was 0.078 mg/mL, which was relatively lower than that of the MIC value of its crude extract (1.25mg/mL). The observed MIC values concluded that the synthesized AgNPs had better antimicrobial activity and could be necessary for various applications, including medicine, biology, and industr
Therapeutic implications of thymoquinone and its molecular and functional mechanisms against oral and lung cancer
Thymoquinone, a bioactive component of the black seed of Nigella sativa, has received great attention from researchers due to its wide spectrum of pharmacological potentials. The present review highlights the molecular and functional mechanisms of thymoquinone serving as a therapeutic molecule combating oral and lung cancer by following the most recent literature. This summarized the latest nanotechnological interventions enhancing the efficacy and availability of thymoquinone in the in-vitro and in-vivo cancer models. Thymoquinone exhibits a significantly promising anticancer effect against oral and lung cancer by prompting intrinsic and extrinsic pathways of apoptosis through the activation of different caspases cascades, up and downregulation of apoptotic genes, antitumor cell proliferation, ROS regulation, etc. The accomplished insight into molecular and functional mechanisms of thymoquinone particularly combating oral and lung cancer will provide a better understanding and exploration of thymoquinone in an ethnopharmacological context
Co-digestion of domestic kitchen food waste and palm oil mill effluent for biohydrogen production
Biohydrogen production from organic waste not only provides a sustainable way to produce biofuel but it also resolves the growing environmental concerns associated with agro-industrial waste. This research study investigated the biological hydrogen production potential in batch mode through co-digestion of domestic kitchen food waste (DKFW) and palm oil mill effluent (POME) under mesophilic conditions by immobilized Bacillus anthracis bacterial strain. The results showed that hydrogen production from co-digestion of DKFW and POME with an equal proportion of the combination is pH and temperature-dependent. Where, the elevated pH from 4.0 to 5.0 increases hydrogen production significantly; however, increasing the pH > 5.0 reduces productivity. Similarly, by raising the operating temperature from 25 °C to 35 °C the hydrogen production rate (HPR) increases up to 67 mL/h. Apart from hydrogen production, a reduction in chemical oxygen demand (COD) was observed by up to 72 % in this study. The improvement observed for HPR and a significant reduction in COD, suggests that the co-digestion of POME and DKFW is an ideal substrate for hydrogen production at operational temperatures and initial pH of 35 °C and 5.0, respectively. The strategy for utilizing the different organic waste together as a substrate provides a new avenue for the complex substrate for bioenergy production