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1.
J Contam Hydrol ; 263: 104339, 2024 04.
Article in English | MEDLINE | ID: mdl-38564944

ABSTRACT

Plastic particles, measuring <5 mm in size, mainly originate from larger plastic debris undergoing degradation, fragmenting into even smaller fragments. The goal was to analyze the spatial diversity and polymer composition of microplastics (MPs) in North Chennai, South India, aiming to evaluate their prevalence and features like composition, dimensions, color, and shape. In 60 sediment samples, a combined count of 1589 particles were detected, averaging 26 particles per 5 g-1 of dry sediment. The water samples from the North Chennai vicinity encompassed a sum of 1588 particles across 71 samples, with an average of 22 items/L. The majority of MPs ranged in size from 1 mm to 500 µm. The ATR-FTIR results identified the predominant types of MPs as polystyrene, polyvinyl chloride, polyethylene, polyethylene terephthalate, and polypropylene in sediment and water. The spatial variation analysis revealed high MPs concentration in landfill sites, areas with dense populations, and popular tourist destinations. The pollution load index in water demonstrated that MPs had contaminated all stations. Upon evaluating the polymeric and pollution risks, it was evident that they ranged from 5.13 to 430.15 and 2.83 to 15,963.2, which is relatively low to exceedingly high levels. As the quantity of MPs and hazardous polymers increased, the level of pollution and corresponding risks also escalated significantly. The existence of MPs in lake water, as opposed to open well water, could potentially pose a cancer risk for both children and adults who consume it. Detecting MPs in water samples highlights the significance of implementing precautionary actions to alleviate the potential health hazards they create.


Subject(s)
Environmental Monitoring , Geologic Sediments , Microplastics , Water Pollutants, Chemical , Microplastics/analysis , India , Water Pollutants, Chemical/analysis , Geologic Sediments/chemistry , Geologic Sediments/analysis , Humans , Risk Assessment , Plastics/analysis
2.
Environ Geochem Health ; 46(3): 102, 2024 Mar 04.
Article in English | MEDLINE | ID: mdl-38433158

ABSTRACT

Explosives are perilous and noxious to aquatic biota disrupting their endocrinal systems. Supplementarily, they exhibit carcinogenic, teratogenic and mutagenic effects on humans and animals. Henceforth, the current study has been targeted to biotransform the explosive, 2, 4, 6 trinitrophenol (TNP) by wetland peroxidase from Streptomyces coelicolor. A total peroxidase yield of 20,779 mg/l with 51.6 folds of purification was observed. In silico molecular docking cum in vitro appraisals were accomplished to assess binding energy and interacting binding site residues of peroxidase and TNP complex. TNP required a minimal binding energy of-6.91 kJ/mol and was subjected to biodeterioration (89.73%) by peroxidase in purified form, with 45 kDa and a similarity score of 34 by MASCOT protein analysis. Moreover, the peroxidase activity was confirmed with Zymogram analysis. Characterization of peroxidase revealed that optimum values of pH and temperature as 6 and 40 °C, respectively, with their corresponding stability varying from 3.5 to 7. Interestingly, the kinetic parameters such as Km and Vmax on 2,2'-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and H2O2 were 19.27 µm and 0.41 µm/min; 21.4 µm and 0.1 µm/min, respectively. Among the diverse substrates, chemicals and trace elements, ABTS (40 mM), citric acid (5 mM) and Fe2+ (5 mM) displayed the highest peroxidase activity. Computational docking and in vitro results were corroborative and UV-Vis spectroscopy, HPLC, FTIR and GC-MS indicated the presence of simple metabolites of TNP such as nitrophenols and benzoquinone, showcasing the efficacy of S. coelicolor peroxidase to biotransform TNP. Henceforth, the current study offers a promising channel for biological treatment of explosive munitions, establishing a sustainable green earth.


Subject(s)
Benzothiazoles , Hydrogen Peroxide , Peroxidase , Picrates , Sulfonic Acids , Animals , Humans , Molecular Docking Simulation , Peroxidases , Coloring Agents
3.
Bioresour Technol ; 388: 129725, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37683709

ABSTRACT

The suitability of biochar as a supplement for environmental restoration varies significantly based on the type of feedstocks used and the parameters of the pyrolysis process. This study comprehensively examines several aspects of biochar's potential benefits, its capacity to enhance crop yields, improve nutrient availability, support the co-composting, water restoration and enhance overall usage efficiency. The supporting mechanistic evidence for these claims is also evaluated. Additionally, the analysis identifies various gaps in research and proposes potential directions for further exploration to enhance the understanding of biochar application. As a mutually advantageous approach, the integration of biochar into agricultural contexts not only contributes to environmental restoration but also advances ecological sustainability. The in-depth review underscores the diverse suitability of biochar as a supplement for environmental restoration, contingent upon the specific feedstock sources and pyrolysis conditions used. However, concerns have been raised regarding potential impacts on human health within agricultural sectors.

4.
Bioresour Technol ; 372: 128679, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36706818

ABSTRACT

In recent years, biofuel or biogas have become the primary source of bio-energy, providing an alternative to conventionally used energy that can meet the growing energy demand for people all over the world while reducing greenhouse gas emissions. Enzyme hydrolysis in bioethanol production is a critical step in obtaining sugars fermented during the final fermentation process. More efficient enzymes are being researched to provide a more cost-effective technique during enzymatic hydrolysis. The exploitation of microbial catabolic biochemical reactions to produce electric energy can be used for complex renewable biomasses and organic wastes in microbial fuel cells. In hydrolysis methods, a variety of diverse enzyme strategies are used to promote efficient bioethanol production from various lignocellulosic biomasses like agricultural wastes, wood feedstocks, and sea algae. This paper investigates the most recent enzyme hydrolysis pathways, microbial fermentation, microbial fuel cells, and anaerobic digestion in the manufacture of bioethanol/bioenergy from lignocellulose biomass.


Subject(s)
Bioelectric Energy Sources , Biofuels , Biomass , Fermentation , Hydrolysis
5.
Sci Total Environ ; 858(Pt 1): 159681, 2023 Feb 01.
Article in English | MEDLINE | ID: mdl-36302412

ABSTRACT

Microplastics have been identified as an emerging pollutant due to their irrefutable prevalence in air, soil, and particularly, the aquatic ecosystem. Wastewater treatment plants (WWTPs) are seen as the last line of defense which creates a barrier between microplastics and the environment. These microplastics are discharged in large quantities into aquatic bodies due to their insufficient containment during water treatment. As a result, WWTPs are regarded as point sources of microplastics release into the environment. Assessing the prevalence and behavior of microplastics in WWTPs is therefore critical for their control. The removal efficiency of microplastics was 65 %, 0.2-14 %, and 0.2-2 % after the successful primary, secondary and tertiary treatment phases in WWTPs. In this review, other than conventional treatment methods, advanced treatment methods have also been discussed. For the removal of microplastics in the size range 20-190 µm, advanced treatment methods like membrane bioreactors, rapid sand filtration, electrocoagulation and photocatalytic degradation was found to be effective and these methods helps in increasing the removal efficiency to >99 %. Bioremediation based approaches has found that sea grasses, lugworm and blue mussels has the ability to mitigate microplastics by acting as a natural trap to the microplastics pollutants and could act as candidate species for possible incorporation in WWTPs. Also, there is a need for controlling the use and unchecked release of microplastics into the environment through laws and regulations.


Subject(s)
Environmental Pollutants , Water Pollutants, Chemical , Water Purification , Microplastics , Plastics , Wastewater/analysis , Waste Disposal, Fluid , Ecosystem , Water Pollutants, Chemical/analysis , Environmental Monitoring
6.
Chemosphere ; 313: 137475, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36528154

ABSTRACT

Anthropogenic toxins are discharged into the environment and distributed through a variety of environmental matrices. Trace contaminant detection and analysis has advanced dramatically in recent decades, necessitating further specialized technique development. These pollutants can be mobile and persistent in small amounts in the environment, and ecological receptors will interact with it. Despite the fact that few researches have been undertaken on invertebrate exposure, accumulation, and biological implications, it is apparent that a wide range of pollutants can accumulate in the tissues of aquatic insects, earthworms, amphipod crustaceans, and mollusks. Due to long-term stability during long-distance transit, a number of chemical and microbiological agents that were not previously deemed pollutants have been found in various environmental compartments. The uptake of such pollutants by the aquatic organism is done through the process of bioaccumulation when dangerous compounds accumulate in living beings while biomagnification is the process of a pollutant becoming more hazardous as it moves up the trophic chain. Organic and metal pollution harms animals of every species studied so far, from bacteria to phyla in between. The environmental protection agency says these poisons harm humans as well as a variety of aquatic organisms when the water quality is sacrificed in typical wastewater treatment systems. Contrary to popular belief, treated effluents discharged into aquatic bodies contain considerable levels of Anthropogenic contaminants. This evolution necessitates a more robust and recent advancement in the field of remediation and their techniques to completely discharge the various organic and inorganic contaminants.


Subject(s)
Environmental Pollutants , Water Pollutants, Chemical , Animals , Humans , Ecosystem , Environmental Pollutants/analysis , Water Pollutants, Chemical/analysis , Aquatic Organisms , Water Quality , Environmental Monitoring/methods
7.
J Environ Manage ; 330: 117132, 2023 Mar 15.
Article in English | MEDLINE | ID: mdl-36584468

ABSTRACT

Herein, the ternary CdS/BiVO4/g-C3N4 (CBG) hybrid semiconductor photocatalyst was prepared via a hydrothermal technique. The synthesized photocatalysts were thoroughly characterized using powder XRD, XPS, FTIR, SEM, TEM, and UV-DRS to investigate the microstructural, morphological attributes, and optical properties. The photocatalytic activity of the ternary CBG hybrid semiconductor was assessed through the photodegradation of Methylene Blue (MB) aqueous dye under visible light. The outcomes exhibited that the CBG hybrid semiconductor showed excellent photocatalytic activity (about 94.5% after 120 min) compared to the results obtained with the pristine materials or the other composite (CdS/BiVO4). The enhancement of photocatalytic activity can be due to the construction of heterojunctions among g-C3N4, CdS, and BiVO4, which improves charge transfer efficiency and hence favors the degradation of organic dyes. Moreover, the as-prepared photocatalyst showed excellent stability after five cycles, indicating good stability and reusability. Subsequently, a possible photocatalytic mechanism was proposed based on the experimental results. The current investigation provides a promising strategy to promote photocatalytic activity to eliminate waterborne contaminants.


Subject(s)
Methylene Blue , Nanocomposites , Light , Coloring Agents
8.
Chemosphere ; 310: 136757, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36228720

ABSTRACT

Accumulation of plastics alarms a risk to the environment worldwide. As polyethylene pterephthalate (PET) degrades slowly and produces hazardous substances, therefore, it is now essential to eliminate plastic wastes from the environment. Given that, the current study is concerned with PET degradation potential of naturally occurring microbial strains isolated from plastic waste dumping sites, Sarcina aurantiaca (TB3), Bacillus subtilis (TB8), Aspergillus flavus (STF1), Aspergillus niger (STF2). To test the biodegradability of PET films, the films were incubated for 60 days at 37 °C with the microorganisms designated as TB3, TB8, STF1, STF2 and the microbial consortium (TB3+TB8+STF1+STF2) in Minimal Salt Medium and Bushnell Hass Broth. Hydrophobicity, viability, and total protein content of isolates were investigated. Using Field Emission Scanning Electron Microscopy and Fourier Transform Infrared Spectrophotometry to measure variations in functional groups and carbonyl index on PET surface, biodegradation process was affirmed by fissures and modified surfaces. Results revealed that the microbial consortium (S. aurantiaca + B. subtilis + A. flavus + A. niger) that the weight loss of PET films was 28.78%. The microbial consortium could be used to treat PET waste, posing no health or environmental risks. The developed microbial consortium has the potential to degrade PET, hence can be employed for eliminating PET in plastic contaminated sites.


Subject(s)
Plastics , Polyethylene Terephthalates , Biodegradation, Environmental , Polyethylene/metabolism , Microbial Consortia
9.
Bioresour Technol ; 364: 128057, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36195218

ABSTRACT

Reducing CO2 emissions using biomass is gaining popularity as an environmentally friendly strategy. Due to high growth rates, low production costs, and ability to withstand harsh conditions, microalgae have become quite popular. Microalgae may also undertake photosynthesis, converting CO2 and solar energy into sugar before becoming biomass, making them an excellent source of renewable and promising biofuels. CO2 sequestration and biofixation was utilized to compare the synthesis of biodiesel as a third-generation biofuel from various types of wastewater was also used as a source for the algal cultivation. This review article focuses on recent developments, research discoveries in the field of microalgal CO2 capture modification and the optimization of conversion efficiency. This review is intended to serve as a helpful and reference for the use of wastewater treatment with microalgae to collect CO2. The overarching objective of this study is to assist wastewater treatment systems in achieving carbon neutrality.


Subject(s)
Microalgae , Wastewater , Carbon , Carbon Dioxide , Biofuels , Biomass
10.
Chemosphere ; 307(Pt 3): 136017, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35977566

ABSTRACT

The need of the hour relies on finding new but sustainable ways to curb rising pollution levels. The accelerated levels of urbanization and increase in population deplete the finite resources essential for human sustenance. In this aspect, water is one of the non-renewable sources that is running out very fast and is polluted drastically day by day. One way of tackling the problem is to reduce the pollution levels by decreasing the usage of chemicals in the process, and the other is to find ways to reuse or reduce the contaminants in the effluent by treatment methods. Most of the available water recycling or treatment methods are not sustainable. Some of them even use toxic chemicals in the processing steps. Treatment of organic wastes from industries is a challenging task as they are hard to remove. Electrocoagulation is one of the emerging water treatment technologies that is highly sustainable and has a comparatively cheaper operating cost. Being a broad-spectrum treatment process, it is suitable for treating the most common water pollutants ranging from oils, bacteria, heavy metals, and others. The process is also straightforward, where electrical current is used to coagulate the contaminates. The presence of carcinogens in these waste water increases the need for its treatment towards further use. The present investigation is made as an extensive analysis of the emerging carcinogens and their various sources from process industries, especially in the form of organic waste and their removal by electrocoagulation and its coupled techniques. The paper also aims to ascertain why the electrocoagulation technique may be a better alternative compared with other methods for the removal of carcinogens in organic wastewater, an analysis which has not been explored before.


Subject(s)
Metals, Heavy , Water Pollutants, Chemical , Water Pollutants , Carcinogens/analysis , Electrocoagulation/methods , Humans , Industrial Waste/analysis , Metals, Heavy/analysis , Oils , Prospective Studies , Waste Disposal, Fluid/methods , Wastewater/analysis , Water Pollutants/analysis , Water Pollutants, Chemical/analysis
11.
Environ Res ; 214(Pt 2): 113867, 2022 11.
Article in English | MEDLINE | ID: mdl-35843279

ABSTRACT

Graphene has revolutionized the field of energy and storage sectors. Out of the total number of nosocomial infections diagnosed all around the world, the majority of the cases (around 70%) are found to be due to the medical device or assistance utilized while treating the patient. Combating these diseases is vital as they cause a nuisance to the patients and medical practitioners. Coatings of graphene and its derivatives hold the key to the formation of special surfaces that can rupture microbial cells using their sharp edges, ultimately leading to nuclear and cellular fragmentation. Their incorporation as a whole or as a part in the hospital apparel and the medical device has aided medical practitioners to combat many nosocomial diseases. Graphene is found to be highly virulent with broad-spectrum antimicrobial activity against nosocomial strains and biofilm formation. Their alternate mode of action like trapping and charge transfer has also been discussed well in the present review. The various combinational forms of graphene with its conjugates as a suitable agent to combat nosocomial infections and a potential coating for newer challenges like COVID-19 infections has also been assessed in the current study. Efficiency of graphene sheets has been found to be around 89% with a reaction time as less as 3 h. Polymers with graphene seem to have a higher potency against biofilm formation. When combined with graphene oxide, silver nanoparticles provide 99% activity against nosocomial pathogens. In conclusion, this review would be a guiding light for scientists working with graphene-based coatings to unfold the potentials of this marvelous commodity to tackle the present and future pandemics to come.


Subject(s)
COVID-19 , Cross Infection , Graphite , Metal Nanoparticles , Anti-Bacterial Agents/pharmacology , Biofilms , Cross Infection/epidemiology , Cross Infection/prevention & control , Humans , Silver
12.
Chemosphere ; 298: 134268, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35276113

ABSTRACT

Microplastic (MP), as a pollutant, is currently posing a biological hazard to the aquatic environment. The study aims to isolate, quantify, and characterize the MP pollutants in sediment samples from 14 study sites at Kaveri River, Killa Chinthamani, Tiruchirappalli, South India. With Sediment-MP Isolation (SMI) unit, density separation was done with a hydrogen peroxide solution. Four forms of MPs namely, fragments, films, foams, and fibers with orange, white, green, and saffron red were observed. The plenitude and distribution of four forms of MPs and natural substrates were geometrically independent, with large amounts of microfragments within the research region accounting for 79.72% variation by Principal Component Analysis. FT-IR analyses of MPs showed the presence of polyamide, polyethylene, polyethylene glycol, polyethylene terephthalate, polypropylene, and polystyrene. Additionally, the scanning electron microscopic analysis revealed that the MPs have differential surface morphology with rough surfaces, porous structures, fissures, and severe damage. Most MPs comprised Si, Mg, Cu, and Al, according to energy dispersive X-ray analyses. The combined SMI, instrumental analyses and evaluation (heat map) of MPs in river sediments help assess contamination levels and types of MPs. The findings might provide an insight into the status of MPs in Kavery River sediments that could help in formulating regulations for MPs reduction and contamination in rivers eventually to protect the environment.


Subject(s)
Environmental Pollutants , Water Pollutants, Chemical , Environmental Monitoring , Environmental Pollutants/analysis , Geologic Sediments/chemistry , Microplastics , Plastics , Rivers/chemistry , Spectroscopy, Fourier Transform Infrared , Water Pollutants, Chemical/analysis
13.
Chemosphere ; 296: 133976, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35176298

ABSTRACT

Microplastics in personal care and food products are given much importance globally due to the adverse impact of microplastics on living beings. In the present study, microplastics from ten different commercially sold toothpaste in India were extracted by vacuum filtration and characterized with microscopic and Fourier-transform infrared spectroscopic analyses. Results revealed that colorless fragments and fibers were the microparticle types of common occurrence which ranged from 0.2 to 0.9% weight in the toothpaste with an abundance range of 32.7-83.2%. Fifty percent of the toothpaste samples showed more than 50% microplastic particle abundance indicating that the microplastic plastic particles were added by the manufacturers. The minimum size of microplastics recorded in the present study was 3.5 µm with a maximum size exceeding 400 µm. The maximum number of microplastics in the toothpaste was 167, 508 and 193 respectively, distributed in the size range of <100 µm, 100-400 µm, and >400 µm. The present study recorded four major polymer types, viz., cellophane, polypropylene, polyvinyl chloride, and polyamide in the toothpaste samples. Surprisingly, polyethylene-a common polymer reported in toothpaste was not traced in the present samples. Regarding the Indian context, the current study is a new addition to the knowledge of the occurrence of microplastics in toothpaste. The average annual addition of microplastics into the environment through toothpaste was calculated as 1.4 billion g/year for India, posing a significant threat to the environment.


Subject(s)
Microplastics , Water Pollutants, Chemical , Environmental Monitoring , Plastics/chemistry , Polymers , Risk Assessment , Toothpastes , Water Pollutants, Chemical/analysis
14.
Bioresour Technol ; 346: 126442, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34848334

ABSTRACT

The present study proposes a system for co-composting food waste and poultry manure amended with rice husk biochar at different doses (0, 3, 5, 10%, w/w), saw dust, and salts. The effect of rice husk biochar on the characteristics of final compost was evaluated through stabilization indices such as electrical conductivity, bulk density, total porosity, gaseous emissions and nitrogen conservation. Results indicated that when compared to control, the biochar amendment extended the thermophilic stage of the composting, accelerated the biodegradation and mineralization of substrate mixture and helped in the maturation of the end product. Carbon dioxide, methane and ammonia emissions were reduced and the nitrogen conservation was achieved at a greater level in the 10% (w/w) biochar amended treatments. This study implies that the biochar and salts addition for co-composting food waste and poultry manure is beneficial to enhance the property of the compost.


Subject(s)
Composting , Refuse Disposal , Animals , Charcoal , Dust , Manure , Minerals , Nitrogen/analysis , Poultry , Salts , Soil
15.
J Environ Manage ; 301: 113849, 2022 Jan 01.
Article in English | MEDLINE | ID: mdl-34619586

ABSTRACT

Engine oil consists of hazardous substances that adversely affect the environment and soil quality. Bioremediation (employing organisms) is an appropriate technique to mitigate engine oil pollution. In the present study, the earthworm species, Drawida modesta (epigeic) and Lampito mauritii (anecic) were used to restore the soil polluted with polycyclic aromatic hydrocarbons (PAHs) and total petroleum hydrocarbons (TPHs) from used engine oil. Four treatments were set up in addition to positive and negative controls. A maximum of 68.6% PAHs and 34.3% TPHs removal in the treatment with soil (1 kg), cow dung (50 g), used engine oil (7.5 mL) and earthworms was recorded after 60 days. Undoubtedly, earthworms effectively removed PAHs and TPHs from the oil-contaminated soil. PAHs were more strongly accumulated in D. modesta (16.25 mg kg-1) than in L. mauritii (13.25 mg kg-1). Further, histological analysis revealed the epidermal surface irregularity, cellular disintegration, and cellular debris in earthworms. The pH (6.3%), electrical conductivity (12.7%), and total organic carbon (35.4%) were significantly (at P < 0.05) decreased after 60 days; while, total nitrogen (62%), total potassium (76.2%), and total phosphorus (19.2%) were substantially increased at the end of the experiment. The seed germination assay with fenugreek indicates that germination percentage (95%), and germination index (179), were dramatically increased in earthworm inoculated treatments when compared to the negative control (without earthworms). The results reveal that there is a great scope for utilizing the earthworms, D. modesta and L. mauritii for the bioremediation of soils contaminated with PAHs and TPHs.


Subject(s)
Oligochaeta , Polycyclic Aromatic Hydrocarbons , Soil Pollutants , Animals , Biodegradation, Environmental , Cattle , Female , Hydrocarbons , Soil , Soil Pollutants/analysis
16.
Chemosphere ; 291(Pt 2): 132675, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34710456

ABSTRACT

Hazardous coir industrial waste, coir pith has been subjected to 50 days vermicomposting with Eudrilus eugeniae by amending nitrogenous legume plant, Gliricidia sepium together with cattle dung in different combinations, after 21 days precomposting using Pleurotus sajor-caju spawn. An increase in electrical conductivity, total NPK and calcium, and a decrease in organic matter, total organic carbon, C/N ratio, C/P ratio and total phenolic content in the final vermicompost were observed. Dehydrogenase, urease and cellulase activity peaked up to 30 days of vermicomposting and then declined. The phytotoxicity studies with Brassica juncea, C/N ratio and enzyme activities confirmed the stability and maturity of vermicompost. The results also demonstrated that the 2:3:1 ratio (coir pith + Gliricidia sepium + cow dung) is a suitable effective combination for nutrient-rich (N: 2.43%; P: 0.92%; K: 2.09%) vermicompost production. The total phenolic contents declined during the vermicomposting with a lower final content of 21.26 mg/g GAE in 2:3:1 combination of substrates from the initial level (105.56 mg/g GAE). Besides, the concentration of total phenol contents inversely related to the germination index of Brassica juncea (r = -0.761), indicating that the phenolic content could also play an important role in phytotoxicity. Growth and fecundity of Eudrilus eugeniae in 2:3:1 combination revealed the acceptability and rapid decomposition of coir pith substrate into vermifertilizer.


Subject(s)
Manure , Oligochaeta , Animals , Cattle , Female , Lignin/analogs & derivatives , Soil
17.
Chemosphere ; 288(Pt 2): 132534, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34648786

ABSTRACT

The present investigation has been carried out to utilize waste animal (Ox) bone for the progress of an innovative, low-budget, pollution free, and extremely resourceful heterogeneous catalyst synthesis for Jatropha curcas oil (JCO) conversion into biodiesel. The heterogeneous catalyst synthesized was characterized by its basic strength and subjected to spectroscopic (Fourier TransformInfrared and X-Ray Diffraction) and thermogravimetric analyses. Also, the physical properties of produced biodiesel were studied. The calcined Ox bone catalyst characterization distinctly showed that there was a tremendous catalytic activity for biodiesel synthesis. The kinetic study was accomplished employing a tri-necked RB flask furnished with a condenser and agitator. At the agitation speed of 500 rpm, 5% catalyst loading rate (w/w) of oil and 12:1 methanol-oil ratio (molar), biodiesel yields were tracked based on reaction time (1-4 h) and temperature (313-338 K). The temperature at 338 K was found to be optimal to obtain maximum (96.82%) biodiesel yield. Pseudo-first order kinetics was followed in the reaction. The energy required for the activation (Ea) was 38.55 kJ mol-1 with a frequency factor (ko) of 7.03 × 106 h-1. The reusability studies demonstrated that the calcined animal bone catalyst was much stable up to three cycles with >90% FAME yield, which was reduced significantly (P < 0.05) to 61% in the fourth cycle. The outcome of this investigation brought to light the possibilities of utilizing calcined Ox bone catalyst and JCO as low-cost and frequently obtainable discarded waste materials that can be used as feedstock for the commercial-scale generation of biodiesel to fulfill the prospective community demands.


Subject(s)
Jatropha , Biofuels , Kinetics , Physics , Prospective Studies
18.
Bioresour Technol ; 344(Pt B): 126300, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34752882

ABSTRACT

The prominent characteristics of the biochar, high porosity, sorption capacity with low density improve the aeration, making it a desirable amendment material for composting process. The composting efficiency was analysed by the impact of rice husk biochar amendment (0, 2, 4, 6, 8 and 10%) in the presence of salts for the co-composting of food waste and swine manure, in composting reactors for 50 days. Results revealed that biochar amendment had improved the degradation rates by microbial activities in comparison with control. The final compost quality was improved by reducing the bulk density (29-53%), C/N ratio (29-57%), gaseous emissions (CO2, CH4, and NH3) and microbial pathogens (Escherichia coli and Salmonella sp.). However, 6% biochar amendment had significant improvement in compost quality, degradation rates and nutritional value which is recommended as the ideal ratio for obtaining mature compost from the feedstock, food waste and swine manure.


Subject(s)
Composting , Refuse Disposal , Animals , Charcoal , Food , Gases , Manure , Nitrogen/analysis , Nutrients , Salts , Soil , Swine
19.
Chemosphere ; 287(Pt 4): 132439, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34606889

ABSTRACT

The rising global population and their food habits result in food wastage and cause an obstacle in its treatment and disposal. Due to the rapid shift in the lifestyle of the human population and urbanization, almost one-third of the food produced is wasted from various sectors like domestic sources, agricultural sectors, and industrial sectors. These food resources squandered are rich in organic biomolecules which can cause complications upon direct disposal in the environment. Conventional disposal methods like composting, landfills and incineration demand high costs besides causing severe environmental and health issues. To overcome these demerits of the conventional methods and to avoid the loss of rich organic food resources, there is an immediate need for a sustainable and eco-friendly solution for the valorization of the food wastes. Microbial fuel cells (MFCs) are gaining attention, due to their ideal approach in the production of electricity and parallel treatment of organic food wastes. The MFCs are significant as an innovative approach using microorganisms and oxidizing the organic food wastes into bio-electricity. In this review, the recent advancements and practices of the MFCs in the field of food waste treatment and management along with electricity production are discussed. The major outcome of this work highlights the setting up of MFC for the treatment of higher volumes of food waste residues and enhancing the bioelectricity production in an optimal condition. For further improvements in the food waste treatments using MFCs, greater understanding and more research needs are to be focused on the commercialization, different operational modes, operational types, and low-cost fabrication coupled with careful examination of scale-up factors.


Subject(s)
Bioelectric Energy Sources , Refuse Disposal , Electricity , Electrodes , Food , Humans , Incineration
20.
Environ Pollut ; 290: 117989, 2021 Dec 01.
Article in English | MEDLINE | ID: mdl-34433126

ABSTRACT

Surface and water bodies in many parts of the world are affected due to eutrophication, contamination and depletion. The approach of wastewater treatment using algae for eliminating nutrients and other pollutants from domestic wastewater is growing interest among the researchers. However, sustainable treatment of the wastewater is considered to be important in establishing more effective nutrient and pollutant reduction using algal systems. In comparison to the conventional method of remediation, there are opportunities to commercially viable businesses interest with phycoremediation, thus by achieving cost reductions and renewable bioenergy options. Phycoremediation is an intriguing stage for treating wastewater since it provides tertiary bio-treatment while producing potentially valuable biomass that may be used for a variety of applications. Furthermore, the phycoremediation provides the ability to remove heavy metals as well as harmful organic substances, without producing secondary contamination. In this review, the role of microalgae in treating different wastewaters and the process parameters affecting the treatment and future scope of research have been discussed. Though several algae are employed for wastewater treatment, species of the genera Chlamydomonas, Chlorella, and Scenedesmus are extensively utilized. Interestingly, there is a vast scope for employing algal species with high flocculation capacity and adsorption mechanisms for the elimination of microplastics. In addition, the algal biomass generated during phycoremediation has been found to possess high protein and lipid contents, promising their exploitation in biofuel, food and animal feed industries.


Subject(s)
Chlorella , Environmental Pollutants , Microalgae , Animals , Biodegradation, Environmental , Biomass , Plastics , Wastewater
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