Tannery Waste Research Articles

Exploring newly isolated thermotolerant, halotolerant and antimicrobial resistant Bacillus subtilis ProNTL1 from tannery waste and its alkaline protease production.

A hydrolytic enzyme called protease from microbial sources has expansive applications in leather as well as tannery industries and thus leaves no choice but to discover a potential candidate for efficient yield of protease with eccentric characteristics. In the current study, using skim milk agar medium, three bacterial strains (Pro SS14, Pro NTL1, Pro SM) were identified for protease production out of thirty tannery waste samples. The bacterial isolates were identified through morphological, biochemical and molecular basis and the highest protease producer (134U/mL) having the paramount protein content (8.75%) with the greatest biomass (absorbance 1.7 at 600nm) was further bioinformatically identified as Bacillus subtilis Pro NTL1. Moreover, the cultural conditions-pH, temperature, incubation period and salinity were tested to get the optimized condition for the three isolates where Bacillus subtilis Pro NTL1 gave best growth at pH 9 demonstrating alkaline protease producing capability, at 45°C for 72h proving its thermotolerance characteristics and at 3% NaCl concentration declaring its halotolerance property. Furthermore, following Kirby-Bauer agar disc diffusion technique, the antimicrobialsusceptibility pattern was investigated showing Bacillus subtilis Pro NTL1 was resistant to ampicillin, penicillin, sulfafurazole and sensitive to amoxicillin, gentamycin, cefotaxime, kanamycin, imipenem, tetracycline. Additionally, Bacillus subtilis Pro NTL1 showed antagonistic activity against three pathogens named Bacillus cereus, Bacillus megaterium and Escherichia coli. Thus, these findings suggest that Bacillus subtilis Pro NTL1 is a newly isolated strain with unique features which might help to contribute in several biotechnological purposes with significant industrial benefits.

Analysis of syngas and power production from tannery waste via gasification process using integrated thermal equilibrium simulation model

Managing high-ash sludge from tanneries is a significant challenge and requires investigating their conversion to valuable goods. This study explores the use of gasification processes to convert tannery waste into syngas and the use of syngas for power generation. In this respect, the integrated process thermal equilibrium simulation model has been developed using the Aspen Plus® V12. This model consists of (1) a steam gasification model for syngas production and (2) a power generation model for converting syngas into electricity. In addition, sensitivity analysis has been carried out to determine the effects of temperature (650–900 °C), steam flow (500–2000 kg/h), and CaO flow (0.1500 kg/h) on the composition and power generation of syngas. Changes in steam flow rate at constant temperature (cao flow rate 1500 kg/h) show an increase in H2 content to 80 % and a decline in CO and CH4 content. This increases total power output from 3680 kW to 4001 kW, temperature increases from 650 to 900 °C, and steam flow increases from 500 to 2000 kg/h from 3500 to 4600 kW. Finally, the impact of CaO as a sorbent is significant in electricity generation and CO2 mitigation, increasing to over 600 kW of energy output. This work could contribute to converting waste into energy, which could have a significant financial impact on the tannery industry.

Unraveling latent affinity of strategically designed histidine-rich biosurfactant via tannery waste bio-upcycling in environmentally-relevant lignin removal from pulp and paper industry effluent

Bioremediation of pulp and paper industry (PPI) effluent is hindered due to biorefractory lignin. Herein, we demonstrate a lignin-specific designer biosurfactant with synergistic binding sites for enhanced lignin removal from PPI effluent. The histidine rich-cationic lipoprotein biosurfactant (HR-CLB) was synthesized by Bacillus tropicus using tanning industry solid waste, animal fleshing by de novo substrate-dependent synthesis pathway. Interestingly, the HR-CLB anchored functionalized carbon (HR-CLBAFC) demonstrated a high lignin sequestration capacity of 93.2 mg/g HR-CLBAFC at optimized time, 60 min; pH, 5; temperature, 45 °C; and mass of HR-CLBAFC, 1.0 g. The sequestration was confirmed by HR-SEM, UV–Vis., FT-IR, and WCA analyses. The isotherm studies revealed the involvement of Freundlich isotherm (regression coefficient, R2: 0.988) in regulating lignin sequestration onto HR-CLBAFC with a Freundlich constant (Kf) of 16.46 ((mg/g)(L/mg)1/n). Moreover, the kinetics studies divulged the contribution of the pseudo-second-order kinetic model (R2: 0.992) in regulating the dynamic mechanism of lignin sequestration onto HR-CLBAFC with a rate constant (k2) of 0.00022 g/mg min. Additionally, the thermodynamics studies discovered a positive Gibbs free energy (ΔG: +170 kJ/mol) and entropy (ΔS°: +130 kJ/mol), indicating the involvement of chemical interaction during the sequestration. Furthermore, the mechanistic study confirmed the role of an incomplete valence shell of nitrogen in histidine centers of HR-CLB in regulating electrostatic interaction with lignin molecules during the sequestration process. Subsequently, the HR-CLBAFC applied for lignin sequestration from the real-time PPI effluent demonstrated an outstanding sequestration efficiency (>99.4%), confirming the unequivocal potential of the HR-CLBAFC matrix in lignin sequestration from real-time PPI effluent.

Recycling of collagen from solid tannery waste and prospective utilization as adhesives.

Abstract This study explores the innovative potential of recycled collagen derived from tannery waste for use in high-performance adhesive formulations. The leather industry generates significant amounts of solid waste, primarily from chromium-tanned leather, which poses substantial environmental challenges. Recent advancements in recycling techniques have opened new avenues for repurposing this waste, particularly through collagen extraction, which comprises about 30-35% of tannery residues. This research systematically reviews the methods and applications of collagen extraction, highlighting the material’s versatility and environmental benefits when used as a bio-adhesive. The review identifies key challenges such as low water resistance, shear strength, and adhesiveness in collagen-based adhesives compared to synthetic counterparts. However, innovative solutions are emerging, including the incorporation of silane coupling agents and cross-linking technologies that significantly improve the water resistance and mechanical properties of these adhesives. Economic analyses further support the viability of using tannery waste-derived collagen in adhesive production, aligning with global sustainability goals and reducing reliance on petrochemical-based adhesives. Despite these advancements, the transition from laboratory research to commercial applications remains a significant challenge. Current studies primarily focus on small-scale experiments, with limited pilot-scale studies available. Nonetheless, the potential for collagen-based adhesives to replace harmful chemicals in industrial applications is promising, especially in sectors requiring biodegradable and non-toxic materials. This review concludes that while significant progress has been made, further research is necessary to overcome existing limitations and fully realize the commercial potential of collagen-based adhesives derived from tannery waste.

Ecological implications of chromium-contaminated effluents from Indian tanneries and their phytoremediation: a sustainable approach.

Industrial activities are paramount to sustaining the economy in a rapidly developing nation and global powerhouse like India. Leather industries are important in the country's economic map due to the high revenue and employment generation opportunities. Several of these industries contribute largely to environmental pollution. The pollution of the environment is mainly caused by improper disposal of the tannery effluents that are highly rich in hexavalent chromium, a potent human carcinogen. Hexavalent chromium imparts toxic effects on the biotic components, which include plants, animals, and humans. The review portrays the current status of the Indian leather tanning sector and its impact on the Indian economy. The process of chromium tanning and its adverse effects on the environmental biotic components have been briefly discussed. Phytoremediation of these effluents using suitable hyperaccumulating plants has been suggested as an eco-friendly and cost-effective approach for the sustainable restoration of the polluted environment. The mechanism behind the remediation approach and the factors influencing it have been detailed. The manuscript briefly discusses some important advancements in the field of phytoremediation and emerging technologies and concludes by emphasizing further research for sustainable management of tannery wastes.

Flow Properties o f Tannery Waste Liquor

Objective: A water treatment facility is to be erected nearby the industrial tanning complex, recently established East of Cairo, Egypt. This paper represents a contribution to studying the flow characteristics of the produced tannery waste effluents. A dried sample of tannery waste was chemically analyzed by X-ray fluorescence and its particle size distribution was determined. Next, rheological measurements were carried out on the waste slurry produced at temperatures ranging from 10°C to 40°C and three different solid concentrations, by weight: 20%, 25%, and 30%. The results showed that all waste suspensions under all conditions of solid content and temperature behaved as shear-thinning liquids. Flow indices of all suspensions generally tended to increase with temperature and solid concentration. Activation energies for viscosity were correlated to an increase in solid concentration and showed a decreasing pattern. All samples exhibited a thixotropic character that decreased with increased temperature and dilution of the suspension. The maximum pressure drops per unit length of a pipeline used to transport the waste suspension to the treatment unit was evaluated and found to increase with solid concentration and decrease with increasing temperature. Keywords: Rheology, Tannery waste slurry, Solid content, Temperature

Keratin hydrolysate as a chrome exhaust aid and keratin filler in leather processing: A cleaner technology approach for tannery solid waste management and leather manufacturing

Hair burning unhairing and dampening of tannery wastes during the hair-saving unhairing process are becoming significant problems in the tanning industry. Therefore, this research article focuses on the extraction of keratin hydrolysate (KH) and its application as a chrome exhaust aid and keratin filler in leather manufacturing process. The structure, morphology and functional groups of the extract were examined using X-Ray Diffractometer (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrometer (FTIR), respectively. To study and contrast the degree of improvement in chromium uptake, the KH solution was applied both before tanning on the pickled pelt and after tanning during basification. The thermal stability, physical strength characteristics and organoleptic properties of the leathers obtained were characterized. Furthermore, the environmental impact of the tanning system was assessed through a comparative analysis of the spent liquors. Finally, experimental retanning process was conducted to replace the commercial protein filler (Celatan F: 50, 75, and 100 %) with KH solution, with concurrent processing of control leather using conventional chrome tanning agent at 6 % dosage of chromium. The FTIR analysis of the extract confirmed the presence of alkyl side chains of amino acids as well as carboxylic, amide, carboxyl group and aldehyde functional groups at 1400-1700 cm−1,3,303.46 cm−1,3270 cm−1 and 2752 cm−1, respectively. XRD spectrum showed two diffraction peaks at 2 theta values of 9.36° and 21.16°, respectively. Leathers with improved mechanical strength, organoleptic properties and thermal stability were obtained with 100 % substitution of Celatan F at pH 6 and 10 % chromium dosage. It was also discovered that the shrinkage temperature of the experimental leather was enhanced to more than 105 °C. Environmental impact evaluation on the spent liquor showed that the complete replacement of Celatan F with KH solution brought about a notable decrease in COD and TDS in the spent liquor. The extraction and application of tannery hair waste-based keratin hydrolysate as an efficient, environmentally friendly chrome exhaust aid and keratin filler has been attempted and established in this research article.

Hydrocarbon fuel blendstock from tannery waste: energy from fleshing oil via gas phase catalytic cracking

AbstractThe global leather industry generates large quantities of tannery waste. These leather wastes have a high fat content, which could be used for valuable products. This study focuses on the conversion of such fats into a biocrude to be distilled into a bio‐based hydrocarbon fuel blendstock. A biorefining technology defined as ‘gas‐phase catalytic cracking’ (GCC) over activated carbons, also referred to as ‘greasoline’, was used for conversion, and GC–MS/FID and simulated distillation for product characterization. The experiments were performed at ambient pressure and 450 °C reaction temperature, with 40 g h−1 of fat being processed over 55 g of steam‐activated carbon under a nitrogen atmosphere for a duration of 4 h. Fleshing oil obtained from the pre‐fleshing of double‐face lambskins by extraction with supercritical CO2 yielded almost the same mass fraction of organic liquid product (OLP) (59 wt%) as palm oil used as a reference (62 wt%). In both OLPs, n‐alkanes from heptane to heptadecane predominate, with a clear predominance of n‐pentadecane and n‐heptadecane and no unsaturated molecules among the major components. For both oils, about 85 wt% of the OLP is in the boiling range of diesel fuel, and about another 12 wt% is in the gasoline boiling range. The results show that mixtures of fatty acids extracted from leather tanning wastes can be used for value‐added products – in particular for the production of bio‐based hydrocarbon fuel blendstock.

Valorisation of Tannery Waste to Recover Chromium with a View to Reusing It in Industrial Practise.

This paper presents the basic assumptions of the concept of a new technology for the valorisation of chromium tannery waste. It assumes the use of an integrated system of the thermal pressure hydrolysis process and membrane filtration techniques for the recovery of chromium compounds and the use of a separated organic matter during anaerobic fermentation. According to the assumptions of the developed technological concept, at the first stage, the crushed mixture of chromium tannery waste is decomposed in the process of thermal pressure hydrolysis using appropriate process conditions in an alkaline environment. Then, the liquid product of this process (the so-called hydrolysate) is processed using centrifugal force separation and ultrafiltration. Such activities enable the recovery of chromium compounds for rawhide currying and concentration of organic matter (fats, proteins) with energy potential. Research carried out under conditions similar to real operating conditions proved that chromium compounds recovered from waste can be successfully used in the processing of cowhides intended for the production of footwear. The industrial implementation of the developed technology for valorising chromium tannery waste would enable the transition from a linear to a circular economy.

Impact of tannery wastes on anaerobic co-digestion: enhancing biogas production and process efficiency

The study investigates the potential of anaerobic co-digestion (AcoD) as a sustainable solution for managing putrescible organic waste generated by leather processing. Three experiments were conducted to assess the impact of various tannery wastes, pretreatment methods, and waste combinations on methane production. Experiment 1 demonstrated that co-digesting tannery wastewater primary sludge (TWPS) and fleshings significantly increased methane yield compared to digesting TWPS alone, though the addition of chromium- and vegetable-tanned leather wastes decreased yield. Experiment 2 explored TWPS pretreatment methods and found that ultrasonic pretreatment increased soluble chemical oxygen demand (SCOD) but did not significantly improve methane yield, suggesting that pretreatment may not be necessary. Experiment 3 revealed that increasing the proportion of fleshings to TWPS resulted in higher methane yield, ranging from 226.52 mL/gVS with 6% fleshings to 395.71 mL/gVS and 538.34 mL/gVS with 12% and 20% of fleshings, respectively. Additionally, this increase in fleshings also led to a reduction in digester volume. These findings highlight the importance of AcoD in addressing both environmental and economic challenges in the leather industry.Graphical

Analysis and Treatment of Tannery Waste Water by using Combined Filtration and Coagulation Treatment Process

Abstract: Industry generates significant volumes of waste water laden with various pollutants, including suspended solids, organic compounds and heavy metals presenting considerable environmental challenges. This study proposes an innovation approach for the analysis and treatment of tannery waste water using a combined filtration and coagulation treatment process. The analysis phase involves a comprehensive characterization of the tannery effluent, identifying key contaminants and their concentrations. This understanding informs the design of an efficient treatment strategy. The treatment process integrates two key techniques i.e. filtration and coagulation.

Evaluating the efficacy of vermicomposted products in rain-fed wetland rice and predicting potential hazards from metal-contaminated tannery sludge using novel machine learning tactic

The study assessed the ecotoxicity and bioavailability of potential metals (PMs) from tannery waste sludge, alongside addressing the environmental concerns of overuse of chemical fertilizers, by comparing the impacts of organic vermicomposted tannery waste, chemical fertilizers, and sole application of tannery waste on soil and rice (Oryza sativa L.) plants. The results revealed that T3, which received high-quality vermicomposted tannery waste as an amendment, exhibited superior enzymatic characteristics compared to tannery sludge amended (TWS) treatments (T8, T9). After harvesting, vermicomposted tannery waste treatment (T3) showed a more significant decrease in PMs bioavailability. Accumulation of PMs in rice was minimal across all treatments except T8 and T9, where toxic tannery waste was present, resulting in a high-risk classification (class 5 < 0.01) according to the SAMOE risk assessment. Results from Fuzzy-TOPSIS, ANN, and Sobol sensitivity analyses (SSA) further indicated that elevated concentrations of PMs (Ni, Pb, Cr, Cu) adversely impacted soil-plant health synergy, with T3 showing a minimal risk in comparison to T8 and T9. According to SSA, microbial biomass carbon and acid phosphatase activity were the most sensitive factors affected by PMs concentrations in TWS. The results from the ANN assay revealed that the primary contributing factor of toxicity on the TWS was the exchangeable fraction of Cr. Correlation statistics underscored the significant detrimental effect of PMs' bioavailability on microbial and enzymatic parameters. Overall, the findings suggest that vermicomposting of tannery sludge waste shows potential as a viable organic amendment option in the near future.

Fire safe and sustainable lightweight materials based on Layer-by-Layer coated keratin fibers from tannery wastes

The increasing consciousness about the depletion of natural resources and the sustainability agenda are the major driving forces to try to reuse and recycle organic materials such as agri-food and industrial wastes. In this context, keratin fibers, as a waste from the tannery industry, represent a great opportunity for the development of green functional materials. In this paper, keratin fibers were surface functionalized using the Layer-by-Layer (LbL) deposition technique and then freeze-dried in order to obtain a lightweight, fire-resistant, and sustainable material. The LbL coating, made with chitosan and carboxymethylated cellulose nanofibers, is fundamental in enabling the formation of a self-sustained structure after freeze-drying. The prepared porous fiber networks (density 100 kg m–3) display a keratin fiber content greater than 95 wt% and can easily self-extinguish the flame during a flammability test in a vertical configuration. In addition, during forced combustion tests (50 kW m–2) the samples exhibited a reduction of 37 % in heat release rate and a reduction of 75 % in smoke production if compared with a commercial polyurethane foam. The results obtained represent an excellent opportunity for the development of fire-safe sustainable materials based on fiber wastes.

Isolation of chromium resistant bacteria from tannery waste and assessment of their chromium reducing capabilities – A Bioremediation Approach

Every year different industries generate numerous toxic environmental polluting agents throughout the world. Among the polluting agents, chromium (Cr) toxicity is a great concern nowadays. It is continuously released in soil and water, causing environmental and health problems thereby raising several public health issues in developing countries like Bangladesh. The primary goal of this study was to provide a bioremediation option to reduce toxic hexavalent chromium to a less toxic trivalent form by isolating chromium resistant bacteria from Cr contaminated environments. Bacterial isolates were obtained from seven tannery waste samples collected from Hazaribag and Hemayetpur, Savar, Dhaka. Twenty morphologically distinct colonies were screened, of which six showed the highest resistance. These were designated as A1, A2, B1, F1, K1, and P1. Their maximum tolerance to Cr (VI) was determined through growth assays in varying chromium concentrations up to 8000 mg/L on LB agar media. Strains A2 and B1 exhibited the highest resistances to chromium at 7700 mg/L and 7200 mg/L respectively. Bacterial strains A2 and B1 were identified through several biochemical tests and after PCR analysis finally identified as Bacillus sp. and Micrococcus sp. respectively. Their Cr (VI) reduction capabilities were assessed quantitatively using the diphenylcarbazide colorimetric assay. Both strains exhibit approximately 100% reduction of chromium from 100 mg/L concentration to non-toxic form within 48 h using accurate analytical methods. This study demonstrates the isolation of highly chromium-resistant bacteria from tannery waste that can efficiently bioremediate Cr (VI) pollution, thus providing an eco-friendly and cost-effective bioremediation approach.

The Potential Role of Chromophiles (Absorbtion) Fungi from Polluted Landfill by Tannery Effluent Challawa Industrial Estates Kano State of Nigeria

The release of unprecedented tannery effluents into the environment as industrial wastes is one of the major causes of environmental pollution. Tannery waste containing heavy metals are usually disposed in landfills and streams in Challawa industrial estate Kano. In the present study tannery effluent discharge soil (polluted landfill), undischarged soil (control) were collected from the surrounding areas of tannery industry. The soil and physicochemical properties were examined in-situ. A total of eleven fungi species were found in the soil. The most common fungal strains viz., Aspergillus niger, Aspergillus sp, Rhizopus nigricans and Penicillium sp were tested for tolerance against chromium sulphate. The degree of tolerance was measured by their mycelia growth length of each respective culture colony and it was compared with control containing no chromium sulphate. Among the isolated fungal strains of all locations, Aspergillus niger was the most tolerant against chromium sulphate. It exhibit strong radial mycelia growth length from 0-4.0% followed by Rhizopus nigricans and the least was obtain by Penicillium sp. Effect of pH and temperature on tolerance of fungal isolates at 1% chromium concentration using different substrates tested were so effective at pH 4-5 and 32oC respectively. These fungi have shown a high level of tolerance to chromium sulphate tested which makes them so attracted and potentially candidate for further investigations regarding their ability to remove metals from contaminated waste waters.

Unleashing the potential of leather waste: Biogas generation and cost savings through semi-continuous anaerobic co-digestion

Leather processing is notorious for generating substantial amounts of polluting and putrescible organic waste, usually ending up in landfills or incineration. This study aimed to assess the potential of biogas production, waste treatment efficiency, and energy and cost savings benefits when scaling up the anaerobic co-digestion of leather processing wastes. The study focused on three waste types: tannery primary sludge (TPS), leather fleshings waste (LFW), and tannery wastewater (TWW). Semi-continuous anaerobic digestion experiments were conducted using three bench-scale reactors (R1-R3) over five phases; phases I and II were the startup and stabilization. In phase III, with an organic loading rate (OLR) of 0.6 kgVS/m3/d, the R2 reactor achieved an average of 0.323 m3 methane/kgVS added/day. This performance surpassed the other reactors by 39.14% (R1) and 41.29% (R3). In phases IV and V, using TWW instead of tap water for substrate dilution at different ratios (25–100%) reduced methane yield by 3.32–11.73% compared to the reactor that used tap water. The study further revealed that a medium-sized anaerobic reactor treating tannery wastes could reduce electric energy consumption by 3.64% and thermal energy consumption by 5.20%. This showcases the energy-saving benefits of co-digesting tannery wastes rather than disposing them in landfills. Using tannery wastes instead of traditional disposal methods resulted in approximately 94.68% savings in electric consumption and 45.03% in thermal energy consumption. This study offers a promising approach for sustainable leather waste treatment, biogas production, and considerable energy and cost savings compared to conventional disposal methods like landfilling.

Leather Industry Waste Management for Architectural Design

The leather and footwear cluster in Tungurahua state has a main role in the country’s production chain, supplying 76% of the country’s tanned hides for the textile, footwear, and furniture industries, among others. The processes involved in leather tanning generate liquid, gaseous, and solid waste, the latter including the shavings from the leather trimming process, which, due to their composition and volume, are compressed and disposed of in sanitary landfills. Through Strategic Design and circular processes, as axes of change in production, new processes and strategies are established for the creation of products derived from the reuse of tannery waste; as a result, a decorative block is obtained for the design of architectural spaces with dimensions of 150 × 75 × 355 mm, 300 g in weight, and a compressive strength of 15.72 MPa. This is subjected to physicochemical tests for its validation.

Using tannery wastes in poultry feed: a matter of concern for safe poultry production in Bangladesh

Nowadays tannery waste is a matter of concern because if it used as livestock feed, it could cause health hazards to humans. Therefore, this study was conducted to know the generation rates, utilization, disposal method of tannery solid wastes (TSWs), and inclusion level of it into the poultry feed. Moreover, this study determined the physical and chemical parameters of interest including moisture content, crude protein (CP) levels, and the presence of heavy metals such as chromium (Cr) and lead (Pb) in the poultry feeds that were sold in the studied area. For these purposes, a field survey was conducted with twenty tannery industries. Broiler feed samples were procured from multiple farmers situated in the Savar area of Dhaka. The feed source was classified into two categories, namely registered and unregistered feed mills. According to the study, wet blue trimmings was generated in 3.84% that was used as an ingredient of poultry feed. In addition, 55% of tanneries landfilled their waste, while 30% of them sold it for poultry feed. The utilization of TSWs in poultry feed production in this country was limited to a maximum of 1.314% of the total annual production. Besides, the CP% was determined in the range of 24.24 - 13.32 % and 18.15 - 11.01 % for broiler starters and growers, respectively, where lower CP content was found only in unregistered feed mills. Trace amounts of Cr and Pb were identified in each of the feed samples at very low concentrations. In conclusion, it can be stated that the percentage of tannery solid wastes mixed poultry feed was generated in negligible amounts and the registered companies’ feed was found normal in all aspects of the quality tested in the study. Keywords: Broiler feed, Feed mill, Heavy metal, Physical quality, Tannery solid waste

Gelatin extracted from chromium (III) tanned leather waste for the synthesis of controlled release hydrogel

Chromium (III) tanned leather wastes were used to obtain gelatin, which was applied as a coating material for the synthesis of controlled urea release hydrogels. It was found that the hydrogel released its total urea content in 120 h in aqueous solution and that it promoted a significant difference in the growth of arugula seedlings. When compared with commercial gelatin, the hydrogels based on gelatin extracted from tannery waste had similar behavior, especially in the way urea was diffused to the external environment of the controlled release system, it can be characterized as a material of non-Fickian behavior during the swelling process and later, as a Fickian behavior, when it begins its process of degradation of the polymer matrix. In this way, this work demonstrates that it is possible to value a waste to obtain tools to promote a more sustainable agriculture.

Evaluation of the diesel engine behaviors of premixed hybrid biodiesel obtained from tannery waste fat and canola oil

Evaluation of the diesel engine behaviors of premixed hybrid biodiesel obtained from tannery waste fat and canola oil