Leather Industry Waste Research Articles

Experimental studies on biodiesel production from leather industry waste fat and its effect on diesel engine characteristics

In this study, biodiesel was produced from the leather industry waste fat (LWFB), which is harmful to the environment and paid for its disposal. The methyl ester yield of the produced biodiesel was found to be 86.8%. LWFB was mixed with petroleum diesel fuel at 10% and 30% ratios and was named LWFB10 and LWFB30, respectively. The impacts of LWFB blends on a single cylinder four stroke cycle direct injection diesel engine operating characteristics were analyzed under different engine loads and speeds. The results showed that the LWFB blends began to be injected earlier than petroleum-based diesel fuel. The ignition delay was almost the same for all test fuels since the cetane number of LWFB is the same as the reference diesel fuel. The combustion duration of LWFB blends were shorter at all engine loads and speeds than diesel fuel. The peak values of cylinder pressure and heat release rate of LWFB blends were almost the same as the diesel fuel. It was noticed that the brake specific fuel consumption values of LWFB blends were higher than the reference diesel fuel at all engine loads and speeds and brake thermal efficiency was inversely proportional to brake specific fuel consumption as expected. It was also found that LWFB blends reduced smoke emissions but did not cause a significant change in NOx emissions.

A Facile Approach to Fabricate Dual Purpose Hybrid Materials for Tissue Engineering and Water Remediation

Creating hybrid materials with multifunctionality and robust mechanical stability from natural resources is a challenging proposition in materials science. Here, we report the scalable synthesis of hybrid collagen scaffolds using collagen extracted from leather industry wastes and sago starch derived from agro-industry. The hybrid scaffolds were incorporated with TiO2 nanoparticles and cross-linked with oxidized sago starch. The biocompatibility, thermal stability and antimicrobial property of hybrid scaffold enabled its application in burn wound healing demonstrated through albino rat models. The highly porous hybrid scaffolds are shown to be super-compressible, which is typically forbidden in materials of biological origin. We demonstrate that the hybrid scaffolds concurrently display both adsorption and absorption behavior in the removal of oil and dye molecules, respectively from contaminated water. This study paves the way for the development of novel multifunctional and shape recoverable hybrid materials specifically from renewable resources.

Collagen as a Potential Biomaterial in Biomedical Applications

AbstractCollagen, a biopolymer finds its application in the preparation of pharmaceutical products that are used in wound management, ophthalmic, orthopaedic and oral surgeries. This wide applicability is due its special properties such as biodegradability, biocompatibility, easy availability and high versatility. Collagen is isolated from various sources such as bovine skin, fish skin, chicken skin, skin waste of marine organisms, solid wastes of leather industry, short tendons of slaughtered cattle and bone. The isolated collagen from biological wastes is found to be cost effective due to the adaptation of simple methods for its isolation when compared with other commercially available biological macromolecules. The functional groups such as amino and carboxylic acid present in collagen helps in its modification that suits for various end uses which include wound healing, ophthalmic defects, drug delivery and tissue engineering applications. These beneficial properties impart uniqueness to collagen molecule among the available bio molecules.

Development of a flexible composite from leather industry waste and evaluation of their physico-chemical properties

Worldwide leather industry is known to cause high degree of pollution such as soil and water contamination. Dyed trimming, a leather industry waste, is often dumped near the industrial site and is used for land filling. Recycling of such industrial wastes for making useful products by substituting leather has been investigated and reported here. Flexible composite sheets were made from dyed trimmings only and also in combination with natural fibres in various blend ratios. Wastes from jute and cotton were used as sources of natural fibres. The composite sheets showed maximum tensile strength and breaking loads at 50:50 blend ratios of dyed trimmings and natural fibres. The ultimate tensile strength, elongation, double fold, bursting strength, density and water and oil absorption characteristics of the composite sheets were determined as per American Society for Testing and Materials and Indian Standard methods. The products, i.e. the composite sheets, and the starting materials, i.e. the dyed trimmings and jute and cotton fibres, were also characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. Energy-dispersive X-ray analysis of both untreated and treated dyed trimmings was carried out and the presence of chromium 2.54% in untreated samples was recorded but the sample treated with NaOH did not show the presence of chromium. The natural fibre significantly improves the mechanical strength and thermal properties of the blended composite sheets with the increase in flexibility. These flexible sheets possess higher physical strength as compared to leather and may be used as leather substitute for making apparels and goods.

Exploration of chrome shaving hydrolysate as substrate for production of dehairing protease by Bacillus cereus VITSN04 for use in cleaner leather production

Chrome shavings (chromium complexed collagenous waste scrapings), one of the major proteinous solid wastes of leather industry are posing a pollution threat. Recovery and reuse of protein component of the waste can prevent their disposal as landfills. In the present work, the collagen hydrolysate derived from chrome shavings was screened as an inexpensive protein source in comparison with agro based protein wastes for the cost-effective production of dehairing protease. The chrome shavings used in the study were obtained during processing of goat skins. Maximum enzyme production of 203 ± 0.07 U/mL by Bacillus cereus VITSN04 was observed with the formulated medium (pH 8.0) containing, 12 g/L of collagen hydrolysate from chrome shavings, 15 g/L of molasses, 3 g/L of K2HPO4, 2 g/L of NaCl and 0.04 g/L of CaCl2. Fluorescence spectral analysis confirmed that collagen hydrolysate stabilized the protease and prolonged its activity. The protease was purified with a yield of 88.1% using 22% (w/v) of 2-propanol and 14% (w/v) of K2HPO4 aqueous two phase system. The purification and activity of the enzyme was confirmed by native-polyacrylamide gel electrophoresis. The purification yield of protease with aqueous two phase system was much higher than that with ultrafiltration system. Thus, approach made in the present study provides an attractive option for recycling chrome shavings waste as a cheaper protein source in the production of dehairing enzyme for use in cleaner leather processing.

Biodegradable plant nursery containers from leather industry wastes

Novel biodegradable polymeric materials based on protein hydrolysate (Pr.Hyd), derived from waste products of the leather industry, and poly(ethylene glycol) diglycidyl ether (PEG) or epoxidized soybean oil (ESO) are obtained and their physico‐chemical properties and mechanical behaviour are evaluated. Different processing conditions and the introduction of fillers of natural origin, as saw dust and wood flour, are used to tailor the mechanical properties and the environmental durability of the product. The biodegradable products, which are almost completely manufactured from renewable‐based raw materials, look promising for several applications, particularly in agriculture for the additional fertilizing action of Pr.Hyd. To this purpose, tests are carried out to prove the feasibility of novel biodegradable pots and containers by investigating their functionality, their physico‐chemical and mechanical behaviour in standard and controlled experimental field conditions, and to follow the assessment of their biodegradation process during plants cultivation in the soil. POLYM. COMPOS., 39:2743–2750, 2018. © 2016 Society of Plastics Engineers

Optimization of Keratinase Production by Amycolatopsis sp. Strain MBRL 40 from a Limestone Habitat

Background: The class Actinobacteria accounts for a high proportion of soil microbial biomass and more than half of the bioactive compounds including antibiotics, immunosuppressive agents, antitumor agents and industrial enzymes such as keratinases. Keratinases are modern proteases that can valorise poultry and leather industry wastes and may find applications in prion degradation and treatment of neurodegenerative diseases. A wide diversity of bacteria, actinomycetes and fungi are known to be keratin degraders. Manipur, being a part of Indo-Burma Hotspot, might harbor a rich diversity of bioactive actinomycetes. The objectives of the study are: a) Isolation of new keratinolytic actinomycetes. b) Medium optimization by statistical approaches for keratinase production. Methods: A protease producing actinomycete strain from Hundung limestone quarry at Ukhrul, Manipur, India, was investigated for its keratinolytic activities. Optimization of keratinase production was done using statistical methods namely, Plackett-Burman Design (PBD) and Response Surface Methodology (RSM). Eleven (11) variables were screened using PBD. Results: The strain showed keratinolytic activity with keratin azure and chicken feather as substrates. Maximum keratinolytic activity was observed at 40°C, pH 7 and 48 h of incubation. Yeast extract, MgSO4, and corn flour were found to affect the response signal positively whereas glucose, CaCO3, K2HPO4, NaCl and soyabean meal had negative effects. Yeast extract, cornflour, and soyabean meal were further studied using RSM. A 2.3 fold increase in keratinase production was achieved in submerged fermentation after the use of statistical optimization methods. Conclusion: On the basis of biochemical properties and 16S rRNA gene sequence analysis, the strain was identified as Amycolatopsis sp. strain MBRL 40. Novelty of the work: There are meagre reports of keratinolytic bacteria from limestone biotopes. In addition, keratinolytic Amycolatopsis species are scanty in the literature. This possibly is the first report of a keratinolytic Amycolatopsis strain from a limestone habitat.

Green composites and blends from leather industry waste

Blends based on protein hydrolysate (PH), derived from waste products of the leather industry, and poly(ethylene-co-vinyl acetate) (EVA), were obtained by reactive blending and their physico-chemical properties as well as their mechanical and rheological behavior were evaluated. The effect of vinyl acetate content and of a transesterification agent added to increase interaction between polymer and bio-based components were investigated. Novel biodegradable polymeric materials for spray mulching coatings were also obtained from hydrolyzed proteins and end-functionalized poly(ethylene glycol) (PEG), which was used as crosslinking agent. These products, almost entirely obtained from renewable sources, represent a new type of biodegradable material which looks promising for several applications, for instance in packaging or in agriculture as transplanting or mulching films with additional fertilizing action of PH. POLYM. COMPOS., 37:3416–3422, 2016. © 2015 Society of Plastics Engineers

Adsorption Pollution Leather Tanning Industry Wastewater by Chitosan Coated Coconut Shell Active Charcoal

Abstract Besides having advantages, Chitosan as biosorbent has also disadvantages. . Chitosan is very soluble in low pH so it cannot adsorb Cr (total) at low pH. It is due to active site (amine group) of chitosan undergo protonation and its adsorption capability is easily influenced by anions in waters. The research studied use of chitosan coating active charcoal of coconut shell to increase adsorption capability of Cr (total), BOD, COD. This research was done to evaluate characteristic of liquid waste quality with IPAL or without IPAL and compare with Regulation of DIY Governor number 7/2010. It studied also effect of pH and Concentration of chitosan coating active charcoal as adsorbent on decrease in Cr (total), BOD, and COD concentration on liquid waste of leather tanning. The results indicate liquid waste of leather tanning industry with IPAL and without IPAL have exceeded quality standard of liquid wast e of leather tanning industry. ANOVA statistical test indicated Cr (total), BOD, COD are significant at 5% (p

Activated carbons from biocollagenic wastes of the leather industry for mercury capture in oxy-combustion

This study evaluates the capacity of a series of activated carbons obtained from leather industry waste to retain mercury. The behavior of these materials was compared in two simulated flue gas compositions at laboratory scale. The atmospheres were (i) a typical coal oxy-fuel combustion atmosphere and (ii) an O2+N2 atmosphere. The activated carbons displayed different behaviors depending on their characteristics and the gas composition. The best results were obtained for the activated carbon with the highest surface area and greatest amount of micropores, sulfur and acidity character, these results being comparable to those of an activated carbon impregnated with sulfur specifically designed for capturing elemental mercury. The highest level of mercury retention was achieved in a O2+N2 atmosphere. However, independently of the ability of these materials to capture mercury, their most interesting characteristic was their ability to oxidize mercury in an oxy-combustion atmosphere, since this would facilitate the retention of mercury in flue gas desulfurization units with the consequence that the risk of damage to the CO2 compression and purification units would be reduced or even removed.

ADSORPSI PENCEMARAN LIMBAH CAIR INDUSTRI PENYAMAKAN KULIT OLEH KITOSAN YANG MELAPISI ARANG AKTIF TEMPURUNG KELAPA

Chitosan has been used as biosorbent. In addition to having advantages, chitosan as biosorbent also has disadvantages. Chitosan is very soluble in low pH, so it cannot adsorb Cr (total) at low pH. It is because the active site (amine group) of chitosan undergoes protonation, and its adsorption capability is easily influenced by anions in waters. Therefore, this research studied the use of chitosan coating on active charcoal of coconut shell to increase the adsorption capability of Cr (total), BOD, and COD. This research was done to evaluate the characteristics of the liquid waste quality with or without Wastewater treatment unit (IPAL), and compare them with the Regulation of DIY Governor number 7/2010. It also studied the effect of pH and Concentration of chitosan coating on active charcoal as adsorbent on the decrease of Cr (total), BOD, and COD concentration in the liquid waste of leather tanning. The results indicate that the liquid waste of the leather tanning industry with and without Wastewater treatment unit (IPAL) have exceeded the quality standard for the liquid waste of leather tanning industry. An ANOVA statistical test indicated that Cr (total), BOD, and COD are significant at 0.05 (p < 0.05), with various pH influencing the decrease in Cr (total), BOD, and COD. The highest removal percentage resulting from the effect of chitosan concentration coating on active charcoal is obtained in adsorbent C (K3A1), with Cr (total) (91.9%); BOD (99.5%); and COD (98.47%).;

Novel Thermoplastic Materials from Wastes of the Leather Industry

Hydrolyzed collagen from leather industry is a natural polymer easily available at low cost and its use is not in competition with food industries or other main applications because it is a waste material and a by-product of the tanning process. In this work, polyethylene-collagen hydrolizate blends, at ratios of 100/0, 90/10 and 80/20, were processed using a blow film line equipped with a single screw extruder. Film blowing is a shaping technique used extensively to produce most plastics films and bags for packaging applications. The effect of processing parameters on the physical properties of blown films was investigated. The extruded films were characterized through mechanical testing, scanning electron microscopy, and thermal analysis. The manufactured films showed satisfactory mechanical and thermal properties, thus polyethylene-collagen hydrolizate blends appears as promising candidate for the production of innovative material suitable for production of thermoplastic items for applications in packaging and agricultural segments.

Biodiesel Production from Leather Industry Wastes as an Alternative Feedstock and its Use in Diesel Engines

Waste leather fat is produced by the leather industry in fleshing processing and discarded as waste. These wastes can be used as a potential feedstock for biodiesel production due to their considerable fat content. In this work, raw fleshing oil which is a fat-originated waste of the leather industry was transesterified using methanol in the presence of an alkali catalyst to obtain biodiesel. The obtained biodiesel was then used in a four-stroke and direct injection diesel engine to evaluate the biodiesel behavior as an alternative diesel fuel, at a constant speed under variable load conditions. Blends [20 and 50% (v/v)] of biodiesel with diesel reference fuel were tested too. The emissions test results compared with diesel reference fuel showed that diesel engine fueled by biodiesel emitted significantly lower opacity and gaseous emissions than the same engine fueled by diesel reference fuel, and with very similar performance. The obtained data indicated that biodiesel from leather industry wastes is promising as an alternative fuel for diesel engines, and can be used to substitute diesel fuel in terms of performance and emission parameters without any engine modification.

Pengaruh penggunaan lumpur limbah industri penyamakan kulit terhadap penyerapan krom pada tanaman sawi

The aims of research was to study the effect of contaminated soil with tannery industrial wastesludge, and absorption level of chromium by the green mustard. The experiment was carried out in Kayen, Sleman, Yogyakarta for 3 months. The form of a pot experiment using a full factorial design 2x3 and 2 additional treatments as a control was set out in Completely Randomized Design (CRD), using 15 units of pots as replicates. The first factor consists of two varieties of mustard, which is kailan (chinesse kale) and spoon mustard greens (pak choy green). The second factor consists of 3 doses of leather tanning industry waste, i.e 500 mg chromium/kg soil, 1000 mg chromium/kg soil, 1500 mg chromium/kg soil. Control treatment was the planting of two varieties of mustard without the addition of sewage sludge. Preparation of sewage sludge was carried out by mixing the sewage sludge into the planting medium consisting of a mixture of soil, compost and manure treatments in accordance with the treatment. Observations made by harvesting the plants at the age of 3 and 6 weeks after planting for the next shoots and roots of plants and chromium content of growing media was analyzed. The results showed that the accumulation of chromium in the roots of plants was greater than in the plant canopy for the two types of mustards either good harvested at the age of 3 or 6 weeks after planting, and the content of chromium in plant tissues of mustard as part of vegetable that generally consumed exceeds the threshold of human daily consumption (0,035 mg/kg daily consumption).

Development of Chromium(III) Selective Potentiometric Sensor by Using Synthesized Triazole Derivative as an Ionophore

A new poly(vinyl chloride) membrane based electrochemical sensor containing synthesized triazole compound, that is, bis‐(4‐N‐amino‐5‐mercapto‐1,2,4‐triazol‐3‐yl)alkane (BAMTA) as an electroactive material was prepared and investigated as a chromium(III) selective sensor. The optimum composition of the best performing membrane contained triazole, sodium tetraphenylborate (NaTPB), nitrophenyl octyl‐ether (NPOE), and polyvinyl‐chloride (PVC) in the ratio 10 : 2 : 50 : 38 w/w. The sensor exhibited near Nernstian slope of 19.8 ± 0.2 mV/decade of activity in the working concentration range of 1.0 × 10−5−1.0 × 10−1 M. It displayed a stable potential response in the pH range 3.4–5.2. The sensor exhibited a fast response time of less than 10 s and could be used for at least 6 weeks without any considerable divergence in potentials. The proposed sensor showed very good selectivity over most of the common cations including Li+, K+, Na+, Ni2+, Co2+, Cu2+, Sr2+, Ba2+, Cs+, Pb2+, Zn2+, Mg2+, Cd2+, Al3+, Fe3+, and La3+. It could be employed successfully for the determination of Cr(III) ion activity in electroplating and leather tanning industry wastes.

Identifying Microorganisms Able to Perform Biodegradation of Leather Industry Waste

Among the waste generated in leather processing, proteic and lipidic compounds are particularly dominant. Enzymes, like proteases and lipases, have an important role in biodegradation of collagen, keratin and fats in leather waste. Present investigation deals with isolation, selection and characterization of proteolytic and lipolytic microorganisms in order to perform biodegradation of waste from leather industry. The inoculum of microorganisms was sampled from old waste storage dump leather. The proteolytic microorganisms were isolated using screening method in presence of casein and gelatin substrate type, respectively. The microorganisms that secrete the lipolytic enzymes were isolated using medium that contained the Tween 80. These microorganisms identified by microscopic analysis can be used for improvement of waste leather biodegradation process.

Study on the Preparation and Properties of Collagen Fiber- Polyurethane Composite Film

Chrome-tanned collagen fiber is the major solid waste of leather industry which is difficult to biological degradation and would caused serious pollution to the environment. However, the collagen fibers as a natural biological polymer materials, has unique properties of surface reactivity that the other polymer materials are not available. In this paper, the composite film of chrome-tanned collagen fiber- polyurethane (PU) were prepared is owing to H2O induced phase separation, and measured water vapor permeability, permeability, mechanical properties and microstructure. The results showed that the composite film of chrome-tanned collagen fiber-PU have continuous porous structure, which can improve the water vapor permeability and permeability of film, but reduce the mechanical properties of film. Thermal gravimetric analysis (TGA) showed that the thermal effect of collagen fiber and PU did not change significantly, so composite of collagen fiber and polyurethane by H2O induced phase separation belongs to physical process. The result demonstrates that this composite film has continuous porous structure, and collagen fibers with unique properties of surface reactions, so this material have potential applications in many fields.

Present and prospective leather industry waste disposal

Present and prospective leather industry waste disposal In this paper general characteristics of the main leather industry waste regarding its amount reduction by thermal treatment have been presented. Both the tannery solid wastes and the sludge contain organic substances. Their energy value is more than 50% higher in comparison to hard coal (nominally 20 MJ/kg as dry material). Up to now, the considerable amounts of energy are not recovered; leather wastes are predominantly on landfill. Implementation of a comprehensive thermal method for tannery solid waste and sludge utilization can permit to solve the waste disposal problem by effective neutralization of all of the waste. Moreover, it should bring economic benefits associated with steam or hot water production and landfill tax avoiding. The study is oriented towards the practical application.

Vitrification: An alternative to minimize environmental impact caused by leather industry wastes

The main purpose of this work was the investigation of the immobilization of chromium ion present in the ash from the incineration of chromium-tanned leather shavings (ACS) by means of vitrified ceramic bodies. To achieve the immobilization samples were initially produced adding soda-lime glass to ACS. After that, new formulations were produced with the addition of pure oxides, TiO 2 and MgO, to the soda-lime glass and ACS sample. These samples were conformed by pressing and fired in an eletrical furnace, at temperatures of 750, 800, 950 and 1000 °C. The ceramic bodies were evaluated with respect to their physical properties and mineralogical composition by X-ray diffraction and energy dispersive spectroscopy (EDS) mapping. The chromium immobilization was characterized by leaching tests according to Brazilian Regulations (NBR 10005). The results confirmed the immobilization of the chromium ion within the allowed limits of Brazilian Regulations, NBR 10004 (5 mg/L), with the use of glass and vitrification/densification agents such as titanium and magnesium oxides.

Silsesquioxane 3-n-Propylpyridinium chloride: a new polymer for the potentiometric analysis of Cr(VI) in electroplating and leather industry wastes

A new polymer, silsesquioxane 3-n-propylpyridinium chloride (SiPy+Cl-), was used in the preparation of an electrode. The polymer coated graphite rod ion selective electrode for Cr(VI) was constructed and evaluated for the determination of Cr(VI) in samples of electroplating and leather industry wastes. This electrode exhibited a Nernstian response for Cr(VI) concentrations between 3.1<FONT FACE=Symbol>´</FONT>10-6 and 1.8<FONT FACE=Symbol>´</FONT>10-2 mol L-1 and a detection limit of 2.8<FONT FACE=Symbol>´</FONT>10-6 mol L-1 (0.15 ppm). The response of the electrode for Cr(VI) was fast (15 s) and the independent potential of pH in the range of 3.0 to 7.0. The selectivity coefficients for several anions showed that the electrode presents excellent performance. The sensor exhibits a shelf-life of 6 months with good reproducibility. Determination of Cr(VI) in electroplating and leather wastes using the sensor was successfully achieved.