Tannery Waste Research Articles

Combination of Thermal, Hydrometallurgical and Electrochemical Tannery Waste Treatment for Cr(III) Recovery

A combination of thermal (500–750 °C in air) and hydrometallurgical (acidic) treatments have been applied to dried tannery sludge, resulting in the initial conversion of Cr(III) to Cr(VI) and its subsequent leaching as wastewater with high Cr(VI) concentration content (3000–6000 mg/L), presenting an extraction efficiency over 90%. The optimal electrochemical conditions for the subsequent Cr(VI) reduction with respect to acid concentration and acid kind were established by applying appropriate rotating disc electrode (RDE) experiments, using a glassy carbon (GC) electrode, and found to be equal or higher than 0.5 M H2SO4 (for the respective Cr(III) concentration range studied). The result from leaching Cr(VI) wastewater was further treated in small electrochemical bench-scale reactor for its conversion back to Cr(III) form, potentially reusable in the tanning industry. Ti-based anodes and a reticulated vitreous carbon (RVC) cathode were used to treat small (350–800 mL) samples in batch, as well as in batch-recirculation prototype electrochemical reactors, under the application of constant current or appropriately applied potential to achieve Cr(VI) conversion/reduction efficiency over 95%.

Tannery Wastewater Treatment by Coagulation-Flocculation Technique Using Combination of Calcium Polysulfide and Ferrous Sulphate

Effluents from the tannery industry have been a major source of environmental pollution. There is a need to evaluate the performance of wastewater treatment plant against regulatory standards. If in compliance found with standard, Employing appropriate treatment technique to meet the permissible discharge is important. In this reaction, performance evaluation of Tannery Wastewater and Treatment by coagulation technique of wastewater was investigated. Chemical oxygen demand (COD), Dissolved oxygen (DO), Total dissolved solids (TDS), Total suspended solids (TSS), chromium III and VI were the parameters selected to characterize the tannery waste water. From the characterization result of the factory effluent treatment plant it was found that; the factory effluent treatment plant meets the permissible discharge value in DO, Chromium III and VI. However, COD, TDS and TSS are far from the standards. Calcium polysulfide (CaSx) and ferrous sulphate (Fe(SO)₄) were the chemicals used for coagulation purpose. Treatment of 500ml original tannery waste with 400mg iron sulphate and variable calcium polysulfide concentrations (one, two and four v/v %) was conducted and characterized. From characterization result, 400mg iron sulphate and 20ml of calcium polysulfide treatment yields water that full fill the standard of discharge limit except for COD. In addition, at this treatment the best closer value of COD (1340mg/l) to the standard value (250mg/l) was found.

Assessment of the Tannery Wastes Impact in the Soil Properties of the disposal site In Sudan

The present study aims to examine chemical characteristics and heavy metal of tannery wastewater and sludge and to assess their influences on alterations in soil properties of disposal areas in terms of degree of heavy metal contamination and soil solution. Result revealed that soil layers exhibit greater values of soluble cations, anions, and electrical conductivity in tannery wastewater, sludge. Unlimited fluctuation in concentrations of heavy metals in soil profile was detected. Depending on estimated contamination factor (CF) and enrichment factor (EF), soil samples were found to be enriched and polluted with chromium. Simple correlation analysis showed significant progress between heavy metals and soil solution composition parameters. This proposes that both wastewater and sludge of tannery activities are accountable for altering properties of soil solution in term of chemistry and metal toxicity inducement into the soil atmosphere. Accordingly, tannery effluents, wastes, and sludge should not be allowed to be disposed into the environment without proper treatments.

Science Web-Module Integrated with Tannery Waste as Local Potential to Improve Students’ Problem Solving

Problem solving skills are very important skill students must owned. The low score of students’ problem solving skills becomes a serious problem in the 21 st century teaching and learning. The development of science web-based module integrated with tannery waste as local potential became a research that must be done. This research examined the appropriateness and the effectiveness of a science web-based module integrated with tannery waste as local potential in improving students’ problem solving skills. The Four-D research and development model was employed, consisting of define, design, develop, and disseminate. This research was conducted in the form of pretest posttest control group design. The appropriateness analysis conducted by content expert, teaching media expert, and science teacher indicating that the product was categorized very good. The effectiveness of the learning was tested using the independent sample t test with sig. value set at 0.000. The test showed that the science teaching done using the science web-based module was effective in improving students’ problem solving skills in SMP Negeri 1 Wungu. The product resulted from this study is expected to overcome the teaching and learning problems associated with the low score of students' problem-solving skills. Moreover, it can provide a real experience and independence to students in using the science web-based module to study.

Performance of Zea mays L. cultivars in tannery polluted soils: Management of chromium phytotoxicity through the application of biochar and compost.

Soil contamination with heavy metals caused by various industrial activities is a threatening global environmental issue of the current era. Chromium (Cr) is the most toxic heavy metal used in leather industry and disposal of untreated wastewater into natural water bodies leads to contamination of natural soil and water resources. We studied the combined effect of biochar and compost on improving the tolerance to Cr toxicity by enhancing the morpho-physiological and biochemical attributes of two maize cultivars (P-1543 and NK-8441) grown in tannery waste polluted soils. The results of this study reveal that Cr toxicity reduced the plant growth by affecting physiological and biochemical attributes. Here, compost and biochar application significantly increased the plant biomass (fresh and dry), height, photosynthesis, chlorophyll content, water relation, starch, and protein content over treatment set as control. However, significant decline in electrolyte leakage (EL), proline, lipid peroxidation, soluble sugars, and antioxidant enzymes (APX, GPX, GR, GST, GSH, SOD, and CAT) was observed by combined application of compost and biochar. Hexavalent chromium concentration was maximum decreased to 4.1μg g-1 in soil after post-harvesting of maize cultivar NK-8441, while in roots and shoots to 22.6 and 19.2μg g-1 of maize cultivar P-1543, respectively, by combined application of compost and biochar. Moreover, these both amendments in combination showed considerably better results than their sole application and cultivar P-1543 comparatively performed better than NK 8441, in both K and S soils. Correlation and principal component analysis (PCA) revealed mostly highly positive associations among all the studied morpho, physio, and biochemical attributes of maize plant with the few exceptions, particularly concentration of Cr(III) and Cr(VI) in soil. The present work concluded that combined use of biochar and compost has great potential to decrease Cr toxicity and improve plant growth in tannery polluted soils.

Assement of the migratory behaviour of contaminant originating from tannery waste water through amended clay liner using HYDRUS-3D solute transport model

Assement of the migratory behaviour of contaminant originating from tannery waste water through amended clay liner using HYDRUS-3D solute transport model

HEAVY METALS IN POULTRY AND FISH FEED INGREDIENTS IN BANGLADESH: A POTENTIAL THREAT TO OUR NEXT GENERATION

Hazaribagh the area of leather processing industries; is the main place of Bangladesh from where the poultry and fish feed have produced and supplied all over the country. Solid tannery waste and sliced- cut pieces of skin and hide are proteineceous. These wastes are converted to protein - concentrate to be used in poultry feed, fish feed and bio fertilizer without any appropriate treatment. Although total Chromium content in tannery waste based poultry and fish feed has been determined previously but no studies appear to have been on others heavy metals i.e. Zn, Pb, Cd, Ni, Mn and Fe. AAS is used to determine the heavy metals concentration in ppm. A total three types of sample were collected from different location of sampling site. The sample represents the various stages of protein - concentrate production from solid waste to final products i.e. poultry and fish feed ingredients. All heavy metals were not only detected in all sample type but also significantly higher than the MAC value for poultry and fish feed ingredients and cross the permissible limit for human.

A review of constructed wetland on type, treatment and technology of wastewater

The performance of constructed wetland depends upon the types of constructed wetland, vegetation, applied hydraulic load, and media used in the bed. This paper describes the review of constructed wetland on type, technology and treatment of various types of wastewater generated such as textile waste, dairy waste, industrial waste, piggery waste, tannery waste, petrochemical waste, municipal waste, etc. The review summarizes the types of constructed wetlands considering media, vegetation, removal efficiency, construction cost, maintenance cost and land area requirement using life cycle cost analysis. The review compares how and why constructed wetland is a better option as per treatment efficiency, their payback period and cost-effective with the other wastewater treatment technologies. Further, there is no proper guidelines for the selection of media and vegetation in the constructed wetland. It is found that Typha Latifolia and Phragmites Australis have a better removal efficiency than other species. Lightweight Expanded Clay Aggregate (LECA), saw dust, zero-valent iron and gravels can be effectively used as a media for the removal of organic matter, phosphorus, sulphate and arsenate. Constructed wetland with low Hydraulic Loading Rate (HLR) performs exceptionally well and can remove 80%–91% Biochemical Oxygen Demand (BOD), 60%–85% Chemical Oxygen Demand (COD) and 80%–95% Total Suspended Solids (TSS). It requires a very low operation and maintenance than others. This review on constructed wetland further suggests research and development related to land area, media, plants, engineering design and automation of treatment units. • Treatment efficiency of various types and technologies of constructed wetlands. • Performance of constructed wetland based on filter media and vegetation. • Comparison of wastewater treatment technologies as per life cycle cost analysis.

Studies on the efficacy of ultrasonication processes in combination with advanced oxidizing agents for alum pretreated tannery waste effluent

This study focusses on the efficacy of hybrid Ultrasonication (US) techniques for treatment of real tannery waste effluent (TWE). US treatment alone of raw TWE at an optimized amplitude of 40 % produced 20.32 % COD reduction, whereas hybrid US treatment with Fenton, H2O2, ozone and NaOCl oxidizing agents are not effective with low (11–25%) COD reduction. However higher COD removal was obtained by an alternative approach, by removing suspended matter from TWE through coagulation prior to hybrid US treatment. Alum gave higher removal than AlCl3 with COD and TSS reduction for an optimized dosage of 15 g/L. Hybrid US treatment of coagulated tannery waste effluent (CTWE) with H2O2, Fenton, NaOCl and ozone at their optimized conditions produced COD reduction of 36.82 %, 66.96 %, 35.94 %, 36.14 % respectively than 23.68 % for US alone. These hybrid US processes for CTWE exhibited good synergistic effects with coefficients varying from 1.2 to 1.67. US + Fenton was most effective to treat CTWE with highest increase in biodegradability as BI value of 0.39 increased to 0.57, maximum reduction of 66.96 % COD, 58 % TOC and 47 % BOD, at optimized dosages of Fe2+ at 4 g/L, H2O2 at 18 g/L with a synergistic coefficient of 1.2. US + Fenton had least energy requirement of 0.0005 kW h/mg COD as well as highest energy efficiency of 600 mg L/kWh and highest cavitational yield of 6.34 × 104 mgL/kWh. However, hybrid US techniques when compared to HC/ HC hybrid processes, exhibited lower cavitational yield, energy efficiency and COD reduction which is a disadvantage for large-scale real applications.

An innovative prototype furnace designed to produce activated carbon for removal of chromium from tannery waste

In recent years, the demand for energy is increasing due to increase in population, industrial and agricultural activities. India has most resources of renewable energy and a number of technologies have been developed to harness the energy resources. There is a huge potential to separate energy from agricultural waste using a suitable technology. The organic waste from various forms can be treated either by a biochemical or thermo chemical route. Biochemical conversion through anaerobic digestion results in the energy degradation. Thermo chemical conversion involves in the burning of waste to produce energy. The treatment method depends on factors such as quality, quantity, works and local requirement. Coconut shell and sugarcane bagasse are naturally occurring and abundant biomass which offers an economical solution for heavy metal removal. Heavy metals like nickel and chromium are main toxins which affects lives severely. The adsorption potential of activated carbon derived from a mixture of coconut shell and sugarcane bagasse has been studied for the removal of chromium from the tannery waste water collected from the Common Effluent Treatment Plant(CETP) atPallavaram, Chennai. The activated charcoal is prepared by designing a prototype furnace which accommodates large quantity of biomass and burnt in an inert atmosphere to produce activated carbon. This carbon material was collected and made into energy blocks as briquettes. These briquettes have been used as a filter bed to remove the heavy metals by developing a packed bed column experiment. Thus the experiment indicates that mixture of sugarcane bagasse and coconut shell works out as an effective adsorbent for the removal of chromium from tannery waste water.

In vitro microcosm of co-cultured bacteria for the removal of hexavalent Cr and tannic acid: A mechanistic approach to study the impact of operational parameters

Industrial wastes, for instance, tannery wastes are rich soups of resistant and bioremediation-potent bacteria. In the present work, Chromium (Cr) and tannic acid (TA) resistance bacterial strains were isolated from tannery effluent and identified as Bacillus subtilis (MCC 3275) and Bacillus safensis (MCC 3283) based on its 16S Ribosomal RNA homology. Hexavalent Cr is highly toxic and mutagenic due to its high mobility and reactivity. Whereas, TA is known to inhibit enzyme activity, substrate deprivation, and interaction with membranes and matrix-metal ions. The developed In vitro co-cultured microcosm of B. subtilis and B. safensis was able to remove Cr(VI) up to 95% and TA up to 23%. The bacteria cultures separately were able to degrade Cr(VI) to 88% by B. subtilis and 91% by B. safensis and TA up to 27%. Plackett Burman design (PBD) followed by Response surface methodology (RSM) was applied for the optimization of physio-chemical parameters. The optimized conditions for co-culture development were recorded as K2HPO4 = 0.2 g/L, MgSO4 = 0.2 g/L, NH4Cl = 0.5 g/L, glucose – 0.2 g/L, TA – 5%, Cr = 200 ppm, incubation period of 96 h, agitation speed of 110 rpm, pH = 5.0, temperature= 30 °C and inoculum size = 3%. Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) revealed the thorough mechanism of cellular uptake followed by degradation of Cr(VI) and TA. The efficiency of co-culture for other heavy metals was observed as follows: Zn 65%, Pb 63%, Cd 65%, and Ni 65%. Bioremediation using bacteria is an economical and environmentally better alternative to conventional remediation methods. The isolated bacteria are useful in the effluent treatment of tannery or related industries and in metal recovery in mining processes.

Kinetic Analysis of Sequencing Batch Reactor for the Treatment of Tannery Waste water

Kinetic Analysis of Sequencing Batch Reactor for the Treatment of Tannery Waste water

Probing the structural role of Cr in stabilized tannery wastes with X-ray absorption fine structure spectroscopy

The effective stabilization of tannery sludge wastes is explored using X-Ray Absorption Fine Structure (XAFS) spectroscopies. Solidification of the Cr-rich waste was realized via vitrification of the incinerated sludge with silica and flux agents. It is demonstrated that the effective reduction of Cr(VI) and the structural role of Cr are strongly modulated by the chemical composition of the waste. Eskolaite microcrystallites are embedded in the silica matrix of all vitrified samples and the extent of microcrystalline formation is strongly related to the glass basicity. Both Cr(VI) and Cr(III) species are identified, corresponding to Cr(VI)O4 glass formers and Cr(III)O6 network modifiers. The toxic Cr(VI) prevails only in the glasses with the highest basicity index and lowest waste content, nevertheless it is safely incorporated and immobilized in the silica matrix. However, the detected abundance of Cr(VI) increases glass basicity and as a result, glass polymerization is hindered. Thermal treatment, a process that leads to glass-ceramics transforms almost all Cr(VI) to Cr(III), while eskolaite formation is promoted concurrently. Nevertheless, microcrystalline growth proceeds mainly via depletion of Cr(III) from the silica matrix and not from the reduced Cr(VI); yet, Cr-removal from the glass matrix does not impair the chemical stability of the devitrified products.

Improved filtration for dye removal using keratin-polyamide blend nanofibrous membranes.

Dyes from industrial wastewaters represent one of the most hazardous pollutants as they are not effectively biodegradable. The present work is focused to study the novel properties of keratin-polyamide blend nanofibrous filtration membranes for treating wastewaters containing dye. Keratin protein was extracted from goat hair, a tannery waste through sulphitolysis process. The extracted keratin was blended with polyamide to prepare a nanofibrous membrane through the electrospinning process. The fabricated pristine polyamide and keratin-altered polyamide membranes were characterized and compared for their properties. Effects of solution pH, dye concentration, membrane flux, and membrane capacity have been examined. Very fine nanofibers and enhanced porosity drive the membrane to enhanced flux and higher filtration efficiencies. At pH 2, the dye removal efficiency of the blend membranes was 100, 99, 98, 90, and 83% for 100, 200, 250, 300, and 400 ppm concentrations of dye, respectively. The keratin-polyamide blend membrane exhibited better properties in all aspects. The results of this present investigation indicate that the presence of keratin in filtration membranes is promising for dye removal from the effluents.

Biotransformation of chromium (VI) by Bacillus sp. isolated from chromate contaminated landfill site

ABSTRACT A potent Cr (VI) resistant bacterial strain DHS-12(7) was isolated from tannery waste landfill site and identified as Bacillus sp. based on pheno- and genotypic methods. The maximum tolerable concentration (MTC) of Cr (VI) was found as 1000 and 250 ppm in nutrient-rich and minimal salt medium, respectively while significant variation of MTC and Cr (VI) reduction efficiency was observed in the solid and liquid medium. The complete reduction of 10 and 25 ppm Cr (VI) was recorded within 18 h and 24 h., respectively in the minimal salt medium and the reduction trend of the strain was bacterial growth-associated. The detection of almost invariable total Cr concentration and the presence of NADH-dependent chromate reductase activity in the cell-free extract, indicated the extracellular Cr (VI) reduction rather than intracellular uptake. Furthermore, chromate reductase (ChrR) gene was amplified, sequenced and the translated amino acid sequence of the ChrR gene showed a high degree of homology with chromate reductase of different organisms. Conclusively, the findings of the present study highlight that Bacillus sp. strain DHS-12(7) can be a potent bioremediation agent for detoxification of Cr (VI) from the contaminated environmental sites for ecological restoration.

THE REUSE OF INDUSTRIAL TANNERIES. ARCHITECTURAL HERITAGE IN GUIMARÂES, PORTUGAL

Abstract. The city of Guimarâes (Portugal) was designated a UNESCO World Heritage Site in 2001 and European Capital of Culture in 2012. From the 14th to the 19th century it was characterized by its Portuguese architecture using traditional construction techniques and materials, and known for its leather, metallurgical and cutlery industry. This study examines two former tannery factories dating from the 19th century, and occupying a sizeable portion of the historic centre of the city. They are located close to the Couros river, their main source of water, but also where the tannery waste produced by the tanks where the skins were tanned, is deposited. This text focuses on three main concepts - rehabilitation, reuse and sustainability - through the analysis of two historical moments. The first of these, the past, is viewed through a timeline of events recorded in plans, photographs, documents, and historical facts. A formal spatial comparison of these records and the present buildings shows how the present use of these spaces and their respective functionalities can be observed in parallel with the past. This before and after comparison shows a progression from industrial activities to a cultural valorization of an architectural, urban and environmental space, as well as the development of the industry in a new context evoking the collective memory of the place.

Removal and recovery of heavy metals from tannery sludge subjected to plasma pyro-gasification process

Chromium shavings are toxic waste produced by the tanning industry and include both liquid and solid materials contaminated with chromium(III). Their treatment by pyro-gasification in a plasma torch allows to convert them into an inert solid residue; unfortunately, the high temperatures involved in the process (∼1500 °C) induce the volatilization of some metals, the subsequent condensation of which leads to the formation of hazardous powders that require appropriate management. The aim of this work is to study the most convenient approach to deal with these powders, generated as a by-product when chromium-containing tannery waste is treated with plasma pyrolysis, and recover the heavy metals they contain. Initially, the best conditions were identified to extract those components (Pb, Zn and Cd) that can be leached from the powder, testing solutions of HCl and H2SO4 at various concentrations; subsequently, their recovery was studied considering different treatment strategies. Fractional precipitation by neutralization with 1M NaOH has proven effective for the selective recovery of Pb and Zn, followed by adsorption on chitosan for the extraction of Cd. Finally, an integrated process is proposed, which includes the two separation approaches mentioned above and allows a complete recovery of Cd and Pb, in addition to 96.3% of the initial content of Zn.

Isolation and Characterization of Electrogenic Bacteria from Tannery Wastewater

Electrogenic bacteria are able to transfer electrons to extracellular electron acceptors as well as can be used in devices like bioelectrochemical systems (BES). This study was focused to produce electricity from wastewater using microbial fuel cell and find out potential electrogenic bacteria from liquid tannery wastes. After power generation study, six isolates were screened as potential electrogenic bacteria. Of them, two potential bacteria were identified based on their morphological and biochemical characteristics and confirmed by phylogenetic analysis based on 16S rRNA gene sequence. We also investigated the effect of anode surface area on electricity generation in the microbial fuel cells and found that the surface area had positive impact on electricity generation.
 Bangladesh J Microbiol, Volume 37 Number 1 June 2020, pp 23-27

Electrospun Keratin-Polysulfone Blend Membranes for Treatment of Tannery Effluents

Due to the high toxicity of effluents radiating from tannery industries, there is a need for effluent treatment so as to limit its dangerous impacts on the environment. Fabricating responsive membranes is gaining significant interest in wastewater treatment applications. This study investigates the preparation, characterization, permeation, and antifouling properties of the keratin-polysulfone blend membranes. Keratin, a bioinspired material, is used as the responsive element along with the polysulfone matrix, which together acts as the responsive membranes for efficient filtration. Keratin was extracted from the goat hair, a tannery waste, through ball milling—an ecological, cost-effective, and time-consuming method. Keratin-polysulfone was blended in the ratio 95:5 (v/v) in their respective solvents to prepare nanofiltration membranes. The morphology of the membranes shows the random arrangement of fibers with the interstitial spaces. Contact angle measurements reveal that the keratin-polysulfone blend membranes are partially hydrophilic, which in turn resulted in good antifouling properties. Improved porosity of the fabricated membranes enabled good absorption capacity, and enhanced mechanical properties are an added advantage for the fabricated membranes. Since the membrane showed enhanced filtration property, the post-tanning effluents from the leather industry have been treated by the keratin-polysulfone fabricated membranes. The treated effluent showed a maximum percentage reduction in chemical oxygen demand (COD) and biological oxygen demand (BOD) concentrations of about 53% and 66%, respectively. The dye removal efficiency of the fabricated membrane is reported to be 76%. Thus, filtration efficiency has been established paving a way for treating effluents in an efficient way.

Formation and Immobilization of Cr(VI) Species in Long-Term Tannery Waste Contaminated Soils

Chromium speciation in naturally contaminated soils appears more complex than spiked studies have shown. This study characterized Cr speciation (oxidation states; availability; molecular geometry) intended to highlight the genesis of immobile Cr(VI) species in long-term tannery waste-contaminated soils. In a series of samples obtained from Shuitou in China, chemical extraction methods showed that Cr(III) was dominant(>96.7% of total Cr), with Cr(VI) concentration up to 144 mg kg-1. Of the total Cr(VI) present, immobile Cr(VI) represents >90%. Synchrotron-based X-ray near-edge structure spectroscopy (XANES) showed the occurrence of Cr(VI), which was not removed by phosphate buffer extraction, confirming a significant amount of immobile Cr(VI) fractions in soils. X-ray fluorescence maps exhibited the heterogeneous distribution of Cr in soils associated with both Mn and Fe. Such a distribution suggests Cr(III) oxidation to Cr(VI) by Mn oxides and a possible immobilization of both Cr(III) and Cr(VI) onto Fe (hydr)oxides. Linear combination fitting of XANES spectra revealed that fractional weights (%) in samples were CrFeO3 (49.3-53.6), CrOOH (22.3-30.8), and CaCrO4 (13.2-25.3). Our results demonstrate that (i) Cr(VI) is immobilized in soils and (ii) mechanisms of Cr(VI) immobilization are CaCrO4 precipitation and recrystallization with Fe (hydr)oxides.