Chromium recovery by membranes for process reuse in the tannery industry

Leather tanning is a wide common industry all over the world. In leather processing, water is one of the most important medium, almost 40-45 L water kg-1 raw-hide or skin is used by tanneries for processing finished leathers. The composition of tannery wastewater presents considerable dissimilarities in the concentration range of pollutants both of inorganic (chlorides, with concentration ranging from several hundred to over 10,000 mg L-1 Cl–; sulphate (VI), ammonium ions and sulphide ions, exhibiting concentration that ranges from tens to several hundred mg L-1) and organic (the COD value is usually several thousand mg L-1 O2). Throughout the years, many conventional processes have been carried out to treat wastewater from tannery industry: unfortunately, in this case, biological treatment methods give rise to an excessive production of sludge, whereas physical and chemical methods are too expensive in terms of energy and reagent costs. In this work, a membrane process based on NF membrane modules was adopted to treat the tannery feedstock after primary conventional treatment. In a first step, the determination of all boundary flux parameters, in order to inhibit severe fouling formation during operation, were performed. After this, experimental work was carried out to validate the approach. The target of water purification was reached, that is the legal discharge to municipal sewer system in Italy of 90% of the initial wastewater stream volume. This allows having an immediate cost saving of 21%. Moreover, the developed process leads to a second benefit, that is the production of 5% of the initial volume as a highly chromium-rich concentrate at no cost suitable to tannery process recycle and reuse. In this case, cost saving rates exceeds 40%. At the end, scale-up of the investigated process will be discussed from technical and economic point of view

Determination of the Concentration of Pb, Cu, Cr, Zn and Cd in the Waste Water(Effluent) Discharged from the Ethiopian Tannery

Waste water discharged from the industry were used for irrigation purpose in the vicinity of industrial area of Ethiopia Tannery.  The waste water discharged from the tannery industry were examined for its heavy metals (Cu, Zn, Pb, Cd and Cr).   For this purpose three samples of waste water from different Sites (Site 1, Site 2 and Site 3) along the channel of the tannery were collected and analyzed by flame atomic absorption spectrophotometry (FAAS).  The concentration of heavy metals in waste water discharged from the tannery industry were found that Cu 0.019-0.023, Cd 0.018-0.023, Cr 3.33-7.945, Zn 0.17-0.29 mg/L and Pb below detection limit of the instrumentation.The results are also compared with the levels of metals in the data from previous studies. Keywords: Tannery, Waste water, Heavy metals, Flame atomic absorption Spectrophotometry

バングラデシュにおける製革産業の発展と河川環境汚染に関する政治経済学的研究

東京海洋大学博士学位論文 平成25年度(2013) 応用環境システム学 課程博士 甲第309号指導教員: 濱田武士全文公表年月日: 2014-01-10東京海洋大学201

Model of Green Technology Adaptation in Small and Medium-Sized Tannery Industry

Green technology is an applied technology by industry to keep the process of sustainable development. This study aims to discuss the adaptation of green technology to reduce waste produced by the tannery industry. The method used in this article is data analysis approach from the research survey, which was followed by reviews of the causal relationship between model of green technology adaptation and Small and Medium-sized Enterprises (SMEs) of Tannery Industry in Sukaregang, Garut, Indonesia. The originality of this study focuses on adaptation pattern of green technology in small industry that encounter various resource limitations. The discussion findings showed that the adaptation pattern in the development of green technology for the Tannery Industry of SMEs need to consider the harmony with SMEs organization conditions, technological condition, and environmental influences. The significance of this study is to identify intervention patterns from the parties concerned with (stakeholders) to drive green technology in SMEs Tannery Industry

Heavy metals concentration in different processing operational waste water from tannery industry

An investigation was conducted to assess the concentration of heavy metals from waste water of tannery industry located at Hazaribagh area, Dhaka, Bangladesh. The total contents of Cr, Ca, Na, Zn, Hg, Mn and Ni were determined using Atomic Adsorption Spectroscopy (AAS) method which were followed by a wet ashing Digestion process. Average concentration of those heavy metals obtained from different operational section of Samina tannery industry were found 416.89, 628.03, 235.78, 3.912, 0.054, 20.952 and 3.106 mg/l for Cr, Ca, Na, Zn, Hg, Mn and Ni respectively. As recommended by the World Health Organization, the level of those heavy metals in the tannery effluent from different sections have been found highly contaminated and not suitable for irrigation purpose and harmful for environment.       Note: The pdf full paper of this article will be uploaded soon.     &nbsp

Assessing Financial Soundness of Tannery Industry in Bangladesh: An Empirical Investigation Using Z-Score

There are lots of techniques available for measuring the financial health of a business firm. But the Altman’s Z-score has been proven to be a reliable tool across contexts. Bangladesh tannery industry is a unique one because the industry earns $1 billion-a-year by exporting leather. The main objective of the study is to assess the fundamental financial health of this industry using Z-score model. All listed tannery firms are considered in this study and the observed period is from 2010 to 2014. The required information has been collected from the annual reports of the selected companies and from other sources. The study revealed that two firms, Apex tannery and Bata Shoe, are financially sound whereas other three are not in a good position. The findings of the study can be useful for the managers to take financial decision, the stockholders to choose investment options and others to look after their interest in the leather manufacturers of the country. Keywords: Tannery industry, Financial soundness, Prediction, Z-scor

Efficiency of electrocoagulation method to reduce COD, BOD and TSS in tannery industry wastewater: Application of the box–behnken design

This study intends to assess the removal efficiency of the chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total suspended solids (TSS) from raw tannery wastewater using electrocoagulation by aluminum electrodes as well as to determine the effects of its main operating factors. Therefore, the response surface methodology was applied through an experimental Box–Behnken design by considering the current intensity (I), treatment time (T), and pH levels as the factors. In addition, the BOD, COD, and TSS removal percentages were considered to be the response variables. The results indicate that the treatment time, current intensity, and pH level were significant for COD and TSS, whereas only the treatment time was significant at a confidence level of p-value < 0.05 for BOD. For COD, the optimal operating conditions were I = 3 A, T = 24 min, and pH = 8.4; for BOD, the optimal operating conditions were I = 3 A, T = 24 min, and pH = 5.5; and for TSS, the optimal operating conditions were I = 2.7 A, T = 19 min, and pH = 7.4. Under these conditions, removal efficiencies of 56.8%, 69.2%, 99.9% were observed for COD, BOD, and TSS, respectively. The results suggest that electrocoagulation is an effective method for removing the parameters under study; therefore, it is a viable alternative for reducing the pollution issues caused by the tannery industry

Isolation, Characterization and Heavy Metals Tolerance Indices of Indigenous Fungal Flora from a Tannery located at Challawa Industrial Estate of Kano State, Nigeria

Seven fungal species (Aspergillus niger, Aspergillus versicolor, Aspergillus flavus, Aspergillus fumigatus, Rhizomucor pusillus, Trichophyton equinum and Rhizopus oryzae) were isolated from the tannery effluent collected at a tannery industry located at Challawa industrial estate of Kano State, Nigeria. Aspergillus niger had the highest percentage occurrence frequency of 36% (31) while Trichophyton equinum had the least percentage occurrence frequency of 4% (5). Consequently, Aspergillus niger recorded the highest mean tolerance indices of 1.175, 0.830, 0.580, 0.780 and 0.630 while Rhizomucor pusillus had the least of the tolerance indices of 0.675, 0.375, 0.346, 0.450 and 0.255 for chromium, cadmium, manganese and lead respectively. Accordingly, furthermore the minimum inhibitory concentration (MIC) and biomass yield of the seven tested fungi isolates cultured in the presence of the five heavy metals used in this study showed different level of growth pattern. Hence the high resistant potentials and tolerance to the selected heavy metals exhibited by the fungal species isolated in this study is an indication that indigenous fungal floral isolated from tannery effluent if properly harnessed may offer a feasible solution to the serious environmental pollution problems associated with the presence of heavy metals in tannery effluent

Isolation and characterization of thermostable protease producing bacteria from tannery industry effluent

The  study is a search for potential thermostable protease producing strains from tannery industry effluent. Among nine protease producing strains screened, one was selected as promising thermostable protease producer and identified as Bacillus sp. The activity of the protease produced by this organism is stable up to 700C. The optimum yield was achieved after 48 hours of culture, at 600C with the pH 8.0. The desired protein was precipitated from the crude extract by using ammonium sulfate (70%) followed by dialysis and purified by Ion-exchange chromatography. The maximum protease activity was observed at 650C and at pH 8.0. Further investigation on structure elucidation to this purified protein  for industrial level exploitation is in progress