Curing of hides and skins using sodium salt is a well-established and economical preservation technique worldwide.  But it contributes to generating a large amount of total dissolved solids (TDS) and increasing the salinity of water during leather processing which is a threat to the environment.  The current research is an attempt to preserve goat skin using mahogany (Swietenia mahogany) seed’s extract.  In real practice different percentages of mahogany seed extract were applied on raw goat skin and 3% (by weight of skin) of it showed best result.  To evaluate the preservation efficiency, related parameters of preservation viz. odor, hair slip, shrinkage temperature, moisture content, bacterial count etc. were monitored regularly for 30 days.  The obtained results were compared with conventional salt curing process.  The experimental trial showed efficiency in lessening TDS value and chloride content. The preserved goat skins of both trials were treated following conventional leather processing techniques and physical properties were studied. The discussed preservation method exhibited comparable result in every index.

Keratin is a highly specialized fibrous protein, which is found in feathers, hair, wool and nails. Bioremediation of these waste materials is an issue requiring serious attention regarding environmental concern. In the present research work keratin protein is extracted from poultry chicken feather which is now treated as valueless product of poultry processing plants. Although it contains high keratin protein content, this byproduct is dumped continuously into the environment without further treatment. Millions of tons of chicken feathers are produced every year from poultry industry of Bangladesh which disposed off into environment without any industrial treatment. This protein rich valuable byproduct can be recycled and utilized effectively which has great economic and ecological importance. In this study, alkali-enzymatic hydrolysis was done for the extraction of keratin protein from feather. Desired result was found in reflux condensation system which yielded 76.2% protein hydrolysate compared to conventional hot plate hydrolysis which was yielded 52.63%. Detection and concentration of protein were determined by Biuret and Kjeldahl methods respectively.

Leather tanning mainly depends on chrome tanning. A huge amount of basic chromium sulfate (BCS) is used in leather tanning. About 60–70% of BCS has been taken by leather and the rest of the amount is discharged as effluent and solid waste. In the Common Effluent Treatment Plant (CETP) of BSCIC Tannery Industrial Estate (Hemayetpur, Savar, Dhaka), the effluent which contained a high concentration of chromium is precipitated as solid chromium hydroxide with other elements which is called a chrome cake. Chrome cake is not exposed directly in the open space due to its toxic effect on human health as well as the environment. Human occupational experience distinctly indicates that, when inhaled, chromium compounds are respiratory tract irritants, resulting in airway irritation, airway obstruction, and lung, nasal, or sinus cancer. It is strongly suggested to extract Cr from the chrome cake before dumping it; otherwise, it will be a potential hazard to the environment. Herein, the chrome cake is characterized by inductively coupled plasma-optical emission spectroscopy (ICP-OES), X-ray fluorescence (XRF), UV-visible spectrophotometer, etc., and develops a method to separate chromium from chrome cake. ICP-OES and XRF analyses show that the total chromium contained in chrome cake is ∼17.45% and 20.7%, respectively. UV-visible spectrophotometer indicates that ∼0.04% of chromium is hexavalent. Afterward, chromium has been separated by using H2SO4 where the optimized concentration was found to be 7%. The separation efficiency of chromium from the chrome cake for optimized condition is obtained at ∼95%.

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