Utilization of wastewater of Merox unit for un-hairing of sheep skin

Document Type : Research paper

Abstract

In this work, the effluent of Merox unit of Kermanshah Oil Refinery was used for un-hairing (tanning) regional sheep skin in leather production process. Four main factors influencing the hair removal process were studied in three levels including: the weight percentage of sodium sulfide (0.2-2%), calcium carbonate (4-6%), temperature (25-45°C) and time (30-90 min). Design of experiments (Design Expert software) was conducted with four mentioned variables and their effect on un-hairing efficiency (response factor) was investigated. The results showed the highest efficiency (99%) was achievable under optimum conditions of highest level of variables, while the 63% efficiency was obtained using tap water (instead of wastewater) under similar experimental conditions (level of variables). Moreover, the qualitative characteristic of un-haired hide was the same in two experiments. Adding calcium carbonate had no significant effect on un-hairing due to high alkalinity of wastewater. Using wastewater, considering 2% content of sodium hydroxide, increased efficiency and decrease the needs for calcium carbonate and sodium sulphide significantly. Using wastewater of Merox unit in skin-tanning leads to a decrease in unpleasant effluents of oil refineries and therefore the needs for chemicals and raw water in leather production industry, and as a consequence a reduce in environmental pollution generation.

Highlights

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]1[ م. ملاردی، ف. کارگر بهبهانی (1387) "شیمی و تکنولوژی چرم"، انتشارات مبتکران، 191 ص.
 
]2[ ف. سینایی، ا. شهبازی (1392) "بررسی روش­های تصفیه پساب صنایع چرم­سازی"، اولین همایش ملی برنامه­ریزی حفاظت، حمایت از محیط زیست و توسعه پایدار، همدان، دانشکده شهید مفتح، 8 ص.
 
]3[ ح.ر. انصاری رنانی (1382) "مقایسه آزمایشگاهی اثر دو روش موزدایی با استفاده از سولفید سدیم و هیدروکسید سدیم بر خصوصیات پشم و صفات فولیکولهای پوست گوسفند"، پژوهش و سازندگی در امور دام و آبزیان، شماره 60، ص 56-64.
 
]4[ ح.ر. انصاری رنانی، ح.ر. باقرشاه (1390) "جداکردن پشم از پوست با روش شیمیایی و اثر آن بر کیفیت الیاف و پوست، تولیدات دامی"، دوره 13، شماره 1،ص 1-6.
 
5) Gutterres, P.M. Aquim, J.B. Passos, and J.O. Trierweiler (2010) "Water reuse in tannery beamhouse process", Journal of Cleaner Production, 18, 1545-1552.
 
6) Dettmer, M.A.Z Ayub, and M. Gutterres (2011) "Hide unhairing and characterization of commerical enzymes used in leather manufacture", Brazilian Journal of Chemical Engineering, 28, 373-380.
 
7) Valeika, K. Bedeška, V. Valeikienè, and V. Kolodzeiskis (2009) "An Aproach to cleaner production: from hair burning to hair saving using a lime-free unhairing system", Journal of Cleaner Production, 17, 214-221.
 
8) Rydin, M. Black, B.M. Scalet, and M. Canova (2013) "Tanning of hides and skins", Joint Research Center, European Integrated Pollution Prevention and Control Bureau, 290 p.
 
9) Sivasubramanian, B. Murali Manohar, andR. Puvanakrishnan (2008) "Mechanism of enzymatic dehairing of skins using a bacterial alkaline protease", Chemosphere, 70, 1025-1034.
 
10) Frendrup, and J. Buljan (2000) "Haire-save unhairing methods in leather processing", UNIDO, Regional programme for pollution control in the tanning industry in south-east Asia, p. 23-24, 37.
 
11) Genschow, W. Hegemann, andC. Maschke (1996) "Biological sulfate removal from tannery wastewater in a two-stage anaerobic treatment", Water Research, 30, 2072-2078.
 
12) Heidemann (1993) "Fundamentals of leather manufacturing", E. Roether KG, 649 p.
 
13) B. Choudhary, A.K. Jana, and M.K. Jha (2004) "Enzyme technology appliactions in leather processing", Indian Journal of Chemical Technology, 11, 659-671.
 
14) D. Quadery, Md.T. Uddin, Md.A.K. Azad, M.J. Chowdhury, A.K. Deb, and Md.N. Hassan (2014) "Development of hair-save unhairing method using organic thio compounds in pre-tanning stages of leather production", International Journal of Scientific & Engineering Research, 5, 376-382.
 
15) Jian, T. Wenyi, and C. Wuyong (2010)"Studies on the application of ultrasound in leather enzymatic unhairing", Ultrasonics Sonochemistry,17, 376-382.
 
16) W. Nazer, R.M. Al-Sa’ed, and M.A. Siebel (2006) "Reducing the environmental impact of the unhairing-liming process in the leather tanning industry", Journal of Cleaner Production, 14, 65-74.
 
17) D. Hobson (1986) "Modern Petroleum Technology", Part I. Wiley and Sons, New York, USA.
 
18) C. Thortensen (1976) "Practical leather technology", p. 284-288.340, Krieger,Florida, USA.
 
19) Gallego-Molina, J.A. Mendoza-Roca, D. Aguado, and M.V. Galiana-Aleixandre (2013) "Reducing pollution from the deliming-bating operation in a tannery. Wastewater reuse by microfiltration membranes", Chemical Engineering Research and Design, 91, 369-376.
 
20) Aravindhan, S. Saravanabhavan, P. Thanikaivelan, J. Raghava Rao, and B. Unni Nair (2007) "A chemo-enzymatic pathway leads towards zero discharge tanning", Journal of Cleaner Production, 15, 1217-1227.
 
21) C. Thortensen (1976) "Practical leather technology", p. 284-288.340, Krieger,Florida, USA.
 
22) Gallego-Molina, J.A. Mendoza-Roca, D. Aguado, and M.V. Galiana-Aleixandre (2013) "Reducing pollution from the deliming-bating operation in a tannery. Wastewater reuse by microfiltration membranes", Chemical Engineering Research and Design, 91, 369-376.
 
23) Aravindhan, S. Saravanabhavan, P. Thanikaivelan, J. Raghava Rao, and B. Unni Nair (2007) "A chemo-enzymatic pathway leads towards zero discharge tanning", Journal of Cleaner Production, 15, 1217-1227.