IOSR Journal of Pharmacy and Biological Sciences (IOSRJPBS) ISSN : 2278-3008 Volume 2, Issue 2 (July-August 2012), PP 36-45 www.iosrjournals.org www.iosrjournals.org 36 | Page Recovery of Chromium from the Tannery Wastewater by Use of Bacillus Subtilis in Gujranwala, Pakistan 1* Shazia Shafaat Adeel, 1 Amina Wajid, 1 Shahzad Hussain, 1 Farnaz Malik, 1 Zumra Sami, 1 Ikram Ul Haq, 2 Abdul Hameed, 1 Rafiq A Channa 1 National Institute of Health, Islamabad-45500, Pakistan 2 Department of Microbiology, Quaid-i-Azam University Islamabad, Pakistan Abstract:Tanneries discharge wastes without any treatments on the vast areas of vacant land around them. Untreated effluents contain toxic materials like hexavalent chromium and sulphides which accumulate in soils and cause many health hazards. Hexavalent chromium is toxic and carcinogenic and is being extensively used in the tanning industry of Pakistan. The tannery wastewater samples were collected from two tanneries in Gujranwala, Pakistan. Chromium in these samples was determined using fractionation technique, spectrophotometry and MIBK extraction procedure. These samples were analyzed to recover chromium and chrome cake was purified using chemical treatment which can be used in recycling process. Enzyme was used to recover chromium from the samples. Two strains S 1 and S 2 of the Bacillus subtilis (isolated and identified from soil and tannery wastewater respectively) were used for enzymatic processing. Isolates were screened for extracellular protease activity. The strain S 2 of the Bacillus subtilis showed maximum zones of hydrolysis (2.3cm) and proteolytic activity of 107 PU/ml at 65 0 C temperature, 150 rpm agitation speed and7.5 pH on Shake Flask Fermentation. The One-step and the Two-step methods were employed for chromium recovery using the S 2 strain of the Bacillus subtilis. From the One-step method 96% chromium was recovered from sample-A and 92% from the sample-B. From the Two-step method of chromium recovery 98% of chromium was recovered from the sample-A and 97% from the sample-B. This paper evaluates the alternative treatment options used to treat, recover or recycle chromium from the waste water in order to minimize the environmental pollution. Key words: Bacillus subtilis, Chromium, One Step and Two Step Methods, Pakistan, tannery wastewater. I. Introduction Environmental pollution has been a foremost irritation to industrial development. Chemical-based industries are the prime targets of the environmentalists for their battle against pollution. The leather sector of Pakistan is one of the oldest sector. It has an established share in world market for tanned leather, leather garments and leather gloves. At present there are 720 tanneries in Pakistan which generated the exports of US $ 01 billion in year 2008-2009. The wastewater as result of tanning process is an important source adding Cr pollutent to the environment which causes many health hazards to all sort of life. The pressure by the environment protection agencies is so that it has become a common occurrence that the tanneries are forced to close down not only in developed countries but also in the developing countries. Chromium (III) salts are the most widely used chemicals for tanning processes, but 60% - 70% of total chromium salts reacts with the hides. In the other words, about 30%-40% of the chromium amount remains in the solids and liquid wastes (especially spent tanning solutions). One ton of wet salted hide yields only 200 kg of leather, but more than 50m 3 of waste water [1&5]. Therefore, the removal and recovery of the chromium content of these wastewaters is necessary for environmental protection and economic reasons. Since the untreated effluents contain toxic materials like chromium and sulphides which accumulate in soils and cause many health hazards. For instance, according to an official report of the Environmental Protection Department Punjab (1997), the drinking water supplied by the municipality in Kasur (Pakistan) was found polluted with a high level of chromium. The diseases found, among the workers of tanning industry and residents of Kasur, were skin irritation, diarrhea, heart burning, respiratory tract infection, severe cough, fever and loss of eyesight. Lung cancer, high blood pressure, and kidney failure were the reported causes of death in many cases [36] . National Toxicology Program (NTP) study, inspected and observed the mid-term toxicity of chromium VI to rats and mice. The test animals were injected sodium dichromate in their drinking water for 3 months, and as result focal ulceration, metaplasia, and hyperplasia of the glandular stomach were found on both rats and mice. histiocytic infiltration of liver, duodenum, and pancreatic lymph nodes was also detected. Rats also showed an increase in lung and spleen weight and in macrophage activity [25] . Thus leather industry is pressurized to look for cleaner options. The effluents of these industries contain chromium at concentrations ranging from tenths to hundreds of milligrams per liter [6] . The current activity indicates that the trend is more towards design and utilization of cleaner and safer technologies