Heavy Metal Concentration in Tannery Solid Wastes Used as Poultry Feed and The Ecotoxicological Consequences

Abstract

In Bangladesh, the tannery solid wastes are converted to protein-concentrate to be used as poultry feed, fish feed, and in production of organic fertilizers. Over the last several years it is a common phenomenon in the largest tanning area of the country, the Hazaribagh tannery area at the south-east part of Dhaka city. One of the major concerns of these activities is the heavy metals, especially chromium, used in the tanning processes. A total of 18 samples were collected to study the heavy metal status of protein-concentrate production in the tanning area at various stages from the source to the final product, and to compare this with the imported ones. The various types of solid waste processing for protein-concentrate production were covered in sampling, and along with the heavy metal status these processes were studied comprehensively. The maximum chromium content of the solid waste was found to be 3.2 %. The final products sampled at two different places contained as high as 2.49 % and 1.94 % chromium. Cadmium, lead, arsenic, and mercury contents of all samples were also determined. The detected maximum and minimum concentrations of these elements were found to be: 3.888 ppm and 0.991 ppm for cadmium, 30.114 ppm and 7.577 ppm for lead, 2.212 ppm and 0.099 ppm for arsenic, and 13.916 ppm and 0.166 ppm for mercury.

Bangladesh's Leather Industry

“…that, if released unregulated, impact heavily on the environment, contaminating soil, water, and air (Umweltbundesamt 2003). Kumar Bhowmik 2013; Azom et al 2012;Hossain et al 2007;Hasan and Chowdhury 2005). Although enforcement is poor, other south Asian countries (Pakistan, India) have managed to establish a Pollution Control Board to monitor and regulate the environmental contamination caused by tanneries (e.g.…”

“…Off-cuts of RHS 69 and wet blue leather are further processed as inputs to fish and poultry feed (see Hossain et al 2007), animal glue or cloth hardener, among others, instead of being chemically neutralised and properly disposed of (see Photos 3 and 4). In late 2012, neither BSCIC nor consultant A was aware of any official projects.…”

Hexavalent Chromium in Tannery Solid Waste Based Poultry Feed in Bangladesh and Its Transfer to Food Chain

“…EPA Method 7196A is the most applicable and reliable method for analysis of Cr (VI) solubilized in the alkaline digestate. It is highly selective for Cr (VI) and little interferences are encountered when it is used on alkaline digestates [9].…”

“…Then, five to ten minutes were needed to wait for full color development. Finally, an appropriate portion of the solution was transferred to a quartz one-cm absorption cell and its absorbance was measured at 543 nm in a Hach DR/4000 model UV-Visible spectrophotometer [8,9].…”

Isolation and Characterization of Chromate Resistant and Reducing Bacteria from Tannery Effluent of Chittagong, Bangladesh

“…The SCW is protein-rich and indiscriminately used to produce poultry and fish feeds, and organic fertilizer. It is reported that feed ingredients produced from SCW contained chromium at levels as high as 2.49% (Hossain et al 2007).…”