Salt free preservation techniques Detailed studies on the Rationalization of chilling Process for hides and skins

Abstract

Curing is the process carried out for the temporary preservation of newlinethe hides and skins which are the basic raw materials for the leather industry newlineHides and skins are subjected to bacterial damage if left untreated beyond newlineSometime Hence they have to be preserved till the commencement of leather newlineprocessing in tanneries The most commonly used curing methods globally newlineare salt based ones using huge amount of common salt about newline40 50 for the preservation Salt based curing methods are very effective in newlinepreserving the skins and hides for long storage periods However these newlinemethods generate a huge amount of pollution loads in the form of total newlinedissolved solids TDS and chlorides during leather processing Salt used in newlinecuring contributes more than 40 to TDS and about 55 to chlorides in the newlinecombined tannery effluent The discharge limit for TDS is quite stringent in newlineIndia and particularly in the state of Tamil Nadu which accounts for more newlinethan 50 of the tanning activity in the country Tamil Nadu Pollution Control newlineBoard had fixed a stringent discharge norm of 2100 mg L for TDS as the newlinestate is a water starved one Currently the waste water from the soaking of newlinesalted skins and hides needs to be segregated and evaporated in specially newlineconstructed solar pans The constraints are the space available for newlineconstructing the solar pans and the efficiency is poor due to prevailing newlineclimatic conditions newline newline