Water source and quality in leather industry

Water quality in leather industry
Classification according to source
1. Rain water
Of little importance for tannage, as it occurs only sporadically. However, as a medium, it has ideal characteristic for leather production as it is free of mineral substances, dissolved gases and impurities. When it is stored in a pond or come from rain stream it can carry dirt particle suitable for soaking.
2. Surface water (rivers, streams, lakes)
Besides different quantities of mineral matters of about it contains organic substance, suspended solids and microorganism. It shows considerable temperature fluctuations, depending on the climatic condition. In many cases purification, filtration or softening is required because impurities can stain in dyeing.
3. Sea water
Despite its high content of salt and mineral matters of about 4-6 ⁰ Be it can be used to some extent. Used for soaking, rinsing processes after the lime and for pickle floats which are discharged before chrome tannage is started. In pickling for preserving and then depickle with fresh water with low salt content.
4. Ground water
Mainly used in tanneries most common in Pakistan`s tanneries. Constant temperature of about 10-20 ⁰C is an advantage. High content of mineral are possible, depending on which strata the water has passed.