Re-use of Cinnamomum camphora natural dye generated wastewater for sustainable UV protective and antioxidant finishing of wool fabric: Effect of Fe(II) sulfate

Abstract

Natural dyes owing to their ecofriendly and high biocompatibility make their way for wide spread use in textile industries. However, the process requires lot of dyeing auxiliaries (acid, alkali, metal ions, etc) of which lot of remain unexhausted during dyeing and are discharged as the wastewaters representing a dramatic ecological concern. So, present research work deals with an environmentally benign cleaner production procedure of re-using C. camphora natural dye generated wastewater over and over again for simultaneous coloration and development of UV protective and antioxidant wool fabric. Dyed fabric samples were characterized in terms of CIEL*a*b* and K/S values. Wash fastness characteristics were investigated according to ISO standards. Use of Fe2+ as mordant increases the color characteristics of dyed fabric samples owing to its strong coordinating interactions with dye molecules compared to the other mordants such as Al3+, Sn2+, etc. The use of same dyebath for 5 successive times was done in a systematic way via exhaustion method and the functionalized fabrics were characterized by SEM, FT-IR, and EDX techniques. The pH, conductivity, and COD values were recorded after every cycle. Using same dyebath for 5 times lead to a considerable reduction in COD and conductivity values, hence decreases the effluent level of generated wastewater. In addition, the dyed fabric achieved excellent UV protection and antioxidant properties with good wash fastness characteristics which could be developed to protective clothing in near future.