Abstract:
The effluent water of many industries, such as textiles, leather, paper, printing,
cosmetics, etc., contains large amount of hazardous dyes. There is huge number
of treatment processes as well as adsorbent which are available for the
processing of this effluent water-containing dye content. The applicability of
naturally available low cast and eco-friendly adsorbents, for the removal of
hazardous dyes from aqueous waste by adsorption treatment, has been
reviewed. In this review paper, we have provided a compiled list of low-cost,
easily available, safe to handle, and easy-to-dispose-off adsorbents. These
adsorbents have been classified into five different categories on the basis of
their state of availability: (1) waste materials from agriculture and industry, (2)
fruit waste (3) plant waste, (4) natural inorganic materials, and (5) bio
adsorbents. Some of the treated adsorbents have shown good adsorption
capacities for methylene blue, congo red, crystal violet, rhodamine B, basic red,
etc., but this adsorption process is highly pH dependent, and the pH of the
medium plays an important role in the treatment process. Thus, in this review
paper, we have made some efforts to discuss the role of pH in the treatment of
wastewater.
