Treatment of Water Containing Dyes Using Cellulose Aerogels

Abstract

In recent years, there has been an interest in the study of new methods for the removal of dyes from water due to its large-scale use in different industries, for example, for paper printing, textile, leather, pharmaceutical, food or technological applications. It is estimated that more than 700 thousand tons of about 10 000 different types of dyes are produced annually. Most of them are synthetic origin and can generate adverse effects, for example, teratogenic, mutagenic and carcinogenic action. Dyes are mainly applied in the textile industry, and they are usually classified into anionic (acid dyes), cationic (basic dyes) and non-ionic (disperse dyes) dyes. The direct discharge of dyes into the environment can cause various damages to plants and animals: dyes can block the penetration of sunlight, reduce the photosynthetic efficiency of aquatic plants and ultimately destroy the ecological balance of the aquatic ecosystem. This study determined the adsorption efficiency of congo red, methylene blue, rhodamine B and naphthol green B dyes used in textile industry by using the aerogel - an adsorbent synthesized from paper waste. Total carbon was selected as indicator of dye concentration in solution. An increase in fibre content from 3 % to 5 % contributes to the improvement of adsorption properties. The decrease in congo red concentration after an adsorption process was 31.0 % and 38.0 % respectively; the decrease in methylene blue was 2.49 % and 8.15 %; the decrease in naphthol green B was 28.04 % and 34.14 % and the decrease in rhodamine B was 1.28 % and 4.13 %.