"Ion Ionescu de la Brad" University of Agricultural Sciences and Veterinary Medicine, Iași
Abstract
Effluents of textile dyeing
are characterized by intense colour,
chemical oxygen demand, suspended solids
and a variety of refractory matter, such as
heavy metals and nonionic surfactants.
Strong colours may reduce light penetration,
thus affecting the growth of plants and
having impact on invertebrate and other
forms of wildlife. There are a large number
of methods for dyes removal, such as
membrane separation, flocculation,
sonolysis, anaerobic biological treatments,
oxidative destruction via UV/ozone
treatment, photocatalytic degradation,
which have certain efficiency but their
initial and operational costs are so great.
Sorption is one of the several techniques
that have been successfully utilized for dyes
removal. A large number of materials have
been used as suitable sorbents for
decolourization of industrial effluents:
activated carbon (the most common but
expensive adsorbent), polymeric resins,
various low-cost adsorbents (agricultural
and industrial by-products, peat, chitin,
silica, fly ash, etc.) Our investigation
presented the preliminary results of the
study on modified ash, which has been
tested for its use as material with sorptive
properties in the recovery of dyes from
waste waters. The batch equilibrium of
reactive dye Brilliant Red HE-3B sorption
on industrial waste, based on ash was
investigated in order to explore its potential
use as low cost sorbent for wastewater dye
removal. The results indicated that the
sorption of tested dye depended on initial
dye concentration, sorbent mass, pH,
temperature and contact time. The sorption
of dyes increased with ash dose, dye
concentration and temperature increase.
Even if the sorption capacity of ash was
relatively small, ash could be used for the
removal of dyes from aqueous effluents
