Assessment of Phytotoxicity of Used Zeolite as a Sorbent of the Dyeing and Finishing Production Wastewater by the Phytoindication Method

Introduction. The optimization of the technological processes for dyeing textile materials using wastewater adsorption purification via natural zeolite is relevant. The purified water can be used as recycled water for reuse in fabric dyeing technology.Problem Statement. The used zeolite sorbent belongs to the by-products of the dyeing and finishing industry’s wastewater treatment process. However, there is possibility to reuse it as a secondary material resource after determining the level of toxicity.Purpose. The purpose of this research is to assess the phytotoxicity of spent zeolite as a natural adsorbent for the purification of wastewater from dyeing and finishing production of textile dyes and auxiliary substances by the methods of phytoindication to determine possible directions of its use without additional costs for its disposal.Material and Methods. Wastewater from dyeing and finishing production and spent zeolite are research materials and winter barley seeds are the phytotest object. The method of scientific information generalization has been used; chemical analysis of wastewater has been carried out by the method of optical emission spectrometry with inductively coupled plasma; the intensity of winter barley stalks growth has been studied by the method of laboratory phytotesting; phytotoxicity has been evaluated with the use of analytical expression.Results. The phytotoxicity of used zeolite on water, soil, and concentrated substrates does not exceed 20%, which indicates the absence or low level of its toxicity and the possibility of reuse. The phytotoxicity of the aqueous substrate (water extract) of the spent zeolite has a negative value (–6.67%), which indicates that the studied aqueous substrate is not toxic.Conclusions. The experimental assessment of the toxicity of the used sorbent has allowed reusing it in the field of road construction and in the production of building materials.