engleski

Toxcity Study of Organic Dyes Wastewater

Organic synthetic dyes represent relatively large group of organic chemicals, which are met in practically all spheres of our daily life. Many of these substances are considered as toxic. Over the past two decades, manufacturers and users of these dyes have faced increasingly stringent legal regulations promulgated to safeguard human health and the environment. To comply those requirements, the new technologies has been designed, specifically, to analyse and remove colour and priority pollutants from wastewater effluents and methodology of the cleaner processes has been applied to circumvent pollution problems by eliminating their source. The largest product group of the organic synthetic dyes is water-soluble reactive dyes, mainly used in dyeing of natural fibbers. World production of reactive dyes is forecast to grow. Wastewater originated from reactive dye processes is characterised by poor biodegradability, passing unaffected through conventional treatment systems. At higher concentrations, reactive dyes show toxicity by inhibiting biomass growth of microorganism in aerobic active sludge. The biological activities of dyes in wastewaters, can differ greatly in spite of their similar structure, so their toxicological properties cannot be generalised as referring to one group only. The toxic influences of individual substances should therefore be determined through the experimental work.The aim of this work was to determine the efficiency of flocculation process as a treatment method for toxicity decreasement of wastewaters containing certain reactive dyes. Values of parameters IC50, AOX, COD and BOD, before and after flocculation treatment, were compared.

Organic dyes; wastewater; toxicity

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