Performance of the freshwater shrimp Atyaephyra desmarestii as indicator of stress imposed by textile effluents

Abstract. Textile plants consume large volumes of water and produce a great amount of wastewaters, which can be important sources of toxic discharges in receiving environments. The objective of this study was to evaluate the acute toxicity of textile effluents on the freshwater shrimp A. desmarestii. A whole effluent toxicity test procedure was used to determine the aggregate toxicity of three samples taken before and after wastewater treatment in a textile mill. The following LC₅₀ − 48 h values (%, v/v) were calculated: Untreated effluent −29% effluent (sample 1), 22% effluent (sample 2), and 47% (sample 3); Treated effluent −73% effluent (sample 1), 74% effluent (sample 2), and > 100% (sample 3). Based upon acute toxicity units (TU_a = 100/LC₅₀), untreated effluent varied from toxic in samples 1 and 3 (2.00 ≤ TU_a ≤ 4.00) to very toxic in sample 2 (TU_a > 4.0), whereas treated effluent varied from no toxic in sample 3 to moderately toxic in samples 1 and 2 (1.33 ≤ TU_a ≤ 1.99). Despite some limitations and constraints related to innate variability of industrial effluents, our results suggested that A. desmarestii can be a promising and potential test organism for assessing toxicity of complex chemical mixtures.