Acute Toxicity Tests of Cassava and Rubber Effluents on the Ostracoda Strandesia prava Klie, 1935 (Crustacea, Ostracoda)

摘要

Acute toxicity of cassava mill and rubber processing plant effluent to the ostracoda Strandesia prava were evaluated. Cassava LD_(50) values for 24, 48 and 96 h was 0.4786,0.311 and 0.2818% effluent concentrations, respectively, while LD_(50) were 169.82, 346.74,446.68, 562.34 and 2754.23 min for 25, 12.5, 6.25, 3.125 and 1.5625% effluent concentrations, respectively. Rubber waste water LD_(50) values for 24,48 and 96 h wasl2.59,11.89 and 11.22% effluent concentrations, respectively. All were significant at p<0.05. Rubber LD_(50) was 239.88,794.33,1584.89 and 3548.13 min for 100, 50,25 and 12.5% effluent concentrations, respectively. Cassava mill effluent were more toxic than rubber processing mill effluent and caused ostracod mortality faster within short exposure time. Pretreatment of cassava effluent in holding tanks before discharge into the aquatic ecosystem would possibly reduce its toxic impact.