Toxicity of Uranium Adsorbent Materials using the Microtox Toxicity Test

In recent years many waterways in Slovenia have been subjected to an increased loading with pesticides due to intensification of agriculture. The most widely used herbicides are atrazine and alachlor and they were detected in some rivers and even in ground water. Therefore the effects of atrazine and alachlor on selfpurification processes were investigated. The basic selfpurification processes studied were biodegradation of organic substances and photosynthesis and growth of algae. The inhibiting effect of pesticides on the process of biodegradation of organic pollutants was evaluated by the use of laboratory river model and mathematical modelling. The harmful impacts of pesticides on aquatic autotrophic organisms were assessed by measurement of net assimilation inhibition (24-h acute toxicity test) as well as growth inhibition - chlorophyll- a content (72-h chronic toxicity test) of algae Scenedesmus subspicatus. The results obtained demonstrate that atrazine and alachlor in concentrations found in our rivers have practically no effect on biodegrading heterotrophic organisms, while their adverse effect on algae is quite considerable.

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Microtox evaluation of industrial wastewaters

Water Science & Technology ◽

10.2166/wst.1994.0516 ◽

1994 ◽

Vol 30 (10) ◽

pp. 97-106 ◽

Cited By ~ 7

Author(s):

Cheng-Fang Lin ◽

Oliver J. Hao ◽

Fu-Tien Jeng

Keyword(s):

Treatment Process ◽

Antagonistic Effect ◽

Industrial Wastes ◽

Activated Sludge Process ◽

Industrial Parks ◽

Close Relationship ◽

Microtox Assay ◽

Microtox Toxicity ◽

The Individual ◽

Final Effluent

The main purpose of this study was to establish an inhibitory database using the Microtox assay for different wastes. The waste samples included 19 pretreated industrial wastes from two different industrial parks, 11 other industrial wastes outside industrial parks, and different treatment process effluents. The following is a brief summary of the findings from this study: (1) COD and BOD had a close relationship among different wastes; (2) Microtox data did not correlate with the conventional parameters of BOD, COD and SS; (3) many wastes did not meet the pretreatment standards and exhibited high Microtox toxicity; (4) some wastes exhibited high Microtox toxicity, although they met the pretreatment standards; (5) the mixture of the individual wastes exhibited an antagonistic effect; (6) the activated sludge process removed 60-75% of influent toxicity; and (7) the final effluent sometimes showed an increase in Microtox toxicity.

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