ENVIRONMENTAL ASSESSMENT OF LAS ON THE AQUATIC ECOSYSTEM USING A SCALE-UP SYSTEM

Scale-up microcosm system consisting of producer, decomposer and preda tor was employed to assess effect of LAS on aquatic ecosystem. Effect of LAS was determined with not only population density but also chemic al data such as ATP, nutrients, pH and DO, etc. Microorganism-such as bacteria, algae, protozoa and micrometazoa in the microcosm system pro liferated and reached to stationary phase on day 16, In the stationary phase, values of biological and chemical factors were constant, suppo rting the dynamic equilibrium of scale-up microcosm No observed effect concentration (NOEC) of LAS on population density was less than 1.5 m g.1(-1). NOECs of LAS on ATP, DO and P/R (net photosynthesis/respirati on) ratio were less than 2.5 mg.1(-1). It was suggested that scale-up microcosm system was useful for environmental assessment because it co uld provide precise assessment of chemical substances based on biologi cal and chemical condition of ecosystem, (C) 1997 IAWQ.