A microcomputer-interfaced continuous flow toxicity test system

Abstract

While continuous-flow tests for toxicity evaluation are preferable over static tests, their use has been limited due to problems associated with their operation. Fluctuations in toxicant concentrations during exposure periods requires frequent analyses and represent a drawback in conventional diluter systems. To reduce toxicant fluctuations and to maintain suitable water quality during long-term test periods, a low cost microcomputer-interfaced monitoring system (MIMS) was installed on a Benoit type serial diluter. The system monitored flow rates of test solutions and measured a number of water quality parameters.The MIMS system provided up-to-date information on whether the test was progressing well and indicated when diluter maintenance was needed. The MIMS interfaced diluter system performed well in long-term continuous-flow tests with minimal disruption and eliminated experimental failure.