A continuous-flow mini-diluter system for toxicity testing

Abstract A space saving portable mini-diluter exposure system for testing early life stages of fish and invertebrates has been developed and successfully used both in the laboratory and on-site with single chemicals and with complex effluents. This gravity-operated system can also be installed in a compact, vented enclosure to permit safe testing of hazardous volatile chemicals. The mini-diluter test system has several additional advantages over other widely used dosing systems in that it: (1) uses small volumes of complex effluents and/or single chemicals which reduces the problem of removing hazardous material from the test system's waste water; (2) works well with waste containing suspended solids; and (3) can maintain normal operation for up to 10 h if the effluent headbox supply pump fails and up to 4 h if the diluent water headbox supply pump fails.