Chemical and toxicological properties of coal fly ash - University of ...

Table 22. The range of concentrations and recommended water quality levels for chemical constituents measured intest solutions of W2.Range ofRecommended waterChemical concentrations quality levels r2constituent (mg/L)a (m!mb Changec r CaAl 1 values in mg/L except pH.b~alues are MATES cited from Cleland and Kin'gsbury (1977) unless anothersource is indicated.CValues of r2 and r represent the results from mul tiple and simple l inearregression analyses of the relationship between mortal ity observed in the testsolutions of the extract and the concentrations of each chemical constituentmeasured in those test solutions.d~rom Quality Criteria for Water 1976 (U.S. EPA, 1976).The extract of 13, like that generated from W2, was very alkaline andrelatively toxic. The regression analyses indicated strong relationshipsbetween the final and initial pH and fish mortality (Table 23). Althoughthe range of values for the final pH regression was rather narrow, therewere 16 data points between the minimum and mximum pH values. The initialpli values were also elevated enough to cause mortality. Aluminum, As, andCa were present in concentrations that exceeded recommended values;however, probably only A1 was present at sufficient levels to be acutelytoxic.The extract generated From I7 was slightly acidic (pH < 6.7) when the LC-50determinations were calculated (Table 24). The extract was much less toxicthan those of W2 and 13; therefore, test solutions used to determine theLC-50 value did not require large dilutions. The high percentage ofextract in the test solutions (75 to 100%) and the lower pH resulted in