Chapter 11, Problem 54SE

Coal-fired power plants used in the electrical industry have gained increased public attention because of the environmental problems associated with solid wastes generated by large-scale combustion (“Fly Ash Binders in Stabilization of FGD Wastes,” J. of Environmental Engineering, 1998: 43–49). A study was conducted to analyze the influence of three factors—binder type (A), amount of water (B), and land disposal scenario (C)— that affect certain leaching characteristics of solid wastes from combustion. Each factor was studied at two levels. An unreplicated 23 experiment was run, and a response value EC50 (the effective concentration, in mg/L, that decreases 50% of the light in a luminescence bioassay) was measured for each combination of factor levels. The experimental data is given in the following table:

		Factor		Response
Run	A	B	C	EC50
1	–1	–1	–1	23,100
2	1	–1	–1	43,000
3	–1	1	–1	71,400
4	1	1	–1	76,000
5	–1	–1	1	37,000
6	1	–1	1	33,200
7	–1	1	1	17,000
8	1	1	1	16,500

Carry out an appropriate ANOVA, and state your conclusions.