Soru

A geochemist designed an experiment to evaluate the adsorption capacity of engineered biochar for lead ($Pb^{2+}$) ions in contaminated synthetic groundwater. In a series of experimental trials, the researcher systematically set the solution pH to different specific levels ($4.0$, $6.0$, and $8.0$) to observe its direct effect on heavy metal removal. After a $24$-hour equilibrium period, the scientist measured the final concentration of adsorbed $Pb^{2+}$ ions remaining on the biochar surface. Throughout all trials, the initial $Pb^{2+}$ concentration ($50\text{ mg/L}$), mass of biochar ($0.50\text{ g}$), vessel volume ($100\text{ mL}$), ambient temperature ($25^\circ\text{C}$), and agitation speed ($150\text{ rpm}$) were held strictly constant.

Match each experimental component listed on the left with its correct variable classification on the right.