I tested IR and conductivity for these agricultural runoff samples before and after batch adsorption, varying the solid-to-liquid ratio, the adsorbent particle size, and the contact time.
Results provided trends to understand how such factors affected the adsorption processes, but could not describe what was in the water.
The Index of Refraction (IR) is unique and specific for different solutions because “light travels at different speeds in different media [and] …when light passes from one medium to another at any angle other than 90˚, it not only changes speed, it also changes direction at the boundary between the two media.” (“Refractive Index Principle,” 2012) The IR is affected by the concentration of the solution being measured, with IR increasing as the concentration increases.
Because temperature affects IR readings, the temperature at the surface of the prism should be kept constant.
Many things can contaminate water sources, but this project focused on herbicides, fertilizers, and fungicides, which enter surface water from urban and agricultural runoff and percolate into groundwater from farm irrigation and urban lawn watering (“Managing Stormwater Runoff”).
Contaminants are documented at levels above accepted guidelines for safe drinking water (“Agricultural Chemicals”; “Understudied Fungicides”; “Study Confirms Glyphosate”; Biello), and may be carcinogenic or cause other problems for body systems (“Drinking Water Contaminants”).
This work was the baseline from which I planned research studying how contaminant concentration is affected by batch adsorption.
The research question is: Can agricultural waste be used to remove contaminants from water?
This project studied batch adsorption using agricultural wastes found locally in Arizona to evaluate their performance as adsorbents to remove chemical contaminants from water.
In the early stage of my research, I collected water from irrigation ditches alongside farms near my home.