Problem Statement & Research Objectives

Here is my problem statement rough draft:

Current desalination research via solar membrane distillation (MD) shows a lot of promise in water treatment. However, the water recovery by an MD process is limited by the formation of inorganic species that blocks the pore of the membrane. Identifying the recovery limit of membrane distillation for a brackish O&G produced water, characterizing membrane fouling by inorganic species during the recovery process, and modelling the change in bulk solution chemistry during the water recovery process through equilibrium modelling will provide the necessary data required to find a prevention from or solution to the problem of inorganic membrane fouling. This will ensure that the MD process keeps up productivity over time.

Research objectives this summer:

Objective 1. Identify the recovery limit of membrane distillation for a brackish O&G produced water

1. Make an artificial brackish O&G water medium (completed).
2. Identify the recovery limit of MD for this brackish O&G water (completed).

Objective 2: Characterize membrane fouling by inorganic species during the recovery process

1. Run the system and take OCT images of the membrane throughout the membrane run (particularly when the system reach 2X, 2.5X, 3X, etc. This will facilitate the discussion).
2. Run the system and stop the experiment at different time points when the recovery reach 2X, 2.5X, 3X, etc). Take a sample of the feed and draw water solutions. Take out the membrane and dry it at room temperature.
3. Take surface SEM/EDX images of the fouled membrane at the different time points
4. Take cross-section SEM/EDX images of the fouled membrane, to see if we have crystals of salt in the pores
5. Quantify the concentration of inorganic species on the membrane by digestion of 1 cm² of membrane in nitric acid, followed by analysis by IC or ICP-MS.
6. In the bulk feed, can we quantify the size of the particles formed? (DLS?)

Objective 3: Model the change in bulk solution chemistry during the water recovery process through equilibrium modelling

1. Recreate the solution chemistry of the brackish O&G medium in Minteq.
2. Make different files for the medium composition at 2X, 2.5 X, 3X, 3.5X, etc, recreating the solution composition at different time points during the water recovery experiment.
3. Model the speciation of the medium at 60^oC, and identify the supersaturated compound at the different time points.
4. Run again the model but this time add the insoluble components to the model to quantify the % of precipitated solutes. Do for the different time points.
5. Plot the change in precipitated species (multiple graph/curves if multiple precipitated species) over relative concentration (2X, 2.5X, 3X, etc).

Any and all feedback on my problem statement is appreciated! 

Sky