Lesson 6 - BiobasedMaterials for water treatment

Question 1

Types of nanocellulose

Answer 1

Cellulose nanofibers (CNF) and cellulose nanocrystals (CNC)

Question 2

Properties of Nanocellulose

Answer 2

High surface area, easily functionalized, strong mechanical properties.

Question 3

Applications of nanocellulose

Answer 3

Used in membranes, adsorbents, aerogels, and hydrogels for water purification.

Question 4

Advantages of nanocellulose

Answer 4

Renewable, biodegradable, and can be tailored for specific contaminants.

Question 5

Key mechanisms for adsorbents

Answer 5

Ion exchange, chemical bonding, electrostatic attraction

Question 6

What membrane structure is most common?

Answer 6

Membrane structure often consists of a thin, dense active layer supported by a more porous sublayer.

Question 7

Key differences between filters and membranes

Answer 7

1. Membranes are typically thinner and have more precise pore size control compared to filters.
2. Membranes often operate based on surface filtration, while filters rely more on depth filtration.
3. Membranes can generally remove smaller contaminants compared to filters.
4. Filters often have higher throughput but lower selectivity compared to membranes.

Question 8

Low cost adsorbents

Answer 8

1. Natural materials,
2. Agricultural waste/by-products,
3. Industrial wastes/by-products

Question 9

Examples of natural material for adsorbents

Answer 9

1. Wood
2. Coal
3. Peat
4. Chitosan
5. Clays
6. Natural Zeolites

Question 10

Examples of agricultural wastes/ by-products

Answer 10

1. Straw
2. Sawdust
3. Shells, hulls, stones from fruits and nuts
4. Corncob waste
5. Sunflower stalks

Question 11

Examples of industrial wastes/ by-products

Answer 11

1. Fly ash
2. Blast furnace slug and sludge
3. Bagasse
4. Palm oil ash
5. Shale oil ash
6. Red mud

Question 12

What can be used to recover oil spill on water

Answer 12

Aerogels and gelators

Question 13

What kinds of mesh can be used to separate oil from water?

Answer 13

1. Superoleophobic
2. Superhydrophobic
3. Superamphiphilic

Question 14

What does CA stand for?

Answer 14

Cellulose acetate

Question 15

Benefits of Cellulose acetate membranes

Answer 15

1. Excellentfilm-forming property
2. Highchemical and mechanical stability
3. High hydrophilicity
4. Eco-friendly
5. Suitable cost

Question 16

What is the main technique for the preparation of Celluloce acetate based membranes?

Answer 16

Phaseinversion technique.
By changing the phase inversion conditions such as:
1. CA concentration,
2. Solvent type
3. Coagulation bath temperature
4. The addition of different additives to casting solution

it is possible to prepare membranes with different pore sizes, morphologies, and applications