Travel grant to attend 2012 Malaysia- Thailand Graduate Forum in Life Science, Food Sciences and Agriculture.

RAS experiment (October 12 till Jan 13)

Finally my real experiment started last October 2013 until January 2014. I had two treatments, RAS with and without algae. Each treatment had four replicates. the microalge were introduced three weeks after the experiment start. 

 

Microalgae beads were introduced 3 weeks after the experiment started.

The beads dissolved earlier than expected.

By random, four of the eight RAS were selected as treatment with algae

Mass production of microalgae beads

How to prepare beads (a very brief instruction).

1. Pour sodium alginate in water (3 percent sodium alginate from total volume of water)

2. Mix well until sodium fully dissolve. 

3. Put algae and mix well (3 percent algae from total volume of sodium alginate solution). As my algae is filamentous and clumping, it is quite challenging to mix the algae uniformly.

4. Drop the solution into calcium carbonate. You will see the drops hardened in calcium carbonate and become round beads.

Here I use two plastic containers with a flat bottom. We start with the lower container. Fill the container with calcium carbonate and put at slow stirring. For the upper container, punch a few holes with the size of 2 mm and stack it on the lower container. Then, pour the sodium alginate solution into the upper container. As soon as you fill the sodium alginate solution, it will drop into the lower container and form into round beads. 

The falling distance of the sodium alginate solution into calcium carbonate is important to make sure that a round bead can be formed

My beads

Colonial versus Filamentous algae culture in free suspension or immobilized in alginate beads

An experiment comparing growth and ammonium uptake of colonial and filamentous algae when culture in free suspension or immobilized in alginate beads took place from 1 September until 20 September 2012. In this experiment I wanted to investigate which of the two algae had higher growth and higher ammonium uptake. On top of that, I wanted to know whether these two algae would grow better if they were immobilized in alginate beads. The finding of the experiment was no significant difference was found between the microalgae on the growth and ammonium uptake. However, higher growth was observed when the algae were immobilized in alginate beads than when the algae were cultured in free suspension.

Day 1

Right- microalgae in free suspension culture; Left- microalgae immobilized in alginate beads (Day 1)

Algae immobilized in alginate beads (same amount of algae were inoculated in beads and free suspension flask)

Filamentous microalgae in free suspension (Day 1)

Day 16-Algae in free suspension

Day 16- Algae in beads

Day 16- Algae in beads

Control beads, filamentous algae in beads, and colonial algae in beads

Recirculation aquaculture system - in the making

These pictures show my recirculating aquaculture systems (RAS). The design of the RAS started  in June 2012. At the time the pictures were taken which was in January 2013, only one RAS was completely assembled for testing. When my supervisor, Marc visited me in January 2013, we tested the system together. He consulted me on what to improve and later approved that another seven RASs could be built according to the same design. The RAS consists of 1) 80 liters of  fish tank, 2) 34 liters of solid waste separator (hydrocyclone), 3) 14 liters of nitrification unit, 4) Two 14 liters of algae tank, 5) a sump, and the water flow according to the sequence of compartments mentioned. The cost of making eight RASs were about RM 15,000 which is equal to not more than EUR 4,000. Since I got help from many technicians to build this system, I save a lot for labour cost.

Flow of water (clock wise) - Fish tank (top left)--> solid waste separator or hydrocyclone (red basin)--> nitrification unit--> algae tank--> sump

Fish tank

Solid waste separator

Inside of solid waste separator. The solid waste separator works using a hydrocyclone concept. Solid waste coming into this basin flow in circular movement. Heavier particles will settle down and clearer water will move to its outlet. It is made of commercial plastic basin.

With my supervisor, Marc