OWL - Organic Waste Liquidator [ PART 1 ]

OWL - Organic Waste Liquidator

FEEL FREE TO USE THIS DESIGN AND PROCEDURE FOR NON COMMERCIAL APPLICATION

I have christened the device the OWL.

Kitchen waste disposal is often a problem. There are methods of making compost out of the organic waste which could become a really messy affair and requires substantial amount of space. This is of course an excellent method of producing organic fertilizer but is not always ideal for small spaces. So I thought I would develop something that could be used in urban homes without the mess and the smell.

Caution: do not add citrus waste into the liquidator [ lemon, orange etc..]

If you want to skip the literature and head straight for the construction head for the title : Construction

The evolution of the idea:

I have an aquaponic  system [ growing fish in tanks and pumping the water into vegetable growing beds above and draining it back into the fish tank ] where I grow my vegetables. About a year ago I had introduced  an organic waste digestion system  into this. This was a rather simple technique. One of the growing bed's had a container with holes drilled at the bottom. The container had gravel to about 1.5 inch, covering the height of the hole ; the height of the container was 1 ft. Every day the lid was opened and kitchen waste was dumped into this container. The aquaponic system is an ebb and flow system which means that the growing bed fills with water from the fish farm and is flushed out according to a pre-programmed cycle. So each time this happens the container fills with water and flushes out filtering the liquid through the gravel. I noticed amazing improvement in the growth rate of vegetables and a substantial improvement in output and taste. 

In an aquaponic system bacteria like Nitrosomonas and Nitrobacter convert the ammonia produced by the fish into useful nitrate through the nitrogen cycle, which is manure for the plants. These bacteria develop in the growing media naturally over a period of six months to one year. 

I noticed that the rate of decomposition in my test container was so rapid that even after a period of six months the container was only 3/4 full and stayed that way. When organic waste decays a percentage of ammonia is also produced, the quantity is more in anaerobic systems. So I reckoned there were two primary groups of bacteria , one the bacteria responsible for the nitrogen cycle [ producing nitrates in the container ] and the other group, similar to the ones in bio-gas units, was responsible for the decomposition of the solid mass into fluid. The primary difference here was that the bio-gas was an anaerobic where as here it is mostly aerobic.

Taking it out of the Aquaponic System:
I thought it would be good if I could replicate the same outside the system as a stand alone device. Since the system was going well in the aquaponic medium it was a safe bet to assume that the bacterial action has stabilised/matured to a degree of perfection. So I prepared a container outside the system, this time a regular container without holes at the bottom. I then added vegetable waste from the kitchen into the container and then the key ingredient, a portion of the content from the container placed in the aquaponic system. I went for a 50/50 propotion of kitchen waste to the aquaponic container mass. More waste was added on a daily basis and to my delight the container was not filling up beyond a certain level. I noticed a substantial amount of liquid form at the bottom of the container. So I strained a little out, leaving some , making sure not to dry the container. The strained liquid was then used on a test batch of potted plants. I had five pots that was observed with and without the liquid treatment. Over a period of two weeks the pots with the liquid treatment showed rapid growth and darker , bigger green leaves.

Delighted with the results I set out to construct the OWL - Organic Waste Liquidator.

Construction:

These are the key points that I considered :

• A moderately sized container with a lid.
• A tap that can be fixed near the base of the container.
• Gravel to act as a filter.
• Maintaining safe liquid level after filtering out the liquid.

It is important not to drain out the entire liquid from the chamber as it contains the bacteria that aids the process. So the tap is fixed at a height of 2 inches from the base.

Select a contained based on your requirement. For a family of four a container of 15 inch height and 12 inch diameter would suffice. 

Use a drill to drill a hole as per your taps diameter.

The hole should be about 2 inches above the base of the container.

Use an appropriate coupling to fasten the tap.

Wait for the glue to dry. Check for leaks  by pouring  8 inches of water. 

Clean the container for dust, dry it and  paint it. I used a spray can of matte black.

An old U bend was used to prevent liquid from  entering  directly into the tap  after filtration through the gravel.

The U is positioned  and not fixed. It can be removed for future cleaning if the need arises.

Cleaned and washed gravel is added to  a height of 3.5 inches. This acts as a filter medium and also aids undisturbed bacterial growth. 

Construct a stand to your required height or  get a ready-made one. 

Here is the construction plan with dimensions.

Hope you find this useful. Feel free to share it with your friends for free non commercial use. I hold the rights to the design so do not under any circumstance use it for commercial purposes.

Click the link for the test results in PART 2 : Click Here

Regards,

Joseph