Adler, Paul [PAdler@afrs.ars.usda.gov] wrote

>Jacky wrote:
>>In Japan activated carbon (from oil palm nut shell, rice, wood
>>chips, coconut) is often used in water treatment too for horizontal
>>systems with plants. The pores in the oil palm nut shells are
>>especially good as they provide the space for attachment of
>>the microflora as well as for the absorption and concentration
>>of nutrients.
>
>Q1: What do you mean by "activated carbon" and do you have any
>publications describing this work?

I collected a lot of literature and samples of materials when I was in
Japan for the UNU/IAS IBS demo project in Fiji (Montfort Boys Twon), met 2
companies that make this materials, but left all the materials there when I
returned to Sweden. So I am sorry I cannot quote references for you and
give you contact names in Japan.

I believe the process in making these carbon is similar to charcoal making
- in oxygen-limited kilns.

I investigated on the use of activated carbon for the UNU/IBS demo project
in Fiji. The project's first and original workplan (April 1995) was
designed to use brewery solid wastes and waste water. This was never
executed unfortunately as the site that Gunter Pauli (ZERI project leader)
chose was too far from the brewery and then George Chan (site manager)
could not get his pigs to eat brewery spent grains. So the project became
an integrated farming system (pig-algae-fish-vegetables) using commercial
feed and kitchen leftovers which is replicated from those used elsewhere as
in Vietnam, or China. For research, I later was interested in the use of
activated carbon in a "reactor" before the slurry goes to the algal basins.
The idea is to absorb whatever (?) that it can and then I wanted to use
this material to grow high-priced vegetables in hydroponic plant cultures.
The hypothesis is that nutrients and growth-promotors that are
absorb/concentrated in the carbon and making it possible to support better
plant growth without the use of commercial fertilisers or nutrients. That's
why your paper discussion and Rakocy's work are of special interests to me.

I now found out that the dried material from the bulbs of water hyacinths
have a very high water holding capacity. I should be able to concentrate
nutrients digested liquid portion in this material (NH3 will be lost
unfortunately). This material can then be used in many ways - plant
substrate, mushroom cultivation, etc. I wish to develop a project proposal
together and to interest a research group or a participant from this
audience to test this idea. This idea is also deeply rooted in efforts to
make water hyacinths a resouce. It is a water weed in many countries as you
know. The Samoa project (2000-2002) that I will start in May will use water
hyacinths which is also a by-product of the IBS.

"Activated carbon" is extensively used in e.g. golf courses. Here they want
green grass on dry land. What they do is to layer sand for easily drainage
of rainwater and then put a layer of "activated carbon" and then some soil.
The carbon absorb water and fertiliser and keep grass healthy and green.
Activated carbon is also used in Japanese traditional homes which are made
of wood. In the space between the ground (cemented), and the ground floor,
they put this carbon to absorb "toxic gases" as well as to maintain
moisture level.

regards
jacky
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