POLLUTION REDUCTION WITH ALGAE
by Masse Bloomfield
I have been interested for some time in developing a system to clean up sewage and produce food in the process. This interest began when I wrote a book” The Automated Society.” I am sure that a closed recycling system is going to be needed for long voyage space flights as well as for my future automated cities. I had thought about the use of algae as the first step in a way to recycle sewage. The system as I conceive it is low tech.
The system is based on the fact that some microorganism or microorganisms will remove almost all the pollutants from a sewage stream. Wetlands can be used to recycle the effluent. I didn’t think wetlands was the answer because it is so slow and takes up too much space. If I remember correctly, the Chinese use “night soil” to feed their carp in fish ponds. Somehow the use of “night soil” in a fish pond sounds unhealthy.
There is a system in use currently which removes pollutants and recycles water for a fish pond. The system is called the Aquatic Bioenhancement Systems (ABS) treatment system. Because the ABS system removes the pollutants from fish pond water, I was under the impression that the algae could remove almost all the pollutants in a sewage stream. I have been told that a sewage system would have to have full scale secondary treatment. However, the ABS system polishes up the pollution from a fish pond and use the algae as fish food. I think this system should be able to clean up most organic pollutants in any body of water. Perhaps the answer to the sewage stream, is agitate the stream in order to break up the solids into microscopic particles and then filter out the larger particles, to make sure there are no particles the algae wouldn’t be able to ingest.
The ABS operation is set up to clean polluted water and then use the algae as fish food at a fish farm, recycling the water. The algae grow on screens as effluent flows through a series of trays. Two items have been written about the ABS system by Walter H. Adey at the National Museum of Natural History in Washington, D.C. His paper “Phosphorus Removal from Natural Waters Using Controlled Algal Production” appeared in Restoration Ecology, March 1993, p. 29-39, and a chapter in his book “Dynamic Aquaria.” I have written a paper “The Food Factory” which I put into the literature through the National Technical Information Center. That paper is available on request. The food factory is what I thought I needed to make the automated city a closed system. The basic part of the factory was turning sewage and garbage into microorganisms that could then be used as food for animals or as fertilizer for plants. I did not consider the algae as food for humans, but it could be processed with either ultraviolet light or nuclear radiation to kill any organisms and make the algae fit for human consumption.
Because the system is low tech using pumps, trays, scrapers and organisms, I believe it could work anywhere. The system could be used to clean up sewage, organic garbage, recycle water and at least produce food for a fish pond. The pond in turn would produce food for humans.
There was a Biosphere experiment that was going to answer the question of how to recycle waste for long term human space voyages. That project is still going on, but they didn’t find the answer. There have been other experiments. I collected a bunch of papers on the subject and was not able to find that kind of answer needed for my automated city which needs to recycle the sewage of 10,000 people.
You may want to call the fish farm whose telephone number is (830) 254-3319. The ABS system is now being marketed by Hyrodmentia, 3303 SW 33rd Road, Ocala, FL 33474 or P.O. Box 367, Ocala, FL 34478.(Tel. No. (352) 237-6145). I’m not sure how much research they are doing or what Dr. Adey is doing. Also if you go to Google and put in the search statements ["walter mulbry" + algal turf] or ["algal turf scrubber" + adey], you will learn what is happening recently. Walter Mulbry is running an experiment taking liquid sewage from a pig farm and running it through the algal trays. His preliminary results show that the system cleans up the pig sewage very well.
You might want to talk to Dr. Adey to find out where his research is and what he thinks about recycling sewage and organic garbage. Also I think that a pilot plant to test whether this approach is of any value, is worth the effort. It shouldn’t take very much money to start up a research project to determine the worth in a small scale effort to determine if the system can in fact eliminate sewage or organic garbage and produce clean water and food, even if the food is for animals.