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Small Islands and ZERI: A unique case for the Application of ZERI

George Chan
United Nations University

Paper presented at an International Symposium on "Small Islands and Sustainable Development" organized by the United Nations University and the National Land Agency of Japan.

The first complete input-out table covering a whole economic system ever made was compiled for the Swedish island of Godtland, the traditional Hanseatic city state around Visby that was once one of the leading trading partners of the world. The outlook for Godtland and the rest of the Baltic is not so encouraging. The latest closure of the sugar processing plant makes an additional one thousand persons redundant. The future of the island economy in a Baltic Sea where all the economies around the rim are faced with rampant inflation and high unemployment demonstrates that the critical choices islands are facing in the Caribbean, the Pacific or even in Norther Europe are not so distinct indeed.

Island economies, and for all the crisis that they are facing in the wake of global warming, rising pollution, over-fishing, unsustainable tourism, and export driven economies demands a most creative approach. The advantage is through, that as island economies can easily undertake input-output studies, these nations can also undertake the most advanced output-input studies, which are at the core of the methodology for the zero emissions research initiative that the UNU has launched in 1994. After all, islands have all the problems to face the economists and environmentalists can enumerate. Though these states have the advantage that their inherent economies of scale permits them to address the issues at stake in an integrated way, likely to offer models for sustainable development for the rest of the world to learn from.

Indeed, sustainable development requires an integrated approach, a complex systems modelling. And when industry and urban development needed to mimic nature's concept of "all waste equals food," it is easier -though still difficult - to achieve on an island than for a land-locked national. A detailed review of the output of al activities on an island will quickly identify input- imports which are non sustainable, that could be substituted by highly sustainable and low toxic products. The case of beer, cleansing agents and construction materials are cases which demonstrate that the opportunities for local development are legio, but that the vision and the determination seems lacking. It is against this background that the ZERI programme is motivated to provide all the support needed to secure a successful study of the island economies with sustainability as the driving concept behind the development process.

Pilot Project in Fiji

After one year of consultations and feasibility studies by the United Nations University, coordinated by Mr. Gunter Pauli, Founder of Zero Emission Research Initiative (ZERI), an International Expert Meeting on Brewing-Aqua-Agriculture (ZERI-BAG) was held in Beijing on 1-4 April 1995, followed by a ZERI World Congress in Tokyo on 5-7 April 1995, and a one-day workshop with Mr. Pauli and the ZERI panel of experts: Prof. Li Wenhua from China, Prof. Keto Mshigeni from Tanzania, Dr. Mauricio Carcia-Franco from Venezuela, Mr. Eng-Leong Foo from Sweden and Prof. George Chan from Mauritius. The latter, who is the author of the ensuing report, was given the responsibility to design and implement a pilot project to make maximum use of the residues of an existing brewery in Fiji.

The author already has a long and fruitful association with Fiji where he built his first Integrated Farming System 26 years ago. It consisted of a piggery with digester, algae basin, fish pond with ducks, and vegetable garden in Sawani village, 16 km out of Suva, Capital of Fiji. It provided biogas for cooking and lighting, feed for the fish and ducks, and fertilizer for various crops. Some crop residues were used as pig feed, which was supplemented with wheat bran, wheat pollard and fish meal from local industries. Since then, the author has advocated integrated farming systems in 71 countries and territories, and has demonstrated that individual family integrated farms are viable entities where water is always available, which is always the case in the wet tropics.

The best locations are low-lying lands and marshes, which are marginal and not presently utilized because of easy flooding, and where the soil is suitable for brickmaking it can be sold to finance the integrated farm, which is the success story of Vietnam where the author is involved in a people-oriented eco-farm project.

The objectives have been to provide the individual farm family with affordable means of production for economic and ecological rural development in a self-reliant system without costly inputs or environmental degradation by integrating various agro-industrial activities. They include different livestock using local feeds to produce the daily wastes as raw materials to operate an appropriate digester for primary anaerobic treatment with production of biogas fuel; shallow basins for secondary aerobic treatment with growth of natural algae to produce the required oxygen and the algae used as feed; deep ponds for tertiary treatment & polyculture of fish and macrophytes as food and feed; pond water demineralization with fertilization and irrigation ("fertigation") of various crops using multicropping, aquaponics and aeroponics; and natural processing of crops enhanced with biogas-operated equipment or processes and using the crop and processing residues as livestock feed. So far, in Vietnam, the income of individual families involved with the integrated farms designed by the author are earning up to 20 times the income they used to get with rice monoculture, while doing less routine work. With additional innovations and higher-value crops, the income can be considerably improved. Such highly-rewarding rural development is unique, and unmatched anywhere in the world.

Integrating such a farming system with a brewery to treat and utilize the brewery wastes can be a viable proposition not only for the beer manufacturers themselves, but also for adjacent farmers receiving the brewery wastes and willing to use the integrated farming systems to solve the brewery waste pollution problems while recovering the resources as means of production such as fuel, feed and fertilizer, for their own farm activities.


Beer manufacture and consumption are increasing worldwide, in particular the developing nations, and produce huge amounts of wastes which are too costly to treat or dispose of, and are consequently left to degrade the environment. The objectives are to have brewers and farmers collaborate for mutual benefits by utilizing all the wastes as useful resources, after full treatment using natural processes and at very low costs, and make beer brewing as well as other similar industrial processes more economic without any environmental pollution or depletion of natural resources.


The one-hectare pilot plant will be built as near as possible to an existing brewery, provided that the subsoil retains water. It will use some of the different wastes produced to demonstrate the validity and capacity of 5 main processes as shown in Figures 1 and 2.

The wastes are as follows:

(i) Solid Wastes

The solid wastes are the residues from grains and additives used in beer making, and have a high protein and fibre content, They are too indigestible as an effective feed for livestock because of the ligno- cellulose, so it is broken down naturally by growing straw mushroom (Volvariella volvacea) on it with simple means -- a common occupation of farmers in China and Vietnam. It is proposed to try the shitake mushroom (Lentinus edodes), which is the most expensive in the world, using a technique developed in Fijian, China, using brewery wastes and straw instead of cutting down oak trees. Another way of using the solid wastes more economically is to grow selected earthworms of high protein content as chicken feeds, instead of feeding them with grains. The residues can be used as good compost, or used in feed formulation. The livestock produce wastes which are given primary treatment in a digester while producing biogas as fuel for the brewery. There are many digester designs to choose from, and they vary from the brick and concrete one for small digesters which was designed by the author and built at various places in Fiji for more than 20 years, and reinforced concrete or steel ones for big ones, using plug-flow or up-flow, which must be specially designed to suit individual cases. For the pilot project, the brick and concrete digester will be used but with an arched roof instead of the conventional reinforced concrete roof, as shown in Figure 3.

The effluent is used to grow algae in shallow basins by photosynthesis while producing oxygen during the day to give secondary treatment to the remaining wastes by oxidation. At least two basins should be provided, used on alternate days to allow algae to grow undisturbed for one day for optimum yield. The algae are also flushed every two days into deep ponds as fish feed. Most algae basins fail when the accumulated dead algae consume more oxygen than what is produced by the live ones. It is also better to make use of a natural resource to feed fish rather than letting it rot in the basins.

The highly-mineralized effluent flowing into the deep ponds also encourages prolific growth of various plankton as fish feeds. So fish polyculture, which has been widely practiced in China for centuries, can produce 10 to 15 tons of fish per hectare per year without having to add artificial feed except for grass grown on the edges of ponds to feed the grass carp. Five or more other kinds of fish are used to feed on the different plankton produced daily, which is important because any feed, natural or artificial, that is not consumed is a potential pollutant.

The fish in turn produce their own wastes which are treated naturally by the self-purification capacity of the pond water, and the mineralized effluent is then used to irrigate and fertilize all kinds of crops in aquaponic floats made of bamboo or organically produced plastic panels on half the pond surface, on in aeroponic towers and greenhouses on land -- all current practices in China.

(ii) Liquid Wastes

Too much water is used in beer making for cleaning purposes - between 20-30 tons to make one ton of beer in developing countries, and at least 7 tons in the developed ones, which makes treatment of liquid wastes very expensive, and even prohibitive in the poorer nations. So the first logical step is to reduce this wastage of water, first by better housekeeping and then by using organic cleaners instead of caustic soda and other toxic materials. The BOD varies between 1,000 and 1,500 mg/l, and the COD is 508 more. Such a huge quantity of water should be recycled, but not in digesters because of the prohibitive costs involved, but in a minimum of two long and narrow primary ponds of 1 metre deep for at least two days' retention.

As for the algae basins in (i) above, the design of the ponds should also provide for their individual flushing into the deep fish ponds by gravity, as clearly shown in Figure 2, in order to avoid the problem of dead algae accumulation. It must be added that cleaning the primary ponds is not as easy as cleaning the algae basins, and can put the plant out of action for many days, so the need to flush the primary ponds every two days becomes much more important. The discharge of so much dead organic matter into fish ponds or rivers can also create some major pollution problems as well, because of depletion of the dissolved oxygen.

(iii) Waste Heat

The waste heat from the brewing process should be recovered and used to heat water for washing the equipment or other uses. The biogas generated from the livestock wastes is a convenient source of fuel for the same purpose in the pilot project. For a full-size treatment plant for the whole brewery, electricity can be generated from the biogas to supply most of the brewery needs.

Recovery of the waste heat is not urgent in the pilot plant, so this work is better left to the other bigger pilot projects of ZERI.

(iv) Carbon Dioxide

Much carbon dioxide gas is emitted during the brewing process and can be recovered for use in the brewery itself or bottled under pressure and used for draught beer. Unfortunately, the equipment is still relatively expensive for the small breweries, and it is hoped that less expensive equipment will be available for trial in this pilot plant. Other possibilities such as the use the carbon dioxide in greenhouses, or its conversion into sodium bicarbonate for higher production of high-protein spirulina, will be tried instead.

(v) Spent Yeast

The technologies are already available for recovery and reuse of yeast, and for manufacture of some pharmaceuticals, with the residues mineralized in bio-oxidation ponds before using them to fertilize fish ponds. This pilot project will not be involved in such work, as it will be dealt with on a bigger scale in other ZERI plants.


With the exception of waste heat, bottled CO2 and spent yeast, which the brewery itself should do because of economy of scale, the main objectives of this pilot plant are to recycle all the other wastes or residues on small individual farms around the brewery, effectively and efficiently, especially under the favourable tropical climatic conditions, and utilize all the byproducts as completely as possible without costly inputs or environmental degradation. It is true that the main purpose of a brewery is to make beer for profit, so the recycling processes must show a profit too or the brewers will have no incentive to include them in their brewery operations. On the other hand, the individual farmer must also have immediate and tangible benefits for accepting to recycle the solid and liquid wastes of the brewery. The proposed pilot project is to convince them that the wastes or residues are resources which can be used, with or without microbial and other inexpensive processing, as fuel, fertilizer, feed or raw materials for the brewery or for the adjacent farms willing to collaborate in such work. The results will be available for the second ZERI World Congress which will be held in Chattanooga, USA, in 1996.

Immediate action

It is fortunate that much field work regarding such a project has already been done by the author in many countries, and the experience can be put to good use on a small scale for more study or investigation at a worldwide level before designing the full scale plant. Much time and money will be saved because top priority has been given to this pilot plant by UNU-ZERI.


The best way for UNU-ZERI to proceed is to involve the various Fijian government departments concerned in the implementation of this project, as they are more familiar with the local conditions. Three of them are identified below as the principal ones, with others called upon to help as and when required, and they should contribute their available expertise and the use of any equipment, machinery and any other tools they already possess, and UNU-ZERI will pay for the required labour, fuel and other materials. Fiji should also provide all the necessary local transport for the project.

  1. The most suitable site should be near the brewery, with the subsoil clayey enough to hold water without importing clay from elsewhere. A low-lying or even marshy land is the best site, unless it is too acidic. The Department of Lands and Surveys can help to locate a suitable site of 1-2 hectares of marginal land for the pilot plant, with possibility for expansion to meet the needs of the brewery. The Government of Fiji, or the brewery itself, should contribute the land for the pilot project. The required amount of solid and liquid wastes should also be supplied free of charge by the brewery to the project, as requested by UNU-ZERI.
  2. The major works consist of digging the two deep ponds and the construction of the digester. The Department of Public Works can help with bulldozers and excavators to remove one metre of soil in each pond and build up the dykes on the sides to a height of 3.5 metres. The ponds will be filled with water to a depth of 3 metres. The construction of the digester will require bricklaying for the walls and some formwork for reinforced concrete for the floor and half the arched roof slabs. The minor works involve the algae basins and bio-oxidation ponds. UNU-ZERI will pay for the labour, fuel and other materials needed.
  3. The livestock, fish, crops and other farming activities are the concern of the Department of Agriculture, Stock and Fisheries which will make use of the nutrients produced in the treatment processes, operate all farming activities, and collect all relevant growth data. It also provides all the required livestock, fish, plants and seeds for the project, together with their supplemental feeds, and have them back free of charge when they are ready for market. To save both time and money, some specialized crops and growing techniques such as aquaponics and aeroponics may have to be introduced to local staff by appropriate experts from overseas, and paid for by UNU-ZERI.


The construction period will take two months, and the facility will start functioning a month later. The author will be available to build the project in late 1995. During that period, he can conduct courses for staff of various departments to operate the facility. At the end of August, an expert meeting of ZERI-BAG can he held in Fiji to evaluate the pilot project. By the end of 1995, the Department of Agriculture can take over and work with the staff of the brewery to train them for eventual transfer of the facility to them. In February 1996, another expert meeting can be held in Fiji for evaluation and report to the Second ZERI World Congress in the United States of America.


Obviously, this proposal is not appropriate for breweries which are located in urbanized areas or where land price is prohibitive. It is most suitable in suburban areas and in the developing world where new breweries are more likely to be built in the future. There should be a mandatory requirement that any new brewery should be located where it can be surrounded by individual integrated farms, where all concerned could benefit tremendously from Zero Emission, as shown in Figure 4. Otherwise, no brewery or any other industrial activity which pollutes the environment should be approved by the local authorities.

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