BioAbono: A Sustainable Future
GENERAL BRIEFING ON MUNICIPAL SOLID WASTE MANAGEMENT (MSWM)
This briefing contains the scientific and technical concept about the history of the municipal solid waste (MSW) disposal solutions given from the last quarter of the XIX century to our present days.
I. DUMPING SITES
This is the commonest way of disposal of MSW in cities and municipalities in the third world; generally, they are found on the outskirts of the urban areas, turning into sources of contamination due to the incubation and proliferation of flies, mosquitoes and rodents; that in turn are disease transmitters that affect the child population's health which has its organic defenses in a formative and creative state; therefore said situation produces gastrointestinal, dermatologicals, respiratory, genetic, and several other kind of infectious diseases. Consequently, dumping sites have a very high economic and social cost in the public health services, and have not yet been estimated by these governments, industries, and families.
II. RIVER DUMPING
River dumping is another common way of disposal of MSW in the third world. MSW is dumped in rivers that later feed the water treatment facilities of downstream municipalities and cities.
It represents a very high ecological, socio-cultural, tourist and economic cost, due to the contamination and reduction of protein sources provided by the rivers (fish), forests (in its natural state) and balanced habitats. Not to mention the loss of panorama (vegetation) by the swellings that restrain the agricultural development in the suitable areas; it ill implies a general deterioration of man's habitat which is hard to measure in the immediate future.
III. LANDFILL TECHNOLOGY
Developed and applied in England during the last quarter of the XIX century. It was later applied in the United States of America and the rest of the world.
The technology basically consists on, based on some knowledge (underground water sources, distances to human settlements, etc.), using a plot of clayey land that has to fulfill certain requirements ( GWT (ground water table), soil permeability) to stare the MSW, Once the aforementioned information and requirements were had, the bottom or bed of the landfill which was originally waterproofed, is replaced by a drainage system able to collect a higher amount of leachates (contaminated effluents produced by the decomposing of organic matter that have over 40,000 to 50,000 mg/lt of BOD (Biological oxygen demand)); atop this waterproofed bed's drainage system, layers of municipal solid waste (as is the case in Colombia: nuclear, photographic equipment, hospital, industrial and residential waste) is placed one meter high, interleaved with a 25 cm. layer of sell substance (having then these layers a airing system) to be able to produced aerobic reactions inside this biodegrading process.
The airing system used in the landfill (ducts made out of rocks or perforated pipes) did not provide enough air (oxygen) to the already active biodegrading process generating then Anaerobic reactions capable of producing methane gas (CH4), Carbon dioxide (C02), and sulfuric anhydrite (SH2) among others; this reaction occurs, logically, at different pH, ranging between pH3.2 to pH8.9. That wide of a variation of pH has highly toxic and adversely effects the environment.
Since the 1860's this technology has been a major scientific concern because of the atmospheric contamination caused by the C02 (Stockholm University, 1961 briefing of professor Berth Collin; "once and future landfills", National Geographic article, May 1991; FUNDACIENCIAS' article, December 1992)and more recently, the atmospheric contamination caused by methane gas (CH4) (see results of research done by the Lovaina's University Department of Biological Engineering's professor, J.E. Nyns). Well versed environmentalists and the scientific community have been extremely worried about these effects.
Leachates, defined as concentrated liquids produced during the biodegradation process (or better described as the waste fermenting process, have basically three origins:
The first one: Rain water, falling over wide areas of the landfill and working its way through layers of decomposing waste to the bottom. Percolating through the soil and reaching, at certain point, the underground water resources which will later be used in conventional water treatment facilities.
The second: Data Subject to Approval
The third one: The hydrolyzing process that occurs between the acid pH ranges, mixing the carbon hydrates and cellulose; then, causing an anaerobic fermenting reaction that produces alcohol and water.
Around the world, less than 25 % of the leachates have been collected in any of the evaluated landfills. Towards the 1950's, a general warning rang in the Los Angeles landfills (State of California, USA), forcing the search for alternatives to this technology. At which point incineration stations developed (see essay written by M. Ramirez, Universidad Tecnologica de los Llanos, over Doña Juana's landfill's contamination caused by leachates, and INDERENA's report on Puente Nacional's landfill). It's worth mentioning that this technology, being science dynamic, drags on; being now more than a century old.
IV. INCINERATION STATIONS
Incineration stations boomed and developed quickly in the 1970's, then 'Martin" from Germany was the largest producer of this type of industry.
The system incinerates 100 % of the waste that has 40 %, humidity. It is important to start the combustion with ACPM, generating the temperature that produces steam that moves a turbine that moves an electric generator and thus produces energy in a small scale.
The environmental issue raised by these type of plants was the high amounts of C02 and CO produced; Nevertheless, design engineer's concern was to hide the contamination produced, using filter to stop suspended solid particles produced by combustion exhausts; This type of filters won't break the covalent bonds of the molecular chains of C02 and that contamination is extremely hazardous to life.
For further information refer to studies conducted by the university of Lund-Sweden, regarding the environmental effects of the acid rain produced by the incinerator plant of Malmo (contact professor Per Johansson, head of research department).
Several other countries like Japan, U.S.A, France, Chile, Argentina, had installed this type of plant and then dismantled them later on in the 1980s. In Colombia, in 1994, incineration stations were installed in the municipalities of Fusa and Guatavita, Cundinamarca; there wasn't any recycling done of usable material and a highly contaminated environment developed during the short span of their operating life.
V. CONTAINERS
The containers technology was developed by Denmark and applied in Germany where education exist on Separation at the Source.
The containers are placed in an specially adapted plot of land; the MSW are discharged in the plot during a three day period approx., time enough to recycle the usable material and separate the non usable; afterwards, the biodegradable waste is placed inside the containers each of which have a 10 ton waste capacity (20 cubic meters).
Temperature and humidity is controlled in each computerized container which is thus completely sealed avoiding contaminating odors into the atmosphere. It is a highly expensive system and several of them are needed in the handling of the MSW generated by a single settlement, at an average cost of US$ 50,000 each, for a capacity of 10 to 12 tons of biodegradable waste converted to compost.
VI. MODERN CRITERIA
The aforementioned technologies are considered outdated by scientific and modern technology standards for the previously mentioned reasons. This is not to say that in the modem world there is no space for "waste"; recycling and reuse of materials is the new order ecologically and economically because of:
· Reusing cellulose fiber for the production of paper reduces deforesting; trees are second only to coral reefs, as a source of oxygen production on earth and one of the few systems capable of breaking the covalent bonds of C02. Additionally, it will save the energy needed to process its wood to create the cellulose fiber used for the production of paper and that represents process savings in the production of paper.
· Metal processing and the use of scrap metal implies lesser use of ore and coal mines that cause a grave environmental impact. In Colombia, 500,000 tons of ore is imported yearly by 5 steel mills (Pacific, Carib, Muña, Boyaca and Medellin steel mills) while thousands of tons are buried on the Dona Juana landfill.
· Plastics are divided in two major groups: high density and low density. Each one of them has specific molecular characteristics creating both contamination problems thanks to its long lasting life (the time it takes to degrade is estimated in approx., 2,000 years). Nowadays, we are facing the need for management of this material which is used in a large percentage of everyday products. It represents 5 % of the total recyclable material. Used in the manufacturing of stands and therby, replacing crops that were needed for that manufacturing process (e.g.: as an alternative to wood and reducing deforestation), plastic cans, plastic bags, hoses, seats, tables, tiles, etc. Plastics are proven to be recyclable up to 22 times.Recycled glass requires only 800º C to melt and reshape while first time glass requires 1200" C. It represents a 33 % economy in energy consumption. Blown glass handicrafts could be produced with local technologies where non existent sophisticated ones are available.
Today exists a recycling market for all these products (for example, in Colombia check with : Conalvidrios, Carton America, Carton Colombia, Medellin, Boyaca, Muña, Carib and Pacific steel mills, Duitama Hose manufactores, etc.), All this companies receive an average of 10 % of recyclable materials that all together represent only 15 to 30 % of the Municipal Solid Waste (MSW) generated.
The problem raised before by the lack of appropriate technology was: the recycling of domestic biodegradable waste that represents an average of 75% of the total waste produced in our areas. Surging as solutions, first in Europe and then in the USA, is composting process. Thanks to a group of Colombian scientist's efforts and their visions of a new world, we have, since 1991; a bio-organic fertilizer produced from the traditional biologically enhanced compost technology; that represents an integral solution:
FUNDACIENCIAS' scientists have enhanced the compost produced from organic biodegradable waste using microbiological and mycological stocks. This special stock was selected after a scientific study of bacteria and bacillus in which 1200 species of bacteria and 486 of fungi were isolated and analyzed. From that study only six (6) species of bacteria and four (4) type of fungi were found to be useful enough to inoculate them into the process; the rest of the microorganisms were either harmful or innocuous to the process. A group of microbiologists, mycologists, biologists, biophysicists, and engineers worked in the creation of this process. The study itself lasted 7 years and sampled 30 kg MSW(in the lab) to 70 tons MSW(in the field). The resulting end product was an excellent bio-organic fertilizer with a high content of NPK and other, lesser elements, needed for crop productions: BioAbono!
The main purpose of the FUNDACION COLOMBIANA DE ClENCIAS has been: to preserve and better the environment; start a biological agriculture culture worldwide; to use and value the MSW which has been wrongly named "waste"; and to confront and stop the destruction of prime material. Producing an ECOLOGICAL-ENVIRONMENTAL, SOCIAL, CULTURAL AND ECONOMICAL benefit above that that is found in traditional landfill burials, incineration stations, etc.
Luis Orlando Castro, Ph.D.
Carretera 7a.No.27-52 0f.703
Tels.2815435 -Fax.3342268
Santafé de Bogotá, Colombia