Bioreactor Turns Trash To Cash

by Rodel G. Offemaria

A composting bed using agricultural waste and African Night Crawler Worm, a project of the Numancia Vermi Multi-purpose Cooperative.

One’s trash could be somebody else’s treasure. This is a cliché that never gets tired especially in a society where economic classes are sharply defined between the affluent and the deprived.

But more than the philosophical allusion, waste disposal is a staple topic among environmentalists, urban planners, and other concerned citizens. It even gets shrill attention especially during the rainy season when canals and rivers are clogged by jumbled trash.

Individual efforts to clean up immediate environs can hardly hold back the rising tide of trash. In parts of the country, mounds of trash are more than an eye sore. These could trigger respiratory trouble and soured air, among others in a long list of irritants.

But there are sparks of hope in what appears to be a hazy waste management landscape. And these could be happening almost always quietly and away from national spotlight.

In Pagadian City, garbage collection units literally do the dirty work. The city’s Public Service Division’s General Services Office takes charge of garbage collection since 1991. It is manned by 64 personnel, 44 of whom, collect solid wastes in 21 barangays (villages) using 12 regular collection vehicles.

But the city, like its progressive counter-parts, has set its sight on innovative solution to the recurring waste issue. Guided by the landmark Solid Waste Management Act or RA 9003 passed in 2003, the local government leadership decided to adopt a technology-based option. The law empowered LGUs and also provides that "each LGU plan shall include an implementation schedule which shows that within five (5) years after the effectivity of this Act; the LGU shall divert at least 25 percent of all solid waste from waste disposal facilities through re-use, recycling, and composting activities and other resource recovery activities". It also decreed "that the waste diversion goals shall be increased every three (3) years", and encourages LGUs to implement re-use, recycle, and composting activities "designed to exceed the goal".

RA 9003’s stringent terms are substantially answered by a bioreactor developed at the Depart-ment of Science and Technology’s Industrial Technology Development Institute called "Bioreactor 500" (500-kilo daily capacity). This Accelerated Composting Technology has three components such as harnessing of composting process, appli-cation of solid inoculants, and use of bioreactor.

The inoculants are microbes present in the environment selected and isolated due to its ability to withstand heat of up to 60o Celsius, a very important characteristic since garbage generates so much heat that microbial inoculants must survive to do its decomposition job.

The microbes hasten the decomposition of degradable municipal solid wastes in 12 to 18 hours if incubated at 55 – 60o Celsius using a bioreactor. Biodegradable wastes like spoiled or wilted vegetables, fruit peels, meat/fruit/vegetable trimmings, food leftovers, fish entrails/trimmings, leaves/twigs, seeds, among others are converted into organic fertilizer. The inoculants have long shelf-life and can be sourced locally.

The Bioreactor 500 has a horizontal electric-driven stirred tank reactor, with aerated system, approximately 75-100 kg/d/cu.m. throughput, uses no external heat source, capable of batch or semi-continuous operation, uses forced air circulation, manual or automatic process control, and modular type. It is suitable to small-scale applications and fits the resources and needs of LGUs.

The Bioreactor 500 averts leachate (the smelly liquid from garbage) resulting to minor odor emission and competitive compost production cost.

Moreover, the organic fertilizer it produces contains nitrogen (2.09-6.0%), phosphorous (0.57-0.79%), potassium (0.14 – 0.17%), organic carbon (36-39%), moisture (22-30%), and is pathogen-free.

Pagadian City acquired the Bioreactor 500 through DOST’s Grants-In-Aid program and has been fully operational since May 2003. It handles biodegradable materials from the Agora market, slaughterhouses, and part of collected household wastes in the city.

In 2004, Pagadian City generated an estimated 52 tons of solid waste daily, 38 tons of the wastes went to dumpsites. The wastes include biodegradable materials (81.92%), residual wastes (16.69%), recyclables (1.34%), and special wastes (0.01%).

In the same year, the city produced about 68 tons of compost sold at P3 per kilo to local farmers and other consumers. Only 9 percent of total reco-verable materials per day were recovered, while the rest of the biodegradable wastes were cast off to the city’s 2.13 hectare open dumpsite.

The city wanted to meet the requirements under RA 9003, and sought DOST’s help to acquire an additional bioreactor with a bigger 1-ton daily capacity. This would ensure the city’s compliance to recover at least the minimum 25 percent solid waste diversion percentage required by the law.

In September 2005, the new 1-ton bioreactor went to work raising production output to 8,960 kilos of compost valued at P26,880. The two bioreactors absorbed 169,050 kilos of biodegradable solid wastes on 8-hour, 7-day operation.

Other than the cheery environment impact, the twin bioreactors put the city in a strong position to haul up a budding industry like horticulture, one of DOST’s development priorities through the flagship Small Enterprise Technology Upgrading Program or SETUP. The compost is earth-friendly and inexpensive, ideal for SMEs and acceptable to most international markets that are sensitive to environment and quarantine issues.

Domestic and inter-national demands are strong and growing for ornamental horticulture products such as cut flowers, fresh or dried foliage, live plants, and other dried ornamentals. In the domestic market, "roughly 80 percent of the total value of ornamental products" traded are foliage, DOSt’s Philippine Council for Agriculture, Forestry and Natural Resources Research and Development reported in 2007.

Prized ornamental plants that can be developed commercially include "orchids, bro-meliads, Mussaenda, Medinilla, Aglaonema, Heliconia, palms, and gingers", PCARRD noted. The most common cut flowers produced in the country are Dendrathema (chrysanthemum), orchids, Anthurium, roses, gladioli, Heliconia, daisies, asters, Limonium, and Gypsophila.

The world’s largest suppliers of Draceena by 2007 are Costa Rica, Guatemala, and the Philippines. But in Southeast Asia, Taiwan and Thailand are the regional export leaders, though compared to global leaders, their output are not substantial, PCARRD said.

The Netherlands topped the world’s cut flower exporters in 1999, followed by Colombia, Ecuador, Kenya, Israel, Spain, Italy, Zimbabwe, Belgium, and the US. This top 10 list may have changed little since. World horticulture exports at the time were valued at US$7.8 billion, and world imports were placed at US$7.5 billion, PCARRD reported citing data from the Department of Trade and Industry.

According to PCARRD, Dutch horticulture products that also grow in the Philippines include Anthurium, bougainvilla, Dendrathema, Cymbidium, Gerbera, Guzmania, Hibiscus rosa-sinensis, and pointsettias.

Growth prospects remain sunny. Domestic horticulture has a vast forest of opportunity.
Meanwhile, Pagadian City eventually imple-mented two-8-hour shifts to double the production to deal with the large volume of wastes collected and the need to increase compost production capacity. As of June 2006, three regular employees were hired and average monthly production volume went up to 3,000 kgs. of organic fertilizer out of 56,602 kgs. of biodegradable wastes.

The ITDI bioreactors allowed the LGU of Pagadian City to con-tinuously produce organic fertilizer widely used in its vegetable garden project, mitigated air pollution, generated employment, and provided additional income for the city. /MP