Did you know that half of the waste produced in Chilean households is organic waste, like fruit and vegetables remains and other items such as pieces of wood?

January 27, 2017

If we consider that the total amount of household waste in our country is about 7 million tons per year, according to figures from the Department of the Environment, then the organic matter is around 3.5 million tons, which are accumulated mainly in landfills or, in the worst cases, thrown in public spaces that end up becoming illegal waste dumps.

The problem is that such material is far from trash - that is to say, unusable waste -, but, on the contrary, it still has many possibilities to extend their useful life.

While the most well-known form of reusing this type of waste is to take advantage of the methane gas that is generated as a result of decomposition, there are many other useful ways to use them.


Maulean researchers have spurred a number of initiatives aimed at using this type of resources, several of which are related to the waste generated by the agro-industry that generates more than 1.5 million tons per year, of which 45% is "contributed" by the Maule Region.

A material that, according to Professor Diogenes Hernández, from the Institute of Chemistry of the University of Talca, "is discarded without an analysis of the caloric or nutritional properties that may possess".


An example of this is the study carried out about "tomasa" – as the residues of processing tomato is called -, which, according to what researchers discovered at the Department of Health Sciences of the UTALCA, could help to combat one of the leading causes of death in the region and in the country: cardiovascular diseases.

And because this plant - of which close to 18 thousand tons are produced every year - has a antithrombotic function, which could help to reduce the risk factors for this type of ailments, adding value to this residue that today is given away or sold at a low price for animal feed.

"The tomasa used to be waste, but the discovery these properties transformed it into a waste product that has a huge potential impact on the environment. It could transform the tomato industry in an industry with reused waste," explained Ricardo Diaz, Director of the Center for the Study of Processed Foods, of the Utalca.

In 2017, researchers participating in the project will carry out clinical trials in order to verify the positive effect it has on human health. "If the results of the study confirm this, it would be so important as to make it even mandatory to introduce it in the flour in the whole the country," Diaz said.


Another alternative to the use of waste was the initiative led by Professor Diogenes Hernández, from the Institute of Chemistry of the UTALCA, who, along with academics from the Department of Engineering of that same Academic Institution, developed a food supplement that benefits sheep and goat producers in the Maule Region.

The project, supported by the Maule Regional Government through the Innovation Funds for Competitiveness, FIC-R, permitted the opportunity to analyze the qualities of a number of residues and to generate a low-cost food, which improves the diet of sheep and goats, particularly in times of grass shortage.

In the formula were used residues from olive oil processing (alperujo), from the processing of apples (pomasa), corn waste and wheat milling residues, among others, that are mixed in specific amounts and are administered to ruminants as a complement to the prairies grass.

The food was tested in about 50 lambs and goats for four months, in two experimental farms.
"The formula fulfilled its feeding function, allowed the meadows to be kept in good condition and that the sheep and goats mothers had more time to recover before the next mating and calving, which in turn involves new generations with good weight and quality," said Hernández.

The supplement is of better quality and lower processing cost than bales of grass, which goes in direct benefit to the economy of livestock producers.

 "It covers a crucial issue in animal production, since food is between 60 to 70% of the production cost of the business, then whenever possible to reduce it, it means a great benefit", noted the professional from the local development program (PRODESAL) of the Government Department of Agriculture in  Rauco County, Carlos Krauss.

At the end of the project it is expected the development of a viable technical and economic methodology for livestock producers in the area, as well as to create a successful mechanism to transfer the generated knowledge.


The generation of energy is another area in which waste can be a contribution, as academics from the Department of Engineering of the University of Talca are trying to demonstrate, by developing various initiatives aimed at promoting the use of state-of-the-art technologies.

"It consists in the installation of a small power plant -at the Curicó Campus of the UTALCA- that, fueled by the combustion of various organic, agricultural, forestry, plastics and paper waste, generate electricity and/or heat in a range from 10 to 25 kilowatts", explained the director of the project, Johan Guzmán.

The professional said that while in many countries the use of this type of system is common, in Chile is still unknown, so it is expected that this experience will serve to make them known and open the discussion on the subject.

"The technologies to recover waste are old, and are used intensively throughout northern Europe and in Japan. The business models - without subsidy - include large plants that integrate automatic classification of trash, recycling on an industrial scale and generating energy from waste or small communal plants with energy and material recovery for local communities," he said.

The researcher noted that in addition to the benefits described above, there are other equally significant ones: the reduction of up to 15% of the trash that goes to landfills, which together with mitigating the environmental damage it also represents economic benefits for the people.

"The trash deposits have a cost in transport and in the effects of pollution in large areas of land, with the dangers that they carry, like fires in landfills," said professor Guzmán.


Heating is another of the areas where agricultural residues could be a solution. For this purpose, and in the same way in which the industry currently develops pellet from wood waste, researcher Ricardo Baettig -from the Department of Forestry Sciences of the University of Talca- is developing a project called "Innovation in Densified Solid Biofuels of Agricultural Origin for Urban and Industrial Residential Consumers", which is being financed by the Innovation Fund for Competitiveness (FIC-R).

"The initiative is clearly aligned with the promotion of the use of alternative fuels, such as biomass, and we shall attempt to demonstrate the feasibility, from a technical, environmental and economic point of view, of manufacturing, in medium and low scale, solid fuels derived from agricultural residues, as is currently done with wood waste on a large scale," he explained.

He stated that the benefit is clear: "to demonstrate that it is feasible to produce briquettes and pellets in small and medium-scale, in order to have homogeneous, low humidity fuels, but that does not lead to an increase in the current cost of home heating, achieving prices that are competitive with those of wood."

At present, the production of pellets and briquettes is based exclusively on the use of residues from sawmills and wood workshops with large levels of investment, as opposed to this proposal, which is based on the use of crop residues from maize, wheat or rice, in addition to agro-industrial waste, such as skins and pits and even recycled paper, peri-urban weeds, pruning remains and other components, which implies a diversification of the sources of raw material.

The scholar explained that the biomass pellets are a viable and sustainable alternative to renew heating methods, through the use of local fuels, not imported, renewable and whose emission of particulate material are compatible with its use in the cities of the south of Chile, which currently have high rates of contamination in winter due to wood heating.

During the project a business model will be developed for pellet production based on small and medium scales of production. According to preliminary estimates, a small farmer can generate about 200 kilos of densified fuel a day, either pellet or briquette, with a total investment of less than eight million pesos (US$ 12 000, approx).

"Considering a sale price of 100 pesos per kilo, he could produce some 40 tons a year that would return approximately four million pesos (US$ 6 000, approx), for which processing the waste from about 10 to 20 hectares would be sufficient," stressed Baettig.


 Meanwhile, in order to contribute to the protection of soils, the Soils and Crops Technological Center of the UTALCA is developing a liquid biofertilizer from agriculture and agro-industry residues and livestock manure, which ensures the sustainability and care of the soil.

The director of the center, Hernán Paillan, explained that his goal is to "prevent it from losing its natural characteristics and getting impoverished. As long as it stays healthy, it will produce healthy food".

One of the components, livestock manure, possesses one of the fundamental characteristics coming from its treatment, which includes composting, to become compost, which involves fixing carbon and reducing emissions of pollutants to the atmosphere.

The biofertilizer supplements the normal handling of organic fertilization of a crop. "It is applied to plants through irrigation in liquid form, feeding the present bacterial flora in the soil and contributing to these compounds to generate nutrients," added Paillan.

The proposed idea seeks to achieve a first prototype and to assess organic crops, and along with this, to transfer knowledge to farmers and public bodies through workshops.