A A mixture of food scraps, debris generated by pruning trees and grass or even wood shavings can generate benefits for the environment, when treated properly. Aida Gamal Eldin Mahmoud, a graduate student at the Institute of Biology, in scientific initiation research guided by professor Mohamed Habib, produced a compound combining green and organic waste for use in plantations. Aida's intention is to apply the fertilizer to the University's trees and make it available to school gardens and farmers in the region. Composting has a good expectation of use, as in addition to resulting in economic gains, it allows institutions to provide a correct destination for this waste that would otherwise be discarded in landfills and other places.

Composed has residue food and tree pruning

Aida began working with the idea after a six-month exchange at the University of California, in 2004. Contact with various forms of composting led the student to develop a pilot project for application in universities, schools, clubs and condominiums. “When I returned I was surprised by the lack of work in this area, considering it is such a beneficial process for the environment. I learned about some domestic initiatives and also the project at the Federal University of Santa Catarina, which I took as a basis”, she explains.

Aida visited the campus restaurants in search of leftover food and, at the Biotery Center, collected wood shavings residue, which is used to house the rats used in experiments. The support from the Unicamp Ecological Park was also essential in obtaining a third residue from the composition: debris from tree and lawn pruning.

The Biology student, whose research was financed by CNPq, says that setting up the patio to house the compost bins required additional effort. A relatively large space is generally required for work to be efficient. The process encompasses four different treatments – each with three repetitions – which generated 12 piles (or windrows) of organic fertilizer.

An important item in the transformation is climatic conditions, as heat and humidity are essential for degradation, which can therefore take more or less time. In the compost bin set up at Unicamp, the average time varied from five to six months. Aida Mahmoud also carried out a survey of the fauna in the compost bins, since the presence of animals is important in the degradation process. “This is a positive aspect, as it means that the windrow is not suffering from compaction, which could cause a bad smell, and also that it is not producing leachate, a toxic substance”, she explains.

Now, the research continues with tests on so-called indicator plants, in order to determine the quality of the compound and its chemical components, with plans to make comparisons with the product already used on campus. Tests will be carried out with organic fertilizer in different concentrations, evaluating twinning and plant development.

Aida intends to refine the calculation of the economic advantages of the process, but immediately remembers the elimination of the cost of transporting the material to landfills. The IB graduate administered a questionnaire to canteen owners. “Recycling and composting are known to 99% of traders and everyone was willing to donate their leftover food”.