SUSTAINABLE DEVELOPMENT BY RECYCLING WASTE AS BIOFERTILIZER COMPOST

Composting represent the biological oxidative decomposition of organic constituents in wastes, under controlled conditions, which allow development of aerobic microorganisms that convert biodegradable organic matter in a final product (compost, CO2, H2O, mineral ions) sufficiently stable for storage and application, without adverse environmental effects. Our research established the possibility of recycling, by composting, vegetables waste with sawdust and sewage sludge in order to obtain compost, a biofertilizer with a higher nutritive value for plants and grains, and a very good amendment of the physical and chemical properties of soil. The composting process was monitored, by tests performed weekly and established interesting correlations between the chemical structures of components of wastes and their biodegradation compounds during composting process. The FT-IR spectra showed a decrease of the absorbance of the easily assimilable compounds that are predominant in the initial mixtures and appearance of some other chemical structures probably of aromatic and peptidic origin. Germination index (GI) was performed as an indicator to evaluate compost phytotoxicity and stability. The results confirm that the presence of sawdust and sewage sludge (an extra source of sugars, having lipids and microorganisms forming enzymes) improves the biodegradation process.