Analysis of physical, chemical and biological parameters necessary for the quality of organic fertilizer from the composting process carried out at the State University of Paraíba, PB

Abstract

The present work is the result of a university extension project, carried out at the Padre Cornelio de Boer Municipal School, in Campina Grande - PB, with 66 students from pre-school classes II, 2nd, 3rd and 5th year of Elementary School I. The organic solid waste was sorted, mixed with leaves, weighed and, in three concrete composters, disposed in the decentralized solid waste treatment system (SITRADERO), located in the annex of the laboratory of the Extension and Research Group in Management and Education of the Department of Biology (GGEA/DB/UEPB). From then on, monitoring (for a period of 104 days) was carried out of several parameters, including daily (temperature), weekly (total solids, humidity, aeration, pH, mesoinvertebrates and organic carbon) analyzes, beginning and end of the experiment (helminth eggs) and only at the end of the composting process (potassium, phosphorus and nitrogen), to characterize the sanitization of the compost (organic fertilizer) in formation. As a result of the system monitoring, it was observed that the values ​​obtained for almost all analyzes were in accordance with Normative Instruction No. 25, of July 23, 2009, from the Ministry of Agriculture, Livestock and Supply for single fertilizers, the final values were removed: pH (8.05), SVT (36.18%), TOC (20%), Humidity (32%), Helminth eggs (0.0 eggs/gst), Total nitrogen (1.3) and Phosphorus (4.2), the values ​​obtained for potassium (0.80) do not reach the values ​​suggested by Normative Instruction No. 25. At the end of the monitoring period of the composting system, it was disassembled, since all physical analyzes, products and biologicals indicated stabilization. Then, the screening and classification of the compost was carried out. The compost removal was done with the aid of basins and shovels, followed by sieving in 4 mm and 2 mm mesh sieves for classification. The compound composed of three classes: tailings, bran and powder according to the Normative Instruction of the Ministry of Agriculture, Livestock and Supply nº. 25, of July 23, 2009.