Análise do potencial tóxico dos resíduos sólidos orgânicos de uma escola pública em Campina Grande-PB.

Abstract

Municipal solid waste are composed of large amounts of toxic materials to the environment and public health. Regarding the organic solid waste, they are easily degradable and may be classified as non-hazardous waste. However, when these waste are not segregated at the source, they can aggregate toxic particles and to change from nontoxic to toxic condition. In this context, this study aims to evaluate the toxic potential of organic solid waste in a public school of Campina Grande-PB. Toper forming the experiment did the construction and instrumentation of a benchtop bioreactor, made of PVC pipe, with a volume of 0.028 m3 and dimensions of 0.90m and 0.20m in height and inner diameter, respectively. The bioreactor was filled with organic solid waste from the restaurant at the State School of Middle Teaching Severino Cabral. The monitoring was carried out from December 2013 to November 2014.The samples were collected every two weeks to carry out the pH, total alkalinity, ammonia nitrogen, phytotoxicity and leaching and solubilization tests. The results indicated that the organic solid waste was classified as hazardous waste (Class I)because they contain concentrations of metals such as Al, Fe and Mn above the established by ABNT/NBR 10,004/2004. However,these metal high concentrations did not influence the rate of germination and growth of tomato (Lycopersicon lycopersicum) and cabbage (Brassica oleracea) seeds along the time tracking of waste in bioreactor. It was also observed in relation to the toxicity of nitrogen ammoniacal which due to the low pH levels of the waste in the form of ammoniacal, it prevailed in the bioreactor the ionized form (NH4+) that is non-toxic. Principal Component Analysis indicated the formation of groups, relationship and similarity between the parameters measured during the waste biodegradation process. The identification of heavy metals above the legislation limits confirmed the toxicity in the waste of the school.