Estudo da composição gravimétrica, física, química e bacteriológica dos resíduos sólidos urbanos da cidade de João Pessoa (PB).

Abstract

The aim of this work was the determination the rate of per capita production, the characterization gravimetric, physics, chemistry and bacteriological of the urban solid waste of the city Joao Pessoa, capital of the state of Paraiba (7°6'54 " of south latitude and 34°51 '47 " of longitude west), looking for to contribute for electric outlet of decisions in the ambit of proposals and alternative solutions in the process of optimization of the use of services, personal, time, transport, costs and mainly the type of treatment and/or final destination of the solid waste of the city. The research was accomplished in the period understood between February and September of the year of 2001. For execution of the work, they were together chosen with EMLUR (Municipal Special Autarchy of Urban Cleaning) six neighborhoods, that represented at that time, on average, 22% (twenty-two percent) of the domiciled total population in the urban zone of the city. During the period of the research they were accomplished in each neighborhood twenty-four samples repetitions for the determination of the rate of per capita production, twelve for the determination of the gravimetric composition and three for the analyses physics, chemistry and bacteriological. The analysis of the results demonstrates that the medium rate ofper capita production is of 0,83kg/inhabitant. day, while in the gravimetric composition the most representative fractions were the organic matter with 53,8%, the plastics with 13,9%, paper & paperboard with 6,2%, metals with 1,9% and glasses with 1,3% (percentage in weight), being verified that, in a general way, these values are inside already of the limits established for other researchers in other Brazilian cities. The physical characterization, chemistry and bacteriological it was accomplished in the fraction organic putrefaction of the urban solid waste in samples collected such end simultaneously with the one of the gravimetrics characterizations. The results show pH values same to 4,80, 75,9% of humidity, 90,9% of STV, 9,1% of STF, 49,4% of COT, 49,4% of DQO and the relationship C/N equal to 26/1, CT of 2,1 x 108, CF of 2,0 x 108, E coli of 2,0 x 107 and E.F of 2,8 x 107 (NMP/g). The physical and chemical characterization of the urban solid waste of Joao Pessoa presented a compatible pH to the of the places researched in the literature, a humidity tenor above the average, needing to be corrected for minor (for ideal strip among 40 to 60%), in case it is used in a possible composting process. The percentile of volatile solids were above the national average, and the medium value of the relationship C/N comparable to the of some of these places, inside of the limits (minimum of 25/1 and maximum of 35/1) more recommended for a fast and efficient composting. The bacteriological analyses showed the discharge contamination for total coliformes of the fraction organic putrefaction of the urban solid waste, in other words, CT of 2,1 x 108 NMP/g. with relationship to the fecal coliformes the analyses showed values in the order of 2,0 x 108 NMP/g. And for E. coli the obtained value m Joao Pessoa/PB was of 2,0 x 107 NMP/g. the value of fecal estreptococos certain was Already of 2,8 x 107 NMP/g.