Tratamento de lodos de tanques sépticos por cocompostagem para os municípios do semiárido paraibano: alternativa para mitigação de impactos ambientais.

Abstract

The use of septic tanks, is still wide in Brazil and in other countries, consequence of the low covering indexes in sanitation and of the pertinent advantages to this technology type. In states of Paraíba, in cities of small and medium load of the semiarid, usually the septic tanks, multichamber of collective use, constitute the only form of treatment of sewages. The objectives of this work were to evaluate the co-composting, as viable technological alternative to the treatment of sludges of septic tanks multichamber of collective use for cities of small and medium loads of the semiarid paraiban; to verify the potentiality of the domiciliary organic solid waste to the co-compostagem and to delineate strategies that allow to the surmountion of the rejection of originated products of sewage sludges. The work was accomplished in the period of august from 2005 to june of 2008. The sludges were collected in different chambers of septic tanks collective of the cities of Cabaceiras, Caraúbas and Queimadas and they were submitted to the natural drying. The domiciliary organic wastes were collected in the generating sources (homes) in Cabaceiras, Caraúbas and Queimadas and previously triturated. The experiment consisted of four treatments, with three repetitions, totaling 12 reactors. These of cylindrical configuration in polyethylene of 100L of capacity. Each reactor was fed with 50 substratum kg with variable composition in function of the sludge fraction: 0%, 10%, 20% and 30%. The physical analyses, chemistries and biological they weekly happened, the manual turning, three times a week and the temperature level was monitored daily. To total destruction of helminth eggs it was reached in period differentiated in function of the sludge fraction (14, 28, 35 e 63 days). The medium transformation of 54,06% of sludges in biosolids class A and class B, with favorable characteristics to the use in agricultural cultures in 91 days, expressed the reach of the objectives of the present researches. Indicating success of the chosen treatment for the sludges sewage: the stabilization and higienização were reached.The co-composting it constitutes a viable alternative to the treatment of sludges of septic tanks multichamber of collective use for the cities of small and medium loads of the semiarid paraiban, for assisting to the beginnings of the sustainable and the effective legislation. The process of Environmental Education contributed to the surmountion of the rejection of originated compositions of sludges and the articulation among the sections of the society.