Durval Rodrigues de Paula Junior

Uso de lodo de esgoto estabilizado em um solo decapitado: I - atributos físicos e revegetação

A disposicao do lodo de esgoto, estabilizado e tratado, em solos tem se mostrado uma alternativa viavel, uma vez que pode ser feita com baixo custo e sem provocar impactos negativos, contribuindo tambem para o restabelecimento das caracteristicas originais de alguns solos que sofreram processos de degradacao. Com o objetivo de avaliar o uso de dosagens (0, 20, 40 e 80 Mg ha-1) de um composto orgânico de lodo de esgoto e residuos de rocagem na recuperacao de um solo decapitado, pelo seu efeito nos atributos fisicos do solo e revegetacao com especies nativas, realizou-se um experimento em Mogi-Guacu - SP. Concluiu-se que as dosagens de lodo de esgoto compostado nao modificaram os atributos fisicos analisados no solo do local e que a altura e o diâmetro medio das plantas do reflorestamento escolhido nao sofrem influencia das dosagens crescentes de composto de lodo de esgoto no solo decapitado, independentemente do grupo sucessional.SUMMARY : USE OF STABILIZED SEWAGE SLUDGE ON A HUMUSLESSSOIL. II - CHEMICAL PROPERTIES AND REVEGETATION The disposal of sewage sludge and other organic waste on the soil seems be an alternativefor the public sector since this can provide nutrients for the growth and maintenance of plantspecies that constitute the urban systems of green areas. This experiment was conducted inMogi Guacu, State of Sao Paulo to evaluate the effect of doses (0, 20, 40 and 80 Mg ha -1 ) of anorganic sewage sludge compost and grass residue on the recovery of a humusless soil, particularlyon the soil chemical properties and revegetation with native species. At a dose of 80 Mg ha -1 sewage sludge compost an increase was observed in the level of P, Ca, Mg, K, Mg, Fe, and soilpH, with positive influence on fertility and unaltered soil organic C content. The index of soilcover by tree canopies was not influenced by increasing doses of sewage sludge compost onhumusless soil.Index terms: Solid waste, compost, degraded soil, reforestation.

Avaliação do desempenho de dois sistemas modulares no tratamento anaeróbio de esgotos em comunidades rurais

This research work introduces an alternative of low cost and easily installable system for treatment of wastewater applied to small communities. These experiments were developed at Experimental Field of Agricultural Engineering College (AEC/UNICAMP). The total volume produced at AEC is 20 m3 day-1, and half part was treated by modular systems. The first system line (A) is composed by an UASB reactor (Upflow Anaerobic Sludge Blanket) followed by two Anaerobic Filters and the second system (B) line is composed by a kind of reactor called CAR (Compartmented Anaerobic Reactor) and it is followed by two Anaerobic filters too. Both systems were handled from December of 2002 through February of 2004 totalizing 30 sample collections. It was concluded under comparation that both system performances were similar and obtained satisfactory results. Medium grades of efficiency in remotion of sedimentable solids, total suspended solids and CDO (Chemical demand of oxygen) obtained in modular system (A) were 99.58%; 94.33% and 67.30% respectively. Modular system (B) showed a remotion of 99.49%; 93.34% and 70.45% to the same evaluation parameters. Both modular systems demonstrated adequate and viable to promote a sanitary treatment of wastewater produced in small communities.