Two processes are used to stabilize organic wastes: composting and vermicomposting.There are no studies in the literature showing which process is most effective over the short term. In this study, 3 organic wastes were composted and vermicomposted for 90 days, and the parameters pH, effective cation exchange capacity, total organic carbon, total Kjeldahl nitrogen, Ptotal, E4/E6 ratio, hydrophobicity and aromaticity indexes were determined. In all experiments, vermicomposted materials showed higher stability, proving a superior tool for stabilization of these organic wastes.

A method using ultrasonication extraction for the determination of 17 polycyclic aromatic hydrocarbons (PAHs), selected by the USEPA and NIOSH as "consent decree" priority pollutants, in soil by High Performance Liquid Chromatography (HPLC) was studied. Separation and detection were completed in 20 min with a C18 columm, acetonitrile-water gradient elution and ultraviolet absorption and fluorescence detections. The detection limits, for a 10 µL of solution injection, were less than 9,917 ng/g in UV detection and less than 1,866 ng/g in fluorescence detection. Several organic solvents were tested for extraction of the 17 PAHs from soils. Acetone was the best solvent among the three solvents tested, and the order of the extraction efficiencies was: acetone>methanol>acetonitrile. Ultrasonication using acetone as solvent extraction was used to evaluate the biodegradation of those compounds in contaminated soil during a vermicomposting process.

The main objective of this research was the characterization of the humic fractions isolated from vermicomposting, originating from cattle manure and treated with Eisenea foetida or Lumbricus rubellus, during 3 and 6 months. Elemental analysis and Infrared and UV-vis spectroscopy were used for their characterizations. The results obtained shown that both humic acids are very similar, but six-month humic acid shown lower percentage of organic material than three month humic acid. The spectroscopy analysis shown that the humic acid studied can be compared with other humic acids reported in the literature. By comparing both vermicomposts, the one produced in three months presents a great potential as fertilizer and it is more economical than the vermicompost produced during a six month period.

The herbicides are being used in huge quantities for various porpouses. Once the herbicide finds its way into the environment, a major part of it comes in contact with soil. Humic substances are major organic constituents of soil. These substances may interact with herbicides in different modes and adsorption is probably the most important one. Adsorption will control the quantity of herbicide in the soil solution, and determines its persistence, leaching, mobility and bioavailability. In this work we studied the interaction between the herbicide 2,4D and soil in the presence and absence of organic matter. The methodology utilized for the determination of 2,4D was gas chromatography with eletron capture detector. The behavior of 2,4D was evaluated through Freundlich isotherms. It was verified that the herbicide 2,4D has a large adsorption in the humic acid .

Atrazine and alachlor herbicides are widely and extensively used in agriculture for the control of a variety of weeds. These herbicides are quite mobile in soil and there is a concern that they may contaminate the environment, specially surface and ground water and soils. The results suggest that alachlor and atrazine present similar behavior in the environment, but alaclhor dissipates with greater rate.

Este trabalho teve como principal objetivo o desenvolvimento de uma metodologia para a análise simultânea de pentaclorofenol (PCP) e hexaclorobenzeno (HCB) em água natural de subsuperfície proveniente de uma região afetada por resíduos industriais (São Vicente-SP), onde a maior parte da população se utiliza de poços pouco profundos para o abastecimento. A extração líquido-líquido apresentou bons resultados quanto à recuperação e repetibilidade do método. Para o nível de fortificação de 10 ng L-1 de PCP e HCB a recuperação situou-se entre 81.5% e 103.0%, com um desvio padrão relativo de 2.4% a 4.1%. A determinação dos analitos foi efetuada por GC-ECD e/ou GC-MS. Adicionalmente, o limite de quantificação do método foi de 5 ng L-1 para PCP e 2 ng L-1 para HCB, valores que estão abaixo do nível máximo permitido pelas diretrizes da Comunidade Européia para resíduos de pesticidas em água potável.

This paper presents the development of a methodology for the simultaneous analysis of pentachlorophenol and hexachlorobenzene in natural waters affected by industrial residues, as its principal goal. Samples were collected in Quarentenário, São Vicente city, where most of the population utilize wells for their supply. The liquid-liquid extraction employed to remove PCP and HCB from the matrix for further identification and quantification, showed very good recovery and repeatability. The recovery range was between 81.5% and 103.0%, with a relative standard deviation of 2.4% and 4.1% for a fortification level of 10 ng L-1. In addition, organochlorine compounds were determined by GC-ECD and/or GC-MS. The limit of quantification was 5 ng L-1 for PCP and 2 ng L-1 for HCB, which are below the maximum level allowed by the EC directives for pesticide residues in drinking water.