The goal of the present research work was to assess the management of sewage sludge (SS) by composting using fermented water hyacinth (WHferm) as an amendment. The water hyacinth was fermented, and a higher production of volatile fatty acids (VFAs) (782.67 mg L(-1)) and soluble organic carbon (CSOL) (4788.34 mg L(-1)) was obtained using a particle size of 7 mm compared to 50 mm. For composting, four treatments (10 kg fresh weight each) were evaluated: treatment A (100 % SS + 0 % WHferm), treatment B (75 % SS + 25 % WHferm), treatment C (50 % SS + 50 % WHferm), and treatment D (25 % SS + 75 % WHferm). The WHferm added to SS, especially in treatments C (50 %) and D (75 %), increased the initial contents of organic matter (OM), organic carbon (CORG), CSOL, the C/N ratio, and the germination index (GI). The heavy metal content (HMC) (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) at the beginning was below the maximum allowed by USEPA regulations. All of the samples were free of Salmonella sp. from the beginning. The reduction of the CORG, CSOL, total Kjeldahl nitrogen (TKN), and C/N ratio indicated the degradation of the OM by day 198. The treatments with WHferm (B, C, and D) yielded higher values of electrical conductivity, cation exchange capacity, and GI than SS at day 198. No significant differences were observed in GI among the treatments with WHferm. The fecal coliforms were eliminated (<3 MPN g(-1)) and the helminths were reduced to ≤5 eggs/2 g during the process. The competition for nutrients and the presence of suppressive fungi of the genera Penicillium, Rhizopus, Paecilomyces (penicillin producers), and Fusariella isolated from the compost may have promoted the elimination of pathogens since no thermophile temperatures were obtained. WHferm as an amendment in the composting of SS improved the characteristics of the final product, especially when it was used in proportions of 25 and 50 %. An excellent product was obtained in terms of HMC, and the product was B class in terms of pathogens.

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The demographic, industrial and agricultural growth of recent decades in the State of Mexico has caused a considerable increase in groundwater extraction and the overexploitation is mainly due to drinking water, because it is the supply source for the two densely populated zones in the country: the metropolitan areas of Toluca City and Mexico City and its conurbation. In this work, 49 groundwater sources of drinking water were analyzed in two sampling periods (dry and rainy seasons). According to the Electric Conductivity data, 67% of the samples in the dry and 63% in the rainy season presented weak mineralization and the rest of the samples showed medium mineralization. In addition, the values of hardness showed that the water had good quality, with the exception of 3% of the wells in the rainy season, which had medium quality. The corrosion coefficient showed that two samples in the dry season and four in the rainy season had aggressive characteristics that might damage the extraction and distribution networks. The concentrations of major ions (measured by ionic chromatography) in both sampling periods showed this relative abundance: Na + >Mg 2+ >Ca 2+ >K + =HCO 3 ->>Cl ->SO 4 2-. It was found that the HCO 3 -concentration increased with the groundwater flow in the area. Moreover, it was also possible to establish the principal species in solution and to corroborate the hydrochemical change in the area of study. Although there continues to be clear predominance of the Mg-Na-HCO 3 type, the Na-HCO 3 facies showed a progressive increase.

Metal presence is a serious pollution problem in natural or treated water. The water hyacinth (Eichhornia crassipes) is an aquatic plant known for its high capacity to absorb metals. However, to use water hyacinths in a sustainable pollution removal process, the parameters that affect the process of metal absorption and the disposal of the contaminated organic matter must be studied; these being the aims of this work.Water hyacinth assays were carried out in distilled water and the influence of Mn 2+ initial concentrations (C o : 10, 50, 100mg/L) and initial pH (pH o : 3, 5, 7) were analyzed. Parameters such as pH, electric conductivity (EC), and residual Mn 2+ were also measured. At the end of every assay, Mn was quantified in the different sections of the water hyacinth (root "R", petiole "P" and leaf "L") by atomic absorption spectrometry, and the presence of metal aggregates was detected by TEM microscopy.E. crassipes did not neutralize its growing medium. The EC was not a good control parameter for absorption, increased with time. The water hyacinth was capable of efficiently removing Mn 2+ from the solutions. It can be seen two phases of absorption (a rapid one followed by a slow absorption phase nearly linear). With increasing C o , the absorbed Mn Finally, aggregates of Mn 0 were detected in nanometric size (between 5 and 20nm) in all the sections, being suggested that E. crassipes can turn as raw material in nanotechnology.

Bacteria are microorganisms found in all environments and they fulfill various tasks in ecosystems, however, some can affect the human population causing outbreaks of disease and death.