Salinity in soils is a problem that has increased in recent years, in the Mexican southeast one of the main sources associated with these effects is the oil production water, affected congenital water. Although the chemical composition changes between one site and another, it is documented that its components can cause harmful effects on health and ecosystems. To recover the vocation to use recovery areas, different treatments have been established that eliminate standardized parameters, but others that may influence soil quality are not considered. Therefore, two treatment techniques of a soil contaminated experimentally with congenital waters were evaluated, these were; cation exchange and natural attenuation, the evaluation consists in comparing the physical and chemical properties of the control soil, treated and treated after one year, some heavy metals are also determined in all of them. In the results, it is modif ied that the pollutant causes changes in the soil, such as, pH reduction (neutral to acid), porosity (20%), f ield capacity (50%) and organic matter (50%), as well as an increase in salinity (without saline to saline) and densities (10%), it is also increased that the concentrations of Pb, Zn, Ni increase. Na, Fe and V and Ca and K were reduced. Both treatments reduce salinity, but natural attenuation shows better results than cation exchange, mainly in pH, f ield capacity and textures, but with higher concentrations of sodium with respect to the witness in both cases, the metals are below the regulatory limit before and after the treatment, but when compared with control soils a level of increase in V and Pb is noted, because the area is immersed in oil activities, it is advisable to carry out long-term bioaccumulation studies.

No abstract

One of the great challenges of the environmental diagnoses of soils contaminated with hydrocarbons is the optimization of analytical determinations. For this reason, this chapter evaluates the extraction of hydrocarbons by the Soxhlet method through the design of experiments (DOE), variating three different solvents, three soils, and three extraction times. Soil was experimentally contaminated at different concentrations, and hydrocarbons totals relying on conditions organic matter, electrical conductivity, pH and textures, amount of sample, solvents, and NaSO4, were studied. The variables were evaluated by means of an analysis of the Taguchi design and a factorial design, with the results the significant and optimal parameters of the process were determined, which were solvent type and time (10 hours and dielectric constant of 9). Also, the model discards the soil properties. These results will save time and resources, and they reduce errors.

totales del petróleo intemperizados en suelos y sedimentos (Biodegradation modeling of sludge bioreactors of total petroleum hydrocarbons weathering in soil and sediments)

When crude petroleum is spilled onto soil, the oil’s properties have a large influence on the toxicity to soil organisms, the biodegradability of the oil, and potential for long term fertility problems in the soil. Furthermore, these properties of environmental concern are related to the crude’s density, commonly measured as API gravity. Currently, methods do not exist to determine the ºAPI of crude oil in contaminated soil. In this study a novel method is presented for the determination of API gravity in small volumes (< 10 ml) of heavy and extra-heavy petroleum from contaminated soil. Is uses an economical and readily available solvent (diesel + automotive lubricating oil) in a procedure based on the conventional hydrometer method, plus dilution-extrapolation techniques. It was validated with crude petroleum in the 27.1-15.0 ºAPI range, obtaining an excellent correlation with the conventional method (R = 0.996) and an error of less than 0.4% based on specific gravity. Potential applications of this method are discussed for petroleum contaminated soil.