Directrices para la remediación de los suelos contaminados con hidrocarburos

Changes in restored soils subject to weathering and their implication in Mexican environmental regulations

“…In regards to the quantif ication of Total Petroleum Hydrocarbons (HTP), it was found that the control soil (T2) was not contaminated with hydrocarbons and, in the results of Tukey test for this parameter, T2 presents signif icant differences with respect to TR2 and TP2 (HSD > 33.4983), but no signif icant differences were observed when comparing the values of TR2 and TP2 (HSD < 33.4983); though, it should be noted that all values are below the MLP of Mexican regulations in matters of the hydrocarbons in soils (SEMARNAT, 2013). In similar studies, Khalladi et al (2009) and Chan-Quijano et al (2015) mentioned that surfactant treatment gave good results for soils contaminated with the light fraction of hydrocarbons. It has also been reported that this process has better selectivity in clay soils without presenting an increment in the formation of aggregates and textures (Li et al, 2016); nevertheless, there are some disadvantages for this method: for example, it promotes the removal of organic matter and when cationic surfactants are employed, the salt content is usually increased, if mixed surfactants are used, the dragging of other cations is promoted and the percentage of organic matter is decreased (Mao et al, 2015).…”

“…On the other hand, it is advisable to apply in the studied soil sowing techniques designed for urban and arid areas, for example, double digging or deep seeding, the latter is to leave the root as close to the water table in order to achieve a deeper anchorage and the plant does not have stress for lack of water; this methodology has also been successfully applied to restore underground aquifers and contaminated soils (Rahman and Hasegawa, 2011;Ukiwe et al, 2013;Chan-Quijano et al, 2015). Regarding the restoration of tropical areas, favorable results have been achieved with the use of plants with a small crown diameter and that can be managed by pruning.…”

“…One of the Mexican states with a high degree of degradation of its ecological environment is Tabasco; this area has great natural resources reserves that have favored for decades diverse economic activities like forestry, livestock, and agriculture, as well as natural gas and crude petroleum extraction activities. Although, the latter has also contributed to the degradation of the environment and constant social claims for spills (Chan-Quijano et al, 2015). Different studies agree that the changes in the soil of tropical regions in México are mainly associated to three factors: the f irst one is correlated to the type of climate (floods and droughts), the second includes anthropogenic activities as intensive crops, urbanization, and oil industry and, the third factor involves the changes in soil use (Pérez-Vidal et al, 2010;Palma-López et al, 2017).…”

“…In this sense, environmental management of agricultural and urbans zones for forest development is not a new issue, most studies have established which kind of plant to sow or to induce based on satellite spatial modelling studies and, in areas where industrial and agricultural activities are combined (Oldoni et al, 2019;Damian et al, 2020); other studies like that of Angelopoulou et al (2019) found that these studies must be constantly updated due there are changes in the soils by civil works such as roads and flood protection embankments, which are added to the restored soils, Pannecoucke et al (2020) and Kiani et al (2020) mentioned that the horizons of the soils are homogenized, so the reading determined by the satellite can vary, they also determined that fertility conditions are usually different from those reported in neighboring areas; some phytoremediation works coincide in the success of these technologies, based on establishing studies of soil fertility conditions and the type of pollutant present, on the one hand, seeks removal, but on the other, biomagnif ication must be prevented and, in the case of sites with presence of hydrocarbons, it is recommended studying the water potential by means of the water repellency (Chan-Quijano et al, 2015;Marín-García et al, 2016;Domínguez-Rodriguez et al, 2020) In this context, although current Mexican economic strategies are committed to the hydrocarbon sector and the rescue of the agricultural sector, little attention has been paid to restored soils with the presence of residual hydrocarbons in which they are going to implement programs in these two sectors, a specif ic topic is the Environmental Base Lines (LBA) of the energy sector, this tool was recently created and is based on the study of all environmental impacts related to pollution spills from the hydrocarbon sector, especially in areas where operations of the private sector are required. It has been noted that to establish the environmental impact in restored soils, evaluations are f irstly based on the parameters described in NOM-021-SEMARNAT-2000 and, later, a comparison is made with literature data.…”

Fertility Deterioration in a Remediated Petroleum-Contaminated Soil

“…Many researchers consider that bioremediation methods are superior to physical-chemical methods for cleanup of hydrocarbon-contaminated soil (see for example, [9,10]). Although physical-chemical treatments are widely used due to the short time required for the reduction of high hydrocarbons concentrations, many researchers have considered that the effects on soil fertility are very negative [11][12][13].…”