RESUMEN
The regulation of the anthropogenic load on waterbodies is carried out based on water quality standards that are determined using the threshold values of hydrochemical indicators. These applied standards should be defined both geographically and differentially, taking into account the regional specifics of the formation of surface water compositions. However, there is currently no unified approach to defining these regional standards. It is, therefore. appropriate to develop regional water quality standards utilizing modern technologies for the mathematical purpose of methods analysis using both experimental data sources and information system technologies. As suggested by the use of sets of chemical analysis and neural network cluster analysis, both methods of analysis and an expert assessment could identify surface water types as well as define the official regional threshold values of hydrochemical system indicators, to improve the adequacy of assessments and ensure the mathematical justification of developed standards. The process for testing the proposed approach was carried out, using the surface water resource objects in the territory of the Republic of Tatarstan as our example, in addition to using the results of long-term systematic measurements of informative hydrochemical indicators. In the first stage, typing was performed on surface waters using the neural network clustering method. Clustering was performed based on sets of determined hydrochemical parameters in Kohonen's self-organizing neural network. To assess the uniformity of data, groups in each of the selected clusters were represented by specialists in this subject area's region. To determine the regional threshold values of hydrochemical indicators, statistical data for the corresponding clusters were calculated, and the ranges of these values were used. The results of testing this proposed approach allowed us to recommend it for identifying surface water types, as well as to define the threshold values of hydrochemical indicators in the territory of any region with different surface water compositions.
Asunto(s)
Contaminantes Químicos del Agua , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente/métodos , Calidad del Agua , Análisis por ConglomeradosRESUMEN
Today, Ukraine is far from European standards, and the country's waste management system remains confronted with environmental and technogenic problems, with 7 % of the territory occupied by landfills. Most settlements in Ukraine do not have solid waste management programs or sanitation schemes. Landfills, and especially municipal solid waste dumps, are significant contributors to air, water, and soil pollution. The objective of this research is to develop a comprehensive understanding of the environmental impact of landfills, to translate them from a descriptive and abstract plane to a mathematical plane, and to identify the sanitary protection zones currently utilized for landfills. The subject of this study is the municipal waste landfill of the Zhytomyr territorial community (Ukraine), a typical Ukrainian landfill operated with minimal environmental protection measures. The authors used an original approach to assess the environmental hazard of a municipal waste landfill, taking into consideration the values of absolute indicators of water pollution for specific physicochemical characteristics; maximum permissible concentrations of the studied indicators; distance from the landfill boundary; the amount of excess of the absolute indicator of pollution compared to the MPC; and the intensity of odor in the landfill. The calculated pollution indicators served as the basis for an integrated assessment of the environmental hazards posed by the municipal waste landfill. The study revealed that the Ot indicator (evaluation of the environmental hazards of municipal waste landfills) depends exponentially on the landfill boundary. Based on the value of Ot, environmental zoning was carried out: according to the calculations and taking into account the monitoring of the environmental condition in the landfill's impact zone, the authors recommended the parameters of environmental zoning on the basis of the Ot value. The purpose of this study is to clarify the sanitary protection zones that are currently used for landfills and solid household waste disposals. The research materials can also be used to create databases on landfills, enabling the development of a plan to manage them as sources of heightened environmental risk.
RESUMEN
Nitrate (NO3-) contamination in groundwater has diverse sources and complicated transformation processes. To effectively control NO3- pollution in groundwater systems, quantitative and accurate identification of NO3- sources is critical. In this work, we applied hydrochemical characteristics and isotope analysis to determine NO3- source apportionment. For the first time, the NO3- source contributions were calculated using hydrochemical indicators combined with multivariate statistical model (PCA-APCS-MLR). The results interpret that chemical fertilizers (58.11%) and natural sources (22.69%) were the primary NO3- sources in the vegetable cultivation area (VCA) which were rather close to the estimation by Bayesian isotope mixing model (SIAR). In particular, the contributions of chemical fertilizers in the VCA differed by only 3.79% between the two methods. Compared with previous approaches e.g. SIAR, the key advantage of the proposed PCA-APCS-MLR model is that it only requires the hydrochemical indicators which can be easily measured. A series of complicated experiments including measurement of isotope data of NO3- in groundwater, monitoring of in-situ pollution source information and calculation of isotopic enrichment factor can be simply avoided. The PCA-APCS-MLR model offers a much more convenient and faster method to determine the contribution rates of NO3- pollution sources in groundwater.
Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Teorema de Bayes , China , Monitoreo del Ambiente/métodos , Fertilizantes/análisis , Isótopos/análisis , Nitratos/análisis , Isótopos de Nitrógeno/análisis , Óxidos de Nitrógeno/análisis , Contaminantes Químicos del Agua/análisisRESUMEN
Burial is applied to dispose of livestock carcasses due to its convenience and cost efficiency despite concerns about groundwater contamination by leachate from burial pits. In particular, the burial method has caused debates about groundwater contamination sources around on-farm livestock burial sites because of pre- and coexisting contamination from livestock production and agriculture. To assess the causes of groundwater contamination around poultry burial pits that were constructed after an outbreak of avian influenza in 2010-11 in Korea, hydrochemical data of groundwater samples from monitoring wells (MWs, n = 14) and household wells (HWs, n = 30) were monitored to differentiate contamination sources. Hydrochemical data indicated that groundwater from MWs is characterized by higher enrichments of inorganic constituents including electrical conductivity (EC), NH4, Ca, Mg, K, SO4, HCO3, Fe(Total), and Mn(Total), but lower concentrations of DO than groundwater from HWs. The combined use of the principal component analysis (PCA) and K-means cluster analysis (KCA) indicated that groundwater in seven MWs was affected by leachate. The parameters such as NH4, Ca, Mg, K, SO4, HCO3, Fe(Total), and Mn(Total) are expected to be useful to identify the impact of leachate on groundwater in agricultural areas. This study suggests that (1) regional hydrochemical characteristics should be assessed to distinguish the effect of livestock burial leachate from other contamination sources and (2) the combined use of PCA and KCA is effective to identify the weakened impact of leachate leakage among overlapping multiple sources and processes of groundwater contamination.