scholarly journals Groundwater Quality of Southeastern Brazzaville, Congo

2010 ◽  
Vol 7 (3) ◽  
pp. 861-869 ◽  
Author(s):  
Matini Laurent ◽  
Moutou Joseph Marie

The groundwater in southeastern Brazzaville (Congo) was analyzed for their fluoride contents and others related parameters in rainy season. The fluoride contents in water samples (wells and spring) can be gather in three classes in the study area: low, optimal, high. Fluoride concentration in water samples presents a low significant correlation with Ca2+. This suggests that fluoride in the groundwater come from fluoride-bearing minerals such as CaF2(fluorite). Maps were drawn to show the geographical distribution of EC, Ca2+, Mg2+and F-. Factor analysis and cluster analysis were applied to the dataset. Factor analysis resulted in four factors explained 76.90% of the total groundwater quality variance. Factor 1 (hardness of the groundwater) includes total hardness, the concentration of K+, Ca2+and pH. Factor 2 (low mineralization of the groundwater) includes concentrations of TDS, Cl--, SO42+and EC. Factor 3 (anthropogenic activities with the impact of agricultural fertilizers, farming activities, domestic wastewater, septic tanks) includes concentrations of Na+and NO3-. Factor 4 (weathering of calcium minerals) includes concentrations of F-. For cluster analysis, Ward’s method and the Euclidean distance were used. The findings of the cluster analysis are presented in the form of dendrogram of the well water sites (cases). The discriminating parameters between clusters have been highlighted from the Student test. In majority, they are in accordance with those highlighted by factor analysis.

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1077
Author(s):  
Ana M. Córdova López ◽  
Althiéris de Souza Saraiva ◽  
Carlos Gravato ◽  
Amadeu M. V. M. Soares ◽  
Renato Almeida Sarmento

The present study aims to use behavioral responses of the freshwater planarian Girardia tigrina to assess the impact of anthropogenic activities on the aquatic ecosystem of the watershed Araguaia-Tocantins (Tocantins, Brazil). Behavioral responses are integrative and cumulative tools that reflect changes in energy allocation in organisms. Thus, feeding rate and locomotion velocity (pLMV) were determined to assess the effects induced by the laboratory exposure of adult planarians to water samples collected in the region of Tocantins-Araguaia, identifying the sampling points affected by contaminants. Furthermore, physicochemical and microbiological parameters, as well as the presence of inorganic compounds (dissolved aluminum, total barium, total chloride, dissolved iron, total fluoride, total manganese, nitrates, nitric nitrogen, total sulfate, total zinc) and surfactants, were determined on each specific sampling point. The behavioral biomarkers (feeding rate and pLMV) of the freshwater planarians were significantly decreased when organisms were exposed to water samples from four municipalities (Formoso do Araguaia, Lagoa da Confusão, Gurupi and Porto Nacional), sites of the Tocantins-Araguaia hydrographic region—TAHR. Both behavioral biomarkers decreased up to ~37–39% compared to organisms in ASTM medium only. Our results showed that these behavioral biomarkers can be used for fast screening monitoring of environmental samples of freshwater ecosystems, since a decrease in feeding rate and locomotor activity was observed in sites impacted by anthropogenic activities. However, the absence of effects observed in some sampling points does not represent the absence of contamination, since several other classes of contaminants were not determined. In these negative results, the absence of deleterious effects on behavioral biomarkers might only be indicative that the potential presence of contaminants on such sites does not significantly affect the performance of planarians. This fast screening approach seems to be useful to determine contaminated sites in freshwater ecosystems for biomonitoring purposes. This knowledge will help to develop biomonitoring programs and to decide appropriate sampling sites and analysis.


Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1321 ◽  
Author(s):  
Muhammad Aleem ◽  
Cao Shun ◽  
Chao Li ◽  
Arslan Aslam ◽  
Wu Yang ◽  
...  

The industrial augmentation and unguided anthropogenic activities contaminate water sources in most parts of the world especially in developing countries like Pakistan. High concentration of pollutants in groundwater affects human, soil, and crop health badly. The present study was conducted to investigate groundwater quality for drinking and irrigation purposes in an industrial zone of Pakistan. A GIS tool was used to investigate the spatial distribution of different physico-chemical parameters. In this study, the average results exceeding World Health Organization (WHO) and National Environmental Quality Standards (NEQS) were found for pH 7.84, total dissolved solids (TDS) 1492 mg/L, phosphate 0.51 mg/L, dissolved oxygen (DO) 9.92% saturation, F-coli 6.48 colonies/100 mL, Na+ 366 mg/L, HCO3− 771 mg/L, sulfate 251 mg/L, chlorides 427 mg/L, total hardness (as CaCO3) 292 mg/L, electrical conductivity (EC) 2408 μS/cm, iron (Fe) 0.48 mg/L, chrome (Cr) 0.50 mg/L, arsenic (As) 0.04 mg/L, total phosphorus (TP) 0.17 mg/L, sodium adsorption ratio (SAR) 9.76 (in meq/L), residual sodium carbonate (RSC) 9.28 meq/L, % ion balance 14.4 (in meq/L), percentage sodium ion (% Na+) concentration 58.9 meq/L, and water quality index (WQI) 69.0. The trend of cations and anions were (in meq/L) Na > Mg > Ca > K and HCO3 > Cl > CO3 > SO4 respectively. Although the results of the present study showed poor conditions of the groundwater for drinking as WQI but and irrigation purposes as SAR, it needs to improve some more conditions for the provision of safe drinking water and irrigation water quality.


2020 ◽  
Vol 51 (2) ◽  
pp. 299-318
Author(s):  
Tomás Bragulat ◽  
Elena Angón ◽  
Alberto Giorgis ◽  
José Perea

Objective: Identify and characterize the beekeeping systems of La Pampa (Argentina) using multivariate techniques based on the main structural, productive and economic characteristics. Methodology: The data was collected through a random survey of 80 beekeepers. The classification and description of the apicultural systems was based on a multivariate sequence comprising three stages: review and selection of variables, factor analysis and cluster analysis. Results: Factor analysis revealed that the size of the farm and the productive and economic performance of beekeeping jointly explained 66% of the variability. Through cluster analysis, three types of beekeeping have been identified: (i) Subsistence beekeeping grouped 55% of the farms, mainly characterized by small sizes and low productive and economic yields. (ii) Industrial beekeeping concentrated 54% of production in 15% of farms, mainly characterized by large sizes and high productive and economic yields. (iii) Commercial beekeeping grouped 30% of the farms, mainly characterized by high productivity with intermediate sizes. Limitations: The study has been carried out on a few farms due to the difficulty of obtaining answers to all the variables included in the survey. Practical implications: Beekeeping in La Pampa is generally a highly heterogeneous complement of income or family subsistence, with low productivity and low input use. Subsistence beekeeping is a socially relevant system for its contribution to family employment and income in rural areas. Industrial beekeeping is oriented to the export market and has a more competitive scale. Commercial beekeeping is situated on an intermediate scale.


e-mentor ◽  
2021 ◽  
Vol 92 (5) ◽  
pp. 81-90
Author(s):  
Kamil Brodnicki ◽  

The article presents the impact of remote work, resulting from the COVID-19 pandemic, on the functioning of Scrum teams. Attempts have been made to analyse the positive and negative aspects of remote work. The article also looks at the impact of remote work on the level of communication and efficiency of Scrum teams. For this purpose, the author conducted research on a sample of 40 organisations that declared to use Scrum methodology, using 187 questionnaires as the research material. The study was carried out at the turn of April and May 2021 and was carried out using the CAWI technique. The obtained results were analysed using the Principal Component Analysis and Cluster Analysis methods, and enable defining a picture of an organisation’s readiness to work remotely. In addition, they also allowed for an assessment of how the infrastructure used for remote work communication translates into the organisation of Sprint meetings. This paper presents conclusions aimed at counteracting the observed irregularities detected during the tests. At the end, the author proposes solutions that could improve communication within Scrum teams, with remote work in mind.


2021 ◽  
Author(s):  
Luka Vucinic ◽  
David O'Connell ◽  
Donata Dubber ◽  
Patrice Behan ◽  
Quentin Crowley ◽  
...  

<p>Lowland karst aquifers in Ireland are extremely complex to understand and are considered to be highly vulnerable to pollution (e.g. low-lying karst catchments exhibit a lot of surface water – groundwater interactions which makes them very susceptible to direct contamination). These aquifers are impacted by multiple contamination sources on land (in particular, rural sources from agriculture and on-site domestic wastewater effluent) which makes their protection and management challenging. Human wastewater effluent is identified as significant threat to groundwater quality in such lowland Irish karst environments, since approximately one-third of the population in Ireland is relying on decentralized wastewater treatment systems for the treatment of domestic wastewater. However, it is difficult to distinguish between human wastewater effluent and agricultural pollution impacts on karst aquifers using only traditional water quality parameters or any single environmental tracing method. Hence, the impact of microbial and chemical contaminants of human wastewater origin on groundwater quality must be assessed using a multiple-tracer approach, ideally targeting source-specific tracers. This paper presents an overview of the results obtained during the research conducted throughout the last several years at nine karst catchments in Ireland using a range of methodologies in order to determine and quantify domestic wastewater pollution impacts on karst springs. Microbial pollution was assessed using flow cytometric fingerprinting and faecal indicator bacteria, while chemical pollution impact assessment included the analysis of fluorescent whitening compounds (FWCs; well-known indicators of human contamination since their origin is mostly from laundry detergents), specific anion ratio signatures (Cl/Br), quantification and identification of microplastic particles using Fourier-transform infrared spectroscopy (FTIR), and faecal sterol and stanol profiles and ratios. A thorough analysis of the results obtained using a multiple-tracer approach has been conducted and methodologies have been evaluated in terms of applicability and sensitivity in a range of different karst catchments. The ability of these methodologies and techniques to determine and quantify human faecal pollution impacts on karst springs will be discussed. The results show a significant correlation between microplastic particle counts and detected FWCs signals at different springs, which helps to understand the contribution of household-derived contaminants to this environmental problem. Moreover, our results indicate that faecal sterols and stanols can be useful faecal source tracking method in karst aquifer systems despite the fact that concentrations of sterols and stanols of interest were usually low which makes the interpretation of results challenging.</p>


2019 ◽  
Vol 131 ◽  
pp. 01086
Author(s):  
Menghui Qiu ◽  
Zhijing Zhao

Consumers are the most direct stakeholders of food safety, and their effective participation is the key to the social Co-governance of food safety. Based on the specific behaviors of Chinese consumers participating directly and indirectly in the social Co-governance of food safety, using the data of 350 consumers’ behavior survey and factor analysis and cluster analysis, this paper extracts two kinds of behavior models of Chinese consumers participating in the social Co-governance of food safety, namely, consumption choices model and environment improvement model. It is found that Chinese consumers are inclined to adopt the “environment improvement” model at this stage, which is the inevitable result of the current food safety pressure in China. The government should formulate corresponding policies to better guide consumers to participate in the social Co-governance of food safety.


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