scholarly journals Hydrogeochemistry and groundwater flow mechanisms in shallow aquifer in Yaoundé, Cameroon

2020 ◽  
Vol 20 (4) ◽  
pp. 1334-1348
Author(s):  
Alain Fouépé Takounjou ◽  
Gloria Takem Eyong ◽  
Dorice Kuitcha ◽  
Robert Kringel ◽  
Wilson Fantong Yetoh ◽  
...  
Keyword(s):  
Chemical Constituents ◽  
Urban Groundwater ◽  
Shallow Aquifer ◽  
Anthropogenic Input ◽  
Multivariate Statistical ◽  
Anthropogenic Inputs ◽  
Groundwater Samples ◽  
Isotopic Analyses ◽  
Flow Mechanisms ◽  
Major Chemical

Abstract Hydrogeochemical processes and flow mechanisms of groundwater in the urban area of Yaoundé were investigated using major chemical constituents, stable isotopes (18O and 2H), and multivariate statistical analysis. Thirty five groundwater samples were collected and analysed for various parameters. Hydrogeochemical evolution visualized with the Gibbs diagram showed that the groundwater is mainly controlled by water–rock interactions. Factor analysis on the other hand identified three major groups of geochemical constituents and showed that weathering and anthropogenic inputs are the dominant factors controlling groundwater chemistry in the study area. Isotopic analyses revealed that oxygen-18 of groundwater (18O = −2.96 ‰ VSMOW) is close to that of rainfall (18O = −2.47), indicating that the groundwater is recharged by rainwater without evaporation. The geogenic composition of urban groundwater in Yaoundé is modified by secondary processes and anthropogenic input.

scholarly journals A statistical approach to evaluate the chemistry and quality of groundwater in Jamankira area, Sambalpur district, Orissa, India

2007 ◽  
Vol 35 ◽  
pp. 43-50
Author(s):  
J. K. Jena ◽  
P. K. Verma ◽  
H. K. Sahoo
Keyword(s):  
Cluster Analysis ◽  
Statistical Approach ◽  
Chemical Constituents ◽  
Total Dissolved Solids ◽  
Sodium Adsorption Ratio ◽  
Residual Sodium Carbonate ◽  
Groundwater Samples ◽  
Sodium Percentage ◽  
Major Chemical

The groundwater quality in the Jamankira area of Sambalpur district was evaluated to determine its hydrogeochemical variability. A total of thirty groundwater samples were analysed for their major chemical constituents. The quality of groundwater was estimated on the basis of total dissolved solids, sodium adsorption ratio, sodium percentage, residual sodium carbonate, and Piper’s trilinear diagram. Cluster analysis was used in the study as a qualitative means for differentiating the groundwater into distinctive types. The cluster analysis shows: 1) Ca-HCO3-SO4-Mg bearing calcium-rich water and 2) Na - K-Cl bearing sodium-rich water in the study area.

scholarly journals Groundwater recharge to the confined aquifer system in the Terai plain of Nawalparasi district, western Nepal: a hydrochemical approach

1998 ◽  
Vol 17 ◽  
Author(s):  
Dinesh Pathak ◽  
G. Krishna Rao
Keyword(s):  
Water Resources ◽  
Groundwater Recharge ◽  
River Water ◽  
Chemical Constituents ◽  
Confined Aquifer ◽  
Aquifer System ◽  
Unconfined Aquifers ◽  
Groundwater Samples ◽  
Tube Wells ◽  
Major Chemical

Groundwater recharge estimate is an essential part of the management of the water resources. The Terai plain of Nepal with multi-aquifer system and a number of river systems need thorough understanding on their interconnection. Groundwater samples from the dugwells, shallow tube wells, deep tube wells, and river water were analysed for major chemical constituents. The chemistry of confined aquifer system is found to be different from the unconfined aquifers. The groundwater recharge to the confined aquifers is therefore believed to be not by vertical infiltration from the shallow aquifers but directly from the palaeo and present river beds. Estimation of groundwater recharge in parts of the Terai plain by rainfall factor warrants rethinking.

Isolation and HPLC Determination of the Chemical Components of Gentianella acuta (Michx.) Hulten

2018 ◽  
Vol 15 (1) ◽  
pp. 21-33
Author(s):  
Ying Wei ◽  
Yongqiao Liu ◽  
Yifan Hele ◽  
Weiwei Sun ◽  
Yang Wang ◽  
...  
Keyword(s):  
Medicinal Plant ◽  
High Speed ◽  
Chemical Constituents ◽  
Folk Medicine ◽  
Gradient Elution ◽  
Chemical Components ◽  
Isolation And Characterization ◽  
Major Chemical ◽  
Main Components ◽  
First Time

Background: Gentianella acuta (Michx.) Hulten is an important type of medicinal plant found in several Chinese provinces. It has been widely used in folk medicine to treat various illnesses. However, there is not enough detailed information about the chemical constituents of this plant or methods for their content determination. Objective: The focus of this work is the isolation and characterization of the major chemical constituents of Gentianella acuta, and developing an analytical method for their determination. Methods: The components of Gentianella acuta were isolated using (1) ethanol extraction and adsorption on macroporous resin. (2) and ethyl acetate extraction and high speed countercurrent chromatography. A HPLC-DAD method was developed using a C18 column and water-acetonitrile as the mobile phase. Based on compound polarities, both isocratic and gradient elution methods were developed. Results: A total of 29 compounds were isolated from this plant, of which 17 compounds were isolated from this genus for the first time. The main components in this plant were found to be xanthones. The HPLC-DAD method was developed and validated for their determination, and found to show good sensitivity and reliability. Conclusion: The results of this work add to the limited body of work available on this important medicinal plant. The findings will be useful for further investigation and development of Gentianella acuta for its valuable medicinal properties.

scholarly journals Urban Groundwater Contamination by Non-Steroidal Anti-Inflammatory Drugs

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 720
Author(s):  
Anna Jurado ◽  
Enric Vázquez-Suñé ◽  
Estanislao Pujades
Keyword(s):  
Salicylic Acid ◽  
Human Health ◽  
River Water ◽  
Human Health Risk ◽  
Urban Groundwater ◽  
Pollution Source ◽  
Groundwater Samples ◽  
Water Recharge ◽  
Inflammatory Drugs ◽  
Anti Inflammatory

Pharmaceuticals, such as non-steroidal anti-inflammatory drugs (NSAIDs) and their metabolites, have become a major concern due to their increasing consumption and their widespread occurrence in the environment. In this paper, we investigate the occurrence of NSAIDs and their metabolites in an urban aquifer, which may serve as a potential resource for drinking water, and propose a methodology to assess the removal of these substances in the river–groundwater interface. Then, risk quotients (RQs) are computed, in order to determine the risk posed by the single NSAIDs and their mixture to human health. To this end, six NSAIDs and two metabolites were collected from an urban aquifer located in the metropolitan area of Barcelona (NE, Spain), in which the major pollution source is a contaminated river. All of the target NSAIDs were detected in groundwater samples, where the concentrations in the aquifer were higher than those found in the river water (except for ibuprofen). Diclofenac, ketoprofen, propyphenazone and salicylic acid were detected at high mean concentrations (ranging from 91.8 ng/L to 225.2 ng/L) in the aquifer. In contrast, phenazone and mefenamic acid were found at low mean concentrations (i.e., lower than 25 ng/L) in the aquifer. According to the proposed approach, the mixing of river water recharge into the aquifer seemed to some extent to promote the removal of the NSAIDs under the sub-oxic to denitrifying conditions found in the groundwater. The NSAIDs that presented higher mean removal values were 4OH diclofenac (0.8), ibuprofen (0.78), salicylic acid (0.35) and diclofenac (0.28), which are likely to be naturally attenuated under the aforementioned redox conditions. Concerning human health risk assessment, the NSAIDs detected in groundwater and their mixture do not pose any risk for all age intervals considered, as the associated RQs were all less than 0.05. Nevertheless, this value must be taken with caution, as many pharmaceuticals might occur simultaneously in the groundwater.

scholarly journals Chemical Fingerprinting of Cryptic Species and Genetic Lineages of Aneura pinguis (L.) Dumort. (Marchantiophyta, Metzgeriidae)

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1180
Author(s):  
Rafał Wawrzyniak ◽  
Wiesław Wasiak ◽  
Beata Jasiewicz ◽  
Alina Bączkiewicz ◽  
Katarzyna Buczkowska
Keyword(s):  
Cluster Analysis ◽  
Cryptic Species ◽  
Plant Material ◽  
Chemical Constituents ◽  
Principal Component ◽  
Molecular Data ◽  
Rapid Identification ◽  
Multivariate Statistical ◽  
Genetic Lineages ◽  
Marker Compounds

Aneura pinguis (L.) Dumort. is a representative of the simple thalloid liverworts, one of the three main types of liverwort gametophytes. According to classical taxonomy, A. pinguis represents one morphologically variable species; however, genetic data reveal that this species is a complex consisting of 10 cryptic species (named by letters from A to J), of which four are further subdivided into two or three evolutionary lineages. The objective of this work was to develop an efficient method for the characterisation of plant material using marker compounds. The volatile chemical constituents of cryptic species within the liverwort A. pinguis were analysed by GC-MS. The compounds were isolated from plant material using the HS-SPME technique. Of the 66 compounds examined, 40 were identified. Of these 40 compounds, nine were selected for use as marker compounds of individual cryptic species of A. pinguis. A guide was then developed that clarified how these markers could be used for the rapid identification of the genetic lineages of A. pinguis. Multivariate statistical analyses (principal component and cluster analysis) revealed that the chemical compounds in A. pinguis made it possible to distinguish individual cryptic species (including genetic lineages), with the exception of cryptic species G and H. The classification of samples based on the volatile compounds by cluster analysis reflected phylogenetic relationships between cryptic species and genetic lineages of A. pinguis revealed based on molecular data.

The effect of training on the swimming muscles of the goldfish (Carassius auratus)

1978 ◽  
Vol 74 (1) ◽  
pp. 115-122 ◽  
Author(s):  
W. Davison ◽  
G. Goldspink
Keyword(s):  
Carassius Auratus ◽  
Chemical Constituents ◽  
Water Environment ◽  
Muscle Fibres ◽  
Muscle Fibre Size ◽  
Goldfish Carassius Auratus ◽  
High Speeds ◽  
Major Chemical ◽  
All Speeds ◽  
Rates Of Growth

Goldfish (Carassius auratus) were exercised continuously for periods of 28 days at swimming speeds of 1.5, 3.0 and 4.5 body lengths per second and their rates of growth were determined. Changes in muscle fibre size were examined, as were changes which occurred in the concentrations of the major chemical constituents of these cells. These fish, typical of the carp family in that they are found only in still or slowly moving water, did not adapt well to the flowing water environment at any swimming speed. They often grew less than the controls, although consuming much more food. Changes in the composition of the muscle fibres indicated that excess food was not being stored, and also indicated that the major fuel for swimming at all speeds was glycogen. The fish survived well at high speeds and it was suggested that this was due to the ability of the species to metabolize glycogen anaerobically without the production of lactic acid.

Geochemical modeling and multivariate statistical approach for assessing the groundwater quality, and mechanism of arsenic mobilization in Bahraich region, Indo-Gangetic plains, India

2021 ◽  
Author(s):  
Mohd Usman Khan ◽  
Nachiketa Rai ◽  
Mukesh Kumar Sharma
Keyword(s):  
Heavy Metal ◽  
Drinking Water ◽  
Heavy Metal Contamination ◽  
Geochemical Modeling ◽  
Sulfide Oxidation ◽  
Dissolution Mechanism ◽  
Multivariate Statistical ◽  
Gangetic Plains ◽  
Groundwater Samples

<p>As contamination in groundwater has been reported from various regions of the Indian subcontinent but no data related to heavy metal contamination of groundwater has been reported for the Bahraich area in the Indo-Gangetic plains. We report the first dataset on arsenic contamination and groundwater hydrogeochemistry, in Bahraich. This includes concentrations of heavy metal such as As, Mn, and Fe, along with major cations (Na<sup>+</sup>, K<sup>+</sup>, Ca<sup>2+</sup>and Mg<sup>2+</sup>) and anions (F<sup>-</sup>, Cl<sup>-</sup>, NO<sub>3</sub><sup>-</sup>, SO<sub>4</sub><sup>2-</sup> and PO<sub>4</sub><sup>3-</sup>), and dissolved organic carbon (DOC), along with various physico-chemical parameters such as EC, pH, and Eh from samples collected during two extensive field campaigns conducted during pre-monsoon, and post-monsoon seasons respectively. The combined use of geochemical modeling and multivariate statistical approaches such as principal component analysis (PCA) and correlation analysis (CA) suggest several processes affecting the geochemistry of groundwater including the lithological characteristics of aquifers and anthropogenic activities.</p><p>The groundwater of the study area predominantly belongs to the Ca-Mg-HCO<sub>3</sub> type hydrochemical facies. HCO<sub>3</sub><sup>−</sup>/Na<sup>+</sup> and Ca<sup>2+</sup>/Na<sup>+</sup> signatures of groundwater indicate the influence of silicate weathering and carbonate dissolution processes with the insignificant role of evaporate dissolution mechanism. As concentration was found to range from 0.6 μg/L to ~100 μg/L with almost 40% of the collected samples exceeding the WHO defined limit of 10 μg/L for drinking water. 70 % of the groundwater samples were found to have very high Fe concentrations exceeding the WHO guideline of 0.3 mg/l in drinking water. Mn concentrations in the groundwater samples were relatively low with only ~10 % of the samples exceeding the WHO defined limit for Mn (400 μg/L). The majority of the groundwater samples were found to be anoxic in nature showing low NO<sub>3</sub><sup>−</sup> & SO<sub>4</sub><sup>2-</sup> concentrations, high Fe & Mn and DOC concentrations, and negative Eh values.</p><p>Results from this study show that the reductive dissolution mechanism of iron oxyhydroxide is the dominant mechanism responsible for arsenic release in groundwater of the region, ruling out any role of sulfide oxidation and alkali desorption.</p><p> </p><p> </p>

scholarly journals Evaluating the Impacts of Agriculture to Groundwater Pollution in a Shallow Aquifer in Eastern Croatia

2011 ◽  
Vol 68 (2) ◽  
Author(s):  
Vilim FILIPOVIĆ ◽  
Dragutin PETOŠIĆ ◽  
Ivan ŠIMUNIĆ ◽  
Ivan MUSTAĆ ◽  
Zlatko SVEČNJAK ◽  
...  
Keyword(s):  
Groundwater Pollution ◽  
Agricultural Land ◽  
Shallow Aquifer ◽  
Nitrogen And Phosphorus ◽  
Potential Threat ◽  
Investigation Area ◽  
Groundwater Samples ◽  
The Mean ◽  
Phosphorus Levels ◽  
Observation Period

Agricultural activities are frequently associated with groundwater pollution. In this study, the goal is to evaluate the nitrate and phosphorus levels and it's impact to the groundwater. The investigation was located in the Eastern Croatia in the area of 6.600 ha of mainly agricultural land. Groundwater quality in the countertop part of the soil profile to 4.0 m depth was monitored by 40 installed hydropedological piezometers. Sampling water from piezometers was carried out every 60 days. In the groundwater samples nitrate, nitrite, ammonia and orthophosphate were analyzed. According to the indicators it was confirmed that at all locations during the observation period mean concentrations of NH4-N, NO3-N, total nitrogen (N) and phosphorus (P) in the groundwater from piezometers occasionally exceeded the value of maximum allowable concentration (MAC) which is prescribed by the Regulations. The mean concentrations of NO3-N were consistent and varied in the range from 2.42 to 4.61 mg NO3-N/l, the mean concentrations of nitrogen from ammonia exceed the permissible value (NH4-N) throughout the year, the average being higher than MAC (0.50 mg NH4-N/l) and were within the range of 0.57 mg NH4-N/l in to 1.21 mg NH4-N/l. The maximum concentration of phosphorus in groundwater were in the range of values from 0.40 to 1.11 mg P/l. Observation of traditional agricultural production in the investigation area with emphasis on leaching of nitrogen and phosphorus shows that it represents a potential threat to the future pollution of groundwater with nitrogen with phosphorus.

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