Hydrochemical evaluation of river Ajali water for irrigational application in agricultural farmland

A major population of Udi and Ezeagu communities residing along river Ajali is peasant farmers who engage in the cultivation of vegetables along the river banks during the dry seasons. The existence of beverage industries around the 9th Mile Corner Ngwo of Enugu State has caused both communities to suffer from a shortage of quality drinking water, due to the constant discharge of wastewater by these industries into the Ajali River, which flows through these communities. Ajali River water near some beverage industries was then assessed for irrigation application. Water samples were collected from different locations along the river. Physicochemical and ionic parameters were analyzed using standard methods. Irrigation water criteria were applied, and the result showed that the major cation and anions were Mg2+, Ca2+, Na+, K+ and HCO3−, SO42−, $${\text{PO}}_{4}^{3- }$$ PO 4 3 - , NO3−, Cl−, CO3− . Na+ was dominant with 43% average contribution of all the cations, while the least was Mg2+ with 4% average contribution; HCO3− was the dominant anion with 31% contribution while $${\text{PO}}_{4}^{3- }$$ PO 4 3 - was the least with 2% average contribution. The trend of the cations was Na+ > K+ > Ca2+ > Mg2+ while the anions were HCO3− > SO42− > Cl− > NO3− > CO3− > PO43−. The cation concentrations were within FAO irrigation water specifications. However, some samples recorded higher values of carbonate above FAO limit (0–3 mg/L). All the irrigation assessment criteria suggested that Ajali River water is suitable for irrigation purposes.

Evolution of Ground Water Quality and Source Tracking of Nitrate Contamination in the Seymour Aquifer of Texas

Introduction: Nitrate contamination of groundwater in the Seymour Aquifer is a well-known issue that has been documented since the 1960's. Concentrations as high as 35 ppm NO3-N have been reported, which is a startling 3.5 times the EPA allowable standard for drinking water. While most water from the Seymour Aquifer is used for agricultural irrigation, a portion is still used for domestic purposes and therefore poses a risk to human health. While this problem has been recognized, the specific source of this contamination remains unknown. Research Approach: My research combined various analytical and geospatial technologies in order to 1) assess the evolution of groundwater in the Seymour Aquifer since before and after the 1960's, and 2) to determine the source of the high concentrations of nitrate in domestic wells situated on the aquifer. Readily available groundwater quality data from the Texas Water Development Board was used in conjunction with geospatial analysis and chemical analysis to identify changes in the aquifer's water quality over time. In addition to this data, fourteen well sites were sampled in the Spring and Fall of 2017 from selected domestic and irrigation wells situated atop the aquifer to provide an idea of present nitrate concentrations. Three potential sources of nitrate within the aquifer were considered in this study—the geological makeup of the aquifer, the contribution of nitrate from sewage and agricultural fertilizers, and the historical land use change of the area above the aquifer. Stiff diagrams are a graphical representation of major cation and anion concentrations within water samples. Well concentrations over the course of the past six decades of six major cation and anions typically present in groundwater were averaged and graphed to determine which ion closely matched the metamorphosis of the high levels of nitrate in this portion of the Seymour Formation. This allows one to safely assume that nitrate will behave similarly to that of chloride, and chloride can be used to predict the behavior of nitrate where nitrate data is scant. Spatial Analysis: An Empirical Bayesian kriging (EBK) analysis was performed via ArcMap in order to interpolate unknown values of Cl-and NO3- throughout the aquifer per known concentrations of well sites in order to map and trace the development of these two ions before 1960 (pre-heavy fertilizer use) and after. *Note: It is supposed, but not confirmed, that chloride concentrations may have dropped significantly due to the implementation of more efficient irrigation systems that decreased the flushing of salts from soils into groundwater. Geospatial analyst tools were utilized in order to predict the concentrations at the locations of the 14 sampled well sites for each of the mapped decades. The graph on the right plots the average forecasted outcomes of chloride and nitrate and indicates the correlation between these two ions in the aquifer. Isotope analysis: Elements found within chemical compounds exhibit certain stable isotopes, or an isotopic signature, that vary according to the source of the compound itself. The percentage of these unique isotopes within a given analyzed sample can be plotted against a known range of source values in order to determine the origin of the compound. Nitrogen and Oxygen in the compound nitrate (NO3-) have several known possible sources and nitrate contaminants in groundwater in particular could originate from decaying organic matter, soils, fertilizers, or sewage (or sometimes, a combination). Nine samples were taken at various wells across the Seymour Aquifer and were shipped to UC Davis for isotopic analysis. Conclusion: After mapping well site data provided by the TWDB, chloride and nitrate activity appear to be driven by the northern and southeastern portions of the aquifer. Thanks to isotopic and geostatistical analysis, it is valid to assume that the high concentrations of nitrate could possibly be driven both by the heavy agriculture of the area as well as by the mesquite tree roots left in the ground after the trees themselves were cleared for agriculture before the 1960’s. Mesquite contain deep reaching root systems that support nitrogen-fixing bacteria in its root nodules (and as a result, maintain pockets of nitrogen that extend deep into the earth). As indicated by map data, it is apparent that nitrate levels were still high even before the use of fertilizer in the area, lending support for this rationale. Of the nine samples collected for stable isotopic analysis, it was determined that all of the samples were sourced from either animal waste, soil, and/or septic waste. Additional study needs to be conducted in order to elaborate upon these findings. For example, isotopic data also indicated that sewage effluent is a contributing factor of nitrate, so further analysis into this discovery must be considered as well. Further research will also include increasing the sample size to provide a clearer view of present aquifer contamination, as well as conducting more detailed isotopic analysis methods to differentiate between origins of NO3-N as soil N and sewage N.

Groundwater Quality Evaluation for Irrigation and Drinking Utilities Collected from Sadar Upazila of Jamalpur District, Bangladesh

The study was undertaken to evaluate groundwater quality both for drinking and irrigation usage collected from the Sadar upazila of Jamalpur district, Bangladesh. Total 20 groundwater samples were collected from the whole area and analysed for various physicochemical parameters following standard protocols at the Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh during March to December 2017. Concentrations of different heavy metal (Fe, Mn, Cu, Pb, Cr, Cd and Zn) in groundwater samples were measured by an atomic absorption spectrophotometer (AAS). Major cation chemistry showed their dominance in order of Ca > Mg > Na > K. Among the anions, HCO3 was the most dominating ion, which makes all groundwater unsuitable for irrigation. But considering major cations and anions, all groundwater samples were rated as suitable for drinking. In context of heavy metals, the amounts of Mn, Cd and Pb in groundwater were comparatively higher than the standard limits, which makes 14, 8 and 19 samples problematic for irrigation, and 13, 18 and 1 samples unsuitable for drinking, respectively. Electrical conductivity (EC) and sodium adsorption ratio (SAR) reflected that all groundwater samples were low to medium salinity (C1-C2) and low alkalinity (S1) hazards classes. As regards to hardness, out of 20 groundwater samples, 9 samples were classified as moderately hard, 10 were hard and only 1 sample was very hard in quality. According to residual sodium carbonate (RSC), 18 groundwater samples were found in suitable class, 1 sample was rated as marginal and the rest 1 was categorised as unsuitable class. The study concluded that HCO3, Mn, Cd and Pb were the major contaminants in groundwater of Sadar upazila of Jamalpur district, Bangladesh. Finally, the study suggested that the groundwater in this area needs to treat to minimise the amount of contaminants before using both for irrigation and drinking.

The capsaicin receptor

The landmark paper discussed in this chapter is ‘The capsaicin receptor: A heat activated ion channel in the pain pathway’, published by Caterina et al. in 1997. The identification of the molecular basis for the sensitivity of a major proportion of nociceptive primary sensory neurons for capsaicin, the pungent agent in chilli pepper, was undoubtedly one of the most significant pain-related discoveries in the twentieth century, for at least three reasons. First, the mechanism for capsaicin-induced responses could unequivocally be explained. Second, the discovery heralded the starting point for the development of a highly promising, mechanism-based means of analgesia. Third, the discovery also sparked studies which resulted in the discovery of the major cation channel family, the transient receptor potential (TRP) ion channel family, several members of which have also become putative targets for the development of analgesics.

Hydrochemical properties of ground water of Rahaliya-Ekhedhur region, west Razzaza lake, iraq

Rahaliya - Ekhedur region is located to the west of Razzaza Lake (M.IRAQ). It is within the Salman - Rutba tectonic zones characterized by the existence of Abu Jir and Imam Ahmad bin Hashim Fault Systems. The major geological formations in the studied area consists of Tertiary and Quaternary deposits described from the oldest to the youngest as : Dammam, Euphrates, Nfayil and Injana, formations, and the slope of beds is less than one degree in the direction of east and northeast towards Al-Razzaza lake. To evaluate the hydrochemical properties and the quality groundwater samples were collected from 16 wells at different depths 80-120 m, during April and October 2013. These samples have been chemically analyzed and the results indicated that the ground water is of mixed origin, very hard (TH ranging from 227.5 to 1032.8 ppm), having high pH values, while the Total Dissolved Solids (TDS) ranging from 1700 to 2750 mg/l so that the water is of brackish type. On the basis of the major cation and anion concentration the groundwater during April 2013 was of mixed Mg and Na -SO4 group having two families which are Na2SO4 family with Na+>Ca2+>Mg2+-SO42- >Cl->HCO3- and MgSO4 water family with Mg2+>Ca2+>Na+-SO42- >Cl->HCO3-. While, the groundwater during October 2013 is of two groups (Na -SO4) having two families which are (Na2SO4) family with Na+>Ca2+>Mg2+-SO42- >Cl->HCO3-and (MgSO4) water family with Mg2+> Ca2+>Na+-SO42- >Cl->HCO3-. The second group was Na - Cl with Na+> Mg2+>Ca2+ - Cl->SO42- > HCO3- and Na+>Ca2+>Mg2+ - Cl->SO42- > HCO3- . Therefore, the ground water in the region is not good for drinking due to high salinity and it is of Doubtful to unsuitable-Unsuitable for irrigation but it can be used to irrigate sensitive crops in areas.

Study of Thermal Water Resources in Sri Lanka Using Time Domain Electromagnetics (TDEM)

Thermal springs can be utilized as an environmental friendly source of renewable energy, as well as for other purposes. Time domain electromagnetic (TDEM) method is used as an accessory tool in geothermal exploration to investigate the local heterogeneities in geology. The study consists of two of the thermal springs in Sri Lanka, Wahawa and Mahaoya, both in the same crustal unit. Major structural discontinuities of the area vary between two peculiar fracture sets striking ENE and NW. Close relationships between these individual springs have been witnessed by their approximate major cation chemistries, which provoke the idea of geochemical provinces. Survey reveals the pathways of the heated water to the surface, at Wahawa, although the path is not clear at Mahaoya. Near surface resistivity diagrams can be used only to interpret the immediate depths of the springs. The expected structural relationships may be identified with a grid of TDEM soundings encompassing both the spring systems.

Rock denudation rates and organic carbon exports along a latitudinal gradient in the Hudson, James, and Ungava bays watershed

This study documents chemical denudation rates (CDR) in the Canadian Shield and Interior Platform. It focuses on the dissolved chemistry of rivers flowing into the Hudson, James, and Ungava bays (HJUB). Major ions, strontium, neodymium, and dissolved organic carbon (DOC) concentrations were monitored in four rivers (Koksoak, Great Whale, La Grande, and Nelson). Six other rivers flowing into the HJUB were sampled during baseflow and snowmelt conditions. The rivers of the Canadian Shield exhibit major cation concentrations ranging between 62 and 360 µmol/L, [Nd] of 0.57–4.72 nmol/L, and variable [DOC] of 241–1777 µmol/L. In comparison, the Nelson River (Interior Platform) shows higher major cation concentrations (1200–2276 µmol/L), lower [Nd] (0.14–0.45 nmol/L), and intermediate [DOC] (753–928 µmol/L). Altogether, the studied rivers export 8 × 106 t/year of dissolved major cations and 50 t/year of dissolved Nd towards the HJUB. Basin-scale rock denudation rates (RDR) range from 1.0 to 5.3 t·km–2·year–1 and are essentially controlled by lithology, as illustrated by the relationship established between RDR and the proportion of sedimentary and volcanic rocks (%S + %V) within the basins: RDR = 0.08(%S + %V) + 0.9. In contrast, dissolved Nd exports (and likely other insoluble elements) seem to be dependent upon organic matter leaching, as illustrated by the empirical coupling between Nd and DOC exports. These fluxes decrease northwards, likely in response to the hydroclimatic gradient. The CDR evaluated within the Canadian Shield are among the lowest on the planet, and the alkalinity generated by rock weathering remains small with respect to DOC exports.