Chemical Property Variation Trend Analysis and Quality Evaluation of Water in Wei River

[Objective] Water quality variation trend of Wei River was analyzed and the water quality evaluation was performed in this study. [Method] Stationing and water sampling were conducted along Wei River at three different sites during the 12 months from January to December of 2014, the water samples were pre-treated and analyzed on chemical pollution indexes with the national standard, water quality data of Wei River in the 12 months was processed with periodic time series method, Spearman rank correlation coefficient was adopted to test pollution changing trend, and water quality status of Wei water was evaluated with integrated index of organic pollution. [Result] NH3-N and TN of Wei River exceeded the standard＇s lim- its; [ Y~ [ 〉Wp=0.506, [ Yss~ [ 〉Wp=0.506 and [ Y＆=0~,, Diecqieo 〉Wp=0.506 indicated that the integrated index of organic pollution of Shawangdu section, S.huyuan section and Tongguan Diaoqiao section showed a significant downtrend, respetively; and the water quality of the three sections became better, and it was worth noting that it was necessary to strengthen the water quality control of Wei River from January to June, so as to ensure that the water quality of Wei River reached the standard all the time. [Cendasien] This research was of significance in improving water ecological environment in Weinan as well as rationally utilizing water resources and finally realizing permanent development. Key words Wei River; Water quality variation trend; Integrated index of organic pollution; Evaluation

Hydrogeochemical Model and Water Quality of Groundwater in the Granito-Basaltic Fractured Rock Aquiferous Formations in Bafoussam, West Region-Cameroon

This study determined the hydrogeochemical model of groundwater and groundwater domestic-agro-industrial quality in Bafoussam using hydrogeochemical tools and physicochemical parameters: Ionic ratios, Gibbs diagrams, Piper diagrams, Durov diagrams and water quality indices. From physicochemical parameters;pH ranged from, 4.47 - 7.84;EC, 10 - 820 μS/cm;Temperature, 22.3°C - 29.5°C and TDS, 6.7 - 549.4 mg/L. The major ions fell below WHO acceptable limits. The sequences of major ionic abundance are: Ca2+ > Mg2+ > K+ > Na+ > NH+4, HCO-3 > Cl- > SO2-4 > NO3 > HPO2-4. Recharge by atmospheric precipitation, ion-exchange and simple dissolution processes are responsible for groundwater character, ionic content resulted from ion exchange and rock-weathering. Water types are Ca-HCO3 and Ca-Cl Hydrogeochemical facies are Ca-Mg-Cl-SO4 and Ca-Mg-HCO3. Domestic water quality was determined by use of pH, electrical Conductivity EC, total dissolved solids TDS, total Hardness HT and water quality index WQI. WQI values ranged from 0 - 42.09 and HT 67.89 - 339.01 indicating that water is of good domestic quality. Agro-industrial suitability of groundwater was determined using, sodium adsorption ratio SAR, permeability index PI, Magnesium adsorption ratio MAR, percent sodium %Na, Kelly’s ratio KR and Residual sodium carbonate RSC and Wilcox diagram;From irrigational water suitability parameters, SAR values ranged from 0.01 - 0 05;%Na 3.69 - 15.50;KR 0.005 - 0.023;PI 1.04 - 67.98;MAR 2.89 - 55.27;RSC -5.22 to -0.44 and Wilcox diagram indicate that inorganic groundwater content in the study area is excellent-good for irrigation;this is of significance since Bafoussam a major agroindustrial zone in Cameroon and Central Africa is in the process of developing large scaled irrigation based agricultural projects dependent on use of surface and groundwater. Recharge from precipitation exchanges ions with the weathered country rocks and mixes with regional flow in a generally south-east north-westerly direction by piston flow in the granito-basaltic aquiferous formations in Bafoussam. There is need for detailed studies to determine aquifer characteristics: permeability, transmissivity and storativity, vertical-lateral regional extent of aquifer boundaries, groundwater pollution potentials for biological, organic and trace metals.