International Journal of Ground Sediment & Water

381

Authors: Sun Jichao

Editor Board © International Journal of Ground Sediment & Water, ©Sun Jichao. The website is https://ijgsw.eu.org/ http://ijgsw.net/

405-428

Authors: Adnan Khan*, Bisma Naz, Afrida Fatima, Meher Fatima, Ammara Dawood

Present study is carried out for the assessment of Halkani sandstone cropping out in the southwestern part of Karachi city. For this purpose, 20 rock samples were collected along Sona Pass area for geochemical and petrographic examination. Petrographic data revealed that the sand is mainly composed of quartz grains followed by feldspar and mica minerals in traces. Particle morphology revealed that mostly the sand is well sorted, sub rounded to angular where some grains show microfractures. Grain size analysis discovered that Halkani sand has 0.149 mm (100 mesh) size as modal class followed by 80 and 200 mesh. Chemical analysis revealed that silica content is about 86.2%. The mean concentration of Fe2O3 is 2.16% which is double the standard guidelines (< 1%). Conversely, mean concentration of Al2O3 is 2.96% which is within allowed limit of US standard (< 4%). Other major oxides including CaO (mean: 0.9%), MgO (0.44%), Na2O (0.3%) and K2O (0.32%) are within corresponding desired limits. Other trace elements (Cr2O3, ZnO, CoO, TiO2, CuO, BaO) varied between 0.03-0.2%. the mean wt% of B2O3 is 15.33% which is slightly above fiber glass requirement (10%). This sand is devoid of NiO, MnO and PbO (below detection level). These results indicate that Halkani sandstone is generally suitable for various types of glass. Further beneficiation can improve it for high grade glass manufacturing. © International Journal of Ground Sediment & Water, @ Sun Jichao. The website is https://ijgsw.eu.org/ http://ijgsw.net/

449-474

Authors: Adnan Khan, Ayesha Kanwal, Wasi Haider Zaidi

The main objective of present study is to evaluate the groundwater quality of Gulistan-e-Johar town for drinking purpose. Groundwater samples (n= 50) were collected from shallow boring wells at various depths (9-15m). The groundwater pH is acidic to basic (range: 6.7-7.8; mean: 7.2) where a large number of samples (80%) are alkaline. Geochemical data revealed that groundwater samples are highly saline (90%) where highly variable TDS content (range: 408-48192ppm; mean: 58192ppm) is reported. Major cation and anion varied in the order of Na (453 mg/l) >Ca (238 mg/l) >Mg (223mg/l) > K (29mg/l) and Cl (1435 mg/l) > SO4 (1086 mg/l) > HCO3 (318 mg/l) > NO3 (17 mg/l) respectively. Na and Ca have more than double the concentration of corresponding WHO guideline values. On the other hand, Mg content is four times higher than its recommended value. Elevated Fe content is also detected about one third in samples (0.1-0.67mg/l). About 60% of collected samples are sewage impacted as indicated by the occurrence of fecal coliforms. Principal component analysis explained five principal components (PCs). PC1 is suggesting rock water interaction and sewage mixing.PC2 shows prevalence ofanoxiaproperties.PC3 indicates strong Fe, Zn and turbidity relation which suggests ion exchange process.PC4 and PC5 have shown strong relation of nitrate with sewage indicating the prevalence of reducing environment. The study has concluded that intense geochemical processes and anthropogenic activities are altering the ground water quality of shallow aquifers in Gulistan-e-Johar area where high salinity and hardness are major menace. © International Journal of Ground Sediment & Water, @ Sun Jichao. The website is https://ijgsw.eu.org/ http://ijgsw.net/