Comparative analysis of bacterial contamination in tap and groundwater: A case study on water quality of Quetta City,an arid zone in Pakistan          下载免费PDF全文

Tanzeel Khan  Muhammad Akhtar Malik  Gohram Malghani  Rabia Akhtar 《地下水科学与工程》2022,10(2):153-165

Water is an essential element on earth, which provides human a variety of services in domestic use, agriculture, or industries. However, some serious health risks of drinking water are associated with microbial contamination, particularly with fecal matter. Therefore, microbial quality assessment is considered to be a necessary component of water quality assessment. This study investigates microbial contamination of water distributary system around the city by comparing groundwater (GW) and tap water (TW) quality in Quetta city. 31 GW samples and 31 TW samples were collected in the study area during the months of September, October, and November. Fecal coliform test was carried out in laboratory and their average total coliform contamination was computed. Results showed that the TW sample were all contaminated by coliform except for Chiltan town, hence are not considered suitable for drinking without any treatment according to WHO drinking water quality standards. The average coliform concentrations were 12 in Quetta main city, 11.6 in Jinnah town, 5.3 in Satallite town, 10 in Shahbaz town and 5 in Brewery town (0/100 mL CFU) and the TW samples from the three towns were even more contaminated with E.coli. Whereas among the GW, average microbial concentrations were 1.8 in Quetta main city, 2 in Satallite town, 1.4 in Shahbaz town, and 0.4 in Chiltan town (0/100 mL CFU), respectively, which shows that the contamination is occurring within the water distributary pipeline system when the water flows through the pipelines. Moreover, this research will be valuable for researchers and administrative authorities to conduct elaborative studies, and develop new policies to prevent further deterioration of drinking water in the water distribution system by pathogenic microorganisms and ensure safe drinking water to the public of Quetta city.  相似文献   

Boninitic geochemical characteristics of high-Mg mafic dykes from the Singhbhum Granitoid Complex,Eastern India     

Mir  Akhtar R.  Alvi  Shabber H.  Balaram  V. 《中国地球化学学报》2015,34(2):241-251

Acta Geochimica - The high-Mg mafic dykes from the Singhbhum Granitoid Complex in East India have geochemical characteristics [e.g., enrichment of the large ion lithophile elements and light rare...  相似文献   

Seismic fragility functions for code compliant and non-compliant RC SMRF structures in Pakistan     

Naveed Ahmad  Asif Shahzad  Qaisar Ali  Muhammad Rizwan  Akhtar Naeem Khan 《Bulletin of Earthquake Engineering》2018,16(10):4675-4703

Fragility functions are derived for low-rise code compliant & non-compliant special moment resisting frames (SMRFs). Non-compliant SMRFs those built in low strength concrete and lacking confining ties in joint panel zones, commonly found in developing countries. Shake table tests were performed on single-storey and two-storey 1:3 reduced scale representative frames to understand the damage mechanism and develop deformation-based damage scale. The non-compliant SMRF experienced column flexure cracking, longitudinal bar-slip in beam and observed with cover concrete spalling from the joint panels. The code compliant SMRF experienced flexure cracks in beam/column, and experienced joint cracking under extreme shaking. Numerical modeling technique is developed for inelastic modeling of reinforced concrete frame with beam bar-slip and joint damageability using SeismoStruct. Natural accelerograms were used to analyze the considered frames through incremental dynamic analyses in SeismoStruct. A probabilistic based approach was used to derive fragility functions for the considered frames. An example case study is presented for damageability evaluation of structures for earthquakes of various return periods (43, 72, 475, 2475 years).  相似文献   

Combining AHP and genetic algorithms approaches to modify DRASTIC model to assess groundwater vulnerability: a case study from Jianghan Plain,China     

Jing Yang  Zhonghua Tang  Tian Jiao  Akhtar Malik Muhammad 《Environmental Earth Sciences》2017,76(12):426

Accurate identification of vulnerability areas is critical for groundwater resources protection and management. The present study employed the modified DRASTIC model to assess the groundwater vulnerability of Jianghan Plain, a major farming area in central China. DRASTICL model was developed by incorporating the land use factor to the original model. The ratings and weightings of the selected parameters were optimized by analytic hierarchy process (AHP) method and genetic algorithms (GAs) method, respectively. A combined AHP–GAs method was proposed to further develop this methodology. The unity-based normalization process was employed to categorize the vulnerability maps into four types, such as very high (>0.75), high (0.5–0.75), low (0.25–0.5), and very low (<0.25). The accuracy of vulnerability mapping was validated by Pearson’s correlation coefficient between vulnerability index and the nitrate concentration in groundwater and analysis of variance F statistic. The results revealed that the modified DRASTIC model had a large improvement over the conventional model. The correlation coefficient increased significantly from 41.07 to 75.31% after modification. Sensitivity analysis indicated that the depth to groundwater with 39.28% of mean effective weight was the most critical factor affecting the groundwater vulnerability. The developed vulnerability model proposed in this study could provide important objective information for groundwater and environmental management at local level and innovation for international researchers.  相似文献   

Statistical landslide susceptibility assessment of the Mansehra and Torghar districts,Khyber Pakhtunkhwa Province,Pakistan     

Jewgenij Torizin  Michael Fuchs  Adnan Alam Awan  Ijaz Ahmad  Sardar Saeed Akhtar  Simon Sadiq  Asif Razzak  Daniel Weggenmann  Faseeh Fawad  Nimra Khalid  Faisan Sabir  Ahsan Jamal Khan 《Natural Hazards》2017,87(2):757-771

This paper presents laboratory experiments and numerical simulations of effects of submerged obstacles on tsunami-like solitary wave and its run-up. This study was carried out for the breaking and non-breaking solitary waves on 1:19.85 uniform slope which contains a submerged obstacle. New laboratory experiments are performed to describe the mitigation of tsunami amplitude and run-up under the effect of submerged obstacles. We are based on experimental results obtained to validate the numerical model. The numerical modeling using COULWAVE aims essentially to show the effect of the obstacle on the shape of solitary wave and the limit of this effect. Using a multiple nonlinear regression, we have determined a model to estimate height of run-up according to the amplitude of the wave and the obstacle peak depth.  相似文献   

The Impact of Geology of Recharge Areas on Groundwater Quality: A Case Study of Zhob River Basin,Pakistan   总被引：1，自引：0，他引：1  

Muhammad Umar  Amir Waseem  Muhammad Amjad Sabir  Akhtar Muhammad Kassi  Abdul Salam Khan 《洁净——土壤、空气、水》2013,41(2):119-127

Groundwater is a major source of water supply for domestic and irrigation uses in semiarid, remote but rapidly developing Kilasaifullah district part of Zhob River Basin, located at Pakistan–Afghanistan Border. Zhob River is among few major rivers of perennial nature in Balochistan, which flows from WSW to ENE and falls in Gomal River, a tributary of Indus River. Keeping in view the important geopolitical position and rapid development of the region, this study is primarily focused on groundwater chemistry for contamination sources as well as agriculture development. Water samples from open and tube wells are analyzed and calculated for electrical conductivity (EC), total dissolved solids (TDS), turbidity, pH, K⁺, Na⁺, Ca²⁺, Mg²⁺, HCO, Cl^?, NO, SO, PO, sodium percent (Na%), sodium adsorption ratio (SAR), Kelly's index (KI), and heavy metals (Fe, Cu, Cr, Zn, Pb, and Mn). On the basis of the chemical constituents two zones within the study area are identified and possible causes of the contaminants are pointed out. Two recharge areas were responsible for the different chemical results in groundwater, e.g., zone A was recharged from NNW saline geological formations (Nisai, Khojak, Multana, Bostan formations, and Muslim Bagh ophiolites), which are concentrated with high sodium and chloride. On the other hand Zone B was sourced from SSW from carbonate rich rocks (Alozai, Loralai, Parh formations, and Muslim Bagh ophiolites). The groundwater is classified as C2–S1, C3–S1, C3–S2, C4–S2 on the basis of EC and SAR values which indicate that most of the water of both zones can be used for irrigation safely except the samples plotted in C3–S2 and C4–S2 categories which could be dangerous for soil and crops. Groundwater samples are plotted in good to permissible limits with some samples excellent to good and few samples belong to doubtful category based on sodium percent. Groundwater of zone A is unsuitable for irrigation use due to higher values of KI (more than one) but water of zone B are good for irrigation based on KI. In general, water of both zones is suitable for irrigation but care should be taken during the selection of crops which are sensitive to alkalinity or sodium hazards particularly in zone A.  相似文献   

Estimation of the 3-D velocity structure of the Sorachi–Yezo and Oshima Belts in the western part of Hokkaido, Japan     

Ismail Husain Fathi  Kaoru Miyashita  Jun Kawahara 《Arabian Journal of Geosciences》2013,6(8):3111-3118

We adopted the seismic tomography technique to refine the three-dimensional velocity structure model of the western part of Hokkaido, Japan. Using the P-wave first arrival data listed by Japan Meteorological Agency from 2002 to 2005, we could estimate a 3-D inhomogeneous velocity structure model with a low velocity at a depth of 14 km beneath Asahikawa. The crustal structure near Sapporo was characterized by lateral velocity change toward the southern seaside. The low-velocity zone near Urakawa, proposed by previous research, was also clarified. In general, the present model showed lower-velocity values for most of the crustal layers in the area concerned. The results of this study were affected by less number of higher magnitude events (M?≥?0.5) in the central part of the area of interest. However, the perturbation results for comparatively shallow layers (6–50 km) were good in resolution. It was found that the source region of the Rumoi–Nanbu earthquake of December 14, 2004 was characterized by a low-velocity zone, located between high velocity zones. Such an inhomogeneous crustal structure might play an important role in the relatively high seismic activity in the Rumoi–Nanbu earthquake source region.  相似文献   

Natural Hazards in Bangladesh     

Afia Akhtar 《Gondwana Research》2001,4(4):561-562

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鄂尔多斯盆地上三叠统凝灰岩中的铀富集     

SHAMIM Akhtar  古黄玲  杨晓勇 《地质论评》2016,62(S1):403-404

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Novel preparation of sensitized ZnS nanoparticles and its use in photocatalytic degradation of tetracycline     

M. Ahadi  M. Saber Tehrani  P. Aberoomand Azar  S. Waqif Husain 《International Journal of Environmental Science and Technology》2016,13(12):2797-2804

Sensitized ZnS nanoparticles were synthesized by chemical precipitation method using anthocyanin as the capping agent and sensitizer. X-ray diffractometer, field-emission scanning electron microscope, transmission electron microscopy, UV visible spectrophotometer, Fourier transform infrared spectroscopy and photoluminescence spectrometry methods were used for the characterization of nanoparticles. The electron microscopy studies of nanoparticles showed that the size of crystallites is in the range of 35–80 nm and optical studies showed a blue shift in the absorption edge by adding capping agent. The effective band gap energy was increased with decrease in the particle size. Photocatalytic activities of sensitized ZnS and pure ZnS were evaluated by degradation of tetracycline in aqueous solution under visible light irradiation, and progress of the reaction was monitored spectrophotometrically. The different parameters affecting degradation such as the pH of solution, amount of semiconductor and reusability of catalyst for three cycles and the photocatalytic degradation kinetics of tetracycline were studied. More than 80% degradation was achieved within 5 h under visible light.  相似文献