26 research outputs found
A comprehensive study to assess air quality degradation due to traffic and industrial pollution for Rawalpindi/Islamabad
No full textDocumentos apresentados no âmbito do reconhecimento de graus e diplomas estrangeiro
Investigating the Impact of Anthropogenic and Natural Sources of Pollution on Quality of Water in Upper Indus Basin (UIB) by Using Multivariate Statistical Analysis
No full textWater quality of the Indus River around the upper basin and the main river was evaluated with the help of statistical analysis. In order to analyze the similarities and dissimilarities for identifying the spatial variations in water quality of the Indus River and sources of contamination, multivariate statistical analysis, i.e., principle component analysis (PCA), cluster analysis, and descriptive analysis, was done. Data of 8 physicochemical quality parameters from 64 sampling stations belonging to 6 regions (labeled as M1, M2, M3, M4, M5, and M6) were used for analysis. The parameters used for assessing the water quality were pH, dissolved oxygen (DO), oxygen reducing potential (ORP), electrical conductivity (EC), total dissolved solids (TDS), salinity (%), and concentration of arsenic (As) and lead (Pb), respectively. PCA assisted in extracting and recognizing the responsible variation factors of water quality over the region, and the results showed three underlying factors including anthropogenic source pollution along with runoff due to rain and soil erosion were responsible for explaining the 93.87% of total variance. The parameters which were significantly influenced by anthropogenic impact are DO, EC, TDS (negative), and concentration of Pb (positive), while the concentration of As, % salinity, and ORP are affected by erosion and runoff due to rain. The worst pollution situation for regions M1 and M6 was due to the concentration of As which was approximately 400 μg/l (i.e., 40 times higher than minimum WHO recommendation). Furthermore, the results also indicated that, in the Indus River, three monitoring stations and five quality parameters are sufficient to have a reasonable confidence about the quality of water in this most important reserve of Pakistan
The Slaughter House Waste Management
No full textThousands of animals are slaughtered every year in Pakistan, but unfortunately there is no proper mecha-nism nor waste water management system to handle the effuent discharge of the slaughtering process. Therefore, this study was designed to evaluate the potential hazards associated with slaughter houses, by analyzing waste-water characteristics and designing a suitable treatment system for safe effuent disposal. The results obtained indicate that the wastewater parameters of the slaughter house do not meet the requirements of the local effuent dis-charge standards. The average wastewater characteristics in terms of COD, BOD, TDS, TSS, turbidity and pH observed were 9600mg/L, 7450 mg/L, 1650 mg/L, 2280 mg/L, 1489 NTU and 6.5, respectively. The results of plain sedimenta-tion point out that the maximum removal effciency of COD, BOD, TDS, TSS and turbidity at 80 minutes of detention time could be obtained as13%, 21%, 10%, 30% and 39%, respectively. Out of the three coagulants tested, the alum was tested out as the most suitable coagulant in terms of its treatability performance, which gives 80% COD removal compare to lime and magnesium sulfate that gives about 56% and 71% removal, respectively. The activated system designed consists of 12m x 7.5m x 3.5m rectangular aeration tank and 12m x 7m x 5m secondary sedimentation tank. The amount of air, power and the major nutrient (N and P) required for this system were worked out as 136m3/min, 7.8kW, 152 N-kg/day and 30 P-kg/day, respectively.Key words: Slaughter house effluent; Sedimentation; Alum; Activated sludge system; PakistanDOI: 10.3126/hn.v7i0.4236Hydro Nepal Journal of Water, Energy and Environment Vol 7, July, 2010Page: 48-53Uploaded date: 31 January, 2011</jats:p
Water Quality Assessment of Effluent Receiving Streams in Pakistan: A Case Study of Ravi River
No full textInfluence of Pier Modification Techniques for Reducing Scour around Bridge Piers
No full textBridge piers often fail all over the world and the whole structure may be endangered due to scouring phenomena. Scouring has been linked to catastrophic failures that lead into the loss of human lives. Various techniques have been employed to extenuate the scouring process in order to assist the bridge designs. Pier modifications plays vital role to control scouring at the vicinity of the pier. This experimental study aims at monitoring the effectiveness of pier modification and temporal development of scour depth around a bridge pier by providing a collar, a cable or openings under the same flow conditions. Provision of a collar around the octagonal pier reduced more scour depth than that for other two configurations. Providing a collar around the octagonal pier found to be the best in reducing scour. The scour depth in front of pier was found to be 19.5% less than that at the octagonal pier without any modifications. Similarly, the scour depth around the octagonal pier having provision of a cable was less than that at pier with provision of openings. The scour depth around an octagonal pier was also compared with a plain circular pier and found to be 9.1% less
Performance Assessment of Subsurface Drip Irrigation System Using Pipes of Varying Flexibility
No full textSubsurface drip irrigation method may play a significant role in overcoming the shortage
of water particularly in arid regions. An experimental investigation was carried out to
examine the efficiency of varying flexibility pipes installed in subsurface drip irrigation
system. The study was also aimed to investigate the effect of subsurface drip irrigation
on water requirement and yield of date palms. The testing was undertaken at Al-
Qassim, Saudi Arabia.
A considerable effect of pipe stiffness was observed on water consumption and yield. It
was found that the quantity of irrigation water reduced to 49-53% for drip pipes with
low flexibility as compared to that for medium and high flexibility pipes respectively.
The yield of date palms also increased and it was found 45-49% more than that for the
other two types
Experimental and numerical investigations for optimal emitter spacing in drip irrigation
No full textTHREE DIMENSIONAL CFD MODELLING OF FLOW STRUCTURE IN COMPOUND CHANNELS
No full textThe computational modeling of three dimensional flows in a meandering compound channel has been performed in this research work. The flow calculations are performed by solving 3D steady state continuity and Reynolds averaged Navier-Stokes equations. The turbulence closure is approximated with standard - turbulence model. The model equations are solved numerically with a general purpose software package. A comprehensive validation of the simulated results against the experimental data and a demonstration that the software used in this study has matured enough for investigating practical engineering problems are the major contributions of this paper. The model was initially validated. This was achieved by computing streamwise point velocities at different depths of various sections and depth averaged velocities at three cross sections along the main channel and comparing these results with experimental data. After the validation of the model, predictions were made for different flow parameters including velocity contours at the surface, pressure distribution, turbulence intensity etc. The results gave an overall understanding of these flow variables in meandering channels. The simulation also established the good prediction capability of the standard - turbulence model for flows in compound channels
Impact of Environmental Changes and Global Warming on Temperature in Pakistan
No full textEnvironmental changes and global warming have direct impact on human life. Estimation
of these changes in various parameters of hydrologic cycle is necessary for future
planning and development of a country. In this paper the impact of environmental
changes and global warming on temperatures of Pakistan has been studied. The
temperature changes in Pakistan have been extracted from simulations made using
EdGCM model developed at Columbia University. Simulation study to the end of 21st
century is executed using the model for GHG (Greenhouse Gases) scenario with
doubled_CO2 and scenario of Modern_Predicted SST (Sea Surface Temperature). The
model analysis has been carried out for seasonal and annual changes for an average of
last 5 years period from 2096-2100. Maps are generated to depict global temperature
variations. The study divides Pakistan into five (05) main areas for twenty six (26)
stations. A part-plan of globe focusing Pakistan is generated showing the five divisions
for twenty six (26) data stations of Pakistan. This part plan is made compatible with
grid-box resolution of EdGCM. Eagle-Point Engineering software has been used to
generate isohyets of interval (0.5oC) for downscaling GCM (Global Climate Model)
grid data to data stations.
The station values of different seasons and annual changes are then compared with the
values of base period data to determine changes in temperature. It is observed that
impact of global environmental changes on temperature are higher (i.e. there is an
increase in annual temperature for double_CO2 experiment) at places near the Arabian
Sea than areas located away from this sea. It is also observed that the temperature
increase will be more in winter than that in other seasons for Pakistan
Performance Evaluation of Aquatic Macrophytes for Municipal Wastewater Treatment
No full textMunicipal Sewage of Taxila was selected for evaluation and comparison of the performance of three aquatic macrophytes regarding sewage treatment. A bench scale laboratory model was developed and used for experimentation. Six experimental runs were conducted and each run laps over thirty (30) days. In each experimental run continuous monitoring of municipal sewage was done for each macrophyte specie. The aquatic macrophyte species used for the performance comparison were Water Hyacinth, Duckweed & Water Lettuce. For performance comparison four parameters including BOD5, COD, Nitrogen and Phosphorus were selected. These parameters were monitored for both the influent and effluent sewage samples. During the entire study, the average reduction of 51% for BOD5, 47% for COD, 19% for phosphorus, and 41% for nitrogen were found with water hyacinth. When the same sewage was treated with Duckweed the values came out to be 34% for BOD5, 27% for COD, 16% for phosphorus and 18% for nitrogen. Similar trend was observed in the experiments with Water Lettuce as 33 % for BOD5, 29% for COD, 11% for phosphorus and 15% for nitrogen. Sewage treatment in macrophyte based system included both the anaerobic & aerobic microbial processes. The treatment is further followed by chemical conversions, sedimentation & volatilization. The highest pollutant removals were observed for at temperature range of 15-38 oC and at pH variation between 6 and 9. In developing countries like Pakistan, where no importance is being given to municipal sewage treatment, the method found to be environmentally and financially sustainable. 
