ABSTRACT
The study investigated the potential of sand and activated charcoal filtration systems to enhance water quality for irrigation by treating aerated sewage effluent from. Setup involved a 60 cm deep sand filter connected as the inlet to another 30 cm deep sand filter and this filter linked as the inlet to a 30 cm deep charcoal filter. These filters were operated in series at hydraulic loading rates (HLR) of 60 m/h and 10 m/h. Notably, operating the filters in series at an HLR of 10 m/h yielded superior effluent water quality compared to an HLR of 60 m/h. System achieved significant removal efficiencies for turbidity, BOD5, COD, Total Nitrogen (Total-N), Total Phosphorous (Total-P) with 71.9%, 54.4%, 71.9%, 44.4%, 39.1%, and 42.9% with a 90 cm deep sand filter at an HLR of 10 m/h, and also with a combination of sand and charcoal filters at an HLR of 25 m/h system achieved 81.6%, 80.3%, 63.5%, 47.5%, and 64.3% respectively. We also examined the chemical characteristics of both untreated and treated sewage water samples, revealing a hierarchy of cation and anion prevalence as follows: Na+ > Ca2+ > Mg2+ > K+ for cations, and Cl- > HCO3- > SO42- > CO32- for anions. Our study demonstrates that the combination of aeration and sand filtration effectively ensures safety by preventing water body pollution and unpleasant odours with high-quality treated wastewater suitable for sustainable agricultural use.
ABSTRACT
Accurate assessment of water balance components holds paramount importance for the sustainable management of water resources in river basins. This study specifically concentrates on the application of the Soil and Water Assessment Tool (SWAT) model to evaluate water balance elements within the Noyyal River basin, a tributary of the Kaveri River originating from the Vellingiri hills in Western Tamil Nadu grapples with escalating water stress brought about by both anthropogenic activities and climatic fluctuations.The methodology adopted encompasses the harmonious integration of diverse spatial and temporal datasets. These datasets are seamlessly incorporated within the confines of a Geographic Information System (GIS) framework. Through the process of watershed delineation 21 sub-basin was partitioned and which is further subdivided into 217 unique Hydrological Response Units (HRUs) are derived, each corresponding to a distinct hydrological reaction. The simulation employs 33 years of daily precipitation, coupled with minimum and maximum temperature records, enabling the continuous execution of the SWAT model for runoff prediction. The findings elucidate fluctuating runoff volumes over time, spanning from a minimum of 11.17 mm to a maximum of 610.32 mm. Notably, the annual average runoff stands at 206.7 mm, representing approximately 25.6% of the cumulative rainfall experienced within the Noyyal river basin.
ABSTRACT
Corrosive injuries are common in developing countries. Acid ingestion is more common in developing countries when compared to alkali ingestion in developed countries. Ingestion may be accidental or suicidal. The nature of the corrosive ingested determines the extent of injury caused. Acidic injury commonly affects stomach than alkalis and it ranges from acute to chronic gastric injuries. In this article we discuss about the management of corrosive stricture of pylorus of stomach which was dealt by laparoscopy.
ABSTRACT
OBJECTIVE: Aim of our study was to evaluate the diagnostic accuracy of 64-slice CT coronary angiogram in measuring the percentage diameter stenosis compared to invasive angiography. METHODS AND RESULTS: 100 consecutive patients with more than 50% stenosis in at least one major coronary artery measured by 64-slice CT angiogram were included in the study. Patients with atrial fibrillation, history of allergy to contrast agent, acute coronary syndrome, renal insufficiency, history of previous coronary bypass surgery or percutaneous transluminal coronary stent, heart rate more than 70 per minute at the time of scan in spite of beta-blocker therapy, and calcium score >2000 Agaston units were not included in the study. 15-segment American Heart Association classification was used, and segments were compared using qualitative angiography. 192 segments (12.80%) could not be assessed due to poor image quality. The major cause for poor image quality was dense calcification precluding the luminal assessment (60.42%). Comparing the maximal percentage diameter stenosis by 64-slice CT versus invasive angiogram, the Spearman correlation coefficient between the two modalities was 0.788 and p value was <0.001. Bland-Altman analysis showed a mean difference in percentage stenosis of 2.1 +/- 16.22%. A total of 91.97% (401 of 436) of segments were within 1.96 standard deviations. CONCLUSION: This study shows that 64-slice CT coronary angiogram is accurate in detecting percentage diameter stenosis compared to coronary angiogram if the image quality is good. Calcifications and motion artifacts are the main culprits of poor image quality.