Cryptosporidium Oocysts in Drinking Water Supply of Chennai City,Southern India

Cryptosporidium is an enteric parasitic protozoan capable of causing chronic diarrhea. One of the most common modes of transmission is through faeces‐contaminated water. This study determines the distribution of Cryptosporidium oocysts for the first time in Chennai City's drinking water supply. 199 drinking water samples were collected from ten zones of the city. In the water samples Cryptosporidium, a common pathogenic protozoan of the gastrointestinal tract, has been analyzed physico chemically as well as microbiologically for heterotrophic organisms and total coliforms (TC). The studies revealed that three zones of the city were highly contaminated with coliforms and parasitic protozoa. A statistical analysis was done to find any correlation between heterotrophic organisms, total coliforms, and oocysts. Even though a positive correlation exists between oocysts and bacteriological parameters, a regression equation shows that heterotrophic plate count (HPC) and total coliforms were only 20% responsible for the presence of oocysts. The level of Cryptosporidium oocysts isolated from the water samples may present a public health hazard although no major outbreaks have so far been reported in Chennai City. Routine surveillance of water quality throughout the city is needed to curb the pollutants.     

Geotechnical characterization and analysis of rainfall—induced 2009 landslide at Marappalam area of Nilgiris district,Tamil Nadu state,India

Landslides are frequently occurring natural hazards in Nilgiris district of Tamil Nadu, India, particularly during monsoon season. The present study describes the geotechnical characterization and analysis of rainfall-induced landslide that occurred at Marappalam location of Nilgiris district on November 10, 2009. The detailed investigation comprises mapping of landslide, topographical survey, field and laboratory investigations, characterization of soil and rock, and numerical analysis. Field study comprises borehole and geophysical investigations. Detailed laboratory investigation was performed to identify index and engineering properties of soil and rock. Based on the results obtained from field and laboratory investigations, the generalized subsoil profile of Marappalam slope has been plotted. The investigations revealed that loose and soft soil layer with low permeability and plasticity interspersed with boulders could be the main source of debris flow. Scanning electron microscopic analysis and x-ray diffraction analysis were performed to study the influence of weathering on slope failure. Failure mechanism of Marappalam 2009 landslide was identified from the numerical analysis performed using landslide simulation program LS-RAPID. The analysis revealed that the 5-day antecedent rainfall (303 mm) and intense rainfall on 10th November 2009 (405 mm) saturate the slope due to infiltration of rainwater. This leads to a decrease in the matric suction and subsequent development of positive pore water pressure, which in turn reduces the shear resistance of the soil along with shear displacement, and resulted in a progressive failure.     

Hydrogeochemistry and microbial contamination of groundwater from Lower Ponnaiyar Basin, Cuddalore District, Tamil Nadu, India

Groundwater is the major source of fresh water in regions where there is inadequate surface water resources. Forty-seven groundwater samples were collected from Lower Ponnaiyar basin, Cuddalore District, south India, during the premonsoon (PRM) and postmonsoon (POM) seasons of 2005. Out of 47 groundwater samples, 15 samples showing higher nitrate concentration were those collected during PRM 2005. Microbial analysis of these samples was carried out by employing 16S rRNA gene sequence tool. Detailed analysis was conducted to determine the hydrogeochemical processes and microbial contamination responsible for deterioration of quality. The abundance of the ions during PRM and POM are in the following order: Na?>?Ca?>?Mg?>?K?=?Cl?>?HCO₃?>?SO₄?>?CO₃. The dominant water types in PRM are in the order of NaCl?>?CaMgCl?>?mixed CaNaHCO₃, whereas during POM NaCl?>?CaMgCl?>?mixed CaNaHCO₃, and CaHCO₃. However, NaCl and CaMgCl are major water types in the study area. The quality of groundwater in the study area is mainly impaired by surface contamination sources, mineral dissolution, ion exchange and evaporation. Groundwater chemistry was used to assess quality to ensure its suitability for drinking and irrigation, based on BIS and WHO standards. Suitability for irrigation was determined on the basis of the diagram of US Salinity Laboratory (USSL), sodium absorption ratio (SAR), residual sodium carbonate (RSC), and Na%. According to SAR and USSL classification, 27.66% (PRM) and 40.43% (POM) of samples fall under C3S2 category, indicating high salinity and medium sodium hazard, which restrict its suitability for irrigation. Microbiological analysis and its effects on the water quality were also addressed. The 16S rRNA gene sequences of 11 bacterial contaminants exhibited five groups with 11 operational taxonomic units with aerobic and facultatively anaerobic organisms. The presence of aerobic organisms in the groundwater samples reflects the active conversion of ammonia to nitrite by Nitrosomonas sp. which is further converted to nitrates by other organisms. Further the presence of nitrate reducers could also play a role in the process of conversion of nitrate to ammonia and nitrate to molecular nitrogen.     

Delineation of potential zones for artificial recharge using gis

In the present study, potential zones for artificial recharge in Agniar-Ambuliar-Southvellar river basins in Tamilnadu, India have been delineated through integration of various thematic maps using Arc view GIS. The study area, covers an area of 4566 km². Thematic maps pertaining to geology, permeability, effective soil depth, drainage intensity, soil texture, water holding capacity and physiography were prepared on 1:2,50,000 scale using conventional methods. These maps were scanned and registered with reference to a base map and are prepared as separate layers or coverages using Arc view. GIS has been used for the integration of various thematic maps to delineate the potential zones for artificial recharge. Each theme was assigned a weightage depending on its influence on groundwater recharge. Each class or unit in the map was assigned a knowledge based ranking from one to four depending on its significance in storage and transmittance of groundwater. The final map has been prepared showing four different categories of potential zones for artificial recharge.     

Modelling the impact of a subsurface barrier on groundwater flow in the lower Palar River basin, southern India

Groundwater modelling is widely used as a management tool to understand the behaviour of aquifer systems under different hydrological stresses, whether induced naturally or by humans. The objective of this study was to assess the effect of a subsurface barrier on groundwater flow in the Palar River basin, Tamil Nadu, southern India. Groundwater is supplied to a nearby nuclear power plant and groundwater also supplies irrigation, industrial and domestic needs. In order to meet the increasing demand for groundwater for the nuclear power station, a subsurface barrier/dam was proposed across Palar River to increase the groundwater heads and to minimise the subsurface discharge of groundwater into the sea. The groundwater model used in this study predicted that groundwater levels would increase by about 0.1?C0.3?m extending out a distance of about 1.5?C2?km from the upstream side of the barrier, while on the downstream side, the groundwater head would lower by about 0.1?C0.2?m. The model also predicted that with the subsurface barrier in place the additional groundwater requirement of approximately 13,600?m³/day (3 million gallons (UK)/day) can be met with minimum decline in regional groundwater head.     

Parameter Optimization of Activated Carbon Production from Agave sisalana and Punica granatum Peel: Adsorbents for C.I. Reactive Orange 4 Removal from Aqueous Solution

In the present study, activated carbons were prepared from sisal fiber (Agave sisalana sp.) and pomegranate peel (Punica granatum sp.) using phosphoric acid as the activating agent. Both sisal fiber activated carbon (SFAC) and pomegranate peel activated carbon (PPAC) were characterized using methylene blue number, iodine number, BET surface area, SEM, and FTIR. The BET surface area of the SFAC and PPAC were 885 and 686 m²/g, respectively. The adsorption studies using C.I. Reactive Orange 4 dye on the SFAC and PPAC were carried out. The effects of time, initial adsorbate concentration, pH, and temperature on the adsorption were studied. The isotherm studies were carried and it was found that the Langmuir and Freundlich isotherms fit well for the adsorption of RO 4 on SFAC, while adsorption of RO 4 on PPAC is better represented by the Langmuir and Temkin isotherms. Adsorption kinetics of adsorption was determined using pseudo first order, pseudo second order, Elovich and intraparticle diffusion models and it was found that the adsorption process follows pseudo second order model. Thermodynamics parameters such as changes in free energy (ΔG), enthalpy (ΔH), and entropy (ΔS) were determined by using van't Hoff equation. The positive ΔH value indicates that RO 4 dye adsorption on SFAC and PPAC is endothermic in nature.     

Solute transport modelling for assessing the duration of river flow to improve the groundwater quality in an intensively irrigated deltaic region

Groundwater modelling is an important management tool to study the behaviour of aquifer system under various hydrological stresses. Present study was carried out in deltaic regions of the Cauvery river, with an objective of estimating the minimum river flow required to improve the groundwater quality by numerical modelling. Cauvery river delta is the most productive agricultural plains of south India, but the agricultural activities during the last few decades have decreased due to limited flow in the river and increasing concentration of solutes in groundwater in the eastern parts. In order to understand the causes for increasing concentration, a three-layered finite-difference flow model was formulated to simulate the groundwater head and solute transport. The model was used to simulate the groundwater flow and solute transport for 5 years from July 2007 to June 2012. There was a fairly good agreement between the computed and observed groundwater heads. The chloride and nitrate ions were considered for solute transport modelling. Observed and simulated temporal variation in chloride and nitrate concentrations were comparable. The simulated solute concentrations from July 2007 to June 2012 showed an accumulation of solutes in groundwater of coastal part of the study area. The model was used to find the flow to be maintained in the river and rainfall recharge required to flush the ions into the sea. This can be achieved by maintaining minimal flow in the river and through regulation of fertilizer use as well as by creating awareness of sustainable use of groundwater in this area.     

Naphthalene Degradation Kinetics of Micrococcus sp., Isolated from Activated Sludge

Biodegradation of naphthalene by Micrococcus sp., isolated from the effluent of an activated sludge plant, was studied. The effects of pH (5–8), glucose concentration (100–1000 mg/L) and inoculum concentrations (1–5%) on the growth and naphthalene degradation potential of Micrococcus sp. were investigated. Maximum naphthalene degradation and subsequent high microbial growth were observed at optimum pH (pH 7), glucose concentration (500 mg/L) and inoculum concentration (3%). To investigate the maximum naphthalene tolerance potential of Micrococcus sp., very high concentrations of naphthalene (500–5000 mg/L) were used in the presence of non‐ionic surfactants. The examined surfactants (Triton X‐100 and Tween‐80) increased the bioavailability of naphthalene to the microbes and Complete naphthalene degradation by Micrococcus sp. was observed at an initial naphthalene concentration of 500 mg/L. However, the degradation potential decreases as the naphthalene concentration increases. Very high naphthalene concentrations also affected the growth of microbes and the corresponding substrate inhibition kinetics was described using four models (Haldane, Webb, Edward and Aiba). Based on correlation coefficient and percentage error values, all four substrate kinetic models were able to describe the dynamic behavior of naphthalene biodegradation by Micrococcus sp.     

Application of new RKAHeM(4,4) technique to analyze the structure of initial extrasolar giant protoplanets

Establishing and successfully implementing new numerical computational technique(s) with simulation tool is one of the most important difficult tasks in order to carry out real time scientific astronomical and other sophisticated problems. The main focus and highlight of this paper is concerned with the introduction of a newly proposed simple embedded RKAHeM(4,4) technique to determine the distribution of thermodynamic variables inside protoplanets during pre-collapse stage, formed by gravitational instability, for protoplanetary masses between 0.3 to 10 Jupiter masses. The case of convection is a significant concern for transference of heat inside the protoplanet and the graphical solution demonstrates positively better performance by inducting the newly proposed effective RKAHeM(4,4) algorithm for any length of time in comparison with the results through Classical Runge–Kutta method. Furthermore, the analytic expression for local truncation error, global truncation error and error estimates are derived for better understanding. A viable quantitative analysis has been carried out to clearly visualize the goodness and robustness of the proposed RKAHeM(4,4) algorithm.