Y. Anjaneyulu

Highly Sensitive and Selective Dynamic Light-Scattering Assay for TNT Detection Using p-ATP Attached Gold Nanoparticle

TNT is one of the most commonly used nitro aromatic explosives for landmines of military and terrorist activities. As a result, there is an urgent need for rapid and reliable methods for the detection of trace amount of TNT for screenings in airport, analysis of forensic samples, and environmental analysis. Driven by the need to detect trace amounts of TNT from environmental samples, this article demonstrates a label-free, highly selective, and ultrasensitive para-aminothiophenol (p-ATP) modified gold nanoparticle based dynamic light scattering (DLS) probe for TNT recognition in 100 pico molar (pM) level from ethanol:acetonitile mixture solution. Because of the formation of strong π-donor-acceptor interaction between TNT and p-ATP, para-aminothiophenol attached gold nanoparticles undergo aggregation in the presence of TNT, which changes the DLS intensity tremendously. A detailed mechanism for significant DLS intensity change has been discussed. Our experimental results show that TNT can be detected quickly and accurately without any dye tagging in 100 pM level with excellent discrimination against other nitro compounds.

Sonochemical degradation of 2chloro-5methyl phenol assisted by TiO2 and H2O2

The degradation of 2chloro-5methyl phenol (2C-5MP) in aqueous solution by ultrasonication (US) in the presence of TiO(2) and H(2)O(2) has been studied. Maximum degradation rate of 2.66 x 10(-2) was achieved by US/TiO(2)/H(2)O(2) process when compared to US/TiO(2) (1.01 x 10(-2)) and US/H(2)O(2) (5.5 x 10(-3)) systems. The effect of inorganic ions on degradation rate of 2C-5 MP were found to be in the order of Cl(-)>SO(4)(2-)>HPO(4)(2-)>HCO(3)(-). Further, the impact of synthetic additives like CCl(4) as hydrogen radical scavenger and CH(3)OH as hydroxyl radical scavenger on US were studied which confirmed the involvement of hydroxyl radicals in the degradation of 2C-5 MP. Kinetic studies revealed that the degradation process followed pseudo-first-order mechanism with the correlation coefficient (R(2)) of 0.9913 under experimental conditions.

Thermophilic degradation of phenolic compounds in lab scale hybrid up flow anaerobic sludge blanket reactors

This Study describes the feasibility of anaerobic degradation of United States Environmental Protection Agency (USEPA) listed 4-chloro-2-nitrophenol (4C-2-NP), 2-chloro-4-nitrophenol (2C-4-NP), 2-chloro-5-methylphenol (2C-5-MP) from a simulated wastewater using four identical 7L bench scale hybrid up flow anaerobic sludge blankets (HUASBs) at five different hydraulic retention times (HRTs) under thermophilic condition (55+/-3 degrees C). The substrate to co-substrate ratios were maintained between 1:33.3 and 1:166.6. Continuous monitoring of parameters like pH, volatile fatty acids (VFAs) accumulation, oxidation reduction potential, chemical oxygen demand (COD), alkalinity, gas productions, methane percentages were carried out along with compound reduction to asses the efficiency of biodegradation. The compound reduction was estimated by using spectrophotometric methods and further validated with high-performance liquid chromatography (HPLC). Optimum HRT values were observed at 24h. Optimum ratio of substrate (phenolic compounds) to co-substrate (glucose) was 1:100. Scanning electron micrographs show that the granules were composed of thermophilic Methanobrevibacter and thermophilic Methanothrix like bacteria.

Stabilization and solidification technologies for the remediation of contaminated soils and sediments - an overview

Many chemical aompdunds andmixfuras o f ~ u n d s , because 01 their widespread use, and in some hsfames. PeMBnt nature, have conthued to aacumulafe in SOB and sediments. T i aontamimnIs in bottom sedimenls 01 lakes create Ihepolential lor mtinued environmenfaldegmdalion. The process and techniques 01 stabilisalionl sdidilication (s/sJ of polluted soils and sedihave matured into an accepted and impdrtant pad d mmsdhtion technology. Thls paper gives an oven4ew at

Flame synthesis of carbon nano onions using liquefied petroleum gas without catalyst.

4 feohnob gies and Ihek mecIIanlsms. The apj)Ncation of each of these methodoIogies lo sustainable waslo mana@ment Is sunrmarised.

Photodegradation of Selected PCBs in the Presence of Nano-TiO2 as Catalyst and H2O2 as an Oxidant

Densely agglomerated, high specific surface area carbon nano onions with diameter of 30-40 nm have been synthesized. Liquefied petroleum gas and air mixtures produced carbon nano onions in diffusion flames without catalyst. The optimized oxidant to fuel ratio which produces carbon nano onions has been found to be 0.1 slpm/slpm. The experiment yielded 70% pure carbon nano onions with a rate of 5 g/h. X-ray diffraction, high-resolution electron microscopy and Raman spectrum reveal the densely packed sp(2) hybridized carbon with (002) semi-crystalline hexagonal graphite reflection. The carbon nano onions are thermally stable up to 600 °C.

Effects of Hurricane Katrina on Land Cover Within the Grand Bay National Estuarine Research Reserve in Mississippi, USA

Photodegradation of five strategically selected PCBs was carried out in acetonitrile/water 80:20. Quantum chemical calculations reveal that PCBs without any chlorine on ortho-positions are closer to be planar, while PCBs with at least one chlorine atoms at the ortho-positions causes the two benzene rings to be nearly perpendicular. Light-induced degradation of planar PCBs is much slower than the perpendicular ones. The use of nano-TiO2 speeds up the degradation of the planar PCBs, but slows down the degradation of the non-planar ones. The use of H2O2 speeds up the degradation of planar PCBs greatly (by >20 times), but has little effect on non-planar ones except 2,3,5,6-TCB. The relative photodegradation rate is: 2,2′,4,4′-TCB > 2,3,5,6-TCB > 2,6-DCB ≈ 3,3′,4,4′-TCB > 3,4′,5-TCB. The use of H2O2 in combination with sunlight irradiation could be an efficient and “green” technology for PCB remediation.

Model calculation of environmentally friendly traffic flows in a rapidly growing urban centre in India

Hurricane Katrina hit the Mississippi Gulf Coast on August 29, 2005 as a Category 3 hurricane at the mouth of the Pearl River, on the Mississippi/Louisiana border. Katrina is considered one of the costliest natural disasters in United States history. Grand Bay National Wildlife Refuge (GBNWR) is located in the coastal zone of Jackson County in Mississippi, and Mobile County in Alabama. The Mississippi portion of GBNWR is part of the 18,400-acre Grand Bay National Estuarine Research Reserve (NERR), which was designated in 1999. The objectives of this study were to map changes to wetland and forest habitats resulting from hurricane Katrina and to discuss the implications of changes in these habitats on biodiversity within the Grand Bay NERR. Pre- and post-Katrina subsets of the Grand Bay NERR were derived from Landsat images downloaded from The Coastal Change Analysis Program’s (C-CAP) website. Unsupervised classification and change detection analysis were applied to each Landsat-derived, 3-band datasets. The land cover change analysis revealed that hurricane Katrina caused a decrease in evergreen forest, and the conversion of evergreen forest into grassland. The major land cover changes were due to the expansion of open water. The increase in open water caused the decrease in estuarine emergent wetlands (salt marsh habitats) and the conversion of one type of land cover into another. These land cover changes could have a profound effect on the flora and fauna located within the reserve. Remote sensing technology appears to be a valuable tool for monitoring and implementing restoration and conservation strategies by the Grand Bay NERR managers.

Comparison of various advanced oxidation processes for the degradation of 4-chloro-2 nitrophenol

The paper highlights the application of an integrated decision support system for calculation of environmental friendly traffic flows in urban networks under different management strategies. Each proposed alternative is evaluated using a GIS and GPS environment that may, on a local basis, affect the environmental burden and contribute to pollution load in the region. For each link of the network an environmental capacity is calculated, taking into consideration the hydrodynamic theory based traffic flow dependent on the length of the road network and the average traffic volume and speed. The studied management options include: modifying the existing road network; road widening activities; bus bay relocation; construction of RUB/ROBs; rescheduling the work activities; parking management. The integrated transportation decision support system offers entirely new way of using the GIS, GPS and field survey data for model calculation of pollution load from road traffic to devise environmentally friendly traffic flows.