Persistence and Dissipation Kinetics of Spiromesifen in Chili and Cotton

In a field study carried out at three different locations, the dissipation of spiromesifen on cotton and chili was studied and its DT₅₀, and DT₉₉ were estimated at each location. Spiromesifen was sprayed on chili at 96 and 192 g a.i. ha⁻¹ and cotton at 120 and 240 g a.i. ha⁻¹. Samples of chili fruits were drawn at 0, 1, 3, 5, 7, 10, 15, 21, 30 days after treatment and that of cotton seed and lint at first picking and harvest. Soil samples were drawn 30 days after treatment from 0 to 15 and 15 to 30 cm layer. Quantification of residues was done on GC–MS in Selected Ion Monitoring (SIM) mode in mass range 271–274 m/z. The LOQ of this method was found 0.033 μg g⁻¹, LOD being 0.01 μg g⁻¹. The DT₅₀ of spiromesifen when applied at recommended doses in chili fruits was found to be 2.18–2.40 days. Ninety-nine percent degradation was found to occur within 14.5–16.3 days after application. Residues of spiromesifen were not detected in cotton seed and lint samples at the first picking. In soil, no residues of spiromesifen were detectable 15 days after treatment.     

Characterization and cadmium-resistant gene expression of biofilm-forming marine bacterium Pseudomonas aeruginosa JP-11

Biofilm-forming marine bacterium Pseudomonas aeruginosa JP-11 was isolated from coastal marine sediment of Paradeep Port, Odisha, East Coast, India, which resisted up to 1,000 ppm of cadmium (Cd) as cadmium chloride in aerobic conditions with a minimal inhibitory concentration of 1,250 ppm. Biomass and extracellular polymeric substances (EPS) secreted by the cells effectively removed 58.760?±?10.62 and 29.544?±?8.02 % of Cd, respectively. The integrated density of the biofilm-EPS observed under fluorescence microscope changed significantly (P?≤?0.05) in the presence of 50, 250, 450, 650 and 850 ppm Cd. ATR-FTIR spectroscopy showed a peak at 2,365.09/cm in the presence of 50, 250, 450 and 650 ppm Cd which depicts the presence of sulphydryl group (–SH) within the EPS, whereas, a peak shift to 2,314.837/cm in the presence of 850 ppm Cd suggested the major role of this functional group in the binding with cadmium. On exposure to Cd at 100, 500 and 1,000 ppm, the expression profiles of cadmium resistance gene (czcABC) in the isolate showed an up-regulation of 3.52-, 17- and 24-fold, respectively. On the other hand, down-regulation was observed with variation in the optimum pH (6) and salinity (20 g l^?1) level. Thus, the cadmium resistance gene expression increases on Cd stress up to the tolerance level, but an optimum pH and salinity are the crucial factors for proper functioning of cadmium resistance gene.     

Post-tsunami changes in the littoral environment along the southeast coast of India

The 26th December 2004 Indian Ocean tsunami devastated coastal regions of the Indian subcontinent. Andaman and Nicobar Islands, coastal stretches of Tamil Nadu, Andhra Pradesh and Kerala were the most affected regions of India. Changes in the beach profiles, long shore currents, breaking wave characteristics in the surf zone at selected locations along the Tamil Nadu coast were studied during January, April, October 2005 and January 2006. Long shore sediment transport rates were estimated from the observed parameters. Studies were carried out earlier (1995-1996 and 1998) to understand the coastal environment over a one-year cycle in the study region. The post-tsunami observations were compared with the earlier studies to establish the variations in the littoral environment and to ascertain the normalcy of the littoral environment in the post-tsunami scenario. From the changes in the beach profiles, the shoreline was observed to recede by about 20m and built-up of backshore by about 0.5m at most locations. Observations from the field investigations and comparisons with earlier studies along this stretch of the coastline indicate that the coastline is yet to return completely to normalcy.     

Intensified wheat husk conversion employing energy-efficient hybrid electromagnetic radiations for production of fermentable sugar: process optimization and life cycle assessment

Environmental Science and Pollution Research - This article reports an energy-efficient green pathway for the sustainable conversion of an abundant agro-residue viz. wheat husk (WH) into...     

Life cycle assessment of waste printed wiring board–derived Ag photocatalyst for sustainable fermentable sugar production

Environmental Science and Pollution Research - An exploratory work involving waste printed wiring board (WPWB)–derived inexpensive silver oxide (Ag2O)–grafted silica-alumina composite...     

Impact of salinity and pH on phytoplankton communities in a tropical freshwater system: An investigation with pigment analysis by HPLC

An in vitro study was carried out to understand the effects of salinity shock and variation in pH on phytoplankton communities in a tropical freshwater system of the Godavari River (a major peninsular river in India). The distributions of, and variations in, phytoplankton communities were assessed by quantitative determination of their class specific marker pigments, using HPLC. Subtle changes in salinity of the freshwater by one practical salinity unit (PSU) completely removed green algae from the system and allowed the cyanobacteria to come into dominance. The cyanobacteria were found to tolerate higher osmotic stress until the salinity reached a PSU of 16. The higher salinity tolerance range of the cyanobacteria was attributed to the enhanced synthesis of zeaxanthin as protective xanthophylls against the osmotic stress. However, the effects of changing pH were not as dramatic as salinity where the green algae and the cyanobacteria from the same freshwater system showed a considerable acclimation towards the fluctuating pH. These findings are environmentally relevant to understand the likely impact of salt water intrusion and pH variation on phytoplankton communities in a tropical freshwater system.     

A comparative study of biopolymers and alum in the separation and recovery of pulp fibres from paper mill effluent by flocculation

Recovery of cellulose fibres from paper mill effluent has been studied using common polysacchatides or biopolymers such as Guar gum, Xanthan gum and Locust bean gum as flocculent. Guar gum is commonly used in sizing paper and routinely used in paper making. The results have been compared with the performance of alum, which is a common coagulant and a key ingredient of the paper industry. Guar gum recovered about 3.86 mg/L of fibre and was most effective among the biopolyrners. Settling velocity distribution curves demonstrated that Guar gum was able to settle the fibres faster than the other biopolymers; however, alum displayed the highest particle removal rate than all the biopolymers at any of the settling velocities. Alum, Guar gum, Xanthan gum and Locust bean gum removed 97.46%, 94.68%, 92.39% and 92.46% turbidity of raw effluent at a settling velocity of 0.5 cm/min, respectively. The conditions for obtaining the lowest sludge volume index such as pH, dose and mixing speed were optimised for guar gum which was the most effective among the biopolymers. Response surface methodology was used to design all experiments, and an optimum operational setting was proposed. The test results indicate similar performance of alum and Guar gum in terms of fioc settling velocities and sludge volume index. Since Guar gum is a plant derived natural substance, it is environmentally benign and offers a green treatment option to the paper mills for pulp recycling.     

Plant canopies: bio-monitor and trap for re-suspended dust particulates contaminated with heavy metals

Urban and peri-urban vegetation is being considered for air pollution abatement. Appropriate plants with efficiency to adsorb and absorb air-pollutants are the prerequisite for green space development. The contributions of surface morphology towards plant’s ability to function as dust particulate adsorber and distribution of trace elements over the leaves are investigated in the present study. Dust interception efficiency was estimated for two roadside plant species named Ficus benghalensis, and Polyalthia longifolia. Leaves of both the plants are capable of capturing dust in the range of 0.12 mg/cm² to 1.89 mg/cm² on either of the leaf surfaces. However, variation in dust capturing capacity between the plants was observed. Leaf surface characters such as roughness, length, frequency of trichomes and frequency of stomata played a significant role in capturing re-suspended dust. Frequency (2 to 4 per 0.0004 cm²) and length (152.5 to 92.1 cm) of trichome showed negative co-relation trend, where as frequency and size of stomata showed positive co-relation trend. Elemental analysis by Scanning Electron Microscope attached with Energy Dispersive X-Ray Spectrometer (SEMEDS) indicated the presence of elements such as Sodium (Na), Magnesium (Mg), Aluminium (Al), Silicon (Si), Chlorine (Cl), Pottasium (K), Calcium (Ca), Iron (Fe), Zinc (Zn) and Arsenic (As). The results support the fact that plant canopies can be used for mitigation and bio-monitoring of air pollution as well.     

Life cycle sustainability assessment of optimized biodiesel production from used rice bran oil employing waste derived-hydroxyapatite supported vanadium catalyst

Environmental Science and Pollution Research - The present work encompasses the production of biodiesel from an inexpensive waste, viz., used rice bran oil (URBO) through concurrent esterification...     

Chronic kidney disease of unknown etiology in India: a comparative study with Mesoamerican and Sri Lankan nephropathy

Environmental Science and Pollution Research - Chronic kidney disease of unknown etiology [CKDu] is a condition characterized by decline in kidney function and is not associated with diabetic...