Perchlorate contamination of groundwater from fireworks manufacturing area in South India

Perchlorate contamination was investigated in groundwater and surface water from Sivakasi and Madurai in the Tamil Nadu State of South India. Sensitive determination of perchlorate (LOQ?=?0.005 μg/L) was achieved by large-volume (500 μL) injection ion chromatography coupled with tandem mass spectrometry. Concentrations of perchlorate were <0.005–7,690 μg/L in groundwater (n?=?60), <0.005–30.2 μg/L in surface water (n?=?11), and 0.063–0.393 μg/L in tap water (n?=?3). Levels in groundwater were significantly higher in the fireworks factory area than in the other locations, indicating that the fireworks and safety match industries are principal sources of perchlorate pollution. This is the first study that reports the contamination status of perchlorate in this area and reveals firework manufacture to be the pollution source. Since perchlorate levels in 17 out of 57 groundwater samples from Sivakasi, and none from Madurai, exceeded the drinking water guideline level proposed by USEPA (15 μg/L), further investigation on human health is warranted.     

Correlating the trends of COVID-19 spread and air quality during lockdowns in Tier-I and Tier-II cities of India—lessons learnt and futuristic strategies

Environmental Science and Pollution Research - The present study focuses on the impact of early imposed lockdowns and following unlocking phases on the status of air quality in six Tier-I and nine...     

The influence of ceramic-coated piston crown,exhaust gas recirculation,compression ratio and engine load on the performance and emission behavior of kapok oil–diesel blend operated diesel engine in comparison with thermal analysis

In this work, the development and usability of kapok oil in diesel engine was intended. With this purpose, the piston crowns are coated with mullite–lanthanum (ML) ceramic composite at varying compositions in order to reduce the heat rejection during combustion process. The kapok oil is blended with diesel fuel consisting of (20% kapok oil–80% diesel) volumetrically named B fuel. The B and diesel (D) fuels are taken for the engine performance test with different coated piston (ML1, ML2, and ML3) and exhaust gas recirculation (EGR—10%, 20%, and 30%), compression ratio (CR—16, 17, and 18) and engine load (50%, 75%, and 100%). Also, the engine performance study on brake thermal efficiency (BTE), brake-specific fuel consumption (BSFC), hydrocarbons (HCs), oxides of nitrogen (NOx), carbon monoxide (CO), smoke opacity, and numerical study using ANSYS software is carried out. When operated with ML2-coated pistons with B fuel, maximum BTE value of 29.2%, minimum BSFC value of 0.224 kg/kW-h, CO emission of 0.2%, and smoke opacity of 39 ppm were observed. The results showed that ML2-coated piston considerably improved the performance of the test engines when compared with ML1 and ML3 coatings. Except for NOx emission, all other pollutant emission values were reduced. The numerical analysis using ANSYS software for ML2-coated pistons showed better retention of in-cylinder chamber temperature.

     

Biodegradable Poly(butylene succinate) and Poly(butylene adipate-co-terephthalate) Blends: Reactive Extrusion and Performance Evaluation

Two biodegradable polyesters, poly(butylene adipate-co-terephthalate) (PBAT) and poly(butylene succinate) (PBS) were melt-compounded in a twin screw extruder to fabricate a novel PBS/PBAT blend. The compatibility of the blend was attributed to the transesterification reaction that was confirmed by Fourier transform infrared spectroscopy. The Gibbs free energy equation was applied to explain the miscibility of the resulting blend. Dynamic mechanical analysis of the blends exhibits an intermediate tanδ peak compared to the individual components which suggests that the blend achieved compatibility. One of the key findings is that the tensile strength of the optimized blend is higher than each of the blended partner. Rheological properties revealed a strong shear-thinning tendency of the blend by the addition of PBAT into PBS. The phase morphology of the blends was observed through scanning electron microscopy, which revealed that phase separation occurred in the blends. The spherulite growth in the blends was highly influenced by the crystallization temperature and composition. In addition, the presence of a dispersed amorphous phase was found to be a hindrance to the spherulite growth, which was confirmed by polarizing optical microscopy. Furthermore, the increased crystallization ability of PBAT in the blend systems gives the blend a balanced thermal resistance property.     

Biosorption of Cu (II) ions by indigenous copper-resistant bacteria isolated from polluted coastal environment

The concentrations of copper in water and sediment samples of Cuddalore coastal area, Tamil Nadu, India were examined. The isolation, characterization, screening, and metal sorption capabilities of copper-resistant bacteria (CURB) also were investigated. Biosorption capabilities and growth time varied among the resistant isolates. All isolates reduced more than 80% of copper from copper-treated broth. However, Bacillus cereus CURB-4 strain absorbed more copper ions (99.9%) than other resistant isolates. Changes in structural group position and synthesis of extracellular polysaccharides (EPS) of CURB-4 strain under copper stress and controlled conditions also were examined. Under copper stress condition, CURB-4 produced more EPS (71 ± 0.6%) compared to control conditions (66 ± 0.4%). Fourier transform infrared spectroscopy revealed that the changes in functional group position of EPS were observed in stressed condition. Overall, synthesis of EPS in bacteria is a protective barrier against environmental stress.     

Three-phase partitioning for the separation of proteins,enzymes, biopolymers,oils and pigments: a review

Environmental Chemistry Letters - Modern biomass and organic waste are becoming major, carbon-neutral sources of fine chemicals, biomolecules and fuels to replace fossil fuel products. As a...     

Applications and genotoxicity of nanomaterials in the food industry

The use of nanomaterials in industrial sectors is currently widely accepted because of their unique beneficial properties. However, those unique properties can also induce toxic effects. Toxicity responses are induced by kinetic, dynamic, and catalytic properties, and by functionalization, net particle reactivity, agglomeration, and functional environment. Here, we review nanomaterial applications in food and consumer industries, genotoxic mechanisms, methods to study nanomaterials, and factors of toxicity.     

Non-steroidal anti-inflammatory drugs in Indian rivers

Pharmaceutical concentration data for Indian surface waters are currently scarce. Sewage often enters Indian rivers without prior treatment, and so previously reported environmental concentrations from regions with routinely implemented sewage treatment cannot simply be used to predict concentrations in Indian surface water. Improved knowledge of pharmaceutical concentrations in Indian waters would enable determination of potential risks posed to aquatic wildlife and human health in this region. The concentrations of five common non-steroidal anti-inflammatory drugs (NSAIDs; diclofenac, ketoprofen, naproxen, ibuprofen, and acetylsalicylic acid) were determined in surface waters from 27 locations of the Kaveri, Vellar, and Tamiraparani Rivers in southern India. The samples were extracted by solid-phase extraction and analyzed by GC-MS. The measured concentrations of four of the five drugs in this reconnaissance were relatively similar to those reported elsewhere (ND–200 ng/l); however, acetylsalicylic acid, the most readily degradable of the investigated drugs, was found at all sites and at considerably higher concentrations (up to 660 ng/l) than reported in European surface waters. This is the first report on the occurrence of NSAIDs in Indian rivers. The finding of elevated concentrations of acetylsalicylic acid is most likely a result of direct discharges of untreated sewage. Therefore, readily degradable pharmaceuticals may present larger concern in regions without consistent sewage treatment. Based on measured environmental concentrations, the risks of direct toxicity to aquatic wildlife and of humans consuming the water are discussed.     

Numerical characterization of the plasma arc with various Ar-CO2 mixtures

Environmental Science and Pollution Research - Plasma technology finds applications in many industrial areas. To improve the process efficiency, different plasma forming gases and their mixtures...