Statistical Analysis of Trends in Urban Ozone Air Quality

The purpose of this paper is to demonstrate the use of some statistical methods for examining trends in ambient ozone air quality downwind of major urban areas. To this end, daily maximum 1 -hr ozone concentrations measured over New Jersey, metropolitan New York City and Connecticut for the period 1980 to 1989 were assembled and analyzed. This paper discusses the application of the bootstrap method, extreme value statistics and a nonparametric test for evaluating trends in urban ozone air quality. The results indicate that although there is an improvement in ozone air quality downwind of New York City, there has been little change in ozone levels upwind of New York City during this ten-year period.     

Photocatalytic ozonation of pesticides in a fixed bed flow through UVA-LED photoreactor

In this study, a fixed bed flow through UVA-LED photoreactor was used to compare the efficiency of ozone, photocatalysis and photocatalysis-ozone degradation, and mineralization of two pure pesticides, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-methyl-4-chlorophenoxyacetic acid (MCPA), and a commercial one, Killex®. For the degradation of the parent compounds, ozone-based processes were more effective. While for mineralization, photocatalytic processes were more effective. Photocatalytic ozonation was the most efficient process for both the degradation and mineralization of the parent compounds. The degradation rates and mineralization by photocatalytic ozonation were higher than the summation of the corresponding rates by ozonation and photocatalysis, indicating a symbiotic relationship.Overall, the photocatalytic ozonation process with the fixed bed TiO₂ reduces the time needed for the degradation and mineralization of the pesticides, reduces the costs of powder catalyst separation and overcomes the reduced efficiency of immobilized catalysts, which makes the process quite attractive for practical applications.     

Assessing the potentials of Lemna minor in the treatment of domestic wastewater at pilot scale

Water crisis is one of the most serious problems faced by the world today. Phytoremediation is one of the serious efforts towards sustainability. Macrophyte-based wastewater treatment systems have several potential advantages compared with conventional treatment systems. Duckweeds (Lemna spp., Spirodela spp., Wolffia spp.) are small, green freshwater, free-floating aquatic plants. The primary objective of this work was to analyze the role of duckweeds in organic waste and nutrient removal from domestic wastewater being generated from hostels of Birla Institute of Technology, Mesra, Ranchi (India). Interesting results were obtained in which the BOD value reduced by 94.45% and the level of orthophosphate at the end of the work was found to be reduced by 79.39%. The duckweeds flourished well during the experimental period in the pH range of 7 to 8; it can be said that, other factors remaining favorable, the optimum pH for duckweed growth ranges from 7 to 8. Therefore, it can be concluded that this treatment can be successfully carried out on a large scale. Also, it is a low-cost solution to wastewater treatment problems and could satisfy the discharge standards.     

Water quality assessment of Majhiaon block of Garwa district in Jharkhand with special focus on fluoride analysis

Fluoride in groundwater is known to contaminate the water sources globally. Jharkhand, one of the states in the eastern part of India, is known to have excessive fluoride content in groundwater sources. The present work involves assessment of water quality with special reference to fluoride in Majhiaon block of Garwa district in Jharkhand. Iron, nitrate and arsenic were also tested for the water samples collected from site. Eight hundred forty samples were tested for fluoride on site using colourimetry method, and one tenth of the samples were brought to laboratory for iron, nitrate, arsenic and fluoride analysis. Results show that 402 samples were having fluoride above permissible limit. Iron and nitrate were found to be beyond permissible limits in 302 and 286 water samples, respectively. More than 50% of samples collected from school had fluoride levels above permissible limits. Arsenic was well within the limits. However, few samples shown were excessive of iron and nitrate.     

Studies on urban drinking water quality in a tropical zone

Anthropogenic activities associated with industrialization, agriculture and urbanization have led to the deterioration in water quality due to various contaminants. To assess the status of urban drinking water quality, samples were collected from the piped supplies as well as groundwater sources from different localities of residential, commercial and industrial areas of Lucknow City in a tropical zone of India during pre-monsoon for estimation of coliform and faecal coliform bacteria, organochlorine pesticides (OCPs) and heavy metals. Bacterial contamination was found to be more in the samples from commercial areas than residential and industrial areas. OCPs like α,γ-hexachlorocyclohexane and 1,1 p,p-DDE {dichloro-2, 2-bis(p-chlorophenyl) ethene)} were found to be present in most of the samples from study area. The total organochlorine pesticide levels were found to be within the European Union limit (0.5 μg/L) in most of the samples. Most of the heavy metals estimated in the samples were also found to be within the permissible limits as prescribed by World Health Organization for drinking water. Thus, these observations show that contamination of drinking water in urban areas may be mainly due to municipal, industrial and agricultural activities along with improper disposal of solid waste. This is an alarm to safety of public health and aquatic environment in tropics.     

Determination of pesticide residues in IPM and non-IPM samples of mango (Mangifera indica)

Studies were conducted to analyze the residue of commonly used pesticides viz. methyl parathion, chloropyrifos, endosulfan, cypermethrin, fenvalerate, carbendazim, imidacloprid and carbaryl in mango, Dashehari variety, integrated pest management (IPM) and non-IPM samples were collected from the IPM and non-IPM orchards, Lucknow, India. We also present a method for the simultaneous determination of these pesticides in mango samples. Residues of methyl parathion, chloropyriphos, endosulfan, cypermethrin, fenvalerate were extracted from the samples with acetone: cyclohexane: ethyl acetate in the ratio 2:1:1 followed by cleanup using neutral alumina. Analysis was performed by gas chromatography-electron capture detector (GC-ECD) with a megabore column (OV-1). Residues of carbendazim, imidacloprid and carbaryl were extracted with acetone and after cleanup, analysis was performed by high performance liquid chromatography (HPLC) using photo diode array (PDA) detector. Recoveries of all the pesticides ranged between 72.7-110.6%, at 0.1 and 1.0 microg g(-1) level of fortification. The residues detected in non-IPM samples of mango were found to be below the prescribed limits of maximum residue limit (MRL) while IPM samples were free from pesticide residues.     

Ascorbic acid supplementation of diet for reduction of deltamethrin induced stress in freshwater catfish Clarias gariepinus

Static bioassays were made to evaluate efficiency of supplementation of ascorbic acid to remove stress of pyrethroid pesticide deltamethrin from freshwater catfish Clarias gariepinus. Clarias gariepinus exhibited several symptoms of stress when treated with deltamethrin (0.005 mg/l) for 24 h. Hepatosomatic index, liver glycogen, ascorbic acid of blood, liver, and kidney decreased while plasma glucose levels increased. Fish previously fed for 60 days with a diet supplemented by a high level of ascorbic acid (100 mg/100 g) could remove most of the stresses. Low levels of ascorbic acid supplement did not remove the stress. Dietary supplement of ascorbic acid at also appropriate level appeared to be a good way to counter toxicity of deltamethrin to the catfish.     

Distribution of heavy metals in sediment and water of river Gomti

Gomti river receives industrial as well as domestic wastes from various drains of Lucknow city. In the process the water and sediment of the river Gomti get contaminated with heavy metals and other pollutants. In the present study, impacts of domestic/industrial wastes on the water and sediment chemistry of river Gomti with special reference to heavy metals have been investigated in different seasons (summer, winter and rainy). For this, seven sampling sites: Gaughat, Mohan Meakin, Martyrs Memorial, Hanuman Setu, Nishatganj bridge, Pipraghat and Malhaur, in the river Gomti in Lucknow region were identified and samples of water and sediments were collected in all the three seasons. In the collected water and sediment samples, six metals (Cd, Cr, Cu, Ni, Pb, and Zn) were analyzed on ICP-AES (Inductively coupled plasma emission spectroscopy) Labtam Plasmalab 8440. High concentrations of all the metals were noticed in water and sediment in rainy season compared to summer and winter. Because in rainy season runoff from open contaminated sites, agricultural field and industries, directly comes into the river without any treatment. In both the cases, the concentration of zinc was maximum (0.091 g/ml in water and 182.13 g/g in sediment) and the concentration of cadmium (0.001 g/ml in water and 17.26 g/g in sediment) was minimum. Higher concentration of metal in water and sediment during rainy season could be due to the industrial/agricultural/domestic runoff coming into the river.     

Aminolytic Depolymerization of Polyethylene Terephthalate Wastes Using Sn-Doped ZnO Nanoparticles

Journal of Polymers and the Environment - Poly(ethylene terephthalate) (PET) is one of the most consumed polymers because of its excellent thermal and mechanical properties. By increasing in PET...     

Influence of land use on metal concentrations in playa sediments and amphibians in the Southern High Plains

The Southern High Plains (SHP) is a semi-arid region in which playa wetlands are the focal points of biodiversity. Playas are highly influenced by surrounding land use. Most of the SHP is in agricultural production (primarily cotton) with a history of arsenic-containing herbicide use. Metals influence reproduction and development in amphibians. We analyzed metal residues in playa sediment and whole body tissue of Spea spp. and Bufo cognatus metamorphs from two land uses: cropland and native grassland. Cd and Ni concentrations in B. cognatus tissues differed between land uses. Metal concentrations in Spea spp. tissues did not differ between land uses. Ba was higher in Spea spp. than B. cognatus collected from the same grassland playas, indicating differential habitat use. No correlations between sediment and tissue concentrations were found. Land use appeared to have little influence on metal concentrations and levels were below those known to cause effects in amphibians.