A study on the waste metal remediation using floriculture at East Calcutta Wetlands, a Ramsar site in India

Use of specific plant species in remediation of heavy metal-contaminated soil and water was a promising eco-friendly technology. The present study indicated the possibilities of phytoremediation of metal-contaminated (namely Ca, Cr, Mn, Fe, Cu, Zn, and Pb) soil by using plant species important for floriculture of East Calcutta Wetlands, a Ramsar site at the eastern fringe of Calcutta city. Plant species like sunflower (Helianthus annuus), marigold (Tagetes patula), and cock's comb (Celocia cristata) grew on soil contaminated by industrial sludge and irrigated regularly with wastewater accumulated different metals in different plant parts in varied concentrations. Pot culture study in the laboratory setup was also done to ascertain the efficiency of these plants for ameliorating contaminated soil. It was found that general accumulation patterns of metals concerned in different plant parts were root > leaf > stem > flower. This work indicated the importance of cultivation of economically important, non-edible, ornamental plant species as an alternative cost-effective practice to remediate heavily contaminated farmlands of East Calcutta Wetlands.     

Influence of mercury from fly ash on cattle reared nearby thermal power plant

Cattle grazing nearby coal-fired power stations are exposed to fly ash. The present investigation aims to assess the environmental and health impacts of fly ash containing mercury emitted from thermal power plant. The health effect of fly ash were studied using 20 lactating cattle reared within a 5-km radius of s thermal power plant for the possible effect of fly ash such as the alterations in hematological and biochemical parameters of blood, milk, and urine. Results indicated that the hemoglobin levels (6.65?±?0.40?g/dl) were significantly reduced in all the exposed animals. Biochemical parameters viz., blood urea nitrogen (27.35?±?1.19?mg/dl), serum glutamate oxaloacetate transaminase (43.39?±?3.08?IU/l), albumin, and creatinine were found to be increased, whereas serum glutamate pyruvic transaminase (29.26?±?2.02) and Ca²⁺ were observed to be statistically insignificant in exposed animals. Mercury concentrations estimated in the blood, milk, and urine of exposed (n?=?20) and control (n?=?20) animals were 7.41?±?0.86, 4.75?±?0.57, 2.08?±?0.18, and 1.05?±?0.07, 0.54?±?0.03, 0.20?±?0.02?μg/kg, respectively. The significant increase (P?<?0.01) in the levels of mercury in blood, milk, and urine of exposed animals in comparison to control indicated that the alterations of biochemical parameters in exposed cattle could be due to their long term exposure to fly ash mercury which may have direct or indirect impact on human populations via food chain.     

Idle Emissions from Heavy-Duty Diesel Vehicles: Review and Recent Data

Abstract

Heavy-duty diesel vehicle idling consumes fuel and reduces atmospheric quality, but its restriction cannot simply be proscribed, because cab heat or air-conditioning provides essential driver comfort. A comprehensive tailpipe emissions database to describe idling impacts is not yet available. This paper presents a substantial data set that incorporates results from the West Virginia University transient engine test cell, the E-55/59 Study and the Gasoline/Diesel PM Split Study. It covered 75 heavy-duty diesel engines and trucks, which were divided into two groups: vehicles with mechanical fuel injection (MFI) and vehicles with electronic fuel injection (EFI). Idle emissions of CO, hydrocarbon (HC), oxides of nitrogen (NO_x), particulate matter (PM), and carbon dioxide (CO₂) have been reported. Idle CO₂ emissions allowed the projection of fuel consumption during idling. Test-to-test variations were observed for repeat idle tests on the same vehicle because of measurement variation, accessory loads, and ambient conditions. Vehicles fitted with EFI, on average, emitted [~20 g/hr of CO, 6 g/hr of HC, 86 g/hr of NO_x, 1 g/hr of PM, and 4636 g/hr of CO₂ during idle. MFI equipped vehicles emitted ~35 g/hr of CO, 23 g/hr of HC, 48 g/hr of NO_x, 4 g/hr of PM, and 4484 g/hr of CO₂, on average, during idle. Vehicles with EFI emitted less idleCO, HC, and PM, which could be attributed to the efficient combustion and superior fuel atomization in EFI systems. Idle NO_x, however, increased with EFI, which corresponds with the advancing of timing to improve idle combustion. Fuel injection management did not have any effect on CO₂ and, hence, fuel consumption. Use of air conditioning without increasing engine speed increased idle CO₂, NO_x, PM, HC, and fuel consumption by 25% on average. When the engine speed was elevated from 600 to 1100 revolutions per minute, CO₂ and NO_x emissions and fuel consumption increased by >150%, whereas PM and HC emissions increased by ~100% and 70%, respectively. Six Detroit Diesel Corp. (DDC) Series 60 engines in engine test cell were found to emit less CO, NO_x, and PM emissions and consumed fuel at only 75%of the level found in the chassis dynamometer data. This is because fan and compressor loads were absent in the engine test cell.     

Fish scales as bio-indicator of water quality of River Ganga

Various studies have been conducted in the past on the fresh waters related to the various aspects of limnology, physico-chemistry, primary productivity, plankton etc. in relation to environmental conditions and ecology, flora and fauna of River Ganga. In the present investigation some recent approach have been made to study the various parts of fishes like gill structures, scales for age determination, length and weight of fish for growth assessments etc. The SEM study of scales in relation to pollution and environmental conditions is a recent approach. At this stage, in the present study the scales of two most common fishes found in the study stretch were involved to create a base line.     

Comparative study on the effect of chemicals on Alternaria blight in Indian mustard--a multi-location study in India

High severity of Altemaria blight disease is a major constraint in production of rapeseed-mustard in India. The aim of this study was to investigate the suppressive potential of chemicals viz., zinc sulphate, borax, sulphur, potash and calcium sulphate, aqueous extracts viz., Eucalyptus globosus (50 g l-1) leaf extract and garlic (Allium sativum) bulb (20 g l-1) extract, cow urine and bio-agents Trichoderma harzianum, Pseudomonas fluorescence in comparison with the recommended chemical fungicide (mancozeb), against foliar disease Alternaria blight of Indian mustard [Brassica juncea (L.) Czern. and Coss] under five different geographical locations of India. Mancozeb recorded the lowest mean severity (leaf: 33.1%; pod: 26.3%) of Alternaria blight with efficacy of garlic bulb extract alone (leaf = 34.4%; pod = 27.3%) or in combination with cow urine (leaf = 34.2%; pod = 28.6%) being statistically at par with the recommended chemical fungicide. Chemicals also proved effective in reducing Alternaria blight severity on leaves and pods of Indian mustard (leaf = 36.3-37.9%; pod = 27.5-30.1%). The effective treatments besides providing significant reduction in disease severity also enabled increase in dry seed yield of the crop (mancozeb = 2052 kg ha-1; garlic = 2006 kg ha-1; control = 1561 kg ha-1).     

Dental fluorosis—a case study from Nawa tehsil in Nagaur district,Rajasthan (India)

A study was carried out in Nawa tehsil of Nagaur district to assess the prevalence of dental fluorosis and its crippling effect due to ingestion and prolonged exposure of fluoride over a long period of time. During the survey of the study area, high concentration of fluoride (14.62 ppm) has been recorded. The presence of fluoride in quantities in excess of limits is a serious matter of concern from a public health point of view. Due to higher fluoride level in groundwater, several cases of dental fluorosis have appeared at alarming rate in the study area. The children’s teeth are damaged and are characterized by black and brown stains as well as cracking and pitting of the teeth have been observed. In the study area, 93.12% population suffered from dental fluorosis, and it was more prevalent in men (94.90%) than in women (90.00%). Dental fluorosis was also examined according to different grades. Out of the total 72 afflicted, in the 4–16-year age group, 41.46% were suffering from Grade I, Grade II was more prevalent in 33.85% of the 17–28-year age group and similarly Grade II was more prevalent in 39.13% of the 29–40-year age group. In the age group of above 40 years, grade III and grade IV were more prevalent. Thus, in the higher age group, the prevalence and severity of fluorosis is almost certainly due to longer exposure to fluoride. The major risk factor consistently identified for dental fluorosis was the consumption of fluoridated drinks and fluoride supplements. Ingestion of calcium, vitamin D and vitamin C is effective in protection from fluoride toxicity to certain extent.     

Effect of mercury and methyl parathion on the ovaries of Labeo rohita (Ham)

Adult pre-spawning fish Labeo rohita were sublethally (1/5th 96h LC50) exposed to mercuric chloride and metacid-50 (methyl parathion). Accumulation of mercury and methyl parathion was studied and it was found that pre-spawning ovary appears as a potent organ for deposition of both the pollutants. RNA/DNA ratio of the control and treated fish were studied. It was found that the signifcant decrease in RNA/DNA ratio occurs after 9 and 30 days of exposure for mercury and 30 days for methyl parathion. Fluorescence microscopic studies by acridine orange staining method were also performed to show how much it is related to biochemical alterations. In some cases loss of metachromasia is correlated with the fall in RNA/DNA ratio. Some other abnormalities like fall in stage II: stage I oocyte ratio and necrosis was also observed.     

Increasing bioavailability of phosphorus from fly ash through vermicomposting

Due to the environmental problems created by large-scale fly ash generation throughout the world, efforts are being made to recycle these materials. An important component of the recycling effort is using fly ash to improve low-fertility soils. Because availability of many nutrients is very low in fly ash, available ranges of such nutrients must be improved to increase the effectiveness of fly ash as a soil amendment. In the present study, we assessed the possibility of increasing P bioavailability in fly ash through vermicomposting in a yard experiment. Fly ash was mixed with organic matter in the form of cow (Bos taurus) dung at 1:3, 1:1, and 3:1 ratios and incubated with and without epigeic earthworm (Eisenia fetida) for 50 d. The concentration of phosphate-solubilizing bacteria (PSB) was found to increase many fold in the earthworm-treated series of fly ash and organic matter combinations compared with the series without earthworm. This helped to transform considerable amounts of insoluble P from fly ash into more soluble forms and thus resulted in increased bioavailability of the nutrients in the vermicomposted series. Among different combinations of fly ash and organic matter, P availability in fly ash due to vermicomposting was significantly higher in the 1:1 fly ash to cow dung treatment compared with the other treatments.     

Effect of noise exposure (85 dB ) on testicular adrenocortical steroidogenic key enzymes, acid and alkaline phosphatase activities of sex organs in mature albino rats

Changes in the activities of △5-3β-hydroysteroid dehydrogenase (HSD) in testis and adrenal gland, 17β-hydroxysteroid dehydrogenase in testis, acid and alkaline phosphatase in testis, prostate and seminal vesicle were observed in noise exposed mature rats at the intensity of 85 dB for 8 h/day for 45 days. The results indicated that noise exposed group showed a significant diminution in the activities of androgenic key enzymes △5-3β and 17β-HSD, acid phosphatase in testis, prostate and seminal vesicle. There was a significant elevation in the activities of adrenal △5-3β-HSD, alkaline phosphatase in testis and other accessory sex organ in noise exposed group. Gonadosomatic, prostatosomatic and seminal vesiculo-somatic indexes were decreased significantly in noise exposed group. Therefore, it is evident that noise exposure at 85dB exerts a deleterious effect on testicular and adrenocortical activities.