Impact of Coal Power Plant Emission on the Foliar Elemental Concentrations in Plants in a Low Rainfall Tropical Region

A field study was conducted around two thermal power plants of India to quantify the changes in foliar elemental concentrations due to emission in a low rainfall tropical area. Sulphur dioxide and particulates were at high levels which may cause serious ecological effects. Emission from the power plants has altered the elemental concentrations in the leaves of evergreen and deciduous plants. The foliar total-S and SO₄ ^2–-S levels were significantly higher in all the plants growing at polluted sites. However, the organic-S content was more or less unaltered. In evergreen plants, the SO₄ ^2–-S content increased gradually from summer through winter, whereas in the deciduous plants there was a higher magnitude of increase after onset of new leaves during summer. With the increasing pollution load, foliar Ca²⁺ and K⁺ contents increased, whereas N content decreased. The reduction in N content was greater during summer in evergreen plants and during winter in deciduous plants. The plants growing closer to the power plants accumulated more trace elements (Mn, Fe, Cd, Pb and Ni) as compared to those growing at distant sites. In deciduous plants the leaf fall during winter lowered down the trace element     

Applicability of high rate transpiration system for treatment of biologically treated distillery effluent

The biologically treated distillery effluent (BTDE) contains intense colour, high total dissolved solids (TDS), chemical oxygen demand (COD) and biochemical oxygen demand (BOD). These properties even after primary, secondary and tertiary treatments contain high concentrations of TDS, COD and BOD. The paper highlights the safe disposal and treatment of BTDE on land through High Rate Transpiration System (HRTS). HRTS is a zero discharge, low cost, high-tech method for improving the quality of BTDE for potential reuse. The experiments conducted at bench and pilot scale showed that HRTS having coconut husk as a bedding material could successfully treat the BTDE with a hydraulic load of 200 m³ ha⁻¹ day⁻¹ having BOD of 100 mg l⁻¹ and 500 m³ ha⁻¹ day⁻¹ having BOD of 500 mg l⁻¹ with average COD load of 0.686 and 2.88 ton ha⁻¹ day⁻¹ during the post and pre monsoon periods respectively. There was no significant increase in the organic carbon of the soil irrigated with BTDE. The concentrations of various pollutants analyzed in the leachate were within the prescribed limit for the drinking water sources. The colour removal was 99 to 100% and BOD and COD were possible to treat with optimum hydraulic loading of BTDE through HRTS planted with Dendrocalamus strictus.     

Emissions of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs) to air from waste incinerators and high thermal processes in India

This study investigated dioxins and dioxin-like polychlorinated biphenyls in gasses emitted from waste incinerators and thermal processes in central and western parts of India. The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/DFs) ranged from 0.0070 to 26.8140 ng toxicity equivalent (TEQ)/Nm³, and those of dioxin-like polychlorinated biphenyls (PCBs) ranged from 0.0001?×?10^?1 to 0.0295 ng TEQ/Nm³. The characteristics of mean PCDD/F I-TEQ concentration and congener profiles were studied over all the samples of air. In particular, a pattern consisting of a low proportion of dioxin-like PCBs and high proportion of PCDDs/DFs was common for all the samples from incinerators and high-temperature processes.     

Residual behavior of quizalofop ethyl on onion (Allium cepa L.)

Quizalofop ethyl, a phenoxy propionate herbicide, is used for postemergence control of annual and perennial grass weeds in broad-leaved crops in India. The experiments were designed to study the dissipation kinetics of quizalofop ethyl on onion for two seasons. A simple, rapid, and sensitive method for estimation of quizalofop ethyl residues in onion and soil was developed and validated. The recoveries of quizalofop ethyl residues from onion and soil at different spiking level range from 84.81 to 92.68 %. The limit of quantification of this method was found to be 0.01 μg g^?1. The risk assessment through consumption of the onion in comparison to its acceptable daily intake which is an important parameter for the safety of the consumer was also evaluated. Standardized methodology supported by recovery studies was adopted to estimate residues of quizalofop ethyl on onion and soil. The average initial deposits of quizalofop ethyl on onion were observed to be 0.25 and 0.33 mg kg^?1, following single application of the herbicide at 50 g active ingredient (a.i.) ha^?1 during 2009 and 2010, respectively. The half-life values (T _1/2) of quizalofop ethyl on onion crop were worked out to be 0.85 and 0.79 days, respectively, during 2009 and 2010. At harvest time, the residues of quizalofop ethyl on onion and soil were found to be below the determination limit of 0.01 mg kg^?1 following single application of the herbicide at 50 and 100 g a.i. ha^?1 for both the periods.     

Utility of non-timber forest products in a small watershed in the Indian Himalayas: the threat of its degradation

This study discusses the use of non-timber forest products (NTFP), especially medicinal plants, by traditional communities in the western Himalaya, India. The great socio-cultural diversity and ecological complexity of the region is also matched by an unusually large variety of forest species being used. A wide range of plants, comprising herbs, shrubs and trees are used for different domestic purposes, such as food, fodder, materials for construction and handicrafts. Wild plants also play a vital role in providing primary health care in the region. In earlier times, forest products were harvested only on a subsistence basis. However, in recent decades, factors such as rising market demand, increasing population pressure, and changes in socio-cultural and socio-economic values have led to overharvesting. It is now estimated that most of the useful wild herbs in the region are overexploited and some of them have become locally extinct. Government forestry policies have, in the past, exclusively emphasized plantation and management of trees and have, unfortunately, ignored non-timber products, as these are usually of comparatively lesser economic importance. However, it is suggested that proper management of NTFP will help upgrade rural economies. Recommended policies to this effect include empowerment of local communities and their involvement in development plans as well as strengthening of indigenous knowledge. To foster sustainable use of NTFP, the following steps are also suggested: integrating traditional and scientific knowledge; safeguarding regeneration potential; cultivating wild species, making appropriate changes to extraction processes used; and establishing more transparency in prices and marketing channels.     

Cellular uptake and mutagenic potential of metal oxide nanoparticles in bacterial cells

Extensive production and consumption of nanomaterials such as ZnO and TiO₂ has increased their release and disposal into the environment. The accumulation of nanoparticles (NPs) in ecosystem is likely to pose threat to non-specific targets such as bacteria. The present study explored the effect of ZnO and TiO₂ NPs in a model bacterium, Salmonella typhimurium. The uptake of ZnO and TiO₂ bare NPs in nano range without agglomeration was observed in S. typhimurium. TEM analysis demonstrated the internalization and uniform distribution of NPs inside the cells. Flow cytometry data also demonstrates that both ZnO and TiO₂ NPs were significantly internalized in the S. typhimurium cells in a concentration dependent manner. A significant increase in uptake was observed in the S. typhimurium treated even with 8 and 80 ng mL⁻¹ of ZnO and TiO₂ NPs with S9 after 60 min, possibly the formation of micelles or protein coat facilitated entry of NPs. These NPs exhibited weak mutagenic potential in S. typhimurium strains TA98, TA1537 and Escherichia coli (WP2uvrA) of Ames test underscoring the possible carcinogenic potential similar to certain mutagenic chemicals. Our study reiterates the need for re-evaluating environmental toxicity of ZnO and TiO₂ NPs presumably considered safe in environment.     

Local level community forest management an effective tool in conserving forest biodiversity

Forest vegetation of a community managed forest (Van Panchayat) located between 1570–1700 m elevation was studied along four aspects. Quercus leucotrichophora was the dominant species on three of the four aspects. Across the aspects the total tree density ranged between 150 and 490 ind/ha, sapling density between 100 and 370 ind/ha, seedling density varied from 241 to 1090 ind/ha. The shrub density ranged from 166 to 690 ind/ha and herb density from 6000–17100 ind/ha. The total basal area of tree layer varied from 9.78 to 13.5 m²/ha showing that the forest is young. Species diversity value for tree layer varied from 0.14 to 1.69. Quercus leucotrichophora were regenerating well due to effective forest management by local communities. The higher proportion of seedlings of Quercus leucotrichophora indicating that the Van Panchayat are playing important role in conservation of oak forest of Himalaya.     

Growth responses and metal accumulation capabilities of woody plants during the phytoremediation of tannery sludge

Five woody plants species (i.e. Terminalia arjuna, Prosopis juliflora, Populus alba, Eucalyptus tereticornis and Dendrocalamus strictus) were selected for phytoremediation and grow on tannery sludge dumps of Common Effluent Treatment Plant (CETP), Unnao (Uttar Pradesh), India. Concentration of toxic metals were observed high in the raw tannery sludge i.e. Fe-1667 > Cr-628 > Zn-592 > Pb-427 > Cu-354 > Mn-210 > Cd-125 > Ni-76 mg kg⁻¹ dw, respectively. Besides, physico-chemical properties of the raw sludge represented the toxic nature to human health and may pose numerous risks to local environment. The growth performances of woody plants were assessed in terms of various growth parameters such as height, diameter at breast height (DBH) and canopy area of plants. All the plant species have the capabilities to accumulate substantial amount of toxic metals in their tissues during the remediation. The ratio of accumulated metals in the plants were found in the order Fe > Cr > Mn > Pb > Zn > Cu > Cd > Ni and significant changes in physico-chemical parameters of tannery sludge were observed after treatment. All the woody plants indicated high bioconcentration factor for different metals in the order Fe > Cr > Mn > Ni > Cd > Pb > Zn > Cu. After one year of phytoremediation, the level of toxic metals were removed from tannery sludge up to Cr (70.22)%, Ni (59.21)%, Cd (58.4)%, Fe (49.75)%, Mn (30.95)%, Zn (22.80)%, Cu (20.46)% and Pb (14.05)%, respectively.     

Molluscicidal activity of Sapindus mukorossi and Terminalia chebula against the freshwater snail Lymnaea acuminata

The molluscicidal activity of Sapindus mukorossi and Terminalia chebula fruit powder against the vector snail Lymnaea acuminata was time and concentration dependent. The molluscicidal activity of T. chebula fruit powder (96 h LC(50):93.59 mg L(-1)) was more pronounced than that of S. mukorossi fruit powder (96 h LC(50):119.57 mg L(-1)). Ethanolic extracts of S. mukorossi and T. chebula fruit powder were more toxic than their other organic solvent extracts. The molluscicidal activity of ethanolic extract of S. mukorossi fruit powder (24h LC(50):2.75 mg L(-1)) was more effective than the ethanolic extract of T. chebula fruit powder (24h LC(50):124.06 mg L(-1)). The 96 h LC(50) of column-purified fraction of S. mukorossi fruit powder was 5.43 mg L(-1) whereas those of T. chebula fruit powder was 7.49 mg L(-1). Column, thin layer and high performance liquid chromatography analysis demonstrates that the active molluscicidal component in S. mukorossi and T. chebula is saponin (96 h LC(50):1.31 mg L(-1)) and tannic acid (96 h LC(50):1.64 mg L(-1)), respectively. These plants may be used as potent source of molluscicides against the snail L. acuminata.     

Phytotoxicity of composted herbal pharmaceutical industry wastes

This work demonstrates the phytotoxicity screening of composted herbal pharmaceutical industry waste (HPIW) using seed bioassay method. The composted industrial waste should be tested at lab scale prior to recommendation for land application. HPIW was mixed with soil to produce four treatments: T(1) (1:1), T(2) (1:2), T(3) (1:3), and T(4) (1:0) for toxicity screening using Pisum sativum seeds. After 72?h relative seed germination (RSG), relative root growth (RRG) and germination index (GI) were recorded. Seedlings were observed for further plant growth and tissue biochemistry (chlorophyll, soluble sugar, starch, carotenoid, and protein) estimation. RSG, RRG, and GI values were better in T(1) and T(2) than others. GI was in the ranges of 36.62?% (T(4)) to 170.38?% (T(2)). The seedling growth and biochemical parameters were better in seedling obtained from potting media containing low proportion of HPIW (i.e., T(1) and T(2)). Results clearly suggested that composted HPIW may be utilized effectively for crop production after dilution under sustainable farming system program.