The recent occurrence of exotic freshwater fishes in the tributaries of river Ganga basin: abundance, distribution, risk, and conservation issues

We record here the recent occurrence, abundance and distribution of six exotic fish species, viz. Oreochromis mossambicus, Cyprinus carpio, Hypopthalmicthys molitrix, Ctenopharyngodon idellus, Clarias gariepinus, and Pterygoplichthys disjunctivus (a new exotic in India) distributed through the four important tributaries of river Ganga basin in India. From the total catch, the abundance index of all exotic species in different rivers ranged from 1.1 to 14.5?% with highest value in River Gomti. The relative abundance of the exotic species in all the four tributaries demonstrated that a single species C. carpio contributed a considerable abundance (43.3?C83?%) than that of the remaining exotic fishes. The Common Carp, C. carpio, was ubiquitous in all the four tributaries of Ganges basin studied and had the highest local distribution (52.63?%). Smaller size groups of endangered (Chagunius chagunio, Chitala chitala, and Tor tor) and migratory species (Bagarius bagarius, Ompok pabda, Wallago attu, and Sperata aor) in the four tributaries were recorded, and the increasing appearance of Common Carp and other exotic fishes is signaling biological invasion. Possible threats to the indigenous fish fauna, as a result of the invasion and proliferation of these exotics, are discussed.     

Pollution due to hazardous glass waste

Pollution resulting from hazardous glass (HG) is widespread across the globe, both in terms of quantity and associated health risks. In waste cathode ray tube (CRT) and fluorescent lamp glass, mercury and lead are present as the major pollutants. The current review discusses the issues related to quantity and associated risk from the pollutant present in HG and proposes the chemical, biological, thermal, hybrid, and nanotechniques for its management. The hybrid is one of the upcoming research models involving the compatible combination of two or more techniques for better and efficient remediation. Thermal mercury desorption starts at 100 °C but for efficient removal, the temperature should be >460 °C. Involvement of solar energy for this purpose makes the research more viable and ecofriendly. Nanoparticles such as Fe, Se, Cu, Ni, Zn, Ag, and WS₂ alone or with its formulation can immobilize heavy metals present in HG by involving a redox mechanism. Straight-line equation from year-wise sale can provide future sale data in comparison with lifespan which gives future pollutant approximation. Waste compact fluorescent lamps units projected for the year 2015 is 9,300,000,000 units and can emit nearly 9,300 kg of mercury. On the other hand, CRT monitors have been continuously replaced by more improved versions like liquid crystal display and plasma display panel resulting in the production of more waste. Worldwide CRT production was 83,300,000 units in 2002 and can approximately release 83,000 metric tons of lead.     

Assessment of indoor air concentrations of VOCs and their associated health risks in the library of Jawaharlal Nehru University,New Delhi

The present work investigated the levels of total volatile organic compounds (TVOC) and benzene, toluene, ethylbenzene, m/p-xylene, and o-xylene (BTEX) in different microenvironments in the library of Jawaharlal Nehru University in summer and winter during 2011–2012. Carcinogenic and non-carcinogenic health risks due to organic compounds were also evaluated using US Environmental Protection Agency (USEPA) conventional approaches. Real-time monitoring was done for TVOC using a data-logging photo-ionization detector. For BTEX measurements, the National Institute for Occupational Safety and Health (NIOSH) standard method which consists of active sampling of air through activated charcoal, followed by analysis with gas chromatography, was performed. Simultaneously, outdoor measurements for TVOC and BTEX were carried out. Indoor concentrations of TVOC and BTEX (except benzene) were higher as compared to the outdoor for both seasons. Toluene and m/p-xylene were the most abundant organic contaminant observed in this study. Indoor to outdoor (I/O) ratios of BTEX compounds were generally greater than unity and ranged from 0.2 to 8.7 and 0.2 to 4.3 in winter and summer, respectively. Statistical analysis and I/O ratios showed that the dominant pollution sources mainly came from indoors. The observed mean concentrations of TVOC lie within the second group of the Molhave criteria of indoor air quality, indicating a multifactorial exposure range. The estimated lifetime cancer risk (LCR) due to benzene in this study exceeded the value of 1?×?10^?6 recommended by USEPA, and the hazard quotient (HQ) of non-cancer risk came under an acceptable range.     

Application of remote sensing techniques toward the role of traditional water bodies with respect to vegetation conditions

Sri Lanka being an agrarian country, the role of water is important for agricultural production. In Sri Lanka, various tank cascade systems, earthen dams and distribution canals have been accepted as few of the most complex ancient traditional water systems of the world. Rainfall, surface water, groundwater and runoff are linked with each other, they have close interactions to land cover classes such as forests and agriculture. The monitoring of vegetation conditions can show subsurface manifestations of groundwater. In this study, an effort to understand the role of traditional water reservoirs and groundwater recharge was made using remote sensing techniques. We have analyzed various vegetation indices such as Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI-2), Soil-Adjusted Vegetation Index (SAVI), tasselled cap transformation analysis (TCA brightness, greenness and wetness) and their relations with the existence of soil, vegetation and water. Result shows that EVI, SAVI, and TCA-based Greenness Index indicates good relationship with the vegetation conditions as compared to other indices. Therefore, these indices could play a crucial role in depicting the interaction between soil, vegetation, and water. However, multi-temporal observations can provide significant results about these interactions more accurately.     

Alumina-supported oxime for the degradation of sarin and diethylchlorophosphate

1-(4-Chlorophenyl))-N-hydroxymethanimine and cyclohexyl-N-hydroxymethanimine were synthesized and a well-established oxime, i.e., 2-[(hydroxyimino)methyl]-1-methylpyridinium chloride was purchased. Thereafter; all were loaded over Al₂O₃ using incipient wetness technique. The prepared systems were characterized using surface area analyzer, scanning electron microscope, energy dispersive X-ray spectrophotometer, Fourier transform infrared spectrophotometer and thermogravimetric analyzer. Kinetics of the degradation of sarin (GB) and simulant, i.e. diethylchlorophosphate (DEClP) was studied over synthesized oxime impregnated Al₂O₃ and results were compared with well reported oxime impregnated Al₂O₃. Kinetics of reaction was found to be following the pseudo first order reaction kinetics. The order of reactivity of the prepared systems was found to be cyclohexyl-N-hydroxymethanimine/Al₂O₃ > 1-(4-chlorophenyl)-N-hydroxymethanimine/Al₂O₃ > 2-[(hydroxyimino)methyl]-1-methylpyridinium chloride/Al₂O₃ > Al₂O₃. From the reaction kinetics it was observed that the reaction with DEClP was faster than with GB. Cyclohexyl-N-hydroxymethanimine/Al₂O₃ was found to be the most reactive system with half-life of 0.94 and 15 h for DEClP and GB respectively.     

Determination of sulfosulfuron residues in soil under wheat crop by a novel and cost-effective method and evaluation of its carryover effect

A novel and cost-effective method of sulfosulfuron extraction has been developed using distilled water as an extraction solvent. Using this method, the environmental fate of sulfosulfuron was investigated in soil under wheat crop. Studies were conducted under natural field conditions in randomized block design and herbicide (75% water dispersible granules (WG)) was applied after 24 days of sowing. The rates of applications were 25 and 50 g of active ingredient (a.i.) per hectare. Soil samples were collected at predetermined intervals and analyzed by high performance liquid chromatography (HPLC). The minimum detection limit was found to be 0.001 μ g g^{? 1}. The dissipation of sulfosulfuron followed first-order rate kinetics and dissipated with a half-life of 5.4–6.3 days. After harvest, field soil was used for conducting a pot experiment with bottle gourd (Lagenaria siceraria) as test plants to study the carry over effect of sulfosulfuron. No phytotoxicity was observed to bottle gourd in pot experiment with harvest soil.     

Persistence of hexaconazole,a triazole fungicide in soils

Abstract

Persistence of hexaconazole (2‐(2,4‐dichlorophenyl)‐l‐(lH‐l,2,5‐triazol‐l‐yl) hexan‐2‐ol) was studied in alluvial, red and black soils under flooded and nonflooded conditions. This fungicide was more persistent in all soils under flooded conditions than under nonflooded conditions and at 27°C than at 35°C. Degradation of hexaconazole in sterilized and nonsterilized soils proceeded at identical rates indicating a minor role of micro‐organisms in its degradation. The soil persistence of hexaconazole was not affected by the addition of wheat straw both under flooded and nonflooded conditions.     

Effect of UV radiation and temperature on mineralization and volatilization of coumaphos in water

This study was undertaken to determine the dissipation and degradation of coumaphos [O-(3-chloro-4-methyl-2-oxo-2H-1-benzopyran-7-yl) O,O-diethyl phosphorothioate] under different sunlight conditions and at different temperatures. The effect of the ultra violet (UV) component of solar radiation was also studied using quartz tubes in addition to other radiation in the visible range using glass tubes and the results were compared with those obtained under the dark light conditions. Water suspensions of coumaphos were incubated at three temperatures viz. 22 degrees C, 37 degrees C and 53 degrees C in closed systems to study the effect of temperature. Volatilization, mineralization and degradation of coumaphos increased with an increase in temperature and exposure to solar radiation, particularly under the UV component of the solar radiation. Major loss of the pesticide occurred through volatilization. The optimum temperature for the degradation of coumaphos was found to be at 37 degrees C. The data obtained from the mineralization and degradation studies indicated that 53 degrees C crosses the biological range for suitable growth of microorganism. UV radiation exposure along with maintaining temperature at 37 degrees C may prove useful in the dissipation and/or degradation of coumaphos prior to its disposal as waste from cattle dipping vats.     

House fly (Musca domestica): a review of control strategies for a challenging pest

Musca domestica L. (Diptera: Muscidae), commonly called the house fly, is a major domestic, medical and veterinary pest that causes irritation, spoils food and acts as a vector for many pathogenic organisms. In this paper, the social and health problems related to housefly are introduced with the associated need to control its population. Physical and chemical methods of house fly control are briefly discussed. The main focus of this review is on the biological control methods for house fly control, that comprise botanical, fungal, bacterial and parasitoid agents. Although several biocontrol agents are still in the nascent stage, some of them (especially fungal and parasitoid agents) have shown reliable field performance and seem to be suitable candidates for commercialization. However, the majority of these laboratory and field studies have been conducted in the temperate region. It remains to be seen whether the application of biocontrol agents would be feasible in tropical environments. The integrated pest management practices, which can provide more reliable field performance, have also been discussed. A multi-dimensional approach that exerts control on all the life stages of house fly, but simultaneously preserves the fly's natural enemies could be an ecologically sustainable way of maintaining the fly populations below maximally acceptable limits.     

The effect of temperature on PAHs emission from incineration of acrylic waste

Incineration of acrylic waste solution in a lab scale quartz tube vertical incinerator showed the presence of 12–15 polycyclic aromatic hydrocarbons (PAHs) from a list of 16 priority pollutants at 700–1100^˚C after an interval of 50^˚C. The amount of total 16 PAHs at 900 and 1100^˚C was about 8.5 and 1.25 times higher than those at 700^˚C (739.48 μg g⁻¹) respectively. The amount of total probable (2A) and possible (2B) human carcinogenic PAHs was minimum at 700^˚C.