Integrated water management of the Brahmaputra basin: Perspectives and hope for regional development

Water is strongly linked with the overall development framework of the Brahmaputra basin. However, the absence of integrated management of Brahmaputra water resources and lack of coordination among the riparian states constitutes an ongoing threat to future development plans within the basin. Brahmaputra's abundant hydropower potential can help give riparian countries a safer energy future that is the key driving force behind the prospect of potential cooperation. This paper analyses the current status of Brahmaputra water resources and identifies the perspectives of riparian countries regarding the development of the Brahmaputra basin. It also identifies the opportunities for cooperation and regional development through integrated water development and management of the Brahmaputra basin. It is essential to develop an integrated water resources management approach involving all riparians to foster regional development and overcome the prospect of severe water conflict along the Brahmaputra basin.     

Label-free colorimetric nanosensor with improved sensitivity for Pb2+ in water by using a truncated 8–17 DNAzyme

• Unmodified-AuNP based, colorimetric nanosensor was constructed for Pb²⁺ detection. • 5-nucleotide truncation in DNAzyme made complete substrate detachment upon Pb²⁺. • Ultrasensitive and selective detection of Lead (II) was achieved with 0.2×10^-9 mol/L LOD. Water pollution accidents, such as the Flint water crisis in the United States, caused by lead contamination have raised concern on the safety of drinking water distribution systems. Thus, the routine monitoring of lead in water is highly required and demands efficient, sensitive, cost-effective, and reliable lead detection methods. This study reports a label-free colorimetric nanosensor that uses unmodified gold nanoparticles (AuNPs) as indicators to enable rapid and ultra-sensitive detection of lead in environmental water. The 8–17 DNAzyme was truncated in this study to facilitate the detachment of single-stranded DNA fragments after substrate cleavage in the presence of Pb²⁺. The detached fragments were adsorbed over AuNPs and protected against salt concentration-induced aggregation. Accordingly, high Pb²⁺ would result in rapid color change from blue to pink. The established sensing principle achieved a sensitive limit of detection of 0.2×10^-9 mol/L Pb²⁺, with a linear working range of two orders of magnitude from 0.5×10^-9 mol/L to 5×10^-9 mol/L. The selectivity of the nanosensor was demonstrated by evaluating the interfering metal ions. The developed nanosensor can serve as a substitute for the rapid analysis and monitoring of trace lead levels under the drinking water distribution system and even other environmental water samples.     

A review on application of dielectric barrier discharge plasma technology on the abatement of volatile organic compounds

• Applications of non-thermal plasma reactors for reduction of VOCs were reviewed. • Dielectric barrier discharge (DBD) plasma was considered. • Effect of process parameters was studied. • Effect of catalysts and inhibitors were evaluated. Volatile organic compounds (VOCs) released from the waste treatment facilities have become a significant issue because they are not only causing odor nuisance but may also hazard to human health. Non-thermal plasma (NTP) technologies are newly developed methods and became a research trend in recent years regarding the removal of VOCs from the air environment. Due to its unique characteristics, such as bulk homogenized volume, plasma with high reaction efficiency dielectric barrier discharge (DBD) technology is considered one of the most promising techniques of NTP. This paper reviews recent progress of DBD plasma technology for abatement of VOCs. The principle of plasma generation in DBD and its configurations (electrode, discharge gap, dielectric barrier material, etc.) are discussed in details. Based on previously published literature, attention has been paid on the effect of DBD configuration on the removal of VOCs. The removal efficiency of VOCs in DBD reactors is presented too, considering various process parameters such as initial concentration, gas feeding rate, oxygen content and input power. Moreover, using DBD technology, the role of catalysis and inhibitors in VOCs removal are discussed. Finally, a modified configuration of the DBD reactor, i.e. double dielectric barrier discharge (DDBD) for the abatement of VOCs is discussed in details. It was suggested that the DDBD plasma reactor could be used for higher conversion efficiency as well as for avoiding solid residue deposition on the electrode. These depositions can interfere with the performance of the reactor.     

Synthesis,extraction, and identification of light polycyclic aromatic hydrocarbons (PAH) in microwave oven fried Aseel chicken tissues

The present study was conducted to determine the effects of microwave oven frying on production of four, light polycyclic aromatic hydrocarbons (PAH) anthracene, fluorene, phenathrene, and pyrene in four tissues heart, liver, neck, and wings of Aseel chickens. The microwave oven-fried samples of tissues along with respective control after appropriate preparation were analyzed using high-performance liquid chromatography. These PAH were identified by comparing retention time of the unknown with known ones and concentration was calculated. Data showed that among the four chicken tissues, the neck contained the maximum level (0.079 mg/kg) of anthracene while wings contained the minimum (0.006 mg/kg). Similarly, in case of flourene, the fried heart showed greater percentage increase (225.04%) while wings showed 16.18% fluorene compared with other two organs, while phenanthrene and pyrene were maximal in wings at 0.249 mg/kg and 0.094 mg/kg, respectively. Results demonstrate that high-temperature treatment such as microwave oven frying of chicken meat might be responsible to generate these toxicants. Further study is to determine the production of other PAH under the different barbecuing conditions using various meat varieties.     

Heavy metal accumulation and ecosystem engineering by two common mine site-nesting ant species: implications for pollution-level assessment and bioremediation of coal mine soil

The present study focuses on the abundance, heavy metal content, and the impact of ecosystem engineering activities of two coal mine site-inhabiting ant species, Cataglyphis longipedem and Camponotus compressus. The abundance of Ct. longipedem increased while that of C. compressus decreased, with increasing soil pollution. Correspondence analysis reveals a close association between soil heavy metal concentrations and Ct. longipedem abundance, but this association is lacking in the case of C. compressus. Cataglyphis ants which occupy stress-characterized niches appear to be pre-adapted to tolerate heavy metal pollution. Higher concentrations of Zn and Mn in Ct. longipedem may contribute to the strengthening of the cuticular structures, necessary for nest excavation in the hard, arid soil and for single load carrying. C. compressus ants appear to be pollution sensitive. Their higher Fe content may be related to metal uptake via plant-derived liquids and species-specific regulatory mechanisms. The metal pollution index and biota-to-soil accumulation factors, calculated by using the ant body metal content of the two species, indicate an overall decrease of soil heavy metal concentrations with increase of the site age, which reflects the degree of pollution related to the mine site age. The concentrations of total and available heavy metals (Fe, Zn, Mn, Pb, and Cu) were significantly lower in the ant nest debris soil as compared to the reference soil. The results of the present study highlight the role of ants as bioindicators and in bioremediation of contaminated soil.     

Simulation of mixing depths incorporating the urban heat island effect

The main objective of this paper was to establish the effect of anthropogenic heat flux on the formation of mixing depth specially in urban areas. In this study an energy balance mixing depth model was developed for the simulation of mixing depth incorporating the heat island effect. To demonstrate the effect of heat island, mixing depths were simulated under two conditions. Under the first condition, hourly gridded anthropogenic heat flux and variant surface characteristics were considered, while under the second condition anthropogenic heat flux term was ignored and constant surface characteristics were considered throughout the modelling domain. The release of anthropogenic heat flux in the urban environment was found to be responsible for the growth of the unstable layer in the lower atmosphere even during the night. This resulted in higher mixing depth values in urban areas compared to the surrounding countryside. The maximum differential surfaces sensible heat flux between urban and rural areas was estimated as 130 W/m². From the simulation of mixing depth, it was revealed that the maximum increment in mixing depth in urban areas was 300 m due to the heat island effect. This increment in mixing depth in urban areas can provide an extra space for dilution and mixing of pollutants.     

Does Globalisation Worsen Environmental Quality in Developed Economies?

We examine the causal relationship between globalisation and CO₂ emissions for 25 developed economies in Asia, North America, Western Europe and Oceania using both time series and panel data techniques, spanning the annual data period of 1970–2014. Because of the presence of cross-sectional dependence in the panel, we employ Pesaran’s Journal of Applied Econometrics 22, 265–312 (2007) cross-sectional augmented panel unit root (CIPS) test to ascertain unit root properties. The Westerlund Oxford Bulletin of Economics and Statistics 69, 709–748 (2007) cointegration test is also used to ascertain the presence of a long-run association between globalisation and carbon emissions. The long-run heterogeneous panel elasticities are estimated using the Pesaran Econometrica, 74(4), 967–1012 (2006) common correlated effect mean group (CCEMG) estimator and the Eberhardt and Teal Productivity analysis in global manufacturing production (2010) augmented mean group (AMG) estimator. The causality between the variables is examined by employing the Dumitrescu and Hurlin Economic Modelling, 29, 1450–1460 (2012) and Emirmahmutoglu and Kose Economic Modelling, 28, 870–876 (2011) Granger causality tests. The empirical results reveal that globalisation increases carbon emissions, and thus, the globalisation-driven carbon emission hypothesis is valid. This empirical analysis suggests insightful policy guidelines for policy makers using ‘globalisation’ as an economic tool for better long-run environmental policy.     

Metal pollution and ecological risk assessment in marine sediments of Karachi Coast, Pakistan

Concentrations of 12 metals (Fe, Mn, Cr, Mo, Ni, Pb, Se, Sr, U, V, Zn, and Zr) in surface sediments of Karachi Coast, Pakistan were determined to evaluate their distribution and pollution assessment. The measured metals in the sediments were found to be in the range of Fe, 0.84–6.96 %; Mn, 300–1,300 μg/g; Cr, 12.0–319.84 μg/g; Mo, 0.49–2.03 μg/g; Ni, 1.53–58.86 μg/g; Pb, 9.0–49.46 μg/g; Se, 0.25–.86 μg/g; Sr, 192–1185 μg/g; U, 0.19–1.66 μg/g; V, 15.80–118.20 μg/g; Zn, 15.60–666.28 μg/g; and Zr, 44.02–175.26 μg/g. The mean contents of the metal studied were: Fe, 3.07 %, Mn, 0.05 %; Cr, 96.75 μg/g; Mo, 1.34 μg/g; Ni, 31.39 μg/g; Pb, 23.24 μg/g; Se, 0.61 μg/g; Sr, 374.83 μg/g; U, 0.64 μg/g; V, 61.75 μg/g; Zn, 204.75 μg/g; and Zr:76.27 μg/g, and arrangement of the metals from higher to lower mean content in this area is: Fe?>?Zn?>?Mn?>?Sr?>?Zn?>?Cr?>?Zr?>?V?>?Ni?>?Pb?>?Mo?>?U?>?Se. There is no significant correlation among most of these metals, indicating different anthropogenic and natural sources. To assess ecotoxic potential of marine sediments, Numerical Sediment Quality Guidelines were also applied. The concentration of Pb in all the sediments except one was lower than the threshold effect concentration (TECs) showing that there are no harmful effects to marine life from Pb. On the other hand, the concentrations of Cr, Ni, and Zn exceeded TEC in three stations, indicating their potential risk. The degree of pollution in sediments for metals was assessed by calculating enrichment factor (EF) and pollution load index (PLI). The results indicated that sediments of Layari River Mouth Area, Fish Harbour, and KPT Boat Building Area are highly enriched with Cr and Zn (EF?>?5). Sediments of Layari River Outfall Zone were moderately enriched with Ni and Pb (EF?>?2). The pollution load index was found in the range of 0.98 to 1.34. Lower values of PLI (≤1) at most of sampling locations imply no appreciable input from anthropogenic sources. However, relatively higher PLI values (>1) at Layari River Mouth Area, Fish Harbour, and KPT Boat Building Area are attributed to increased human activity in the area.     

Integrating biophysical and socioeconomic information for prioritizing watersheds in a Kashmir Himalayan lake: a remote sensing and GIS approach

Dal Lake, a cradle of Kashmiri civilization has strong linkage with socioeconomics of the state of Jammu and Kashmir. During last few decades, anthropogenic pressures in Dal Lake Catchment have caused environmental deterioration impairing, inter-alia, sustained biotic communities and water quality. The present research was an integrated impact analysis of socioeconomic and biophysical processes at the watershed level on the current status of Dal Lake using multi-sensor and multi-temporal satellite data, simulation modelling together with field data verification. Thirteen watersheds (designated as ‘W1–W13’) were identified and investigated for land use/land cover change detection, quantification of erosion and sediment loads and socioeconomic analysis (total population, total households, literacy rate and economic development status). All the data for the respective watersheds was integrated into the GIS environment based upon multi-criteria analysis and knowledge-based weightage system was adopted for watershed prioritization based on its factors and after carefully observing the field situation. The land use/land cover change detection revealed significant changes with a uniform trend of decreased vegetation and increased impervious surface cover. Increased erosion and sediment loadings were recorded for the watersheds corresponding to their changing land systems, with bare and agriculture lands being the major contributors. The prioritization analysis revealed that W5?>?W2?>?W6?>?W8?>?W1 ranked highest in priority and W13?>?W3?>?W4?>?W11?>?W7 under medium priority. W12?>?W9?>?W10 belonged to low-priority category. The integration of the biophysical and the socioeconomic environment at the watershed level using modern geospatial tools would be of vital importance for the conservation and management strategies of Dal Lake ecosystem.     

Modelling mixing height from routinely measured surface and upper air meteorological data

A one‐dimensional model is developed for the estimation of hourly mixing height values from routinely measured upper air and surface meteorological data. A diagnostic technique is used in the model to calculate the convective and mechanically induced mixing height values under different atmospheric, and day and night‐time conditions. In the scheme, for the day‐time hours, the mixing height is determined as the larger of the convective and mechanically induced mixing height values. For the night‐time hours, only the mechanically induced mixing height values are considered. Three‐hourly mixing height values are modelled using once‐a‐day upper air temperature profile data (from radio‐sonde) and three‐hourly surface meteorological data. The spatial and temporal variation of mixing height are modelled in the Brisbane airshed and their relationship with the atmospheric stability, solar radiation and transport wind speed is developed.