Environmental and Ecological Statistics - The paper proposes a new perspective in the environmental and resource economics literature by examining innovation (measured by R&D expenditures),... 相似文献
Pakistan is an agricultural country and due to the shortage of clean water, most of the irrigated area (32,500 ha) of Pakistan was supplied with wastewater (0.876?×?109 m3/year). Concentrations of heavy metals in radish (Raphanus sativus) and turnip (Brassica rapa) taken from vegetable fields in Sargodha, Pakistan, were measured. Untreated wastewater was used persistently for a long time to irrigate these vegetable fields. A control site was selected that had a history of fresh groundwater irrigation. Mean metal concentrations were found for irrigation water, soil, and vegetables. In irrigation water, concentrations of Mo and Pb at three sites and Se at sites II and III were higher than the recommended limits. In vegetables, concentrations of Mo and Pb were above the maximum permissible limits. High bioconcentration factor was observed for Zn (12.61 in R. sativus and 11.72 in B. rapa) at site I and high pollution load index was found for Pb (3.89 in R. sativus and 3.87 in B. rapa) at site II. The differences in metal concentrations found in samples depended upon different soil nature and assimilation capacities of vegetables at different sites which in turn depended upon different environmental cues. The entrance of metal and metalloids to human body may happen through different pathways; however, the food chain is the chief route through which metals are transferred from vegetables to individuals. Health risk index observed for metals, (Mo, As, Ni, Cu, and Pb) higher than 1 indicated high risk through consumption of these vegetables at three sites.
Environmental Science and Pollution Research - This study was designed to investigate the impact of meteorological indicators (temperature, rainfall, and humidity) on total COVID-19 cases in... 相似文献
Environmental Science and Pollution Research - In this study, Moringa seed powder (MSP) was pyrolyzed at 450 °C to synthesize Moringa seed powder biochar (MSPB) and treated with phosphoric... 相似文献
A highly sensitive enzyme immunoassay is described for the detection of atrazine residues in water. Atrazine derivative was conjugated to Bovine Serum Albumin (BSA) to obtain an immunizing antigen and to Horseradish Peroxidase enzyme (POD) to obtain a marker for immunoassay. The formation of these conjugations was confirmed by UV spectroscopy as well as by gel-electrophoresis. Polyclonal antibodies were raised in rabbits by immunization with an atrazine-BSA conjugate containing 29 atrazine residues per BSA molecule. An ELISA on microtitration plates was optimized with peroxidase-atrazine conjugate. The middle of the test (50% B/Bo) was found to be at 90 ng/l, which is well below the maximum concentration permitted by the EC guidelines for drinking water. Detection limits for atrazine of about 1 ng/l could be reached. The assay did not require concentration or cleanup steps for drinking or ground water samples. Validation experiments showed good accuracy and precision. No cross-reactivities were shown by other s-triazines like terbutryn, ametryn, terbuthylazine, des-isopropylatrazine, and de-ethylatrazine except hydroxyatrazine. The latter was present at very low levels that can be calibrated/standardized before analysis or it may be considered as leftover residues of atrazine. Based on these results, it is suggested that this test can be applied to obtain fairly accurate results for atrazine concentration in water samples from different sources. 相似文献
We assessed the impact of urban effluents on the concentrations of selected minerals (Cd, Cr, Cu, Fe, Pb, Zn, Mn, Ni, and Hg) in river Ravi before and after its passage through Lahore city. Water and sediment samples were collected from three lowly to highly polluted downstream sites (Shahdera (B), Sunder (C), and Balloki (D)) alongside the least polluted upstream site (Siphon (A)) during high and low river flow seasons. All the mineral concentrations increased up to site C but stabilized at site D, showing some recovery as compared to the third sampling site. The trend of mean mineral concentration was significantly higher during the low than the high flow season at all the sites. The mean Hg concentrations approached 0.14 and 0.12 mg/l at site A which increased (%) up to 107 and 25 % at site B, 1,700 and 1,317 % at site C, and 1,185 and 1,177 % at site D during low and high river flows, respectively. All mineral concentrations were much higher in the sediment than the water samples. Mean Cd (917 %), Cr (461 %), Cu (300 %), Fe (254 %), Pb (179 %), Zn (170 %), Mn (723 %), Ni (853 %), and Hg (1,699 %) concentrations were higher in riverbed sediments sampled from site C in comparison with the sample collected at site A during low flow season. The domestic and industrial discharges from Lahore city have created undesirable water qualities during the low river flow season. As majority of the mineral levels in the river Ravi were higher than the permissible and safe levels, this is of immediate concern for riverine fish consumers and the users of water for recreation and even irrigation. The use of these waters may pose health risks, and therefore, urgent intervention strategies are needed to minimize river water pollution and its impact on fish-consuming communities of this study area and beyond. 相似文献
In this article, we study the use of thermally reduced graphene (TRG) for oil spill cleanup. TRG was synthesized by thermal exfoliation of graphite oxide and characterized by X-ray diffusion, Raman spectroscopy, SEM, TEM, elemental analysis, and Brunauer–Emmett–Teller (BET) surface area measurement. Various aspects of the sorption process have been studied including the sorption capacity, the recovery of the adsorbed oil, and the recyclability of TRG. Our results shows that TRG has a higher sorption capacity than any other carbon-based sorbents, with sorption capacity as high as 131 g of oil per gram TRG. With recovery of the sorbed oil via filtration and reuse of TRG for up to six cycles, 1 g of TRG collectively removes approximately 300 g of crude oil. Moreover, the effects of TRG bulk density, pore volume, and carbon/oxygen ratio and the oil viscosity on the sorption process are also discussed. 相似文献