Synthesis and characterization of Cu(II), Ni(II), and Zn(II) Schiff bases complexes resulted from the condensation of salicylaldehyde derivatives with o-amino phenol were discussed using elemental analysis (carbon, hydrogen, and nitrogen), molar conductance, magnetic measurements, mass spectra, and electronic spectra. The essential bands of infrared, 1HNMR, and UV-Vis spectra as well as thermogravimetric analysis corresponding to the active groups within the three ligands and their complexes were interpreted. The dehydration and decomposition processes of the [Cu(H2L1)(H2O)](OAc)2, [Ni(H2L1)(H2O)]SO4 · H2O, [Zn(H2L1)(H2O)]SO4 · H2O, [Cu(H2L2)(H2O)](OAc)2, [Ni(H2L2)(H2O)]SO4 · H2O, [Zn(H2L2)(H2O)]SO4 · 2H2O, [Cu(H2L3)(H2O)](OAc)2 · H2O, [Ni(H2L3)(H2O)]SO4 · 2H2O, [Zn(H2L3)(H2O)]SO4 complexes were studied thermodynamically using the integral method applying the Coats–Redfern and Horowitz–Metzger equations and the thermodynamic parameters were calculated. It was found from the elemental analysis and the thermal studies, that the ligand behaves as tridentate ligand forming chelates with 1 : 1 (metal : ligand) stoichiometrically. The molar conductance measurements of the complexes in dimethyl sulfoxide solvent indicate that the complexes have an electrolytic nature. The biological activities of the three ligands in comparison with metal(II) complexes were studied against different Gram positive and Gram negative bacteria. 相似文献
The transportation sector is a crucial driver of energy intensity and environmental degradation. Therefore, we aim to explore the nexus of transportation taxes, energy intensity, and CO2 emissions for the BICS economies. The econometric approaches, CS-ARDL and PMG-ARDL, have been employed to compute the estimates. The long-run estimates of the green transportation tax variable are negatively significant in both energy intensity and CO2 emissions models irrespective of the estimation technique. These findings imply that green transportation taxes help reduce energy intensity and CO2 emissions in BICS economies. Conversely, in the short-run, the effects of transportation taxes on energy intensity and CO2 emissions are mixed and inconclusive. Hence, transportation taxes are necessary to keep the polluters under control not only from the transport sector but also serve as a deterrent for other sectors as well.
● Six largely produced agricultural biomass wastes were pyrolyzed into biochars. ● Feedstock type significantly determined physiochemical properties of biochars. ● The biochars showed powerful adsorption capabilities to Plasticizer DEP. ● Giant reed biochar with higher DEP adsorption was a prominent sorbent. Plastic pollution as a global environmental issue has become a research hotspot, among which the removal of inherent plasticizer (e.g., phthalic acid esters, PAEs) received increasing attention. However, the effects of biochars derived from different feedstocks on the adsorption of PAEs are poorly understood. Thus, the characteristics of biochars derived from six largely produced biomass wastes in China at 400 °C, as well as their performance in adsorption of diethyl phthalate (DEP), one of frequently detected PAEs in aqueous environment, were investigated. The results indicated that the variation in feedstock type showed significant changes in the properties (e.g., porosity, specific surface area, surface functional groups) of biochars, which affected DEP adsorption and desorption. Pseudo-second order and Freundlich models fitted the adsorption data well, and adsorption mechanisms mainly included hydrophobic effect, followed by micropore filling, hydrogen bonding, and π-π EDA interactions. Adsorption thermodynamics revealed that the adsorption was a spontaneous and exothermic the adsorption capacities of DEP on these biochars slightly decreased with the increasing pH but increased with the increasing ionic strength. Among these biochars, the giant reed biochar with relatively higher DEP adsorption and low desorption exhibited the great efficiency for DEP removal as an environment-friendly sorbent. These results highlighted the significant roles of micropore filling and hydrogen bond in determining adsorption capacity of designed biochars prepared from selecting suitable agricultural straws and wetland plant waste to typical plasticizer. The findings are useful for producing designed biochars from different biomass wastes for plasticizer pollution control. 相似文献
Environmental Science and Pollution Research - Photocatalytic oxidation (PCO) using a TiO2 catalyst is an effective technique to remove gaseous volatile organic compounds (VOCs). Herein, a... 相似文献
Heavy metals in suburban soils pose both indirect and direct health risks. This study assessed the concentrations of Cr, Zn, Pb, and Cd in Jengka (Malaysia) suburban soil and estimated the human health risk. Health risk assessment (HRA) was utilized to assess non-cancer and cancer risks. The concentrations of heavy metals increased in the following order: Cd < Zn < Cr < Pb. The heavy metals were found to be divided into two components using principal component analysis (PCA), with PC1 comprising Pb and Cd and PC2 containing Zn and Cr. PC1 originates from anthropogenic sources, while PC2 is often from mixed anthropogenic and natural sources. Despite having the lowest mean concentration, Cd was enriched based on the geo-accumulation index (Igeo) and enrichment factor (EF). Average hazard index values were below the acceptable threshold (HI < 1) for dermal and inhalation pathways suggesting a low non-cancer risk. Jengka suburban soil had total lifetime cancer risk values slightly higher than the acceptable threshold (1 × 10−5). Skin contact was the most prominent contributing exposure pathway for both non-carcinogenic and carcinogenic risks. This study suggests that heavy metal bioactivity levels be used to make a plausible HRA of heavy metal pollution in suburban soils. 相似文献
In this study, we propose to develop a geostatistical computational framework to model the distribution of rat bite infestation of epidemic proportion in Peshawar valley, Pakistan. Two species Rattus norvegicus and Rattus rattus are suspected to spread the infestation. The framework combines strengths of maximum entropy algorithm and binomial kriging with logistic regression to spatially model the distribution of infestation and to determine the individual role of environmental predictors in modeling the distribution trends. Our results demonstrate the significance of a number of social and environmental factors in rat infestations such as (I) high human population density; (II) greater dispersal ability of rodents due to the availability of better connectivity routes such as roads, and (III) temperature and precipitation influencing rodent fecundity and life cycle. 相似文献
PAHs are formed during the incomplete combustion of organic substances containing carbon and hydrogen and are one of the first
atmospheric pollutants identified as carcinogens. Most of the PAH environmental burden is found in the soil (95%). Soil samples
collected from different roadsides were analyzed for seven polycyclic aromatic hydrocarbons (PAHs). The quantitative and qualitative
analysis was carried out by UV Spectrophotometer. The individual PAH value ranged from 0.1 to 18.0 mg/kg. Phenenthrene and
Pyrene were found to be the most abundant compounds. Vehicle emissions are the principal source of PAH in the Roadside soils.
The highest concentration was found at site S2 (Hasthtnagri Roadside) which shows the highest traffic density. 相似文献
The European eel’s swimbladder nematode, Anguillicola crassus, sampled from the Asi River (Orontes River) in Antakya (Hatay, Turkey) in May 2006 were analysed by Inductively Coupled Plasma-Atomic
Emission Spectrometry (ICP-AES) for their some heavy metal (Cd, Cr, Cu, Fe, Hg, Mn, Pb and Zn) levels. The metal concentrations
of the parasites were compared to different organs (swimbladder, liver, muscle and skin) of the fish hosts. The parasite contained
statistically highly significantly amounts of Fe (P < 0.05). The iron level of nematode was up to 25.52 times than the muscle of its host, Anguilla anguilla. However, bioconcentration of Cd, Cr, Cu, Hg, Mn, Pb, Zn were detected in the A. crassus and it contained no statistically differences with the other tissues of its host, the eel (P > 0.05). Furthermore, no significant differences were detected in the heavy metal accumulations between the parasitized and
un-parasitized fish tissues. The analysed metals (Cd, Cr, Cu, Fe, Mn, Pb and Zn) were found in fish muscle at mean concentrations
under the permissible limits proposed by FAO. 相似文献
Regarding various types of pollutant, waste management requires high attention. Environmental site selection study, prior
to landfill operation, and subsequently, monitoring and maintaining of the location, are of foremost points in landfill site
selection process. By means of these studies, it is possible to control the undesirable impacts caused by landfills. Study
ahead aims at examination of effectiveness of a new method called Monavari 95–2 in landfill site assessment. For this purpose,
two landfills Rasht and Andisheh, which are, respectively, located on humid and arid areas, were selected as case studies.
Then, the results obtained from both sites were compared with each other to find out the weaknesses and strengths of each
site. Compared with others similar methods, much more criteria (53 parameters) can be considered within this method, so the
results will be more calculable. According to this method, Rasht landfill (site H) is classified as unacceptable landfill
site i.e. there is an urgent need for a new suitable site for landfill, while Andishe Landfill (site D) is ranked as acceptable
landfill site but needs environmental management program to handle the existing weaknesses. 相似文献