Kinetic adsorption of application of carbon nanotubes for Pb（II） removal from aqueous solution

The capability of carbon nanotubes (CNTs) to adsorb lead (Pb) in aqueous solution was investigated. Batch mode adsorption experiment was conducted to determine the effects of pH, agitation speed, CNTs dosage and contact time. The removal of Pb(II) was reach to maximum value 85% or 83% at pH 5 or 40 mg/L of CNTs, respectively. Higher correlation coefficients from Langmuir isotherm model indicates the strong adsorptions of Pb(II) on the surface of CNTs (adsorption capacity Xm = 102.04 mg/g). From this study, the results indicates that the highest percentage removal of Pb (96.03%) can be achieved at pH 5, 40 mg/L of CNTs, contact time 80 min, and agitation speed 50 r/min.     

Integration of biogas systems into a carbon zero and hydrogen economy: a review

Environmental Chemistry Letters - The Ukraine conflict has put critical pressure on gas supplies and increased the price of fertilisers. As a consequence, biogas has gained remarkable attention as...     

Inhibition and recovery of serum,liver and brain acetylcholinesterase activities in rats exposed to new groups of O-ethyl phosphoramidates and benzo-1,3,2-dioxaphospholenes

Searching for new organophosphorus compounds with minimum effects on acetylcholinesterase of non-target organism especially mammals has gained an increased attention in the public concern. In this effort, the effects of some recently introduced O-ethyl phosphoramidates and benzo-1,3,2-dioxaphospholenes on rat acetylcholinesterase in different tissues have been evaluated in vivo and compared with the effects of fenitrothion, a commercial pesticide with reported moderate toxicity to mammals. The tested compounds were introduced orally in a single dose of 85?mg/kg body weight. Results indicated that the tested phosphoramidates lowered the enzyme activity to 54–69, 36–71 and 70–76% of its normal activity in serum, liver and brain, respectively. Meanwhile, the enzyme activity was depressed by fenitrothion to 11, 2 and 11% in the mentioned organs respectively. The lower anticholinesterase activity of the examined phosphoramidates than that of fenitrothion was attributed to their low hydrophobicity and low electrophilicity of their phosphorus atom, which reduces their interaction with the enzyme active site.     

Polyaniline films for efficient removal of aromatic acids from water

Adsorbents in the form of powders are commonly used to filtrate organic compounds in waters. However, this technique requires the separation of the solid phase from the solution after adsorption experiments. Here we propose the use of films as adsorbents. We synthesized polyaniline films by chemical oxidative polymerization of aniline on red ceramic brick. This film was tested to remove trimellitic, hemimellitic and pyromellitic acids as model molecules of the biodegradation of aquatic humic substances. We evaluated the effect of pH, contact time and initial concentration. Our results show that optimal adsorption conditions required 45 min of solid/liquid contact at pH 7 and an initial concentration of 20 mg/l. The maximum adsorption capacities for hemimellitic, trimellitic and pyromellitic acids are 154.83 for hemimellitic acid, 161.88 for trimellitic acid and 175.26 mg/g for pyromellitic acid. The adsorption efficiency of the polyaniline film decreased only by 13 % after four cycles. Overall, we conclude that polyaniline films are promising separable adsorbents compared to conventional adsorbents for removal of aromatic polycarboxylic acids from water.     

Geo-environmental hazards assessment of the north western Gulf of Suez,Egypt

The aim of the present study is to assess the present geo-environmental hazards, both flash flooding and seismic activity in the western part of Gulf of Suez. Assessment includes the analysis of satellite images, topographical, geological and other ancillary geological data using GIS technology. GIS data integration and analysis, including morphometric, local seismic activity and structural data analysis indicated that the area is under threat from two types of geo-hazards. Morphometric analysis strongly supported the high probability of flash flooding in different sites within the study area. The structural lineaments, extracted from an enhanced ETM+7 image, showed that the majority of seismic activity is related to segments of the fault system of the Gulf of Suez and the Gulf of Aqaba. The seismic activity hazard was taken into consideration through the identification of the sources of events. Seismic activity in the study area markedly increases from north to south. The distribution of the seismic activity pattern and data analysis for the study area clearly exhibits the urgent need for an assessment and rehabilitation program to mitigate geo-hazard along the existing structures.