Removal of Cu(II),Pb(II),Mg(II),and Fe(II) by Adsorption onto Alginate/Nanocellulose Beads as Bio-Sorbent

Alginate blended with cellulose nanocrystals(CNC),cellulose nanofibers(CNF),and tri-carboxylate cellulose nanofibers(TPC-CNF)prepared and encapsulated in the form of microcapsules(bio-polymeric beads).The cellulosic nanomaterials that used in this study were investigated as nanomaterials for wastewater treatment applications.Batch experiments were performed to study the removal of copper,lead,magnesium,and iron from aqueous solutions by the prepared beads.The effects of the sorbent dosage and the modified polymers on the removing efficiency of the metal cations were examined.Atomic absorption was used to measure the metal ions concentrations.The modified bio-polymeric beads(Alg-CNF,Alg-CNC,and Alg-TPC-CNF)exhibited high-efficiency towards removing of the metal cations;Cu^(2+),Pb^(2+),Mg^(2+),and Fe^(2+).The Alg-TPC-CNF composite was exhibited excellent removing efficiency which around 95%for Pb,92%for Cu,43%for Fe and 54%for Mg.These outcomes affirm that the utilization of nanomaterials giving higher adsorption capacities contrasted with similar material in its micro or macrostructure form.

The use of carbon nanomaterials in membrane distillation membranes:a review

Membrane distillation(MD)is a thermal-based separation technique with the potential to treat a wide range of water types for various applications and industries.Certain challenges remain however,which prevent it from becoming commercially widespread including moderate permeate flux,decline in separation performance over time due to pore wetting and high thermal energy requirements.Nevertheless,its attractive characteristics such as high rejection(ca.100%)of nonvolatile species,its ability to treat highly saline solutions under low operating pressures(typically atmospheric)as well as its ability to operate at low temperatures,enabling waste-heat integration,continue to drive research interests globally.Of particular interest is the class of carbon-based nanomaterials which includes graphene and carbon nanotubes,whose wide range of properties have been exploited in an attempt to overcome the technical challenges that MD faces.These low dimensional materials exhibit properties such as high specific surface area,high strength,tuneable hydrophobicity,enhanced vapour transport,high thermal and electrical conductivity and others.Their use in MD has resulted in improved membrane performance characteristics like increased permeability and reduced fouling propensity.They have also enabled novel membrane capabilities such as in-situ fouling detection and localised heat generation.In this review we provide a brief introduction to MD and describe key membrane characteristics and fabrication methods.We then give an account of the various uses of carbon nanomaterials for MD applications,focussing on polymeric membrane systems.Future research directions based on the findings are also suggested.

Chlorine as an integrated approach for environmental health and hygiene:A case study on evaluation of the performance of waste stabilization ponds located at 11 governorates in Egypt

The current study summarizes the current status of wastewater stabilization ponds(WSPs)treatment plants that have already been built in 11 governorates throughout Egypt.Moreover,this study aims to determine the most appropriate chlorine dose for waste stabilization ponds(WSPs)effluents to ensure the treated effluents are suitable for reuse in unrestricted irrigation and to comply with the current legislation on direct discharge onto water bodies.According to the findings,the chlorine doses used as a disinfectant in the treated effluents of the majority of WSP treatment plants ranged from 3 to 13 mg/L.Meanwhile,two of the WSPs treatment plants effluents,the Qus WSPs treatment plant in Qena governorate and the Al Zarabii WSPs treatment plant in Asyut governorate used high chlorine doses reached to 17 and 19 mg/L,respectively.This is due to the fact that both the Qus and Al Zarabii WSPs treatment plants have a high organic load,which necessitated the use of more chlorine to achieve the optimum chlorine dose at 13 mg/L for Qus and 11mg/L for Al Zarabii.The findings demonstrated that chlorine has a powerful effect in completely removing bacteria.Furthermore,in most chlorine-treated wastewater final effluents,as the chlorine doses increased,the chlorophyll-a reading decreased.The amount of trihalomethanes(THMs)produced as disinfectant byproduct was measured.The results proved that the water can be used in unrestricted irrigation,and after adding chlorine,it can be dumped on water bodies without health risks.