Sorption of Cu(II) ions by nano‐scale zero valent iron supported on rubber seed shell

This study focused on synthesising nano‐scale zero valent iron (NZVI) impregnated on a low‐cost agro‐waste material, rubber seed shell (RSS), by borohydride reduction method. The characterisation studies of NZVI‐RSS were performed by Fourier transform infrared spectroscopy, scanning electron microscopy and X‐ray diffraction. The adsorption execution of NZVI‐RSS for Cu(II) ions evacuation from synthetic wastewater was explored by batch studies. The optimum condition for the present adsorption system is as follows: Cu(II) ion concentration = 25 mg/l; solution pH = 6.0; contact time = 30 min; NZVI‐RSS dose = 3 g/l; temperature = 30°C. The sorption data were best portrayed by pseudo‐first‐order and Freundlich models. The outcomes demonstrated the multilayer sorption of Cu(II) ions by NZVI‐RSS. The Langmuir capacity was observed as 48.18 mg/g. Thermodynamic parameters, ΔG °, ΔH ° and ΔS ° were ascertained, and it was watched that the adsorption system was unconstrained and exothermic. The sticking probability for Cu(II) ions by NZVI‐RSS was found to be high at lower temperature. At long last, the research inquire about reasoned that NZVI‐RSS has demonstrated unrivalled adsorption capacity. Also NZVI‐RSS is thought to be really green and financially amicable support for wastewater treatment.Inspec keywords: adsorption, copper, X‐ray diffraction, scanning electron microscopy, wastewater treatment, Fourier transform infrared spectroscopyOther keywords: nano‐scale zero valent iron, rubber seed shell, copper ions, borohydride reduction method, NZVI‐RSS, Fourier transform infrared spectroscopy, scanning electron microscopy, X‐ray diffraction, adsorption execution, synthetic wastewater, Langmuir capacity, Freundlich models, adsorption system, wastewater treatment, adsorption capacity, Cu     

Review on nanoadsorbents: a solution for heavy metal removal from wastewater

Elimination of heavy metals from contaminated streams is of prime concern due to their ability to cause toxic chaos with the metabolism of flora and fauna alike. Use of advanced nano‐engineered technologies such as the innovative combination of surface chemistry, chemical engineering fundamentals and nanotechnology opens up particularly attractive horizons towards treatment of heavy metal contaminated water resources. The obtained product of surface engineered nanoadsorbent produced has successfully proven to show rapid adsorption rate and superior sorption efficiency towards the removal of a wide range of defiant heavy metal contaminants in wastewater. The use of these materials in water treatment results in markedly improved performance features like large surface area, good volumetric potential, extra shelf‐lifetime, less mechanical stress, stability under operational conditions with excellent sorption behaviour, no secondary pollution, strong chelating capabilities and they are easy to recover and reuse. This review intends to serve as a one‐stop‐reference by bringing together all the recent research works on nanoparticles synthesis and its advantages as adsorbents in the treatment of heavy metal polluted wastewater that have so far been undertaken, thereby providing researchers with a deep insight and bridging the gap between past, present and future of the elegant nanosorbents.Inspec keywords: wastewater treatment, nanotechnology, adsorption, contaminationOther keywords: heavy metal removal, wastewater, contaminated streams, nanoengineered technology, surface chemistry, chemical engineering fundamentals, nanotechnology, heavy metal contaminated water resources, surface‐engineered nanoadsorbent, rapid adsorption rate, sorption efficiency, heavy metal contaminants, water treatment, surface area, volumetric potential, shelf‐lifetime, mechanical stress, stability, sorption behaviour, chelating capabilities     

Removal of toxic zinc from water/wastewater using eucalyptus seeds activated carbon: non‐linear regression analysis

In the present study, a novel activated carbon was prepared from low‐cost eucalyptus seeds, which was utilised for the effectively removal of toxic zinc from the water/wastewater. The prepared adsorbent was studied by Fourier transform infrared spectroscopy and scanning electron microscopic characterisation studies. Adsorption process was experimentally performed for optimising the influencing factors such as adsorbent dosage, solution pH, contact time, initial zinc concentration, and temperature for the maximum removal of zinc from aqueous solution. Adsorption isotherm of zinc removal was ensued Freundlich model, and the kinetic model ensued pseudo‐second order model. Langmuir monolayer adsorption capacity of the adsorbent for zinc removal was evaluated as 80.37 mg/g. The results of the thermodynamic studies suggested that the adsorption process was exothermic, thermodynamically feasible and impulsive process. Finally, a batch adsorber was planned to remove zinc from known volume and known concentration of wastewater using best obeyed model such as Freundlich. The experimental details showed the newly prepared material can be effectively utilised as a cheap material for the adsorption of toxic metal ions from the contaminated water.Inspec keywords: wastewater treatment, activated carbon, zinc, toxicology, regression analysis, Fourier transform infrared spectra, scanning electron microscopy, adsorption, pH, reaction kinetics, monolayers, thermodynamics, contaminationOther keywords: Zn, toxic metal ion adsorption, contaminated water, batch adsorber, exothermic process, thermodynamic process, Langmuir monolayer adsorption capacity, pseudosecond‐order model, kinetic model, Freundlich model, adsorption isotherm, aqueous solution, temperature value, initial zinc concentration, contact time, pH value, adsorbent dosage, scanning electron microscopic characterisation, Fourier transform infrared spectroscopy, nonlinear regression analysis, eucalyptus seed activated carbon, wastewater, toxic zinc removal     

Preparation of a novel zwitterionic graphene oxide-based adsorbent to remove of heavy metal ions from water: Modeling and comparative studies

A novel zwitterionic graphene oxide-based adsorbent was first synthesized in a multistep procedure including the successive grafting of bis(2-pyridylmethyl)amino groups (BPED) and 1,3-propanesultone (PS) onto graphene oxide (GO) sheets. Then, the as-prepared materials were used as adsorbent for the removal of metal ions from aqueous solutions. The influence of solution pH, contact time, metal ion concentration, and temperature onto the adsorption capacity of the zwitterionic GO-BPED-PS adsorbent was investigated and compared with the GO-BPED adsorbent. In particular, it was shown that the maximum adsorption capacities of the GO-BPED-PS adsorbent were as high as 4.174 ± 0.098 mmol.g^?1 for the Ni(II) ions and 3.902 ± 0.092 mmol.g^?1 for the Co(II) ions under optimal experimental conditions (metal ion concentration = 250 mg.L^?1, pH = 7 and T = 293 K). In addition, the adsorption behaviors of Ni(II) and Co(II) ions onto both the GO-BPED and GO-BPED-PS adsorbents fitted well with a pseudo-second-order kinetic model and a Jossens isotherm model. Moreover, adsorption thermodynamics of Ni(II) and Co(II) ions have been studied at various temperatures and confirmed the exothermic adsorption nature of the adsorption process onto the GO-BPED-PS adsorbent. Furthermore, the zwitterionic GO-BPED-PS adsorbent retained good adsorption properties after recycling 18 times which is much better than the conventional adsorbents.