Studies on the Adsorption of Pb (II) and Zn (II) as Binary Mixtures from Industrial Effluents

The present work focuses on the adsorptive removal of mixtures of heavy-metal ions present in industrial effluents, using modified bio-sorbent prepared from Desmostachya bipinnata (MDB). The prepared biosorbent was characterized by SEM, DRFTIR, Elemental analyzer, XRD, Boem titration and point of zero charge, showing modificatios on the surface of the biosorbent. The adsorption behavior of two different metals, Pb (II) and Zn (II), indicated regular patterns of adsorption. Their adsorption behavior as binary mixtures was evaluated, which showed the interference of one metal ions with another, thereby reducing the adsorption capacities of both metal ions. Even though there is interference between two different metal ions, the modified biosorbent proved quite efficient in removing complex mixtures of heavy metal ions from industrial effulent

Studies on Functionalization of Apple Waste for Heavy Metal Treatment Abstract

The present investigation is to investigate the potential and effectiveness of two types of biosorbents as cation exchanger, functionalized with carboxylic acid and xanthated groups onto apple waste. Both the adsorbent materials exhibited highly selective behavior for heavy metal treatment and followed Langmuir adsorption isotherm model. The maximum adsorption capacity evaluated for iron, cadmium, zinc and lead onto them have shown their potential ability in the treatment of heavy metals from aqueous medium. Dominant sorption mechanisms are revealed to be ionexchange process

Adsorptive Removal of Methyl Red from Aqueous Solution onto Charred and Aminated Sugarcane Waste

Abstract: Adsorptive removal of Methyl Red (MR) from aqueous solution onto chemically modified charred sugarcane waste (CSW) and aminated sugarcane waste (ASW) has been investigated. The surface modification was characterized by FTIR, SEM, elemental analysis and Boehm titration. The effect of pH, contact time and MR concentrations were studied by batch equilibrium method. Maximum dye removal was observed at pH 2 onto CSW while that for ASW at pH 7. The dye can be quantitatively removed onto the surface of these adsorbents at a contact time of 3 h. Maximum adsorption capacity (qmax) for the CSW and ASW were found to be 125.0 mg/g and 142.85 mg/g, respectively. Adsorption kinetic data were tested using pseudo-first order, pseudo-second order and intra-particle diffusion models. Kinetic studies revealed that the adsorptive removal of the dye onto the adsorbents followed pseudo-second order kinetics model. The obtained results indicated an excellent alternative for the treatment of dye contaminated wastewater using such chemically modified sugarcane waste at low cost with better efficiency

Adsorption of Cd (II), Cu (II), and Zn (II) from Aqueous Solution onto Nitrogen-Functionalized Desmostachya bipinnata

A very simple means of nitrogen functional group grafting onto the backbone of Desmostachya bipinnata is investigated, which is a sacrificial herb in the south Asian region particular toHindu religion. This natural biomaterial is found to be very effective formetal binding, after treatment with hydrazine monohydrate. The present study explores a comparison of amination processes by considering several options.The maximum metal loading capacities for Cd, Cu, and Zn were found to be 76.80mg/g, 72.10mg/g, and 58.16mg/g, respectively.The kinetic evaluation indicated that the adsorption of Cd, Cu, and Zn onto the biomaterials followed the pseudo second-order rate equation

Biosorbents for Removing Hazardous Metals and Metalloids

Biosorbents for remediating aquatic environmental media polluted with hazardous heavy metals and metalloids such as Pb(II), Cr(VI), Sb(III and V), and As(III and V) were prepared from lignin waste, orange and apple juice residues, seaweed and persimmon and grape wastes using simple and cheap methods. A lignophenol gel such as lignocatechol gel was prepared by immobilizing the catechol functional groups onto lignin from sawdust, while lignosulfonate gel was prepared directly from waste liquor generated during pulp production. These gels effectively removed Pb(II). Orange and apple juice residues, which are rich in pectic acid, were easily converted using alkali (e.g., calcium hydroxide) into biosorbents that effectively removed Pb(II). These materials also effectively removed Sb(III and V) and As(III and V) when these were preloaded with multi-valent metal ions such as Zr(IV) and Fe(III). Similar biosorbents were prepared from seaweed waste, which is rich in alginic acid. Other biosorbents, which effectively removed Cr(VI), were prepared by simply treating persimmon and grape wastes with concentrated sulfuric acid

Acid-treated pomegranate peel; An efficient biosorbent for the excision of hexavalent chromium from wastewater

We studied the sequestration of hexavalent chromium Cr(VI) from an aqueous solution using chemically modified pomegranate peel (CPP) as an efficient bio-adsorbent. The synthesized material was characterized by X-ray diffraction spectroscopy (XRD), Fourier-transform infrared spectroscopy (FTIR), energy dispersive spectroscopy (EDS), and scanning electron microscopy (SEM). The impacts of parameters like solution pH, Cr(VI) concentration, contact time, and adsorbent dosage were investigated. Experimental results of the isotherm studies and adsorption kinetics were found agreeing to the Langmuir isotherm model and pseudo-second-order kinetics, respectively. The CPP showed appreciable Cr(VI) remediation capacity with a maximal loading capacity of 82.99 mg/g at pH 2.0, which was obtained in 180 min at room temperature. Thermodynamic studies revealed the biosorption process as spontaneous, feasible, and thermodynamically favorable. The spent adsorbent was eventually regenerated and reused, and the safe disposal of Cr(VI) was ensured. The study revealed that the CPP can be effectively employed as an affordable sorbent for the excision of Cr(VI) from water

Agro-Waste Derived Biomass Impregnated with TiO2 as a Potential Adsorbent for Removal of As(III) from Water

A novel type of adsorbent, TiO2 impregnated pomegranate peels (PP@TiO2) was successfully synthesized and its efficacy was investigated based on the removal of As(III) from water. The adsorbent was characterized using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectrometer (EDS), X-ray Diffraction (XRD) analysis, and Fourier Transform Infrared (FTIR) Spectroscopy, to evaluate its morphology, elemental analysis, crystallinity, and functional groups, respectively. Batch experiments were conducted on PP@TiO2 for As(III) adsorption to assess the adsorption isotherm, effect of pH, and adsorption kinetics. Characterization data suggested that TiO2 was successfully impregnated on the biomass substrate. The equilibrium data better fitted to the Langmuir isotherm model having a maximum adsorption capacity of 76.92 mg/g and better distribution coefficients (KD) in the order of ~103 mL/g. The highest percentage of adsorption was found at neutral pH. The adsorption kinetics followed the pseudo-2nd-order model. X-ray Photoelectron Spectroscopy (XPS) of the adsorption product exhibited that arsenic was present as As(III) and partially oxidized to As(V). PP@TiO2 can work effectively in the presence of coexisting anions and could be regenerated and reused. Overall, these findings suggested that the as-prepared PP@TiO2 could provide a better and efficient alternative for the synergistic removal of As(III) from water