scholarly journals A Simple and Effective Bio-adsorbent Generated from the Stems of Momordica charantia Plant for the Simultaneous Removal of Lead and Cadmium Ions from Wastewater

2021 ◽  
Vol 33 (11) ◽  
pp. 2633-2640
Author(s):  
Rajesh Babu Vabanagiri ◽  
Kunta Ravindhranath ◽  
Sneha Latha Pala ◽  
Wondwosen Kebede Biftu
Keyword(s):  
Industrial Effluents ◽  
Sorption Process ◽  
Momordica Charantia ◽  
Surface Barrier ◽  
Contaminated Water ◽  
Simultaneous Removal ◽  
Lead And Cadmium ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Mechanism Of Sorption

Sulphuric acid generated activated carbon from the stems of Momordica charantia (MCSAC) was identified to adsorb lead(II) and cadmium(II) ions from water. Extraction conditions were optimized. At pH: 6, both the ions can be simultaneous removed by 2.0 mg/L of MCSAC after an equilibration period of 90 min at room temperate (30 ± 2 ºC). The sorption capacities were observed to be 21.0 mg/g for Pb2+ and 18.9 mg/g for Cd2+. MCSAC was characterized by conventional methods and also by surface morphology assessing techniques such as XRD, FTIR and FESEM. The sorption mechanism was investigated by evaluating thermodynamic parameters and by adopting various kinetic and isothermal models. High ΔH values of 29.399 KJ/mol for Pb2+ and 33.222 KJ/mol for Cd2, indicated that the mechanism of sorption is ion exchange and /or complex formation between Pb2+/Cd2+ ions and surface functional groups present in MCSAC. Further, high positive ΔS values imply the presence of disorder at solid-liquid interface, favouring the metal ions to overcome the surface barrier and get adsorbed. The negative ΔG values indicates the spontaneity of sorption process. Spent MCSAC can be regenerated and reused for three cycles. The procedure developed using MCSAC as sorbent was successfully applied to treat real effluents samples collected from several industrial effluents. The novelty of the present investigation is that a simple biosorbent is developed for the effective simultaneous removal of highly toxic Pb2+ and Cd2+ from contaminated water.

scholarly journals Removal of Lead(II) Ions from Industrial Waste Water using Biomaterials of Terminalia ivorensis Plant and its Composite with Fe-Alginate Beads as Adsorbents

2020 ◽  
Vol 32 (12) ◽  
pp. 2977-2984
Author(s):  
Sayana Veerababu ◽  
Polavarapu Sreenitha ◽  
Tumma Prasanna Kumar Reddy ◽  
Kunta Ravindhranath
Keyword(s):  
Active Carbon ◽  
Industrial Effluents ◽  
Sorption Process ◽  
Alginate Beads ◽  
Liquid Interface ◽  
Surface Barrier ◽  
Ideal Condition ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Maximum Removal

Three effective adsorbents are developed for the removal of lead ions from industrial effluents based on stem powder of Terminalia ivorensis (TISP), its active carbon (TIAC) and a composite of Fe-alginatebeads doped with the active carbon (TIAC-beads). The beads are synthesized by crosslinking the Na-alginate with Fe3+ instead of conventional Ca2+, with an aim to improve its adsorptivity. The conditions for obtaining the uniform beads with good morphology are established. These sorbents are investigated for their adsoptivity for Pb2+ ions with respect to various extractions conditions and are optimized for the maximum removal of Pb2+. The sorption capacities are found to be: 34.0 mg/g for TISP, 39.0 mg/g for TIAC and 49.0 mg/g for TIAC-beads. The higher sorption of TIAC-beads may be due to the cumulative sorption nature of active carbon assisted by iron-alginate beads towards Pb2+. The optimum conditions are: for TISP: pH: 5, sorbent dosage: 2.0g/and, eqi. time: 120 min; for TIAC: pH: 7, sorbent dosage: 1.5 g/L; eqi. time: 90 min; and for TIAC-beads: pH: 6, sorbent dosage: 1.0 g/L and eqi. time: 60 min. Substantial removal of Pb2+ is noted in a range of pHs: 4 to 9 for TIAC-beads; 4 to 8 for TISP and 6 to 8 for TIAC. This permits the applicability of the sorbents in neutral as well as less acidic and basic solutions and it is a good feature as Pb2+ containing industrial effluents are inconsistent in their pHs. Three fold excess of co-ions marginally interfered. Thermodynamic studies reveal that the adsorption is endothermic and spontaneous. The high ΔH values, > 30.0 KJ/mol, emphasizes the chemical nature of binding between Pb2+ and surface functional groups of sorbent and is increasing in the order: TISP (32.385 KJ/mol) < TIAC (35.531 KJ/mol) < TIAC-beads (42.480 KJ/mol). This is supported by symmetrical humps with in the curves of pH vs. % removal. Positive ΔS values reflect disorder at the solid-liquid interface-an ideal condition for Pb2+ ions to cross the surface barrier existing at the solid/liquid interface, resulting in good adsorptivity. Negative ΔG values indicate the spontaneity of the sorption process. Spent TISP/TIAC/TIAC-beads can be regenerated and reused for 2 cycles for TISP, 3 cycles for TIAC and 3 cycles for TIAC-beads. The sorbents are successfully applied to remove Pb2+ form industrial effluents.

scholarly journals Adsorptive Removal of Copper Ions from Polluted Water Using Sorbents Derived from Cordia dichotoma, Albizia thompsonii and Polyalthia cerasoides Plants

2020 ◽  
Vol 32 (10) ◽  
pp. 2653-2659
Author(s):  
Tumma Prasanna Kumar Reddy ◽  
Sayana Veerababu ◽  
Malireddy Venkata Sai Mohan Reddy ◽  
Kunta Ravindhranath
Keyword(s):  
Activated Carbons ◽  
Copper Ions ◽  
Industrial Effluent ◽  
Industrial Effluents ◽  
Liquid Interface ◽  
Polluted Water ◽  
Physico Chemical ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Direct Applicability

Three different activated carbons as effective adsorbents were prepared by digesting the stems of Cordia dichotoma, Albizia thompsonii and Polyalthia cerasoides plants in conc. H2SO4 for Cu2+ removal from wastewater. The sorption natures of these sorbents are optimized with respect to various physico-chemical characteristics for the maximum Cu2+ removal using simulated waters. Cordia dichotoma (CDAC), Albizia thompsonii (ATAC) and Polyalthia cerasoides (PCAC) activated carbons show good sorption capacities of values: 97.0, 76.8 and 66.7 mg/g, respectively in a wide pH ranges. Unlike that of other two activated carbons, Cordia dichotoma activated carbon is effective even in acid conditions, indicting its direct applicability to Cu-based industrial effluents which are generally acidic in nature. Interference of two fold excess of co-ions is minimal. The established extraction conditions for the removal of more than 95.0% from 10 ppm Cu2+ solution at room temperature (303 K) using CDAC as sorbent are: pH: 3-9; time of equilibration: 1 h; sorbent dosage: 0.100 g/100 mL; with ATAC: pH: 6-9; time of equilibration: 1.5 h and sorbent dosage: 0.125 g/100 mL; and with PCAC: pH: 6-9; time of equilibration: 2.0 h and sorbent dosage 0.50 g/100 mL. Spent adsorbents can be regenerated and reused until four cycles with minimal loss of adoption capacities. Thermodynamic studies revealed that the sorption is spontaneous and endothermic in nature. Further, the ΔH value for CDAC is 30.156 KJ/mol; it indicates the strong chemisorption and may be through reduction to Cu+/Cu and/or complex formation between Cu2+ and functional groups of the adsorbent. The ΔH values of other two activated carbons, ATAC and PCAC, indicated that the sorption is mainly physical with strong inclination towards chemical nature. Positive ΔS values of all the three sorbents, emphasizes the disorder or randomness at the solid-liquid interface and hence favourable conditions for more penetration of Cu2+ into the surface layers of the adsorbent and hence, more removal of Cu2+ ions. The negative ΔG values indicate that the sorption forces are good enough to cross the potential barrier at the solid-liquid interface and hence the process is spontaneous. The prepared three activated carbons were also successfully applied to industrial effluent and polluted lake samples.

scholarly journals Utilization ofm-Phenylenediamine-Furfural Resin for Removal of Cu(II) from Aqueous Solution-A Thermodynamic Study

2010 ◽  
Vol 7 (3) ◽  
pp. 757-762
Author(s):  
Tariq S. Najim ◽  
Israa G. Zainal ◽  
Dina A. Ali
Keyword(s):  
Activation Energy ◽  
Aqueous Solution ◽  
Free Energy ◽  
Room Temperature ◽  
Adsorption Process ◽  
Sorption Process ◽  
The Other ◽  
Weak Values ◽  
Solid Liquid Interface ◽  
Solid Liquid

m-Phenylenediamine was condensed with furfural in absence of catalyst at room temperature. The producedm-phenylenediamine-furfural resin was used for the removal of Cu(II) from aqueous solution. The pH for the optimum removal of Cu(II) was 6. The negative values of Gibbs free energy at low concentration of Cu(II) (20, 30 ppm) indicative of the spontaneous adsorption process, while, at higher Cu(II) concentration (40,50 ppm) the positive and weak values of ∆G° indicate that the process is feasible but non spontaneous. The values of ∆H° were positive indicating that the sorption process is endothermic. On the other hand, the values of activation energy (Ea) were inconsistent with the values of ∆H° both are positive and lie in the range of physisorption. The entropy ∆S° of the process was positive indicative of the randomness of the Cu(II) ions at the solid / liquid interface. The values of sticking probability S* were less than one which indicate a preferable adsorption process and the mechanism is physisorption.

Atom-probe analysis of the solid-liquid interface

1995 ◽  
Vol 53 ◽  
pp. 676-677
Author(s):  
J.A. Panitz
Keyword(s):  
Molecular Level ◽  
Selective Adsorption ◽  
Electronic Devices ◽  
Atom Probe ◽  
Chemical Agent ◽  
Hostile Environment ◽  
Solid Interface ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Chemically Selective

The first few atomic layers of a solid can form a barrier between its interior and an often hostile environment. Although adsorption at the vacuum-solid interface has been studied in great detail, little is known about adsorption at the liquid-solid interface. Adsorption at a liquid-solid interface is of intrinsic interest, and is of technological importance because it provides a way to coat a surface with monolayer or multilayer structures. A pinhole free monolayer (with a reasonable dielectric constant) could lead to the development of nanoscale capacitors with unique characteristics and lithographic resists that surpass the resolution of their conventional counterparts. Chemically selective adsorption is of particular interest because it can be used to passivate a surface from external modification or change the wear and the lubrication properties of a surface to reflect new and useful properties. Immunochemical adsorption could be used to fabricate novel molecular electronic devices or to construct small, “smart”, unobtrusive sensors with the potential to detect a wide variety of preselected species at the molecular level. These might include a particular carcinogen in the environment, a specific type of explosive, a chemical agent, a virus, or even a tumor in the human body.

The role of (bio)surfactant sorption in promoting the bioavailability of nutrients localized at the solid-water interface

1999 ◽  
Vol 39 (7) ◽  
pp. 91-98 ◽  
Author(s):  
Ryan N. Jordan ◽  
Eric P. Nichols ◽  
Alfred B. Cunningham
Keyword(s):  
Mass Transfer ◽  
Cell Membrane ◽  
Substrate Concentration ◽  
Water Interface ◽  
Industrial Systems ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Surfactant Sorption

Bioavailability is herein defined as the accessibility of a substrate by a microorganism. Further, bioavailability is governed by (1) the substrate concentration that the cell membrane “sees,” (i.e., the “directly bioavailable” pool) as well as (2) the rate of mass transfer from potentially bioavailable (e.g., nonaqueous) phases to the directly bioavailable (e.g., aqueous) phase. Mechanisms by which sorbed (bio)surfactants influence these two processes are discussed. We propose the hypothesis that the sorption of (bio)surfactants at the solid-liquid interface is partially responsible for the increased bioavailability of surface-bound nutrients, and offer this as a basis for suggesting the development of engineered in-situ bioremediation technologies that take advantage of low (bio)surfactant concentrations. In addition, other industrial systems where bioavailability phenomena should be considered are addressed.

Observation of Femtosecond Acoustic Anomaly in a Solid Liquid Interface

2020 ◽  
Vol 124 (5) ◽  
pp. 2987-2993
Author(s):  
Chi-Kuang Sun ◽  
Yi-Ting Yao ◽  
Chih-Chiang Shen ◽  
Mu-Han Ho ◽  
Tien-Chang Lu ◽  
...  
Keyword(s):  
Liquid Interface ◽  
Acoustic Anomaly ◽  
Solid Liquid Interface ◽  
Solid Liquid
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