Role of Purged Air On Synthesis of Mesoporous NiO/C Composite And Its Application On Waste Water Treatment

Abstract Two different methods were employed to synthesis NiO/C composite from agricultural waste. The mesoporous composite was successfully synthesized via a novel precipitation method in the presence of dissolved gases. The morphology of the composites were differentiated by characterisation techniques such asx-ray Diffraction (XRD), the point of zero charge (pHpzc), field emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FTIR), energy dispersive x-ray analysis (EDAX) and vibrating sample magnetometer (VSM). Then, the mechanism of synthesis was elucidated using the above experimental characterisation data. FESEM and EDAX report of Ni(OH)2-carbon composite clearly showed the role of dissolved gases on synthesis. Both the composites were subjected as the adsorbent to eliminate/remove the toxic Pb(II) ions from the wastewater. Batch adsorption experiments were carried out to compare the Pb(II) ions removal capability of both the composite materials. The parameters such as the effect of pH, the dosage of the adsorbents and initial concentration were studied. At the optimized conditions, isotherm studies for each of the adsorbents were also carried out. The isotherm results revealed that the maximum removal capacity qe (mg/g) was 30.78 for PJNC and 43.48 for PJGNC. The VSM analysis confirmed that both the adsorbents were soft magnetic materials. Hence, they could be competently separated from salted/treated water using the magnetic field.

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Kinetic and thermodynamic studies of polyvinyl chloride composite of manganese oxide nanosheets for the efficient removal of dye from water

Water Science & Technology ◽

10.2166/wst.2021.282 ◽

2021 ◽

Author(s):

Tooba Saeed ◽

Abdul Naeem ◽

Tahira Mahmood ◽

Afsar Khan ◽

Zahoor Ahmad ◽

...

Keyword(s):

Manganese Oxide ◽

Surface Area ◽

Polyvinyl Chloride ◽

Point Of Zero Charge ◽

Batch Adsorption ◽

X Ray Diffraction ◽

Efficient Removal ◽

X Ray ◽

Removal Capacity ◽

The Fourier Transform

Abstract Manganese oxide nanosheets and manganese oxide composite with polyvinyl chloride (MnO2-PVC) were synthesized by the oxidation method for the efficient removal of congo red (CR). The Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive X-ray, surface area, point of zero charge and thermogravimetric analysis were performed to verify the newly synthesized adsorbents. After functionalizing the surface of MnO2 nanosheets with PVC, the PZC and SA were amplified from 4.10 and 214 m2g−1 to 5.01 and 226 m2g−1 respectively. The batch adsorption results showed that the removal capacity of CR on both the adsorbents decreased with the increase of pH and time, but increased with the increase of adsorbent dosage. However, due to the high stability, porosity and greater surface area, the PVC composite of MnO 2 was found to exhibit 15 times greater CR removal efficiency than its parent MnO 2 . Furthermore, the thermodynamic parameters specified that CR adsorption onto both the adsorbents was exothermic, spontaneous and film diffusion accompanied by the intraparticle diffusion is the rate controlling step. These results validate that MnO 2 composite with PVC is a useful, eco-friendly, competent candidate for dye removal from wastewater.

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Synthesis of Modified Spent Tea for Aspirin Adsorption in Aqueous Solution

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.a3502.098319 ◽

2019 ◽

Vol 8 (3) ◽

pp. 531-534

Keyword(s):

Aqueous Solution ◽

Contact Time ◽

Acid Treatment ◽

Agricultural Waste ◽

Point Of Zero Charge ◽

Solution Temperature ◽

Batch Adsorption ◽

Optimal Conditions ◽

Solution Ph ◽

Adsorption Mechanisms

This present study focuses on the synthesis of a new modified eco-friendly adsorbent, spent tea (ST, discarded Camellia sinensis leaves), and its application in the adsorption of Aspirin from aqueous solution by batch adsorption technique. This is an effort in shifting towards new substitutes that are both inexpensive and highly efficient, such as agricultural waste materials as an alternative of the commonly used adsorbent material, activated carbon. The ST will first undergo an acid treatment using phosphoric acid, and subsequently modified with Polyethyleneimine (PEI) using Glutaraldehyde (GA) as the cross-linker. Aspirin removal efficiency was compared between the untreated spent tea (ST) and new PEI modified acid treated spent tea (TA-PEI). Effects of ratio of acid treated spent tea (TA) and PEI (1:1, 1:2,1:3, 2:1,3:1), and GA concentration (0,0.5,1.0,2.0,3.0, and 4.0 v/v%) were investigated. The optimal conditions for the synthesis of the modified adsorbent, TA-PEI are TA: PEI ratio of 1:2, and 0.5(v/v %) of GA. Afterwards, the untreated ST and TA-PEI were tested to determine the effect of contact time on Aspirin adsorption. It was found that TA-PEI shows great removal effectiveness - up to 64.70% before reaching equilibrium after 30min of contact time. Nevertheless, ST only shows removal of 1% and after 15min, there is no appreciable adsorption. These results suggested that TA-PEI has high potential to be used as an effective adsorbent for Aspirin removal. In the future, TA-PEI will undergo further research to investigate the effects of different adsorbent dosage, solution pH, initial concentration, solution temperature, and contact time. Several analysis (FTIR, SEM, CHNS, BET and point of zero charge) has to be done as well to get a better understanding of its properties and the adsorption mechanisms

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Application of response surface methodology for uranium(VI) adsorption using hydroxyapatite prepared from eggshells waste material: study of influencing factors and mechanism

Water Science & Technology ◽

10.2166/wst.2021.022 ◽

2021 ◽

Author(s):

Safir Ouassel ◽

Salah Chegrouche ◽

Djamel Nibou ◽

Redouane Melikchi ◽

Abderahmane Aknoun ◽

...

Keyword(s):

Aqueous Solutions ◽

Low Cost ◽

Point Of Zero Charge ◽

Precipitation Method ◽

Type Model ◽

Batch Adsorption ◽

X Ray Diffraction ◽

Raman Spectrometry ◽

Uranyl Carbonate ◽

Pseudo Second Order

Abstract Hydroxyapatite (HAp) was synthesized from biowaste hen eggshells by wet precipitation method in which calcium hydroxide and phosphoric acid were used as precursors. The effectiveness of uranium(VI) adsorption onto HAp was investigated by batch adsorption experiments from aqueous solutions. The obtained HAp powder was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectrometry, point of zero charge and Scanning electron microscope. The factors and levels used during the experiments were pH (2–5), adsorbent mass (0.01–0.05 g), and initial U(VI) concentration (100–310 mg L−1). A Box–Behnken design combined with analysis of variance was used to interpret the main effect influencing the adsorption. The results showed that pH was the most significant parameter affecting U(VI). The kinetic data correlates well with the pseudo-second-order model. The adsorption isotherms fitted the Langmuir-1 type model with the qmax = 175.22 mg g−1 at 25 °C. The calculated value of the mean free energy indicates the chemisorption process. Under optimal conditions, the uranium effluent derived from the precipitation of ammonium uranyl carbonate removal performance of 98% was achieved. This study proved that HAp prepared from eggshell was an ecofriendly and low-cost adsorbent and was very effective for the adsorption of U(VI) from aqueous solutions.

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Sewage sludge as a precursor of adsorbents/catalysts for environmental applications

Water Practice & Technology ◽

10.2166/wpt.2007.019 ◽

2007 ◽

Vol 2 (1) ◽

Author(s):

A. Ros ◽

C. Canals-Batlle ◽

M.A. Lillo-Ródenas ◽

E. Fuente ◽

M. A. Montes-Morán ◽

...

Keyword(s):

Sewage Sludge ◽

Room Temperature ◽

Waste Water Treatment ◽

Textural Properties ◽

Active Species ◽

Elemental Sulphur ◽

Gaseous Emissions ◽

Removal Experiments ◽

Catalytically Active

This paper focuses on the valorisation of solid residues obtained from the thermal treatment of sewage sludge. In particular, sewage sludge samples were collected from two waste water treatment plants (WWTPs) with different sludge line basic operations. After drying, sludges were heated up to 700 °C in appropriate ovens under diluted air (gasification) and inert (pyrolysis) atmospheres. The solids obtained, as well as the dried (raw) sludges, were characterised to determine their textural properties and chemical composition, including the speciation of their inorganic fraction. All the materials under study were employed as adsorbents/catalysts in H2S removal experiments at room temperature. It was found that, depending on the particular sludge characteristics, outstanding results can be achieved both in terms of retention capacities and selectivity. Some of the solids outperform commercially available sorbents specially designed for gaseous emissions control. In these adsorbents/catalysts, H2S is selectively oxidised to elemental sulphur most likely due to the presence of inorganic, catalytically active species. The role of the carbon-enriched part on these solids is also remarked.

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Investigating the Feasibility of Mefenamic Acid Nanosuspension for Pediatric Delivery: Preparation, Characterization, and Role of Excipients

Processes ◽

10.3390/pr9040574 ◽

2021 ◽

Vol 9 (4) ◽

pp. 574

Author(s):

Nikhat Perween ◽

Sultan Alshehri ◽

T. S. Easwari ◽

Vivek Verma ◽

Md. Faiyazuddin ◽

...

Keyword(s):

Particle Size ◽

Mefenamic Acid ◽

Hydroxypropyl Methylcellulose ◽

Sodium Dodecyl ◽

Aqueous Solubility ◽

Oral Route ◽

Precipitation Method ◽

Antisolvent Precipitation

Molecules with poor aqueous solubility are difficult to formulate using conventional approaches and are associated with many formulation delivery issues. To overcome these obstacles, nanosuspension technology can be one of the promising approaches. Hence, in this study, the feasibility of mefenamic acid (MA) oral nanosuspension was investigated for pediatric delivery by studying the role of excipients and optimizing the techniques. Nanosuspensions of MA were prepared by adopting an antisolvent precipitation method, followed by ultrasonication with varying concentrations of polymers, surfactants, and microfluidics. The prepared nanosuspensions were evaluated for particle size, morphology, and rheological measures. Hydroxypropyl methylcellulose (HPMC) with varying concentrations and different stabilizers including Tween® 80 and sodium dodecyl sulfate (SLS) were used to restrain the particle size growth of the developed nanosuspension. The optimized nanosuspension formula was stable for more than 3 weeks and showed a reduced particle size of 510 nm with a polydispersity index of 0.329. It was observed that the type and ratio of polymer stabilizers were responsive on the particle contour and dimension and stability. We have developed a biologically compatible oral nanoformulation for a first-in-class drug beautifully designed for pediatric delivery that will be progressed toward further in vivo enabling studies. Finally, the nanosuspension could be considered a promising carrier for pediatric delivery of MA through the oral route with enhanced biological impact.

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Role of nanomaterial's as adsorbent for heterogeneous reaction in waste water treatment

Journal of Molecular Structure ◽

10.1016/j.molstruc.2021.130596 ◽

2021 ◽

pp. 130596

Author(s):

M. Sridevi ◽

C. Nirmala ◽

N. Jawahar ◽

G. Arthi ◽

Sugumari Vallinayagam ◽

...

Keyword(s):

Waste Water ◽

Water Treatment ◽

Heterogeneous Reaction ◽

Waste Water Treatment

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Arsenic Removal by Advanced Electrocoagulation Processes: The Role of Oxidants Generated and Kinetic Modeling

Catalysts ◽

10.3390/catal10080928 ◽

2020 ◽

Vol 10 (8) ◽

pp. 928

Author(s):

Micah Flor V. Montefalcon ◽

Meliton R. Chiong ◽

Augustus C. Resurreccion ◽

Sergi Garcia-Segura ◽

Joey D. Ocon

Keyword(s):

Kinetic Modeling ◽

Arsenic Removal ◽

Fold Increase ◽

Electrochemical Treatment ◽

Promising Alternative ◽

Iron Electrodes ◽

Removal Capacity ◽

Naturally Occurring ◽

Treatment Technologies

Arsenic (As) is a naturally occurring element in the environment that poses significant risks to human health. Several treatment technologies have been successfully used in the treatment of As-contaminated waters. However, limited literature has explored advanced electrocoagulation (EC) processes for As removal. The present study evaluates the As removal performance of electrocoagulation, electrochemical peroxidation (ECP), and photo-assisted electrochemical peroxidation (PECP) technologies at circumneutral pH using electroactive iron electrodes. The influence of As speciation and the role of oxidants in As removal were investigated. We have identified the ECP process to be a promising alternative for the conventional EC with around 4-fold increase in arsenic removal capacity at a competitive cost of 0.0060 $/m3. Results also indicated that the rate of As(III) oxidation at the outset of electrochemical treatment dictates the extent of As removal. Both ECP and PECP processes reached greater than 96% As(III) conversion at 1 C/L and achieved 86% and 96% As removal at 5 C/L, respectively. Finally, the mechanism of As(III) oxidation was evaluated, and results showed that Fe(IV) is the intermediate oxidant generated in advanced EC processes, and the contribution of •OH brought by UV irradiation is insignificant.

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Biosorption of Pb(II) Using Coffee Pulp as a Sustainable Alternative for Wastewater Treatment

Applied Sciences ◽

10.3390/app11136066 ◽

2021 ◽

Vol 11 (13) ◽

pp. 6066

Author(s):

Dora Luz Gómez-Aguilar ◽

Juan Pablo Rodríguez-Miranda ◽

Deisy Baracaldo-Guzmán ◽

Octavio José Salcedo-Parra ◽

Javier Andrés Esteban-Muñoz

Keyword(s):

Wastewater Treatment ◽

Agricultural Waste ◽

Green Technology ◽

Point Of Zero Charge ◽

Cellulose Content ◽

The Sustainable Development ◽

Coffee Pulp ◽

Biosorption Process ◽

Optimum Ph ◽

Development Goals

The present research shows the results obtained from the biosorption process of Pb, using coffee pulp as a biosorbent in synthetic waters. To do this, the lignin and cellulose content and the percentage of removal of Pb2+ ions was determined; additionally, the sorption’s optimal variables, such as the optimum pH, the point of zero charge (pHpzc), the kinetics and the adsorption isotherm, were determined. A comparison was made with other by-products derived from coffee crops. According to the results obtained in this research, the cellulose percentage was 29.12 ± 0.22% and the lignin percentage was 19.25 ± 0.16% in the coffee pulp, the optimum pH was 2.0 units and the kinetic model, which adjusted to the biosorption’s process, was the pseudo-second order of Ho and McKay, presenting an isotherm of Langmuir’s model and pHpzc of 3.95 units. Lastly, the removal of the pollutant was 86.45%, with a capacity of maximum adsorption of 24.10 mg·g−1 obtained with a particle size of 180 µm, time of contact of 105 min and at 100 RPM. Finally, we express that (a) the coffee pulp can be used as a sustainable alternative for the removal of the pollutant mentioned in synthetic and/or industrial wastewater matrices, to meet goals 3.9 and 6.9 of the Sustainable Development Goals of the 2030 agenda, and (b) the novelty of this research is the use of an agricultural waste of easy acquisition as a sorbent, without chemical modification, since it presented a high percentage of efficiency in the removal of Pb2+ ions. In turn, the challenge of this research is implementing this green technology on a pilot, semi-industrial and/or industrial scale in wastewater treatment systems.

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The Role of H2C2O4 and Na2CO3 as Precipitating Agents on The Physichochemical Properties and Photocatalytic Activity of Bismuth Oxide

Open Chemistry ◽

10.1515/chem-2020-0013 ◽

2020 ◽

Vol 18 (1) ◽

pp. 129-137

Author(s):

Yayuk Astuti ◽

Rizka Andianingrum ◽

Abdul Haris ◽

Adi Darmawan ◽

Keyword(s):

Photocatalytic Activity ◽

Methyl Orange ◽

Physicochemical Properties ◽

Bismuth Oxide ◽

Rate Constants ◽

Degradation Rate ◽

Precipitation Method ◽

Methyl Orange Degradation ◽

Methyl Orange Dye

AbstractSynthesis of bismuth oxide synthesis through the precipitation method using H2C2O4 and Na2CO3 precipitating agents, identification of physicochemical properties and its photocatalysis activity for methyl orange degradation were conducted. The bismuth oxide synthesis was undertaken by dissolving Bi(NO3)3.5H2O in HNO3, then added precipitating agents to form precipitate. The results showed that bismuth oxide produced by H2C2O4 precipitating agent was a yellow powder containing a mixture of α-Bi2O3 (monoclinic) and β-Bi2O3 (tetragonal), porous with size of 28-85 μm. Meanwhile, the use of Na2CO3 as precipitating agent resulted in bismuth oxide consisting of α-Bi2O3 and β-Bi2O3 and Bi2O4, irregular shape without pore being 40-115 μm in size. Bismuth oxide synthesized with H2C2O4 precipitating agent showed higher photocatalytic activity compared to bismuth oxide synthesized using Na2CO3 on degrading methyl orange dye with degradation rate constants of 2.35x10-5 s-1 for H2C2O4 and 1.81x10-5 s-1 for Na2CO3.

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Insights into Starch Coated Nanozero Valent Iron-Graphene Composite for Cr(VI) Removal from Aqueous Medium

Journal of Nanomaterials ◽

10.1155/2016/2813289 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 5

Author(s):

Prasanna Kumarathilaka ◽

Vimukthi Jayaweera ◽

Hasintha Wijesekara ◽

I. R. M. Kottegoda ◽

S. R. D. Rosa ◽

...

Keyword(s):

Point Of Zero Charge ◽

Inert Material ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

X Ray Diffraction ◽

Graphene Composite ◽

Removal Capacity ◽

Order Kinetic Model ◽

Pseudo Second Order ◽

First Time

Embedding nanoparticles into an inert material like graphene is a viable option since hybrid materials are more capable than those based on pure nanoparticulates for the removal of toxic pollutants. This study reports for the first time on Cr(VI) removal capacity of novel starch stabilized nanozero valent iron-graphene composite (NZVI-Gn) under different pHs, contact time, and initial concentrations. Starch coated NZVI-Gn composite was developed through borohydrate reduction method. The structure and surface of the composite were characterized by scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), and point of zero charge (pHpzc). The surface area and pHpzc of NZVI-Gn composite were reported as 525 m2 g−1 and 8.5, respectively. Highest Cr(VI) removal was achieved at pH 3, whereas 67.3% was removed within first few minutes and reached its equilibrium within 20 min obeying pseudo-second-order kinetic model, suggesting chemisorption as the rate limiting process. The partitioning of Cr(VI) at equilibrium is perfectly matched with Langmuir isotherm and maximum adsorption capacity of the NZVI-Gn composite is 143.28 mg g−1. Overall, these findings indicated that NZVI-Gn composite could be utilized as an efficient and magnetically separable adsorbent for removal of Cr(VI).

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