Impact of Buffering Agent on Lead Adsorption of Bentonite: An Appraisal

Abstract Industrialization increases the number of heavy metals released into the environment. Lead (Pb2+), nickel (Ni2+) and chromium (Cr6+) are among these toxic metals and cause irreversible effects on ecosystems and human health due to their bio-accumulative potential. The decontamination through adsorption processes using lignocellulosic wastes from agricultural and/or forestry processes is a viable solution. Hence, this work aimed at studying the effect of pH on the biosorption of the metal ions using four different by-product materials: walnut shell, chestnut shell, pinewood and burnt pinewood. These experiments were conducted with solutions of the three heavy metals in which the adsorbents were immersed to measure the rate of adsorption. A range of pH values from 3.0 to 7.5 was used in the experiments, and the concentrations were determined by atomic absorption. The results showed different behaviour of the biosorbent materials when applied to the different metals. The lead adsorption had an ideal pH in the range of 5.5–7.5 when the walnut shell was used as an adsorbent, corresponding to values of adsorption greater than 90%, but for the other materials, maximum adsorption occurred for a pH of 7.5. For the adsorption of chromium, the pH was very heterogeneous with all adsorbents, with optimal values of pH varying from 3.0 (for chestnut shell) to 6.5 (for walnut shell and wood). For nickel, the best pH range was around pH 5, with different values according to the lignocellulosic material used. These results indicate that the tested biosorbents have the potential to decontaminate wastewater in variable extensions and that by controlling the pH of the solution; a more efficient removal of the heavy metals can be achieved.

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Lead adsorption on loess under high ammonium environment

Environmental Science and Pollution Research ◽

10.1007/s11356-020-10777-1 ◽

2020 ◽

Author(s):

Shaoyi Wang ◽

Jiawei Wu ◽

Jianqun Jiang ◽

Shakil Masum ◽

Haijian Xie

Keyword(s):

Lead Adsorption

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Preparation of Biochar and Its Metal Complexes and Study on Their Lead Adsorption Properties

Integrated Ferroelectrics ◽

10.1080/10584587.2020.1728829 ◽

2021 ◽

Vol 213 (1) ◽

pp. 53-66

Author(s):

Qing Zhang ◽

Meina Liang ◽

Xiaozhang Yuan ◽

Shuiping Xu ◽

Lili Huang

Keyword(s):

Metal Complexes ◽

Adsorption Properties ◽

Lead Adsorption

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Pharmaceutical applications of citric acid

Future Journal of Pharmaceutical Sciences ◽

10.1186/s43094-021-00203-9 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Sopan Nangare ◽

Yogini Vispute ◽

Rahul Tade ◽

Shailesh Dugam ◽

Pravin Patil

Keyword(s):

Citric Acid ◽

Biomedical Applications ◽

Antioxidant Systems ◽

Coating Agent ◽

Branched Polymer ◽

Pharmaceutical Applications ◽

Buffering Agent ◽

Animal Metabolism ◽

Polymer Capping ◽

Flavoring Agent

Abstract Background Citric acid (CA) is a universal plant and animal-metabolism intermediate. It is a commodity chemical processed and widely used around the world as an excellent pharmaceutical excipient. Notably, CA is offering assorted significant properties viz. biodegradability, biocompatibility, hydrophilicity, safety, etc. Therefore, CA is broadly employed in many sectors including foodstuffs, beverages, pharmaceuticals, nutraceuticals, and cosmetics as a flavoring agent, sequestering agent, buffering agent, etc. From the beginning, CA is a regular ingredient for cosmetic pH-adjustment and as a metallic ion chelator in antioxidant systems. In addition, it is used to improve the taste of pharmaceuticals such as syrups, solutions, elixirs, etc. Furthermore, free CA is also employed as an acidulant in mild astringent preparations. Main text In essence, it is estimated that the functionality present in CA provides excellent assets in pharmaceutical applications such as cross-linking, release-modifying capacity, interaction with molecules, capping and coating agent, branched polymer nanoconjugates, gas generating agent, etc. Mainly, the center of attention of the review is to deliver an impression of the CA-based pharmaceutical applications. Conclusion In conclusion, CA is reconnoitered for multiple novels pharmaceutical and biomedical/applications including as a green crosslinker, release modifier, monomer/branched polymer, capping and coating agent, novel disintegrant, absorption enhancer, etc. In the future, CA can be utilized as an excellent substitute for pharmaceutical and biomedical applications. Graphical abstract

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Nanostructured Didymosphenia geminata-based membrane for efficient lead adsorption from aqueous solution

Journal of Environmental Chemical Engineering ◽

10.1016/j.jece.2021.105269 ◽

2021 ◽

Vol 9 (4) ◽

pp. 105269

Author(s):

Elias Reinoso-Guerra ◽

Juliet Aristizabal ◽

Bárbara Arce ◽

Elsie Zurob ◽

Geraldine Dennett ◽

...

Keyword(s):

Aqueous Solution ◽

Lead Adsorption ◽

Didymosphenia Geminata

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Measurements of Metal Adsorption in Oxide-Clay Mixtures: “Competitive-Additivity” Among Mixture Components

MRS Proceedings ◽

10.1557/proc-294-791 ◽

1992 ◽

Vol 294 ◽

Cited By ~ 3

Author(s):

V. S. Tripathi ◽

M.D. Siegel ◽

Z. S. Kooner

Keyword(s):

Surface Complexation ◽

Particle Interactions ◽

Complexation Constants ◽

Lead Adsorption ◽

Adsorption Sites ◽

Adsorption Behaviors ◽

Limited Success ◽

Ph Dependent ◽

Waste Repositories ◽

Zinc Adsorption

ABSTRACTAn important question concerning the transport of radionuclides from nuclear waste repositories is whether the adsorption of metals by rocks and soils can be predicted from the properties of the constituent minerals. Attempts by previous researchers to use sorption models based on linear adsorption or weighted "sorptive additivity" have met with limited success. In this study, a “competitive-additivity” model based on surface complexation theory was used to model the pH-dependent adsorption of lead by goethite/Ca-montmorillonite mixtures using complexation constants obtained from single sorbent systems. Measurements of lead adsorption by goethite, Ca-montmorillonite, and goethite-Ca-montmorillonite mixtures (and similar studies of copper and zinc adsorption) demonstrate that the two adsorbents compete for adsorption of metals over wide ranges of pH and concentrations of adsorbents and metals. The adsorption behaviors of the mixtures are determined by the relative concentrations of the adsorbents and their respective affinities for the adsorbate metal. Particle-particle interactions such as heterocoagulation of the oxide and clay do not appear to be significant for the majority of the adsorption sites in this system.

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A comparative study of lead adsorption by activated Khaya Ivoresnsis and Pycanthus Angolensis sawdust

Journal of Water Sanitation and Hygiene for Development ◽

10.2166/washdev.2016.070 ◽

2016 ◽

Vol 6 (4) ◽

pp. 593-601

Author(s):

Chidozie Charles Nnaji ◽

Stephen Chinwike Emefu

Keyword(s):

Experimental Data ◽

Freundlich Isotherm ◽

Intraparticle Diffusion ◽

Bulk Liquid ◽

Timber Species ◽

Particle Sizes ◽

Lead Adsorption ◽

Intraparticle Diffusion Model ◽

First Order Kinetics ◽

Good Agreement

Experiments investigating lead adsorption by activated sawdust of different particle sizes of two timber species were conducted. The experimental data were fitted to isothermal and kinetic models. The optimum particle size was 0.85 mm for Khaya ivorensis and 1.18 mm for Pycanthus angolensis. The adsorption of lead by Khaya ivorensis and Pycanthus angolensis conformed to the Langmuir isotherm (0.83 ≤ R2 ≤ 0.96 and 0.86 ≤ R2 ≤ 0.98, respectively) and Freundlich isotherm (0.69 ≤ R2 ≤ 0.97 and 0.94 ≤ R2 ≤ 1.0, respectively). The adsorption process for the two species of timber was controlled by solute transport in the bulk liquid and intraparticle diffusion which was confirmed by good agreement of experimental data with pseudo-first-order kinetics (0.96 ≤ R2 ≤ 1.0 for Khaya ivorensis and 0.9 ≤ R2 ≤ 1.0 for Pycanthus angolensis) and the intraparticle diffusion model (0.9 ≤ R2 ≤ 0.99 for Khaya ivorensis and 0.84 ≤ R2 ≤ 0.97 for Pycanthus angolensis). A new kinetic model was developed with R2 of 0.93 ≤ R2 ≤ 0.99 for Khaya ivorensis and 0.88 ≤ R2 ≤ 1.0 for Pycanthus angolensis.

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Buffering Agent-Induced Lactose Content Increases via Growth Hormone-Mediated Activation of Gluconeogenesis in Lactating Goats

Physiological Research ◽

10.33549/physiolres.933715 ◽

2018 ◽

pp. 317-329 ◽

Cited By ~ 3

Author(s):

L. LI ◽

M. L. HE ◽

Y. LIU ◽

Y. S. ZHANG

Keyword(s):

Growth Hormone ◽

Milk Yield ◽

Phosphoenolpyruvate Carboxykinase ◽

Volatile Fatty Acids ◽

Glucose Transporter ◽

Glucose Content ◽

Blood Concentrations ◽

Lactating Goats ◽

Buffering Agent ◽

Lactose Synthesis

Dairy goats are often fed a high-concentrate (HC) diet to meet their lactation demands; however, long-term concentrate feeding is unhealthy and leads to milk yield and lactose content decreases. Therefore, we tested whether a buffering agent is able to increase the output of glucose in the liver and influence lactose synthesis. Eight lactating goats were randomly assigned to two groups: one group received a HC diet (Concentrate : Forage = 6:4, HG) and the other group received the same diet with a buffering agent added (0.2 % NaHCO3, 0.1 % MgO, BG) over a 19-week experimental period. The total volatile fatty acids and lipopolysaccharide (LPS) declined in the rumen, which led the rumen pH to become stabile in the BG goats. The milk yield and lactose content increased. The alanine aminotransferase, aspartate transaminase, alkaline phosphatase, pro-inflammatory cytokines, LPS and lactate contents in the plasma significantly decreased, whereas the prolactin and growth hormone levels increased. The hepatic vein glucose content increased. In addition, pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6PC) expression in the liver was significantly up-regulated. In the mammary glands, the levels of glucose transporter type 1, 8, 12 as well as of sodium-glucose cotransporter 1 increased. Cumulative buffering agent treatment increased the blood concentrations of glucose via gluconeogenesis and promoted its synthesis in the liver. This treatment may contribute to the increase of the milk yield and lactose synthesis of lactating goats.

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Lead Adsorption in Lubricant Waste using Zeolite

Jurnal Rekayasa Proses ◽

10.22146/jrekpros.49489 ◽

2020 ◽

Vol 14 (1) ◽

Author(s):

'Aini Rahmadhaniar ◽

Ratri Ariatmi Nugrahani ◽

Nurul Fithriyah ◽

Titik Lestariningsih

Keyword(s):

Contact Time ◽

Adsorption Process ◽

Lead Content ◽

Government Regulations ◽

Lead Adsorption ◽

Zeolite Adsorbent

Lubricant waste is one of the hazardous refuses which are regulated on the limit of lead content according to Government Regulations (Kep-51/MenLH/10/1995). Therefore, it is necessary to research for reducing the lead content. The purpose of this study is to understand the effect of adding adsorbents to decrease lead content in waste of lubricants taken from ships. The waste lubricant was recycled by adsorption using zeolite. Lubricant waste samples of 200 mL each were physically and chemically identified subjected to adsorption process using zeolite adsorbent whose concentrations (%w/w) were varied as follows: 7.5%, 13.25%, 14.25%, 15.75% and 17.5% with stirring speed of 150 rpm and contact time for 60 minutes. The best results were obtained at the adsorbent amount of 26.5 grams (concentration of 13.25%), for which lead content reduction reached 83%. The ANOVA F was obtained to be 13.42, and hence the study concluded that the amount of the adsorbent was related to the decrease in lead content.A B S T R A KPelumas bekas adalah salah satu limbah berbahaya yang dibatasi kadar timbalnya dalam Peraturan Pemerintah, sehingga perlu penelitian untuk menurunkan kadar timbal. Tujuan penelitian ini adalah untuk memahami pengaruh penambahan adsorben untuk menurunkan kadar timbal dalam pelumas bekas yang berasal dari mesin kapal. Pelumas bekas didaur ulang dengan adsorpsi menggunakan zeolit. Setiap sampel berisi 200 mL pelumas bekas yang telah diidentifikasi sifat fisika dan kimia-nya diadsorpsi menggunakan adsorben zeolit. Variasi konsentrasi zeolit (%w/w) yang digunakan yaitu: 7,5%; 13,25%; 14,25%; 15,75% dan 17,5% dengan kecepatan pengadukan 150 rpm dan waktu kontak 60 menit. Hasil terbaik diperoleh pada jumlah adsorben 26,5 g (konsentrasi 13,25%) dengan penurunan kadar timbal mencapai 83%. Faktor F pada hasil ANOVA adalah 13,42. Dengan demikian dapat disimpulkan bahwa terdapat korelasi antara konsentrasi adsorben dan penurunan kadar timbal.

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