scholarly journals Modification of natural pumice by physical and chemical treatments for removal of zinc ions from aqueous solution

2019 ◽  
Vol 276 ◽  
pp. 06009
Author(s):  
Shinta Indah ◽  
Denny Helard ◽  
Budhi Primasari ◽  
Tivany Edwin ◽  
Riyan Hexa Putra
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Metal Uptake ◽  
Chemical Treatments ◽  
Batch System ◽  
Zn Uptake ◽  
Zn Concentration ◽  
West Sumatra ◽  
Modification Technique ◽  
Physical And Chemical

To increase the adsorption capability of natural pumice from Sungai Pasak, West Sumatra, Indonesia in removal of Zn from aqueous solution, modification by physical and chemical treatments were evaluated. The treatments were heating at temperatures of 300°C, 450°C, and 600°C for physical and soaking in acid solutions (HCl, H2SO4, and HNO3) for chemical treatments. The adsorption was performed in batch system with the optimum condition (6 of pH solution, < 63 um of adsorbent diameter, 3 g/L of adsorbent dose, 5 mg/L of Zn concentration, and 15 min of contact time). The results revealed that the removal efficiency and Zn uptake increase using modified pumice from 68.83% and 1.15 mg/g to 74.46% and 1.24 mg/g. The highest removal efficiency and Zn uptake were obtained from 300°C of heating temperatures and HCl for acid solution. The application of modified adsorbent for removal of Zn from aqueous solution showed that the modification technique has the potential to increase the removal efficiency and metal uptake of the natural pumice.

scholarly journals Removal of nitrate using modified pumice as adsorbent for reducing groundwater pollution

2021 ◽  
Vol 331 ◽  
pp. 02012
Author(s):  
Shinta Indah ◽  
Denny Helard ◽  
Gusti Lusiani ◽  
Diana Hapsari
Keyword(s):  
Removal Efficiency ◽  
Groundwater Pollution ◽  
Room Temperature ◽  
Nitrate Uptake ◽  
Sem Images ◽  
Chemical Treatments ◽  
Chemically Modified ◽  
Batch System ◽  
Nitrate Adsorption ◽  
Physical And Chemical

Nitrate adsorption onto the physically and chemically modified pumice was investigated as an effort for reducing groundwater pollution. The treatments were heating at temperatures of 300°C, 450°C, and 600°C for physical and soaking in acid solutions (HCl, H2SO4, and HNO3) for chemical treatments. The adsorption was performed in a batch system at room temperature (25±1°C) with the optimum condition (pH 4; 0.3 g/L of adsorbent dose; <63 µm of adsorbent diameters and 30 minutes of contact time). The results indicated that the physically and chemically modified pumice resulted in increasing removal efficiency and nitrate uptake compared to the natural pumice. The highest removal efficiency and nitrate uptake were achieved from 300°C of heating temperatures (62.04% and 155.09 mg/g) and H2SO4 for the acid solution (83.30% and 208.25 mg/g), while by using the natural pumice only reached 57.02 % and 142.55 mg/g. The SEM images of the modified pumice confirmed the change in the surface morphology of pumice including the pore structure and surface area which can be proper sites for adsorption of pollutants. This study demonstrated that physical and chemical modification could be the potential treatment to increase the removal efficiency and nitrate uptake of the natural pumice, thus can solve the problem of groundwater pollution.

scholarly journals Studies on desorption and regeneration of natural pumice for iron removal from aqueous solution

2018 ◽  
Vol 2017 (2) ◽  
pp. 509-515 ◽  
Author(s):  
S. Indah ◽  
D. Helard ◽  
A. Binuwara
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Contact Time ◽  
Adsorption Process ◽  
Iron Removal ◽  
Iron Ions ◽  
The Third ◽  
Environmental Friendly ◽  
West Sumatra ◽  
Adsorption Desorption

Abstract To make the adsorption process more economic and environmental friendly, it is necessary to study desorption and reutilization of the adsorbents. In the present study, the effectiveness of natural pumice in removal of iron from aqueous solution was investigated in several sorption-desorption cycles. The desorption characteristics of previously adsorbed iron ions on natural pumice were tested by various desorbing agents such as HCl, NaOH and aquadest. Among them, HCl showed the highest desorption efficiency (37.89%) with 0.1 M of concentration and 60 min of contact time. The removal efficiency of iron ions in reused natural pumice could be maintained up to 90% in the third cycle of adsorption. The results indicate that although complete desorption was not achieved, natural pumice from Sungai Pasak, West Sumatra, Indonesia, can be sufficiently reused up to three cycles of adsorption-desorption.

The chemical basis of gregariousness in cirripedes

1962 ◽  
Vol 156 (965) ◽  
pp. 500-520 ◽  
Keyword(s):  
Aqueous Solution ◽  
Related Species ◽  
Marine Organisms ◽  
Similar Response ◽  
Aqueous Extracts ◽  
Neutral Surface ◽  
Surface Rendering ◽  
Chemical Basis ◽  
Chemical Treatments ◽  
Physical And Chemical

Surfaces on which the cypris larvae of barnacles do not settle readily were treated with aqueous extracts of whole barnacles. Cyprids then settled on the treated surfaces as readily as they do on surfaces bearing adult barnacles, thus simulating the gregarious response to their own species. It is inferred that a settling factor, present in barnacle tissues, was transferred to a neutral surface rendering it favourable for settlement. The settling factor was shown to be non-dialyzable and stable to boiling in aqueous solution. When attached to a surface, it resisted severe physical and chemical treatments. The settling factor evoked a greater response from cyprids of the species used in preparing the extract than from cyprids of other species. Extracts made from other cirripedes and from all other arthropods tested, promoted settlement, but were less effective than extracts made from the same species of cirripede. The settling factor was found to be located mainly in the integument of arthropods and was present in greater amount in newly moulted individuals. It is suggested that the settling factor to which the cyprid responds may be the arthropodins of its own species, and that arthropodins of related species evoke a similar response. No evidence was found for chemotaxis, the cyprids responding to the settling factor only after alighting on the treated surface. It is thought likely that cyprids, in common with the larvae of many other sedentary marine organisms, may not be capable of detecting or responding to such chemical releasers in the sea unless they are in contact with the surface on which the chemical is adsorbed or from which it is diffusing.

Comparative Bio-sorption of Cadmium and Nickel Ions from Aqueous Solution onto Fibers of Date Palm using Fluidized Bed Column

2019 ◽  
Vol 70 (5) ◽  
pp. 1507-1512
Author(s):  
Baker M. Abod ◽  
Ramy Mohamed Jebir Al-Alawy ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Metal Ions ◽  
Fluidized Bed ◽  
Removal Efficiency ◽  
Heavy Metal Ions ◽  
Date Palm ◽  
Operating Conditions ◽  
Initial Concentration ◽  
Bed Height

The aim of this study is to use the dry fibers of date palm as low-cost biosorbent for the removal of Cd(II), and Ni(II) ions from aqueous solution by fluidized bed column. The effects of many operating conditions such as superficial velocity, static bed height, and initial concentration on the removal efficiency of metal ions were investigated. FTIR analyses clarified that hydroxyl, amine and carboxyl groups could be very effective for bio-sorption of these heavy metal ions. SEM images showed that dry fibers of date palm have a high porosity and that metal ions can be trapped and sorbed into pores. The results show that a bed height of 6 cm, velocity of 1.1Umf and initial concentration for each heavy metal ions of 50 mg/L are most feasible and give high removal efficiency. The fluidized bed reactor was modeled using ideal plug flow and this model was solved numerically by utilizing the MATLAB software for fitting the measured breakthrough results. The breakthrough curves for metal ions gave the order of bio-sorption capacity as follow: Cd(II)]Ni(II).

scholarly journals Efficient Sequestration of Hexavalent Chromium by Graphene-Based Nanoscale Zero-Valent Iron Composite Coupled with Ultrasonic Pretreatment

2021 ◽  
Vol 18 (11) ◽  
pp. 5921
Author(s):  
Haiyan Song ◽  
Wei Liu ◽  
Fansheng Meng ◽  
Qi Yang ◽  
Niandong Guo
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Inhibitory Effect ◽  
Ultrasonic Cavitation ◽  
Zero Valent Iron ◽  
Ultrasonic Pretreatment ◽  
Nanoscale Zero Valent Iron ◽  
Passivation Layers ◽  
Initial Ph ◽  
Two Phases

Nanoscale zero-valent iron (nZVI) has attracted considerable attention for its potential to sequestrate and immobilize heavy metals such as Cr(VI) from an aqueous solution. However, nZVI can be easily oxidized and agglomerate, which strongly affects the removal efficiency. In this study, graphene-based nZVI (nZVI/rGO) composites coupled with ultrasonic (US) pretreatment were studied to solve the above problems and conduct the experiments of Cr(VI) removal from an aqueous solution. SEM-EDS, BET, XRD, and XPS were performed to analyze the morphology and structures of the composites. The findings showed that the removal efficiency of Cr(VI) in 30 min was increased from 45.84% on nZVI to 78.01% on nZVI/rGO and the removal process performed coupled with ultrasonic pretreatment could greatly shorten the reaction time to 15 min. Influencing factors such as the initial pH, temperature, initial Cr(VI) concentration, and co-existing anions were studied. The results showed that the initial pH was a principal factor. The presence of HPO42−, NO3−, and Cl− had a strong inhibitory effect on this process, while the presence of SO42− promoted the reactivity of nZVI/rGO. Combined with the above results, the process of Cr(VI) removal in US-nZVI/rGO system consisted of two phases: (1) The initial stage is dominated by solution reaction. Cr(VI) was reduced in the solution by Fe2+ caused by ultrasonic cavitation. (2) In the following processes, adsorption, reduction, and coprecipitation coexisted. The addition of rGO enhanced electron transportability weakened the influence of passivation layers and improved the dispersion of nZVI particles. Ultrasonic cavitation caused pores and corrosion at the passivation layers and fresh Fe0 core was exposed, which improved the reactivity of the composites.

Investigation of layered double hydroxide/carbon dot nanocomposite on removal efficiency of Pb2+ from aqueous solution

2021 ◽  
pp. 116774
Author(s):  
Fataneh Vasheghani Farahani ◽  
Mohammad Hassan Amini ◽  
Seyed Hamid Ahmadi ◽  
Seyed Amirabbas Zakaria
Keyword(s):  
Aqueous Solution ◽  
Layered Double Hydroxide ◽  
Removal Efficiency ◽  
Carbon Dot ◽  
Double Hydroxide

Effects of physical and chemical treatments upon biophysical properties and micro-relief of human skin

2008 ◽  
Vol 300 (5) ◽  
pp. 243-251 ◽  
Author(s):  
Nicolas Atrux-Tallau ◽  
Ngoc T. T. Huynh ◽  
Laurie Gardette ◽  
Cyril Pailler-Mattéi ◽  
Hassan Zahouani ◽  
...  
Keyword(s):  
Human Skin ◽  
Biophysical Properties ◽  
Chemical Treatments ◽  
Physical And Chemical

scholarly journals Puparia Cleaning Techniques for Forensic and Archaeo-Funerary Studies

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 104
Author(s):  
Jennifer Pradelli ◽  
Fabiola Tuccia ◽  
Giorgia Giordani ◽  
Stefano Vanin
Keyword(s):  
Sodium Hydroxide ◽  
Molecular Identification ◽  
Sodium Hydroxide Solution ◽  
Species Level ◽  
Post Mortem ◽  
Molecular Analyses ◽  
Chemical Treatments ◽  
Wrong Identification ◽  
Physical And Chemical

Diptera puparia may represent both in forensic and archaeo-funerary contexts the majority of the entomological evidence useful to reconstruct the peri and post-mortem events. Puparia identification is quite difficult due to the lack of identification keys and descriptions. In addition, external substances accumulated during the puparia permanence in the environment make the visualization of the few diagnostic characters difficult, resulting in a wrong identification. Six different techniques based on physical and chemical treatments have been tested for the removal of external substances from puparia to make identification at species level feasible. Furthermore, the effects of these methods on successful molecular analyses have also been tested as molecular identification is becoming an important tool to complement morphological identifications. The results of this study indicate that cleaning via warm water/soap, the sonication and treatment with a sodium hydroxide solution are the best methods to achieve a good quality of the samples.

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