scholarly journals Extraction from aqueous solutions ions of iron and lead by filter loading, created on the basis of steel melting slag

Author(s):  
A. S. Panasyugin ◽  
S. V. Grigor’ev ◽  
A. I. Teran ◽  
V. N. Anufriev ◽  
A. R. Tsyganov ◽  
...  

The aim of the present paper is investigation of removal of Fe3+ and Pb2+ ions from aqueous media by material on the basis of steel melting slag. It has been established that the process of water purification from Fe3+ and Pb2+ ions by this material proceeds by a mixed mechanism both due to the formation of slightly soluble silicates and also due to the formation of hydroxides. When the filtration rate varies from 2 to 10 column volumes per hour, the percentage of sorption remains within 91,5–99,8%. The most optimal filtration rate is 6 column volumes per hour. Material on the basis of steel melting slag absorbs of Fe (III) up to 5 mg-eq/g and Pb (II) 0.64–1.27 mg-eq/g.

2016 ◽  
Vol 75 (1) ◽  
pp. 106-114 ◽  
Author(s):  
Lucas Meili ◽  
Társila Santos da Silva ◽  
Daniely Carlos Henrique ◽  
João Inácio Soletti ◽  
Sandra Helena Vieira de Carvalho ◽  
...  

In this work, the potential of ouricuri (Syagrus coronata) fiber as a novel biosorbent to remove methylene blue (MB) from aqueous solutions was investigated. The fiber was prepared and characterized according to the fundamental features for adsorption. A 23 experimental design was used to evaluate the effects of adsorbent dosage (M), fiber diameter (D) and agitation (A) on the adsorption capacity. In the more adequate conditions, kinetic and equilibrium studies were performed. The experimental design results showed that M = 10 g L−1), D = 0.595 mm and A = 200 rpm were the more adequate conditions for MB adsorption. Based on the kinetic study, it was found that the adsorption process was fast, being the equilibrium was attained at about 5 min, with 90% of color removal. The isotherm was properly represented by the Sips model, and the maximum adsorption capacity was 31.7 mg g−1. In brief, it was demonstrated that ouricuri fiber is an alternative biosorbent to remove MB from aqueous media, taking into account the process efficiency and economic viewpoint.


RSC Advances ◽  
2016 ◽  
Vol 6 (20) ◽  
pp. 16115-16121 ◽  
Author(s):  
Jason E. Camp ◽  
Jay J. Dunsford ◽  
Oliver S. G. Dacosta ◽  
Rebecca K. Blundell ◽  
James Adams ◽  
...  

Renewable sugar-derived palladium(0) nanoparticles (PdNPs) are effective as in situ formed catalysts for cross-coupling reactions in aqueous solutions.


Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1584 ◽  
Author(s):  
Ewa Szatyłowicz ◽  
Iwona Skoczko

Currently, methods of water purification and aqueous solutions leading to effective reduction of introduced chemical compounds into water purification systems have become the subject of research. Physical methods have become an alternative, because by subjecting water and aqueous solutions to UV (ultraviolet) radiation or magnetic fields (MF), either ultrasonic or electric, it is possible to influence the change of structure, which results in changes in the properties of water and aqueous solutions. This paper attempts to verify the influence of a weak magnetic field on the removal of iron and manganese compounds in the filtration process on gravel of 1–2 mm granulation, sand of 0.4–0.8 mm granulation, activated alumina and activated carbon. The conducted research proved that MF has a significant influence on the effectiveness of iron and manganese removal from water in the case of alumina, while in the filtration process through other filter materials the effect of MF was small.


1987 ◽  
Vol 70 (1) ◽  
pp. 22-23
Author(s):  
Paul Muneta ◽  
Richard Jasman ◽  
Luanne M Reid

Abstract The effects of freezing on nitrite stability in microbial cultures and in other liquid media were examined. Nitrite (12-13 mg (NO2)N/ 100 mL, pH 5.7) in culture and aqueous media was very unstable during frozen storage. Freezing resulted in the degradation of nitrite to other products including nitrate. Losses of 38-57% of the nitrite occurred after 15 days of frozen storage. Neither addition of chloroform nor a 5 min boiling treatment before freezing prevented nitrite destruction. However, nitrite concentration in the unfrozen portion of aqueous media increased during the freezing process. Nitrite can be stabilized during frozen storage by increasing the pH to near 11.0. For aqueous solutions, nitrite can be preserved by the use of chloroform or by increasing the pH to 11.0 and storing at 5°C.


2007 ◽  
Vol 95 (5) ◽  
Author(s):  
Nasir Khalid ◽  
Saqib Ali ◽  
Arif Iqbal ◽  
Shujaat Ahmad

The sorption of mercury ions from aqueous solutions on styrene-divinylbenzene copolymer beads (St-DVB) has been investigated for the decontamination of mercury from aqueous media. Various physico-chemical parameters, such as selection of appropriate electrolyte, contact time, amount of adsorbent, concentration of adsorbate, effect of diverse ions and temperature were optimized to simulate the best conditions which can be used to decontaminate mercury from aqueous media using St-DVB beads as an adsorbent. The radiotracer technique was used to determine the distribution of mercury. The highest adsorption was observed at 0.001 mol L


Author(s):  
Hamed Biglari ◽  
Susana RodríguezíCouto ◽  
Yusef Omidi Khaniabadi ◽  
Heshmatollah Nourmoradi ◽  
Mohammad Khoshgoftar ◽  
...  

AbstractIn this study, the potential of hexadecyl trimethyl ammonium bromide modified montmorillonite (HDTMA-Mt) to remove the synthetic dyes Alizarin Red S (ARS) and Bromocresol Green (BCG) from aqueous media was assessed. The effect of different factors including surfactant loading rate onto the clay, contact time, pH, adsorbent dosage and dye concentrations, on the removal of ARS and BCG in batch systems were investigated. The adsorbent was characterized by means of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffractometry (XRD). The equilibrium time for ARS and BCG was reached at 40 and 20 min, respectively, under optimized conditions (i.e. pH = 3, adsorbent dosage=1 g/L, surfactant loading rate onto the clay 70% of the cation exchange capacity (CEC) for ARS and 120% of the CEC for BCG, ARS concentration 50 mg/L and BCG concentration 500 mg/L). The adsorption rate of both dyes fitted the pseudo-second-order kinetic model and the equilibrium data was described by the Freundlich isotherm equation. The maximum monolayer adsorption capacities were equal to 666.6 and 1250 mg/g for ARS and BCG, respectively. Therefore, the HDTMA-Mt can be considered as an effective adsorbent for the removal of ARS and BCG from aqueous solutions.


Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2372 ◽  
Author(s):  
Nerea De Acha ◽  
César Elosúa ◽  
Francisco J. Arregui

A fluorescent optical fiber sensor for the detection of mercury (Hg2+) ions in aqueous solutions is presented in this work. The sensor was based on a fluorophore-labeled thymine (T)-rich oligodeoxyribonucleotide (ON) sequence that was directly immobilized onto the tip of a tapered optical fiber. In the presence of mercury ions, the formation of T–Hg2+-T mismatches quenches the fluorescence emission by the labeled fluorophore, which enables the measurement of Hg2+ ions in aqueous solutions. Thus, in contrast to commonly designed sensors, neither a fluorescence quencher nor a complementary ON sequence is required. The sensor presented a response time of 24.8 seconds toward 5 × 10−12 M Hg2+. It also showed both good reversibility (higher than the 95.8%) and selectivity: the I0/I variation was 10 times higher for Hg2+ ions than for Mn2+ ions. Other contaminants examined (Co2+, Ag+, Cd2+, Ni2+, Ca2+, Pb2+, Mn2+, Zn2+, Fe3+, and Cu2+) presented an even lower interference. The limit of detection of the sensor was 4.73 × 10−13 M Hg2+ in buffer solution and 9.03 × 10−13 M Hg2+ in ultrapure water, and was also able to detect 5 × 10−12 M Hg2+ in tap water.


2004 ◽  
Vol 6 (4) ◽  
pp. 227-231 ◽  
Author(s):  
E. Gkika ◽  
P. Kormali ◽  
S. Antonaraki ◽  
D. Dimoticali ◽  
E. Papaconstantinou ◽  
...  

Polyoxometallates (POM), i.e., metal oxide clusters of mainly tungsten are effective homogeneous photocatalysts for the mineralization of organic pollutants. POM are, at least, as effective as the well studiedTiO2.OH⋅radicals formed by the reaction of the photo-excited polyoxometallates withH2O, appear to play a key role in the process. In this study, the photocatalytic activity of POM have been tested on some diversified pesticides of interest such as lindane, bentazone and fenitrothion to determine the feasibility of decontamination of aqueous solutions from these pollutants. The results show that aqueous solutions containing the above pesticides, upon photolysis in the presence of polyoxotungstates undergo effective degradation toCO2,H2Oand the corresponding inorganic anions. The intermediates identified give rise to complicated degradation mechanisms prior to mineralization. The characteristic reactions that take place consist of hydroxylation, H-abstraction, dehalogenation, denitration, desulfurization, breaking of the C-C bond etc.


2010 ◽  
Vol 8 (3) ◽  
pp. 696-701 ◽  
Author(s):  
Ayman Massoud ◽  
F. Abou El-Nour ◽  
H. Killa ◽  
U. Seddik

AbstractThis work assesses the potential of an adsorptive material, Dowex 50w-x8, for the separation of indium ions from cadmium ions in aqueous media. The adsorption behavior of Dowex 50 w-x8 for indium and cadmium ions was investigated. The effect of pH, initial concentration of metal ions, the weight of resins, and contact time on the sorption of each of the metal ions were determined. It was found that the adsorption percentage of the indium ions was more than 99% at pH 4.0. The result shows that In (III) was most strongly extracted, while Cd(II) was slightly extracted at this pH value. The recovery of In(III) and Cd(II) ions is around 98% using hydrochloric acid as the best eluent.


2003 ◽  
Vol 57 (8) ◽  
pp. 1027-1038 ◽  
Author(s):  
Isabelle Billard ◽  
Eric Ansoborlo ◽  
Kathleen Apperson ◽  
Sylvie Arpigny ◽  
M. Emilia Azenha ◽  
...  

Results of an inter-laboratory round-robin study of the application of time-resolved emission spectroscopy (TRES) to the speciation of uranium(VI) in aqueous media are presented. The round-robin study involved 13 independent laboratories, using various instrumentation and data analysis methods. Samples were prepared based on appropriate speciation diagrams and, in general, were found to be chemically stable for at least six months. Four different types of aqueous uranyl solutions were studied: (1) acidic medium where UO22+aq is the single emitting species, (2) uranyl in the presence of fluoride ions, (3) uranyl in the presence of sulfate ions, and (4) uranyl in aqueous solutions at different pH, promoting the formation of hydrolyzed species. Results between the laboratories are compared in terms of the number of decay components, luminescence lifetimes, and spectral band positions. The successes and limitations of TRES in uranyl analysis and speciation in aqueous solutions are discussed.


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