Flotation Depression of Arsenopyrite Using Sodium Nitrobenzoate under Alkaline Conditions

Arsenopyrite is a common arsenic-containing mineral that is often closely associated with sulfide minerals, such as pyrite, chalcopyrite, pyrrhotite, galena, and sphalerite, and with precious metals, such as gold and silver. The selective inhibition of arsenopyrite is an important method used to reduce the arsenic content of processed products, the cost of arsenic removal in metallurgical processes, and its impact on the environment. In this study, we discovered a chemical sodium, m-nitrobenzoate (m-NBO), that can effectively inhibit the flotation behaviors of arsenopyrite via sodium butyl xanthate (NaBX), and these effects were studied by flotation experiments. The results showed that, using NaBX as a collector, arsenopyrite had good floatability under acidic conditions, but the floatability decreased under alkaline conditions. Furthermore, the organic inhibitor m-NBO had a significant inhibitory effect on arsenopyrite under alkaline conditions. In addition, the adsorption between m-NBO and NaBX was competitive, and a hydrophilic layer formed on the surface of arsenopyrite. The passivation film prevents dixanthogen from being adsorbed on the surface of the mineral. Due to the effect of m-NBO on arsenopyrite, the redox potential and oxide content of the arsenopyrite surface increased, the hydrophobicity of the arsenopyrite surface was reduced, and the flotation of arsenopyrite was inhibited. These results provide options for separating multimetal sulfide minerals and arsenic-containing minerals.

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Studying Kinetics of Arsenic Recovery from Copper Dross by Alkaline Sulfide Leaching

Materials Science Forum ◽

10.4028/www.scientific.net/msf.946.547 ◽

2019 ◽

Vol 946 ◽

pp. 547-551

Author(s):

A.A. Nabiyeva ◽

N.A. Kulenova ◽

S.V. Mamyachenkov

Keyword(s):

Arsenic Removal ◽

Precious Metals ◽

Production Cycle ◽

Arsenic Content ◽

Destructive Effect ◽

Lead Production ◽

Lead Bullion ◽

Removal Of Arsenic ◽

Kinetics Of ◽

Alkaline Sulfide

Copper dross are produced by rough decopperizing of blast furnace lead bullion. During liquation separation of copper dross from lead bullion most of arsenic and copper are concentrated in copper dross, arsenic content is approximately 4% As. Currently the processes for arsenic recovery from copper dross are understudied. In this work the focus is given to studying kinetics of the process for recovering arsenic from copper dross by alkaline-sulfide leaching. Alkaline sulfide leaching allows carrying out selective removal of arsenic into solution, keeping at this non-ferrous and precious metals in leaching residue. The studied method of alkaline sulfide leaching of copper dross provides backgrounds for developing technology that would allow processing of copper dross with selective arsenic removal from lead production cycle. By minimizing circulation of this harmful impurity in lead production it is possible to lessen destructive effect of its aggressive compounds on smelting-units refractory. Kinetics of alkaline sulfide leaching of copper dross was understudied up to date. This work is an attempt to fill the gap.

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Selective Inhibition of Thromboxane Synthetase with Dazoxiben - Basis of Its Inhibitory Effect on Platelet Adhesion

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657330 ◽

1983 ◽

Vol 49 (02) ◽

pp. 096-101 ◽

Cited By ~ 11

Author(s):

V C Menys ◽

J A Davies

Keyword(s):

Arachidonic Acid ◽

Platelet Adhesion ◽

Fold Increase ◽

Selective Inhibition ◽

Inhibitory Effect ◽

Selective Inhibitor ◽

Coated Glass ◽

Thromboxane Synthetase ◽

Pre Treatment

SummaryPlatelet adhesion to rabbit aortic subendothelium or collagen-coated glass was quantitated in a rotating probe device by uptake of radio-labelled platelets. Under conditions in which aspirin had no effect, dazoxiben, a selective inhibitor of thromboxane synthetase, reduced platelet adhesion to aortic subendothelium by about 40% but did not affect adhesion to collagen-coated glass. Pre-treatment of aortic segments with 15-HPETE, a selective inhibitor of PGI2-synthetase, abolished the inhibitory effect of dazoxiben on adhesion. Concentrations of 6-oxo-PGFlα in the perfusate were raised in the presence of dazoxiben alone, and following addition of thrombin (10 units/ml) there was a 2-3 fold increase in concentration. Perfusion of damaged aorta with platelets labelled with (14C)-arachidonic acid in the presence of thrombin and dazoxiben resulted in the appearance of (14C)-labelled-6-oxo-PGFiα. Inhibition of thromboxane synthetase limits platelet adhesion probably by promoting vascular synthesis of PGI2 from endoperoxides liberated from adherent platelets, which subsequently promotes detachment of cells from the surface.

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As(III) Removal by Dynamic Adsorption onto Amberlite XAD7 Functionalized with Crown Ether and Doped with Fe(III) Ions

Revista de Chimie ◽

10.37358/rc.19.7.7333 ◽

2019 ◽

Vol 70 (7) ◽

pp. 2330-2334

Author(s):

Mihaela Ciopec ◽

Adina Negrea ◽

Narcis Duteanu ◽

Corneliu Mircea Davidescu ◽

Iosif Hulka ◽

...

Keyword(s):

Adsorption Process ◽

Arsenic Removal ◽

Arsenic Concentration ◽

Fixed Bed ◽

World Health ◽

Arsenic Content ◽

Arsenic Adsorption ◽

Stage Of Development ◽

Wide Range ◽

Health Organization

Arsenic content in groundwater�s present a wide range of concentration, ranging from hundreds of micrograms to thousands of micrograms of arsenic per litter, while the maximum permitted arsenic concentration established by World Health Organization (WHO) is 10 mg L-1. According to the WHO all people, regardless of their stage of development and their social economic condition, have the right to have access to adequate drinking water. The most efficient and economic technique used for arsenic removal is represented by adsorption. In order to make this remediation technique more affordable and environmentally friendly is important to new materials with advance adsorbent properties. Novelty of present paper is represented by the usage of a new adsorbent material obtained by physical - chemical modification of Amberlite XAD polymers using crown ethers followed by iron doping, due to well-known affinity of arsenic for iron ions. Present paper aims to test the obtained modified Amberlite polymer for arsenic removal from real groundwater by using adsorption in a fixed bed column, establishing in this way a mechanism for the adsorption process. During experimental work was studied the influence of competing ions from real water into the arsenic adsorption process.

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Rostral ventral medulla 5-HT1A receptors selectively inhibit the somatosympathetic reflex

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.2001.280.5.r1261 ◽

2001 ◽

Vol 280 (5) ◽

pp. R1261-R1268 ◽

Cited By ~ 25

Author(s):

Takashi Miyawaki ◽

Ann K. Goodchild ◽

Paul M. Pilowsky

Keyword(s):

Blood Pressure ◽

Arterial Blood Pressure ◽

Sympathetic Nerve Activity ◽

Selective Inhibition ◽

Inhibitory Effect ◽

Ventrolateral Medulla ◽

Arterial Blood ◽

Potent Inhibition ◽

Somatosympathetic Reflex

The role of the 5-hydroxytryptamine (5-HT1A) receptors in the rostral ventrolateral medulla (RVLM) on somatosympathetic, baroreceptor, and chemoreceptor reflexes was examined in anesthetized rats. Microinjection of the selective 5-HT1A agonist 8-hydroxy-di- n-propylamino tetralin (8-OH-DPAT) decreased arterial blood pressure and splanchnic sympathetic nerve activity (SNA). Electrical stimulation of the hindlimb evoked early and late excitatory sympathetic responses. Bilateral microinjection in the RVLM of 8-OH-DPAT markedly attenuated both the early and late responses. This potent inhibition of the somatosympathetic reflex persisted even after SNA and arterial blood pressure returned to preinjection levels. Preinjection of the selective 5-HT1A antagonist NAN-190 in the RVLM blocked the sympathoinhibitory effect of 8-OH-DPAT and attenuated the inhibitory effect on the somatosympathetic reflex. 8-OH-DPAT injected in the RVLM did not affect baroreceptor or chemoreceptor reflexes. Our findings suggest that activation of 5-HT1A receptors in the RVLM exerts a potent, selective inhibition on the somatosympathetic reflex.

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Ion-Microprobe Quantification of Precious Metals in Sulfide Minerals

Applications of Microanalytical Techniques to Understanding Mineralizing Processes ◽

10.5382/rev.07.08 ◽

1997 ◽

pp. 155-167

Keyword(s):

Precious Metals ◽

Sulfide Minerals ◽

Ion Microprobe

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Liposomal delivery of methylphosphonate antisense oligodeoxynucleotides in chronic myelogenous leukemia [see comments]

Blood ◽

10.1182/blood.v84.2.601.601 ◽

1994 ◽

Vol 84 (2) ◽

pp. 601-607 ◽

Cited By ~ 35

Author(s):

AM Tari ◽

SD Tucker ◽

A Deisseroth ◽

G Lopez-Berestein

Keyword(s):

Growth Inhibition ◽

Cell Lines ◽

Chronic Myelogenous Leukemia ◽

Fusion Gene ◽

Hematologic Malignancy ◽

Control Cell ◽

Selective Inhibition ◽

Inhibitory Effect ◽

Myelogenous Leukemia ◽

Ph Chromosome

Abstract Chronic myelogenous leukemia (CML) is a hematologic malignancy characterized by the presence of the Philadelphia (Ph) chromosome. Bcr- abl, the fusion gene associated with the Ph chromosome, expresses a p210bcr-abl protein that promotes a selective expansion of mature myeloid progenitor cells. Methylphosphonate (MP) oligodeoxynucleotides complementary to specific regions of the bcr-abl mRNA were incorporated in liposomes. We studied the effects of liposomal MP (L-MP) on the growth inhibition of CML-like cell lines. L-MP targeted to the breakpoint junctions of the bcr-abl mRNA inhibited the growth of CML cells. Fifty percent inhibition was achieved at approximately 1 mumol/L of L-MP oligonucleotide concentrations. The inhibitory effect was selective because growth inhibition was observed only with CML but not with control cell lines. Moreover, CML cell growth inhibition was dependent on the sequence of the MP oligodeoxynucleotides incorporated in the liposomes. The growth inhibition of CML cells by L-MP resulted from selective inhibition of the expression of the p210bcr-abl protein.

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Selective Inhibition of Coxiella burnetii Replication by the Steroid Hormone Progesterone

Infection and Immunity ◽

10.1128/iai.00894-19 ◽

2020 ◽

Vol 88 (12) ◽

Author(s):

Zachary P. Howard ◽

Anders Omsland

Keyword(s):

Coxiella Burnetii ◽

Efflux Pump ◽

Q Fever ◽

Steroid Hormone ◽

Natural Infection ◽

Placental Tissue ◽

Selective Inhibition ◽

Inhibitory Effect ◽

Content Type ◽

Direct Inhibitory Effect

ABSTRACT Coxiella burnetii is a zoonotic bacterial obligate intracellular parasite and the cause of query (Q) fever. During natural infection of female animals, C. burnetii shows tropism for the placenta and is associated with late-term abortion, at which time the pathogen titer in placental tissue can exceed one billion bacteria per gram. During later stages of pregnancy, placental trophoblasts serve as the major source of progesterone, a steroid hormone known to affect the replication of some pathogens. During infection of placenta-derived JEG-3 cells, C. burnetii showed sensitivity to progesterone but not the immediate precursor pregnenolone or estrogen, another major mammalian steroid hormone. Using host cell-free culture, progesterone was determined to have a direct inhibitory effect on C. burnetii replication. Synergy between the inhibitory effect of progesterone and the efflux pump inhibitors verapamil and 1-(1-naphthylmethyl)-piperazine is consistent with a role for efflux pumps in preventing progesterone-mediated inhibition of C. burnetii activity. The sensitivity of C. burnetii to progesterone, but not structurally related molecules, is consistent with the ability of progesterone to influence pathogen replication in progesterone-producing tissues.

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Selective Inhibition of Platelet Agglutination and Aggregation by Aromatic Amidino Compounds

10.1055/s-0039-1680564 ◽

1977 ◽

Author(s):

J. D. Geratz ◽

R. R. Tidwell ◽

K. M. Brinkhous ◽

S. F. Mohammad

Keyword(s):

Selective Inhibition ◽

Inhibitory Effect ◽

Human Platelets ◽

The Other ◽

Future Studies ◽

Bovine Plasma ◽

Inhibitory Activities ◽

High Concentrations ◽

Ristocetin Cofactor ◽

Specific Inhibitors

A series of aromatic amidino compounds were investigated for their inhibitory effect on platelet agglutination and platelet aggregation. Agglutination of fresh or fixed human platelets was produced by bovine plasma or by human plasma in combination with ristocetin, while aggregation of fresh platelets was induced by ADP, thrombin or collagen. Highly effective inhibitors were found for both types of platelet clumping, but there was no parallelism between the inhibitory activities in the two test systems.5-(5-Amidino-2-benzimidazolyl)-2-(4-hydroxybenzene)benzimidazole suppressed agglutination exclusively. Pentamidine, on the other hand, strongly blocked the aggregation reactions, but did not interfere with agglutination, even at high concentrations. Compounds which inhibited aggregation also prevented the liberation of serotonin from the platelets.This investigation has led to the identification of new specific inhibitors of platelet agglutination and aggregation which can serve an important role in future studies of the two processes. The exact mode of interaction between ami dines and platelets is still being explored.. In the case of agglutination, inhibition most likely occurred at the level of binding of ristocetin cofactor to the platelet membrane. In the case of aggregation, however, interference could have taken place at the membranes or in the cytoplasm and could have been enzymatic or non-enzymatic in nature.

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Pilot-Scale Performance of Iron and Arsenic Removal from Contaminated Groundwater

Water Quality Research Journal ◽

10.2166/wqrj.2005.007 ◽

2005 ◽

Vol 40 (1) ◽

pp. 82-90 ◽

Cited By ~ 8

Author(s):

Biswaranjan Manna ◽

Uday Chand Ghosh

Keyword(s):

Arsenic Removal ◽

Cost Effective ◽

Pilot Scale ◽

Cost Evaluation ◽

Contaminated Groundwater ◽

Arsenic Content ◽

Hand Pump ◽

Excess Iron ◽

Tube Wells ◽

Performance Results

Abstract Pilot-scale performance in reducing excess iron and arsenic from contaminated groundwater has been systematically reported. Here, a double column unit, the first packed with β-MnO2 and the second with crystalline FeOOH (goethite variety), with filters attached to the outlet of hand-pump tube-wells has been used in the field. Results showed that the filters generate 10,000 to 15,000 BV and 19,000 to 35,000 BV water with iron ≤ 0.3 mg/L and arsenic ≤10 µg/L from groundwater having influent iron and arsenic levels of 3.75 to 7.25 mg/L and 70 to 220 µg/L, respectively. The downflow rate of effluent water was 237.6 to 305.5 L/m2-min. The performance results were achieved with a single charging of the iron and arsenic removal media. Toxicity characteristic leaching procedure (TCLP) tests of the waste (arsenic content: 2.4 g/kg) showed that it is not hazardous to the environment and does not pose any risk to users. Cost evaluation showed $US0.50 to 0.70 per 1000 gallons of treated water and, hence, the technology is cost-effective for countries such as India and Bangladesh.

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