Pathways Contributing to the Formation and Decay of Ferrous Iron in Sunlit Natural Waters

2011 ◽  
pp. 153-176 ◽  
Author(s):  
Shikha Garg ◽  
Andrew L. Rose ◽  
T. David Waite
Keyword(s):  
Ferrous Iron ◽  
Natural Waters

An experimental study on iron removal with ferric sludge recycling

2000 ◽  
Vol 42 (1-2) ◽  
pp. 393-397 ◽  
Author(s):  
N. Tufekci ◽  
H.Z. Sarikaya ◽  
I. Ozturk
Keyword(s):  
Reaction Kinetics ◽  
Ferrous Iron ◽  
Natural Waters ◽  
Ferric Iron ◽  
Ferric Hydroxide ◽  
Iron Removal ◽  
Aeration Tank ◽  
Batch Reactors ◽  
High Concentration ◽  
Activated Sludge Processes

An iron removal process, which makes use of the catalytic effect of ferric iron, is proposed. For this purpose, the reaction kinetics derived from the data of the batch experiments was applied to the continuous flow system. Based upon this reaction kinetics, it has been theoretically demonstrated that the volumes of aeration tanks can be significantly reduced by keeping a high concentration of ferric iron in the reactor. However, in natural waters, Fe(II) is found commonly to be in the range of 0.01–10 mg/l. These ferrous iron concentrations are not high enough to maintain the high concentrations of ferric iron in the aeration tank. Therefore, similar to the activated sludge processes used in wastewater treatment, it is suggested that the required Fe(III) concentrations can be maintained by recycling Fe(OH)3 sludge back to the aeration tank. It is known that the oxygenation of ferrous iron is catalyzed by the reaction product, ferric hydroxide. Catalytic action of the ferric iron sludges on the oxidation of ferrous iron by aeration has been identified and the kinetics of this catalytic reaction has been formulated by the authors. The oxidation of Fe(II) was studied in batch reactors in which the concentration of Fe(III) was in the range of 0–600 mg/l. The oxygenation rate increased linearly with the increasing Fe(III) concentrations up to 50 mg/l and a second-order polynomial relationship was found between the reaction rate and the Fe(III) concentrations in the range of 50–600 mg/l. The required volume (V) of the aeration tank and the effluent Fe(II) concentrations were determined as a function of the Fe(III) concentration. The volume of the aeration tank required for the same Fe(II) conversion was reduced by a factor of 15 when the Fe(III) concentration was raised from 0 to 600 mg/l at pH=6.7. No incremental benefit of the increase of Fe(III) concentration was observed at Fe(III) levels beyond the 600 mg/l. This study has experimentally demonstrated that significant savings can be achieved in iron removal systems by recirculating the Fe(III) sludges back to the aeration tank.

scholarly journals The determination of ferrous iron in natural waters with 2,2′ bipyridyl

1977 ◽  
Vol 22 (4) ◽  
pp. 753-760 ◽  
Author(s):  
S. I. Heaney ◽  
W. Davison
Keyword(s):  
Ferrous Iron ◽  
Natural Waters

PENDEKATAN EKSPLORASI RESERVOIR ONSHORE MELALUI PEMETAAN REMBESAN MIKRO HIDROKARBON DENGAN CITRA HIPERSPEKTRAL

2019 ◽  
Vol 3 ◽  
pp. 1181
Author(s):  
Muhamad Iqbal Januadi Putra
Keyword(s):  
Ferrous Iron

Kapabilitas citra satelit hiperspektral yang memiliki keunggulan spektral sangat berpotensi untuk dimanfaatkan dalam eksplorasi keberadaan reservoir onshore. Kemampuan ini dilakukan melalui perekaman spektral fenomena rembesan mikro hidrokarbon yang menimbulkan ekspresi anomali spektral tanah dan menjadi kunci keberadaan sumber hidrokarbon. Dalam penelitian ini, Sub-Cekungan Jatibarang dipilih sebagai wilayah penelitian. Berdasarkan teori spektral rembesan mikro hidrokarbon, citra Hyperion dapat digunakan sebagai alat untuk mendeteksi keberadaan fenomena rembesan mikro hidrokarbon sebagai penduga keberadaan reservoir onshore karena memiliki spektrum panjang gelombang yang peka terhadap objek anomali hidrokarbon. Sehingga, penelitian ini bertujuan untuk mendeteksi area rembesan mikro hidrokarbon dengan citra Hyperion di Cekungan Jatibarang. Hydrocarbon Index (HI) yang memanfaatkan saluran 155 (1.699 nm), 158 (1.729 nm), dan 160 (1.749 nm) digunakan sebagai algoritma untuk medeteksi area rembesan mikro hidrokarbon di Sub-Cekungan Jatibarang. Gejala anomali alterasi kaolinite, ferrous iron dan gejala anomali vegetasi dengan indeks NDVI digunakan sebagai pembanding akurasi HI. Hasil penelitian ini menunjukkan adanya sebaran rembesan mikro hidrokarbon di wilayah Kecamatan Tukdana (Indramayu), Kecamatan Pasekan (Indramayu), dan Kecamatan Ligung (Majalengka). Area sebaran rembesan mikro hidrokarbon teraglomerasi pada wilayah pesisir utara Kecamatan Pasekan. Secara umum, keberadaan rembesan mikro hidrokarbon berkorelasi dengan tingkat anomali alterasi kaolinite, ferrous iron, dan anomali vegetasi.

Synthesis and Breakdown of the Universal Precursors to Biological Metabolism Promoted by Ferrous Iron

2018 ◽  
Author(s):  
Kamila B. Muchowska ◽  
Sreejith Jayasree VARMA ◽  
Joseph Moran
Keyword(s):  
Amino Acids ◽  
Chemical Reaction ◽  
Metabolic Pathways ◽  
Ferrous Iron ◽  
Reaction Network ◽  
Tca Cycle ◽  
Chemical Reaction Network ◽  
Metabolic Precursors ◽  
Tca Cycle Intermediates

How core biological metabolism initiated and why it uses the intermediates, reactions and pathways that it does remains unclear. Life builds its molecules from CO<sub>2 </sub>and breaks them down to CO<sub>2 </sub>again through the intermediacy of just five metabolites that act as the hubs of biochemistry. Here, we describe a purely chemical reaction network promoted by Fe<sup>2+ </sup>in which aqueous pyruvate and glyoxylate, two products of abiotic CO<sub>2 </sub>reduction, build up nine of the eleven TCA cycle intermediates, including all five universal metabolic precursors. The intermediates simultaneously break down to CO<sub>2 </sub>in a life-like regime resembling biological anabolism and catabolism. Introduction of hydroxylamine and Fe<sup>0 </sup>produces four biological amino acids. The network significantly overlaps the TCA/rTCA and glyoxylate cycles and may represent a prebiotic precursor to these core metabolic pathways.

THE MECHANISM OF NITRATES TRANSFORMATION IN THE PROCESSES OF ELECTROCHEMICAL TREATMENT OF NATURAL WATERS

2002 ◽  
Vol 1 (3) ◽  
pp. 341-346
Author(s):  
Viorica Iambartev ◽  
Gheorghe Duca ◽  
Maria Gonta ◽  
Vera Matveevici
Keyword(s):  
Natural Waters ◽  
Electrochemical Treatment
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