Metal storage capacity evaluation of humic and himatomelanic acids hydroxymethyl derivatives obtained from brown coal

2021 ◽  
Author(s):  
I.A. Potapova ◽  
E.V. Nielina ◽  
N.V. Prokhorova
Keyword(s):  
Heavy Metals ◽  
Chemical Modification ◽  
Humic Substances ◽  
Brown Coal ◽  
Copper Ions ◽  
Phenol Formaldehyde ◽  
Humus Substances ◽  
Capacity Evaluation ◽  
Methyl Derivatives ◽  
Himatomelanic Acids

Humic substances represent the most extensive and reactive class of natural compounds. A more nature-saving way is to obtain humus substances from solid combustible minerals and waste from their processing. The ability of these compounds to form stable complexes with heavy metals, which increases with their directed chemical modification, has been experimentally confirmed. The effectiveness of the phenol-formaldehyde condensation method for the modification of initial humus substances has been confirmed. The interaction of humic and himatomelanic acids with formaldehyde leads to an increase in sorption activity in comparison with the initial humic acids with respect to heavy metals. This aspect has been studied and confirmed in model experiments with copper ions. Key words: humic substances, brown coal, humic and himatomelanic acids, directed chemical modification, hydroxymethyl (methyl) derivatives, heavy metals, copper ions, complex formation.

SORPTION MATERIALS BASED ON ALKALI-INSOLUBLE COMPONENTS PEAT AND BROWN COAL FOR WASTEWATER TREATMENT FROM IONS OF HEAVY METAL

2021 ◽  
pp. 175-186
Author(s):  
Natalia S. Pershay ◽  
Yuriy G. Yanuta
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Wastewater Treatment ◽  
Metal Ions ◽  
Organic Compounds ◽  
Brown Coal ◽  
Heavy Metal Ions ◽  
Copper Ions ◽  
Exchange Capacity ◽  
Water Soluble

The problem of environmental pollution with heavy metals is relevant for the Republic of Belarus. One of the ways to remove heavy metals from industrial wastewater is to treat them with sorbents. Sorbents based on peat and brown coal are effective and inexpensive, but their use leads to secondary contamination of the treated environment with water-soluble organic compounds. It is shown that the developed sorption materials based on peat and brown coal residues sorb heavy metal ions (copper, nickel, zinc) and do not pollute the treated medium with water-soluble organic compounds (the COС value of sorption materials does not exceed 5 mg O2/dm3). It was found that the exchange capacity of sorption materials in an acidic medium (pH 2.0) is higher than that of humic acids and is in the range of 0.17–1.38 mmol/g. The use of ultrasonic treatment to increase the exchange capacity of sorption materials makes it possible to increase it by 2.3–3.0 times for copper ions and 2.2 times for zinc ions, which is due to the destruction of large aggregates. The obtained results formed the basis for the development of a technology for obtaining sorption materials for wastewater treatment from heavy metal ions.

Study of Detoxifying Ability of Oxidized Humic Substances under the Conditions of Oil Pollution of Soils

2021 ◽  
Vol 625 (3) ◽  
pp. 53-56
Author(s):  
N. A. Likhacheva ◽  
◽  
E. A. Zaharova ◽  
Keyword(s):  
Chemical Modification ◽  
Humic Substances ◽  
Brown Coal ◽  
Contaminated Soil ◽  
Petroleum Hydrocarbons ◽  
Oil Pollution ◽  
Oxidative Modification ◽  
Noticeable Increase ◽  
Bioassay Method

The article presents the results of research on the oxidative modification of humic substances of brown coal of the Tyulgan deposit. The detoxifying effect of the obtained substances in relation to petroleum hydrocarbons was studied using the bioassay method. During the evaluation, a noticeable increase in the detoxifying ability was found in the result of chemical modification of humic substances. The greatest detoxifying effect in relation to oil pollution of the soil was observed for humic substances modified by oxidation and amounted to 19 and 42% at doses of 0.01 and 0.1% by weight. accordingly. The detoxifying effect of native humic substances is significantly lower: 9 and 2 % at doses of 0.01% and 0.1% by weight. accordingly. Thus, the prospects of using oxidized humic substances as sorbents-detoxicants during phytoremediation of oil-contaminated soil are shown.

scholarly journals Applicability of the modified diatomite for treatment of wastewater containing heavy metals

2021 ◽  
Vol 247 ◽  
pp. 01052
Author(s):  
Dmitry Boriskov ◽  
Sanya Efremova ◽  
Nadezhda Komarova ◽  
Elena Tikhomirova ◽  
Aleksey Bodrov
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Chemical Modification ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Copper Ions ◽  
Raw Material ◽  
Wastewater Purification ◽  
Physical And Chemical ◽  
Modified Sorbents

The paper studies various modifications of diatomite, aiming at creating sorbents for wastewater purification from heavy metal ions. Diatomite of the Akhmatovskoe deposit of the Penza region was considered as a raw material. The processes of physical and chemical modification of diatomite were investigated. Adsorption isotherms were constructed, quantitative characteristics of adsorption of copper ions on the surface of modified sorbents were obtained. A chemical modification (acidic and alkaline) is proposed, which results in an increased adsorption capacity for heavy metal ions. The applicability of diatomite for the purification of highly concentrated wastewater containing heavy metals is shown.

"PARAMETERS’ INFLUENCE OF CRUSHING BROWN COAL TO THE EXTRACTION OF HUMIC SUBSTANCES "

2017 ◽  
Vol 17 (6) ◽  
pp. 204-209
Author(s):  
K.S. Votolin ◽  
◽  
S.I. Zherebtsov ◽  
M.Y. Klimovich ◽  
O.V. Smotrina ◽  
...  
Keyword(s):  
Humic Substances ◽  
Brown Coal

scholarly journals Bacillus aryabhattai TFG5-mediated synthesis of humic substances from coir pith wastes

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Iniyakumar Muniraj ◽  
Syed Shameer ◽  
Priyadharshini Ramachandran ◽  
Sivakumar Uthandi
Keyword(s):  
Humic Substances ◽  
Copper Ions ◽  
Degradation Products ◽  
Terrestrial Ecosystem ◽  
Wash Water ◽  
Bacillus Aryabhattai ◽  
Coir Pith ◽  
Effective Synthesis ◽  
Ft Ir ◽  
Degree Of Condensation

Abstract Background Humic substances (HS) form the largest proportion among all the constituents of soil organic matter and are a key component of the terrestrial ecosystem. HS plays a multifunctional role in the environment by controlling the biogeochemical carbon cycle, providing nutrients and bio-stimulants for plant growth, and interacting with inorganic and organic pollutants. The rate of formation of HS in soils determines its productivity and carbon sequestration capacity. Enhancement of HS synthesis in the soil through the microbial route not only increases CO2 sequestration but also mitigates the greenhouse gas emissions in the environment. Result In this study, we attempted to understand the mechanism of formation and enhancement of HS from coir pith wastes using the tyrosinase produced by Bacillus aryabhattai TFG5. The bacterium TFG5 isolated from the termite garden produced the tyrosinase (1.34 U mL−1) and laccase (2.1 U mL−1) at 48 h and 60 h of fermentation, respectively. The extracellular tyrosinase from B. aryabhattai TFG5 was designated as TyrB. Homology modeling of TyrB revealed a structure with a predicted molecular mass of 35.23 kDa and two copper ions in the active center with its conserved residues required for the tyrosinase activity. TyrB efficiently transformed and polymerized standard phenols, such as p-cresol, p-hydroxyl benzoic acid, Levo DOPA, and 2,6 DMP, besides transforming free phenols in coir pith wash water (CWW). Additionally, UV–Vis and FT-IR spectra of the degradation products of the coir pith treated with TyrB revealed the formation of HS within 3 days of incubation. Furthermore, the E472/664 ratio of the degradation products revealed a higher degree of condensation of the aromatic carbons and the presence of more aliphatic structures in the HS. Conclusion The results confirmed the influence of TyrB for the effective synthesis of HS from coir pith wastes. The results of the present study also confirm the recently accepted theory of humification proposed by the International Humic Substances Society.

RHEOLOGICAL PROPERTIES OF HUMIC SUBSTANCES OF PEAT AND BROWN COAL

2021 ◽  
pp. 169-174
Author(s):  
Ivan I. Lishtvan ◽  
Vera N. Aleinikova
Keyword(s):  
Rheological Properties ◽  
Humic Substances ◽  
Structure Formation ◽  
Humic Substance ◽  
Brown Coal ◽  
Oil Wells ◽  
Alkaline Media ◽  
Rheological Parameters ◽  
Acid Media ◽  
Brown Coals

Knowledge about structure and rheological peculiarities of drilling solutions and reagents applied for the proceeding of oil wells has significant value for the forecasting of oil wells drilling. The research results of the structure of the humic substances of peat and brown coals precipitated in different pH ranges from the standpoint of their ability to structure formation on the base of the rheological curves obtaining of the flow of their dispersions and determining of their rheological parameters in terms of their application in drilling practice are given in the article. It is established that during transition from fraction, beset into alkaline media (12.0–8.5) to fraction beset into acid media (5.0–2.0) the decrease of the rheological indicators of caustobiolate humic substance is occurred. Rheological curves of the flow of the disperse of caustobiolate humic substances of the fraction 1 and 2 are characterized for strong fossil structures, disperses of humic substances of the fraction 3 is for less strong coagulation structures. Less structured are humic substances of brown coal so that their use is preferable for the regulation of the structure and rheological peculiarities of drilling solutions.

Use of brown coal as a detoxifier of soils contaminated with heavy metals

2018 ◽  
Vol 184 ◽  
pp. 232-238 ◽  
Author(s):  
Olga S. Bezuglova ◽  
Sergey N. Gorbov ◽  
Svetlana A. Tischenko ◽  
Anastasia E. Shimko
Keyword(s):  
Heavy Metals ◽  
Brown Coal

scholarly journals Effects of Chemical Modification on the Mechanical Properties of Calotropis Gigantea Fiber-reinforced Phenol Formaldehyde Biocomposites

2020 ◽  
Vol 26 (3) ◽  
pp. 295-299
Author(s):  
Sekar SANJEEVI ◽  
Athijayamani AYYANAR ◽  
Ramanathan KALIMUTHU ◽  
Sidhardhan SUSAIYAPPAN
Keyword(s):  
Mechanical Properties ◽  
Chemical Modification ◽  
Phenol Formaldehyde ◽  
Fiber Composites ◽  
Fiber Content ◽  
The Other ◽  
Fiber Reinforced ◽  
Calotropis Gigantea ◽  
Chemical Treatments ◽  
Treated Fiber

In this paper, the effects of three different chemical treatments on the mechanical properties of Phenol Formaldehyde (PF) composites reinforced with the Calotropis Gigantea Fibers (CGFs) were investigated based on the fiber content of the fibers. Composites were prepared by the untreated and treated fibers using the hand lay up technique and their mechanical properties were evaluated and compared. The results revealed that the composites show the greater mechanical properties at 40 wt.% for the untreated condition. Composites prepared with alkali treated fibers show the better mechanical properties as compared with the other treated fiber composites.

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