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9CHEMICAL SCIENCES
UDC. 667.612.675
STUDYING THE ELECTROKINETIC CHARACTERISTICS OF FLOCULANTS AND WASTE WATER CONTAMINATION IN THE FLOCULATION PROCESS
Ibragimova M.I.
Master student of the Department of General and Non-Organic Chemistry, Bukhara State University
St. Iqbal, Bukhara, Uzbekistan, 200118.
Abstract
Technological processes at enterprises of the textile industry are very diverse, in connection with which the concentration of impurities contained in the production of wide-ranging and industrial.
The main role in the process of flotation is played by bubbles released at the cathode (the main flotation processes flow with the participation of water). By means of electric flotation they clean the waste water of textiles. Simultaneous action on contamination of coagulants (iron or aluminum hydroxides) and gas bubbles ensures high efficiency of wastewater treatment.
Keywords: electrokinetic potential - ECP, destruction, efficiency, electroflotator, PAA - polyacrylamide, adsorption, bentonite, concentration, dye, surface-to-surface.
Waste water is formed during processing of raw materials (wool, flax, cotton), bleaching and dyeing fibers, their strengthening with adhesive substances, chemical processing and cleaning, etc. Waste water from textiles contains fiber residues, dirt particles, reagents, surface-active substances, dyes [1-2]. The
Table. 1
Permissible values of the concentration of pollutants in the composition of industrial waste water of textile enterprises discharged into water bodies
amount of pollutants in the wastewater depends on the type of fabrics produced (natural or synthetic), the color technology, the solubility of the dye reactants in the water. The characteristics of the waste water of textile enterprises are presented in table. 2.
pH COD, mg / dm3 BOD 5, mg / dm3 Suspended substances, mg / dm3 Total phosphorus, mg / dm3 Total nitrogen, mg / dm3 Ammonium nitrogen, mg / dm3 Sulfithion, mg / mg / dm3
from 6,5 to 8,5 25 160 35 3 20 10 1
A separate problem associated with the wastewater disposal of textile enterprises is their color. At the present time, more than 100 thousand types of synthetic dyes are presented on the world market with a total production of about 700,000 tons, a significant part of which are also used in textiles.
Table. 2
Average characteristics of waste water of textile enterprises
pH CPKmg BOD5, COD, Suspended Total Chromium Chlorides, Sulfides, Color,
/ dm3 mg / mg / substances, salt con- hexavalent, mg / dm3 mg / hail
dm3 dm3 / BOD 5, mg / dm3 mg / dm3 tent, mg / dm3 mg / dm3 dm3
from from from from from 15 to to 3000 from 1,0 to from to 50 from
4,0 250 to 80 to 2,2 to 8000 4,0 1000 to 50 to
to 1500 12000 5,0 1600 2500
12,0
Some of the dyes are not subject to biological decontamination, and to reduce the color of wastewater may also require the use of methods of physical and chemical cleaning.
The essence of electroflotation wastewater treatment consists in the transfer of polluting particles from the liquid to its surface with the help of gas bubbles formed during electrolysis of wastewater. Devices in which the process is produced are called electroflota-
tors. In the process of electrolysis of waste water, hydrogen is released at the cathode, and oxygen at the anode. The main role in the process of flotation is played by bubbles released at the cathode (the main flotation processes flow with the participation of water). By means of electric flotation they clean the waste water of
textiles. Simultaneous action on contamination of coagulants (iron or aluminum hydroxides) and gas bubbles ensures high efficiency of wastewater treatment. Such installations are called electroagulation-flotation. When operating electro-flotation devices, it is necessary to take into account the substantial amount of hydrogen and oxygen released during the course of the process, and take appropriate safety measures.
In the study of the adsorption of flocculants of various nature and molecular mass, the electrokinetic method showed that the negative electrokinetic potential (EKP) of particles in pollution [2].
Analogous dependences of a decrease in the negative value of the ECP of dispersed contaminants from the dose of flocculants were obtained during the floc-culation cleaning of wastewater of 1-year flow of dyeing and finishing. These results confirm the electrostatic nature of the particle-flocculant interactions for both low-molecular and high-molecular flocculants, based on the adsorbent flask. The reason for the decrease in the ECP of particles with the addition of low-molecular polyelectrolytes NaHSO3, Al2 (SO4) 3 is the adsorption of macromolecules on separate areas of the bentonite particles, which reduces the charge of these particles, which reduces the charge and reduces Such adsorption is possible, since the size of PAA polyelec-trolite macromolecules (0.075-0.1 microns) is much less than the size of particles of dispersed wastewater pollution, which usually exceeds 5 microns. A high-
molecular flocculant (PAA), the size of macromole-cules, which are used by several tens of micrometers, are adsorbed on the surface of the hour, and only a part of the amount of macromolecules is reduced.
The magnitude of the decrease in the EKP of dispersed pollution and the nature of the curves depend on the dose, type of flocculant and the composition of the waste water. Suspension of bentonite, which can be attributed to single-sided systems, and when it is processed with flocculants, a sharp decrease in the ECP of bentonite particles is observed (Table 3.). A decrease in the EKP of bentonite particles from (+48) mV to zero occurs at concentrations of the flocculant NaHSO3 0.308 g / l, Al2 (SO4) 3 0.6-1.2 g / l, significantly lower doses (1.5- 10.0 mg / l), commonly used for wastewater treatment. With a further increase in the dose of floccu-lants, the amount of ECP of bentonite particles becomes positive and grows up to a certain limiting value, which is the content of the concentration of the adsorbent density and the amount of adsorption This limiting value of the ECP was used in this work to estimate the real value of the charge of macromolecules of floccu-lants in aqueous solutions, taking into account their informative state [4].
The optimal dose of the flocculant corresponded to a certain negative value of the ECP of pollution particles, which depended on the type of flocculant and the composition of the waste water, furthermore the CLEANING was observed, the particles were as well [5].
Table. 3
Electrokinetic potential of bentonite suspension depending on the concentration of wastewater flocculants 1 -
stream
Amount of bentonite, g / l Concentration of flocculants, g / l EKP, mv
PAA NaHSO3 Al2(SO4)3
4 0,25 - - -2,0
0,5 - - +9,0
- 0,5 - -2,0
- 0,75 - +8,0
- - 0,75 -1,0
- - 1,0 +7,0
5 0,25 - - +30
0,5 - - +34
- 0,5 - +29
- 0,75 - +32
- - 0,75 +20
- - 1,0 +32
6 0,25 - - +32
0,5 - - +36
- 0,5 - +48
- 0,75 - +31
- - 0,75 +37
- - 1,0 +22
5 0,5 0,75 - +26
0,5 - 1,0 +36
0,5 0,75 1,0 +38
The degree of filling the surface with macromolecules of the flocculant (value 0) was supposed to be calculated by the formula:
0 = (EKP ref - EKP) / EKP.
Where EKP out and EKP con is the electrokinetic potential of particles in the source waste water and at a given dose of the flocculant; EKP - charge of the flocculant (the value of the EKP, corresponding to the pre-adsorption of the flocculant on the bentonite particles).
Characteristics of flocculants and dispersed measurements, are presented in table. 4 and serve for a contamination of wastewater in the process of comparative assessment of various flocculants, flocculation, obtained on the basis of electrical predicting the effectiveness of their application [6].
Table. 4.
Electrokinetic characteristics of flocculants and disperse contamination of wastewater in the process of flotation
Floculant EKP fl mV Stock type Dozaopt g / l EKPiskh, mV EKPkon, mV 0
PAA +34 1-flow 0,5 -16 -11 0,15
NaHSOs +32 1- flow 0,75 -16 -8,0 0,25
Al2(SO4)3 +32 1- flow 1,0 -16 -7,0 0,28
PAA + NaHSO3 +36 1- flow 0,5-0,75 -14 -6,0 0,22
PAA + Al2(SO4)3 +36 1- flow 0,5-1,0 -18 -7,5 0,24
NaHSO3 + Al2(SO4)3 +30 1- flow 0,75-1,0 -18 -14 0,13
PAA + NaHSO3 + Ab(SO4)s +38 1- flow 0,5-0,75-1,0 -22 -16 0,16
As follows from the analysis of the literature, the main results were obtained on the adsorption of polymers on particles of mineral dispersions. Therefore, studies
Waste water contamination, mg / l: 1-28, 2-36, 348.
The study of the kinetics of adsorption of floccu-lants on particles (Fig. 1) made it possible to substantiate the conditions for mixing the flocculant with waste water, which found an experimental confirmation [7-8]. The duration of mixing corresponds to the time of reaching the maximum amount of adsorption of macro-molecules of the flocculant on the particles of contaminants. With intensive stirring (speed gradient G = 300s-1, the maximum adsorption is reached in 0.5-1.0 hours [9].
Doses of flocculants decrease with an increase in the amount of charge or the content of ionic groups, regardless of the amount of their molecular weight.
At the same time, a higher correlation coefficient is found for the dependence of flocculant doses on the charge than on the content of ionogenic groups, which is followed by the fact that the charge of the flocculant appears as a more characteristic indicator, taking into account the timely and conformational state of macro-molecules, as well as the content of ionogenic groups in polymers.
on particles of the 1st stream, which are the most widespread contamination of wastewater from the wastewater industry.
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were carried out on the adsorption of flocculants
1 1,5 2
Time, hour.
Fig. 1. Kinetics of PAA adsorption during flotation of waste water
7. Amonova M.M., Ravshanov K.A. Polymer composition for cleaning waste water from various impurities of textile production. Izv. universities. Chemistry and chem. technology. 2019.Vol. 62. Iss. 10. P. 147-153.
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ECO-FRIENDLY WAY OF SYNTHESIS OF COPPER NANOPARTICLES
Nosovskaya E.A.,
Saint Petersburg State University of Industrial Technologies and Design 191186, Russia, Saint Petersburg, Bolshaya Morskaya, 18, Bachelor at the Department of Chemical Technologies named after
Professor Kharkharov Kudriavtseva E.V.,
Saint Petersburg State University of Industrial Technologies and Design 191186, Russia, Saint Petersburg, Bolshaya Morskaya, 18, Master at the Department of Chemical Technologies named after
Professor Kharkharov
Burinskaya A.A.
Saint Petersburg State University of Industrial Technologies and Design 191186, Russia, Saint Petersburg, Bolshaya Morskaya, 18, Associate Professor at the Department of Chemical Technologies named after Professor Kharkharov, Candidate of Engineering Sciences
ЭКОЛОГИЧНЫЕ СПОСОБЫ ПОЛУЧЕНИЯ НАНОЧАСТИЦ МЕДИ В РАСТВОРАХ
Носовская Е.А.
Санкт-Петербургский государственный университет промышленных технологий и дизайна, 191186, Санкт-Петербург, ул. Большая Морская, 18, студент бакалавриата кафедры химических технологий им. проф. А.А. Хархарова Кудрявцева Е.В.
Санкт-Петербургский государственный университет промышленных технологий и дизайна, 191186, Санкт-Петербург, ул. Большая Морская, 18, студент магистратуры кафедры химических технологий им. проф. А.А. Хархарова Буринская А.А.
Санкт-Петербургский государственный университет промышленных технологий и дизайна,
191186, Санкт-Петербург, ул. Большая Морская, 18, Доцент кафедры химических технологий им. проф. А.А. Хархарова,
кандидат технических наук
Abstract
The article discusses the issues of synthesis copper nanoparticles through reducing with ascorbic acid using eco-friendly stabilizers.
Аннотация
В статье рассмотрены способы получения наночастиц меди в растворах путем восстановления аскорбиновой кислотой с применением экологичных стабилизаторов.
Keywords: nanotechnology, nanoparticles, copper, ascorbic acid, polyvinyl alcohol, gelatin, manutex RS, antimicrobial properties.
Ключевые слова: нанотехнологии, наночастицы, медь, аскорбиновая кислота, поливиниловый спирт, желатин, манутекс RS, антибактериальные свойства.
1. Введение
В настоящее время одним из наиболее распространенных способов получения медных наночастиц является химический метод восстановления из растворов их солей. В его основе лежит химическая реакция, приводящая к образованию дисперсных
частиц определенного состава, морфологии и размеров. Основными достоинствами данного метода является простота аппаратурного оформления и экономичность, а также возможность контролировать размер образующихся наночастиц и их форму. [1-10]
