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1

Effect of bulk nanobubbles on flocculation of kaolin in the presence of cationic polyacrylamide

Sha Jie, Yuan Shuai, Chen Xinbo, Chen Wenmao, Wang Jin, Alheshibri Muidh, Bu Xiangning

Physicochemical Problems of Mineral Processing

|

2024

|

Vol. 60, iss. 2

art. no. 186729

EN

The study explores the impact of nanobubble flotation technology on fine mineral processes, focusing on its interaction with cationic polyacrylamide (CPAM) in kaolin flocculation. Nanobubbles influence particle size and promote aggregation. Experimental procedures involve bulk nanobubble preparation, kaolin suspension, and CPAM solutions, with analysis of sedimentation rates, turbidity, and zeta potential. Results show accelerated sedimentation and reduced turbidity with nanobubbles compared to traditional methods. Zeta potential measurements and DLVO theory support nanobubbles' role in reducing electrostatic interaction, facilitating flocculation. This research advances understanding in nanobubble-mediated mineral processing, highlighting eco-friendly flocculants and practical implications for optimization.

2

Chemical oxidation co-coagulation-flocculation for the flotation wastewater treatment of lead-zinc oxide ore from Lanping mine

Gong Xiang, Guo Xiulan, Li Suqi, Yuan Jiaqiao, Ding Zhan, Yu Anmei, Wen Shuming, Bai Shaojun

Physicochemical Problems of Mineral Processing

|

2024

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Vol. 60, iss. 3

art. no. 189756

EN

The flotation wastewater produced by "lead preferred flotation-zinc flotation" all-open process with aids of mixed depressants and cationic-anionic collectors has a high turbidity and multitude of reagent contaminants, and fails to meet the discharge standards. This study objective is to remove fine solid particles and flotation reagents in this wastewater by chemical oxidation cocoagulation-flocculation process. Results of chemical oxidation tests indicate peroxymonosulfate (PMS) exhibits superior performance on decreasing COD, and the COD remarkably decreases to 71.8 mg・L-1 with 100 mg・L-1 PMS addition after 120 min. Moreover, the combined oxidation of radicals (SO4•- and •OH) are responsible for degradation of flotation reagents (Na2S, DCCH, xanthates and amine) in the wastewater. Results of experimental factors confirm that the turbidity of wastewater decreases significantly from 124796 to 71.4 NTU, and the yield of water reaches above 90% with combined usage of lime (500 mg・L-1) and polyacrylamide (PAM, 50 mg・L-1). Besides, the contents of S, P, N, Zn, Pb and Fe decrease, and meet the discharge standards. Results of zeta potential analysis suggest lime reduces the electrostatic repulsion between particles, and PAM plays a bridge link role between particles, accelerating the precipitation of suspended particle.

3

Effect of pH value on effectiveness of biopolymer-based treatment of bauxite mine slurry

Meng Jian Ping, Li Shanmei, Yan Rongtao, Wei Changfu

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 3

art. no. 167949

EN

Effective dehydration and flocculation of mine slurries or sludge is important for nonferrous metal industries and environmental engineering. However, the mechanisms for the flocculation of slurry remain largely unclear. This paper presents the results of a series of flocculation tests, which was conducted on the slurry suspensions treated by xanthan gum (flocculant) at different pH values. It is shown that the settlement rate of mine slurry particles can be accelerated by adding xanthan gum, and the maximum sedimentation rate was obtained at a pH value of 5.9, and the final volume of flocs is significantly increased due to the addition of the flocculant. In addition, the settlement rates of xanthan gum-treated slurry suspensions at the pH values of 3, 5 and 7 decrease slightly compared with the reference slurry suspensions with pH=5.9, and the slurries remained stable as suspensions at the pH value of 9 and 11. The zeta potential measurement and SEM image analysis show that flocculation occurs primarily due to electrostatic attraction between slurry particles and the flocculants, and the bridging effect between the carboxylic groups in the side chains of xanthan gum molecule and the suspension particles.

4

About impact of clogging phenomena on well productivity

Sultanova Arzu V., Mammadov Ramil M.

Nafta-Gaz

|

2023

|

R. 79, nr 1

20--27

PL

During the opening of a productive formation by drilling, penetration of clay particles from the drilling fluid into the leading filtration channels of the rock occurs. As a rule, productive formations are opened at pressures that are significantly higher than the formation pressure. The amount of hydrostatic repression depends on the density of the drilling fluid, the height of the liquid column, and the reservoir pressure. A classic example of the latter is the problem of studying changes in reservoir properties that occur at the drilling stage, where relatively small particles of drilling fluid penetrate along with the flow into the pore space. A decrease in the bottomhole zone permeability in oil wells leads to a significant decrease in oil production rates, and sometimes to their complete stop, which ultimately significantly affects the total oil recovery and economic indicators of the oil fields’ development. The decrease in permeability can be caused by many factors: • clogging of the bottomhole zone of the productive formation in the process of drilling a well; • formation of a crust in perforated channels during cumulative perforation; • colmatation of the bottomhole zone of the productive formation during the operation of the well; • clogging of perforated channels during well killing and subsequent clogging; • formation of deposits of paraffins and asphaltenes in the pores of the rock of the bottomhole zone of the well. Bottomhole zone damage (clogging) significantly affects the productivity of wells, and the permeability of the formation, determined by the results of hydrodynamic studies. At the same time, clogging is understood as damage of the bottomhole zone with drilling fluid when opening the productive formation, and deterioration of the properties of the bottomhole zone during cementing, perforation of the productive interval, swelling of clays, etc. This paper presents an analysis of laboratory and field studies of the influence of clogging on the productivity of wells when opening layers with different capacitive and filtration properties, and also provides an analytical estimation of this effect, both for vertical and horizontal wells.

EN

W czasie udostępniania formacji produktywnej poprzez wiercenie następuje przenikanie cząstek ilastych z płuczki wiertniczej do przestrzeni porowej skały. Formacje produktywne są z reguły udostępniane przy ciśnieniach, które są znacząco wyższe niż ciśnienia złożowe. Wielkość przeciwciśnienia hydrostatycznego zależy od gęstości płuczki wiertniczej, wysokości słupa cieczy oraz ciśnienia złożowego. Klasycznym przykładem tego ostatniego jest problem badania zmian właściwości zbiornikowych na etapie wiercenia, kiedy to stosunkowo niewielkie cząstki ilaste przenikają, wraz z płuczką wiertniczą, do przestrzeni porowej. Spadek przepuszczalności w strefie dennej odwiertów naftowych prowadzi do znaczącego spadku wydajności produkcji ropy, a czasem nawet do całkowitego zatrzymania wydobycia, co ostatecznie znacząco wpływa na wielkość całkowitego wydobycia ropy oraz wskaźniki ekonomiczne udostępnienia złoża ropy. Spadek przepuszczalności może być spowodowany wieloma czynnikami: • kolmatacją strefy dennej w obrębie formacji produktywnej na etapie wiercenia otworu; • tworzeniem się warstwy osadu w perforowanych kanałach podczas skumulowanej perforacji; • kolmatacją strefy dennej formacji produktywnej w czasie eksploatacji odwiertu; • blokowaniem kanałów perforacyjnych w czasie zatłaczania odwiertu i później; • tworzeniem się osadów parafin i asfaltenów w porach skały w strefie dennej odwiertu. Uszkodzenie strefy dennej odwiertu znacząco wpływa na wydajność odwiertów oraz przepuszczalność formacji złożowej, określoną przez wyniki badań hydrodynamicznych. Uszkodzenie jest jednocześnie rozumiane jako zanieczyszczenie strefy dennej płuczką wiertniczą przy udostępnianiu formacji produktywnej, pogorszenie się właściwości w strefie dennej w czasie cementowania lub perforacji interwału złożowego, pęcznienie iłowców, itp.

5

Research on closed-loop utilization of engineering waste mud in engineering sites

Zhan Jinsheng, Zhao Shichun

Materials Science Poland

|

2023

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Vol. 41, No. 3

99--110

EN

The large amount of waste mud generated during construction projects makes it difficult to implement closed-loop on-site treatment, resulting in the inability to achieve zero emissions, which not only wastes land resources but also pollutes the environment. This article first studied the flocculation effect and mechanism of two flocculants. Then, the treated sediment was used to prepare fluidized solidified soil, and the effect of flocculants in the sediment on the performance of fluidized solidified soil was studied. Finally, this technology of flocculation and re-solidification was applied in engineering. The results showed that the composite effect of adding PAC flocculant first and then APAM flocculant in the mud had the best mud-water separation effect. The soil was combined with the flocculants to prepare fluidized solidified soil that can effectively improve the strength and water stability of the solidified soil. Through engineering applications, it has been proven that closed-loop utilization of engineering waste mud can be achieved on-site. Therefore, this work provides a new method for achieving zero emissions through closed-loop utilization of engineering waste mud on-site and innovative experience for the construction of "waste-free cities".

6

Natural coagulation as an alternative to raw water treatment

Villabona-Ortíz Ángel, Tejada-Tovar Candelaria, Ortega-Toro Rodrigo, Licona Dager Natalia, Millan Anibal Marta

Journal of Water and Land Development

|

2023

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no. 56

21--26

EN

The availability of drinking water is one of the several problems humans face, considering that its availability is reduced to 0.80% of the existing fresh water. Then, coagulation-flocculation is a stage of this treatment. It is a process that agglomerates the suspended particles in a larger (floc) that could be separated by sedimentation and filtration processes to make the water drinkable. So, this work aimed to evaluate the effect of the dose of coagulant of yam starch (Dioscorea rotundata) and the speed of agitation in the turbid water treatment process. For which the yam starch was extracted by implementing two methods which were NaOH and H2O, using centrifugation at 1500 rpm for 10 min, and adjusting the pH with HCl and NaOH 0.20 M, for later determining the effect of agitation speed (rpm) and coagulant concentration (ppm) on the percentage of turbidity removal, pH, and colour, to be compared with a synthetic coagulant. A yield of 42.60% was found in the wet base. The natural coagulants extracted with NaOH presented better turbidity removal, with a percentage of 92.48% at an agitation speed of 40 rpm and a concentration of 250 ppm. It can be concluded that natural yam coagulant can be recommended for use in the coagulation stage in the raw water treatment process for subsequent conversion to drinking water.

7

Tetracycline Remove from Synthetic Wastewater by Using Several Methods

Al-Kindi Ghayda Yaseen, Alnasrawy Shaimaa Taleb

Journal of Ecological Engineering

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2022

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Vol. 23, nr 5

137--148

EN

Tetracycline (TC), a commonly utilized drug for human and animal therapy, is one of the most widespread antibiotic residues existing in the environment. The lack of sophisticated techniques for the removal of residual tetracycline from wastewater indicates an actual environmental risk. In this study, three methods for tetracycline removal from synthetic wastewater were utilized. Pillared clay was used as adsorbent (alone) and with coagulant (alum) in a hybrid technique. Coagulation and flocculation technique was the first method. The best operation conditions were alum dose of 2.5 mg/L, pH 7 and tetracycline concentration of 10 mg/L. The second method was the adsorption on Al-Fe pillared clay, the optimum operating conditions were found to be pH 4.5, time 120 minutes, tetracycline dose 90 mg/L, and the amount of Al-Fe pillared clay adsorbent 400 mg/L. In the third method (hybrid method), the optimum conditions for the above methods were used. The highest removal efficiency of tetracycline by using coagulation and flocculation only as a coagulant reached 60%. In turn, by using Al-Fe pillared clay it was 90% and in the case of the hybrid method, it was 94%. Thus, the hybrid technique improves the removal of tetracycline from synthesized wastewater.

8

PAC adsorption efficiencies in the filter and in the homogeneous flocculator. A full-scale comparative study

Bielski Andrzej

Environment Protection Engineering

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2022

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Vol. 48, nr 1

83--97

EN

The paper investigates the efficiency of adsorption of organic pollutants present in natural water on powdered activated carbon (PAC). A PAC adsorption capacity is related to the mass exchange driving force between water and sorbent. During the study, it was confirmed that the mass transfer driving force in the homogeneous flocculator with simultaneous PAC adsorption was lower than in the filter column. The filter showed a better utilization of PAC adsorption capacity than the volume system, for the optimal PAC dose. The authors proposed a new method where adsorption was carried out in the filter column with PAC applied to its upper layer. The powdered sorbent was applied to the bed at the end of a backwashing cycle. Two models of PAC adsorption in transient states for the homogeneous flocculator and the column mass exchanger were presented. The simulation calculations confirmed that there was still a possibility to double the PAC adsorption capacity concerning commonly used adsorption with coagulation in the homogeneous flocculator.

9

Study of the Operation of an Industrial Water Treatment Plant of the Northern Soft Drink Company Fez, Morocco

Elmansouri Ibtissame, Lahkimi Amal, Mansour Omar, Elouadrhiri Faical, Chaouch Mehdi, Eloutassi Noureddine, Elkhamar Fehmi, Bekkari Hicham

Ecological Engineering & Environmental Technology

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2022

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Vol. 23, iss. 6

227--232

EN

In order to verify the operation of the NSDC company’s industrial water treatment plant and to optimize the quality of the liquid discharges by coagulation and flocculation, we carried out the physico-chemical characterization of these liquid discharges and optimized the elimination of the organic matter. The results show that the abatement rate of the parameters SM, COD and BOD5 of the step are respectively 67%, 66% and 89% during November 79% 81% 89% during December and 69% 82% 89% during January. The treated wastewater showed that the WWTP is working properly, but in the coagulation flocculation treatment step instead of using a large amount of Dekfloc alone. We tried to optimize the dose of a plant powder as bio flocculant injected with Dekfloc as coagulant, which will increase the removal rate of organic matter. The tests of coagulation flocculation show that the application of the combination between Dekfloc and the powder of the cactus allows to increase the rate of abatement of COD to 54%, of BOD5 to 67%, of TSS to 80%, and therefore the reduction of microorganisms.

10

Flocculation Process of Yeast Brewers®

Kucharczyk Krzysztof, Tuszyński Tadeusz, Żyła Krzysztof

Postępy Techniki Przetwórstwa Spożywczego

|

2021

|

nr 1

120--123

EN

Yeast flocculation is a reversible, asexual and calciumdependent process by which cells stick to form flocs of thousands of cells. After the formation of a larger cell conglomerate, there is a massive separation from the medium by sedimentation of the bottom fermenting yeast. The ability to flocculate yeast cells is of great importance to the brewing industry as it effectively separates the yeast cell from the green beer at the end of fermentation. Therefore, a strong and complete flocculation property of the brewer’s yeast is desired. However, yeast cells should not flocculate too quickly until the wort is completely fermented as premature flocculation slows down fermentation and can also lead to inappropriate volatile components. Therefore, ideal brewer’s yeast should flocculate strongly towards the end of fermentation. This flocculation should also be constant in subsequent fermentations. The phenomenon of flocculation is a complex process influenced by biochemical, genetic and physical mechanisms.

PL

Flokulacja drożdży jest odwracalnym, bezpłciowym i zależnym od zawartości wapnia procesem, w którym komórki przylegają, tworząc kłaczki składające się z tysięcy komórek. Po utworzeniu większego konglomeratu komórek, następuje masowe oddzielenie od podłoża przez sedymentację drożdży dolnej fermentacji. Umiejętność flokulacji komórek drożdży ma duże znaczenie dla branży piwowarskiej, ponieważ zapewnia w skuteczny sposób oddzielanie komórkę drożdży z zielonego piwa pod koniec fermentacji – dlatego pożądana jest silna i pełna właściwość flokulacji drożdży piwowarskich. Komórki drożdży nie powinny jednak zbyt szybko flokulować, zanim brzeczka nie będzie całkowicie odfermentowana, gdyż przedwczesna flokulacja powoduje spowolnienie fermentacji, a także może prowadzić do uzyskania niewłaściwych zawartości lotnych komponentów. Idealne drożdże piwne powinny się charakteryzować silną flokulacją pod koniec fermentacji i powinna ona być również stała w kolejnych fermentacjach. Zjawisko flokulacji jest procesem złożonym, na które mają wpływ mechanizmy biochemiczne, genetyczne i fizyczne.

11

Application of low-field NMR in the study of flocculant-aided filtration process of coal tailings

Guo Zhimin, Liang Long, Hu Pengfei

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 3

1--7

EN

Preconditioning of coal tailings with flocculants is a useful technology to improve filtration performance. In this study, anionic and cationic polyacrylamides were used for the pretreatment coal tailings before filtration. Nondestructive and rapid measurement of the filter cakes of coal tailings at different filtration stages was conducted using a nuclear magnetic resonance (NMR). The transverse relaxation time (T2) results of NMR provided the information concerned the state of water in filter cake, showing that free water entrapped in larger pores was removed mainly during coal tailings filtration, and the pressure in this study cannot remove the inherent moisture of filter cake of coal tailings. The significant increase in the amplitude of T2 value between 0.1 and 1.0 ms revealed that the flocs collapsed into smaller ones with water entrapped in them during filtration. Comparing the NMR results with different flocculants shows that anionic polyacrylamide of 800 g/Mg produced a larger structure in the initial stage of filter cake formation. The final filter cake entrapped more water. The NMR results well validated the filtration experiments.

12

Evaluation of the Potential of Opuntia Ficus-Indica Cladodes as a Natural Flocculant for Wastewater Treatment through Simple Procedures

Trindade Sofia, Rouxinol Maria Inês, Nabais João, Agulheiro-Santos Ana Cristina

Journal of Ecological Engineering

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2021

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Vol. 22, nr 5

249--257

EN

Nowadays there is a search for new alternatives to replace harsh and expensive chemical methods to wastewater treatments. The common methods include the usage of chemicals that negatively affect the environment and the human health. The cladodes of Opuntia ficus-indica (L.) Mill have a great potential for use in innovative, cheap, renewable and eco-friendly water treatment due to their flocculant properties. In this work, different water treatments including fresh cladodes, lyophilized cladodes and the material obtained through mucilage extraction were tested. The turbidity of the water was measured, and it was concluded that the use of 60 g of small pieces of fresh cut cladodes was the method with the best results, reaching 4 NTU of turbidity. It confirmed the ability of O. ficus-indica (L.) Mill cladodes to promote the flocculation of clay in water, enabling to turn the unused material waste into a useful raw material.

13

Separation of phosphoric acid sludge: effect of flocculation on settling and P2O5 recovery rates

Jouraiphy Rim, Anouar Islaam, Mazouz Hamid, Mendil Jihane, Ibnlfassi Amina

Physicochemical Problems of Mineral Processing

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2020

|

Vol. 56, iss. 5

759--771

EN

Phosphoric acid sludge is one of the prominent problems in the phosphate industry. Its formation is co-occurred by considerable losses of P2O5 that affect the process performance. Management and valorization of this waste is a key issue. This work aimed to deal with this industrial concern by studying the influence of the flocculation on the sludge sedimentation and thus the P2O5 recovery rate. The flocculation tests were conducted in the presence of various types of anionic polymers. The effect of dosage, molecular weight, and type of flocculant were examined. The results indicated that all polymers showed settling performance improvement. And, the flocculant with the highest molecular weight (F1), showed the best settling performance with a pace of 3.3 cm/min and the lowest turbidity value of 40.4 NTU using a dosage of 5 ppm. Due to its high molecular weight, this polymer carries a polyelectrolyte bridging mechanism, which allows the absorbed polymer to move further away from the surface of the particle and then increases the particle radius, the number of collisions, and thus the particle size. However, for the P2O5 recovery rate, the sulfonic polymer (F5) was the best performer allowing recovery of 78.8% of the total mass of the sludge. F5 is weakly amphoteric. Polymers containing sulfonic acid groups are known to be inherently powerful than the carboxylic acid groups as they are stable due to their high energy barrier. According to the results, the flocculation increases the recovery of P2O5, which represents a profit of more than 30 kg of clarified phosphoric acid per 1 tone of sludge.

14

Investigation of flocculation properties and floc structure of coal processing plant tailings in the presence of monovalent and divalent ions

Gungoren Can, Unver Ilgin Kursun, Ozdemir Orhan

Physicochemical Problems of Mineral Processing

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2020

|

Vol. 56, iss. 5

747--758

EN

Low-rank coals are generally processed with wet methods including washing, flotation, etc. Fine-sized tailings of these processes are discharged to tailing ponds with a significant amount of associated water which contains a high amount of dissolved ions. These tailings should be dewatered employing coagulation/flocculation in terms of technological and environmental aspects. In this study, the coagulation/flocculation behavior of coal processing plant tailings obtained from Manisa, Turkey was investigated in the presence of monovalent (Na+, K+) and divalent (Mg2+, Ca2+) ions and an anionic flocculant (SPP-600). First, the coagulation properties of coal tailings were determined. Then, the flocculation experiments were carried out, and the turbidity values of the suspensions were measured. Moreover, the sizes of the flocs were determined using a laser diffraction particle size analyzer to analyze the strength of the flocs. The results of the coagulation experiments showed that while divalent ions were more effective at 10-1 mol/dm3, higher settling rate and lower turbidity values were obtained in the presence of monovalent ions at 1 mol/dm3 concentration. The optimum flocculant dosage was obtained as 150 g/Mg from the flocculation experiments. The floc size and strength measurements indicated that the larger flocs were obtained with Na+ than Ca2+ in the presence of the flocculant. The strongest flocs were obtained at 10-1 mol/dm3 Ca2+ + 150 g/Mg flocculant. It can be concluded from this study that the coagulation followed by the flocculation method can be employed to obtain fast flocculation behavior and low turbidity for the dewatering of coal tailings.

15

Structural modification of cellulose to enhance the flotation efficiency of fine copper oxide ore

Gu Guohua, Zhu Renfeng, Chen Zhixiang

Physicochemical Problems of Mineral Processing

|

2019

|

Vol. 55, iss. 1

58--69

EN

Using more efficient collector to improve the recovery efficiency of fine copper oxide has become imperative as the shortage of copper mineral resources. In this study, the new collector 3-hydroxy butyrate-carboxy methyl cellulose xanthate (HCMCX) was synthesized by carboxy methyl cellulose, 3-hydroxy butyrate and carbon disulfide, all of which as raw materials . The structural characteristics of HCMCX was detected by both infrared spectrum and ultraviolet spectrum. Besides, the interacting behavior between HCMCX and fine malachite was investigated through particle size analysis, contact angle measurements, and flotation tests. Particle size analysis indicated that the mean size of malachite was increased by 8 μm while the HCMCX concentration at 200 mg/dm3. The contact angle measurements demonstrated that, comparing with the collector AX at a same dosage, the mineral surface of malachite showed a stronger hydrophobicity after interacting with HCMCX. Microflotation tests results exhibited that the recovery of malachite was about 94% when the pulp pH 8 and collector concentration at 200 mg/dm3. The results of practical ore flotation tests showed that HCMCX could as an excellent collector for flotation of fine malachite, finally to achieve the concentrates containing 20% Cu and 88% Cu recovery.

16

Symulacja procesu powstawania agregatów podczas flokulacji domieszek wód powierzchniowych

Rybachuk Yurii, Jodłowski Andrzej

Inżynieria i Ochrona Środowiska

|

2019

|

T. 22, nr 1

42--52

EN

The main aim of the article is to analyse physical and chemical factors affecting the structure and strength of aggregates generated during coagulation and flocculation of water admixtures in the aspect of computer process simulation. The proposed mathematical relationships were used for computer modelling of the process and visualization of the obtained results. The results of the operation and visualization of the algorithms are presented in graphical form. Laboratory tests were carried out in order to check the correctness of the proposed algorithm.

PL

Głównym celem artykułu jest analiza czynników fizycznych i chemicznych wpływających na strukturę i wytrzymałość agregatów powstających podczas koagulacji i flokulacji domieszek wody w aspekcie komputerowej symulacji procesu. Zaproponowane zależności matematyczne wykorzystano do komputerowego modelowania procesu oraz wizualizacji uzyskanych wyników. Wyniki działania i wizualizacji algorytmów przedstawiono w formie graficznej. W celu sprawdzenia poprawności proponowanego algorytmu przeprowadzono badania laboratoryjne.

17

Model matematyczny procesu koagulacji/flotacji ciśnieniowej (DAF) oparty na prawie zachowania pędu

Rybachuk Yurii, Jodłowski Andrzej

Inżynieria i Ochrona Środowiska

|

2019

|

T. 22, nr 1

75--87

EN

The launch of new pressure flotation installations (DAF) and the optimization of existing installations of this type requires a number of laboratory and pilot plant tests. Such studies are expensive and labor-intensive. Using the principles of computer modelling it would be possible to minimize both costs and time of conducting research. This paper presents a proposal to use the developed mathematical model of the DAF process based on the law of conservation of momentum (impulse) and the Navier-Stokes equation. The model allows to describe the kinetic relations between the water stream, air bubbles and aggregates arising as a result of coagulation of surface water pollution. The model takes into account the exchange of impulses between different phases as a result of laminar and turbulent flow. The developed model was used to prepare a simulation computer program. In order to check the applicability of the model, laboratory tests were carried out under static conditions, the results of which demonstrated the suitability of the model for analyzing the effectiveness of solid phase removal from water in the coagulation/dissolved air flotation process used in surface water treatment.

PL

Uruchomienie nowych instalacji flotacji ciśnieniowej (DAF) i optymalizacja już istniejących instalacji tego rodzaju wymaga przeprowadzenia szeregu badań laboratoryjnych i pilotowych. Takie badania są kosztowne i pracochłonne. Wykorzystując zasady modelowania matematycznego, można zminimalizować zarówno koszty, jak i czas prowadzenia badań. W niniejszej pracy przedstawiono propozycję wykorzystania opracowanego modelu matematycznego procesu DAF w oparciu o prawo zachowania pędu (impulsu) i równania Naviera-Stokesa. Model pozwala opisać relacje kinetyczne pomiędzy strumieniem wody, pęcherzykami powietrza i agregatami powstającymi w wyniku koagulacji zanieczyszczeń wód powierzchniowych. Model uwzględnia wymianę impulsów między różnymi fazami w wyniku przepływu laminarnego i turbulentnego. Opracowany model posłużył do przygotowania symulacyjnego programu komputerowego. W celu sprawdzenia aplikacyjności modelu przeprowadzono testy laboratoryjne w warunkach statycznych, których wyniki wykazały przydatność modelu do analizy skuteczności usuwania fazy stałej z wody w procesie koagulacja//flotacja ciśnieniowa wykorzystywanym w uzdatnianiu wód powierzchniowych.

18

Reuse of alum sludge for reducing flocculant addition in water treatment plants

Scalize Paulo S., Souza Leonora M. D., Albuquerque Antonio

Environment Protection Engineering

|

2019

|

Vol. 45, nr 1

57--70

EN

The recycling of water treatment residues (WTR) inside drinking water treatment plants (DWTP) to be a good option for reusing this type of waste, as well as for reducing the costs with its disposal off and with the acquisition of treatment chemicals. Therefore, a WTR was reused for auxiliary of the coagulation-flocculation processes for reducing the use of aluminium sulfate (coagulant) in a DWTP. Three series of experiments have been conducted involving three water samples with different turbidity and colour, different WTR samples with different total suspended solids (TSS) concentrations and different aluminium sulfate concentrations. The results showed that WTR can efficiently be used for the removal of turbidity between 21 NTU and 218 NTU and colour between 194 HU and 1509 HU for TSS concentration between 1635 mg/dm3 and 5420 mg/dm3, with better results in the range between 1635 mg/dm3 and 2678 mg/dm3. For higher TSS concentrations, the removal of both parameters decrease because there are excess of organics released to water, which demands the use of more coagulant.

19

Wielkość cząstek wodorotlenku żelaza powstającego w procesie koagulacji koagulantami żelazowymi

Bray R. T., Fitobór K.

Technologia Wody

|

2018

|

Nr 3 (59)

16--21

PL

Celem pracy było wykorzystanie granulometru laserowego do pomiaru wielkości cząstek powstających w procesie koagulacji z zastosowaniem koagulantów żelazowych w wodzie niezawierającej znacznych ilości substancji organicznych. Badania przeprowadzono z wykorzystaniem wody wodociągowej pochodzącej z ujęć podziemnych. Do wody dozowano koagulant żelazowy PIX112 (siarczan żelaza(III) – Fe2(SO4)3) w dawkach o 2,0 do 10 mg Fe/dm3. Już w kilka sekund po dozowaniu koagulantu w wodzie pojawiały się drobne cząstki o wymiarach od 0,03 µm do ok 0,5 µm. Następnie następował stały wzrost wielkości kłaczków, do rozmiarów około 130÷500 µm, przy którym proces osiągał stan ustalony. Prędkość zwiększania się wymiarów kłaczków oraz czas, po którym kłaczki osiągały maksymalne rozmiary, był zależny od dawki siarczanu żelaza. Wraz ze zwiększaniem dawki koagulantu kłaczki szybciej powiększały swoje wymiary i szybciej osiągały maksymalne rozmiary. Pomimo systematycznego wzrostu kłaczków w początkowym okresie, w roztworze nadal utrzymywały się najdrobniejsze cząstki, które stopniowo wbudowywane były w większe aglomeraty. Proces ten trwał od kilku sekund do kilku minut i był zależny od dawki koagulantu. Im mniejsza była dawka, tym dłuższy był czas utrzymywania się najmniejszych cząstek.

EN

The aim of the work was to use a laser granulometer to measure the size of particles produced by coagulation using ferric coagulants in water containing no significant amounts of organic substances. The research was carried out using tap water, coming from underground water intakes. PIX112 coagulant was dosed into the water at doses of 2.0 to 10 mg Fe/dm3. Already a few seconds after dosing the coagulant, small particles of size from 0.03 μm to about 0.5 μm appeared in the water. Then there was a constant increase in the size of flocks, to the size of about 130÷500 μm, at which the process reached steady state. The rate of increase in the size of the flocs and the time after which the flocs reached the maximum size was dependent on the dose of iron sulphate. With increasing the dose of coagulant, the floccules increased their size faster and reached their maximum sizes faster. Despite the systematic growth of flocs in the initial period, the smallest particles, which were gradually incorporated into larger agglomerates, still remained in the solution. The process lasted from a few seconds to several minutes and was dependent on the dose of the coagulant. The smaller the dose, the longer the time of maintaining the smallest particles.

20

Laboratoryjne badania sedymentacji wielostrumieniowej zawiesin nieziarnistych

Banaś M.

Przemysł Chemiczny

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2018

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T. 97, nr 9

1453--1455

PL

Przedstawiono wyniki badań procesu sedymentacji zawiesin nieziarnistych z koagulacji drobnouziarnionych zawiesin reprezentatywnych dla wód ujmowanych do stacji uzdatniania wody. Zaprezentowano wpływ zmiany obciążenia powierzchniowego zawiesin skoagulowanych różnymi dawkami flokulantów i wykazano skuteczność techniki sedymentacji wielostrumieniowej dla klarowania takich właśnie zawiesin. Wykazano przydatność techniki sedymentacji wielostrumieniowej również dla zawiesin nieziarnistych.

EN

Two non-granular slurries were prepd. by mixing silty and clay soils with water and then sepd. by sedimentation after addn. of an Al flocculant (15-65 ppm). The removal of solids from the suspensions was higher than 75%. The turbidity of the purified water was below 20 NTU.