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Analiza wybranych konstrukcji wielozłożowego adsorpcyjnego układu chłodniczego

Neska Mirosław, Opara Tadeusz, Majcher Andrzej

Przemysł Chemiczny

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2024

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T. 103, nr 1

73--78

PL

Omówiono budowę i funkcjonowanie prostego, jednozłożowego adsorpcyjnego układu chłodniczego. Dokonano analizy wybranych konstrukcji układów wielozłożowych. Zweryfikowano opracowany prototyp własnego rozwiązania systemu adsorpcyjnego. Zaprezentowano przykładowe wyniki z weryfikacji układu, dla którego osiągnięto temperaturę w parowniku na poziomie ok. 6°C. Innowacyjnym elementem tego układu był kształt prototypowych adsorberów ze stali nierdzewnej, które są wykonane jako dwa różne rozwiązania konstrukcyjne: walcowo-krzyżowy i walcowo-rurowy. Prezentowane systemy adsorpcyjne, ze względu na swoje parametry pracy, mogą być wykorzystywane do zagospodarowania niskotemperaturowego ciepła odpadowego w przemyśle.

EN

The construction and operation of a simple single-bed adsorption refrigeration system were discussed. Selected designs of multi-bed systems were analyzed. A verified prototype of our own soln. of a threebed adsorption refrigeration system was presented. Examples of results from the verification of the system for which the temp. in the evaporator was reached at the level of approx. 6°C were presented. An innovative element of the system was the shape of the prototype stainless steel adsorbers, which were made in 2 different design solns.: cylindrical-cross and cylindrical-tube. Due to their operational parameters, the presented adsorption systems can be used for the management of low-temp. waste heat in industry.

2

CO2 bubble formation on dolomite surface and its influence on surface wettability and flotation of dolomite

Li Xianbo, Zhang Qin, Chen Aoao, Wang Xuming

Physicochemical Problems of Mineral Processing

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2024

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Vol. 60, iss. 3

art. no. 190254

EN

Dolomite is a common carbonate mineral that can release CO2 gas under acidic conditions. The formation of bubbles on the dolomite surface might play a critical role in the flotation separation of dolomite from apatite. In this study, the CO2 bubbles formation due to CO2 gas releasing from the dolomite surface under acidic condition was observed using an atomic force microscope (AFM). The influence of CO2 bubbles on flotation behavior and surface wettability of dolomite was evaluated through micro-flotation test, contact angle measurement and molecular dynamics simulation. The results indicate that no gas phase points were observed on the dolomite surface in deionized water or sodium oleate (NaOL) solution. CO2 nanobubbles were observed on the dolomite surface treated with NaOL solution at pH 5, with an average size of 44 nm. The presence of CO2 gas layers has a shielding effect on the adsorption of water molecules on the dolomite surface, potentially enhancing the surface hydrophobicity of dolomite. Therefore, CO2 bubbles are beneficial for improving flotation recovery of dolomite. This study inspires the idea of utilizing the released CO2 bubbles in the flotation process of dolomite.

3

Adsorption and desorption characteristics of rare earth ions on halloysite surfaces

Long Qibang, Yan Huashan, Zhou Xiaowen, Qiu Sen, Qiu Tingsheng

Physicochemical Problems of Mineral Processing

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2024

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Vol. 60, iss. 1

art. no. 185763

EN

Rare earths (REs) are primarily adsorbed in ionic form on the surface of clay minerals such as halloysite in ionic rare earth ores. As a result, understanding the adsorption and desorption behaviors of RE ions on the surface of the halloysite may contribute to clarifying the mineralization process of ionic rare earth ores and provide a theoretical framework for the optimization of the extraction process. The adsorption and desorption characteristics of light (Nd3+), medium (Eu3+), and heavy (Lu3+) RE ions on the surface of halloysite-10 Å were comprehensively examined in this study. Because REs are more inclined to form an outer layer and inner layer adsorption when halloysite is protonated and deprotonated with the range of pH, respectively, pH has a significant impact on how halloysite adsorbs and desorbs. The experiment findings indicate that RE concentration, duration, and pH all increased the adsorption capacity of light, medium, and heavy REEs, and exhibited some selectivity for heavy REEs. Nd3+, Eu3+ and Lu3+ ions adsorption processes on the surface of Halloysite-10 Å are consistent with the Langmuir isothermal adsorption model and pseudo-second-order kinetic equations. The desorption efficiency of Lu3+ decreases dramatically with increasing pH due to hydrolysis and more inner layer adsorption than that of Nd3+ and Eu3+.

4

Removal of Heavy Metals from Textile Wastewater Using a Mixture of Carbon from Bare Hands and Carbide Waste as an Adsorbent

Karim Muhammad Arief, Yuniar Henny, Lestari Chelsie Camari, Widowati Tri Wardani

Journal of Ecological Engineering

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2024

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Vol. 25, nr 1

245--255

EN

Heavy metal pollution, mainly originating from textile waste containing synthetic dyes and stabilizers such as Fe, alum, and lime, poses serious risks to health and the environment. To overcome this problem, this research explores the use of activated carbon for heavy metal reduction. Empty palm oil fruit bunches (EFB) offer a promising source of activated carbon due to their high lignocellulose content and functional groups (-OH and -COOH) that enhance heavy metal adsorption. In addition, carbide waste, which is classified as hazardous and toxic waste, poses an ecological threat if disposed of incorrectly. This research focuses on the use of EFB waste and carbide to reduce Fe metal in Fe metal synthesis waste. Various adsorbent ratios (2:2.5, 2.5:2, and 2.5:2.5) and contact times ranging from 30 to 150 min were investigated, with an initial metal synthesis waste concentration of 40 mg/L. The findings showed that longer contact times resulted in the removal of large amounts of Fe(II) metal, with rates reaching 94.325%. The increase in the pH of the adsorbent mixture is caused by the alkaline nature of carbide waste in activated carbon. The Langmuir isotherm model provided the best fit to the data, with a correlation Equation of y = 0.3882x + 1.4823 (R2 = 0.995, RL = 0.556), which shows the effectiveness of the TKS-carbide waste mixture in reducing Fe(II) ions in the waste textile. The Freundlich isotherm model also showed a reasonable fit, with a correlation equation of y = -0.2804x – 0.0133 (R2 = 0.95). In summary, EFB-carbide waste adsorbent is a successful, consistent, and environmentally friendly solution for the reduction of heavy metals in textile waste.

5

Elimination of Hexavalent Chromium Ions in Water Using a Manganese-Coated Pumice Adsorbent

Lestari Puji, Purwiandono Gani, Pramayshela Shike, Siswoyo Eko

Journal of Ecological Engineering

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2024

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Vol. 25, nr 1

229--235

EN

A natural pumice stone stone coated with manganese (Mn) has been prepared and utilized to remove hexavalent chromium (Cr(VI)) ions in water via adsorption process. Prior to the application, the natural pumice was ground, sieved, and immerse in a dilute HCl solution. The coating of Mn on the acid-activated pumice was carried out by soaking the powder in 0.5 M Mn(NO3)2 solution for 72 h. The characterisation of the produced pumice adsorbent was performed with scanning electron microscopy and fourier-transform infrared spectroscopy instruments. The adsorption of Cr(VI) onto Mn-coated pumices was optimum at pH 3. Both the Langmuir and Freundlich isotherm models could be used to describe the adsorption process. The rate of adsorption followed the model for pseudo- second-order kinetics. The maximum adsorption capacity of Mn-coated pumice towards Cr(VI) ions was 1.94 mg/g.

6

Decolorization of Cationic Dye from Aqueous Solution by Multiwalled Carbon Nanotubes

Ahmed Salwa H., Rasheed Ekehwanh A., Rasheed Luma A., Abdulrahim Firas R.

Journal of Ecological Engineering

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2024

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Vol. 25, nr 2

72--84

EN

Methylene blue is a synthetic and cationic dye that finds utility in different fields including pharmaceutical, paper, textile, printing, carpet, and photography industries. Adsorption is a very effective technique to decolorize contaminated wastewater. This study aimed to determine the efficacy of Multiwalled Carbon Nanotubes (MWCNTs) as an adsorbent for decolorization of MB dye from aqueous solutions. The study examined various characteristics affecting adsorption, including concentration of dye, pH value, dosage of MWCNTs, and contact time. The results that growing the adsorbent dosage from (25 to 120) mg increased the dye efficiency rate from 62% to 98%, respectively, were shown. The study also evaluated pH, which is among the most critical factors influencing removal efficiency. The best pH for the removal efficiency was 6 at an initial concentration of MB dye 20 mgL-1, a contact time 60 min, and an MWCNT dosage 100 mg. Langmuir, Freundlich, and Temkin isotherms were used to describe the adsorption equilibrium. The Langmuir isotherm with an R2 value of 0.9968 and a maximum capacity for adsorption of 19.6 mgg-1 provided a suitable fit for the data of the experiment. In comparison between the suitability of kinetic models pseudo-first-order, pseudo-second order, and Weber–Morris, the kinetics model’s correlation value was shown to be greater than that of the pseudo-second order kinetic model with an R2 value of 0.9982.

7

Comparative study on the adsorption of lead ions by kaolin loaded chitosan by different modification methods

Zhang Shuqin, Boyue Yuan, Liu Yi, Zhang Kening, Ren Dajun, Zhang Xiaoqing

Environment Protection Engineering

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2024

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Vol. 50, nr 1

27--41

EN

The adsorption effect of two modified kaolin-chitosan composites prepared by different modification methods (cross-linking method (GL-CS) and click reaction method (TGL-CS) on lead ion wastewater was studied. The structure of TGL-CS has a denser pore structure than that of GL-CS, and the distribution of adsorption sites is more uniform. At 25 °C, pH 4, the adsorbent dosage of 0.05 g/dm3, reaction time of 4 h, and initial mass concentration of 150 mg/dm3, TGL-CS had the best effect on Pb2+ wastewater treatment, and the adsorption capacity was 76.159 mg/g. The adsorption studies of kinetic, thermodynamic, and thermodynamic parameters showed that the adsorption on GL-CS and TGL-CS was best described by the Langmuir model. The adsorption mechanism is mainly chemical adsorption. The adsorption process is spontaneous. These results show that the adsorbent prepared by click reaction has obvious advantages, with more adsorption capacity and adsorption sites, faster adsorption rate, and better application potential.

8

Supplementary Treatment of Wastewater by Using Ecological Lime Derived from Eggshell Waste – A New Sustainable Strategy for Safe Reuse

Assal Aicha, Nasrellah Hamid, Aarfane Abdellatif, Bakasse Mina, El Mahi Mohammed, El Mostapha Lotfi

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 1

180--189

EN

Wastewater from wastewater treatment plants (WWTPs) often requires further treatment before it can be safely reused. Lime is a common and affordable material used for this purpose, but its production can generate significant environmental impacts. This study developed an eco-friendly and effective lime substitute from eggshell waste for wastewater treatment. First, pre-treated wastewater effluent from WWTP El Jadida, Morocco, was collected and characterized. It was found that COD, BOD5, and TSS values showed non-conformity from Moroccan discharge standards, as well as high concentrations of heavy metals such as cadmium (Cd), zinc (Zn), aluminum (Al), chromium (Cr), manganese (Mn), lead (Pb), silver (Ag), beryllium (Be), copper (Cu) and cobalt (Co). These pollutants represent a potential risk to human health and the environmental ecosystem. To reduce this pollution, the optimal mass of lime powder obtained by thermal treatment of eggshell waste was determined by testing a concentration series of 6, 12, 18, 24, 30, and 36 g·L-1. The findings confirmed that the addition of the optimal dose of prepared lime (24 g·L-1) resulted in a significant reduction in pollution parameters, with abatement rates of 77% for BOD5, 63% for COD and 66% for TSS, respectively. Furthermore, the eco-friendly lime substitute also showed promise in reducing the colorization rate for dyes by 84% and removing heavy metals through precipitation. However, the generated by-product loaded with toxic pollutants should be encapsulated in eco-materials to ensure safe operation and contribute to a sustainable management strategy for wastewater treatment.

9

Silica-Magnetite Composite as an Eco-Friendly Adsorbent for Aqueous Tetracycline Removal – Kinetic and Isotherm Studies

Karina Sofyatuddin, Perdana Adli Waliul, Prajaputra Vicky, Isnaini Nadia, Nuufus Putri Hayyatun, Bismi Audia

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 1

82--92

EN

Silica and magnetite have been recognized as emerging and effective environmentally-friendly pollutant removers. In this study, the effectiveness of silica/magnetite (SM) composites derived from local beach sand were developed and evaluated as an environmentally friendly adsorbent for taking up tetracycline from water. The formation of SM composites was verified through characterization performed using Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and Scanning Electron Microscope (SEM) analysis. Two key parameters, kinetics and isotherms, were investigated to find the best condition for tetracycline adsorption using SM composites. In the kinetic adsorption studies, the pseudo-first-order, with correlation coefficients (R2 > 0.99) higher than those of the pseudo-second-order and Elovich models, was performed to be the best-fitting model due to the close alignment between the experimental and theoretical data. The non-linear Langmuir isotherm model offered the most accurate fit (R2 = 0.954, root-mean-square-errors = 1.505) compared to the Freundlich model, signifying that the adsorption process takes place on a uniform surface where the adsorbate is distributed in monolayers. In the present study, the maximum adsorption capacity of tetracycline onto SM composite reached 29.955±4.165 mg/g for 24-hour contact time with an adsorption rate constant of 0.415±0.050 min-1. In conclusion, the developed environmentally conscious composite demonstrates the potential to be an effective adsorbent with remarkable tetracycline removal properties while also providing valuable insights for further research.

10

Laboratory Wastewater Treatment by Using Combination Methods of AOPs and Chemical-Physical Pretreatments

Agustina Tuty Emilia, Arita Susila, Melwita Elda, Bahrin David, Marcelina Revalda, Irdiansyah Hendryal, Karimah Tri

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 1

216--226

EN

Experimental activities carried out in laboratories usually produce complex wastewater. Due to practicum and research activities in educational laboratories, the wastewater generating from these laboratories contains organic and inorganic compounds which are dangerous for the environment if disposed of without prior treatment. Apart from high chemical oxygen demand (COD) and biological oxygen demand (BOD) values, laboratory wastewater also often contains heavy metals such as zinc (Zn), copper (Cu), chromium (Cr), lead (Pb), and iron (Fe) which are included in the hazardous waste category and can pollute the ground water. Therefore, this wastewater must be treated properly. The objective of this study is to reduce the pollutant load contained in laboratory wastewater by using combination methods of advanced oxidation processes (AOPs), and chemical-physical treatment namely coagulation and adsorption processes. The photo-Fenton process was selected as one of AOPs applied in this treatment. The effect of molar ratio variation and irradiation time in the Photo-Fenton process on the pollution load in the form of pH, COD, BOD, TSS, and heavy metals of Zn, Cu, Cr, Pb, and Fe was studied in this research. The results of the analysis of untreated laboratory wastewater samples showed that laboratory wastewater did not meet the wastewater quality standards regulated by the government of Republic of Indonesia. In this study, laboratory wastewater was treated using the pretreatment method of coagulation with alum and adsorption with activated carbon. The best results in this study were obtained in the final adsorption results after treatment with the photo-Fenton method using a molar ratio of 1: 300 for 60 minutes in which several parameters such as pH, Zn, Cu, Pb, and Fe had met environmental quality standards with the value of each parameter of 7; 0.01 mg/L; 2.9 mg/L; 0.03 mg/L; and 3.15 mg/L respectively. Meanwhile, the percentage reduction of COD, BOD, and TSS parameters was 87.49%, 87.02%, and 72.45% respectively.

11

Investigation of the Adsorption Properties of a New Biopolymer Created Using Brown Algae Powder

Merakchi Akila, Belalia Fatiha, Belhouari Nadia

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 1

251--259

EN

The objective of this study was to create a new material utilizing a biopolymer (sodium alginate) and the powder of brown algae for the elimination of organic pollutants like dyes by adsorption from a water-based solution. The alginate/algae composite beads used in this study as an adsorbent were created by inotropic gelation of sodium alginate utilizing calcium ions as a cross-linking agent. The beads thus synthetized had been characterized by using different techniques in order to assess their characteristics. The adsorption procedure was studied in a batch mode at room temperature using methyl violet, a cationic dye chosen as an organic pollutant. The influence of beading parameters like contact time, methyl violet concentration, pH, sorbent amount and agitation speed was studied. It was found that the adsorption capacities were notably influenced by the initial dye concentration, pH and bead dose. Indeed, the results found indicated that the equilibrium sorption of methyl violet by this adsorbent was reached in around 3 hours for the different concentrations studied (10 mg/L, 40 mg/L and 70 mg/L) with percentage dye removal of around 80% at the optimum bead amount of 2 g. The kinetic modeling had shown that the model of the pseudo-second-order kinetic governed the adsorption rate of methyl violet on alginate/brown algae composite beads.

12

Green Almond Peels a Promising Biosorbent for Cationic Dyes Removal: Characterization, Effect of Process Parameters and Kinetic Modeling

Bettayeb Souhila, Merakchi Akila, Lounici Hakim

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 2

351--365

EN

In the present work, almond peels (AP), an inexpensive and widely available cellulosic material in Algeria, have been utilized as an effective natural adsorbent to eliminate methylene blue from water-based solutions. SEM and FTIR analysis were employed to qualify the adsorbent. The effect of particle size, pH of solution, agitating rate and adsorbent dose were optimized to measure the almond peels capacity of adsorption. The pseudo-first and secondorders, Elovich, and intra-particle diffusion models were employed for analyzing adsorption kinetics. Equilibrium adsorption was examined through Langmuir, Freundlich, and Temkin isotherms. The sorption mechanism was most clearly outlined by the pseudo-second-order kinetic and Freundlich isotherm equations. Our experimental findings indicate that the efficacy of employing these porous adsorbents stems not only from their effective performance attributed to their compositional and structural properties but also from their easy separation from solutions owing to their macroscopic dimensions.

13

Cleaning and Management of Water Contaminated with Pesticides through the Process of Adsorption in the Natural Clay of Brari

Behrami Esad, Berbatovci Isak, Xhaxhiu Kledi, Isak Nensi, Andoni Adelaida, Reka Arianit, Hamiti Xhuljeta, Musliu Zehra Hajrulai, Uzunov Risto

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 2

281--291

EN

This study aimed to investigate the potential for widespread application of clay in the purification of water polluted with pesticides and water management through the absorption and desorption of dimethoate and methomyl in the natural clay of Brari (Tirana). While the maximum adsorption of methomyl on Brari clay was reached in 12 hours, the maximum adsorption of dimethoate on Brari clay was reached in 48 hours. To compare the adsorption of methomyl and dimethoate on Brari clay, their water degradation time was also taken into account. Dimethoate dissolves quickly; a contact period of 1–2 hours is sufficient to desorb 81.2% of the material. Dimethoate dissolves in water at 25 °C and has a half-life t1/2 = 30 days. Methomyl is desorbed even faster; in just two hours, 96.2% of the material is desorbed. At 25 °C, dimethoate has a half-life of t1/2 = 14 days and a high solubility of 58 g/L in water. Because methomyl and dimethoate bind poorly to clay, they can contaminate surface and groundwater.

14

Removal of textile dyes from water using cellulose aerogel

Liugė Monika, Paliulis Dainius, Kumpienė Jūratė, Paulauskienė Tatjana

Ecological Chemistry and Engineering. S

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2024

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Vol. 31, nr 1

49--62

EN

In this study, removal of textile dyes from artificially contaminated water was investigated using sorbent synthesised from cardboard waste. Aerogel - lightweight adsorbent - a material with a low density and large surface area. Aerogels obtained from cellulose, chitosan, lignin or pectin have good adsorption properties for removing organic pollutants from wastewater. The aim of this study was to determine the adsorption efficiency of naphthol green B, congo red, methylene blue and rhodamine B from artificially contaminated water using sorbent synthesised from cardboard waste. The mass of the cellulose aerogel (5 mas. %) adsorbents, that were used in the experiments varied from 1.6 g to 2.74 g. The optimal adsorption conditions were determined as pH = 6.0, concentration of dyes - 10 mg L–1 and 18.0 °C -19.0 °C temperature. Under the optimal conditions, the maximum removal efficiency of naphthol green B using aerogel was 16.45 %; congo red - 98.44 %; methylene blue 79.28 %; and rhodamine B - 52.44 %.

15

Skuteczność syntetycznych zeolitów w usuwaniu metali ciężkich i substancji organicznych z roztworów wodnych

Medykowska Magdalena

Wiadomości Chemiczne

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2023

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[Z] 77, 1-2

97--117

EN

With constantly increasing ecological needs, it is necessary to look for suitable solutions aimed at purifying the water and soil environment. Synthetic zeolites, i.e. porous, ion-exchangeable, acid- and heat-resistant, sodium and calcium aluminosilicates, may be the answer to this demand. This paper presents the adsorption capabilities of two synthetic zeolites (Na-X, Na-P1) obtained via hydrothermal reaction of aqueous sodium hydroxide and high-carbon fly ash. For this purpose, the experiment was conducted with adsorbates from two groups: heavy metals (Pb(II), Zn(II)) and organic substances (polymer - poly(acrylic acid) (PAA), nonsteroidal anti-inflammatory drug – diclofenac (DCF)). Adsorption was carried out in single and mixed adsorbate systems (metal-metal; metal-organic substance; organic substance-organic substance). The adsorption capacity of the studied zeolites was determined relative to Pb(II), Zn(II) and DCF. Desorption processes were also carried out to illustrate the regeneration abilities of the examined porous materials. In addition, the structure of the electrical double layer was characterized using potentiometric titrations and electrophoretic mobility measurements. The highest adsorbed amounts of heavy metals in single systems are observed for Na-X, i.e. 322.1 mg/g Pb(II) and 332.5 mg/g of Zn(II). In the case of Na-P1 zeolite, these amounts were 332.9 mg/g and 103.6 mg/g for Pb(II) and Zn(II), respectively. In mixed adsorbate systems there is a decrease in heavy metal adsorption, after the addition of both another metal or organic substance. In the first case, the decrease is small - the adsorption of Pb(II) on Na-X drops to 309.36 mg/g. In contrast, in mixed systems in the presence of anionic organic substances, the decrease in the amount of adsorbed ions is much greater. In the presence of DCF, Pb(II) adsorption on Na-X decrease to 98.7 mg/g, whereas on Na-P1 to 99.7 mg/g. The main mechanisms of the adsorption process in such systems are: competition for the adsorbent's active sites and the formation of complexes between adsorbates of opposite ionic character. However, the addition of a heavy metal causes increase of the drug adsorption. In the case of Pb(II) ions, the amount of DCF adsorbed on Na-X increases from 6.68 mg/g to 12.86 mg/g, and a slight decrease is observed on Na-P1. On the other hand, in the presence of PAA, DCF adsorption on Na-X decreases to 5.86 mg/g. Moreover, the synthesized adsorbents can be successfully regenerated with hydrochloric acid (in the single and mixed systems containing heavy metals). The addition of Pb(II)/Zn(II) and PAA causes a decrease in the zeta potential of the examined zeolites, whereas the addition of DCF increases this parameter. In turn, the surface charge density decreases in the presence of each adsorbate. It was proved that both synthetic zeolites can be successfully used in soil and water purification processes in continuously improved procedures.

16

Porównanie skuteczności wybranych koagulantów w zintegrowanym procesie koagulacji i adsorpcji

Macherzyński Bartłomiej, Wszelaka-Rylik Małgorzata, Olszewska Sylwia

Technologia Wody

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2023

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Nr 2 (80)

53-56

PL

Celem pracy było określenie skuteczności zintegrowanej koagulacji i sorpcji na poprawę podstawowych wskaźników wody takich jak: mętność, barwa i absorbancja UV254nm. W artykule przedstawiono wyniki badań wody podczas procesu koagulacji i zintegrowanego procesu koagulacji i sorpcji. Do analizy wybrano koagulanty wstępnie zhydrolizowane - FLOKOR1ASW, FLOKOR1,2A oraz FLOKOR15 oraz pylisty węgiel aktywny CWZ-22. Próbki wody poddane koagulacji oraz koagulacji i sorpcji pobrano z rzeki Wisty. Koagulanty w zintegrowanym procesie dozowano w optymalnej dawce wynoszącej 3,5 mg Al/dm3, a pylisty węgiel aktywny w dawkach od 20 do 100 mg/dm3. Podczas procesu najwyższe efektywności usunięcia mętności, barwy i absorbancji UV2M wynosiły odpowiednio 99,5 i 93,2 oraz 70,4%.

EN

The aim of the study was was to determine the effectiveness of integrated coagulation and sorption on the improvement of basie water indicators such as: turbidity, color and absorbance UV254nm. The article presents the results of water tests during the coagulation process and the integrated process of coagulation and sorption. Pre-hydrolyzed coagulants - FLOKOR1ASW, FLOKORB1,2A and FLOKOR1S and powder-activated carbon CWZ-22 were selected for the analysis. Water samples subjected to coagulation as well as coagulation and sorption were collected from the Vistula river. Coagulants in the integrated process were dosed in the optimal dose of 3.5 mgAI/dm3, and powder-activated carbon in doses from 20 to 100 mg/dm3. During the process, the highest turbidity, color and absorbance UV2H removal efficiencies were 99.5, 93.2 and 70.4%, respectively.

17

Od odpadów rolniczych do wysokowydajnego sorbentu : węgiel aktywny pochodzący z łupin orzechów laskowych do oczyszczania wody i ścieków

Barczak Beata, Klugmann-Radziemska Ewa, Januszewicz Katarzyna

Przemysł Chemiczny

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2023

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T. 102, nr 9

895--899

PL

Łupiny orzechów laskowych, produkt uboczny przemysłu spożywczego, mają znaczny potencjał jako prekursor do produkcji węgla aktywnego ze względu na ich dużą dostępność i dużą zawartość węgla. Przedstawiono badania możliwości przekształcenia łupin orzechów laskowych w węgiel aktywny, wykorzystany do oczyszczania ścieków z zanieczyszczeń organicznych. Porównano procesy aktywacji fizycznej i chemicznej otrzymanego węgla. Otrzymano wysoce porowaty materiał o powierzchni właściwej 1211 m²/g. Ponadto przedstawiono izotermy adsorpcji i oznaczono pojemność adsorpcyjną biowęgla względem rodaminy B.

EN

Hazelnut shells were pyrolyzed at 500°C for 1 h. The obtained biochar was activated phys. with CO₂ at 800°C or chem. with KOH at 850°C. A porous material with a sp. surface area of 1211 m²/g was obtained. The adsorption properties of activated C were tested in relation to the adsorption of rhodamine B. The adsorption capacity was 64.4 mg/g. The Langmuir, Freundlich, Sips and Toth adsorption equil. models were used to describe the rhodamine adsorption isotherm. The best fit to the exptl. data was observed for the Sips isotherm.

18

Adsorption behaviour of polar solvent and water vapours on Sorbonorit B4 activated carbon

Downarowicz Dorota, Gabruś Elżbieta

Polish Journal of Chemical Technology

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2023

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Vol. 25, nr 4

28--35

EN

In this work, the affinity of the heterogeneous Sorbonorit B4 (SB4) activated carbon toward methyl ethyl ketone (MEK), isopropyl alcohol (IPA), n-propyl alcohol (NPA) and isobutyl alcohol (IBA), and water vapours was examined. Adsorption equilibrium measurements demonstrate a higher adsorption capacity of water vapour than organic compounds at relative pressures above 0.4. The adsorption capacities of SB4 at the same vapor pressure followed the order: NPA> IPA> MEK> IBA. The Langmuir, Dubinin-Radushkevich, Dubinin-Astakhov, and Toth isotherm models were chosen to describe experimental results. Based on the multi-temperature isotherms, the values of the isosteric heat of adsorption were determined for various adsorbate loading. The results indicate a strong influence of VOC molecule structures and the surface heterogeneity of SB4 on the adsorption efficiency. For IPA-SB4 pair, the maximum temperature rise in a fixed-bed bed in the adsorption process and the energy requirement for regeneration were calculated and experimentally verified.

19

Effectiveness of polyethylene glycol-coated silica on ions adsorption in industrial wastewater

Maryudi Maryudi, Rahayu Aster, Hakika Dhias Cahya

Polimery

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2023

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Vol. 68, nr 5

259--263

EN

The effect of coating silica with polyethylene glycol on the adsorption of iron and phosphate ions in industrial wastewater was investigated. Variable factors were temperature and time of coating, PEG concentration, and PEG to silica ratio. Infrared spectroscopy and scanning electron microscopy were used to evaluate the chemical structure and morphology of PEG-coated silica. Optimum iron and phosphate ions removal efficiency was obtained using a coating temperature of 50°C, a coating time of 15 min, a PEG concentration of 20%, and a PEG to silica ratio of 1:3.

PL

Zbadano wpływ powlekania krzemionki glikolem polietylenowym na adsorpcję jonów żelaza i fosforanów ze ścieków przemysłowych. Czynnikami zmiennymi były temperatura i czas powlekania, stężenie PEG oraz stosunek PEG do krzemionki. Do oceny budowy chemicznej i struktury krzemionki powlekanej PEG stosowano spektroskopię w podczerwieni i skaningową mikroskopię elektronową. Optymalną skuteczność usuwania jonów żelaza i fosforanów uzyskano stosując temperaturę powlekania 50°C, czas powlekania 15 minut, stężenie PEG 20% oraz stosunek PEG do krzemionki 1:3.

20

The selective depression effect of sodium hexametaphosphate on the separation of chlorite and specularite

Zhao Fugang, Yu Xiankun, Gao Xiangpeng, Li Mingyang, Chen Xiangxiang

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 2

art. no. 166495

EN

Flotation is the most known beneficiation method for the separation of complex and refractory iron ores. As a typical iron-containing silicates, it is difficult to separate chlorite from specularite, because of the similar surface physicochemical properties. In this study, the selective depression effect of sodium hexametaphosphate (SHMP) was conducted via the cationic micro-flotation. The surface adsorption mechanism between SHMP and the two mineral surface was explored through surface adsorption amount tests, Zeta-potential measurements, Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) analyses. The micro-flotation results indicated that SHMP could selectively depress around 90% of chlorite, while its effect on the floatability of specularite was negligible (<20% depressing). The surface adsorption amount tests, Zeta-potential measurements analysis demonstrated that SHMP selectively adsorb on chlorite surface while on the surface of specularite is feeble. The further surface adsorption analysis via FT-IR and XPS proved that SHMP selective adsorption occurred on the chlorite surface mainly by chemisorption mainly through the chelation reaction between O in the phosphate groups of SHMP molecular and metal ions on surface of chlorite.