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1

Badanie adsorpcji jonów miedzi(II) na materiałach grafenowych

Tian Weihua

Przemysł Chemiczny

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2023

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T. 102, nr 6

566--571

PL

Przygotowano gąbkę grafenową (RGO) i magnetyczne cząstki grafenowe (MGO) i materiały te wykorzystano do usuwania jonów Cu²⁺ z ich roztworów wodnych. Porównano wpływ pH, czasu adsorpcji i dawki adsorbentu na efektywność adsorpcji Cu²⁺ na RGO i MGO. Przy pH 5, początkowym stężeniu Cu²⁺ 10 mg/L i stężeniu adsorbentu 0,6 g/L, adsorpcja była najbardziej efektywna. Stopień usuwania Cu²⁺ przez RGO (99,5%) był wyższy niż przez MGO (94,1%), co było spowodowane nakładaniem się warstw grafenu w MGO i wzrostem oporu dyfuzji jonów w późniejszym etapie adsorpcji. Materiały grafenowe poddano recyklingowi. Po 6 cyklach adsorpcji-desorpcji wydajność usuwania Cu²⁺ wynosiła nadal 92%.

EN

Graphene sponge (RGO) and graphene magnetic particles (MGO) were successfully prepd. and used for removal of Cu²⁺ ions from their aq. solns. The effects of pH value, adsorption time and adsorbent dose on the adsorption efficiency of Cu²⁺ on RGO and MGO were compared. At pH 5, the initial Cu²⁺ concn. 10 mg/L, and the adsorbent concn. 0.6 g/L, the adsorption was most efficient. The removal rate of Cu²⁺ by RGO (99.5%) was higher than that of MGO (94.1%), because of overlapping the graphene layers in MGO and an increase in ion diffusion resistance in the later stage. The graphene materials were recycled. After 6 cycles of adsorption, the removal rate was still 92%.

2

The Needles of Aleppo Pine From the Province of Taza-Morocco – A Biomaterial of Great Potential

Mahmoud Rachid, Hjouji Kaoutar, Mehdaoui Imane, Saoudi Hassani El Mokhtar, Ben Abbou Mohamed, Majbar Zineb, Taleb Mustapha, Rais Zakia

Journal of Ecological Engineering

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2023

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Vol. 24, nr 1

41--50

EN

The needles of the Aleppo pine (Pinus halepensis) (PA) are very abundant in the forest of the National Park of Tazekka (Ta-za-Morocco) and are unexploitable. Moreover, they constitute a potential danger because they facilitate the outbreak of wildfires. To solve this problem, we have considered turning these needles into a biomaterial that could be used as raw material for different uses, such as wastewater treatment. The biomaterial of the Aleppo pine is obtained from its needles which are harvested in spring, dried, cut, crushed, and sieved. The powder obtained is analyzed before and after the extraction of essential oil. The physicochemical and spectroscopic analyses show that this biomaterial is porous, hygroscopic, slightly acidic, moderately moist, and not very conducive. Its average density in the anhydrous state is 0.6. It is rich in carbon (79.91%) and oxygen (18.91%) in the form of aromatic compounds and ketone imprints; thus, relating the presence of cellulose, pectin, lignin, and hemicellulose. Its composition in mineral elements (Na, Mg, Ca, K, Cl, S) is deficient. Gas chromatography-mass spectrometry (GC-MS) analysis of the oils extracted from the needle powder relates that it is a complex mixture of bioactive compounds such as mono-terpenoid α and β-pinene hydrocarbons. These results show that our biomaterial can be used as an adsorbent in wastewater treatment and the extracted essential oils can be used in the pharmacological, agro-food field.

3

Pulp and Paper Wastewater Treatment with Bottom Ash Using Jar Test

Pisceselia Dian F., Arita Susila, Agustina Tuty Emilia

Journal of Ecological Engineering

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2023

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Vol. 24, nr 1

188--194

EN

The wastewater generated from pulp and paper production still contains pollutants and contaminants, so appropriate and economical materials are needed to reduce pollutants by using adsorbents from bottom ash. This study examined the characteristics of bottom ash and pulp and paper wastewater, the effect of stirring time, stirring speed, and adsorbent activation temperature on decreasing the environmental parameters of wastewater. The synthesis of bottom ash as an adsorbent was carried out by heating at 100 and 200 °C for 1 hour. The wastewater treatment process with maximum yield occurs at a stirring speed of 100 rpm for 50 min. The use of bottom ash without heating as an adsorbent in the pulp and paper wastewater treatment process has reduced TSS 77.5%, COD 85.72%, chloride 26.9%, TDS 1143 ppm, and EC 2180 s/cm, which have met the environmental quality standards.

4

Magnetosorption Purification of Water from Petroleum Products

Vozniuk Marta, Shabliy Tetyana, Gomelya Mykola, Sirenko Ludmila, Sidorov Dmytro

Journal of Ecological Engineering

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2023

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Vol. 24, nr 11

155--162

EN

In this work, the processes of purification of oily waters using magnetites were investigated: magnetite synthesized according to the classical method and magnetites modified with hydrophobizing agents (sulfonol or alkylimidazolin). It was shown that magnetite modified with alkylimidazolin in doses of 50–200 mg/dm3 provides a high degree of oil removal from waters of various mineralization. The degree of water purification reaches 97.5–99.8%. Sulfonol-modified magnetite shows greater efficiency than conventional magnetite only at high concentrations (200 mg/dm3) and only in fresh water. Three hours is enough to ensure the maximum degree of purification of water-oil solutions. Changing the amount of hydrophobizing agent (alkylimidazolin) during the synthesis of magnetite reduces the effect of pH on the purification of both fresh and mineralized waters.

5

Adsorbent Characterization from Cocoa Shell Pyrolysis (Theobroma cacao L) and its Application in Mercury Ion Reduction

Nursiah Cut, Desvita Hera, Elviani Elviani, Farida Nurlia, Muslim Abrar, Rosnelly Cut Meurah, Mariana Mariana, Suhendrayatna Suhendrayatna

Journal of Ecological Engineering

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2023

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Vol. 24, nr 6

366--375

EN

In this paper, we describe the characterization and application of adsorbent derived from the pyrolysis of cocoa shells, which is a natural source of adsorbent materials. The adsorbent that was used in this experiment is an environmentally friendly adsorbent that was prepared by the pyrolysis of cocoa shells. For 1.5 hours, the pyrolysis process was carried out at temperatures ranging from 300 to 380 °C. The adsorbent was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and analysis with an X-ray diffraction (XRD) analyzer. Water-ash content and iodine absorption capacity were also determined in accordance with SNI 06-3730-1995. At a contact time of 90 minutes, the adsorption capacity of mercury ions was found to be 0.106 mg/gram. In this study, the adsorption of mercury ions with the adsorbent followed pseudo-second-order models with an R2 value of 0.9929.

6

Fixed Bed System Packed with Porous Materials for Removal of Organic Dye from Wastewater

Cho Young-Sang, Sung Sohyeon

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 1

51--56

EN

Fixed beds were adopted for removal of organic dye from water by photocatalytic decomposition or adsorption. To this end, macroporous titania or silica micro-particles were synthesized from emulsions as micro-reactors and packed in the bed. During feeding aqueous methylene blue solution, UV light was irradiated for generation of active radicals for removal of dye by photocatalytic decomposition. Porous silica particles were also used as adsorbents in the bed for continuous adsorption of organic dye. For regeneration of the porous titania or silica particles, rinsing with fresh water was carried out before repeated cycles.

7

From waste to treat waste : exploitation of marble dust as a harmful pollutant to a green adsorbent for dyes and heavy metals from industrial wastewater

Attia H.A., Farghaly Mohamed G., Saleh A.M., Abdel Khalek M.A.

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 6

art. no. 154007

EN

The marble dust as a harmful industrial waste of marble fabrication was evaluated as aneconomical and efficient green adsorbent for Acid Red-1 dye and lead ions. The XRD, XRF, particle size, surface area and zeta-potential measurements were used to characterize the marble dust. The removal efficiency was optimized by studying several parameters such as pH, temperature, contact time, adsorbent dose and initial concentration. The optimum removal was achieved at pH 6, 20°C after 60 min in the presence of 2.5g/L marble dust. The rates of adsorption were found to follow the pseudo-second-order model. The results showed better fitting to Freundlich isotherm. The thermodynamic studies revealed that the adsorption process is spontaneous, exothermic and favorable at low temperature. The free energy (∆G°), enthalpy (∆H°), and entropy (∆S°) changes were calculated to predict the nature of adsorption.The removal efficiency was improved by calcination of the marble at 700°C. Application for textilewastewater showed high removal efficiency up to 99.9%of inorganic and organic pollutants. The product of treatment was used in the concrete and bricks manufactured, so there is nogeneration of second-order pollutants.

8

Chrome(VI) ion biosorption modelling in a fixed bed column on Dioscorea rotundata hull

Villabona-Ortíz Ángel, Tejada-Tovar Candelaria, Ortega-Toro Rodrigo, Peña-Romero Keily, Botello-Urbiñez Ciro

Journal of Water and Land Development

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2022

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no. 53

202--209

EN

This work aimed to evaluate the yam peel in a bed column packaged as a chromium(VI) ion adsorbent in an aqueous solution. Yam peel was used as adsorbent, prior washing, drying, size reduction, and selection. The experimental work consisted in determining the effect of bed depth, particle size, and temperature, keeping inlet flow = 0.75 cm3∙s-1, pH = 2 and initial concentration of 100 mg∙dm-3. The Adsorption Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDS) analysis on yam (Dioscorea rotundata) peel showed a heterogeneous, porous structure, with functional groups characteristic in lignocellulosic materials. It was analysed regarding the influence of temperature, bed height, and adsorbent particle size on the removal efficiency; it was found that the decrease of particle size and the increase of the bed height favour the elimination of the metallic ion, with removal rates between 92.4 and 98.3%. The bed maximum adsorption capacity was 61.75 mg∙g-1, and break time of 360 min. The break curve’s adjustment to the Thomas, Yoon-Nelson, Dose-Response and Adams-Bohart models was evaluated, concluding that the Yoon-Nelson and Dose-Response models best described the behaviour of the break curve with a coefficient of determination (R2) of 0.95 and 0.96, respectively. The results show that the bio-adsorbent studied can be used to eliminate Cr(VI) in a continuous system.

9

Preparation of Environmentally Friendly Adsorbent Using Oil Palm Boiler Ash, Bentonite and Titanium Dioxide Nanocomposite Materials

Bukit Nurdin, Ginting Eva Marlina, Frida Erna, Bukit Bunga Fisikanta

Journal of Ecological Engineering

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2022

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Vol. 23, nr 12

75--82

EN

Using the products derived from agricultural wastes as low-cost adsorbent materials to remove organic or inorganic contaminants would be ideal, as these materials are readily available in many countries. This study aimed to prepare environmentally friendly adsorbents made from nanocomposite OPBA / Bentonite / TiO2. The coprecipitation method was used in preparing OPBA, and CTAB surfactant was added in bentonite preparation. Meanwhile, the manufacture of TiO2 was carried out using the sol-gel method. Characterization was done by XRD, FTIR, SEM, and BET. The adsorbent spectra did not show a significant shift in absorption where the O-H bonds were becoming weaker due to the presence of TiO2 in the interlayer of bentonite. Another possibility is due to the influence of calcination and heating. The O-H groups of H2O are hydroxylated and dehydrated from within between layers. The formation of the composite OPBA/TiO2/Bentonite does not change the crystallinity of TiO2 significantly. This proves that there is no decrease in photocatalyst activity after the addition of OPBA and bentonite. The morphology of the whole sample has a flake-like structure that has pores. The addition of OPBA into Bentonite/TiO2 causes a decrease in the specific surface area of the sample.

10

Characterization of Spent Bleaching Earth as an Adsorbent Material for Dye Removal

Yulikasari Andriyan, Nurhayati Ervin, Utama Widya, Warmadewanthi Idaa

Journal of Ecological Engineering

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2022

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Vol. 23, nr 4

96--104

EN

Initial research has been carried out to determine the potential of SBE as an adsorbent material through chemical and surface area characterization. Several analyses were performed, including oil content, BET, SEM-EDS, XRD, FTIR, and adsorption capacity. The oil content of the SBE samples were 0.05–0.09%, well below the standard (3%) of hazardous material classification according to the Indonesian government regulation. The chemical composition of SBE, measured by EDS, was dominated by Si and Al elements. XRD analysis revealed two 2-theta diffraction peaks indicated the presence of crystalline SiO2 and Al2O3 phases. Additionally, the results of the FTIR test also showed the dominance of Si-O and Al-O-H functional groups. The SBE morphology, as observed in SEM image, exhibited irregular shape and porous surface covered by impurities. These results supported by the BET data which showed SBE surface area of 10.86 m2g-1 and a mesopore volume of 2.49 cm3 (STP)g-1. Batch adsorption study conducted using low and high range concentration of methylene blue produced a maximum adsorption capacity of 7.993 mg/g and 40.485 mg/g, respectively. The adsorption isotherm analysis showed that the adsorption mechanism was in accordance with the Langmuir isotherm model. Considering its chemical characteristic, SBE has met the criteria for adsorbent material. Nevertheless, the small surface area requires SBE to be activated prior to use.

11

Wpływ modyfikacji bentonitu na jego właściwości adsorpcyjne

Kwaśny Justyna, Balcerzak Wojciech, Kryłów Małgorzata, Wassilkowska Anna, Ruggiero-Mikołajczyk Małgorzata

Przemysł Chemiczny

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2020

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T. 99, nr 9

1335--1338

PL

Przeprowadzono kwaśną aktywację bentonitu za pomocą kwasu solnego, uzyskując wzrost powierzchni właściwej BET adsorbentu o 228 p.p. Zmianie uległy również inne parametry powierzchniowe, takie jak średnica i objętość porów, a także powierzchnia i objętość mikroporów. Impregnacja bentonitu nanometrycznym tlenkiem cyrkonu(IV) nie przyniosła zamierzonych efektów i przyczyniła się do pogorszenia właściwości adsorpcyjnych bentonitu. Efektywność adsorpcji określano, przeprowadzając testy adsorpcji siarkowodoru w warunkach beztlenowych. Skuteczność impregnacji bentonitu oceniano na podstawie obrazów powierzchni adsorbentów, wykonanych za pomocą skaningowego mikroskopu elektronowego (SEM).

EN

Com. bentonite was activated with HCl soln. to increase its sp. surface area by 228 percentage points (p.p.). Changes of diam., pore volume, as well as area and volume of micropores were also obsd. The impregnation of bentonite with nanometric ZrO₂ resulted in deterioration of the adsorption capacity of bentonite. The bentonite adsorbents were used for removal of H₂S from biogas under anaerobic conditions. The ZrO₂ modified bentonite was less efficient than the HCl-activated one, where 99% removal H₂S from N₂ stream was achieved.

12

Wpływ zmian temperatury i czasu wygrzewania próbek skał mułowców na rozkład wielkości porów i powierzchnię właściwą BET na podstawie analiz izoterm adsorpcji

Dudek Lidia

Nafta-Gaz

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2019

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R. 75, nr 1

10--16

PL

Celem pracy jest przedstawienie efektów wygrzewania próbek skał ilasto-mułowcowych na ich strukturę porową, a konkretnie powierzchnię właściwą BET. Struktura porowa surowych i częściowo wygrzanych próbek była mierzona metodą adsorpcji azotu w niskiej temperaturze, w tym przypadku w temperaturze wrzenia ciekłego azotu. Otrzymane izotermy adsorpcji i desorpcji tych próbek były podobne i można je było zaklasyfikować jako typ II, według klasyfikacji IUPAC (Sing et al., 1985). Badania adsorpcyjne wykonano na próbkach skał ilastomułowcowych z utworów ordowiku i syluru oraz fliszu karpackiego. Selekcję próbek przeprowadzono na podstawie analizy składu mineralogicznego, opierając się na ilościowej analizie rentgenowskiej (tabela 3). Głównym kryterium wyboru była zawartość węglanu wapnia, ze względu na to, iż przyjmuje się, że węglany nie ulegają żadnym przemianom poniżej 550°C. Okazało się jednak, że przemiany następują już w znacznie niższych temperaturach. Dla każdej próbki wykonano co najmniej 30 pomiarów adsorpcyjnych, w sumie wykonując ich około 120 pomiarów. Otrzymano krzywe kumulacyjne oraz funkcje rozkładu objętości porów wyznaczone za pomocą algorytmu BJH (ang. Barrett-Joyner-Halenda) (Barrett et al., 1951), z gałęzi desorpcji przy użyciu równania statystycznej grubości warstwy Halseya i korekcji Faass (Faass, 1981) oraz wartości powierzchni właściwej BET (Brunauer et al., 1938). Analizując otrzymane wyniki można stwierdzić, że wszystkie próbki przed przystąpieniem do badania – w celu minimalizacji błędów pomiarowych związanych z heterogenicznością – należy przesiać przez sito 0,5 mm. Następnie po wygrzaniu i przedmuchaniu próbki w urządzeniu SmartPrep należy zatkać probówkę korkiem w celu eliminacji ponownego zawilgocenia. Konsekwencją wygrzewania próbki już nawet w temperaturze 65°C jest wzrost wartości Ro o 3%, lecz przy wygrzewaniu w 425°C rośnie ona aż o 500%. Po wykonaniu analizy adsorpcji azotem zauważono, że wszystkie próbki, niezależnie od ich współczynnika wzrostu lub spadku powierzchni właściwej BET z temperaturą, wykazują tendencję do lokalnych minimów w zakresie 130–190°C i 360–425°C oraz lokalnych maksimów 65–105°C i 250–320°C, których to wyjaśnienie powinno być przedmiotem osobnej pracy analizującej szczegółowo zjawiska fizycznochemiczne występujące w podobnym trendzie we wszystkich analizowanych próbkach.

EN

The purpose of this work was to show the effects of heating up of mudstones rock samples, on their pore structure and especially on their specific surface BET. Porous structures of both – raw and partly heated samples – were measured using nitrogen adsorption method at low temperature i.e. boiling temperature of liquid nitrogen. Adsorption and desorption isotherms obtained for these samples were similar and they could be classified as type II according to IUPAC classification (Sing et al. 1985). Adsorption testing was conducted on clay-mudstone rock samples from Ordovician, Silurian and Carpathian Flysch layers. Sample selection was based on mineral content analysis outcome from quantitative X-ray analysis. The main selection criteria was calcium carbonate content, due to the fact that theoretically they do not undergo any transformations below 550°C, it turned out, however, that they might occur at much lower temperatures. At least 30 adsorption measurements were taken for each sample, totaling about 120 adsorption measurements. Cumulative curves were obtained together with pore volume distribution functions using BJH (BarrettJoyner-Halenda) (Barrett et al., 1951) algorithm from the desorption branch using Halsey’s statistical layer thickness equation and Faass (Faass, 1981) correction and also specific surface measurements (BET). Analysis of the obtained results allow us to conclude, that all samples should be put through the 0.5 mm sieve before analysis to minimize the error associated with its heterogenity. Later, after the sample has been preheated and Nitrogen vented in SmartPrep apparatus, it has to be cork sealed to eliminate secondary moisture adsorption. The consequence of preheating of a rock sample even at 65°C is the increase in its Vitrinite Reflectance by 3%, but after preheating it at 425°C, VR increases even by 500%. After adsorption analysis it was concluded that all the samples – regardless of whether their BET, change with temperature was positive or negative – showed local minima in 130–190°C and 360–425°C, and local maxima in 65–105°C and 250–320°C which phenomena should be examined in detail in further research, in order to analyse both physical and chemical processes present in similar trend in all analyzed samples.

13

Refrigeration systems with one adsorption bed

Neska Mirosław

Journal of Machine Construction and Maintenance - Problemy Eksploatacji

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2019

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no. 2

121--129

EN

In the article, solutions of devices, using the process described by the Clapeyron diagram are analysed. The diagram characterizes the individual operation phases of a single adsorption bed. Those types of the device solutions are used, among others, for heat receiving. The basic principles describing thermal energy transfer in the single bed adsorption refrigeration system are presented. Multiple adsorption refrigeration solutions with a single adsorption bed are discussed. The solutions use different pairs, e.g., an adsorbent-adsorbate pair. The presented case study includes devices using the cyclical heat exchange during the adsorption and desorption process which are applied in the following: adsorption ice maker, adsorption air conditioning and energy storage systems, as well as solutions for heat receiving and adsorption air-heating systems. Moreover, advantages and disadvantages of the adsorption systems mentioned above are reported. Our own solution of a system with a single adsorption bed is presented. The author’s system is characterized by the possibility of using adsorption systems for both air conditioning and adsorption ice makers. The directions and tendencies of further development of the adsorption solutions for refrigeration systems are discussed.

PL

W artykule dokonano analizy rozwiązań urządzeń wykorzystujących proces opisany wykresem Clapeyrona, który charakteryzuje poszczególne fazy pracy pojedynczego złoża adsorpcyjnego. Rozwiązania tego typu są wykorzystywane między innymi do odbierania ciepła. Przedstawiono podstawowe zależności charakteryzujące przepływ energii cieplnej w jednozłożowym adsorpcyjnym układzie chłodniczym. Omówiono szereg rozwiązań adsorpcyjnych układów chłodniczych z pojedynczym złożem adsorpcyjnym, wykorzystujących różne pary jako adsorbent-adsorbat. Prezentowane studium przypadku obejmuje rozwiązania, które wykorzystują adsorpcyjny obieg wymiany ciepła w następujących urządzeniach: wytwornicach lodu, układach klimatyzacji i magazynowania energii oraz rozwiązaniach odbierania ciepła i podgrzewania powietrza. Przedyskutowano wady i zalety przytoczonych przykładowych układów adsorpcyjnych. Przedstawiono własne rozwiązanie układu z pojedynczym złożem adsorpcyjnym, które charakteryzuje się możliwością zastosowania zarówno w układach klimatyzacji, jak i w wytwornicach lodu. Omówiono kierunki i tendencje dalszego rozwoju adsorpcyjnych układów chłodniczych.

14

Removal of zinc, cadmium and nickel from mining waste leachate using walnut shells

Ayala Julia, Fernandez Begona

Environment Protection Engineering

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2019

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Vol. 45, nr 2

141--158

EN

The removal of heavy metals from aqueous solutions using walnut shells was investigated. The effects of pH, contact time, initial metal concentration, adsorbent concentration, and co-ions were studied in synthetic solutions. Metal uptake was found to be dependent on the initial pH of the solution; the removal rate increased upon increasing pH, showing the highest affinity at pH 5–7. The amount of metal removed improved with increasing initial concentration. Increasing adsorbent dosage enhanced removal efficiency, but reduced the amount absorbed per unit mass of walnut shells. The presence of co-ions suppressed the uptake of heavy metals, divalent ions having a more negative effect than monovalentions. The adsorption of Zn, Cd and Ni onto walnut shells was found to fit Langmuir and Freundlich isotherms. The results obtained in the tests with mining waste leachate showed the potential use of walnut shells for the removal of heavy metals.

15

Adsorption of malachite green and congo red dyes from water: recent progress and future outlook

Swan Ng Boon, Zaini Muhammad Abbas Ahmad

Ecological Chemistry and Engineering. S

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2019

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Vol. 26, nr 1

119--132

EN

Global concern on dyes-laden effluent has intensified over the years. Dyes are toxic, stable to light, and hardly oxidized and bio-degraded, hence causing severe physiological effects to living organisms. In water, dye hinders the light penetration for photosynthetic activity, consequently oxygen is deficient for respiration by aquatic creatures. Adsorption has been widely recognized as the effective removal strategy to abate dye wastewater. However, the quests to improve the adsorption efficiency are continuously sought through new adsorbents with special characters, while performing the removal process at optimum operating conditions. This short review aims to summarize the recent progress in adsorption studies of two commonly used industrial dyes, namely malachite green and congo red by various adsorbents. From the quoted studies, the oxidized mesoporous carbon yields a higher adsorption capacity of malachite green at 1265 mg/g, while Fe3O4@nSiO2@mSiO2 displays a greater capacity for congo red removal at 1429 mg/g. A superior adsorption relies not only on specific surface area but also the synergistic interactions of pore width and mesoporosity, surface chemistry, and operating conditions. The dyes properties and factors affecting the adsorption are also highlighted and discussed, with recommendations and future outlook.

16

Adsorptive solar refrigerators based on composite adsorbents 'silica gel – sodium sulphate'

Belyanovskaya Elena A., Pustovoy Grigoriy N., Sukhyy Kostyntyn M., Sergiyenko Yana O., Yeromin Oleksandr O., Prokopenko Elena ., Gubinsky Mikhailo V., Kizek Ján, Lukáč Ladislav

Civil and Environmental Engineering Reports

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2019

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Vol. 29, no. 3

200--208

EN

The operation processes of adsorptive solar refrigerators based on composite adsorbents ‘silica gel - sodium sulphate’ were studied. The correlation between the adsorbent composition and the coefficient of the energy performance of the device was stated. As a consequence of the decreasing of adsorbent mass, the coefficient of performance is increased when sodium sulphate content in the composite increased. Effect of the regeneration process parameters on the composite on the coefficient of performance of the adsorptive refrigenerator was stated. The growth of the coefficient of performance is shown to result from decreasing the difference between adsorbent temperature and regeneration temperature from 85 to 55°C. The maximum values of the coefficient of performance of studied solar adsorptive refrigenerator about of 1.14 are stated for composites containing about 20 wt. % silica gel and 80 wt. % sodium sulphate.

17

Isotherm studies of malachite green removal by yarn processing sludge-based activated carbon

Tang Shu Hui, Zaini Muhammad Abbas Ahmad

Chemistry-Didactics-Ecology-Metrology

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2019

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R. 24, NR 1-2

127--134

EN

Adsorption is an effective wastewater treatment technique which has been widely used in various industrial applications. However, the high operation cost involving commercial activated carbon in industrial processes is the main drawback. Sewage sludge is an auspicious precursor of activated carbon owing to its high carbon content, rich functional groups, low cost, high availability and abundance. This research was aimed to establish the feasibility of converting yarn processing sludge into activated carbon by KI + KOH activation and char at 700 °C for 1 h. The effect of preparation strategies on the properties of sludge-based adsorbents (SBA) was reviewed. The applications of SBAs in the removal of dyes and model pollutants were discussed. The results from this study proved that the preparation of yarn processing sludge-based activated carbon via KI + KOH activation is feasible and effective in the adsorption of dye. This paper provides further insight on the preparation methods of sludge-based adsorbents and dye wastewater treatment using these adsorbents.

18

Materiały kompozytowe MOF-grafen

Szczęśniak B., Choma J., Jaroniec M.

Wiadomości Chemiczne

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2017

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[Z] 71, 9-10

671--691

EN

The effective capture of harmful gases and clean energy sources are of great importance for protection of the environment. In this regard, it is possible to take advantage of the MOF-graphene composites to develop new technologies for environmental and energy-related applications. These composites attract a great attention around the world due to their higher adsorption affinity toward CO2, volatile organic compounds (VOCs), H2 and CH4 reported in comparison to the parent MOFs. Integration of MOFs with graphene nanosheets can be a very effective strategy not only to improve their adsorption performance but also to generate new chemical and physical properties that are not present in MOFs alone. In this review we present the progress in the field of gas capture/storage using MOF-graphene composites with special attention on the correlation between composition, structure and adsorption properties.

19

Adsorption kinetics of fluoride on bone char and its regeneration

Hu J., Wu D., Rao R., Liu R., Lai W.

Environment Protection Engineering

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2017

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Vol. 43, nr 3

93--112

EN

The adsorbent of bone char (BC), produced from the pyrolysis of crushed animal bones, was dominated by the mesopores of the Brunauer Emmett Teller (BET) surface area. The optimal condition for defluoridation with BC was a pH level near 5.0. Chloride and nitrate ions could increase fluoride adsorption capacity in contrast with the effect of sulfate and carbonate ions. The interchangeability between fluoride and hydroxyl groups on BC sorbent was proved by the Fourier transform infrared spectroscopy. Langmuir equation had a better correlation coefficient than the Freundlich equation at various temperatures. Thermodynamic parameters such as Delta G degrees, Delta H degrees, Delta S degrees, Ea and S*, have been calculated to describe the nature of fluoride adsorption onto BC. Negative Delta G degrees and Delta H degrees values at various temperatures indicate a spontaneous process, and its exothermic effect, respectively. However, a positive Delta S degrees value represents an increasing process for entropy. The E-a and S* values ranging from 5 to 40 kj.mol-1 and 0 to 1, respectively, demonstrated that the adsorption is dominated by physical process, although the adsorption kinetic process was involved external diffusion, intraparticle diffusion and chemical reaction equilibrium stage. A high concentration of NaOH solution increases efficiency of removing adsorbed F- ions from the BC surface.

20

Mocne w chłodzeniu. Minimalizacja rozmiarów chłodziarek adsorpcyjnych wykorzystywanych do produkcji wody lodowej cz. 2

Krzywański J., Nowak W., Grabowska K., Widuch A., Wesołowska M.

Energetyka Cieplna i Zawodowa

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2017

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Nr 4

30--35

PL

W świetle doniesień literaturowych słabe przewodnictwo cieplne adsorbentu stanowiącego wypełnienie złóż w adsorpcyjnych agregatach chłodniczych odpowiedzialne jest za niskie wartości współczynnika wydajności chłodniczej COP [1]. Ta sama przyczyna jest powodem dużych gabarytów, jakimi cechują się chłodziarki adsorpcyjne o klasycznej budowie złóż adsorbentu.