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1

Removal of Ni(II) ions from aqueous solutions using manganese oxide nanoparticles from buffelgrass, Cenchrus ciliaris L., as green adsorbent. Kinetics and thermodynamic studies

Kiruba Dunston Angeline, Muthukumaran Karpagasundaram, Thamarai Perumal

Environment Protection Engineering

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2022

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Vol. 48, nr 1

135--149

EN

Manganese oxide nanoparticles (MnONPs) synthesized from buffelgrass, Cenchrus ciliaris (L.), an invasive weed posing threats to ecosystems, are used in this study to remove nickel(II) ions from aqueous solutions. As a biosorbent, the synthesized MnONPs were put to the test. MnONPs were studied for their surface morphology and functional properties. A variety of adsorbent dosages and contact times were tested in batch experiments to see how they affected adsorption rates. At pH 6.0 and room temperature, MnONPs had an 87.1% removal efficiency for Ni(II) ions. Pseudo-second order correlations had a higher R2 value (0.988). In the Langmuir plot, a maximum adsorption capacity of 4.78 mg/g was observed. However, the experimental data fitted well with both Langmuir and Freundlich isotherm models (R2 = 0.99). Spontaneous and exothermic was the nature of the adsorption process. To remove heavy metal ions contaminants from aqueous solutions, these results suggested that MnONPs synthesized from buffelgrass extract could be used.

2

Uptake of phosphates from water solutions on metallurgical sludge

Kostura Bruno, Huczala Radim, Klika Zdeněk, Ritz Michal, Bartoňová Lucie, Matýsek Dalibor

Environment Protection Engineering

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2021

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Vol. 47, nr 3

37--51

EN

Steel-making dust slurry (SS) and convertor dust slurry (CS) were tested for uptake of phosphates from aqueous solutions. The adsorption of phosphates on SS and CS corresponded well with both Langmuir and Freundlich adsorption isotherms, which indicated the combination of physical and chemical processes. The maximum adsorbed amount of phosphates on both dust slurry samples was ca. 11 mg P/g. The study evaluates also the effect of acidic leaching on the retention characteristics of both dust slurry samples. From the slurry samples prepared by acidic leaching, the leached convertor dust slurry (CSL) was the only sample capable to retain phosphates. To reveal the retention mechanisms of phosphates, the original and leached dust slurry samples were analyzed by IR and Raman spectroscopy. Co-precipitation of Ca and Fe phosphates, or surface complexation of phosphates were evaluated as the retention mechanisms of CS and CSL while the retention of phosphates by zincite in the case of SS is probably based on their adsorption.

3

Cooper removal and recovery from aqueous solutions by using selected synthetic ion exchange resins (part II)

Bożęcka Agnieszka, Orlof-Naturalna Monika

Inżynieria Mineralna

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2020

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no. 2, vol. 2

15--20

EN

In paper the possibility of Cu2+ ions removing from aqueous solutions on selected synthetic ion exchange resins (Purolite S 910, S 930, S 940, S 950, C 160) was studied. These processes were described by the Langmuir and Freundlich adsorption models. It was found that the process of Cu2+ ions removing on S 910 and S 930 ion exchangers were the best described by linear equation form of Langmuir isotherm. The fit quality of the Freundlich isotherm is the best for S 940, C 160 and S 950 ion exchangers, which is confirmed by the obtained values of correlation coefficients R. The highest value of the maximum sorption capacity (about 69 mg/g) was obtained for C 160 cation exchange resin with sulfonic groups. For others ion exchange resins the monolayer capacity was decreasing in following order S 940 > S 930 > S 950 > S 910. The S 940 and S 930 ion exchangers were characterized by the highest affinity for Cu2+ ions. The amidoxime polyacrylic chelating resin S 910 was the least efficient. The differences in the affinity of the studied resins towards to Cu2+ ions can be explained by their different chemical or physical structure and particles size. In case of the studied ion exchange resins, the 1/n parameter values of the Freundlich isotherm were in range of 0.21–0.32. Therefore, it can be concluded that energy heterogeneity of the studied sorption system and intensity of Cu2+ ion removal on above ion exchangers are moderate. The K parameter value of the Freundlich equation was also highest for ion exchangers S 930 and S 940.

PL

Wykorzystanie modeli izoterm adsorpcji do opisu procesów usuwania jonów Cu2+ z roztworów wodnych na wybranych syntetycz¬nych żywicach jonowymiennych W pracy zbadano możliwość usuwania jonów Cu2+ z roztworów wodnych za pomocą syntetycznych żywic jonowymiennych firmy Purolite. Do badań wytypowano jonity chelatujące S 910, S 930, S 940, S 950 oraz kationit C 160. Badane procesy opisano za pomocą modelu adsorpcji Langmuira i Freundlicha. Stwierdzono, że liniowa forma równania izotermy Langmuira najlepiej opisuje proces usuwania jonów Cu2+ na jonicie S 910 i S 930. Jakość dopasowania izotermy Freundlicha jest najlepsza w przypadku jonitów S 940; C 160 i S 950 o czym świadczą uzyskane war-tości współczynników korelacji R. Największą wartość maksymalnej pojemności sorpcyjnej (ok. 69 mg/g) uzyskano dla kationitu C 160 z grupami sulfonowymi. Pojemność monowarstwy wyznaczona dla pozostałych jonitów chelatujących malała w szeregu S 940 > S 930 > S 950 > S 910. Największym powinowactwem do jonów Cu2+ cechował się jonit S 940 i S 930. Najmniej skuteczna okazała się amidoksymowa poliakrylowa żywica chelatująca S 910. Zaistniałe różnice w powinowactwie badanych żywic względem jonów Cu2+ można tłumaczyć ich odmienną budową chemiczną, strukturą fizyczną oraz wielkością cząstek. W przypadku badanych żywic jonowymiennych, wartości stałej 1/n izotermy Freundlicha znajdowały się w zakresie 0,21–0,32. Moż¬na zatem stwierdzić, że niejednorodność energetyczna badanego układu sorpcyjnego i intensywność procesu usuwania jonów Cu2+ na ww. jonitach jest umiarkowana. Wartość parametru K równania Freundlicha była najwyższa również dla jonitów S 930 i S 940.

4

Ferric hydroxide-based media for removal of toxic arsenic species. Kinetic, equilibrium and thermodynamic studies

Szlachta M., Wójtowicz P.

Environment Protection Engineering

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2018

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Vol. 44, nr 4

117--129

EN

Adsorption studies were conducted to assess the feasibility of ferric hydroxide-based material for treatment of highly arsenic-contaminated effluents. The experiments were performed in a batch adsorption regime using a synthetic aqueous solution. The contact time between arsenic ions and the adsorbent, initial concentration of arsenic in treated solution, temperature of solution and adsorbent dose had a significant effect on the adsorption performance in the system. Both the mechanism of the process involved and the rate of As(III) and As(V) adsorption were analyzed based on pseudo-firstand pseudo-second order kinetic models. The adsorption data at constant temperature were described by the Langmuir and Freundlich isotherm equation, and the theoretical adsorption capacity of ferric hydroxide was determined to be 43.75 mg/g and 44.04 mg/g for arsenic(III) and (V), respectively. The estimated thermodynamic parameters, including changes in free energy, enthalpy and entropy, revealed that the adsorption is spontaneous and endothermic under applied experimental conditions.

5

Sorption process of Acid Yellow 36 on sludge-based activated carbon

Pieczykolan B., Płonka I.

Proceedings of ECOpole

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2016

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Vol. 10, No. 1

67--73

EN

The study of sorption of dye Acid Yellow 36 on SAC (sludge-based activated carbon) was conducted. For this purpose, anaerobically digested and dewatered sewage sludge was dried at 105ºC to constant weight. Next this sludge was milled to a particle with a diameter of 0.5-1.0 mm and subjected to chemical activation by hydrogen peroxide. After oxidation process the sludge was subjected to thermal transformation in a muffle furnace at 600ºC. In this way obtained a powder activated carbon based on activated sludge (so-called SAC). Based on the results of the study the most favorable parameters of sorption process was achieved as follows: pH value equaled to 2.5 and reaction time equaled to 30 minutes. The linearized forms of Freundlich and Langmuir isotherms showed that the highest value of correlation factor was obtained in the case of Langmuir model. However, in this case, the negative value of constant isotherm was achieved. Therefore, it can be assumed that more accurately in this case is the Freundlich model or other model which was not examined during that studies.

PL

Przeprowadzono badania sorpcji barwnika Acid Yellow 36 z użyciem węgla aktywnego bazującego na osadzie ściekowym. W tym celu ustabilizowany beztlenowo i odwodniony osad czynny wysuszono w 105ºC do stałej masy. Następnie osad ten zmielono do ziaren o średnicy 0,5-1,0 mm i poddano chemicznej aktywacji za pomocą nadtlenku wodoru. Po tym procesie osad spalono w piecu muflowym w 600ºC, uzyskując w ten sposób pylisty węgiel aktywny bazujący na osadzie czynnym (tzw. SAC - czyli „sludge-based activated carbon”). Dla tak spreparowanego węgla aktywnego przeprowadzono badania procesu sorpcji statycznej względem barwnika Acid Yellow 36. Na podstawie przeprowadzonych eksperymentów stwierdzono, że najkorzystniejsza wartość pH wynosi 2,5, a czas kontaktu jest równy 30 minut. Natomiast bazując na graficznych formach zlinearyzowanych modelów sorpcji według Langmuira i Freundlicha, stwierdzono, że największą wartość współczynnika korelacji odnotowano w przypadku zlinearyzowanej formy równania Langmuira. Jednakże w tym przypadku uzyskano ujemne wartości stałych izotermy, dlatego można przypuszczać, że jednak bardziej prawidłowy jest model Freundlicha lub inny rodzaj izotermy, który nie był analizowany w toku tych badań.

6

Removal of methylene blue from aqueous solutions with natural olive pomace modified with ultrasounds and acid

Kalipci E.

Environment Protection Engineering

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2016

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Vol. 42, nr 3

5--17

EN

Removal of methylene blue (MB) from aqueous solution by raw olive pomace (ROP) which is a waste of industrial olive oil and olive pomace modified with ultrasounds and acid (MOP) has been investigated. It was found that the data for ROP and MOP were well fit to the Freundlich isotherm model (R2 equal to 0.864 and 0.834, respectively). As a result; it was determined that raw olive pomace can be used for the removal of methylene blue dye (KF = 10.08 mg/g(dm3/mg)1/n) and modified olive pomace had high adsorption capacity for MB (KF = 73.08 mg/g(dm3/mg)1/n).

7

Assessment of the sorption properties of materials proposed for the construction of insulation barriers

Sobik-Szołtysek J., Bień J., Grosser A.

Environment Protection Engineering

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2016

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Vol. 42, nr 1

169--189

EN

Sorption properties of fine-grain mixtures of mineral waste proposed for construction of separation screens in landfill sites have been examined. The removal of heavy metals by the mixtures analysed was evaluated by the static batch method. It was found that they characterize by high ability to remove heavy metals at the level of over 99%, even with high contents of these elements. The sorption parameters have been determined based on the Langmuir and Freundlich isotherms. The alkaline character of some components of mixtures provides stabilization of pH, preventing removal of heavy metals to the environment in response to contact a barrier with acid solutions.

8

Utilization of agricultural and industrial wastes for metal removal from aqueous solutions

Biegańska M., Cierpiszewski R.

Polish Journal of Chemical Technology

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2011

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Vol. 13, nr 1

20-22

EN

In this study a possibility of obtaining sorbents from basketry wastes has been investigated. Therefore, adsorption of cadmium ions on wicker bark of Salix americana has been studied. The obtained experimental results were described by the Freundlich equation and adsorption kinetics by the pseudo-second order equation. The effect of pH on cadmium ions adsorption by S. americana was also investigated. It has been found that for the pH values ranging from 2 to 7 cadmium removal from the solution was held at almost constant level.

9

Zależność sorpcji pestycydów fenoksyoctowych na węglu AG-5 od ich własności fizyczno-chemicznych

Ignatowicz-Owsieniuk K.

Zeszyty Naukowe Politechniki Białostockiej. Inżynieria Środowiska

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2001

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Z. 14

45-54

PL

W opracowaniu przedstawiono wyniki badań dotyczących usuwania herbicydów fenoksyoctowych z wody na węglu AG-5 metodą sorpcji. Doświadczenia miały na celu ustalenie stopnia eliminowania związku w zależności od budowy tego związku i jego własności fizyczno-chemicznych. Wyniki przedstawiono za pomocą izoterm i równań adsorpcji Freundlicha. Stężenie równowagowe pestycydu oznaczano metodami chromatograficznymi - TLC i HPLC.

EN

The purpose of the project was to assess the efficiency of removal of phenoxyacetic pesticides from water by means of activated carbon sorption. The sorbents AG-5 used in this research were domestic products. It was produced by GRYFSKAND, Ltd., Hajnowka. The static research was conducted according to the Chemviron Carbon methodology. Its aim was to determine the Freundlich isotherm and sorption capacity. The residual concentration of the contaminant in the filtrate was determined by the relevant analytical techniques. Also the concentration of phenoxyacetic acid was identified by TLC and HPLC methods.