Wyniki wyszukiwania - BazTech

1

Zastosowanie mezoporowatej krzemionki SBA-15 oraz krzemionki koloidalnej jako adsorbentów terfenadyny : studium porównawcze

Geszke-Moritz Małgorzata, Moritz Michał

Przemysł Chemiczny

|

2022

|

T. 101, nr 6

404--408

PL

Porównano właściwości adsorpcyjne krzemionki SBA-15 oraz Aerosil wobec terfenadyny jako modelowej substancji leczniczej. Dowiedziono, że krzemionka mezoporowata odznacza się prawie dwukrotnie większą pojemnością adsorpcyjną (160,4 mg/g) wobec leku aniżeli krzemionka koloidalna (85,7 mg/g) przy jednocześnie dwukrotnie mniejszej wartości ilości adsorbatu przypadającej na jednostkę powierzchni adsorbentu. Przeprowadzono matematyczną interpretację procesu adsorpcji, stosując modelowe izotermy: Freundlicha, Langmuira, Jovanovicia, Dubinina i Astachowa oraz Redlicha i Petersona. Wykazano, że dominującą siłą oddziaływania leku z powierzchnią krzemionek jest adsorpcja fizyczna.

EN

Terfenadine was adsorbed from its solns. in MeCN on a SBA-15 and Aerosil SiO2. Nonlinear fitting anal. was used to estimate the parameters of the Freundlich, Langmuir, Jovanovic, Dubinin-Astakhov and Redlich-Peterson isotherms. The max. adsorption capacity was 160.4 mg/g and 85.7 mg/g (Dubinin-Astakhov model) for SBA-15 and Aerosil silicas resp. It was shown that phys. adsorption was the main force of drug-SiO2 surface interactions.

2

Low-cost removal of basic red 9 using cow dung ash

Arya Raj Kumar, Meena Ghanshyam, Thapliyal Devyani, Barman Sanghamitra, Halder Gopinath, Shandilya Pooja

Chemical and Process Engineering

|

2022

|

Vol. 43, nr 2

229-–242

EN

In the present study, basic red 9 had been removed from synthetic waste water using animal waste. Cow dung ash had been prepared and characterized by scanning electron microscope. Morphology analysis shows very fine particles of less than 1 μm. The pH analysis study favours a pH of 8.5 for maximum dye removal. The removal of basic red 9 was very fast on cow dung ash. Percentage dye removal was 80.24% and 95.24 in 5 minutes and 90 minutes, respectively at initial dye concentration of 10 ppm.

3

The Ability of Peat in Adsorption of Biogenic Elements from Water Environment

Matsuska Oksana, Suchorska Olga, Gumnitsky Jaroslaw

Journal of Ecological Engineering

|

2020

|

Vol. 21, nr 4

224--230

EN

The possibilities of using a natural sorbent – peat for the wastewater treatment of ammonium ions and phosphates discharged from runoff into natural reservoirs at high concentrations were investigated. The peat of from the Vereshchytsya-Yanovske deposit of Ukraine of two depths: lowland and upland, was studied. It was established that the lowland samples of peat have higher sorption properties to the investigated pollutants from the aquatic environment than the upland ones. A greater moisture loss in the lowland peat species was observed, as well as the major part of the plant fibers in its structure, which explains its sorption properties. Due to the high content of humic substances, the extraction of cations from the water by peat can occur due to the ion exchange. The adsorption isotherms of both ammonium and phosphate ions on the top and lowland peat species of the Vereshchytsya-Yanovske deposit were constructed and presented. The adsorption isotherm obtained in the experimental studies was used to mathematically establish the isotherm equation, using the Langmuir and Freundlich models to describe the equilibrium of the sorption processes under study. The degree of appropriation of linear equations to the experimental data was evaluated on the basis of the deterministic coefficient, which enabled to determine that in each case the Langmuir equations describe the adsorption isotherms more adequately.

4

Modification of Natural Clays for Use in the Processes of Sewage Treatment

Pimneva Lyudmila A., Zagorskaya Alla A.

Journal of Ecological Engineering

|

2019

|

Vol. 20, nr 8

12--17

EN

The paper deals with the modification of clay sorbents in order to improve the efficiency of of copper ions extraction from wastewater. The study examined the elemental, mineralogical and phase composition of kaolin and montmorillonite clays. The authors analyzed the sorption capacity of natural sorbents under static conditions before and after modification with hydrochloric acid, sodium chloride and sodium hydroxide. The work also determines the change in the physical and chemical properties of the sorbent after modification. The most optimal modification conditions for the purification of wastewater from copper ions are distinguished.

5

The Study of Adsorption Ability of Natural Materials of the Tyumen Region

Pimneva L., Zagorskaya A.

Journal of Ecological Engineering

|

2018

|

Vol. 19, nr 3

225--228

EN

The sorption of divalent copper, natural sorbents of kaolinite and montmorillonite clays and carbon sorbent was studied on model solutions under static conditions. Quantitative characteristics of sorption process of copper ions were obtained. The degree of extraction of copper ions from solution was investigated, depending on the concentration of the initial solution and the weight ratio of the sorbent and volume of treated solution. The magnitude of sorption increases along with the increase in the volume of copper sulfate solution with a concentration of 0.02 M at a constant sample of sorbents. A higher carbon sorption capacity of the sorbent, in relation to ions of copper, was compared to kaolinite and montmorillonite clay. A higher sorption capacity of the carbon sorbent with respect to copper ions is established in the comparison with kaolinite and montmorillonite clay.

6

Anaerobic Sulphate-Reducing Microbial Process Used for Sorbent Preparation

Jencarova J., Luptakova A.

Inżynieria Mineralna

|

2018

|

R. 19, nr 1

73--76

EN

The presence of metals in waters represents today typical anthropogenic pollution. Their increased content, originating in various industry sectors and previous mining activity, is undesired. High concentrations of metals are hazardous for all living organisms. They may accumulate to toxic levels, cause many disorders and diseases and ecological damage under certain environmental conditions. Sulphate-reducing microbial process utilization is one of the options to prepare applicable sorbent which removes metal ions from solutions. This sorbent is created as a consequence of sulphate-reducing bacteria metabolism in anaerobic environment. It is considered to be able to remove many metals from solutions, such as Zn, Cd, Pb, Cu, Ni, As.

PL

Obecność metali w wodach stanowi obecnie typowe zanieczyszczenie antropogeniczne. Ich podwyższona zawartość, pochodząca z różnych sektorów przemysłu i wcześniejszej działalności górniczej są niepożądane. Wysokie stężenia metali są niebezpieczne dla wszystkich żywych organizmów. Zawartość metali przekraczająca poziom toksyczności powoduje wiele zaburzeń i chorób oraz szkód ekologicznych. Wdrożenie procesów mikrobiologicznych jest jedną z opcji przygotowania sorbentu do usuwania jonów metali z roztworów. Sorbent powstaje w wyniku metabolizmu bakterii redukujących siarczany w środowisku beztlenowym. Sorbent taki jest w stanie usunąć z roztworów takie metale jak Zn, Cd, Pb, Cu, Ni, As.

7

Wydzielenie jonów cynku(II) z roztworów siarczanowych i chlorkowych za pomocą żywicy Lewatit MonoPlus SP112

Chrapek M., Gęga J.

Chemistry, Environment, Biotechnology

|

2018

|

Vol. 21

46--51

PL

W prezentowanej pracy przedstawiono wyniki badań wpływu parametrów operacyjnych na szybkość i równowagę wymiany jonów Zn(II) zachodzącej na kwaśnej żywicy Lewatit MonoPlus SP 112. Badania prowadzono z roztworów siarczanowych(VI) i chlorkowych w zakresie stężenia początkowego Zn 2+ od 0,0001 do 0,1 mol/dm3 i pH zmienianego w zakresie od 0 do 6. Stwierdzono, że możliwa jest sorpcja jonów cynku na zastosowanej żywicy, a kinetyka procesu może być opisana za pomocą modelu reakcji pseudo II rzędu. Ponadto zaobserwowano, że ze wzrostem stężenia początkowego Zn2+ wzrasta ilość zaadsorbowanych jonów cynku.

EN

The paper presents the results of research on the influence of operating parameters on kinetics and equilibria of Zn(II) ion exchange on the acidic Lewatit MonoPlus SP 112 resin. The tests were carried out from sulphate(VI) and chloride solutions at the initial Zn2+ concentration ranged from 0.0001 to 0.1 mol/dm3 and pH ranged from 0 to 6. It was found that the sorption of zinc ions on the resin used is possible, and the kinetics of the process can be described by means of a pseudo secondary order equation. In addition, it was observed that the amount of adsorbed zinc ions increased with increasing of Zn2+ initial concentration.

8

Badanie właściwości adsorpcyjnych asfaltenów z wykorzystaniem techniki odwróconej chromatografii gazowej

Plata-Gryl M., Momotko M., Boczkaj G.

Camera Separatoria

|

2018

|

Vol. 10, No. 1

29--36

PL

W pracy przedstawiono wyniki badań nad możliwością wykorzystania asfaltenów w procesach adsorpcji z fazy gazowej. Wykorzystując technikę odwróconej chromatografii gazowej zbadano właściwości powierzchniowe asfaltenów, takie jak wartość składowej dyspersyjnej i specyficznej swobodnej energii powierzchniowej oraz właściwości elektronodonorowe i elektronoakceptorowe powierzchni asfaltenów. Dodatkowo wyznaczono izotermy adsorpcji dla wybranych lotnych związków organicznych. Uzyskane wyniki wykazały, że asfalteny posiadają unikalne właściwości sorpcyjne i mogą być wykorzystane w procesach adsorpcji do oczyszczania gazowych strumieni procesowych. Otrzymane wartości składowej dyspersyjnej swobodnej energii powierzchniowej są porównywalne do wartości uzyskiwanych dla aktywowanego tlenku glinu.

EN

The purpose of this paper was to evaluate the applicability of asphaltenes as sorbent in adsorption processes. To investigate the adsorption properties of asphaltenes, inverse gas chromatography technique was used. It allowed to determine the dispersive and specific components of the surface free energy. Moreover, the electronacceptor and electrondonor properties of the surface were calculated. To explore the potential of the asphaltene adsorbent for removal of volatile organic compounds, adsorption isotherms for selected compounds were determined. Obtained results revealed the high potential of asphaltenes in adsorption processes as they are characterized by unique sorption properties. The value of the dispersive component of the surface free energy indicate that asphaltenes are material with high surface activity, similar to activated alumina.

9

Biosorption of nickel (II) and zinc (II) from aqueous solutions by the biomass of yeast Yarrowia lipolytica

Wierzba S.

Polish Journal of Chemical Technology

|

2017

|

Vol. 19, nr 1

1--10

EN

This study examined the biosorption process of Ni(II) and Zn(II) from an aqueous solution by dead biomass of Yarrowia lipolytica. Optimum biosorption conditions were determined as a function of pH, biomass dosage, contact time, and temperature. The biosorbent was characterized by FTIR, which indicated the participation of hydroxyl, carboxyl, amide and amine groups in the process of binding the metal ions. The results showed that the biosorption processes of both metal ions closely followed pseudo-second order kinetics. The equilibrium data of Ni(II) and Zn(II) ions at 20, 30 and 40°C fitted the Langmuir and Freundlich isotherm models. Langmuir isotherm provided a better fit to the equilibrium data, with a maximum biosorption capacity of the Y. lipolytica biomass for Ni(II) and Zn(II) of 30.12 and 44.44 mg/g respectively. The calculated thermodynamic parameters demonstrated that the biosorption of Ni(II) and Zn(II) ions onto the Y. lipolytica was feasible, spontaneous and endothermic.

10

Modelowanie procesu adsorpcji boldyny na mezoporowatej krzemionce PHTS

Geszke-Moritz M., Moritz M.

Przemysł Chemiczny

|

2016

|

T. 95, nr 7

1365--1368

PL

Przedstawiono zastosowanie mezoporowatej krzemionki PHTS w procesie adsorpcji boldyny. Dokonano matematycznego opisu adsorpcji modelowymi równaniami izoterm Langmuira, Freundlicha, Dubinina i Raduszkiewicza oraz Dubinina i Astachowa. Parametry izoterm oszacowano, wykorzystując dopasowanie nieliniowe oraz metodę regresji liniowej. W przypadku regresji nieliniowej stosowano metodę sumy znormalizowanych błędów jako kryterium optymalizacji wartości parametrów izoterm. Przeprowadzone badania wykazały, że model adsorpcji Langmuira, którego parametry oszacowano metodą regresji nieliniowej, najlepiej opisuje proces adsorpcji alkaloidu na badanym sorbencie.

EN

Boldine was adsorbed from Me2CHOH and MeCN solns. on plugged hexagonal templated SiO2 at 25°C to det. the adsorption isotherms analyzed then by using the Langmuir, Freundlich, Dubinin-Radushkevich and Dubinin-Astakhov models. To det. the isotherm parameters both linear regression and non-linear fitting anal. were used. The equil. adsorption data were best fitted by the Langmuir equation when the non-linear regression was used.

11

Removal of quinoline from aqueous solutions by lignite, coking coal and anthracite. Adsorption isotherms and thermodynamics

Xu H., Huagn G., Li X., Gao L., Wang Y.

Physicochemical Problems of Mineral Processing

|

2016

|

Vol. 52, iss. 1

214--227

EN

Based on the concept of circular economy, a novel method of industrial organic wastewater treatment by using adsorption on coal is introduced. Coal is used to adsorb organic pollutants from coking wastewaters. After adsorption, the coal would be used for its original purpose, its value is not reduced and the pollutant is thus recycled. Through systemic circulation of coking wastewater zero emissions can be achieved. Lignite, coking coal and anthracite were used as adsorbents in batch experiments. The quinoline removal efficiency of coal adsorption was investigated. The coking coal and anthracite exhibited properties well-suited for adsorption onto both adsorbents. The experimental data were fitted to Langmuir and Freundlich isotherms as well as Temkin, Redlich–Peterson (R-P) and Dubinin-Radushkevich (D-R) models. Both Freundlich Isotherm and D-R model provided reasonable models of the adsorption process. The thermodynamic parameters of quinoline adsorption on coking coal were calculated. The thermodynamic parameters indicated that the adsorption process is exothermic and is a physical adsorption. The △S° value indicated that the adsorption entropy decreased because the adsorbate molecule was under restrictions after it adsorption on the coal surface. The coal adsorption method for removing refractory organic pollutants is a great hope for achieving zero emission waste water for a coking plant.

12

Removal of Pb(II) and Cd(II) ions from aqueous solutions with selected organic wastes

Bozecka A., Bozecki P., Sanak-Rydlewska S.

Physicochemical Problems of Mineral Processing

|

2016

|

Vol. 52, iss. 1

380--396

EN

The authors investigated sorption of Pb(II) and Cd(II) ions from aqueous solutions on selected natural wastes: sunflower hulls, walnut shells and plum stones. The chemical and physical structure of the surface of these sorbents was determined using infrared spectrometry and scanning electron microscopy. The most favourable physicochemical parameters of the sorption processes were also defined. The sorption of Pb(II) and Cd(II) ions was described according to the Langmuir and Freundlich models. It has been shown that the adsorbents studied can be effectively used in removing heavy metals from aqueous solutions. The sunflower hulls have the highest sorption capacity for Pb(II) and Cd(II) ions. It is equal to 36.93 mg/g for the Pb(II) ions and 19.93 mg/g Cd(II) ions. The calculated values of thermodynamic functions indicate a spontaneous (ΔGº< 0) and exothermic (ΔHº< 0) nature of the sorption processes. A participation of ion exchange in these processes is significant. Desorption tests confirm that the adsorbed heavy metals can be recovered and the sorbent materials after regeneration can be reused.

13

Kinetics and isotherm modelling of Zn(II) ions adsorption onto mine soils

Jalayeri H., Salarirad M. M., Ziaii M.

Physicochemical Problems of Mineral Processing

|

2016

|

Vol. 52, iss. 2

767--779

EN

The soils consist of various components that can play a significant role in control of heavy metals in the environment. Therefore, understanding of adsorption properties of soil is essential in solving pollution problems around mine sites. The goal of this paper is to study Zn(II) ions adsorption onto copper mine soil. Soils were examined via X-ray diffraction and scanning electron microscopy. The influence of various parameters such as effect of pH, adsorbent dose, and initial concentration of Zn(II) ions on adsorption was evaluated by batch method. The adsorption isotherms of Zn(II) ions such as Langmuir, Freundlich, and Temkin were studied. The Langmuir isotherm indicated an excellent fit for the experimental data in comparison with other isotherms that shown monolayer adsorption onto a homogenous surface. A number of kinetic models were tested to fit the kinetic data. The results show that soils can be more effective in decreasing heavy metals contamination specially Zn(II) ions from solution phase.

14

Removal of reactive blue 29 dye by adsorption on modified chitosan in the presence of hydrogen peroxide

Naghizadeh A., Nabizadeh R.

Environment Protection Engineering

|

2016

|

Vol. 42, nr 1

149--168

EN

Industrial effluents that carry dyestuff into natural water systems are serious environmental concern. Complex aromatic structures of dyes make them more stable and more difficult to remove from the effluents discharged into water bodies. In the present study, removal of reactive blue 29 dye with chitosan and modified chitosan with Cu complexes from aqueous solution was investigated in a batch adsorption system with respect to the changes in the contact time, pH of solution and chitosan dosage. Adsorption isotherms of the dye onto chitosan were also studied. The results revealed that the adsorption capacity of chitosan with Cu complexes is lower than that of chitosan without Cu complexes. Also effect of H2O2 on adsorption when we used chitosan without Cu complexes is more considerable. The results also demonstrated that adsorption capacity of reactive blue 29 dye on chitosan was higher at lower pHs. Finally, the Langmuir isotherm showed the best conformity to the equilibrium data.

15

Badania skuteczności adsorpcji 2,4,6-trichlorofenolu z modelowych roztworów wodnych na wybranych trocinach

Kuśmierek K., Olkowicz K., Świątkowski A.

Ochrona Środowiska

|

2015

|

Vol. 37, nr 4

19--24

PL

Celem pracy była ocena przydatności trocin do usuwania 2,4,6-trichlorofenolu (TCP) z wody. Do badań wybrano cztery biosorbenty pochodzące z drewna dębowego, olchowego, wiśniowego i sosnowego. Zbadano wpływ dawki trocin, pH roztworu oraz siły jonowej na skuteczność usuwania TCP z modelowego roztworu wodnego. Do opisu kinetyki adsorpcji zastosowano równania pseudo I i pseudo II rzędu, wykazując, że kinetyka przebiegała zgodnie z modelem pseudo II rzędu. Izotermy adsorpcji TCP na trocinach w warunkach równowagowych opisano równaniami Freundlicha, Langmuira, Langmuira-Freundlicha oraz Sipsa. Wykazano, że TCP był najskuteczniej usuwany na trocinach dębowych, podczas gdy najgorszym adsorbentem okazały się trociny sosnowe. Uzyskane wyniki pokazały, że trociny mogą być skutecznym i tanim adsorbentem do usuwania chlorofenolu z wody. Można je wykorzystać np. do tworzenia barier ochronnych oraz ekranów ograniczających przenikanie i migrację zanieczyszczeń organicznych do wód powierzchniowych i podziemnych.

EN

The aim of this study was to evaluate the usefulness of sawdust for 2,4,6-trichlorophenol (TCP) removal from water. Four different wood-derived biosorbents, namely oak, alder, cherry and pine sawdust, were selected for experiments. Effect of the sorbent dose, solution pH and ionic strength on efficacy of TCP removal from a model solution was investigated. The adsorption kinetic data were analyzed using the pseudo-first and pseudo-second order models, demonstrating the latter to represent the adsorption kinetics. The isotherms of TCP adsorption on the sawdust were fitted against the Langmuir, Freundlich, Langmuir-Freundlich and Sips equations. It was demonstrated that the oak sawdust removed TCP most efficiently, while the pine sawdust was the worst sorbent. The results revealed that sawdust might be an efficient low cost adsorbent for chlorophenol removal from water. It may be employed e.g. in protective barriers and shields limiting organic contaminant penetration and diffusion into surface and groundwater.

16

Sorpcja fenolu z roztworów wodnych na konwencjonalnych i niekonwencjonalnych sorbentach

Dudziak M., Werle S.

Inżynieria i Ochrona Środowiska

|

2015

|

T. 18, nr 1

67--81

PL

Badania własne przedstawione w niniejszej pracy dotyczą procesu sorpcji fenolu z wody na wysuszonych osadach ściekowych i na stałych produktach ubocznych powstających podczas procesu ich zgazowania (popiół). Zgazowanie jest obiecującą metodą termicznego zagospodarowania palnych substancji organicznych, niemniej jednak wciąż nierozwiązanym problemem jest sposób zagospodarowania powstających stałych produktów odpadowych. W ramach badań statyki procesu określono zarówno zdolność sorpcyjną, jak i czas osiągnięcia stanu równowagi fenolu na badanych materiałach sorpcyjnych. Badano także wpływ początkowego stężenia fenolu na jego pojemność sorpcyjną. Do matematycznego opisu sorpcji wykorzystano równania Langmuira oraz Freundlicha. Zakres pracy obejmował również ocenę zjawiska uwalniania z materiałów adsorpcyjnych pierwotnych substancji nieorganicznych i organicznych wraz z wyznaczeniem efektu toksycznego roztworu, stosując metody pośrednie. W podsumowaniu pracy, bazując na rezultatach wyników badań eksperymentalnych oraz różnych źródłach literaturowych, porównano pojemność sorpcyjną fenolu na konwencjonalnych i niekonwencjonalnych sorbentach.

EN

The use of adsorption methods in wastewater treatment allows achieving high quality levels of the streams discharged into the environment. This is particularly taking into account the presence of different toxic and hazardous organic and inorganic substances in the wastewater. This problem applies to both municipal wastewater after mechanical-biological treatment as well as to industrial wastewater. Active carbon is the most commonly used for this purpose. However, novel opportunities are sought, including, for example, the use of waste (with appropriate physicochemical characteristics) as sorbents. The studies presented in this paper are related to the process of sorption of phenol from water on the dried sewage sludge and solid by-products generated during the gasification process (ash). Gasification is a promising method of thermal management of combustible organic substances. Nevertheless, there is still an unresolved problem connected with management of solid waste by-products generated during the process. In the frame of the study of the process statics susceptibility to sorption and the time to reach steady state of the phenol on sorption materials studied were determined. The effect of the initial concentration of the phenol on his sorption was also examined. For the mathematical description of adsorption Langmuir and Freundlich equations were used. The scope of the work also included an assessment of the phenomenon of release from adsorbent materials the primary inorganic and organic substances. Simultaneously, a solution toxic effect based on the indirect methods was determined. Additionally, based on the literature results, efficiency of the phenol sorption using conventional and non-conventional sorbents was determined. Phenol sorption proceeded to a greater extent on the ash produced during the gasification process than on the dried sludge subjected to heat treatment. The adsorption equilibration depended also on the absorbent material. Moreover, the increase of initial phenol concentration corresponded to the increase of phenol sorption. The goodness of fit of the theoretical adsorption isotherm (according to the Langmuir or Freundlich equations) to experimental data in the tested range of phenol concentrations (from 60 to 90 mg/dm3) depended on the tested sorbent material. In the case of phenol sorption on the ash the determination coefficients for both isotherms were similar, and in the case of the dried sludge better determination coefficient was obtained for the Freundlich isotherm. The analysis of the isotherm coefficients confirmed high sorption of phenol on the ashes as in the previous studies. Phenol sorption capacity on the sorbents tested in this study was greater than for the other unconventional adsorbents (bagasse fly ash, neutralized red mud, olive pomace) only in the case of ash. The tested sorbent materials released primary organic and inorganic substances on the contact with deionized water. The intensity of this phenomenon was greater for the dried sludge than for the ash. The increase of the toxic effect of the solution of this material was also observed. These studies, however, require continuation for better understanding of this phenomenon.

17

Adsorption of copper ions from aqueous solutions on natural zeolite

Zendelska A., Golomeova M., Blazev K., Krstev B., Golomeov B., Krstev A.

Environment Protection Engineering

|

2015

|

Vol. 41, nr 4

17--36

EN

The adsorption of copper ions from synthetic aqueous solutions on natural zeolite (clinoptilolite) was examined. In order to determine the rate of adsorption and the copper uptake at equilibrium, a series of experiments were performed under batch conditions from single ion solutions. Equilibrium data were evaluated based on adsorption (Langmuir and Freundlich) isotherms. The adsorption kinetics is reasonably fast. In the first 20 min of the experiment, approximately 80% of Cu2+ ions is adsorbed from the solutions. Data obtained from the kinetic experiments have been described by the pseudo-second order kinetic model as well as by the Weber–Morris and Furusawa–Smith models.

18

Corrosion and Corrosion Protection of Aluminum in Hydrochloric Acid by Using Piperidine

El-Meleigy A. E., Youssef G. I., El-Shayeb H.A., El-Shamy A. M.

Ochrona przed Korozją

|

2014

|

nr 3

66--71

EN

The corrosion and corrosion inhibition of aluminum in different concentrations of HCl solutions in the absence and presence of piperidine was investigated using weight loss method and thermometric technique which complemented with surface examination using scanning electron microscopy (SEM). It has been found that piperidine acts as a good corrosion inhibitor for aluminum and the action depends on the concentration of both acid and inhibitor. The concentration of 2.25 M HCl was chosen to carry out the tests of additives either separately or in pairs. Results for weight loss and thermometric measurement indicated that inhibition efficiency increases with increasing inhibitor concentration. It was found that adsorption of piperidine on aluminum surface follows Langmuir adsorption isotherm with a spontaneous process. On the other hand, addition of increasing amounts of NaNO3 to 2.25 M HCl showing that, at lower nitrate concentration there are a decrease in the induction period which is accompany by a rise in the maximum temperature Tm. While at higher ones C > 0.1, an increase in the induction period is manifested. The high dissolution rates of metals in acidic NO3 solution are the result of an autocatalytic process involving the partial reduction of the NO3 – ion to NO2 .

PL

Korozję aluminium wystawionego na działanie różnych stężeń roztworu HCl oraz inhibitowanie korozji dzięki obecności piperydyny analizowano, badając utratę masy metalu i stosując metodę termometryczną uzupełnioną o badania powierzchni za pomocą skaningowego mikroskopu elektronowego (SEM). Stwierdzono, że piperydyna działa jako skuteczny inhibitor korozji aluminium, a jej działanie zależy od stężenia kwasu i inhibitora. Dodatki badano osobno lub w parach w roztworze 2,25 M HCl. Wyniki pomiarów termometrycznych i wartości utraty masy wskazują, że skuteczność inhibicji zwiększa się wraz ze wzrostem stężenia inhibitora. Stwierdzono ponadto, że adsorpcja piperydyny na powierzchni aluminium ma charakter spontaniczny i przebiega wzdłuż izotermy adsorpcji Langmuira. Z drugiej strony, dodawanie coraz to większych ilości NaNO3 do roztworu 2,25M HCl wykazało, że przy niższych stężeniach azotanównastępuje zmniejszenie okresu indukcji, któremu towarzyszy wzrost maksymalnej temperatury Tm. Natomiast przy wyższych stężeniach C > 0,1, następuje wzrost okresu indukcji. Szybkie tempo roztwarzania metalu w kwaśnym roztworze NO3 jest wynikiem autokatalitycznego procesu obejmującego częściową redukcję jonów NO3 – do NO2 .

19

Investigation of sorption characteristics of anaerobically digested dewatered municipal sewage sludge

Varank G., Demir A., Bilgili M. S., Top S., Sekman E., Yazici S., Erkan H. S.

Environment Protection Engineering

|

2014

|

Vol. 40, nr 4

119--133

EN

Physical, chemical, morphological properties and sorption characteristics of anaerobically digested dewatered municipal sewage sludge have been investigated including the surface area, pore size distribution, chemical composition, surface chemistry structure, surface physical morphology, mineralogy, cation exchange capacity, heavy metal content, total solid, total volatile solid, total Kjeldahl-N, total phosphorus content of the sewage sludge. The sorption potential of sewage sludge for the removal of 4-CP and 2,4-DCP from aqueous solutions was examined by investigating their adsorption isotherms and kinetics in a lab-scale batch study. Findings of this study clearly showed that sewage sludge provides chlorophenol removal in the landfill body as disposed with solid wastes.

20

Charakterystyka procesu adsorpcji azotetrazolanu w gruntach organicznych na przykładzie torfu

Borkowski A., Rydelek P., Szala M.

Inżynieria Ekologiczna

|

2012

|

Nr 29

17-25

PL

W prezentowanej pracy przedstawiono wyniki badań dotyczących procesu adsorpcji azotetrazolanu w gruntach organicznych. Sole azotetrazolu są przykładem heterocyklicznych związków organicznych, w których zawartość azotu w cząsteczce przekracza 80% masowych. Z tego względu, oraz z uwagi na wysoką stabilność termiczną, azotetrazole i ich sole są obecnie intensywnie badaną grupą związków wysokoenergetycznych o potencjalnie szerokich zastosowaniach zarówno w technice cywilnej jak i wojskowej. Nie mniej istotnym aspektem zainteresowań tymi związkami są zagadnienia związane z procesami migracji i kumulacji w środowisku naturalnym. Wyniki przeprowadzonych oznaczeń wskazują na względnie słabą adsorpcję azotetrazolanu w badanych gruntach organicznych. Maksymalne pokrycie powierzchni adsorbentu (torfu) monomolekularną warstwą azotetrazolanu wg modelu Langmuira wyniosło 0,016 mol kg-1, podczas gdy adsorpcja na węglu aktywnym (Merck) wyniosła 0,23 mol kg-1. Niska wartość maksymalnej ilości azotetrazolanu, jaką mogły zaadsorbować badane grunty może wiązać się z dysocjacją azotetrazolanu amonu w roztworze wodnym, czego efektem jest powstanie anionu azotetrazolanowego. Ujemne naładowanie tego jonu może być jedną z przyczyn utrudnionej adsorpcji tego związku do powierzchni cząstek glebowych.

EN

The paper presents results of studies on the adsorption of azotetrazolate on organic soil. Azotetrazolate salts are examples of heterocyclic organic compounds, in which the nitrogen content in the molecule exceeds 80% by mass. Therefore, and due to the high thermal stability, azotetrazole and their salts are now intensively studied group of compounds with potentially broad applications in both civil engineering and the military, which may potentially be connected with environmental contamination of ground water. The results of presented studies indicate a relatively weak adsorption of azotetrazolate on the investigated organic soils. The low value of the maximum amount of adsorption of azotetrazolate probably is involved with the dissociation of ammonium azotetrazolate in aqueous solution, resulting in the formation of the azotetrazolate anion. The negative charge of this ion may be one reason more difficult adsorption of this compound on the surface of soil particles.