Removal of the dye of acid bright red 4R from water solutions on activated carbons

Dyes are compounds widely applied in the different branches of industry, such as: paint, textile, cosmetic, paper, leather, food and other industries. Presence of dyes in water, even in ultralow concentrations, can negatively influence life of organisms in this environment. There are many methods of dye removal: chemical oxidization, coagulation, membrane processes, ionic exchange and also process of adsorption. It is possible to increase the capacity of sorption considering removed dyes through corresponding physical or chemical modification of adsorbents. The aim of the presented work was determination of dye (Acid Red 18) removal efficiency from water solutions by the method of adsorption with the use of active coals. Initial WG-12 carbon and carbons specially modified with use of CO2, H2O and air were used in the research. Modifications with use of the three first factors were conducted in circulating stove at temperatures of 400 and 800°C, but active carbons were also treated with 20 and 30% hydrogen peroxide solution. The conducted research on the sorption of Acid Red 18 has shown that better effects (greater sorption capacities) were obtained in case of activated carbons modified at temperature of 800°C, slightly worse ones were got at temperature 400°C, and the smallest for initial carbons. Similar results were obtained for carbon modified with H2O2 solutions. It is possible to put carbons modified in this way in following order: WG-12 (H2O2 20%) > WG-12 (H2O2 30%) > WG-12 initial.Barwniki są związkami szeroko stosowanymi w różnych gałęziach przemysłu, takich jak: przemysł farbiarski, tekstylny, kosmetyczny, papierniczy, skórzany, spożywczy itp. Obecność barwników w wodzie, nawet w bardzo niskich stężeniach, może negatywnie wpływać na życie organizmów w tym środowisku. Istnieje wiele metod usuwania barwników - utlenianie chemiczne, koagulacja, procesy membranowe, wymiana jonowa, a także proces adsorpcji. Aby zwiększyć pojemność sorpcyjną węgli aktywnych ze względu na usuwane barwniki, można tego dokonać poprzez odpowiednią modyfikację tych adsorbentów. Celem prezentowanej pracy było określenie efektywności usuwania barwnika (pąs kwasowy 4R) z roztworów wodnych metodą adsorpcji z użyciem węgli aktywnych. W badaniach wykorzystano węgiel wyjściowy WG-12 oraz węgle specjalnie modyfikowane przy użyciu CO2, H2O oraz powietrza. Modyfikacje przy użyciu trzech pierwszych czynników prowadzono w piecu obrotowym w temperaturze 400 i 800°C, natomiast węgle aktywne traktowano także 20 i 30% roztworem nadtlenku wodoru. Przeprowadzone badania sorpcji pąsu kwasowego 4R wykazały, że lepsze efekty (większe pojemności sorpcyjne) uzyskano w przypadku węgli aktywnych modyfikowanych w temperaturze 800oC, nieco mniejsze w temperaturze 400°C, najmniejsze dla węgli wyjściowych. Podobne wyniki otrzymano dla węgli modyfikowanych roztworami H2O2. Węgle modyfikowane w ten sposób można uszeregować następująco: WG-12(20% H2O2) > WG-12(30% H2O2) > WG-12 wyjściowy

Sorption of Chromium Cr(VI) in the Presence of Benzoic Acid on Selected Activated Carbons

Węgle aktywne wykorzystywane są do oczyszczania wody i ścieków m.in. ze związków organicznych. Ze względu na to, że na powierzchni węgli aktywnych znajdują się grupy funkcyjne o różnym charakterze, mogą sorbować także jony m.in. metali ciężkich. W pracy przedstawiono wyniki sorpcji chromu Cr(VI) przy dwóch wartościach pH: wyjściowym, wynoszącym ok. 4,8 oraz 7 z roztworów jednoskładnikowych oraz z roztworu zawierającego także związek organiczny, którym był kwas benzoesowy. Przeanalizowano wpływ jednoczesnej obecności kwasu benzoesowego na wielkość pojemności sorpcyjnej węgli aktywnych WG-12, F-300 i ROW 08 w stosunku do chromu Cr(VI). Przeprowadzone badania wykazały, że w przypadku sorpcji Cr(VI) z roztworów jedno- i dwuskładnikowych przy wyjściowym pH roztworu największe pojemności sorpcyjne uzyskano dla węgla F-300, nieco mniejsze na węglu WG-12, natomiast najmniejsze dla węgla aktywnego ROW 08. W przypadku sorpcji z roztworu o pH = 7 największe pojemności sorpcyjne uzyskano dla węgla ROW 08, następnie dla F-300, najmniejsze dla WG-12.The activated carbons are used for water treatment among others in eliminating organic compounds. Due to the fact that on the surface of activated carbons there are functional groups of different nature they can also absorb ions among others of heavy metals. The results of sorption of chromium Cr(VI) at two pH values were presented: output ratio of about 4.8 and 7 of solutions of mono-and from a solution containing the organic compound, which was benzoic acid. The influence of the simultaneous presence of benzoic acid to the size of the sorption capacity of activated carbons WG-12, F-300 and RD 08 for chromium Cr(VI). The study showed that for sorption of Cr(VI). One of the solutions and the original binary output pH largest sorption capacity was obtained for the carbon F-300, slightly lower for carbon WG-12, and the lowest for the activated carbon ROW 08 In the case of adsorption from solution at pH = 7, the largest adsorption capacities for carbon achieved ROW 08, then the F-300, the smallest were observed for the WG-12

Changes in the properties of activated carbons on the process of modification

Techniczne węgle aktywne WG-12, ROW 08 Supra i F-300 poddano modyfikacji za pomocą pola ultradźwiękowego. Pierwszy z nich to węgiel WG-12 produkowany przez firmę Gryfskand z Hajnówki. ROW 08 Supra to granulowany i uszlachetniony węgiel aktywowany, który można regenerować termicznie. Produkowany jest z torfu przez holenderską firmę Norit metodą parowo-gazową. Charakteryzuje się dużą objętością porów i znacznym rozmiarem ziaren, co sprawia, że jest powszechnie stosowany do uzdatniania wody pitnej w celu polepszania smaku wody oraz usuwania zapachu, ozonu, chloru i mikrozanieczyszczeń (np. rozpuszczonych substancji organicznych czy pestycydów). Węgiel F-300 to węgiel ziarnowy produkowany przez belgijską firmę Chemviron Carbon. Badano węgle aktywne specjalnie modyfikowane za pomocą roztworu KMnO4. Ze względu na redukcyjny charakter powierzchni węglowej Mn7+, pochodzący z roztworu KMnO4, redukuje się do Mn4+, tworząc na jego powierzchni nierozpuszczalny MnO2. Zmodyfikowany w ten sposób węgiel aktywny może być stosowany do usuwania z wody manganu w niepożądanych ilościach. Celem pracy było wykonanie analiz wybranych wskaźników technicznych, takich jak gęstość nasypowa, liczba jodowa, liczba metylenowa i zawartość popiołu zgodnie z PN.Technical activated carbons WG-12, ROW 08 Supra and F-300 were modified using ultrasonic field. The first is carbon WG-12 produced by block bags from Hajnowka. ROW 08 Supra is refined granulated activated carbon, which can be regenerated thermally, is produced of peat by the Dutch company NORIT by steam and gas. Characterized by high pore volume and a large grain size, which makes it widely used for drinking water treatment in order to improve the taste of water and removal of odor, ozone, chlorine and micropollutants (for example, organic solutes or pesticides). Coal F-300 is a carbon particle size distribution produced by the Belgian company Chemviron Carbon. Test specially modified activated carbon with a solution of KMnO4. Due to the reducing nature of the surface of the carbon derived from Mn7+ KMnO4 solution reduces to Mn4+ form on the surface of insoluble MnO2. This modified activated carbon can be used for removing manganese from water in undesirable amounts. The aim of this study was to perform analyzes of selected technical indicators, such as bulk density, iodine value, the number of methylene and ash content in accordance with Polish standards

Modification of Activated Carbons with Ultrasonic Field

Technical activated carbons WG-12, ROW 08 Supra and F-300 have been modified using ultrasonic field. Firstly was examined the activated carbon WG-12 produced by GRYFSKAND of Hajnówka in Poland. ROW 08 Supra is granulated and refined activated carbon, which can be thermally regenerated. It is produced from peat by Dutch company NORIT by the use of steam-gas method. The carbon is characterized by a large volume of pores and large size of the grains, which makes, that is commonly used for drinking water treatment in order to enhance the taste of the water and remove the odor, chlorine, ozone and micropollutants (e.g., dissolved organic substances or pesticides). The carbon F-300 is produced by the Belgian company CHEMVIRON CARBON. Sonication of activated carbons was carried out in an ultrasonic generator UPS 400 S Hielscher's designed for stationary use. The modification of activated carbons by sonication was made as follows: the test coals were filled with distilled water in an amount of 500 cm3 and treated by ultrasonic field for 5, 10, 15 and 20 minutes. Two series of tests were performed with amplitudes equal 50 and 100%. After sonication process, activated carbons were dried at 145°C to obtain of constant weight. Then, an analysis of selected technical indicators such as bulk density, iodine number, the number of the methylene and the ash content according to the PN were made

Ultradźwiękowe wspomaganie sorpcji kwasów humusowych z wody

Procesy usuwania związków organicznych, w tym substancji humusowych (SH), oraz ich intensyfikacja zajmuje ważne miejsce w technologii wody. Prowadzone są badania nad możliwością podniesienia skuteczności usuwania SH w konwencjonalnych procesach jej uzdatniania jak: koagulacja, sorpcja czy utlenianie. Badania te dotyczą m.in. tzw. procesów pogłębionego utleniania (AOP), w których stosowane są kombinacje czynników fizycznych (promieniowanie UV, ultradźwięki) lub chemicznych (reakcja Fentona) z klasycznym procesem. Do usuwania naturalnej materii organicznej lub intensyfikacji tego procesu, mogą być stosowane ultradźwięki (UD) Uważa się, że UD powodują sonochemiczne utlenianie związków humusowych w pęcherzykach kawitacyjnych, jak również fizyczną dekompozycję lub agregację fragmentów SH. Ze względu na niską skuteczność sonochemicznego utleniania związków o strukturach aromatycznych, badano również metody łączące UD z UV czy O3. Celem przedstawionych badań była ocena możliwości zastosowania energii ultradźwiękowej do intensyfikacji procesu sorpcji kwasów humusowych (KH). Ultradźwięki generowano przy użyciu dezintegratora VCX 750 Sonics & Materials (20 kHz, 750 W), stosując czas sonifikacji 1 i 5 minut (UD 1, UD 5) oraz amplitudę drgań 23–114 µm. Proces sorpcji KH z roztworu (20 mg/dm3) prowadzono na granulowanym węglu aktywnym ROW 08 Supra. Próbki poddawane sorpcji lub sono-sorpcji, przesączono a następnie poddawano analizie (RWO, absorbancja UV254, utlenialność). Skuteczność sorpcji KH wyrażona jako RWO wynosiła 18–27% w zależności od długości czasu kontaktu z węglem. Sonifikacja roztworów powodowała wzrost skuteczności procesu sono-sorpcji względem klasycznej sorpcji, który wynosił dla RWO 10% (UD 1, 114 µm). Wydłużenie czasu sonifikacji do 5 minut zwiększało efekt do 12% (UD 5, 114 µm). Uzyskano także nieznaczne obniżenie absorbancji UV, jednak efekty te nie odpowiadały najkorzystniejszym wynikom ultradźwiękowego wspomagania sorpcji wyrażonym RWO. Przyjmując jako najbardziej miarodajny do ilościowego oznaczenia badanych związków wskaźnik RWO, potwierdzono korzystne działanie ultradźwięków przy krótkim czasie ekspozycji (1 min.) i wyższym natężeniu określonym amplitudą drgań w zakresie 57–114 µm. Sonochemiczne utlenianie KH przed procesem sorpcji potwierdzało obniżenie utlenialności roztworu po sono-sorpcji względem procesu sorpcji (W3). Wzrost skuteczności do 17%, dał jednak rezultat mniej korzystny niż sorpcja KH w krótszym czasie kontaktu z węglem (W1)

The Effect of Ultrasonic Field on the Adsorption of Cadmium Ions

Adsorption on activated carbon is one of the methods applied for removal of heavy metals from water and wastewater contaminated with these elements. Ion exchange is a predominating mechanism in the process of sorption of ions. In case of sorption of heavy metals cations various surface aggregates are formed. Other processes, such as reduction and oxidation, and precipitation in the pores of insoluble compounds (e.g. hydroxides, carbonates) also occur. The processes behind the formation of aggregates with various degrees of resistance have a particular effect on the selectivity of ion exchange on activated carbons. The chemical composition of activated carbon surface – in particular, the presence of oxygen groups capable of ion exchange – shows the most significant effect during adsorption of heavy metals ions. Typically, the surface of the activated carbons produced with the steam-gaseous method has functional groups both of acidic and alkaline character that are capable of exchanging cations as well as anions. Carbon materials with no functional groups can also sorb protons. This is possible due to the fact that dislocated electrons π in the solutions act as Lewis base. There are a number of methods currently being investigated that would allow for improving the efficiency of adsorption of heavy metals. In the presented work the effect of ultrasonic field on the adsorption of cadmium from the model solutions was analyzed. Various configurations of ultrasonic field applied in the process of adsorption were investigated. Ultrasounds were generated in the UP 400S disintegrator. In the first phase the activated carbon in the form of granules was modified with the ultrasonic field of acoustic power density of 42,5 W/cm2or 85,0 W/cm2, at the amplitude of 30 and 60 µm, and at the exposure time of 5, 10, 15 and 20 min. Modified activated carbons were used for sorption of cadmium ions from the solutions at the initial concentrations ranging from 2,24 do 11,2 mg/dm3. The adsorption of cadmium on the activated carbon modified with ultrasounds (at the amplitude of 30 µm and 60 µm) and at the shortest exposure time (i.e. 5 min.) was higher than on the initial activated carbon. The most favorable results were obtained for the activated carbon modified with ultrasonic field with the acoustic power density of 42,5 W/cm3 and the exposure time of 10 min. The efficiency of cadmium adsorption for the highest concentration increased from 50% (the initial activated carbon) to 63%. Also, the work included the analysis of the effect of ultrasonic field on the cadmium solution with the activated carbon in the form of granules in the first phase of static adsorption. In this case, no significant differences in the adsorption capacities were observed. Also, the effect of ultrasounds on the solution used for the adsorption of cadmium did not have an impact on the efficiency of adsorption. In the final phase of the investigations the effect of sonification on the adsorption of cadmium on the powdery activated carbon was analyzed. The control sample was mechanically mixed for 5 min, and the remaining samples were subjected to the ultrasonic field at various amplitudes but with the same exposure time. The efficiency of adsorption combined with ultrasounds was significantly higher. The final concentrations during the adsorption without ultrasounds were in the range of 0,291 to 1,778 mg/dm3 whereas for the adsorption combined with ultrasounds these concentrations ranged from 0,13 to 0,748 mg/dm3

Removal of selected organic compounds on modified activated carbons

The presented work attempted to modify activated carbons with ultrasonic field and evaluate the efficiency of sorption of organic compounds on the obtained modified activated carbons. The results showed that the applied procedure had a positive effect on the removal of the investigated substance. In the case of removal of benzoic and phthalic acids, the highest sorption capacities were obtained for activated carbons modified with ultrasonic waves with the amplitude of 100% and the exposure time of 5 min. The removal efficiency for both acids was approximately 80% at the initial pH and 65% at pH = 8.0. Sorption of imidazole on modified activated carbons showed that lower final concentration was obtained for activated carbons modified with ultrasounds at the amplitude of 100%. The time of exposure to ultrasounds did not have a significant effect on reducing final concentrations. The average removal degree was approximately 45%. Sorption of phenol showed that the average degree of removal was approximately 80% for the solution of the initial pH whereas for higher pH the average removal degree was close to 65%

Snow Cover as a Medium for Deposition of Pollution

The paper presents the results of snow contamination collected from roadsides and parks of Czestochowa in these areas which are out of the impact of a transport. The study was conducted within 2009–2011, in which 120 samples were tested in general. In snowmelt and rain waters that are brought to the sewer or land there are the following pollutants such as: suspended solids, hydrocarbons, heavy metals, biogenic compounds, and even bacteriological contamination. The scope of the research included: pH, total suspended solids, COD and heavy metals in waste water coming into the sewer. On the basis of the survey and analysis of the literature data it is possible to admit the high variation in pollutant concentrations in snow cover, mainly related to the place of sampling. It should also be noted that the other factors, such as: the length of snow cover, the outside temperature, the duration of test runs, the direction of the winds, in the case of the particular type of a substance thawing roads, have affected the results of measurements substantially as evidenced by their differentiation to the point for further measurements. The samples of snow from the sides of roads and parking areas have been characterized by a high content of suspended solids falling within the broad range from 165 to 1325 mg/dm3, COD values ranged from 89.0 to 825.0 mg O2/dm3. The pH of the snow stood at the level of 4.75–6.50. The analysis of the results has shown that the vast majority of the samples has been characterized by a natural or light acidity. The pH value was associated with a place and time of sampling. Most of the snow samples, collected from roadsides with heavy traffic and parking spaces, pointed to their acidic or slightly acidic character. The average content of heavy metals: Cd, Pb, Zn, Cu and Ni within the snow was generally low, which could be due to the fact that the tests were performed within metals concentration in water after the filtration of a suspension. It should be pointed out, however, that the snow from these areas that are exposed to the direct impact of transport, contained more metals for several times, compared with the periphery of busy roads or parking lots. On this basis it can be concluded that the main source of pollution of snow cover was, as analyzed, the catchment traffic, much less air pollution from the other sources. Therefore, the concentration of pollutants in snow cover areas directly adjacent to roads and parking spaces, due to the high concentration of pollutions, ought to be monitored. It should be paid attention to the need to standardize the procedures within sampling the snow

The Immobilization of Zinc and Cadmium in the Soil as a Result of the Use of Waste Substrates

The overall goal of the presented work was to evaluate the effects of a fertilizing mixture of sewage sludge, brown coal and brown coal (O+W+P) ash on mobility of Zn and Cd in soil environment and metal uptake by Miscanthus Giganteus. The pot experiment was done in semi-natural conditions from April 2007 to January 2008. The soil that was used in the experiment was taken from surroundings of Huta Częstochowa and village Dyrdy. Both soils were poorly contaminated with zinc and cadmium (II0) but there was a difference in their profiles, pH, granulometric compositions, sorption properties etc. The soil used in experiments was taken from 30 points lying on the diagonal of the study area with a depth of 0 to 20 cm. The pots used in the experiment had a capacity of 11 dm3,filled with soil of its natural moisture content after sieving through a sieve with a mesh diameter of 5 mm. For each soil there were used 6 combinations of fertilization and each of the combination was repeated in four pots. The effect of the prepared formulation was compared with the operation of the same residues (O), the mixture of sludge and mineral fertilizer (NPK+O), a mixture of lignite and mineral fertilizer (NPK+W) and the fertilization with mineral fertilizers (NPK). During periods of no precipitation or low precipitation values, the plants were watered to obtain soil moisture level of 60%. Results of this study indicate that all types of fertilizer improved sorption properties of soils, but in varying degrees. The reason is the increase in total exchangeable cations and a significant increase in the sorption capacity of the soil and the degree of saturation of the sorption complex bases. Depending on the soil type, the application of the investigated fertilizing mixture resulted in the increase in pH by 0,3–0,4, sorption capacity by 3,0 cmol(+)kg-1 and degree of sorption complex saturation with bases by 10–40%. The applied fertilizing mixture had a significant effect on limitation of bioavailable forms of Zn and Cd in soils and the content of metals in plant biomass. The introduction of O+W+P and W + NPK mixtures mostly affected to reduction of soluble forms of Zn and Cd in 1 M HCl and 0.01 M CaCl2 in studied soils. To estimate the degree of immobilization of metals in media immobilization If ratios were calculated. If values confirmed that the fertilizations O+W +P and W+NPK contributed to the immobilization of Zn and Cd in both soils. In soil enriched with O+W +P there was an observed reduction of zinc content in plants by approximately 15.0% compared to plants grown on control soil. The reduction of the cadmium content in plants grown on enriched soil 1 O+W+P was approximately 15.0% and approximately 17.0% in soil 2 in relation to the content of the crops grown on unfertilized soils. This was primarily the result of the enrichment of soil by organic matter and soil pH increase which resulted in limiting the mobility and bioavailability of heavy metals

Adsorption of Lead on ROW 08 Supra Modified Activated Carbon

The presented work is aimed at comparing two types of gaseous modification: conventional with the use of external source of energy (heat) and originally developed method with Joule heat generated during the flow of electrical current through a carbon bed. Conventional modification of ROW 08 Supra activated carbon was conducted in a rotary furnace in the atmosphere of (1) steam and carbon dioxide at temperature of 400 and 800°C and (2) air at the temperature of 400°C. The modification of activated carbon in the electric heating experimental system (referred to as SEOW) occurred in the process of heating of activated carbon during the flow of electric current through the carbon bed up to 400°C, followed by cooling down with the air or carbon dioxide. Both methods for modification of activated carbons allowed for increasing adsorption capacity towards ions Pb(II). The advantage of heating the activated carbon with the electric heating experimental system (SEOW) required far less energy than in case of conventional method (up to many fold). In case of modified carbon ROW 08 Supra, the increased adsorption efficiency was obtained for coals modified at 800°C and the carbon modified at 400°C with the participation of water vapor. As a result of modification of the SEOW carbons for all analyzed activated carbons, the adsorption percentage increased. Among all the modified activated carbon, the highest adsorption capacity has been given to carbon modified to SEOW through heating it to 400°C and air cooling as well. The results are described by the means of Freundlich and Langmuir isotherm. In order to determine the coefficients of Langmuir isotherm, five different rectilinear forms were used. Among the analyzed issues the best fit to the experimental results obtained for the I Langmuir isotherms (the highest values of the coefficients R2). The impact of pH and temperature on the effectiveness within the adsorption solution of Pb (II) was also analyzed. The most effective adsorption of lead from solutions of pH 2, 4, and 6 occurred at the highest pH, but the differences between the adsorption solution at pH 6 and pH 8 has been low. Within the adsorption from solutions having a pH of 2 a very little adsorption of lead was observed. Furthermore the size of adsorption of solutions at 20, 30 and 40°C was analyzed as well. What has been found is that through increasing the temperature the efficiency of the adsorption process within Pb (II) is raised