Adsorpcija diklofenaka na aktivnim ugljenima

The presence of pharmaceuticals in natural waters has been the subject of numerous studies in the last decade due to their potential negative effects on human health and the environment. Indeed, the intensive use of pharmaceuticals leads to their presence in municipal wastewater. Unfortunately, international and national regulations still do not require continuous monitoring of the presence of pharmaceuticals in natural waters and drinking water, so wastewater treatment plants do not focus on removing them from wastewater. Diclofenac, 2-[2-(2,6-dichloroanilino)phenyl]acetic acid (DCF), is a nonsteroidal compound used as an analgesic, anti-inflammatory, and antipyretic drug and is therefore commonly found in wastewater. Due to its properties, DCF remains biologically active in the aquatic environment and easily enters the food chain. Therefore, DCF should be removed from wastewater before it is discharged into water bodies. Adsorption is an efficient and simple method that can be used to remove DCF from water. In this study, the possibility of removing DCF by adsorption on activated carbon is investigated. Modified hazelnut shell (MHS), modified commercial activated carbon Cullar (MC) and unmodified commercial activated carbon Cullar (C) were batch tested as adsorbents. The tested adsorbents were characterised by FTIR, zeta potential and pHpzc, while the adsorbent efficiency was tested in the pH range from 2 to 10 and described by isothermal studies. Among the tested adsorbents, the maximum uptake of 48.7 mg g–1 was found when modified activated carbon Cullar was used, while both Freundlich and Langmuir isotherm models fitted well to the data. Modified activated carbon from hazelnut shells showed effective removal of DCF.Prisutnost farmaceutskih spojeva u prirodnim vodama tema je brojnih znanstvenih istraživanja tijekom prošlog stoljeća zbog njihova potencijalnog negativnog utjecaja na zdravlje ljudi i okoliš. Naime, česta i prekomjerna uporaba lijekova uzrokuje njihovu čestu pojavu u komunalnim otpadnim vodama. Nažalost, međunarodne i nacionalne regulative ne nalažu kontinuirano praćenje prisutnosti lijekova u prirodnoj i pitkoj vodi, pa stoga ni procesi pročišćavanja otpadnih voda nisu usmjereni na njihovo uklanjanje iz otpadnih voda. Diklofenak (DCF), 2-[2-(2,6-dikloroanilino)fenil]octena kiselina nesteroidni je spoj koji se upotrebljava kao analagetik, protuupalni i antipiretski lijek te se često može naći u otpadnim vodama. Zbog svojih karakteristika DCF ostaje biološki aktivan u vodenom okolišu i lako ulazi u hranidbeni lanac. Stoga je DCF nužno ukloniti iz otpadnih voda prije njihova ispuštanja u vodna tijela. Adsorpcija je učinkovita i jednostavna metoda kojom se DCF može učinkovito ukloniti iz vode. Cilj ovog istraživanja je ispitati mogućnost uklanjanja DCF-a adsorpcijom na modificirane ljuske lješnjaka, modificirani i izvorni oblik komercijalnog aktivnog ugljena Cullar (Cadriano, Italija). Svojstva adsorbensa ispitana su FTIR spektroskopijom, analizom zeta-potencijala i pHpzc. Učinkovitost adsorbensa ispitana je u području pH vrijednosti od 2 do 10 te opisana izotermnim modelima. Među ispitanim adsorbensima, najveća količina DCF-a od 48,7 mg g–1 adsorbirana je na modificirani aktivni ugljen Cullar, dok su dobiveni rezultati dobro opisani i Freundlichovom i Langmuirovom izotermom. Značajne količine DCF-a adsorbirane su i na modificirani aktivni ugljen iz ljuski lješnjaka

Valorisation of Waste Wood Biomass as Biosorbent for the Removal of Synthetic Dye Methylene Blue from Aqueous Solutions

Background and Purpose: Wood and wood processing industries are generators of a substantial amount of waste wood biomass, such as wood chips, shavings and sawdust. Such waste is often unused and its disposal can be a serious environmental problem. Different lignocellulosic waste materials have been successfully used as low-cost adsorbents (biosorbents) for the removal of synthetic dyes, as well as other contaminants, from wastewater. The aim of this study was to valorise the waste wood biomass of ten tree species, out of which seven are the most represented species of the Croatian growing stock, as biosorbents for the removal of synthetic dye methylene blue (MB) from model solutions. Materials and Methods: The waste wood biomasses (shavings or sawdust) of ten tree species, namely common beech, pedunculate oak, sessile oak, common hornbeam, narrow-leafed ash, poplar, European silver fir, Norway spruce, European larch and Douglas fir, were dried and milled prior to characterisation and adsorption experiments. Characterisation of the biosorbents was performed by chemical analysis and Fourier transform Fourier transform infrared spectroscopy (FTIR). Upon characterisation, batch adsorption experiments were conducted in order to survey waste wood biomass as potential adsorbents for the removal of synthetic dye MB. The colour removal was monitored spectrophotometrically at predetermined time intervals. Further adsorption experiments were performed using poplar sawdust. The effects of contact time, biosorbent concentration, initial dye concentration, and pH on the adsorption process were investigated. The experimental data obtained by batch adsorption experiments were analysed using adsorption isotherm models (Freundlich and Langmuir). Results: All the tested biosorbents were found to be very effective for the removal of MB from model dye solution, achieving high removal percentages ranging from 93.25 to 98.50%. Poplar sawdust proved to be the most effective. It was shown that MB adsorption process onto poplar sawdust could be interpreted in terms of Langmuir and Freundlich adsorption isotherm models. Conclusions: Taken together, these results suggest that waste wood biomass has the potential to be used as a low-cost biosorbent for MB removal from aqueous solutions

Alkylammonium clay based nanocomposites vs. alkylammonium- modified lignocellulosic materials in adsorption of Congo Red

In this study, lignocellulose waste materials and smectite clay were modified into adsorbents with surface free ammonium groups. Poplar waste biomass and brewer’s spent grain were chemically modified. Smectite based adsorbents were obtained by intercalation of biopolymer chitosan and hexadecyl trimethylammonium (HDTMA+) cations in smectite structure. The samples were characterized by using X-ray diffraction, elemental analysis and FTIR spectroscopy. The adsorbents were tested for removal of azo dye Congo Red (CR). The concentration of CR was analyzed before and after adsorption test using Thermo Electron Nicolet Evolution 500 UV-VIS spectrophotometer in wavelength range from 250 – 800 nm. It was estimated that adsorption isotherms of CR for all investigated adsorbents showed best fit with Langmuir adsorption model

Validacija sprske verzije upitnika za procenu hronične opstruktivne bolesti pluća

Uvod/Cilj. Upitnik za procenu hronične opstruktivne bolesti pluća (HOBP) (engl. COPD Assessment Test - CAT) je jednostavan i pouzdan test namenjen za merenje ukupnog zdravstvenog stanja bolesnika sa HOBP i koristan je za upotrebu u svakodnevnoj kliničkoj praksi. Cilj ovog istraživanja bio je da se proceni validnost i opravdanost primene srpske verzije CAT. Metode. U studiji je učestvovalo 140 bolesnika u stabilnom stanju HOBP, ispitivanih u ambulantnim uslovima na Klinici za pulmologiju, Kliničkog centra Srbije u Beogradu i Institutu za plućne bolesti Vojvodine u Sremskoj Kamenici. Tokom prvog pregleda bolesnicima je učinjeno ispitivanje plućne funkcije (spirometrija), popunili su CAT upitnik i mMMR (modified Medical Research Council) skalu za procenu stepena dispneje. Pouzdanost CAT test-retesta je ispitivana kod 20 bolesnika od strane istog istraživača. Rezultati. Pokazali smo da srpska verzija CAT ima visoku internu konzistentnost sa Cronbach-ovim alfa 0.88. Test-retest analiza pokazala je dobru korelaciju između CAT rezultata u dve vremenske tačke (Spearmanov r = 0,681; p < 0,01). CAT je umereno korelirao sa mMRC skalom (r = + 0,57), blago sa forsiranim ekspiratornim volumenom u prvoj sekundi (FEV1), (r -0,214), uz pozitivnu korelaciju sa ukupnim brojem pogoršanja HOBP, ali bez jasne regularnosti sa promenom GOLD (Global Initiative for Chronic Obstructive Lung Disease) stadijuma. Zaključak. Srpska verzija CAT je pokazala visoku internu konzistentnost i test-retest pouzdanost. Ona predstavlja pouzdano, jednostavno i lako sredstvo za upotrebu koje se može koristiti u svakodnevnoj kliničkoj praksi za procenu zdravstvenog stanja kod bolesnika sa HOBP u Srbiji.Background/Aim. The Chronic obstructive pulmonary disease (COPD) Assessment Test (CAT) is a simple and reliable tool designed to measure overall COPD related health status and complement physician assessment in rou-tine clinical practice. Objective of this study was to evaluate the validity of the Serbian version of CAT. Methods. Study included 140 outpatients in the stable COPD, recruited from two centres: Clinic for Pulmonology, Clinical Center of Serbia, Belgrade, and Institute for Pulmonary Diseases of Vojvodina, Sremska Kamenica. All patients completed pulmonary function testing – spirometry, the CAT and the modified Medical Research Council (mMRC) dyspnea scale at baseline visit. The CAT test-retest reliability was tested in 20 patients by the same investigator (physician). Results.We demonstrated that Serbian version of CAT had high internal consistency with Cronbach’s alpha 0.88. Test-retest analysis showed good correlation between CAT scores in two time points (Spearman’s ρ = 0.681, p < 0.01). In our study the CAT correlated moderately to mMRC scale (ρ = +0.57), weakly to FEV1 (ρ -0.214), was positively related to number of exacerbations, but did not showed exact regularity with change in the Global Initiative for Chronic Obstructive lung disease (GOLD) stage. Conclusion.The Serbian version of CAT is a reliable, simple and easy-to-use tool that can be used in everyday clinical practice to assess the health status of COPD patients in Serbia

Modified Lignocellulosic Waste for the Amelioration of Water Quality: Adsorptive Removal of Congo Red and Nitrate Using Modified Poplar Sawdust

Since the synthetic dye Congo red and nitrate are notorious contributors to water pollution due to their persistent and potentially toxic nature, it is necessary to develop new efficient methods to remove them from water bodies. Native lignocellulosic materials as biosorbents are mostly inferior, i.e., the adsorption capacities of native materials are lower. Therefore, attempts have been made to improve the adsorption capacities of such materials by physical and/or chemical methods, including the production of biochar. In this study, adsorptive removal was investigated using a novel biosorbent (mPWS) obtained by modifying poplar (waste) sawdust through quaternisation. The characterisation of mPWS included SEM/EDX, FTIR, and MIP analysis. The adsorption of CR and nitrate onto mPWS was studied in a batch system, as a function of contact time (1–240 min), biosorbent concentration (1–8 g/dm3), and initial adsorbate concentration (25–200 mg/dm3). In all experiments, a high removal of both adsorbates, from 60 to over 90%, was achieved. Langmuir and Freundlich adsorption isotherm models were used in order to describe equilibrium adsorption data, while pseudo-first-order and pseudo-second-order kinetic models, and the intraparticle diffusion model, were used to describe possible adsorption mechanisms. The Langmuir model fit the adsorption data of CR well, while the nitrate adsorption process was better interpreted with the Freundlich isotherm model. The kinetics data for both CR and nitrate agreed with the pseudo-second-order kinetics model, while analysis using the intraparticle diffusion model indicated two rate-limiting steps during the adsorption process. Based on the results, it can be concluded that the tested novel biosorbent can be effectively used for the removal of CR and nitrate from water (with its adsorption capacities being 70.3 mg/g and 43.6 mg/g, respectively)

Association among resistin, adenylate cyclase-associated protein 1 and high-density lipoprotein cholesterol in patients with colorectal cancer: a multi-marker approach, as a hallmark of innovative predictive, preventive, and personalized medicine

Background: Elevated concentrations of resistin have been reported in colorectal cancer (CRC), but its interactions with adenylate cyclase-associated protein 1 (CAP-1) are largely unexplored. We investigated resistin plasma concentration, peripheral blood mononuclear cells (PBMCs) resistin messenger ribonucleic acid (mRNA), and CAP-1 mRNA levels in CRC patients, as well as the impact of resistin gene polymorphism rs1862513 on the examined markers. We also explored associations of resistin with high-density lipoprotein cholesterol (HDL-C) and predictive potential of our parameters for CRC. Methods: Eighty-six patients with CRC and 75 healthy adults were included. Commercial ELISA kit was used for obtaining resistin’s concentrations, while polymerase chain reaction (PCR) method was applied for evaluation of resistin and CAP-1 mRNA levels and rs1862513 polymorphism. Results: Plasma resistin and CAP-1 mRNA levels were higher in CRC patients (p < 0.001 and p < 0.05, respectively), while resistin mRNA levels were lower (p < 0.001). Negative association existed among plasma resistin and HDL-C concentrations (ρ = − 0.280; p < 0.05). A model including age, body-mass index, HDL-C, low-density lipoprotein cholesterol (LDL-C), and plasma resistin concentrations as independent predictors of CRC showed very good diagnostic accuracy (AUC = 0.898). We found no associations of rs1862513 with the examined markers. Conclusions: Our study demonstrated increased plasma resistin and CAP-1 mRNA levels, implying their possible interaction in CRC. The association among plasma resistin and HDL-C might indicate that HDL-C is involved in alterations of resistin’s secretion process. As a hallmark of personalized medicine, multi-marker approach in determination of resistin-related parameters might be useful for prediction and prevention of CRC development

Modified Hazelnut Shells as a Novel Adsorbent for the Removal of Nitrate from Wastewater

The aim of the study was to prepare a novel adsorbent by chemical modification of hazelnut shells and evaluate its potential for the nitrate removal from model solutions and real wastewater. The characterization of the novel adsorbent, i.e., modified hazelnut shell (MHS) was performed. The adsorbent characterization included the analysis of elemental composition and the surface characteristics analysis by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The adsorption experiments (batch technique) were performed to investigate the effects of adsorbent concentration, contact time, initial nitrate concentration, and solution pH. The nitrate removal efficiency increased with the increase in MHS concentration and decreased with the initial nitrate concentration. MHS was found to be effective in nitrate removal over a wide pH range (from 2 to 10), and the highest amount of nitrate adsorbed was 25.79 mg g&minus;1 in a model nitrate solution. Depending on the aqueous medium (model solutions or real wastewater samples), it was shown that both Langmuir and Freundlich adsorption isotherm models can be used to interpret the adsorption process. It was found that the kinetics are well described by a pseudo-second order model and the nitrate adsorption process can be controlled by chemisorption. The intraparticle diffusion model has been used to identify an adsorption-controlled process by diffusion mechanisms. Adsorption/desorption experiments in column confirmed that MHS could be successfully used in multiple cycles (at least three), indicating the potential of MHS as an alternative to costly commercial adsorbents for the removal of nitrates from wastewater

Modified Hazelnut Shells as a Novel Adsorbent for the Removal of Nitrate from Wastewater

The aim of the study was to prepare a novel adsorbent by chemical modification of hazelnut shells and evaluate its potential for the nitrate removal from model solutions and real wastewater. The characterization of the novel adsorbent, i.e., modified hazelnut shell (MHS) was performed. The adsorbent characterization included the analysis of elemental composition and the surface characteristics analysis by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The adsorption experiments (batch technique) were performed to investigate the effects of adsorbent concentration, contact time, initial nitrate concentration, and solution pH. The nitrate removal efficiency increased with the increase in MHS concentration and decreased with the initial nitrate concentration. MHS was found to be effective in nitrate removal over a wide pH range (from 2 to 10), and the highest amount of nitrate adsorbed was 25.79 mg g−1 in a model nitrate solution. Depending on the aqueous medium (model solutions or real wastewater samples), it was shown that both Langmuir and Freundlich adsorption isotherm models can be used to interpret the adsorption process. It was found that the kinetics are well described by a pseudo-second order model and the nitrate adsorption process can be controlled by chemisorption. The intraparticle diffusion model has been used to identify an adsorption-controlled process by diffusion mechanisms. Adsorption/desorption experiments in column confirmed that MHS could be successfully used in multiple cycles (at least three), indicating the potential of MHS as an alternative to costly commercial adsorbents for the removal of nitrates from wastewater

Post-projektna analiza – studija slučaja za linijski infrastrukturni objekat

Post-projektnu analizu čine sve aktivnosti čiji je cilj sagledavanje parametara kako je objekat izveden, uključujući i to u kojoj meri on ispunjava projektovane zahteve, kao i to u kom stepenu su sami korisnici zadovoljni “gotovim proizvodom”. Preduzeća koja podjednaku važnost pripisuju post-projektnoj analizi kao i samoj realizaciji projekta ne ponavljaju greške! U toku realizacije projekta “Rekonstrukcije i modernizacije deonice Gilje-Ćuprija-Paraćin, pruga Beograd-Niš”, započeta je izrada post-projektne analize. Način izrade i zaključci su prikazani u radu