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Production of organic dyes has been constantly increasing in the last decades, hence their us-age leaves a huge environmental impact usually on aquatic biota. Wastewaters carrying dissolved dyes are toxic to all organisms existing in water, therefore such wastewater streams have to be ap-propriately treated before they can be released into the environment. Development of effective ad-sorbents, which can be used in wastewater treatment, is mandatory. Another concern in the produc-tion of sorbing materials is the formation of spent acids or bases since they are commonly used for the activation of adsorbents. Spent acid liquor produced during the activation of expanded vermicu-lite (EVer) is utilized as the start material for the preparation of layered double hydroxide (LDH-EVer) by the method of co-precipitation process at low supersaturation. The prepared adsorbent was characterized by Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy with X-ray energy dispersive spectroscopy (SEM-EDS). Fabricated material is utilized as an adsor-bent of methyl orange dye from aqueous solutions. During the experiments, contact time were varied and thus the rate of adsorption is determined. The obtained results show a high adsorption capacity of 63 mg g-1.

The presence of different organic pollutants in water leads to the need to apply different technologies and processes for their removal. Organic pollutants can cause several negative impacts on surrounding environment, inducing detrimental effects on living beings. Fungicides represent one of the biggest groups of crop protective agent with increased yearly consumption, frequently ending up in non-target organisms. Therefore, aim of this study was to determine the possibility of using two synthesized nanocatalysts Ag-P25 and Ce-P25 in several consecutive removal cycles of present pollutant in water. Catalysts were applied in process of photocatalytic degradation of fungicide thiophanate-methyl at atmospheric conditions. After each irradiation cycle, catalysts were collected, rinsed, dried, and applied in upcoming operational run. Fabricated catalysts were also likened to starter TiO2 material. After fifth cycle, FTIR and XRD characterization techniques were used for proving stability of materials. Obtained results show that Ce-P25 possesses (98%) better stability than Ag-P25 (96%), but base TiO2 (99%) has the best stability and efficiency after second cycle. Gathered findings can open a new way of employing photocatalysis as a process for treatment of polluted waters from various industries.

The jarosite type of sediment that occurs in the hydrometallurgical production of zinc represents an attractive research area for the valorization of lead. Intermediate products of zinc metallurgy were used for testing: untreated, roasted and water-washed roasted PbAg precipitate. After a detailed insight into the possibility of processing this type of sediment using the hydrometallurgical process, the choice of means for leaching the samples was made, and in the experimental research a solution of magnesium chloride hexahydrate (MgCl2 × 6H2O) was used. The thermodynamic analysis included the calculation of the standard Gibbs energy of chemical leaching reactions and the construction of the Eh/pH diagram of the stability of lead and accompanying metals in the investigated systems. By examining the influence, ratio of sample mass and volume of leaching agent, as well as leaching time, conclusions were reached about the possibilities of leaching Pb from intermediate products of zinc metallurgy. The optimal parameters of the leaching process in the tested systems were determined, i. e. it was shown that in all three tested samples the maximum leaching of lead is achieved at a concentration of MgCl2 × 6H2O of 4 mol/dm3, for a duration of 60 minutes, at a temperature of 80 oC and a solid:liquid ratio of 1:20.

Cilj ovog rada bio je prikaz modela fluktuacije azotnih jedinjenja u površinskim vodama usled akcidentnih situacija. Slučajno ispuštanje jedinjenja azota, konkretno veštačkih đubriva, ima veoma štetan uticaj na kvalitet vode i vodene ekosisteme. U ovom radu je navedeno nekoliko primera akcidentnih situacija ispuštanja azotnih đubriva u površinske vode, uključujući i akcident koji se desio u Republici Srbiji, kada je usled plovidbene nezgode, oko 1000 t veštačkog azotnog đubriva potonulo u reku Dunav. Svi ovi akcidenti ukazuju na značaj prevencije ili naknadnog umanjenja uticaja ovih jedinjenja na živi svet. U cilju prevencije budućih akcidenata i ublažavanja efekata već nastalih, potrebno je izraditi planove reagovanja u vanrednim situacijama. Za održivo upravljanje rečnim slivovima, ključno je razumevanje promena koje mogu izazvati transport, disperzija i transformacije zagađujućih materija, u ovom slučaju jedinjenja azota, u vodi. U te svrhe mogu se koristiti brojni matematički modeli, među kojima se izdvajaju predstavljeni modeli MONERIS, ADM i QUESTOR na rečnim slivovima u Engleskoj i Mađarskoj.

Releasing untreated or inadequately treated effluents into recipients (rivers, lakes, and oceans) can endanger aquatic ecosystems and drinking water sources. In order to eliminate harmful pollutants, wastewater must be treated, especially industrial wastewater enriched with nutrients. Phosphorus contamination can occur through a variety of different routes, such as wastewater treatment plant discharge (municipal and industrial), agricultural fertilizer losses from erosion, drainage, etc. The establishment of suitable wastewater treatment techniques is essential. The subject of this paper is the biological removal of nutrients (phosphorus) from wastewater, using unconventional methods of wastewater treatment - sequencing batch reactors (SBR) systems. Their modifications and the advantages such processes offer, compared to the standard activated sludge (AS) treatment that is the most often used, will be presented. Enhanced biological phosphorus removal methods that employ various microorganisms have been observed from the perspective of the method's effectiveness. Of all applied treatments for phosphorus removal, the most effective and the most often used was the accumulation of polyphosphates in the biomass itself. The purpose of this paper is to offer a brief review and theoretical essentials of environmental engineering techniques that can be applied in real industrial wastewater treatment plants.

Wastewater represents a major environmental pressure on the entire ecosystem. Pollutants in wastewater, such as dyes, can cause toxic effects on living beings. Therefore, it is necessary to develop new, efficient sorption materials that can remove the present pollutants and solve the pollution problem. The layered double hydroxides obtained by the co-precipitation process at low supersaturation were applied in the process of removing methanil-yellow color from aqueous solutions. During the experiments, parameters such as adsorbent mass, contact time, and temperature were varied. The obtained results show a high adsorption capacity of 74 mg g-1 and an endothermic nature during adsorption process.

The reserves of rich ores, from which the production of zinc by the existing conventional roasting-leaching-electrowinning process is technologically possible and economically justified, are decreasing year by year. For this reason, increasing attention has been directed towards researching the possibility of obtaining zinc from complex polymetallic ores with a low metal content, adhering to sustainable development goals following strict environmental regulations. Leaching procedures are commonly utilized for the processing of such mineral raw materials. As sphalerite is the widespread and most significant mineral of zinc sulfide, a large part of the research focuses on studying the behavior of sphalerite in the leaching process. This paper reviews the existing knowledge about the leaching of sphalerite in acidic solutions as well as the phenomena accompanying the dissolution process. Special attention is given to research related to the kinetics and mechanism of sphalerite oxidation in an acidic medium influenced by various oxidants, such as hydrogen peroxide, oxygen, dichromate ions, nitrate and nitrite ions, ferric and cupric ions, and others. All these results enable the development of new technological procedures to produce zinc from low-grade and complex ores while meeting increasingly rigorous environmental requirements.

Conventional wastewater treatment processes are increasingly difficult to fulfill strict standards of achieving the required quality. Therefore, it is necessary to apply processes that in an efficient and economically justified way reach the necessary limits in order to discharge wastewater into the recipient. The process of photolysis represents the degradation of the starting pollutant practically to water and carbon dioxide. The whole process takes place under the action of a UV lamp that imitated solar irradiation. The process is environmentally justified since, unlike some other advanced oxidation processes - AOPs, there is no use of additional, hazardous, chemicals which possibly results in the precipitates formation that are leading to further treatment. In this paper, photolytic degradation of pesticide thiophanate methyl was performed in doubled wall quartz reactor equipped with a thermoregulation system. Reaction was forced under Osram ULTRA VITALUX UV lamp (300W). Kinetics of photodecomposition process was followed by pseudo-first order. In certain time periods, specimens were sampled, filtered and monitored by UV spectrophotometer Shimadzu 1800 with an aim to determine the concentration of xenobiotic. Complete degradation of present xenobiotics was obtained after 240 min. With an aim to enhance the degradation process, hydrogen peroxide was added as a boosting agent which cause a shortening in demanded time (150 min) for complete degradation. Verification of the success of decomposition was confirmed by the obtained values of chemical oxygen demand (COD), which reveal that the established system has a basis for real application in industrial or municipal wastewater.

Cotton-based membranes, due to their exceptional biocompatibility and sustainability, have attracted considerable attention in various applications, especially in the field of bio and green technologies. This study investigates the biodegradation potential of cotton membranes modified with TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) radical and citric acid (CA), with the aim of improving their properties and facilitating environmentally friendly disposal. TEMPO radicals, in conjunction with the crosslinker citric acid, are incorporated into the cellulose structure through a novel modification process. The citric acid component acted as a plasticizer, increasing the amorphous parts of the cellulose and promoting enzymatic attack. The TEMPO radical, with its nitroxyl group, contributed to the oxidation of cellulose, further facilitating biodegradation. The biodegradation aspect of these modified membranes was investigated in controlled environmental conditions (Soil Burial test), simulating natural scenarios (humidity, influence of enzymes, and bacteria). Biodegradation parameters such as weight loss, structural changes, and degradation kinetics were examined during 90 days. Characterization of the structure was performed using FTIR and SEM methods. Our findings suggest that cellulosic membranes possess complete (100%) biodegradability after 70 days compared to unmodified membranes. Obtained result shed light on the potential of membranes modified in this way as sustainable and biodegradable alternatives in various applications. The results emphasize their ecological nature and ability to reduce environmental stress. Such cellulose-based materials promise a much greener future in biotechnology, healthcare, and environmental protection.

Pollution of water with toxic substances is increased. Therefore, innovative solutions for their treatment are essential. This paper represents results from an adsorption study where novel synthesized biobased membranes were applied in the removal of dye metanil yellow from wastewater solution. Batch adsorption tests were applied, where the different operational impacts including contact time, initial pollutant concentration, temperature, etc. were varied. Fabricated membranes were based on waste cellulose tobacco boxes modified by amino acid lysine with an aim to increase sorption capacity toward azo dye. Structural properties were examined by FE-SEM and ATR-FTIR techniques. The activities of materials prior to and after modification were compared. It was found that the modified material achieved a better sorption capacity. The resulting adsorption capacity for the improved membrane was 65 mg/l compared to 51 mg/l, at 45°C, for the base cellulose membrane. The kinetics of the process follows a pseudo second-order curve. The best agreement of the correlation factor R2 was shown with the Freundlich isotherm. The obtained results show the success of the modification with a good sorption capacity of the material towards the target pollutant. Overall, it can be concluded that the modified membranes lay a good foundation for potential application in industrial dye wastewater treatment systems.

The presence of arsenic in drinking water above the permissible limits is one of the current problems facing modern engineers in the field of separations and it has not yet been satisfactorily resolved, because the permissible concentrations of arsenic in drinking water are constantly reduced by the World Health Organization (WHO). Among the various processes for arsenic removal, adsorption has a special place as one of the most efficient and cheap process. Many natural and artificial materials are tested for adsorption processes, and adsorption on metal powders is particularly interesting because they represent adsorbents with fast kinetics and relatively high adsorption capacities. However, the application of powder adsorbents is difficult due to their separation from the mixture after adsorption. In order to solve that problem, metal powders may be immobilized into particles obtained by gelling natural polymers. In this way, it is easier to separate the adsorbent from the mixture, however this must be achieved without losing the adsorption capacity and rate compared to pure metal powders. In this study, the use of metal oxide (iron oxide nanoparticles) immobilized within the alginate gel showed good potential for arsenic (V) ions removal. The obtained results showed that arsenic adsorption by obtained composite has fast kinetic, following pseudo-second-order model, and that it is conducted in several steps, according to the Weber-Morris model. It was suggested that external diffusion is the dominant mechanism at the beginning of the arsenic adsorption, followed by intraparticle diffusion. The obtained results confirmed that gelling with alginate did not significantly affect the adsorption process, that is, it does not interfere with the adsorption capacity of metal oxides, which is a very important factor. Arsenic (V) removal was successfully performed using the investigated composite.

Nickel pollution of water induces several problems for the environment. The purpose of this paper was to investigate the adsorption of Ni2+ ions on fabricated biomembranes. The proposed adsorbent was prepared from epoxy and amino-functionalized waste cellulose fibers, able to participate in cross-linking with amino acid lysine - wCell/Mn-Fe_LDH. The prepared material underwent preliminary structural characterization by Fourier-transform infrared spectroscopy. In a batch system, the influence of pH, contact time, temperature, and initial concentration on adsorption efficiency was investigated. The effectiveness of the membrane was demonstrated by acceptable adsorption capacities of 40.49 mg g-1 obtained for Ni2+ at 45°C. The kinetic study, using the Weber-Morris model, indicates intraparticle diffusion as the rate limiting step. Adsorption mechanism physisorption was proposed based on thermodynamic behaviors. The outcomes demonstrated that environmentally friendly sustainable technology has been successfully developed.

Growing industrialization and non-renewable resource depletion have a huge impact on alternative clean up technologies development, inducing investigation of the renewable, low-cost waste materials. Recently, lignocellulosic waste biomass, generated at a large scale by different industries, appeared as an attractive feedstock worldwide, due to its abundance, availability, multi-functionality and low cost. Since the fruits production has increasing trend all over the world, generation of lignocellulosic waste such as fruit stones (that represent approximately 1/5 of the total fruit mass) became a great environmental threat. In order to minimize negative impact on the environment, avoid greenhouse gasses emissions and help in resource depletion by its renewable nature, it is necessary to explore its performances regarding its wide application potential. Thermo-chemical conversion of lignocellulosic biomass in oxygen limited conditions, in order to get biochar, has received a lot of attention recently. The biochar production requires lower energy inputs and less expensive technology compared to activated carbon (estimation is that production cost of activated carbon are six times higher than biochar costs). In this paper, waste peach stones biomass was effectively converted into biochar at 500 °C under inert (Ar) atmosphere. Pyrolysis was performed in Nabertherm 1300 muffle furnace for residence time of 1.5 h, with a heating rate of 10 °C/min, while Ar was circulated through the sample at a rate of 100 mL/min. The raw biomass (PS) and obtained biochar (PS-B) with particle size 0.1 mm < dp < 0.5 mm, were characterized by Scanning Electron Microscopy (SEM), Fourier transform infrared spectrometry (FTIR) and Raman spectrometry to understand physicochemical changes which have been occurred after pyrolysis. SEM analysis revealed the increased surface area due to the visible augmentation of pores and roughness. FTIR analysis showed that many bands present in native biomass c

Worldwide pollution induces a negative impact on the complete environment. Modern societies are becoming more involved in developing and implementing climate change adaptation policies as a result of the enormous hazards that climate change poses to human safety worldwide. One of the biggest problems that highly affects climate change is plastic pollution. Also, the utilization of a linear economy prevents the opportunity of solving mentioned problem. Hence, a major component of the strategy for tackling plastic pollution and trying to decrease global weather changes is an implementation of a circular economy. Plastic has to be reduced, reused, and recycled since its widespread consumption has put environmental protection at risk. PET, also known as polyethylene terephthalate, is a prominent polymer material used for the production of packaging, particularly plastic bottles. The majority of PET-based products are made using raw materials supplied from fossil fuels. However, methods based on biobased materials and recycling- modified products for obtaining novel products from waste PET have fewer greenhouse gas (GHG) emissions than the traditional method. Therefore, the subject of this paper is the innovative technology for the fabrication of materials by PET recycling. Obtained monomer units - glycolysates were acquired by PET depolymerization by inducing greener solutions. The resulting glycolysate was structurally modified with maleic anhydride and finally with 2-octanol to obtain a novel plasticizer. The physicochemical characterization of the obtained plasticizer, performed by infrared spectroscopy with Fourier transform (FTIR) and NMR spectroscopy, confirmed structural modifications. The mechanical characteristics of the final product were tested after the plasticizers had been combined with bitumen at a range from 1 to 10 wt.% concentration. In addition, other PET recycling techniques will be presented and discussed. By comparing them, it will be determined wh

In oxygen converters, molten iron from the blast furnace is refined with steel waste under oxidizing conditions [1]. The injected oxygen passes into the iron melt, after which it reacts with the impurities. Analysis of exergy losses clearly indicates the place of energy losses in the observed process, so a detailed analysis can influence the improvement of a complex process [2]. Exergy losses occur due to technological imperfections such as heat dissipation or friction and system irreversibility according to the second law of thermodynamics [3]. The concept of exergy can be used for a better understanding of the feasibility of a process, as well as for the techno-economic analysis of the process at different variations of input/operating parameters. In this work througtful calculation of exergy oxygen convertor was done. According to the obtained data, out of a total of 972.2 MJ of thermal energy, which is released by exothermic reactions in the refining process, 817.5 MJ is pure exergy and can be used, the rest is anergy that arises due to irreversibility.

Powdered gypsum products were the standard for agricultural gypsum for many years, but as growers look to maximize their return on investment, they are increasingly turning toward pelletized gypsum – a premium alternative. Pelletized gypsum offers several significant advantages over other forms of gypsum such as powdered or ultra-fine gypsum, these advantages will be discussed in the paper. This has led to increased grower adoption and a greater demand for fertilizer and soil amendment producers to offer gypsum in a pelletized form. Producers are also finding that they stand to gain a few benefits from offering a pelletized product as well.

Procesi prečišćavanja otpadnih voda, koji su do sada korišćeni, pokazuju ograničenu mogućnost efikasnog uklanjanja nutrijenata. Ispuštanje netretiranih ili nedovoljno tretiranih otpadnih voda u recipijente, kao što su reke, jezera i mora, može ugroziti akvatične ekosisteme izazivanjem procesa eutrofikacije. Stoga je neophodno tretirati otpadne vode, kako sanitarne tako i industrijske, i ukloniti iz njih štetne materije. U ovom radu je prikazano biološko uklanjanje azota kao nutrijenta iz otpadnih voda primenom nekonvencionalnih metoda tretmana otpadnih voda – MBBR (eng. Moving bed biofilm reactor). Biće prikazane njihove modifikacije i prednosti koje ovakvi procesi nude u odnosu na standardni tretman aktivnim muljem, koji se najčešće koristi. Prednosti korišćenja MBBR reaktorskih sistema se ogleda u mogućnosti njihove primene u tretmanu različitih tipova industrijskih otpadnih voda, mogućnosti upotrebe nosača u konsekutivnim reakcijama prečišćavanja što uzrokuje niže operativne troškove procesa i time ih čini veoma pogodnim za denitrifikaciju otpadnih voda. Unapređeni procesi biološkog uklanjanja azota pomoću različitih tipova mikroorganizama biće praćeni sa stanovišta efikasnosti samog procesa. Cilj ovog rada jeste predstavljanje inženjerskih osnova u primeni ovih procesa u daljim eksperimentalnim istraživanjima.

Environmental management demands innovative techniques for its protection and treatment. The essential agreement of the modern world is to overcome every issue in a sustainable way. The two major financial problems in this area are water pollution and material corrosion. Persistent, organic compounds such as pesticides have devastating effects on the water ecosystem. This problem can be solved by applying advanced treatment processes (ATPs) like membrane separation and photocatalysis. Additionally, the corrosion of metal materials needs to be prevented to preserve natural resources and reduce environmental concerns. Therefore, researchers are trying to develop tunable, multifunctional materials with broad applications. Employed materials in these operations must fulfill high criteria, like durability, stability, and chemical and optical activity, to make specified processes efficient and viable. Electroconductive polymers (ECPs) can meet the aforementioned standards. The most used ECP is polyaniline (PANI), due to its catalytic and electrochemical performances. These two properties are beneficial for both water purification and anticorrosion applications. The objectives of the paper are to represent various PANI-based composites utilized in the removal of different classes of pesticides during wastewater treatment by adsorption or photocatalytic degradation. Further corrosion inhibition, utilizing PANI-based inhibitors, will be discussed as well.

In this study, iron oxide nanoparticles immobilized within alginate gel exhibited promising potential for the removal of arsenic (V) ions. The preparation of the polymer-oxide composite was achieved by the ionic crosslinking of an alginate/iron oxide solution with a calcium (II)ions solution. The maximum amount of arsenic adsorbed by the investigated composite under the experimental conditions was slightly above 26 mg/g in 120 min. The results indicated that arsenic adsorption by this composite material follows a fast kinetic profile, adhering to a pseudo-second-order model. The adsorption process occurs in multiple stages, as suggested by the Weber-Morris model, with external diffusion dominating initially, followed by intraparticle diffusion. Importantly, the results confirmed that the use of alginate gel does not significantly impact the adsorption process, preserving the adsorption capacity of the metal oxides. Overall, the investigated composite successfully removed arsenic (V) from the solution, addressing a critical issue in water treatment. (1) (PDF) Application of Natural Polymer and Metal Oxide Composite for Removal of Arsenic(V) Ions from Aqueous Solutions. Available from: https://www.researchgate.net/publication/378821317_Application_of_Natural_Polymer_and_Metal_Oxide_Composite_for_Removal_of_ArsenicV_Ions_from_Aqueous_Solutions [accessed Mar 12 2024]."

In this study, iron oxide nanoparticles immobilized within alginate gel exhibited promising potential for the removal of arsenic (V) ions. The preparation of the polymer-oxide composite was achieved by the ionic crosslinking of an alginate/iron oxide solution with a calcium (II) ions solution. The maximum amount of arsenic adsorbed by the investigated composite under the experimental conditions was slightly above 26 mg/g in 120 min. The results indicated that arsenic adsorption by this composite material follows a fast kinetic profile, adhering to a pseudo-second-order model. The adsorption process occurs in multiple stages, as suggested by the Weber-Morris model, with external diffusion dominating initially, followed by intraparticle diffusion. Importantly, the results confirmed that the use of alginate gel does not significantly impact the adsorption process, preserving the adsorption capacity of the metal oxides. Overall, the investigated composite successfully removed arsenic (V) from the solution, addressing a critical issue in water treatment

Zagađenje životne sredine, pre svega površinskih i podzemnih voda, upotrebom pesticida usled privredne delatnosti ljudi predstavlja sve veći problem. Primena sredstava zaštite bilja u koncentracijama koje su veće od dozvoljenih, dovelo je do akumulacije i uvećanja koncentracija ovih zagađujućih materija u vodama. Stoga je potrebno primeniti različite procese za njihovo uklanjanje, među kojima fotokataliza zauzima posebnu pažnju. Fotokataliza pripada grupi naprednih oksidacionih procesa (eng. Advanced oxidation processes – AOPs). Naše istraživanje odnosilo se na mogućnost fotokatalitičke razgradnje fungicida tiofanat-metila upotrebom rutil TiO2 katalizatora pod uticajem UV zračenja. Ispitan je uticaj eksperimentalnih parametara na proces, kao što su masa katalizatora, koncentracija rastvora pesticida kao i rastojanje UV lampe od rastvora, što bi trebalo da pomogne u boljem razumevanju fotokatalize kao procesa u konkretnom sistemu. Utvrđeno je da su optimalni uslovi razgradnje bili pri koncentraciji 5 mg/L pesticida i 0,06 g/L katalizatora, uz konstantu brzine od 0,031 min-1. Stepen uklanjanja pesticida iznosio je 50% nakon 45 min, dok je za potpunu degradaciju bilo potrebno 120 min.. Optimizovani proces degradacije pesticida pokazuje da primenjeni proces ima zadovoljavajuću efikasnost i da može zameniti konvencionalne tehnike tretmana otpadnih voda.

Environmental pollution by wastewater represents one of the greatest challenges nowadays. The solution for this issue requires implementation of novel treatment methods. Therefore, enhanced techniques so-called Advanced oxidation processes (AOPs) are gaining increasing attention. Photocatalysis is a process based on the use of different types of irradiations on a pollutants adhered on a catalyst, driven by formation of radicals and oxidative species on the catalyst surface. Modern agricultural practice relies on use of different classes of pesticides, and to its, often, uncontrolled and excessive use. It leads to their widespread in the environment, with frequent detection in waterbodies and soil. Thiophanatemethyl (TPM) is benzimidazole fungicide, used in control of diverse groups of phytopatogenic fungus [1]. Specifically efficient and economically viable catalysts are TiO2-based. Multiphase catalysts showed better results in the degradation of various pollutants, so TiO2 P25 (Degussa) was used as a material that boosts photocatalytic decomposition. In order to advance and fasten the reaction, the surface of TiO2 P25 was decorated with cerium (IV) oxide [2]. Surface and photochemical properties of newly obtained material are characterised by HR - TEM, HAADF - STEM; FTIR and UV - DRS methods. In this study, the photocatalytic degradation of thiophanate-methyl (TPM) in the presence of CeO2 - P25 was investigated. Different experimental conditions were varied, such as the concentration of the pesticide solution and the mass of the catalyst. Monitoring of the pesticide concentration in the reaction system was based on the decrease in absorbance using a Shimadzu 1800 UV spectrophotometer. Results of textural and structural analyses prove decoration of P25 surface with particles of cerium (IV) oxide uniformly. Synthesised nanocatalyst CeO2-P25 has lower band gap energy (2.90 eV) then P25 (3.30 eV). The optimal experimental conditions were obtained using 0.07 g/L of CeO2

Suština ovog Tehničkog rešenja odnosi se na postupak proizvodnje novog protivpožarnog materijala sa plastifikatorima iz recikliranog poli(etilen terefatalata) koji se koristi za izradu prstenova za cevi kao pasivne zaštite od širenja požara. Tehnološki postupak se sastoji iz dve faze. Faza (I) se odnosi na mešanje polivinilhlorida (PVC K70 i PVC K58), sa plastifikatorima kao što su diizononil ftalat (DINP), tri(krezil fosfati) (TKP) (smeša tri(p-krezil fosfat) (TpKP), tri(m-krezil)fosfat (TmKP), tri(o-krezil)fosfat (ToKP) ili čiste komponente), kao i plastifikatori koji su dobijeni iz recikliranog poli(etilen tereftalata) (PET) procesima depolimerizacije PET-a pomoću etilen glikola (PET/EG), propilenglikola (PET/PG) koji se takođe modifikuje pomoću anhidrida maleinske kiselime (MA) i masnih kiselina izolovanih iz sojinog ulja, PET/PG/MA/MKSU, ili samo pomoću MKSU, PET/PG/MKSU, epoksidovano sojino ulje (ESU), 1-heksadecen ili MES, MESU, MELU, MESuU ili MEKU), azodikarbonamid (ADC) i akrilatna emulzija (Ecrylic) a sredstva za ekspandiranje: ekspandirani grafit (EkG), i njegove zamene PET/PG/MA/MKSU/TA, proizvoda dobijenih modifikacijom taninske kiseline (TA) sa PET/PG/MA/MKSU ili PET/PG/MKSU uz korišćenje kiselog katalizatora (KK-SO3H), se dodaje ili u topli mešač ili tokom transporta viskozne mase u ekstruder pomoću dozera sa kontrolisanim protokom pri čemu se masa homogenizuje i profiliše u željeni oblik. Druga faza se odnosi na homogenizovanje mase u ekstruderu i to u prvoj zoni je vreme zadržavanja 30 s - 15 min na temperaturi 90 - 140 ºC, u drugoj zoni 10 s - 10 min na temperaturi 100 - 150 ºC i trećoj zoni vreme zadržavanja 1 s - 60 s na temperaturi 110 - 220 ºC pri čemu se profilisanje materijala vrši korišćenjem alata na izlazu ekstrudera u cilju dobijanja traka širine 1 - 500 mm i debljine 1-100 mm

Wastewater management covers various techniques developed to provide purified water that would do minimum harm to the environment. Applying adsorption leaves a saturated adsorbent that should be regenerated or stabilized so it can’t release pollutants into the environment. Lead, one of the most toxic pollutants, can be efficiently removed utilizing the adsorption process. After the consecutive adsorption and desorption processes, the lead must be processed to significantly reduce and prevent the risk to human health and environmental pollution. As one of the most efficient technologies for treating this toxic pollutant, stabilization has been tested by converting a desorbed lead to its salt leadphthalate (LP). Obtained LP is used as a component in the production of construction materials and composites with unsaturated polyester resins (UPR). A standard leaching test (Toxicity Characteristic Leaching Procedure - TCLP) was performed to determine the toxicity of the waste material used as an additive. The concentration of leached lead from the construction material with the addition of Ca(OH)2 can be as high as 54 mg/L, which significantly exceeds the permitted limits. After adding cement, lead concentration is lower - 13 mg/L. The acquired results from the sample with UPR show that the concentration of released lead is as low as 0.01 mg/L. Such results indicate complete crosslinking of the UPR and strong binding of the lead ions. Applying the S/S technique together with the utilization of UPR would be an environmentally friendly operation and easily applicable procedure for stabilizing Pb2+.

Recent mankind demand for electronic devices is in constant upgrowth, those devices always contain printed circuit boards (PCB) which are mainly constructed of plastics, semiconductors and decent content of various metals. Hence, in the end-of-life of those products, it is highly recommended to recover those materials or functionalize those waste into other products or feed materials, in order to lessen their harmful impact on the environment. One of the promising processing procedures is hydrometallurgical treatment, since it is cost-effective and simple. In order to recover metals as aqueous soluble salts, crushed and milled PCB is air-pyrolyzed and obtained powder is processed as start material in leaching experiments. The use of concentrated aqua regia led to the passivation of solid material and consequently impede the leaching process. Dry-digestion leaching using concentrated sulfuric acid partially leached some metals. The highest leaching rate (≥70 %) has been achieved using diluted sulfuric acid (for Al, Ni, Fe, Co, and rare-earth) and copper yield was highest utilizing 2 M H2SO4 + 3 M H2O2; S/L = 0.1 g/ml. While sulfuric acid has accomplished some results for enumerated leachates, it achieved limited success for leaching Ba, Pb, Ag, Au, Pt and Pd. Overall findings imply that hydrometallurgical procedures may be used but only together with previous separation techniques. That approach would increase overall leaching with oxidizing agents and enable leaching of noble metals.

Current demand on adsorbent materials is in constant growth, hence scientific society is in ceaseless research subjecting cheap and optimal adsorbent. Abundant raw materials which may be utilized as adsorbent of cation species are mica minerals, and vermiculite as one of them is widely examined. Since wastewater may contain anion or/ and non-ionic pollutants it is needed to functionalize adsorbent so it may attract those species as well. Goethite and ferrihydrite are potential candidates for such modification since they: have large specific surface area (SSA), possess hydroxide group and they are not toxic to the environment. Goethite/ expanded vermiculite (Goe/EV) and ferrihydrite/ expanded vermiculite (Fer/EV) are successfully prepared and those composites have showed better adsorption related chemical properties than expanded vermiculite (EV) itself. Utilizing BET methodology, it is determined that Fer/EV possess five-time larger SSA than EV, while Goe/EV is two times larger. Measuring cation exchange capacity (CEC) it is determined that modified samples have only ~10% smaller values of CEC. Summary, both composites have shown higher affinity toward cationic dye, malachite green and also showed their adsorbent potential toward anionic dye, tartrazine. Thanks to facile preparation of such materials and its cost, it may be concluded that they are prospective choice as adsorbents, in first order of heavy metals and dyes.

Conventional wastewater treatment processes are increasingly difficult to fulfill strict standards of achieving the required quality. Therefore, it is necessary to apply processes that in an efficient and economically justified way reach the necessary limits in order to discharge wastewater into the recipient. The process of photolysis represents the degradation of the starting pollutant practically to water and carbon dioxide. The whole process takes place under the action of a UV lamp that imitated solar irradiation. The process is environmentally justified since, unlike some other advanced oxidation processes - AOPs, there is no use of additional, hazardous, chemicals which possibly results in the precipitates formation that are leading to further treatment. In this paper, photolytic degradation of pesticide thiophanate methyl was performed in doubled wall quartz reactor equipped with a thermoregulation system. Reaction was forced under Osram ULTRA VITALUX UV lamp (300W). Kinetics of photodecomposition process was followed by pseudo-first order. In certain time periods, specimens were sampled, filtered and monitored by UV spectrophotometer Shimadzu 1800 with an aim to determine the concentration of xenobiotic. Complete degradation of present xenobiotics was obtained after 240 min. With an aim to enhance the degradation process, hydrogen peroxide was added as a boosting agent which cause a shortening in demanded time (150 min) for complete degradation. Verification of the success of decomposition was confirmed by the obtained values of chemical oxygen demand (COD), which reveal that the established system has a basis for real application in industrial or municipal wastewater.

Numerous electronic devices are put out of use every day, and most of them have printed circuit boards (PCBs) that are lased and imbued with various precious and valuable metals in abundant amounts. This makes PCB an unexploited resource of the future from whom many metals such as Cu, Zn, Sn, Al, Li, Co, Nd, Pd, Pt, and Ba can be extracted. Since leaching plastic polymers can lead to the vaporization of toxic fumes, to avoid this the PCB are pyrolyzed. The PCB is crushed and the pyrolyzed product is a powder that can easily be separated into metallic and nonmetalic fractions. The aim of this work is to investigate the influence of ultrasound sonification on the nitric acid leaching of pyrolyzed printed circuit board (PPCB) powder. The impact of ultrasound sonification had a positive effect on the leaching degree for all investigated metals except for Cobalt. The biggest difference in leaching degree was for Lithium while the smallest was for platinum. Because of the complexity of the PPCB powder system overall, the measurement of oxidation-reduction potential (ORP) didn’t yield any insight into the leaching mechanism since the measured values mainly followed the expected trend due to nitric acid degradation.

Due to the rapid development of industry and growth of population, water consumption is increased. Beside this, releasing of xenobiotics, which represent significant pollutants into watercourse, like heavy metal ions, pesticides, paints, and solvents, made this problem much bigger. Therefore, they can enter into aquatic organisms directly from industrial plants or into human bodies indirectly through agricultural products. New technologies, including photocatalytic decomposition, are necessary for wastewater treatment as a highly efficient and low-cost process. Photocatalysis implies the degradation of various types of harmful organic substances to simple molecules such as CO2, SO2, ions, and water. The applied process has no detrimental effect on the environment and does not require additional chemicals for precipitation of the products. In this work, photodegradation of the pesticide difenoconazole (DFC) using a TiO2-based photocatalyst was examined using doubled wall thermoregulated quartz reactor. As a replacement for UVC radiation, solar imitated Ultra Vitalux (UV) lamp (300W) was used. Determination of DFC concentration was performed using a UV method. Degradation kinetics follows pseudo-first order. After 120 minutes, the DFC was completely degraded. Chemical oxygen demand (COD) also confirmed that successfully indicating that this process can be used in treating of industrial wastewater.

The environmental pollution by dyes has become an important concern due to the harmful effects on human health and entire ecosystem. In this study, bentonite immobilized in calcium-alginate (ImB) was studied as a sorbent for the Brilliant Green (BG) removal from aqueous solutions. The prepared composite sorbent was characterized by pHpzc, SEM and EDX. The sorption kinetic was best fitted by the pseudo-second-order model and simultaneously followed the film diffusion and intra-particle diffusion model during the sorption. This study proved that ImB might be an efficient sorbent for removing dyes from aqueous solutions.

Due to the increased pollution of waters, the general interest is to put this issue in the foreground, as one of the biggest problems of modern society. Following that, there is a need for the development of various technologies for their purification, as well as their constant improvement from the point of cost-efficiency of the process. Because of that, various techniques called ‘’advanced oxidation processes’’ are applied to remove pollutants from wastewater. They differ in the mode of action and application in specific cases of water pollution (i.e., the origin and type of treated wastewater). The following techniques are most commonly used: ozonation, ultrasound (US), UV radiation, and different combinations of them: ozonation with US, UV radiation with various catalysts, ozone with hydroxide-peroxide, etc. Before the advanced processes, the application of standard wastewater treatments (such as coagulation, flocculation, sedimentation, and filtration) was performed to optimize the applied treatment, as well as to assess the increase the overall efficiency of so-called ‘’coupled technologies’’. In this study, the wastewater samples originating from the armor industry were treated firstly by coagulation, and then with a combination of ozone and US. The purification efficiency was analyzed by reducing the concentration of heavy metals (Pb2+, Cd2+) using atomic absorption spectroscopy (AAS). The concentration of organic pollutants was followed by the values of chemical oxygen demand (COD) and biochemical oxygen demand (BOD5). The removal degree of metals were over 70%, and organic compounds were 95%). Based on the obtained results, combining the conventional and advanced wastewater treatment, the optimal purification solution was determined.

The aim of this paper is to investigate the application of modified lignin-based adsorbent for successful removal of dichromate ions and sodium diclofenac (DCF) from aqueous solutions by adsorption. Modification of lignin-based adsorbent (LBA) was performed by inverse suspension copolymerization with branched poly (ethylene-imine) using epichlorohydrin as a crosslinker. After that, the functionalization of LBA was performed by chemical binding of amino modified nanoparticles of manganese (IV) oxide, in order to improve the adsorption properties. Characterization of LBA-MnO2 microspheres was performed using FT-IR spectrometer, Scanning electron microscopy, BET/BJH analysis. The adsorption process was performed in a batch adsorption system. The results were obtained with the help of kinetic and corresponding equilibrium adsorption isotherms. The maximum adsorption capacity for the removal of Cr2O7 2- ions and DCF was obtained using the Langmuir model and amounts to 88.4 mg g-1 and 52.8 mg g-1 at 45 °C, respectively. Adsorption kinetics was described using a second-order pseudo model. Based on thermodynamic parameters, it was concluded that the adsorption process is an endothermic and spontaneous. Based on the obtained results, LBA-MnO2 material possess very good adsorption properties.

Pollution of water presents one of the biggest problems of modern society. Pesticide production, usage and release, as well as their persistence in the environment, have detrimental effects on the aquatic and non-target species. Therefore, it is necessary to apply treatment techniques in order to prevent these negative consequences. The processes used so far do not have the necessary efficiency to optimally solve this problem. Hence, plenty of advanced oxidation processes (AOPs) has been developed, among which photocatalysis has stood out. Thus, photocatalytic degradation of fungicide thiophanate-methyl by using recently synthesized catalyst Ag2O/TiO2 was considered. The effect of the various parameters, such as catalyst amount, fungicide concentration, and also the distance of the lamp from the photocatalytic reactor was studied. The obtained photocatalyst was examined using Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), as well as Diffuse reflectance spectroscopy (DRS). Photocatalytic assays employing Ag2O/TiO2 catalyst with the concentration of 0.065 g/l yielded the best results. The degradation rate constant was measured as 0,040 min-1 by observing values of absorbances from the UV spectrophotometer Shimadzu 1800. Under the optimal conditions, the complete disappearance of 10 mg/l of fungicide occurred within 2 h by using Ag2O/TiO2. However, the limitation of the applied process is reflected in the volume of wastewater that can be treated, while making it economically viable. Obtained results show that synthesized catalysts pose a great ability to effectively decompose thiophanatemethyl under UV light.