Environmental protection and European Directive on packaging and packaging waste

5. simpozijum Hemija i zaštita životne sredine sa međunarodnim učešćem, 27-30. maj 2008, planina Tara, Srbija : 5th Symposium Chemistry and Environmental Protection with international participation, May 27-30, 2008, Mt. Tara, Serbi

Application of methyl methacrylate for pressing and machining of alumina green ceramics

The addition of methyl methacrylate (MMA) in the amount of 2 mas% in the alumina mixture improved the pressing of alumina and achieved excellent quality of machining of green compacts. The compressibility test determined the optimal pressing pressure of alumina with MMA of 60 MPa. The value of green densities was analyzed depending on applied pressure up to 150 MPa. The exceptionally smooth and shiny surface of green compact indicates good pressing of alumina with MMA. After pressing, the samples were thermally treated at 115 o C to activate the side groups of MMA polymer chains at a temperature slightly higher than the glass transition temperature (103 o C) of PMMA. This way was to improve the strength of the green compact. Compacts prepared with MMA had higher values of green density and lower values of sintered density, total and open porosity than compacts without MMA. After sintering at 1620 o C, the relative linear shrinkage was about 15% for the entire range of applied pressing pressures. The machining of the green compact enables the precise production of complicated forms of technical ceramics for the needs of many areas of the economy.X Serbian Ceramic Society Conference - Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts; September 26-27, 2022; Belgrad

Preparation and characterization of clay and diatomaceous earth based porous ceramics with boric acid as additive

Poste

Senzor na bazi mezoporozne silike za kolorimetrijsko određivanje boje Basic Yellow 28 u vodenim rastvorima

The textile industry is one of the largest water-consuming industries in the world. The wastewater generated by the textile industry is a major source of pollution, containing mostly dyes, but also detergents, and heavy metals. Since dyes can have a negative impact on the environment, human and aquatic life, it is really important to find proper solutions for removal of these pollutants from wastewater. In addition, special attention is given to the discovery of new and fast "in situ" methods for identification and quantification of pollutants from wastewater. In this paper, SBA-15, mesoporous silica material, was used as sorbent for removal of Basic Yellow 28 from aqueous solutions. In addition, colored SBA-15 after sorption process was subjected to image analysis, to evaluate if it was possible to quantify sorbed dye on sorbent based on intensity of SBA-15 coloration. The obtained results revealed that SBA-15 could remove 99% of dye within 5 min. The highest efficiency of dye removal was at pH8, using 200 mg of sorbent. According to the Langmuir isotherm model, the theoretical maximum sorption capacity was 909 mg/g. Image-Pro software confirmed that it would be possible to quantify sorbed dye onto SBA-15 with accuracy of 0.98. Overall, SBA-15 demonstrated to be efficient sorbent in removal of Basic Yellow 28 from water, but also to be potential carrier as a sensor for detection of colored pollutants in water.Tekstilna industrija je jedna od najvećih potrošača vode u odnosu na druge industrijske grane. Otpadne vode iz tekstilne industrije su jedan od glavnih izvora zagađenja i uglavnom sadrže boje, ali takođe i deterdžente i teške metale. Pošto boje mogu imati negativan uticaj na životnu sredinu, ljude i vodeni svet, važno je pronaći odgovarajuća rešenja za uklanjanje ovih zagađivača iz otpadnih voda. Pored toga, posebna pažnja je posvećena otkrivanju novih i brzih „in situ” metoda za identifikaciju i kvantifikaciju zagađivača iz otpadnih voda. U ovom radu kao sorbent za uklanjanje Basic Yellow 28 boje iz vodenih rastvora korišćen je SBA-15, mezoporozni silika materijal. Pored toga, obojeni SBA-15 nakon procesa sorpcije podvrgnuti su analizi slike, kako bi se procenilo da li je moguće kvantifikovati sorbovanu boju na sorbentu na osnovu intenziteta obojenosti SBA-15. Dobijeni rezultati su pokazali da SBA-15 može ukloniti 99% boje u roku od 5 minuta. Najveća efikasnost uklanjanja boje bila je pri pH 8, korišćenjem 200 mg sorbenta. Prema Langmuirovom modelu, teoretski maksimalni kapacitet sorpcije bio je 909 mg/g. Softver Image-Pro je potvrdio da je moguće kvantifikovati boju na SBA-15 sa tačnošću od 0,98. SBA-15 se pokazao kao efikasan sorbent u uklanjanju Basic Yellow 28 boje iz vode, ali i kao potencijalni senzor za detekciju obojenih zagađivača u vodi

The effect of acrylate on the properties and machinability of alumina ceramics

Effect of methyl methacrylate (MMA) as a binder and heating treatment were investigated to improve green alumina compacts machinability. Properties of green compacts and their corresponding sintered samples prepared with and without MMA were compared. Investigation of green and sintered properties was performed on samples compacted at applied pressures up to 150 MPa. After pressing, samples with MMA were thermally treated at 115oC. The intention was to enhance the polymerization of MMA at a temperature a little higher than the glass transition temperature (Tg = 103oC) of poly (methyl methacrylate). Green compacts with MMA had higher green density values than those without MMA. Sintered samples with MMA had lower values of sintered density and higher values of total porosity; after sintering, relative linear shrinkage was around 15 % for the whole range of applied pressures. The possibility of easily machining the green compacts with MMA produces great possibilities for application in many field