2 nd International Conference “The Holistic Approach to Environment“

The Association for Promotion of Holistic Approach to Environment from Sisak, with the co-organization of the University of Zagreb Faculty of Geotechnical Engineering, University of Applied Sciences Velika Gorica, the international association Balkan Environmental Association and Sisak-Moslavina County, organized the second international conference “The Holistic Approach to Environment”, which was held on May 28, 2021. The conference was originally planned to be held on May 20 - 21, 2020 in Sisak. Due to the pandemic caused by the coronavirus and the devastating earthquake that hit Sisak and the surrounding towns, the organizers postponed the conference on several occasions, and finally decided to hold it online. The fact that the selected papers from the 2nd international conference "The Holistic Approach to Environment" are published in Textile Journal also contributes to the aforementioned. Therefore, on behalf of the organizers and co-organizers of the conference, I would like to especially thank the editorial board of Textile Journal for their support and help in promoting the conference "The Holistic Approach to Environment”

Environmentally friendly waste for wastewater treatment

In this paper, the adsorption properties of two wastes from the metallurgical industry were studied: waste after shot blasting of the castings and waste moulding mixture, and waste from the wood industry, i.e. oak sawdust. A solution of Cu(II) ions was used as the adsorbate. Experimental data have shown that the waste from the metallurgical industry can be used as an adsorbent for removal of Cu(II) ions from wastewater. For oak sawdust, it could not be confirmed with certainty whether it had adequate adsorption properties due to the release of substances that lead to the coloration of the adsorbates. Lagergren\u27s and Ho\u27s model was used to describe the adsorption kinetics of the system waste moulding mixture/Cu(II) ions and waste after shot blasting of the castings/Cu(II) ions. It was concluded that both systems are better described by Ho\u27s model, i.e. that the adsorption kinetics in both systems take place according to pseudo-second order reactions

II. međunarodna konferencija „Cjeloviti pristup okolišu“

Udruga za promicanje cjelovitog pristupa okolišu iz Siska uz suorganizatorstvo Geotehničkog fakulteta Varaždin, Veleučilišta Velika Gorica, međunarodne udruge Balkan Environmental Association i Sisačkomoslavačke županije organizirala je drugu po redu međunarodnu konferenciju „Cjeloviti pristup okolišu“ koja je održana 28. svibnja 2021. godine. Održavanje konferencije je prvotno bilo predviđeno za 20. i 21. svibnja 2020. u Sisku. Zbog pandemije uzrokovane koronavirusom i razornog potresa koji je pogodio Sisak i okolne gradove organizatori su u nekoliko navrata odgađali konferenciju, kako bi se na kraju odlučili za online održavanje. Zanimljiv sadržaj konferencije potvrđen je odabirom radova za objavu u časopisu Tekstil u svešćići posvećenom ovoj konferenciji

“Green” adsorbents in the wastewater treatment service

In this study, the adsorption of acetic acid on the so-called "green" adsorbents was studied. Waste materials, i.e. eggshells and coffee grounds were used as adsorbents. In addition, activated carbon was used to compare the adsorption efficiency with "green" adsorbents. The obtained results showed that the equilibrium time of all studied adsorbents is achieved in 30 minutes. By comparing the adsorption efficiency of acetic acid on the tested adsorbents, it was shown that their use as cheap adsorbents under the tested conditions is possible. The coffee grounds showed a relatively high adsorption efficiency, very similar to the adsorption efficiency obtained when using the commercial and most commonly used adsorbent, i.e. activated carbon

PROPERTIES OF THE CHEMICALLY ACTIVATED CARBON ANODE DUST

Ugljična anodna prašina (UAP) otpadni je materijal pri proizvodnji aluminija. Kemijski sastav UAP određen je metodom apsorpcijske spektrometrije (AAS), a mineraloški sastav metodom difrakcije rendgenskog zračenja (XRD). Površinska svojstva (specifična površina, prosječni promjer pora i ukupni volumen pora) određeni su Brunauer Emmett Telleorovom (BET) metodom i Barrett-Joyner-Halendainom (BJH) metodom. Mikroskopska ispitivanja provedena su pretražnom elektronskom mikroskopijom (SEM). Sva su ispitivanja provedena prije i nakon kemijske aktivacije UAP s KOH, ZnCl2 i organskim kiselinama (octenom i limunskom). Dobiveni rezultati pokazali su pozitivan utjecaj kemijske aktivacije na kemijska i strukturna svojstva ugljične anodne prašine kao potencijalnoga jeftinog adsorbensa.The carbon anode dust (CAD) is waste material of the aluminium production industry. The chemical and mineralogical composition of CAD was examined by atomic absorption spectroscopy (AAS) and the X-ray diffraction method (XRD), respectively. Surface area properties (specific surface area, average pore diameter, total pore volume) are determined by the Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods. Microscopic observation was conducted using scanning electron microscopy (SEM method). All of investigations were performed before and after chemical activation of CAD by KOH, ZnCl2 and by organic acids (acetic and citric). The results obtained suggest the positive effect of chemical activation on the chemical and structural properties of carbon anode dust as a potentially low-cost adsorbent

Procjena broja nodula i nodularnosti u odljevcima od nodularnog lijeva korištenjem toplinske analize

The effect of parameters which are identified and measured by thermal analysis on the nodule count and nodularity in ductile iron castings was analyzed in this paper. The obtained results show that the nodule count and nodularity increases with increasing the temperature of eutectic undercooling (TEP) and graphite factor 1 (GRF 1) and decreasing recalescence (TR), graphite factor 2 (GRF2) and value of the first derivative of the cooling curve at TS (d/dt TS). The processing of obtained results was performed by multiple regression analysis. Based on the measured thermal parameters, models for estimation of the nodule count and nodularity were established. The high correlation coefficients between the measured and the estimated values of the nodule count (nodularity) confirm that there is a tight correlation between the thermal parameters of ductile iron melt and microstructural features of ductile iron castings.U ovom radu je analiziran utjecaj parametara koji su registrirani i mjereni toplinskom analizom na broj nodula/mm2 i nodularnost u odljevcima od nodularnog lijeva. Dobiveni rezultati pokazuju da broj nodula/mm2 i nodularnost rastu s povećanjem temperature eutektičnog pothlađenja (TEP) i grafitnog faktora 1 (GRF 1), te smanjenjem rekalescencije (TR), grafitnog faktora 2 (GRF 2) i vrijednost prve derivacije krivulje hlađenja na solidus temperaturi (d/dt TS). Obrada dobivenih rezultata je provedena višestrukom regresijskom analizom. Na osnovi mjerenih toplinskih parametara, formirani su modeli za procjenu broja nodula/mm2 i nodularnosti. Visoke vrijednosti koeficijenata korelacije između mjerenih i procijenjenih vrijednosti broja nodula/mmm2 (nodularnosti) potvrđuju da postoji čvrsta korelacija između toplinskih parametara taline nodularnog lijeva i mikrostrukturnih značajki odljevaka od nodularnog lijeva

REMOVAL OF Ni(II) FROM AQUEOUS SOLUTION BY LOW-COST ADSORBENTS

The use of low-cost adsorbents has been investigated as a replacement for costly adsorbents and methods of removing nickel ions from aqueous solution. The purpose of this review article is to provide the scattered available information on various aspects of utilization of low-cost adsorbents derived from agricultural waste, industrial by-products and waste material or natural material. To highlight their technical applicability, selected information on initial nickel concentration, pH level, dose required, adsorption capacity, temperature, thermodynamic data, adsorption isotherm, adsorption kinetics is presented. In generall, technical applicability and cost-effectiveness are the key factors in the selection of the most suitable adsorbent to treat aqueous solution contain nickel ions