Electrochemical impedance spectroscopy characterization of surfactant sensor with multi walled carbon nanotubes (MWCNT)

Konstruiran je cjenovno povoljan čvrsti anionski tenzidni senzor visoke osjetljivosti uz dodatak ionskog para, višestjenčanih ugljikovih nanocjevčica (eng. Multi walled carbon nanotubes, MWCNT) i jeftine grafitne mine iz olovke kao nosioca senzorskog sloja. Cilj rada bio je ispitati tenzidne senzore s različitim masenim udjelom MWCNT elektrokemijskom impedancijskom spektroskopijom, a potom modelirati eksperimentalne podatke prema pretpostavljenom modelu strujnog kruga. Eksperimentalni rezultati su pokazali da se povećanjem udjela MWCNT u ispitivanim senzorima smanjuje impedancija odnosno otpor prijenosu naboja te da promjena koncentracije anionskog tenzida (natrijevog dodecilsulfata) ne utječe na izgled impedancijskog spektra. Impedancijski spektri ispitivanih tenzidnih senzora modelirani su pomoću ZView računalnog programa. Pretpostavljeni model strujnog kruga je uključivao otpor otopine ($R_{1}$), otpor prijenosu naboja ($R_{2}$), kapacitet dvosloja na međupovršini MWCNT/otopina ($Q_{2}$), te Warburgov element (W) koji se odnosio na procese difuzije. Utvrđeno je da pretpostavljeni model strujnog kruga dobro opisuje ispitivani sustav budući da nisu uočena veća odstupanja eksperimentalno dobivenih i matematički modeliranih impedancijskih spektara.Low cost solid-contact anionic surfactant sensor with high sensitivity was constructed, with the addition of ion pair, multi walled carbon nanotubes (MWCNT) and cheap graphite pencil from the pen as the sensor layer carrier. The aim of this study was to investigate surfactant sensors with different mass fraction of MWCNT with electrochemical impedance spectroscopy and then model the experimental data according to the assumed model of the electrical circuit. Experimental results have shown that by increasing the MWCNT fraction in the tested sensors, the impedance or charge transfer resistance is reduced and that the change of the concentration of anionic surfactant (sodium dodecyl sulphate) didn`t affect the appearance of the impedance spectrum. Impedance spectra of the investigated surfactant sensors were modeled using the ZView computer program. The assumed model of electrical circuit included resistance of the solution ($R_{1}$), charge transfer resistance ($R_{2}$), double layer capacitance at the MWCNT / solution interface ($Q_{2}$), and Warburg element (W) related to the diffusion processes. It was found that the assumed model of electrical circuit describes well the investigated system since no greater deviations of the experimentally obtained and mathematically modeled impedance spectra were observed

Environmental pollution

Problem oneĉišćenja prirode i okoliša trajna je pojava tijekom povijesti našeg planeta, ali je izrazito pojaĉan posljednjih nekoliko desetljeća. Oneĉišćenje prirode i okoliša svako je unošenje štetnih tvari i energije koje narušava prirodni sklad vode, zraka i tla. Oneĉišćenje vode predstavlja kvantitativno i kvalitativno odstupanje od normalnog i prirodnog, kemijskog, biološkog i fiziĉkog sastava i kakvoće. Glavni oneĉišćivaći su otpadne vode, koje ovisno o mjestu nastanka mogu biti komunalne, kućanske, oborinske, industrijske, procesne, itd. Oneĉišćenje zraka moţe biti lokalno i globalno. Lokalno oneĉišćenje je vezano uz gradove i industrijska podruĉja dok je globalno vezano za oneĉišćenje zraka u cijelosti. Glavni oneĉišćivaći zraka su razni plinovi koji nastaju kemijskim procesima te erupcije vulkana. Oneĉišćenje tla takoĊer moţe biti lokalno i globalno, lokalno je vezano uz velike gradove i veća industrijska podruĉja, a globalno je vezano uz prijenos štetnih tvari oborinama, vodotocima i podzemnim vodama. Glavni oneĉišćivaĉi tla su poljoprivredna proizvodnja i smeće.The environment and nature pollution problem is a permanent phenomenom throught the history of our planet and it is markedly enhanced in the last few decades. Every kind of harmful substances and energy that disrupts the natural balance of water, air and soil pollutes nature and the environment. Water pollution presents quantitative and qualitative deviation from the normal and natural, chemical, biological and pshysical composition and quality. The main polluters are waste waters, which depending on their origin can be communal, household, industrial and processed, stormwater, etc. Air pollution can be local and global. Local pollution is related to cities and industrial areas, while global pollution is related to air pollution altogether. The main air polluters are various gasses formed by chemical processes and volcanic eruptions. Soil pollution can also be local and global, local is related to big cities and major industrial areas, while global is related to the transmission of harmful substances such as: precipitation, streams and groundwaters. The main polluters are agricultural production and garbage

Water for all : Proceedings of the 7th international scientific and professional conference Water for all

The 7th International Scientific and Professional Conference Water for all is organized to honour the World Water Day by the Josip Juraj Strossmayer University of Osijek, European Hygienic Engineering & Design Group (EHEDG), Danube Parks, Croatian Food Agency, Croatian Water, Faculty of Food Technology Osijek, Faculty of Agriculture in Osijek, Faculty of Civil Engineering Osijek, Josip Juraj Strossmayer University of Osijek Department of Biology, Josip Juraj Strossmayer University of Osijek Department of Chemistry, Nature Park “Kopački rit”, Osijek- Baranja County, Public Health Institute of the Osijek- Baranja County and „Vodovod-Osijek“ -water supply company in Osijek. The topic of World Water Day 2017 was "Wastewater" emphasizing the importance and influence of wastewater treatments on global environment. The international scientific and professional conference Water for all is a gathering of scientists and experts in the field of water management, including chemists, biologists, civil and agriculture engineers, with a goal to remind people about the significance of fresh water and to promote an interdisciplinary approach and sustainability for fresh water resource management. The Conference has been held since 2011. About 300 scientists and engineers submitted 95 abstracts to the 7th International Scientific and Professional Conference Water for all, out of which 33 was presented orally and 62 as posters. 47 full papers were accepted by the Scientific Committee. 38 full papers became the part of the this Proceedings while 9 papers were accepted for publication in Croatian Journal of Food Science and Technology and Electronic Journal of the Faculty of Civil Engineering Osijek - e-GFOS

Environmental pollution

Problem oneĉišćenja prirode i okoliša trajna je pojava tijekom povijesti našeg planeta, ali je izrazito pojaĉan posljednjih nekoliko desetljeća. Oneĉišćenje prirode i okoliša svako je unošenje štetnih tvari i energije koje narušava prirodni sklad vode, zraka i tla. Oneĉišćenje vode predstavlja kvantitativno i kvalitativno odstupanje od normalnog i prirodnog, kemijskog, biološkog i fiziĉkog sastava i kakvoće. Glavni oneĉišćivaći su otpadne vode, koje ovisno o mjestu nastanka mogu biti komunalne, kućanske, oborinske, industrijske, procesne, itd. Oneĉišćenje zraka moţe biti lokalno i globalno. Lokalno oneĉišćenje je vezano uz gradove i industrijska podruĉja dok je globalno vezano za oneĉišćenje zraka u cijelosti. Glavni oneĉišćivaći zraka su razni plinovi koji nastaju kemijskim procesima te erupcije vulkana. Oneĉišćenje tla takoĊer moţe biti lokalno i globalno, lokalno je vezano uz velike gradove i veća industrijska podruĉja, a globalno je vezano uz prijenos štetnih tvari oborinama, vodotocima i podzemnim vodama. Glavni oneĉišćivaĉi tla su poljoprivredna proizvodnja i smeće.The environment and nature pollution problem is a permanent phenomenom throught the history of our planet and it is markedly enhanced in the last few decades. Every kind of harmful substances and energy that disrupts the natural balance of water, air and soil pollutes nature and the environment. Water pollution presents quantitative and qualitative deviation from the normal and natural, chemical, biological and pshysical composition and quality. The main polluters are waste waters, which depending on their origin can be communal, household, industrial and processed, stormwater, etc. Air pollution can be local and global. Local pollution is related to cities and industrial areas, while global pollution is related to air pollution altogether. The main air polluters are various gasses formed by chemical processes and volcanic eruptions. Soil pollution can also be local and global, local is related to big cities and major industrial areas, while global is related to the transmission of harmful substances such as: precipitation, streams and groundwaters. The main polluters are agricultural production and garbage

Electrochemical impedance spectroscopy characterization of surfactant sensor with multi walled carbon nanotubes (MWCNT)

Konstruiran je cjenovno povoljan čvrsti anionski tenzidni senzor visoke osjetljivosti uz dodatak ionskog para, višestjenčanih ugljikovih nanocjevčica (eng. Multi walled carbon nanotubes, MWCNT) i jeftine grafitne mine iz olovke kao nosioca senzorskog sloja. Cilj rada bio je ispitati tenzidne senzore s različitim masenim udjelom MWCNT elektrokemijskom impedancijskom spektroskopijom, a potom modelirati eksperimentalne podatke prema pretpostavljenom modelu strujnog kruga. Eksperimentalni rezultati su pokazali da se povećanjem udjela MWCNT u ispitivanim senzorima smanjuje impedancija odnosno otpor prijenosu naboja te da promjena koncentracije anionskog tenzida (natrijevog dodecilsulfata) ne utječe na izgled impedancijskog spektra. Impedancijski spektri ispitivanih tenzidnih senzora modelirani su pomoću ZView računalnog programa. Pretpostavljeni model strujnog kruga je uključivao otpor otopine ($R_{1}$), otpor prijenosu naboja ($R_{2}$), kapacitet dvosloja na međupovršini MWCNT/otopina ($Q_{2}$), te Warburgov element (W) koji se odnosio na procese difuzije. Utvrđeno je da pretpostavljeni model strujnog kruga dobro opisuje ispitivani sustav budući da nisu uočena veća odstupanja eksperimentalno dobivenih i matematički modeliranih impedancijskih spektara.Low cost solid-contact anionic surfactant sensor with high sensitivity was constructed, with the addition of ion pair, multi walled carbon nanotubes (MWCNT) and cheap graphite pencil from the pen as the sensor layer carrier. The aim of this study was to investigate surfactant sensors with different mass fraction of MWCNT with electrochemical impedance spectroscopy and then model the experimental data according to the assumed model of the electrical circuit. Experimental results have shown that by increasing the MWCNT fraction in the tested sensors, the impedance or charge transfer resistance is reduced and that the change of the concentration of anionic surfactant (sodium dodecyl sulphate) didn`t affect the appearance of the impedance spectrum. Impedance spectra of the investigated surfactant sensors were modeled using the ZView computer program. The assumed model of electrical circuit included resistance of the solution ($R_{1}$), charge transfer resistance ($R_{2}$), double layer capacitance at the MWCNT / solution interface ($Q_{2}$), and Warburg element (W) related to the diffusion processes. It was found that the assumed model of electrical circuit describes well the investigated system since no greater deviations of the experimentally obtained and mathematically modeled impedance spectra were observed