V. Danciulescu, E. Bucur, M. Petrescu, M. Bratu, A. Cozea, G. Tanase
{"title":"Comparative assessment of air pollutant emissions from brick manufacturing","authors":"V. Danciulescu, E. Bucur, M. Petrescu, M. Bratu, A. Cozea, G. Tanase","doi":"10.21698/rjeec.2020.222","DOIUrl":"https://doi.org/10.21698/rjeec.2020.222","url":null,"abstract":"In this paper, a comparison is made of the level of air pollution between two brick production lines that apply different technologies, one old and one new, and more efficient. The main pollutants emitted in the air from the baking kilns are CO, SO2, NO2, HCl, HF, and dust. The monitoring of emissions was performed with a Testo 350 flue gas analyzer – the automatic method. A Paul Gothe isokinetic sampler was used to take dust, HCl, and HF sampling, and the analysis was performed in the laboratory using gravimetric and spectrophotometric analytical methods. The results of the tests performed showed a reduction in the level of pollution by applying the new and BAT technologies by up to 90% for all monitored pollutants, compared to the pollution produced by old and non-re-technologized line. At the same time, energy consumption is lower per unit of product, which results in a significant decrease in production costs.","PeriodicalId":21370,"journal":{"name":"Romanian Journal of Ecology & Environmental Chemistry","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87172271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Catrina, Lidia Kim, A. Serbanescu, I. Cristea, M. Barbu, I. Nicolescu, G. Vasile
{"title":"Determination of phosphorus in different types of waste using the ICP-MS technique","authors":"G. Catrina, Lidia Kim, A. Serbanescu, I. Cristea, M. Barbu, I. Nicolescu, G. Vasile","doi":"10.21698/rjeec.2020.217","DOIUrl":"https://doi.org/10.21698/rjeec.2020.217","url":null,"abstract":"The research aimed to provide an optimized method for the determination of phosphorous concentration in different types of solid waste using inductive coupled plasma mass spectrometry (ICP-MS) technique. The analyzed waste matrices are: a) vegetable waste (P1), b) ash from the incineration of medical waste (P2) c) sewage sludge (P3) and d) sludge from the meat processing industry (P4). The results obtained by the ICP-MS method were compared with the UV-VIS spectrophotometric method for the determination of total phosphorus. In the case of using the colorimetric method by UV-VIS technique, lower results were obtained compared to the ICP-MS method due to the interferences given by the reagents used to determine the total phosphorus. The interferences given by other elements (metals) were also investigated and the performance parameters were determined such as detection limit, quantification limit, recovery and expandend incertainty using ICP-MS technique.","PeriodicalId":21370,"journal":{"name":"Romanian Journal of Ecology & Environmental Chemistry","volume":"105 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85882571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Negrea, L. A. Diaconu, V. Nicorescu, D. Neidoni, A. Baciu, Claudia Licurici, F. Manea
{"title":"Comparative testing of Ag/Au/Pt graphene electromodified electrodes in electrochemical detection of tetracycline-emerging pollutant","authors":"S. Negrea, L. A. Diaconu, V. Nicorescu, D. Neidoni, A. Baciu, Claudia Licurici, F. Manea","doi":"10.21698/rjeec.2020.219","DOIUrl":"https://doi.org/10.21698/rjeec.2020.219","url":null,"abstract":"This study aimed to obtain new electrochemically modified electrodes with graphene and Au, Pt, Ag particles considering graphite (GP) and glassy carbon (GC) substrate by applying the chronoamperometry technique to develop the detection protocol of tetracycline (TC) considered as an emerging pollutant in water, using cyclic voltammetry (CV) technique. The graphite-based substrate used for Ag/ Au/ Pt electrodeposition led to the electrode compositions on which TC oxidation process was not diffusion-controlled and as consequence, TC detection failed. TC detection protocols were developed for all Ag/Au /Pt electrodeposited GC and GCGP electrodes. Better limits of TC detection was achieved for Ag electrodeposited on GC-GP at the cathodic potential of 0.460 V/SCE.","PeriodicalId":21370,"journal":{"name":"Romanian Journal of Ecology & Environmental Chemistry","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79079435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Graphical and computational methods for determining the stability constants of mono- and polynuclear complexes with a common intersection point of the family of formation curves","authors":"I. Povar, O. Spînu, B. Pintilie","doi":"10.21698/rjeec.2020.210","DOIUrl":"https://doi.org/10.21698/rjeec.2020.210","url":null,"abstract":"Aqueous polynuclear systems have been analyzed, for which the family of formation curves intersects at a common point. The analyzed graphical and computational method for determining the stability constants can be used as initial values within the iterative calculation process. In some cases, the stability constants are calculated using only the coordinates of the common intersection point. The obtained equations could be of special interest when the experimental data can be interpreted in several models. In these cases, given the large volume of experimental data, the calculation is simple and the model can certainly be chosen with high safety. The obtained equations may also be applied for critical evaluation of tabular data if the coordinates of the intersection point are known. A series of real polynuclear systems have been analyzed and useful conclusions have been made.","PeriodicalId":21370,"journal":{"name":"Romanian Journal of Ecology & Environmental Chemistry","volume":"125 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74136022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Cavitation action on the cocci bacteria","authors":"I. Koval, A. Hajiali","doi":"10.21698/rjeec.2020.206","DOIUrl":"https://doi.org/10.21698/rjeec.2020.206","url":null,"abstract":"Features of growth of microorganisms on a nutrient medium and their microscopic researches were studied. Cavitation treatment (22 kHz, 91 W, 1.65 W/сm3) of water with the simultaneous action of bubbled inert gases (argon and helium) on the viability of microbial cells (Diplococcus and Sarcina) are presented. The highest water disinfection was obtained for water samples with Sarcina lutea cells for both used gases under cavitation conditions. Both investigated types of cocci bacteria were destroyed faster under Ar/US-action after comparison of the effectiveness of the gas nature action on the water disinfection.","PeriodicalId":21370,"journal":{"name":"Romanian Journal of Ecology & Environmental Chemistry","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88902535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexandra-Elisabeta Stamate, R. Zăvoianu, O. Pavel, A. Cruceanu, M. Corobea, M. Osiac, N. Cioateră
{"title":"LDH-GO composites as catalysts for the oxidative removal of indigo carmine\u0000dye from wastewater","authors":"Alexandra-Elisabeta Stamate, R. Zăvoianu, O. Pavel, A. Cruceanu, M. Corobea, M. Osiac, N. Cioateră","doi":"10.21698/rjeec.2020.201","DOIUrl":"https://doi.org/10.21698/rjeec.2020.201","url":null,"abstract":"Herein, we present the results of our researches focused on obtaining composites with enhanced affinity for indigo carmine (IC) by combining two different 2D materials e.g. graphene oxide (GO) and a Cerium modified layered double hydroxide (LDH), which could act as catalysts for the oxidative removal of IC, both under ultrasonic irradiation and under conventional stirring, using H2O2 as oxidation agent. Three Mg3Al0.75Ce0.25 LDH-GO composites bearing different concentrations of GO in the range of 5-15 wt.% abbreviated as HT3Ce-xGO where x stands for the concentration of GO (x=5,10,15% wt. GO) have been prepared and characterized by XRD, SEM, Raman and DRIFT spectroscopy. The XRD patterns of HT3Ce-xGO solids have revealed the formation of nanocomposites with fine particles of CeO2 (Scherrer dimensions around 3 nm) embedded in the 2D layered structure of LDH-GO. CeO2 phase was favored by the increase in GO content for all investigated composites. The size decrease of the solid particles with the increase of GO content was proved both by SEM and DRIFT analyses. Raman spectra proved the incorporation of GO in all composites. The results of the catalytic tests showed, without any doubt the activation effect of the ultrasonic irradiation which allowed doubling the dye removal percentage (DR%) in the first 30 minutes of reaction time. For the most active catalyst, HT3Ce-15GO, the COD after 30 minutes reaction time under ultrasonic irradiation was 221 mgO2/L, while TOC was 93 mgC/L marking a decay of 61.6% for COD and 46.2% for TOC.","PeriodicalId":21370,"journal":{"name":"Romanian Journal of Ecology & Environmental Chemistry","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75443082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}