2021, Issue 67(71), Fasc. 3 (September)

Contents

pages 1- 8   Download

Evaluation of the toxicity of Some Heavy Metals on Yeasts Using a Diffusimetric Method of Analysis

MARIANA DIACONU, “Gheorghe Asachi” Technical University Of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection
IRINA VOLF, “Gheorghe Asachi” Technical University Of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection
ELENA RALUCA BULAI, “Ștefan Cel Mare” University of Suceava, Department of Health and Human Development
CĂTĂLIN DUMITREL BĂLAN, “Gheorghe Asachi” Technical University Of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, cbalan@tuiasi.ro

pages 9 - 19   Download
Abstract
This study reports the influence of cadmium, chromium and nickel ions on yeast strains using the diffusimetric method, on agar plate culture media. The tested yeast species show a different sensitivity depending on the metal ion in their culture medium and its concentration. S. cerevisiae proved to be the least sensitive to the presence of metal ions. Chromium ions have been shown to be the most toxic to the three yeast strains (R. rubra, T. cutaneum and S. cerevisiae).
Keywords: heavy metal; diffusimetric methods; yeast; inhibition; toxicity.

Impact of Sugar Beet Manufacturing Activity within S.C. Agrana Romania S.A. – Roman, Neamț County on the Environment

ALINA AGAFIȚEI, “Gheorghe Asachi” Technical University of Iași, Faculty of Hydrotechnics, Geodesy and Environmental Engineering, alinaagafitei@yahoo.com
VASILE LUCIAN PAVEL, “Gheorghe Asachi” Technical University of Iași, Faculty of Hydrotechnics, Geodesy and Environmental Engineering
PAULA COJOCARU, “Gheorghe Asachi” Technical University of Iași, Faculty of Hydrotechnics, Geodesy and Environmental Engineering

pages 21-27   Download
Abstract
The industrial activities have a major impact on all environmental factors, by affecting the quality of air, water, soil, generation of different waste types, and through use of natural resources and energy. Sugar beet production has gained momentum and reached approx. 30% of today’s world beet sugar production. Also called “white gold”, sugar came to be taxed with astronomical sums due to growing demand for it. The present paper analysis the impact of beet sugar manufacturing activity on the main environmental factors, starting with technological wastewater, domestic water, purified and directed through pipes in the natural emissary, studying the concentrations of nitrites, nitrates, iron and nickel ions, in three different analysis period, calculating the retention yields at the station for the most important chemical indicators. We studied emissions into atmosphere from technological sources, from micro-power-plants, checking the flue gas circuits, by measurements at the flue gas dispersion basket, by checking the dust entrainments. We also identified, one by one, the local pouring areas inside, we measured the pollutants concentrations in soil, and previous and present damage of the soil. Following the findings, we analyze the degree of pollution on each environmental factor, establishing conclusions and recommendations.
Keywords: diffusion; environmental factors; pollution; sugar industry; waste.

Obtaining Pet-Clay Adsorbent Materials and their Use for the Removal of Pb(II) Ions from Aqueous Media

CODRUŢ-ŞTEFAN CIOBANU, “Gheorghe Asachi” Technical University of Iaşi, “Cristofor Simionescu” Faculty of Chemical Engineering and Environment Protection
DUMITRU BULGARIU, “Al. I. Cuza” University of Iaşi, Faculty of Geography and Geology; Romanian Academy, Filial of Iaşi, Branch of Geography
BIANCA AZAMFIRE, “Gheorghe Asachi” Technical University of Iaşi, “Cristofor Simionescu” Faculty of Chemical Engineering and Environment Protection
LAURA BULGARIU, “Gheorghe Asachi” Technical University of Iaşi, “Cristofor Simionescu” Faculty of Chemical Engineering and Environment Protection, lbulg@ch.tuiasi.ro

pages 29 - 38   Download
Abstract
The performance of PET flakes as adsorbents for the removal of harmful pollutants from aqueous solution is quite low and, therefore its use in the decontamination processes of the environment is insignificant. However, increasing quantities of PET waste discharged into the environment require opportunities for valorization. In this study, PET flakes were mixed with clay mineral, and melted under different experimental conditions (temperature, melting time, mixing ratio, addition of phenol, etc.), to obtain new materials with adsorptive potential. The methodology used for the preparation of these materials was detailed discussed, and the experimental conditions were optimized. Also, the adsorptive potential of each obtained material was tested for the removal of Pb(II) ions from aqueous solution. The experimental results have shown that the mixing of PET waste with clay mineral (mixing ration 1: 2) and the melting at 350°C for 25 min, allows to obtain a material (PET-clay(1:2)-350°C-25 min) with an adsorption capacity for Pb(II) ions (18.59 mg/g) comparable to that of raw clay mineral. Therefore, PET-clay(1:2)-350°C-25 min material has the potential to be used as adsorbent in environmental decontamination processes.
Keywords: absorbent materials; PET flakes; clay mineral; Pb(II) ions; environmental decontamination.

Analysis of the Optimal Bridge Piers Number for Reducing Backwater Levels

ANCA DĂNILĂ, “Gheorghe Asachi” Technical University of Iași, Faculty of Hydrotechnics, Geodesy and Environmental Engineering, anca.danila@tuiasi.ro
IOAN-CORNELIU MARȚINCU, “Gheorghe Asachi” Technical University of Iași, Faculty of Hydrotechnics, Geodesy and Environmental Engineering
CLARISA PARASCHIVESCU, “Gheorghe Asachi” Technical University of Iași, Faculty of Hydrotechnics, Geodesy and Environmental Engineering
RALUCA GIURMA-HANDLEY, “Gheorghe Asachi” Technical University of Iași, Faculty of Hydrotechnics, Geodesy and Environmental Engineering
TOMI-ALEXĂNDREL HRĂNICIUC, “Gheorghe Asachi” Technical University of Iași, Faculty of Hydrotechnics, Geodesy and Environmental Engineering

pages 39 - 49   Download
Abstract
Like much of the Vienne Valley, the area of Bouchard Island has a significant wealth in terms of environments and species. In the study area, 86 protected species are recorded, half of which are birds. The major areas of issue are located on the crossing of Vienne, along rivers and ponds and in the North sector of Bouchard Island. The presence of the Margaritifera auricularia, or Spengler's freshwater mussel is a major issue of the site because of its status as an invertebrate being one of the most threatened on the planet and its presence on the course of Vienne. In order to quantify the damping of the backwater generated by the future crossing of the Vienne, we integrated into the hydraulic modelling software (InfoWorks ICM) the 2D model of the river and using 2 solutions (3 and 4 piers) to simulate the current flow conditions generated by the future bridge for each of the two floods studied as a function the width of the piles. The hydraulic study of the Vienna crossing will be based on a two-dimensional (2D) modelling of flows because unlike conventional one-dimensional modelling, two-dimensional modelling allows to know precisely the speed in any point of the project area, to size the crossing structure and the piers and to assess more detailed the local impact of the project, in particular on the distribution of speeds in major beds.
Keywords: river; floods; discharge; hydrodynamic model; hydraulic model.

Unconventional Microwave Heat Treatment Technique for Producing Cellular Glass by Sintering/Foaming the Recycled Glass Waste with Silicon Carbide and Coal Fly Ash

LUCIAN PAUNESCU, Daily Sourcing & Research SRL Bucharest, Romania, lucianpaunescu16@gmail.com
SORIN MIRCEA AXINTE, Daily Sourcing & Research SRL Bucharest, Romania; University “Politehnica” of Bucharest, Department of Applied Chemistry and Materials Science
FELICIA COSMULESCU, Cosfel Actual SRL Bucharest, Romania

pages 51 - 62   Download
Abstract
The paper presents experimental results obtained in the microwave field manufacturing of an ecological cellular glass-ceramic using clear flat glass waste and coal fly ash as raw materials and silicon carbide as a foaming agent. The experiments have shown that under the influence of microwave irradiation, foamed products have a good microstructural homogeneity, although it is known from the literature that the flat glass is not suitable for a foaming with uniform pore distribution. The optimal sample of cellular glass-ceramic sintered at 977°C had thermal insulation properties (apparent density of 0.42 g/cm3 and thermal conductivity of 0.085 W/m·K) as well as high compressive strength of 2.4 MPa, being suitable for using as a thermal insulation building material.
Keywords: cellular glass-ceramic; flat glass waste; microwave heating; silicon carbide; microstructural homogeneity.

Residual Biomass of Lactobacillus Immobilized in Alginate for Orange 16 Dye Retention from Aqueous Medium

DANIELA ȘUTEU, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, danasuteu67@yahoo.com
ALEXANDRA CRISTINA BLAGA, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection
CARMEN ZAHARIA, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection
IOANA LUIZA HORCIU, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection

pages 63 - 72   Download
Abstract
The biosorption abilities of residual Lactobacillus biomass immobilized in alginate towards reactive organic dyes have been studied. Batch biosorption studies were carried out for the retention of reactive Orange 16 dye. Studies have shown that the biosorption process is influenced by the size and amount of biosorbent, dye solution pH, initial dye concentration, temperature and phases contact time. Preliminary results have suggested that the studied residual biomass immobilized in sodium alginate may be an effective biosorbent for retaining dyes from dye-containing wastewater.
Keywords: biosorption; immobilized biomass; reactive Orange 16 dye; wastewater