11 research outputs found
TREATMENT OF WASTEWATER FROM SWINE AND POULTRY SLAUGHTERHOUSES
The meat processing industry produces large volumes of slaughterhouse wastewater (SWW). For this reason, water and wastewater treatment has become crucial for the continuing development of the society. The present study reveals the water pollution degree from poultry and the swine slaughterhouses from Bacau (Romania). The possibility of reducing the quantity of pollutants by the active sludge treatment method is also presented. The efficiency of this treatment processes was evaluated through the following parameters: biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solids (TSS), turbidity, both before and after the active sludge treatment
TREATMENT OF WASTEWATER FROM SWINE AND POULTRY SLAUGHTERHOUSES
The meat processing industry produces large volumes of slaughterhouse wastewater (SWW). For this reason, water and wastewater treatment has become crucial for the continuing development of the society. The present study reveals the water pollution degree from poultry and the swine slaughterhouses from Bacau (Romania). The possibility of reducing the quantity of pollutants by the active sludge treatment method is also presented. The efficiency of this treatment processes was evaluated through the following parameters: biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solids (TSS), turbidity, both before and after the active sludge treatment
A GREEN APPROACH FOR THE SELECTIVE REDUCTION OF AROMATIC CARBONYL COMPOUNDS USING RANEY Ni-Al ALLOY
Given the significant environmental risk associated with the use of organic solvents and catalysts in the classic reduction reaction catalysts, we are interested in adapting the reaction medium and in developing an eco-friendly methodology for the synthesis of corresponding alcohols in reasonably yields. In this study, the reduction of some aromatic carbonyl compounds with Ni-Al alloy in aqueous alkaline medium was carried out in two versions: with 20 wt% aq NaOH and with 1 wt% aq NaOH without organic solvent. The structures of the reaction products are rigorously proven by gas chromatography-mass spectrometry (GC-MS). There was observed an increase of the reduction reaction rate when we used 1 wt% aq NaOH without addition of organic solvent. For a good part of the studied substrates high conversion and selectivity were achieved by employing mild reaction conditions, minimal environmental pollution and simple work up procedure, foreshadowing yields above 90 % and representing candidates for convenient preparative applications
ASSESSMENT OF GROUNDWATER AND SURFACE WATER CONTAMINATION BY LANDFILL LEACHATE: A CASE STUDY IN NEAMT COUNTY, ROMANIA
International audienceThe aim of this study was to determine the actual impact of the uncontrolled landfill site in Roman town, Romania on the water resource quality. The surface water and groundwater samples were collected quarterly in two time periods: January 2012 - June 2013, when the landfill was operational and July 2013 - December 2014, after the landfill was closed. The parameters analyzed in this study include: pH, biological oxygen demand (BOD5), chemical oxygen demand (COD), NH4+ Cl-, NO2-, NO3-, SO42-, heavy metals (Cd, Pb, Hg, Cr, Cu, Ni). In the case of surface water, for both investigated periods, the only parameter that exceeds the maximum allowable limit is the chemical oxygen demand with a maximum value of 235 mg O-2/L. The high values of the COD indicator may be attributed to the contamination of the surface water with persistent organic pollutants from landfill leachate. The results recorded in the case of groundwater show that the maximum allowable limits for parameters BOD5, COD, NH4+, Cl-, NO2- are exceeded for both investigated periods. All the mean concentrations of heavy metals for the two periods investigated showed values that exceed the maximum allowable limits, except Pb (3.5-6.67 mu g/L) and Hg (n.d.) which were below the limits. Analyzing the results, it can be noticed that the landfill affected the groundwater and the surface water quality, both during the period when it was in use, and after its closure. It represents a risk to human health due to the contaminants that seep into the groundwater, given the proximity of the landfill to the inhabited area (about 200 m). Since this landfill is a source of contamination even after being closed, it is necessary to neutralize it and to monitor the surface and groundwater quality indicators periodically
PHYSICOCHEMICAL CHARACTERIZATION AND ACCEPTABILITY OF SOME ARTISANAL MINT LIQUEURS
The medicinal herb Mentha piperita L. has been used for hundreds of years for its remarkable medicinal properties. Due to its composition rich in essential oil, terpenes, flavonoids etc., the peppermint is commonly used in various fields for obtaining cosmetics, medicines, and also in the food industry. The aim of the present study consisted in developing accessible recipes for preparation of artisanal dessert mint liqueurs by different extraction variants and determining their physicochemical and sensory analyses. Four types of mint liqueurs were prepared by maceration of peppermint leaves in alcohol, varying the extraction parameters: time, temperature or by changing the order of ingredients addition. For the obtained artisanal liqueurs samples the following physicochemical characteristics were determined: dry extract, alcoholic strength, soluble solids, total acidity, fixed acidity, volatile acidity, density, conductivity and refractive index. The samples prepared were organoleptically analyzed by a multi-sensory approach (appearance and clarity, color, odor and aroma, taste) using the scoring method and the results revealed that the artisanal liqueurs obtained are well accepted by the consumers
Biosorption Potential of Microbial and Residual Biomass of Saccharomyces pastorianus Immobilized in Calcium Alginate Matrix for Pharmaceuticals Removal from Aqueous Solutions
Two types of biosorbents, based on Saccharomyces pastorianus immobilized in calcium alginate, were studied for the removal of pharmaceuticals from aqueous solutions. Synthetized biocomposite materials were characterized chemically and morphologically, both before and after simulated biosorption. Ethacridine lactate (EL) was chosen as a target molecule. The process performance was interpreted as a function of initial solution pH, biosorbent dose, and initial pharmaceutical concentration. The results exhibited that the removal efficiencies were superior to 90% for both biosorbents, at the initial pH value of 4.0 and biosorbent dose of 2 g/L for all EL initial concentrations tested. Freundlich, Temkin, Hill, Redlich-Peterson, Sips, and Toth isotherms were used to describe the experimental results. The kinetic data were analyzed using kinetic models, such as pseudo-first order, pseudo-second order, Elovich, and Avrami, to determine the kinetic parameters and describe the transport mechanisms of EL from aqueous solution onto biosorbents. Among the tested equations, the best fit is ensured by the pseudo-second-order kinetics model for both biosorbents, with the correlation coefficient having values higher than 0.996. The many potential advantages and good biosorptive capacity of Saccharomyces pastorianus biomass immobilized in calcium alginate recommend these types of biocomposite materials for the removal of pharmaceuticals from aqueous solutions
Investigation into Biosorption of Pharmaceuticals from Aqueous Solutions by Biocomposite Material Based on Microbial Biomass and Natural Polymer: Process Variables Optimization and Kinetic Studies
International audienceBiosorbtive removal of the antibacterial drug, ethacridine lactate (EL), from aqueous solutions was investigated using as biosorbent Saccharomyces pastorianus residual biomass immobilized in calcium alginate. The aim of this work was to optimize the biosorption process and to evaluate the biosorption capacity in the batch system. Response surface methodology, based on a Box-Behnken design, was used to optimize the EL biosorption parameters. Two response functions (removal efficiency and biosorption capacity) were maximized dependent on three factors: initial concentration of EL solution, contact time, and agitation speed. The highest values for the studied functions (89.49%, 26.04 mg/g) were obtained in the following operational conditions: EL initial concentration: 59.73 mg/L; contact time: 94.26 min; agitation speed: 297.57 rpm. A number of nonlinear kinetic models, including pseudo-first-order, pseudo-second-order, Elovich, and Avrami, were utilized to validate the biosorption kinetic behavior of EL in the optimized conditions. The kinetic data fitted the pseudo-first-order and Avrami models. The experimental results demonstrated that the optimized parameters (especially the agitation speed) significantly affect biosorption and should be considered important in such studies
Application of Saccharomyces cerevisiae/Calcium Alginate Composite Beads for Cephalexin Antibiotic Biosorption from Aqueous Solutions
Cephalexin (CPX) is recognized as a water pollutant, and it has been listed in a number of countries with a risk factor greater than one. Herein, the present work focused on the synthesis, characterization and biosorption capacity evaluation of Saccharomyces cerevisiae immobilized in calcium alginate as a biosorbent to remove CPX from aqueous solutions. Biosorbent was characterized by SEM and FTIR techniques. Batch biosorption experiments were conducted in order to evaluate the effect of the initial pH, biosorbent dose and CPX initial concentration. The removal efficiency, in considered optimal conditions (pH = 4, CPX initial concentration = 30 mg/L, biosorbent dose = 1 g/L) was 86.23%. CPX biosorption was found to follow the pseudo–second-order kinetics. The equilibrium biosorption data were a good fit for the Langmuir model with correlation coefficient of 0.9814 and maximum biosorption capacity was 94.34 mg/g. This study showed that the synthesized biosorbent by immobilization technique is a low-cost one, easy to obtain and handle, eco-friendly, with high feasibility to remove CPX antibiotic from aqueous solution. The findings of this study indicate that the biosorbents based on microorganisms immobilized on natural polymers have the potential to be applied in the treatment of wastewater
Encapsulation of <i>Saccharomyces pastorianus</i> Residual Biomass in Calcium Alginate Matrix with Insights in Ethacridine Lactate Biosorption
Pharmaceuticals are recognized as emerging water microcontaminants that have been reported in several aquatic environments worldwide; therefore, the elimination of these pollutants is a global challenge. This study aimed to develop a biosorbent based on Saccharomyces pastorianus residual biomass encapsulated in a calcium alginate matrix and to evaluate its biosorption performance to remove Ethacridine Lactate (EL) from aqueous solutions. Firstly, the synthesis and characterization of biosorbent has been carried out. Then, the impact of main parameters on biosorption process were investigated by batch experiments. Finally, the kinetics behavior and equilibrium isotherms were evaluated. The resulted beads have an irregular and elongated shape with about 1.89 mm ± 0.13 mm in size with a homogeneous structure. The best removal efficiency for EL of over 85% was obtained at acidic pH 2 and 25 °C for 50 mg/L initial concentration and 2 g/L biosorbent dose. The pseudo-second-order and intraparticle diffusion kinetics describe the biosorption process. The maximum calculated biosorption capacity was 21.39 mg/g similar to that recorded experimentally. The equilibrium biosorption data were a good fit for Freundlich and Dubinin–Radushkevich isotherms. Our findings reveal that the low cost and eco-friendly obtained biosorbent can be easily synthesized and suitable to remove Ethacridine Lactate from water matrices
Biosorptive Removal of Ethacridine Lactate from Aqueous Solutions by <i>Saccharomyces pastorianus</i> Residual Biomass/Calcium Alginate Composite Beads: Fixed-Bed Column Study
In this study, ethacridine lactate removal from aqueous solution using a biosorbent material based on residual microbial biomass and natural polymers in fixed-bed continuous column was investigated. Composite beads of Saccharomyces pastorianus residual biomass and calcium alginate were obtained by immobilization technique. The prepared biosorbent was characterized by Fourier transformed infrared spectroscopy, scanning electron microscopy, and analysis of point of zero charge value. Then, laboratory-scale experiments by fixed-bed column biosorption were conducted in continuous system. To this purpose, the column bed high (5 cm; 7.5 cm), initial pollutant concentration (20 mg/L; 40 mg/L), and solution flow through the column (0.6 mL/min; 1.5 mL/min) were considered the main parameters. Recorded breakthrough curves suggest that lower flow rates, greater bed heights, and a lower concentration of ethacridine lactate led to an increased biosorption of the target compound. The biosorption dynamic was investigated by nonlinear regression analysis using the Adams–Bohart, Yoon–Nelson, Clark, and Yan mathematical models. Conclusively, our research highlights, firstly, that the obtained biosorbent material has the required properties for retaining the ethacridine lactate from aqueous solution in continuous system. Secondly, it emphasizes that the modeling approach reveals an acceptable fitting with the experimental data for the Yoon–Nelson, Clark, and Yan models