Liter Of Solution Research Articles

DEVELOPMENT OF THE POWER SUPPLY AND CONTROL SYSTEM FOR THE HEMODIALYSIS MACHINE

The article describes new approaches to creating an autonomous compact system with automatic control for hemodialysis. It is proposed to organize a closed circuit for cleaning the dialysis solution using an electrolytic regenerator as a function of the concentration of urea in it. The functional diagram of the created system is presented and described. To power the regenerator, ensure thermal stabilization of the solution, and power auxiliary electronic and electrical equipment, a multi-channel power supply and control system for the hemodialysis machine based on high-frequency magnetic amplifiers has been developed and researched. The advantages of power switches based on high-frequency magnetic amplifiers in comparison with transistor switches, including in the construction of controlled power sources, are given. The principle of operation of the voltage regulator on high-frequency magnetic amplifiers is described. Theoretical and experimental oscillograms are given. Photographs of the experimental unit as well as an industrial sample of the multi-channel power supply and control system of the hemodialysis machine are provided. Their main technical characteristics are given. Conclusions to the conducted work are formulated. Carrying out the regeneration of the dialysis solution significantly reduces its costs – 2 liters of solution, which is suitable for use for 6 months, is enough for the operation of the device. Existing hemodialysis machines are a stationary open system using a single-use dialysis solution at a rate of up to 35 l/h, which ties the machine to stationary clinical conditions. Introducing feedback on the concentration of urea in the dialysis solution allows you to automate the blood purification procedure, as well as automatically complete hemodialysis at the necessary time, and also eliminates the dependence of the device on the conditions of the hospital.

Production of tomato cultivated in different nutritive solutions

The objective this paper is determine the highest performance of fresh mass and number of fruits in tomato crops using different nutrient solution. An absolute hybrid with a semi-determined growth was used. It was grown in a protected environment using a fertigated substrate inside plastic bags containing ten liters of solution. The experiment was completely randomized with four levels of fertilization and five replications. Two experiments were carried out in two cultivation cycles (spring 2018 and autumn 2019) by performing an analysis of variance and Scott & Knott test and estimating the parameters of nonlinear logistic model and its critical points for both variables in each treatment. The mean fruit mass per plant was 3.70 kg for the spring experiment and 3.80 kg for the autumn experiment. The mean number of fruits per plant was 10.50 and 10.70 fruits for spring and autumn, respectively. There are significant differences between the treatments KO46, KO45 and KO56 compared to KO69 for fruit mass in the autumn experiment. For the other variables and cultivation cycles, the treatments did not show statistical differences. The logistic growth model fitted the weight and number of tomato fruits according to days after transplanting the seedlings and evidenced production cycle data, highlighting the main differences between the nutrient solutions. The nutritional solutions KO46, KO45 and KO56 are recommended for growing Gaúcho tomatoes in substrate. The nutrient solution KO56 has the best performance because it has a higher K availability, meets the balance of loads and antagonism between nutrients, provides equal response of means mass and number of fruits, and has a lower N:K ratio and balance of K over Ca and Mg, thus favoring fruit production, precocity, and development.

Atrazine reclamation from an aqueous environment using a ruthenium-based metal-organic framework

The current research describes the synthesis, characterization, and application of a newly developed metal organic framework grounded on ruthenium (Ru-MOF) for the elimination of hazardous chemicals atrazine (AZ) from water. The zeta potential, N2 adsorption/desorption, SEM, TEM, XPS, and FTIR Spectroscopy were used to analyze the Ru-MOF. Ru-MOF has a high surface area of 1058.62 m2.g−1 and micropores with a pore volume of 0.74 cm3.g−1 were produced by the characterization analyses. Additionally, it was discovered that atrazine adsorption produced good results at pH 4 and an adsorbent mass of 0.8 g per liter of solution. The greatest successful fit with the equilibrium facts was provided by the Langmuir model isothermally and Pseudo-Second-Order kinetically at 298 K, with a maximum adsorption capacity of 382.7 mg.g−1. A spontaneous endothermic process was validated using the thermodynamic characteristics. The results of kinetic investigations, which were fitted to a pseudo-second-order model, displayed that equilibrium was got after 90 min. In terms of adsorption kinetics, the experimental results can be represented by the linear driving force model. Additionally, the projected adsorption data of the model agree with the results of the experiment. Box Behnken design study may also show the ideal circumstances for greater atrazine elimination by Ru-MOF. Hydrophobic, π–π interactions and pore filling processes that take place at the surfaces may be used to govern the adsorption mechanisms. When the adsorption capacity was compared to the literature review, it was determined that the Ru-MOF had the best adsorption capacity out of all the preceding adsorbents. Check the adsorbent's regeneration as it demonstrated good efficiency for five cycles, which was deemed a significant cost-saving benefit.

Adsorptive properties of highly porous activated carbon from açaí (Euterpe oleracea) towards the toxic herbicide atrazine

The great variety and possibilities of consumption of açaí pulp (Euterpe oleracea) have made its consumption increase considerably in recent years, mainly in Brazilian territory. The big problem is the generation of tons of waste that characterizes the fruit stone. This waste was converted into a highly porous activated carbon and employed to remove the herbicide atrazine. The characterization analyses confirmed that the applied methodology generated an adsorbent with good textural characteristics (specific surface area 920.56 m² g−1, pore volume 0.467 cm3 g−1; average pore diameter 1.13 nm). Furthermore, it was found that the adsorption of atrazine reached satisfactory results at natural pH and with an adsorbent mass of 0.54 g for each liter of solution. The Redlich-Peterson model presented the most satisfactory fit with the equilibrium data. This study found that the evolution of system temperature increased the concentration in the solid phase of 178 mg g−1 at 328 K. Regarding adsorption kinetics, the linear driving force model can represent the experimental data. Also, the predicted adsorption data of the model follows the experimental data. The application of the adsorbent in the removal of the herbicide mixture presented an efficiency of 81.45%. Therefore, using residual açaí fruit seeds as biomass for producing activated carbon employing zinc chloride as an agent activator is the possible application of the material. The material showed high efficiency and affinity with the target molecule.

The Effect of Adding Prim ary Epoxy on the Corrosion Rate of Low Carbon Steel in 5.25% Calcium Hypochlorite Solution

The corrosion process occurs in almost all materials, especially metals, slowly but surely, which can cause a material to have a limited service life. Corrosion cannot be prevented but the rate can be reduced. One of t he methods to inhibit the effective corrosion rate is by giving epoxy primer treatment. This study aims to examine the effect of adding epoxy primer on the corrosion rate of low carbon steel immersed in a 5.25% Calcium hypochlorite solution. This research was conducted using 27 specimens in 9 vessels, each vessel contained 3 specimens immersed in low carbon steel without treatment, oil paint and epoxy primer. Volume of 1 liter of solution for 1 vessel. The results of this study indicate that the epoxy primer is able to inhibit the corrosion rate well. The reduction in weight of low carbon steel treated with oil paint is much greater than that of untreated low carbon steel using epoxy primer. The lowest corrosion rate was given by applying epoxy primer in 30 days of immersion with an average value of 0.001001695 mpy and the highest corrosion rate without treatment in 15 days of immersion with an average value of 0.005008473 mpy.

Effect of Giving Organic Waste-Based Poc To The Growth of Kailan Plants (Brassica Oleracea L)

This study combined the use of variable doses of liquid organic fertilizers made from organic waste, wich a Factorial experimental study that uses a Randomized Group Design (RAK) consisting of 2 treatment factors. Factor I treatment is a type of POC raw material consisting of 7 levels: P0= Comparison without the provision of liquid organic fertilizer, but given basic fertilizer; P1= Given POC made from a mixture of materials 2 to 7; P2=Given POC made from vegetable waste (tomatoes and mustard); P3= Given POC made from waste fruits (bananas and papaya); P4= Given POC made from germinated waste; P5= Given POC made from waste food catering; P6= Given POC made from catfish waste; P7= Given POC made from animal slaughterhouse waste (cow's blood). The treatment of Factor II is the concentration of POC giving includes 3 levels, namely: K1= POC concentration of 4%=40 ml/ liter of solution; K2= POC concentration of 8%=80 ml/liter solution; K3= POC concentration of 12%=120 ml/liter of solution. The parameters of observations made on kailan plants include: the number and length of the plant. By comparing the concentration treatment of K1, K2 and K3 mentioned above, the K2 treatment (concentration of 8% POC) exerts a better influence than the treatment of K1 and K3, although it is not real from the K3 treatment. This shows that the use of POC made from organic waste with a concentration of 8% POC provides a significant influence that can play a role in increasing soil fertility and plant productivity.

A THE EFFECT OF DOSE AND TIME OF ADMINISTRATION OF TRICHODERMA SP ON FUSARIUM OXYSPORUM ON SHALLOT (Allium ascalonicum L)

ABSTRACT
 This studypaimsptopdeterminepthe appropriate dosepand time ofxadministration ofxTrichoderma sp to control Fusarium oxysporum disease in shallot plants. Thepresearch waspconductedpfrompSeptemberp2020ptoxDecemberx2020 in Karangasem Hamlet, Guli Village, Nogosari District, Boyolali Regency. Thispstudypusedpapfactorialpcompletely randomizedpdesign (RAL) methodpwhich consisted ofp2pfactors. Thepfirst treatmentpfactor was thepdose ofpTrichoderma sp (D) which consisted of 3 g, 5g, 7g and the time of administration (T) which was one week before planting, during planting and a week after planting. Parameterspobservedpwerepnumberpof leaves, number ofptubers, weightpof fresh stover, weight of dry stover and intensity of disease attack. The results showed that the treatment with the best Trichoderma sp (D) dose was obtained in the D3 treatment with a dose of 7 grams / liter of solution had a very significant effect on the number of leaves, fresh stover, dry stover, intensity of disease attack and not significantly different on the number of tubers. The best time treatment for giving Trichoderma sp (T) was obtained in T1 treatment, namely the time of administration one week before planting had a significant effect on the number of leaves, fresh stover, and was not significantly different on the number of tubers, dry stover, intensity of disease attack. Meanwhile, the best combination of dosage and time of administration of Trichoderma sp was obtained in the (D3T1) treatment, namely the administration of a dose of 7 grams / liter of solution and the time of administration one week before planting had a significant effect on dry stover and had no significant effect on other parameters.
 
 Keywords : Trichoderma sp, fusarium oxysporum, shallot.

A vacancy-free sodium manganese hexacyanoferrate as cathode for sodium-ion battery by high-salt-concentration preparation

Sodium manganese hexacyanoferrate (MnPBA) is attracting wide attention as an ideal low-cost cathode material for sodium-ion batteries (SIBs) because of high specific capacity, three-dimensional open framework, and low cost. However, some issues, including high [Fe(CN)6]4- vacancy concentration, a large amount of structural water in lattice, and nano-scale particles, hinder the practical application. Here, the effects of coprecipitation process under high-salt-concentration solution were systematically investigated to prepare a vacancy-free MnPBA with micro-spherical particle morphology. The sample (PBAT-80), prepared at ageing temperature of 80 °C for ageing time of 20 h, achieved high yield of 100 g L−1 (w/v = weight of production / liter of solution) and theoretical reversible capacity of 170 mAh g−1. Moreover, the relationship between crystallinity and thermal stability of MnPBAs was further investigated and the different storage mechanisms of distinct water molecules were identified. These results will be attractive for commercial applications of SIBs in large-scale energy storage systems.

Prevention of postoperative peritonitis and its complications

Purpose: to develop a new method of lavage of the abdominal cavity in the experimental conditions.Materials and methods. We treated 456 patients with postoperative peritonitis who were on treatment in the surgery department of the municipal non-profit enterprise Regional Clinical Hospital of Ivano-Frankivsk Regional Council in the period from 2000 to 2021. Patients are divided into 2 groups. The retrospective group consisted of 212 patients, prospective - 244 patients.Research results and their discussion. The method of lavage of postoperative peritonitis was carried out as follows: during relaparotomy, after mechanical cleaning of the abdominal cavity from fecal masses, bile, blood clots, fibrin layers, the abdominal cavity washed twice with 2-3 l of 0.02% solution of decamethoxine at a temperature of 30-35 ° C. After removing the drug residues from the abdominal cavity, pour2 liters of solution for peritoneal dialysis Extranil at a temperature of370C, the active substance of which is icodextrin, not glucose, ie it is not a nutrient medium for microorganisms, but has antimicrobial action due to hyperosmolarity and exposure to hyperosmolarity and increases its adsorption properties. This is followed by drainage of the abdominal cavity from four points with polyvinyl chloride tubes, which are intimately fixed to the skin and blocked for 6 hours.

Efficiency of <i>Verbascum densiflorum</i> Bertol. bioregulators in stimulation of vegetable growth and development

Relevance. Increasing the resistance of vegetable plants to unfavorable growing conditions with the use of growth regulators that actively affect the seed quality, increase the survival rate of seedlings, stimulate the setting, formation and maturation of the crop is a significant reserve for increasing productivity with the already achieved level of intensification of their production.Material and methods. The effect of verbascosides obtained by exhaustive extraction with 60% aqueous ethyl alcohol from the aboveground part of Verbascum densiflorum Bertol. (Scrophulariaceae) was studied on the germination, growth, development and yield of tomatoes, cucumbers, onions and white cabbage. Before sowing, the seeds were soaked in an aqueous solution of verbascosides for 15-20 minutes, followed by drying to flowability at the rate of 0.5-0.8 liters of solution per 1 kg of seeds.Results. It is shown, that possessing phytoregulatory activity and influencing the metabolic and synthetic reactions of plants, these compounds, applied exogenously, stimulate the seed germination energy and total germination of vegetable crops, provide simultaneous appearance of seedlings and optimal plant density, accelerate the growth dynamics of plants assimilation surface and fruit mass. Reducing the consequences of stresses arising in the process of plant growth and development, they thereby contribute to increasing plant resistance, productivity and improving the commercial quality of the products. The ability of these compounds to improve the production process of vegetable crops, depending on the type and variety of vegetables was established. Their highest stimulating effect was determined on cabbage variants, where the yield exceeded the control by 34.3%. The performed studies and obtained results allow to recommend the pre-sowing seed treatment with a 0.01% solution of biological active substances from Verbascum densiflorum Bertol. as an element in technology of growing vegetable.

Elimination of pharmaceutical pollutants by solar photoelectro-Fenton process in a pilot plant

In this study, the simultaneous degradation of antibiotics (ampicillin, sulfamethazine, and tetracycline; and non-steroidal anti-inflammatories (diclofenac and salicylic acid)) including the total organic carbon abatement by solar photoelectro-Fenton process was assessed. Eight liters of solution containing the mixture of the five pharmaceuticals in 1mmolL-1 Fe2+, 0.05molL-1 Na2SO4 at pH3 and 35°C were electrolyzed applying different current densities (j = 10, 25, and 50mAcm-2) in a solar-electrochemical pilot plant. The pilot plant was equipped with an electrochemical filter press cell with a dimensionally stable anode (DSA type) and an air-diffusion cathode coupled to a solar photoreactor exposed directly to sunlight radiation. All pharmaceuticals were degraded during the first 10min. A TOC removal efficiency of 99.2% after 100min of treatment with an energy consumption of 534.23kWh (kgTOC)-1 and 7.15kWhm-3 was achieved. The pharmaceutical concentration decay followed a pseudo-first-order kinetics. The specific energy per unit of mass of ampicillin, diclofenac, salicylic acid, sulfamethazine, and tetracycline was obtained at 11.73, 19.56, 35.2, 11.73, and 39.32kWh (kgPD)-1 for ampicillin, diclofenac, salicylic acid, sulfamethazine, and tetracycline, respectively. With our results, we demonstrated that SPEF is an emerging technology for the treatment of this type of pollutants in short time.

ИСПЫТАНИЕ ОГНЕЗАЩИТНОГО ДЕЙСТВИЯ СОЕДИНЕНИЙ АЛЮМИНИЯ И БОРА ДЛЯ БОРЬБЫ С НИЗОВЫМИ ПОЖАРАМИ

The fight against ground forest fires includes three measures: (1) preventing the occurrence, (2) limiting the spread, and finally, if the first two did not help, (3) extinguishing the edge of the fire. It is impossible to completely eliminate the factors contributing to the onset and development of fires in these territories. Therefore, measures to prevent the free spread of fire will be the most effective ones. A method is proposed to prevent and limit the spread of ground fire by creating fire-retardant strips. These are areas covered with grass and plant debris, treated (by spraying) with aqueous solutions of aluminum hydrogels. The efficiency of the flame retardant properties of such strips has been studied during field experiments. It has shown that obvious signs of fire-retardant effect of aluminum hydrogel begin to appear at a concentration of 7 g/l, with a flow rate of 1 liter of solution per 1 m2 of the treated area. In this case, ground fire loses its stability and its speed decreases 2-3 times. The treatment of the plots with hydrogel solutions with a concentration of 14 g/l or more completely prevented the spread of the flame over the grass cover. In addition, attempts to force the site to burn (28 g/l) were unsuccessful. A water-soluble compound of boron - sodium tetraborate - with concentrations of 3.5-28 g/l does not have sufficient fire retardant action to stop the spread of ground fire.

Water productivity and agronomic performance of strawberries with different leaching fractions application

Strawberry is an economically important crop. However, because this crop is very susceptible to pests and diseases, the use of new management techniques, such as semi-hydroponic cultivation, is necessary. One of the greatest difficulties for producers in the transition from soil to semi-hydroponic cultivation is fertigation management. As most crops in Brazil are grown in open fields, monitoring the electrical conductivity of the drained solution is key. Thus, the aim of this study was to use different leaching fractions to evaluate the control of saline levels and the productivity of the San Andreas strawberry. The experimental design was completely randomized. The treatments consisted of different leaching fractions, equivalent to 10, 20, 30, and 50% excess irrigation. Most of the evaluated traits were significantly affected at the 5% level of significance according to Tukey’s test. The 30% leaching fraction showed the best results in practically all evaluations, with better values obtained even for water productivity and with 19.92 g of fruit per liter of solution used.

Sequential gas-liquid treatment for gaseous toluene degradation by Fenton’s oxidation in bubble reactors

A lab scale bubble reactor (BR) configuration was employed to evaluate the degradation of gaseous toluene by Fenton’s oxidation under semi-batch mode operation (i.e., with continuous gas bubbling in the liquid phase where organics oxidation is carried out). A parametric study was performed for evaluating the effect of Fenton’s process operating parameters, such as temperature and concentration of Fe2+ and H2O2, in the removal of toluene from the gas stream. The maximum amount of toluene transferred (0.041 mol per liter of solution) was reached when the optimal conditions ([Fe2+] = 2.5 mM, [H2O2] = 20 mM, and T = 25 ºC, at pH 3.0) were used after 120 min of reaction, yielding the highest average toluene absorption rate (5.78 × 10−6 mol/L.s). The treatment of the gas stream increased, however, the organic load in the aqueous phase, so a subsequent treatment stage of the liquid was performed. Additionally, a scale-up of the sequential gas-liquid treatment for a bubble column reactor (BCR) was carried out for several cycles, up to almost 20 h. This strategy, making use of the Fenton’s process for treating the toluene gas stream, with intermediate liquid oxidation, allowed to reach more gas treatment stages, while providing a final effluent that is non-toxic (0.0 % of inhibition of Vibrio Fischeri) and biodegradable.

Advanced Oxidation of Antibiotics Polluted Water Using Titanium Dioxide in Solar Photocatalysis Reactor

The aim of this study was to investigate antibiotic amoxicillin removal from syn­thetic pharmaceutical wastewater. Titanium dioxide (TiO2) was used in photocatalysis treatment method under natural solar irradiation in a tubular reactor. The photocatalytic removal efficiency was evaluated by the reduction in amoxicillin concentration. The effects of antibiotics concentration, TiO2 dose, irradiation time and the effect of pH were studied. The optimum conditions were found to be irradiation time 5 hr, catalyst dosage 0.6 g/L, flow rate 1 L/min and pH 5. The photocatalytic treatment was able to destruct the amoxicillin in 5 hr and induced an amoxicillin reduction of about 10% with 141.8 kJ/L accumulated solar energy per liter of solution.

Simultaneous treatment of agro-food and asbestos-cement waste by the combination of dark fermentation and hydrothermal processes

The inadequate management of asbestos-cement products (ACP) and/or wastes (ACW) generates hazardous airborne dusts. For this reason, the EU is promoting the removal of ACP from utilities, public and private buildings and is looking for innovative ACW treatments alternative to the landfilling. The simultaneous treatment of ACW and orange pulp or cheese whey was attempted with a mesophilic dark fermentation (DF) process followed by a 12 h hydrothermal (HT) treatment carried out with the addition of lactic or oxalic acid at 100 °C and ambient pressure. The DF of orange pulp or cheese whey in the presence of 5 g L−1 ACW lasted 171 h and led to the production of 4 LH2 and 5 LH2 per litre of solution, respectively. During the DF, the dissolution of the ACW matrix was almost completed, and the partial collapse of the asbestos fibres was observed. Both the organic acids that were added during the HT tests at a concentration ≥2.5 g L−1 completely destroyed the asbestos fibres. However, when 1.25 g L−1 lactic or oxalic acid was added before the HT tests, few fibre fragments were found, and their chemical composition differed from that of chrysotile.

A homogeneous liquid reference material for monitoring the quality and reproducibility of in situ cosmogenic 10Be and 26Al analyses

Analysis of the in situ produced cosmogenic nuclides 10Be and 26Al has been used for several decades to study Earth surface processes; yet, no reference material has been widely adopted and used by the community to ensure the quality and comparability of sample preparation and isotopic analyses. Such a reference material could facilitate inter-laboratory comparison and serve as a benchmark for quantifying the accuracy, precision, and long-term reproducibility of terrestrial cosmogenic nuclide analyses. Here, we describe a liquid reference material, UVM-A, which is freely available to the community. We created four liters of solution by dissolving CRONUS-A granular reference material [1], and spiking the solution with stable 9Be and 27Al, yielding a solution containing 236.7 ± 0.6 μg g−1 Be and 932.6 ± 1.6 μg g−1 Al (average, 1SD). Initial analyses of UVM-A indicate that the nuclide ratios of the reference material (10Be/9Be 1.43 ± 0.02 × 10−13; 26Al/27Al 4.44 ± 0.05 × 10−13; average, standard error) are similar to those of late-glacial exposure samples, are tightly clustered, and match the nuclide concentrations expected from the CRONUS-A quartz used to prepare the reference material. Use of this reference material will help to quantify uncertainty in cosmogenic exposure ages, burial ages, and erosion rates resulting from sample preparation and isotopic analysis.

Efficiency of complex disinfecting measures in the conditions of poultry farm-ing

The key to successful work of a modern poultry industry and the safety of its products for consumers is high-quality disinfection. Modern disinfectants used in poultry farms are different in composition, concentration of active substances, means of application and other properties. Most of them are represented by imported products. Their replacement in the domestic market with effective, safe and economical drugs is extremely relevant. It should be highly effective means, possessing a wide spectrum of virilicidal, bactericidal, sporocidal and fungicidal action. The goal of the work. The purpose of our research was to evaluate the effectiveness of the complex disinfection in the production conditions of the Bi-Dez and DezSan products. Materials and methods of research. Production testing of the disinfection of poultry facilities and equipment using the Bi-dez and DezSan schemes was carried out at one of the poultry farms of the Sumy region. At the first stage, the water supply system was treated by filling the piping line with a 0.1% solution of Bi-dez with an exposure of 1 hour. At the second stage, moisture was disinfected with 0.8% solution DezSan from the rate of 0.2–0.3 liters of solution per 1 m2, exposure time – 2–3 hours. Then, in the room, the fine dispersed aerosol of this biocide was sprayed into a 10% solution (1 liter of preparation per 9 liters of water) – aerosol disinfection by fogging at a rate of 5 ml of solution per 1 m3 of space, exposure time – at least 3 hours. Results of research and discussion. Evaluating the effectiveness of disinfection of the water supply system with the Bi-dez compound, found that the total microbial contamination of the water before treatment was 235 CFU/ml. In addition to other bacteria, it was isolated from the intestinal bacillus. After the rehabilitation, the microbial water pollution decreased to 4 CFU/ml. Sanitary-indicative microorganisms (E. coli, salmonella and staphylococci) were not detected in the system faults. The total amount of microorganisms in the air after disinfection with the drug DezSan decreased by 2.6 times (12 thousand mc/m3) compared with the baseline bacterial background (29 thousand mc/m3), and the intestinal rod after treatment from the selected in the poultry house air samples were not allocated. Conclusions and prospects for further research. Reducing the microbial background and the death of opportunistic microorganisms in the premises and the system of drinking poultry farms contribute to the veterinary well-being of poultry farms. In the future, it is planned to conduct a study of the drug DezSan, identified it irritating, skin-resorptive, cumulative and other properties.

Phytoremedial potential of aquatic macrophytes for the removal of copper in contaminated waters

The aim of this study is to identify the potential aquatic macrophytes to be used for phytoremediation and to compare the reduction of copper by two species of aquatic plants. Two aquatic plants; Centella asiatica and Eichhornia crassipes, the effectiveness were evaluated for their capabilities of copper removal from copper solution. The aquatic macrophytes were placed for 7 days in 6 liters of solution that contained 1 mg/L, 3 mg/L and 5 mg/L of copper. Atomic absorption spectrometer (AAS) was used to conduct analyses of heavy metals contents. It was shown in the results that Centella asiatica achieved complete removal of 1 mg/L copper concentration after the third day of treatment. Centella asiatica also displayed maximum removal of 92% of 3 mg/L copper concentration and 62% for 5 mg/L copper concentration. The peak efficiency at the end of the experiments were at almost similar for Eichhornia crassipes, 83% for the 1 mg/L concentration, 80% for the 3 mg/L concentration and 83% for the 5 mg/L concentration. Overall, Centella asiatica exhibit faster removal rate of copper compared to Eichhornia crassipes. In terms of effectiveness, the percentage removal in solution was higher using Centella asiatica at lower concentration of copper. However, at higher concentration of copper (5 mg/L), Eichhornia crassipes was found to be more effective in removing copper compared to Centella asiatica.

Green Synthesis of Resin Supported Nanoiron and Evaluation of Efficiency for the Remediation of Cr(VI) Contaminated Groundwater by Batch Tests

In this study the fixation of nano zero valent iron (nZVI) on a polymeric matrix applying an environmentally friendly technique and the performance of this material for the treatment of Cr(VI) contaminated groundwater were evaluated. The investigated method could be applied in a pump & treat groundwater remediation system. A macroreticular cationic resin was selected as porous host material. It was found that green tea polyphenols were able to penetrate within the macroporous resin matrix and obtain the reduction of Fe(III) to the elemental state. The effectiveness of this composite material in removing Cr(VI) contaminated waters was evaluated by conducting batch tests. It was found that the reduction of Cr(VI) follows a kinetics law of first order with respect to the concentration of Cr(VI) and to the amount of nZVI per liter of solution. The kinetic constant varied between 5·10-3 and 0.5·10-3 per min and per mM of nZVI in the pH range 3.5-7.5.