Synthesis of Zeolite from Fly Ash and their Use as Soil Amendment

The amendments may be natural or synthetic and by their origin organic or inorganic. Among amendments, the inorganic ones are recommended, such as gypsum, lime, zeolites and altered rocks, including sand, ceramic, perlite, ash, slag, zeolite, pyrites, dolomite, calcined clay, etc. Fly ash-based zeolites can be used as amendments to improve the use of the soil for agricultural purposes. Generally, there are different methods for the synthesis of new materials using solid waste – fly ashes. Methods are known to be composed of a single stage or two stages. The first method – the conventional – is direct hydrothermal conversion of the mixture of ash and alkaline solution (NaOH or KOH), but only 50% of ashes can be converted into zeolite. The second method consists in mixing the ash with KOH and fusion at elevated temperature. The method leads to an advanced conversion – the type of zeolite depending on treatment conditions. Other studies recommend the conversion of ash using microwave ovens or ultrasound bath; in this case, the conversion time is reduced to 1–2 hours. From these methods, the direct method was proposed to be used in synthesizing zeolites for agriculture, with a part in controlling release of fertilizers and as a soil amendment. The synthesized materials were characterized with respect to microstructure (electronic microscopy SEM) and chemical and mineralogical composition (EDAX, X-ray diffraction). By analyzing the obtained data, one may observe the destruction of the ash network and crystallization of the zeolitic phase, especially in the case of treatment by diffusion. The XRD analysis confirms the presence of zeolite in materials obtained. Good results were also obtained in the case of using ultrasound treatment for zeolite synthesis; also, the time of treatment significantly decreased in this case

Technical Efficiency of the Subsurface Drainage on Agricultural Lands in the Moldova River Meadow

This study aims to investigate the technical efficiency of different subsurface drainage variants, in terms of the depth of the tile drains, spacing between the drain lines, type and thickness of the drain + filter complex, and the improvement procedures. Within the four variants, the discharge rate of the soil moisture excess was studied. In variants A and D, the spacing between drains is 20 m, and in the variants B and E, the spacing is 15 m. The depth of the tile drains is 0.8 m in variants D and E and 1.0 m in variants A and B. In variant A, tile drainage was combined with land shaping in the bedding system with top of ridges and furrows. Soil moisture was determined on checkpoints placed on drain cross section, at 2 m from drain lines, and of the middle of the drain spacing. In the version with land shaping, the drain lines located under the furrows favor the excess moisture removal. A similar technical efficiency was recorded in unimproved variant but with spacing between drains of 15 m. Best efficiency at removing excess water was registered in variant of the filtering material from ballast associated with flax strains

IRRIGATION STATION EQUIPMENT FOR PREVENTING THE USE OF LOW WATER QUALITY

In Romania the economically efficient irrigated area is estimated at 3.5 million hectares. On national scale there is nointegrated approach for monitoring the quantity and quality of the irrigation water, using adequate equipment at thepumping station. On international scale, in many countries the pumping stations are provided with equipment formonitoring, on real time, the quality or the pumped water and for warning about critical situations (emergencies).This paper describes a technical solution consisting of equipment which monitors the following parameters of waterpumped in irrigation systems: turbidity, pH, CE at 25 o C, Na+, Cl-. The lapse of time for monitoring is of 10 to 60 min.The main components are the following: the sampling pump (submersible) the monitoring board, the repression pipe ofthe analyzed water. Warnings are made about values exceeding the programmed level for each monitored parameter,about the fact that the pump and agitator do not work or about any other source of damage.The technical solution and equipment were tested at a pumping station which uses water from Danube, in most casesmixed with water originating from drainage. Results showed a reduction of the total content of soluble salts from soiland of their negative impact upon the crops, a reduction of the degree of river alluvial deposits within the irrigationsystem and reduction of the energetic consumption required for pumping

Studies on green areas design in Belin commune, Covasna county

This article presents a practical study realized when preparing the technical project for landscaping, by realizing green areas in Belin commune, Covasna County. The project involves the arrangement of new green areas which are currently not arranged and the increase of the green areas surface in Belin locality, the endowment with street furniture of such arrangements in order to improve and rehabilitate the urban public infrastructure and the execution of a playground. By complex and appropriate interventions, thus land of over two hectares shall be arranged as Public Park, with endowments addressing persons of all ages, an opportunity for meetings and relaxation in the said area (HG 321/2005). Such aims shall be achieved by means of rest areas in a planted space, appropriate for walks and relaxation and for the execution for children playgrounds

Irrigation system design of the landscaping plan of "Lacul Dulce Brăila" park

This study was conducted during the design and execution works of an economically and competitive irrigation system for the „Lacul Dulce” Park, located in Braila. Technical project planning of the irrigation system is a vital component in the overall project planning of the park, built to improve quality of the environment and the green space area that is available per capita. The irrigation project is fully integrated and consists in automated, competitive and efficient equipment which is functioning at the designed parameters that allow sustainable use of landscape of the park and provide benefits to the population the area

Première identification en subsurface de calcaires d'eaux peu profondes attribués au Crétacé basal dans la Dépression de Transylvanie (Roumanie)

Triassic, Upper Jurassic and upper Lower Cretaceous sedimentary formations were previously studied from the Transylvanian Depression basement, but the presence of lowermost Cretaceous (Berriasian-Valanginian) has not been confirmed paleontologically. The carbonate sequence cored from a borehole drilled in the central part of the Transylvanian Depression yields microfossil assemblages dominated by benthic foraminifera. These new data unequivocally document the presence of characteristic Berriasian-Valanginian taxa in these deposits

Legislative and administrative support scheduled for improving the environmental quality by creating green spaces in the cities

Improving the environmental quality by creating green spaces is a key factor in the development of populated areas by positive general impression and benefits of aesthetic, social, economic and public health nature in the intervention areas. This study analyzed the effects of "The national program to improve the environmental quality by creating green spaces in cities" aiming at the staged, controlled and prioritized development of green spaces to achieve the objectives of Romania under the accession to the European Union and to undertake the obligations under the Community Environmental Policy. Thus, in Romania through the implementation of this program, the national efforts have increased both administratively and economically and socially as regards the programming, design and execution of green spaces in cities, both as new sites, and as the rehabilitation or expansion of the existing ones

Statistical Analysis of the Tensile Strength of Coal Fly Ash Concrete with Fibers Using Central Composite Design

The influence of coal fly ash and glass fiber waste on the tensile strength of cement concrete was studied using central composite design. Coal fly ash was used to replace 10% of the cement in the concrete mix. Glass fiber was added to improve the tensile properties of the concrete in different dosages and lengths. In total, 14 mixes were investigated, one only with 10% coal fly ash replacement of cement and the other thirteen were determined by the experimental design. Using analysis of variance, the order of importance of the variables was established for each property (flexural strength and split tensile strength). From the nonlinear response surfaces, it was found that higher values of flexural strength were obtained for fibers longer than 12 mm and at a dosage of 1-2%. For split tensile strength, higher values were obtained for fibers with a length of 19–28 mm and at a dosage of 1–1.5%

Screening of Molecular Virulence Markers in Staphylococcus aureus and Pseudomonas aeruginosa Strains Isolated from Clinical Infections

Staphylococcus (S.) aureus and Pseudomonas (Ps.) aeruginosa are two of the most frequently opportunistic pathogens isolated in nosocomial infections, responsible for severe infections in immunocompromised hosts. The frequent emergence of antibiotic-resistant S. aureus and Ps. aeruginosa strains has determined the development of new strategies in order to elucidate the different mechanisms used by these bacteria at different stages of the infectious process, providing the scientists with new procedures for preventing, or at least improving, the control of S. aureus and Ps. aeruginosa infections. The purpose of this study was to characterize the molecular markers of virulence in S. aureus and Ps. aeruginosa strains isolated from different clinical specimens. We used multiplex and uniplex PCR assays to detect the genes encoding different cell-wall associated and extracellular virulence factors, in order to evaluate potential associations between the presence of putative virulence genes and the outcome of infections caused by these bacteria. Our results demonstrate that all the studied S. aureus and Ps. aeruginosa strains synthesize the majority of the investigated virulence determinants, probably responsible for different types of infections