ARTIFICIAL COMPACTION GIVEN BY PENETRATION RESISTANCE IN SOILS WITH DIFFERENTUSE

Heavy agricultural machinery is major cause of one of the processes of soil degradation, compaction, which became a problem of significant proportions, especially on soils with high moisture. Excessive traffic affects soil quality and crop production, and also causes environmental problems.The paper presents the results of research conducted to determine soil compaction on three experimental fields: plot of energy willow, plot of clover and cherry orchard, while different moisture contents represent subfactor. Maximum penetration resistances were recorded at 45 cm depth, where the soil is severely compacted: 3194.5 kPa on the soil cultivated with energy willow, 2984kPa in the orchard, respectively 3069kPa on the plot of clover

APPLICATIONS OF ROTATING BIOLOGICAL CONTACTORSIN WASTEWATER TREATMENT

Rotating biological contactors are generally used as secondary treatment of domestic, hospital and industrial wastewater, operating asan aerobic and anaerobic fixed film biological treatment. Rotating biological contactors areeffective in the removal of biodegradable matter,pathogenic bacteria,nitrogen, recalcitrant compounds, heavy metals,emerging contaminants, and dyes from wastewater. In this paper, we present the design and operating principles of rotating biological contactors, and we review some of the most important results related to the applications of rotating biological contactors for the treatment of wastewater originating from different activities

NANOMATERIALS FORHEAVY METALS REMOVAL FROM WASTEWATER

Human, agricultural, industrial, and mining activities generate large quantities of wastewater contaminated with toxic and non-biodegradable heavy metals such as As, Cr, Cd, Co, Cu, Hg, Ni, Pb and Zn.To avoid the harmful effects of heavy metals on terrestrial and aquatic ecosystems and on human health, it is essential to develop and implement innovative technologies for the removal of these toxic and hazardous pollutants from wastewater.In wastewater treatment, and particularly in nanotechnology applications, many efficient, ecological and cost-effective nanomaterials have been developed, having unique functions of heavy metals removal from industrial effluents, surface waters, groundwater and drinking water.Due to their antimicrobial properties, nanoparticles are also used for wastewater disinfection and microbial control

ELECTROCOAGULATION IN WASTEWATER TREATMENT

Within the past decades,water scarcity is one of the greatest challenges faced by humans, sothe treatment and reuse of wastewater generated daily from household, sanitary and industrial activities iswidely practiced and encouraged.Electrocoagulation has emerged as an effectivetechnology for the treatment ofdifferent categories of wastewater. The electrode materials should non-toxic to human health and environment and these usually involve aluminium or iron, but new materials are also used.The efficiency of electrocoagulation depends on current density, gap between anodes and cathodes, electrodes arrangement, composition and shape, initial pollutant concentration, composition and pH of the solution, electrolysis time.This paper aims to reviewthe mechanisms involved in wastewater electrocoagulationand the results of electrocoagulation applied in the treatment of wastewater from different sources

THE EFFECTS OF WASTEWATER IRRIGATION ON AGRICULTURAL SOILS

In arid and semi-arid areas, wastewater is often recovered for crop irrigation, contributing to the sustainable agriculture. Although positive effects have been observed on crop yields (50-80% growth) due to wastewater nutrients, the reuse of untreated wastewater harms both the environment and human health. Soil is mostly affected by excess salts, sodium, nutrients and heavy metals in wastewater. High salinity affects the upper layer of soil (0–30 cm); sodium and chlorine reduce crop yields by 40%; high content of organic matter in wastewater decreases soil pH, and heavy metals and pathogens enter the food chain. Irrigation technology is also important: sodium and salinity are higher in sprinkler than in furrow or subsurface irrigation; subsurface drip irrigation is more effective in reducing soil pathogens than surface drip irrigation. This paper examines the effects of wastewater irrigation on soil salinity, sodium, heavy metals and pathogen contamination

ANALYSIS OF THE STATE OF STRESSES AND STRAINS IN THE CURVED STILT, USING TRIANGULAR FINITE ELEMENTS (CST)

The paper presents a study on the analysis of the distribution of stresses and strains in the curved stilt of the plough-body, using the Finite Element Method. Modeling was performed with the help of triangular finite elements "CST" (Constant Strain Triangle), using a special program for this type of applications “CSTPL.EXE”, developed at University Politehnica of Bucharest, Department of Materials Strength

STRUCTURAL STATIC ANALYSIS OF THE CURVED STILT BY FEM USING THE ELCUT PROGRAM

The paper presents a study of the distribution of stresses and strains in the curved stilt of the plough-body, using the ELCUT analysis program by the finite element method. In its public version, the program allows the static structural analysis in three stages of precision. However, there are some limitations on the number of nodes for the discretized structure, depending on its complexity (250 to 500 nodes)

UV DISINFECTION - A METHOD OF PURIFYING WASTEWATER FROM FARMS – A REVIEW

The livestock industry increased significantly globally due to increasing demand for animal products. There are however, growing concerns on the environmental risks, associated with the disposal of untreated livestock wastewater into streams and rivers. Disinfection is considered to be the primary mechanism for the inactivation/ destruction of pathogenic organisms to prevent the spread of waterbornediseases to downstream users and the environment.Water disinfection using ultraviolet light is a newer process that currently has a limited use area [5].The purpose of this paper is to present the ultraviolet disinfection process used for the treatment of waste water

STUDIES AND EXPERIMENTAL MEASUREMENTS FOR AUTOMATED CONTROL OF CONVEYOR BELTS

The transport of raw from bunkers to the work installations is a very important activity from the technological flow that takes place in a compound feed factory. So it is indicated to exist an automated control of the conveyor belts, to ensure the proper functioning of the work equipment. The experimental measurements were made using an own conception electronic assembly. Thus it was possible to analyze the operating parameters of rotation and proximity magnetic sensors, which can be used to implement devices that allow automated control of conveyor belts. Studies of measurements shown in this article offer the possibility of implementing automated control devices based on magnetic sensors, which allow the transmission of stop signals of motors that drive the conveyor belts at detection of disturbances in their normal operation, to maximize losses of materials

ADVANCED TECHNOLOGIES FOR WASTEWATER TREATMENT BY UV – A REVIEW–

Reclamation and reuse ofwastewater is one of the most effectiveways to alleviatewater resource scarcity.Disinfection plays a key role in reuse of wastewater for eliminatinginfectious diseases.Water disinfection using ultraviolet light is a newer process that currently has a limited use area. Ultraviolet(UV) disinfection is now widely implemented as a tertiary treatment forwastewater reclamation. The purpose of this paper is to present the most representative studies on the use of ultraviolet in wastewater treatment