Closed Water Circulation Research Articles

Analysis of effect cooling tower geometric porforation design on the distribution of sound pressure level and temperature

Abstract Noise in a cooling tower system is caused by the cooling system engineering units, namely the tightly closed water circulation pump, fans for air flow needed for heat transfer, and vibrations in the cooling tower structure. Noise in cooling towers can be reduced by paying attention to the mechanical structure of the cooling tower such as stiffness, density and porosity of the cooling tower material. This mechanical control is still not optimal for reducing or controlling noise at low frequencies, depending on the physical properties of the materials used. The objective of the study is to analyze the noise distribution in the cooling tower geometric design and the temperature distribution in the cooling tower geometric design. This research focuses on the geometric design of the cooling tower and selecting the most optimal design to reduce noise and analyze the temperature distribution in the cooling tower. In this paper, simulations were carried out using the Ansys Harmonic Acoustics program and carried out at low frequencies, namely frequencies of 100 - 500 Hz. The simulation is carried out by placing the noise source in a chamber surrounded by a barrier or enclosure. The results of the simulation include the distribution of Sound Pressure Level (SPL) and air temperature distribution in the form of a countour plot which displays color gradations in the geometry which indicate differences in sound intensity values and air temperature values in the cooling tower geometry. After obtaining the simulation results, the most optimal design can be identified to reduce noise in the cooling tower.

Thermodynamic comparison of the operation of the HDH system with water heating or air heating in closed water circulation and semi-open-air circulation

The present study focuses on doing a thermodynamic analysis of a desalination system that utilizes the humidification–dehumidification (HDH) process with semi-open-air (SOA) circulation. The HDH desalination system is a notable example of a developed system utilized for freshwater production. This system has the advantage of being able to derive its energy from solar sources. The categorization of desalination units is determined by the configuration of their components, the direction of water and air movement, and the kind of heating employed for each stream. The present study noted that the utilization of this particular air circulation strategy, while maintaining a constant maximum system temperature, leads to enhanced system efficiency when combined with water heating. However, no substantial impact was detected when this method was employed in conjunction with air heating (AH). Each type of HDH desalination system has a different ratio of mass flow rates (MFRs) for the streams. This means that the efficiency of the system stays the same, no matter how the air moves through the system. The examination of temperature and relative humidity characteristics in the environment has indicated that this particular desalination unit is applicable in places characterized by both arid and humid conditions. Furthermore, in both air and water heating modes, it has been observed that the system employing SOA circulation has superior efficiency when the environment temperature is elevated. In the context of water and/or air heating, when a specific value is assigned to the MFR ratio of the two streams, modifying the mode of air circulation does not have an impact on the overall efficiency of the system. It is shown in this article for HDH with air heater the highest GOR is attained at either FCR = 1 or FCR = 0, depending on the operational temperature of the system. Also The system clearly works at its most efficient (GOR = 3.4) when it's in a Semi-open-air mode (FRC = 0.77) and the temperature is 50 °C. On the other hand, the system efficiency is 2.94 when the air exchange system is closed (FRC = 1). In the same way, the overall efficiency is 2.88 if the air flow is open (FRC = 0).

Improving Nickel Recovery in Froth Flotation by Purifying Concentrators Process Water Using Dissolved Air Flotation

The pressure for saving water by closing the water loops in mineral processing is increasing continuously. The drivers for higher recirculating rates include water scarcity in dry areas, environmental legislation that is becoming stricter in most countries, limitations set for wet tailings management and the increased demands for social licenses to operate. At the same time, to make mineral processing sustainable, the recovery of valuable minerals should be maximized. This leads for a need to close the process water circulation. To see the effect of closed water circulation on metallurgical performance, flotation tests were carried out with nickel concentrate thickener overflow water before and after the process of water purification by dissolved air flotation (DAF). Both total nickel recovery and concentrate grade in laboratory scale flotation tests to the Ni rougher-scavenger concentrate increased after DAF treatment. Chemical and mineralogical characterizations revealed that after DAF treatment, the process water contained fewer metal hydroxides and less fine-grained silicate mineral particles, which is most likely the reason for the improvement in the nickel flotation performance. Based on the feasibility study, improved nickel recovery by DAF treatment of process water can bring economic benefits at a concentrator plant.

Флотационное обогащение вольфрамовых руд в условиях замкнутого водооборота

The technological processes of enrichment are based on the consumption of a large amount of water from ore processing to the production of finished products. Water is an integral participant in enrichment, and its quality directly affects the level of extraction of the useful component and the quality of the products obtained during the enrichment process. One of the main socio-economic problems is the conservation of water resources and the reduction of environmental pollution. The solution to this problem is to reduce the consumption of fresh water in technological processes and increase the degree of water turnover at industrial enterprises. The object of the study is the process of flotation enrichment of relatively poor tungsten ore, with an initial content of a valuable component of 0.35–0.42 %. The purpose of the study is to search for new technological solutions in conditions of closed water circulation to reduce the consumption of fresh water and ensure a satisfactory level of extraction and quality of final products. Research objectives are the following: selection of the optimal flotation regime in conditions of a closed water circulation, localization of the area of impurity concentrations and determination of the maximum concentrations of components at which their effect on extraction is within acceptable limits, establishment of the necessary conditioning modes. The significance of the research lies in the need to find new technological solutions in a closed water cycle to reduce the consumption of fresh water and ensure a satisfactory level of extraction and quality of the final products. This article examines the relevance of the problem arising during the processing of tungsten calcium-containing ores in the conditions of water circulation. According to theoretical and experimental studies, it was found that without pre-conditioning of recycled water, the technological indicators of enrichment are significantly reduced, so, for example, the extraction of a valuable component in a closed water cycle is reduced from 80 to 40 %. This is due to the accumulation of a significant amount of carbonates and silicates in the recycled water. These indicators do not meet the requirements and are the basis for the search for new technological solutions. Based on this, a three-stage experiment was conducted, which allowed determining the maximum concentrations of harmful impurities. It is revealed that the maximum concentration of silicates depends on the carbonate background of the waters. The obtained data of experimental studies on the pre-conditioning of circulating waters satisfy the required qualitative and quantitative indicators. Two methods of conditioning have been developed – chemical and physico-chemical.

Promising technologies for bioremediation of wastewater from gold mining enterprises in Uzbekistan

The ever-increasing volumes of gold mining in the Republic of Uzbekistan requires an increase in the cost of water resources. However, the subdivisions of the Navoi MMC are located in the arid, lowwater areas with high (40–80 %) and extreme (more than 80 %) water shortages. Therefore, the problem of water supply, water disposal and improvement of the closed water circulation system with the use of innovative biotechnological solutions is acute for the enterprise. The purpose of this work is to summarize current data on the use of wastewater bioremediation technologies at mining enterprises and to assess the prospects for using this technology by Navoi Mining and Metallurgical Company. The article summarizes the data on the use of bioremediation at mining enterprises in Russia and other countries and data obtained from our own experimental studies of the cleansing functions of plants in Uzbekistan. These studies were carried out under the laboratory modeling conditions using wastewater from tailing ponds GMZ-2 and GMZ-3 NMMC. The cleansing functions of the plants of the Zarafshan river valley were studied: eichornia, pistia, azoles and duckweed. It was found that eichornia has the highest cleansing potential: due to the high activity of the cyanidutilizing enzyme beta-cyanoalanine synthase, it accumulates metals and metabolizes cyanides. Pistia and azola have proven to be tolerant to high salinity levels and need to be adapted by adding organic matter, including sheep manure. The next stage is semi-industrial testing in a tailing dump and development of technical regulations.

Methodology of Organization of Closed Water Circulation of Enterprises for the Production of Extraction of Phosphoric Acid and Mineral Fertilizers

Methodology of Organization of Closed Water Circulation of Enterprises for the Production of Extraction of Phosphoric Acid and Mineral Fertilizers

Source Rock Potential of Nampol Formation Sumbermanjing Area, Malang, East Java, Indonesia Based on Geochemistry Analysis of the Selected Sample

Nampol Formation of the Southern Mountains of eastern Java (Indonesia) has a distribution from its type location in Pacitan to the South Malang area. In the research area, this formation consists of clastic limestone with black shale inserts, claystone, siltstone, carbonate sandstone and claystone which are interpreted to be deposited in a restricted platform interior environment with closed water circulation. A total of three samples were analyzed to evaluate the organic matter content, kerogen type, thermal maturity, and hydrocarbon generating potential. Samples were taken from clastic carbonate deposits of the Nampol Formation. Based on the results of geochemical analysis, the three samples from the Nampol Formation have a TOC content of 3.48 - 26.18 wt% and possess good to excellent hydrocarbon generating potential. Hydrogen Index (HI) values for the studied samples ranged from 43 to 86 mg HC/g TOC and S1+S2 results ranged from 1.52 to 19.55 mg HC/g rock, indicating that the sample has the potential to produce gas. All three samples were dominated by Type III kerogen and were thus considered gas prone based on the HI vs. Tmax diagrams. The three samples were categorized as thermally immature based on Tmax pyrolysis analysis and Vitrinite Refl ectance (VR) values in the range of 0.44 to 0.46 % Ro. Based on the results obtained, the black shale and coal in the Nampol Formation has the capability to generate hydrocarbon but are considered as an immature source rock that can be predicted to produce gas at its peak maturity.

Инвестиционный проект создания замкнутых водооборотных циклов на промышленном предприятии

Due to the considerable costs involved in industrial wastewater treatment, the introduction of open (low-discharge) and closed water circulation systems is the most sensible way to prevent environmen-tal pollution at industrial companies. Since the level of circulating water treatment can be much lower than that required for discharge into a water body, the installation of closed water circulation systems can achieve both the economic and total effects of environmental protection. Despite the seemingly obvious advantages of this approach, it requires a serious feasibility analysis. The life cycle costs of a construction project can be estimated according to GOST R 58785-2019 Water Quality. Life Cycle Cost Estimation for Efficient Operation of Water Supply and Sanitation Systems and Facilities. However, at the initial (pre-project) stage, the analysis can be based on benchmarks. Large industrial companies make extensive use of foreign estimation methods. The paper presents the results of a feasibility analysis obtained using different methods to justify investments in the reconstruction of wa-ter treatment facilities at an oil refinery.

Depositional Environment of Nampol Formation and Its Implications as Potential Source Rocks in the Sumbermanjing Area, South Malang

The decline in oil and gas production inevitably forces explorationists to be more creative in finding new potential reserves. Nampol Formation is expected to have the potential to become hydrocarbon source rocks due to their organic matter content. However, the depositional environment of Nampol Formation has not been thoroughly researched. The focus of this research is to reveal the depositional environment of Nampol Formation that may lead to a suitable condition for the deposition of potential source rocks layers. Detailed geological mapping in several selected traverses and micropaleontological analysis was carried out to determine lithological characteristics and depositional environment of Nampol Formation. The microfacies approach was also used to determine the carbonate facies zone of this unit. Source rock samples taken from outcrops on the surface then were analysed to evaluate organic matter content, type of kerogen thermal maturity, and its potential to produce hydrocarbons. The Nampol clastic limestone unit in the study area is composed of clastic limestone with intercalation of black shale, claystone, siltstone, sandstone and calcareous claystone. The microfacies approach shows that the wackestone and mudstone belong to the SMF 15-M (Ooid wackestone) and SMF 23 (Non-fossiliferous mudstone) which can be interpreted belong to Facies Zone (FZ) 8 in the Flügel carbonate facies model (2004). This zone is located in the Restricted interior platform or platform environment with closed water circulation which is situated behind the barrier reef (back reef). Based on the results of geochemical analysis, source rock samples from Nampol Formation can be considered as a gas prone source rock, with type III kerogen, total organic content ranging from 3.48 – 26.18 wt%, po-sess the potential to produce

Purification of concentrated waste water of pcb production from copper ions

In modern conditions, it is important to create a comprehensive technology for processing wastewater containing copper compounds, with the disposal of precious metals, the organization of circulating water supply of the enterprise and obtaining safe for disposal sludge. Methods of sewage treatment of galvanic productions are considered.
 The results of experimental studies of the process of copper extraction from water by cementation on iron powder particles under static conditions are presented. The technological scheme of the reactor-cementator is given. The influence of various factors on the process of copper cementation – pH, concentration and ratio of iron and copper in the reaction mixture, contact time were studied. The time at which the greatest rate of change of residual copper concentration is observed is determined. The influence of the pH value of the cementation process was also determined. As a result of the obtained data, it is concluded that the concentration of hydrogen ions in the solution affects the course of the contact exchange reaction. The higher the acidity of the solution, the higher the recovery rate of copper. Promising directions for the creation of closed water circulation systems in the process of copper wastewater treatment are outlined.

Digital transformation model based on the digital twin concept for intensive aquaculture production using closed water circulation technology

The article discusses the complex digital transformation problem for the functioning aqua-biotechnological industrial company. The structure of the information model and digital twin for such objects is identified and described. The results of a comprehensive engineering and economic inspection of the state of the biotechnological, engineering, and economic system from the point of view of digital transformation are described. A conceptual scheme of the enterprise functioning based on the results of digital transformation is presented. The target effects of modernization and reconstruction of the existing biotechnological enterprise based on the end-to-end digital technologies of the fourth industrial revolution are formulated.

Ensuring environmental cleanliness and technosphere safety of electrochemical production

The article discusses the possibility of reducing the volume of wastewater from electrochemical shops that produce metal coating by electrolysis. Due to the complexity of wastewater treatment from an entire enterprise, the possibility of local return of valuable components to the very process in which they were lost is being considered. Possible ways of returning metal ions that have entered the wastewater back into the technological cycle are shown. The software for calculating the necessary equipment for the implementation of the most closed water circulation cycle is proposed. The author’s software greatly simplifies the choice of the type of flushing and makes it possible to choose the best option for performing the necessary actions. It is possible to combine different types of washing baths and traps not only for environmental reasons, but also for economic reasons.

Experimental research of parameters of industrial waters of canning plant and bakery. Analysis of treatment technologies

One of the industries that uses large amounts of water is the food industry. Industrial, domestic managers of the production process stand out with it and enter the environment surrounded by contaminated effluents. Their main feature is the high content of dissolved organic matter and nitrogen. You can also create wall water to create aggregate-resistant colloids, which include animal and vegetable fats, proteins, starch, sugar, as well as salts, carbohydrates, dyes, thickeners, preservatives. As a result of the technology of treatment of such industrial effluents, is a combination of different technologies and methods of treatment and the creation of several units depending on the parameters of wastewater. The purpose of our work is: 1) Analysis of physical and chemical indicators of industrial waters of food industry enterprises, monitoring of their impact on the environment; 2) to outline perspective directions of technologies of industrial water purification and creation of closed water circulation systems.

Beneficiation of recycled process water at DRDGOLD's ERGO plant, and its effect on gold recovery

SYNOPSIS To conserve fresh water resources and comply with environmental regulations, DRDGOLD, a South African gold producer re-treating surface tailings, has transitioned to a fully closed water circulation system. Consequently, the accumulation of contaminants, as well as addition of reagents, has led to changes in water composition that have compromised leach performance and overall gold recovery. A two-sample t-test confirmed a significant difference in gold recoveries between the use of Rand Water, which was used as a benchmark, and untreated process water. Atomic absorption analysis of ERGO's process water, confirmed the presence of iron, nickel, zinc, and manganese. A study of the effect of the identified contaminants on gold recovery showed that iron, nickel, and zinc have the largest negative effect on gold recovery, with iron and nickel being more detrimental than zinc. Sulphates were shown to have a possible passivation effect, which also influenced gold recoveries, although to a lesser extent than the heavy metals. Calcium, when present in excess, had a positive influence on gold recovery indicating the possible formation of a calcium aurocyanide complex. Lime softening successfully reduced the heavy metal and sulphate concentrations, and the gold recoveries obtained with the treated process water were similar to those as achieved with Rand Water. Keywords: gold tailings, re-processing, water quality, gold recovery.

Research Treatment Studies for Cleanable Waste Water for Cleaning Pipes


 
 
 Currently, many methods of treating waste water are known using various lubricating coolant compositions, but there is no universal treatment method. The most suitable ways of reducing the harmful impact of waste water in the metallurgical industry on the water environment are 1) the local treatment of waste water of various compositions, 2) the removal or reduction of the total amount of waste treatment liquid emissions as a result of their regeneration, and 3) reuse of treated waste water in closed water circulation systems and technical water supply to enterprises. During production of bimetallic finned tubes by cold deformation method, alkaline cleaning solutions are used to clean the surface from lubricating-cooling liquid. As a result, there is a need to dispose of spent liquids. The spent detergent solution is a three-phase emulsion. The upper layer is oil-oil products, medium liquid with increased PH index, and aluminates precipitate. A spent emulsion, i.e. an end-of-life emulsion that has lost its functional and operational properties, needs to be decomposed and disposed of.
 Keywords: finned bimetallic tube, air cooler, lubricating coolant, oil – emulsion
 
 

Sodium butyrate improves the performance of juvenile tilapia, Oreochromis niloticus (Linneaus, 1758)

In order to evaluate the effect of sodium butyrate on the performance of juvenile tilapia 400 fish (28.55 ± 1.55 g) were used, distributed randomly in 20 tanks (250 L) connected in a closed water circulation system. For 55 days, five levels of sodium butyrate (0, 0.5, 1.0, 1.5 and 2.0 g kg-1) were tested, with each experimental unit represented by 20 fish. To evaluate the treatments, the zootechnical performance, the hepatosomatic index, the viscerosomatic relationship, the centesimal composition of the fish, the hematology and the histology of the intestine were analyzed. Significant differences were observed with quadratic behavior for fish weight gain and specific growth factor, with 1.21 g kg-1 being the best result found for weight gain, while for growth factor 1.13 g kg-1 of organic acid. The feed conversion and the viscerosomatic relationship showed linear behavior, reducing the values ​​in relation to the increase in the level of sodium butyrate. In the hematological analysis, triglyceride levels showed a significant difference for the treatment with 0.5 g kg-1, which was 190.75 mg dl-1. In the histological analysis of the intestines and fish composition, there was no significant difference between treatments. The evaluated data demonstrate an effective action of sodium butyrate with the best result for fish performance at the level of 1.21 g kg-1.

Dissolution Test Protocol for Estimating Water Quality Changes in Minerals Processing Plants Operating With Closed Water Circulation

To save freshwater resources and comply with environmental regulations, minerals processing operations are transitioning to partially or fully closed water circulation. However, the accumulation of electrolytes and the addition of reagents lead to changes in water composition and may compromise flotation performance and plant maintenance. As a consequence, costly modifications are often required to cope with these challenges. Therefore, knowledge about water quality variation owing to closed water circulation and its potential effect on the flotation performance is crucial. The experimental methodology presented in this paper targeted three main objectives: (1) predicting the tendency of the accumulation of elements and compounds into the process water during comminution, flotation, and storage in tailings facilities; (2) establishing a relationship between laboratory results and plant historical water quality data; and (3) predicting the potential effect of recycling water on flotation performance. The results obtained with Boliden Kevitsa ore showed a good correlation between the water matrix of the actual process water on-site and that obtained in the ore dissolution tests done in the laboratory. The final water composition came close to the process water in terms of major elements and some of the minor elements. Additionally, the work presented in this paper demonstrated that a dissolution loop allowed us to predict the potential impact of the recycling water on the ore flotability. This methodology could serve as an aid for predicting water quality matrix variation and designing closed water circulation systems at existing and new plants.

The use of anionic flocculant in water treatment for flotation of apatite-nepheline ores

Currently, an urgent problem is the improvement of methods for purification of industrial water from concentrates of suspended particles and water-soluble impurities using polyacrylamide flocculants. By studying the adsorption processes from aqueous solutions of H and OH ions, the acid-base properties of the surface of the solid phase of the most contaminated technological product have been analyzed, i. e. discharge of the thickener of apatite concentrate, the mineral composition of which is 90 % represented by apatite. The influence of reagents present in the processing technology (fatty acid collector, iron sulfate) on the quantitative ratio of acid-base centers on the surface of apatite has been evaluated. It has been shown that the interaction of these reagents with the mineral creates prerequisites for greater efficiency of the anion-type flocculant. In order to determine the conditions under which flocculants of different types are in the maximally ionized state, studies have been carried out to change the viscosity of the polyelectrolyte solution at different pH values. The position of the isionic point for samples of cationic and anionic flocculants in the presence of reagents used in apatite flotation and dehydration of apatite concentrate has been studied as well. Studies on model and real suspensions in recycled water for a wide range of cationic and anionic flocculants have been performed. Kinetic and concentration dependencies of flocculating capacity of analyzed reagents have been determined; the experiments have confirmed the more efficient operation of anionic-type reagents. The search for the most effective reagents will make it possible to provide optimal water values for the content of suspended particles and hardness cations when introducing closed water circulation technology.

The influence of the electromagnetic field on the electric properties of water

<p>This paper presents an experimental study to investigate the effect of using the electromagnetic field on the electric conductivity and dielectric properties of treated tap water by aqua 4 D system according to the time of exposition in a closed water circulation circuit. There is a portion where there is an electromagnetic field obtained by the electromagnetic device. This work includes tap water circulation in the region of the electromagnetic field for 5 min, 10, 15, 20 min. The dielectric and electrical properties were examined and analyzed using the technique impedance spectroscopy in the frequency range going from 0.1 Hz to 1 MHz.</p><p>To initiate the phenomena involving water after magnetization with the electromagnetic field. The results clearly show that the magnetic field reduces the dielectric constant and resistance of water and increase its electric conductivity. In this study, we also find that the electrical conductivity of magnetized water increases.</p>

Aquaculture of green sea urchin in the Barents Sea: a brief review of Russian studies

AbstractGonads of the green sea urchin (Strongylocentrotus droebachiensis) containing valuable carotenoids, polyunsaturated fatty acids, phospholipids and sulphated fucans are in great demand from the expanding market. In Russian waters of the Barents Sea, only a few sites are suitable for commercial harvesting and thus the development of green sea urchin farming in this region. Our review presents a short survey of Russian literature on biological aspects and rearing methods of green sea urchins in the Barents Sea. In the 1980s, spawning induction and larval culture experiments were undertaken to obtain larvae of S. droebachiensis. Later studies were undertaken to test optimal rations and conditions for gonad enhancement of adult sea urchins in sea cages and closed systems. Gonadal growth was higher and faster in sea urchins reared under controlled conditions in closed water circulation tanks compared with sea cages. Regular feeding of cultured animals provided them better gonadal growth than in wild sea urchins irrespective of food items. Algal diets showed a lower level of gonad yield compared with mixed diets (algae + squid, algae + fish), fish diets and prepared diets (artificial feed based on fish skin). The coast of the Kola Peninsula has a good potential for the development of the green sea urchin farming but several financial, socio‐economic, logistic and management problems must be solved before this process starts.