Water Processing Plant Research Articles

Multimode system condition monitoring using sparsity reconstruction for quality control

<p>In this paper, we introduce an improved multivariate statistical monitoring method based on the stacked sparse autoencoder (SSAE). Our contribution focuses on the choice of the SSAE model based on neural networks to solve diagnostic problems of complex systems. In order to monitor the process performance, the squared prediction error (SPE) chart is linked with nonparametric adaptive confidence bounds which arise from the kernel density estimation to minimize erroneous alerts. Then, faults are localized using two methods: contribution plots and sensor validity index (SVI). The results are obtained from experiments and real data from a drinkable water processing plant, demonstrating how the applied technique is performed. The simulation results of the SSAE model show a better ability to detect and identify sensor failures.</p>

Influence of Water Quality on Sulphide Ore Oxidation and Speciation of Sulphur Anions during Autogenous Milling

Earlier studies at the Kevitsa Cu-Ni concentrator plant have indicated that seasonal variations of the properties of the process water affect the oxidation of the surface of the minerals, and further, the pentlandite flotation performance. However, it is not clear whether the differences in flotation performance are solely due to changes in the mineral surface oxidation, and/or also due to surface oxidation-induced changes in the aqueous phase of the pulp. This paper investigates the effects of the mineral surface oxidation of Kevitsa Cu-Ni ore on the properties of the aqueous phase of the slurry. A systematic study was formulated to monitor the surface oxidation related changes in the mill circuit of the Kevitsa concentrator plant. The study was timed to coincide with a seasonally observed drop in the concentrator plant’s flotation performance, which happens during the summer months (June, July, and August). Both physicochemical parameters, as well as sulphur oxyanions in the plant process water, mill discharge, and hydrocyclone overflows were monitored. Also, the bubble size in selected rougher and cleaner cells was monitored. The results show that season-related changes in mineral surface oxidation cause clear differences in the aqueous phase chemistry of the mill circuit. The increased concentration of reduced sulphur species in the mill discharge is an indication of extensive oxidation of the ore during milling. Also, the bubble size of the flotation cells reacts to the observed seasonal change. The findings of the study confirm that the consequences expected, based on the theory of mineral surface oxidation, are observable downstream in the aqueous phase of the milling circuit. Based on these results, it is not yet possible to say whether the poor flotation performance is caused solely by the oxidation of the mineral surface or also by the properties of the aqueous phase of the slurry after milling. However, the results show that the plant needs both to find ways to limit oxidation rates in the summer, and to consider installing a more robust frother, capable of maintaining efficacy during the warm season. The findings of this study may help the plant to develop ways to enable a timely response to changes in the recycled process water quality, to prevent harmful impacts on pentlandite flotation. The former could be achieved by lowering the temperature of the process water and flotation air, whereas the latter could mean using a different frother.

Impact of Recycled Process Water on Electrochemical Reactivity of Sulphide Ore

The Kevitsa Cu–Ni sequential flotation process is characterised by poor nickel recovery during summer periods (May–September). Evidently, the process water matrix in summer is different from that in other seasons; however, the Cu flotation performance is scarcely affected by the changes in the water matrix across the seasons. Increasingly different process water quality was generated through a grinding-and-dissolution protocol and its impact on the electrochemical reactivity of sulphide ore was studied. The main objective of this approach was to mimic the increasingly different quality of plant process water emanating from a closed-process water loop. Dissolved oxygen demand tests were conducted on the Kevitsa ore using water of varying quality from dissolution loops. The effect of the temperature and fine grind on the oxidation rates was also investigated. The study was coupled with EDTA metal ion extraction and xanthate adsorption tests. These showed that the number of dissolution loops, which has an impact on water quality, has a direct impact on the rate of oxidation of the ore. A fine grind and high temperature both increase the oxidation rates of the ore. The Kevitsa ore is most reactive in the first 10–20 min after milling. Furthermore, oxidation rates are also driven by the amount of pyrrhotite in the ore, with chalcopyrite being the least reactive, as indicated by the EDTA data. Xanthate adsorption is impacted by the water quality and fine grind. The combined effect of water quality, temperature and fine grind is expected to influence the flotation behaviour of sulphide minerals. The poor nickel recovery of the Kevitsa ore during the summer period is attributable to the unfavourable process water quality, which accelerates the oxidation of the ore during the summer period.

Origin, transport and ecological risk assessment of illicit drugs in the environment – A review

Illicit drugs are a novel group of emerging pollutants. A growing global environmental load and ecological risk is created by the ongoing release of these toxins into the environment. Conventional water processing plants fail to completely remove drugs of abuse from both surface water and wastewater. The origin, environmental fate and ecological repercussions of illicit drugs, despite their detection in surface waterways around the world, are not well understood. In this review, illicit drug detections in potable water, surface water and wastewater globally have been studied during the past 15 years in order to establish a baseline for future years. The most common drugs with abuse potential detected in different sources of potable and surface water were methadone (0.12–22.7 ng/L), cocaine (0.05–506.6 ng/L), benzoylecgonine (0.07–1019 ng/L), amphetamine (1.4–342.6 ng/L), and codeine (0.002–42 ng/L). The bulk of research only looked at a small number of drugs of abuse, indicating that despite widespread use, a large spectrum of these intoxicants has yet to be detected. This review focuses on the origin of illicit drug contaminants in water bodies, air, and soil, their persistence in the environment, and the typical concentrations at which they occur in the environment. The impact of these drugs on aquatic organisms like Elliptio complanata mussels, crayfish and zebrafish has also been reviewed.

Analysis of corrosion behaviour of carbon steel in a Qatari GTL plant process water

Internal Corrosion in tubing, piping, and process system is a huge challenge to the oil and gas facilities. Severe corrosion problems in the carbon steel pipelines are caused by the high corrosive produced water, leading to significant threats to the humans’ safety, and operation quality, and causing economic losses. In this study, the effect of the process water from the Qatar Shell GTL plant on the corrosion of SAE-1040 carbon steel was studied by using electrochemical measurements. The electrochemical measurement was performed utilizing electrical impendence spectroscopy (EIS) and Potentiodynamic polarization techniques. The corrosion behavior of the metal was tested at a variety of temperatures between 293K and 333K and different immersed times up to 3 h. It is reported that the corrosion rate of the carbon steel metal increased as the immersed period and the temperature increased. The behavior was attributed to the presence of cracks, holes, and pitting observed on the corroded steel surface as the immersion time and temperature increased. Scanning Electron Microscopic (SEM), X-ray Diffraction (XRD), Energy-dispersive X-ray (EDX), and X-ray Photoelectron Spectroscopy (XPS) tests were employed to study the surface of the corroded metal samples. The analysis of the corrosion products confirmed the formation of iron oxide (Fe2O3) as the main corrosion product.

Ізраїльський досвід післявоєнного відновлення економіки

Objective. The main objective of this article was to study the Israeli experience of post-war economic reconstruction and to define the factors effecting the growth and development of the economy of Israel. Methods. We used such general and specific methods as comparison, analysis, synthesis, graphic method and grouping in order to gain this objective. Results. As a result of this research we defined the main indicators of economic development of Israel and its position in world ratings. We also defined the main indicators of development of Israel as a state, among which are international support, issue of government bonds, reparation from Germany, and development of the New Economic policy, establishment of the Israeli Military Force culture and inflow of human resources. Launching of major infrastructure projects played a significant role in economic recovery, such as water supply system construction, sea ports and processing plants. Moreover, state supported agriculture and light industry. The economy of Israel is highly developed due to support to research and development achievements made by scientists, thus, it is based on gaining new knowledge and its practical implementation. The basis for Israel’s economic miracle is science, the development and implementation of new technologies with their further adaption for real manufacturing. Israel’s experience is a valuable example of post-war reconstruction of a country and the way to bring the country out of ruins. It is worth taking Israeli experience into account while developing Ukraine’s Marshall Plan when it goes about taxation, state production support, human capital accumulation, development of innovations and their implementation into processing industry. Scientific novelty. In the research the authors proved that the phenomenon of Israel’s economic miracle is unique and its experience is a positive example of how to make the economy innovative out of nothing. Practical significance. The research defined the factors effecting the establishment of the economy of Israel. These factors may be used in the Ukrainian reality, while developing the recovery plan. Key words: economy competitiveness, innovative economy, technology and innovation, post-war reconstruction, international experience, global economy, development.

A mathematical model for open pit mine production scheduling with Grade Engineering® and stockpiling

This paper presents the development and implementation of an innovative mixed integer programming based mathematical model for an open pit mining operation with Grade Engineering framework. Grade Engineering comprises a range of coarse-separation based pre-processing techniques that separate the desirable (i.e. high-grade) and undesirable (i.e. low-grade or uneconomic) materials and ensure the delivery of only selected quantity of high quality (or high-grade) material to energy, water, and cost-intensive processing plant. The model maximizes the net present value under a range of operational and processing constraints. Given that the proposed model is computationally complex, the authors employ a data pre-processing procedure and then evaluate the performance of the model at several practical instances using computation time, optimality gap, and the net present value as valid measures. In addition, a comparison of the proposed and traditional (without Grade Engineering) models reflects that the proposed model outperforms the traditional formulation.

Mechanisms of thermal treatment on two dominant copepod species in O3/BAC processing of drinking water

Phyllodiaptomus tunguidus and Heliodiaptomus falxus are dominant copepods species in drinking water processing plants in southern China. With a potential penetration risk, the breeding and leakage of copepods are drawing more and more attention in recent years. The current study provided a thermal treatment method to control copepods and their eggs. Results showed that: (1) the immediate death rates of P. tunguidus and H. falxus after heated to 34–40 °C for 5 min are positively correlated to the treatment temperatures (P < 0.01), and all individuals of the both species were eliminated after heated at 40 °C for 5 min; (2) overall hatching rates of P. tunguidus eggs were negatively correlated with treatment temperatures (P < 0.01) between 39–45 °C, with zero percent hatched after treatment at 45 °C for 5 min; (3) hatching rates of H. falxus were negatively correlated with treatment temperatures (P < 0.01) between 37–41 °C, with no nauplii hatched when treated at 41 °C for 5 min; (4) paraffin section histological examination indicated that thermal treatment caused severe damage to internal organs and egg structure. Finally, based on the experimental data, the application of the thermal treatment method was discussed in ozonation combined with biological activated carbon (O3/BAC) processing of drink water treatment.

Treatment of iron ore beneficiation plant process water by electrocoagulation

Process water collected from the iron ore beneficiation plant was treated by electrocoagulation (EC) process to make it suitable for reuse or safe for discharge. Experimental studies were carried out towards efficient removal of the various metal ions such as iron (Fe), chromium (Cr), copper (Cu), zinc (Zn), manganese (Mn), lead (Pb), aluminum (Al) from process water along with monitoring of total dissolved solids (TDS), turbidity, conductivity, salinity. The influence of various operating parameters of EC, such as electrode material, electrode configuration, current density, inter-electrode distance, and solution conductivity, were explored for effective treatment of process water. Experimental results showed that aluminum electrodes at monopolar mode with a current density of 68.50 A/m2, an inter-electrode distance of 1 cm, and solution conductivity of 1033 µS/cm were the ideal operating conditions to get treated water with a removal efficiency of 99.95%, 99.46%, 99.33%, 97.99%, 73.44% for Fe, Cr, Pb, Mn, and Cu ions respectively after 60 min of EC with electric energy consumption of 3.93 kWh/m3 and operating cost of 0.6115 US$/m3. X Ray Diffraction analysis of EC generated sludge confirmed the exclusion of major elements like Fe, Cr, Cu, Zn, Mn, Pb, Al as well as trace elements such as Nickel, Cobalt, Magnesium, Titanium, Vanadium, Zinc, Neodymium, Samarium, Yttrium, etc. from process water.

First insights to the microbial communities in the plant process water of the multi-metal Kevitsa mine

Metallurgical processes demand large quantities of water. However, in many locations, water is becoming scarce and process water recycling is needed. Closing water loops can be challenging due to build-up of flotation chemicals, metal ions and microorganisms in the recycled water affecting the flotation performance. Here, we have characterized the microbial communities over a 2-month period in different locations of the multi-metal Kevitsa mine in Northern Finland, by microbiome sequencing, enumeration of bacteria, archaea and fungi by qPCR, and cultivation. The microbial communities showed high diversity, but were dominated by Alpha- and Gammaproteobacteria. In addition, various fungal taxa were detected, whereas the archaeal taxa were only sparsely detected from the sequence data. The number of bacterial 16S rRNA gene copies in Process water and Ni thickener overflow varied between 0.5–3.3 × 105 mL−1, whereas the Flotation tailings showed two orders of magnitude lower amounts. Fungi were present at 3.0 × 102–8.1 × 104 5.8S rRNA gene copies mL−1 in all samples, while the number of archaea fluctuated between 8.8 × 101–3.2 × 105 16S rRNA gene copies mL−1. The number of all microbial groups were generally lower in September than in August. When tested on 8 different cultivation media, the microorganisms generally responded positively to organic carbon, and were also shown to oxidize thiosulfate, which may indicate that build-up of organic flotation chemicals and sulfur species from the ore may cause the microbial numbers to increase. This study is part of the H2020 ITERAMS project (Grant agreement# 730480), which strives to improve the recycling of water and minimize the environmental impact of mines.

Analogous Electrical Model of Water Processing Plant as a Tool to Study "The Real Problem" of Process Control

Analogous Electrical Model of Water Processing Plant as a Tool to Study "The Real Problem" of Process Control

Application of G-SERS for the efficient detection of toxic dye contaminants in textile effluents using gold/graphene oxide substrates

The upsurge of colored, hazardous dye pollutants has led to the excessive presence of carcinogens in the environment, thereby requiring a sensitive, rapid and facile detection method. In this study, graphene oxide mediated surface enhanced Raman scattering (G-SERS) based sensor was studied on gold/reduced-graphene oxide nanocomposites (Au/GO NCs). Typical absorptions at 261 nm and 531 nm observed in UV–visible spectroscopy, XRD peaks at 24°, 38.2°, 44.5°, 64.7°, and 77.6° along with the TEM images showed the formation of spherical Au nanoparticles incorporated rGO sheets. In this study, monoazo, diazo, triarylmethane, thyazine and xanthenes dyes were analyzed. Further, the predominant dye contaminant contributor: textile effluent (TE) collected from Erode, India was studied. From the G-SERS spectra it can be concluded that TE may me a mixture of azo, aryl and xanthenes dyes. Also the carcinogenic aromatic structures such as CN and CN were detected successfully. Synergistically, the electromagnetic enhancement from the hotspots and hot surfaces, chemical enhancement offered by rGO and effective fluorescence quenching observed result in well defined, enhanced G-SERS signals. This work suggests the feasibility of Au/GO NCs as an effective pollutant sensor in water processing and treatment plants for industrial effluents.

Analysis of ground vibration risk on mine infrastructures: integrating fuzzy slack-based measure model and failure effects analysis

Blasting operation is the main unit of ore production in open-pit mining cycle. Detonation energy is mostly released as ground vibration using Rayleigh waves that extensively damage nearby infrastructures within or outside of a mining area. This work introduces a new hybrid approach based on the integration of fuzzy failure mode and effects analysis with the fuzzy slack-based measure model form of data envelopment analysis; this approach prioritizes and analyzes ground vibration risks on open-pit infrastructures. The approach uses a special risk prioritization algorithm by failure mode and effects analysis and data envelopment analysis under fuzzy conditions. In the fuzzy slack-based measure part of the approach, α-level cut method is used to prepare the necessary data. An open-pit copper mine is exemplified to present the approach in detail and analyze ground vibration risk. Potential failure modes, consist of infrastructures and blasting sources, are specified on the map on the mine area. Results indicate that blasting at the point of 3 imposes the highest ground vibration risk on the industrial site located within the final pit limits. The failure modes of water treatment site, crusher, gas station, explosive storage, switchgear, thickener site, power station, and processing plant have other priorities.

Properties evaluation and fabrication of green clay reformulated from water sludge

Water sludge from Sungai Dua Penang fresh water processing plant has been successfully converted into functional pottery clay with improved physicochemical behavior and properties. Water sludge was generally made of kaolinite mineral that consisted of silica and alumina. At 7h of milling duration, water sludge demonstrated a narrow particle size distribution at the size range of 107–150µm. Water sludge owned a specific surface area of 27m2/g with 8.8nm (diameter) pore size and 0.05cm3/g pore volume. Plasticity of clay body increased when clay formulation involved fine particles, e.g. water sludge or bentonite, which promote water adsorption ability. Fine particles with large surface area and better compaction also explained the enhanced hardness of pottery clay. The incorporation of clay minerals such as bentonite and sodium silicate into the formulation has facilitated metals immobilization within the clay body. Final clay product has a terra cotta color and performed a uniform shrinkage without obvious fracture. The fabrication of pottery wares from water sludge with minimized metals leakage has not only higher reutilize value but also a cost effective green method for handling waste and environmental issues.

Nanotechnology and water purification: Indian know-how and challenges.

Water contamination being ubiquitous problem across the world. A significant strata of population worldwide are still struggling to get drinkable water. This demand to develop technologies to provide clean water at affordable price is unveiling the need of rigorous research in this area. There are several technologies available for removal of persistent as well as emerging pollutants from water. Nanotechnology-based technology are providing the promising solution because of its extraordinary characteristics like large surface area, low cost maintenance and reuse, etc. During the past decade, there is an advancement in the field of nanotechnology and diligent efforts of researchers in achieving milestones in developing nanosorbents, nanostructured catalytic membranes, efficient photo catalysts, bioactive nanoparticles and new filtration regime. This article gives an overview of nanotechnology applications in water purification in India with an attempt to ponder indigenous technologies for implementation. A bibliometric approach is applied to bring the indigenous technologies available. In addition, we discuss some challenges associated with the development of convincing material and building water processing plants for purification of the wastewater.

ELECTROMAGNETIC RESONANCE VIBROCAVITATOR

Резонансний електромагнітний віброкавітатор призначений для кавітаційного оброблення рідин на основі води. Ці кавітатори ефективні у використанні для очищення води басейнів аквапарків від біологічних забруднень, для покращення структури питної води. Резонансні електромагнітні віброкавітатори автори створили вперше, їх конструктивна будова захищена патентом на винахід. Конструкція цього вібраційного кавітатора доволі універсальна, що створює передумови для успішного використання її як для трубопроводів незначних перерізів у діапазоні від одного до трьох дюймів, так і для промислових труб водогонів діаметром до 250-300 мм. Особливо ефективним, на нашу думку, вібраційний кавітатор мав би виявитись для біологічного знезараження питної води. Простота його конструкції та обслуговування створюють передумови для вмонтовування кавітатора у трубопроводи перепомповування води в басейнах, аквапарках та водоймах громадського використання, де поряд із знезараженням води здійснюватиметься і її очищення. Внаслідок сплескування кавітаційних бульбашок тут утворюються активні хімічні речовини: гідроксильні радикали, озон, пероксид водню тощо. По суті, ця технологія є комбінованим способом очищувального впливу на воду. Основними вузлами цих кавітаторів є статор із електромагнітами, коливний якір із збурювачами кавітації та резонансна пружна система, що з'єднує якір із статором. Продуктивність кавітаційного оброблення води басейнів – 1,5-2,0 м3/год, ступінь очищення стоків молокопереробних підприємств – 97-98 % за продуктивності до 100 л/год. Продуктивність очищення стоків пивоваріння від дріжджів становить 200-250 дм3/год.

Evaluation and reutilization of water sludge from fresh water processing plant as a green clay substituent

Water sludge from a fresh water processing plant in Sungai Dua Penang was investigated from the aspects of physicochemical properties and its reutilization possibility. Morphology and size distribution of the water sludge were studied via field emission scanning electron microscopy and sieving method, respectively. The water sludge particles of irregular shapes and sizes exhibited a relatively large specific surface area of 27m2/g, pore size of 8.8nm and pore volume of 0.05cm3/g. Besides, the water sludge chemical composition comprised of major components such as silica (SiO2, 40.33wt%) and alumina (Al2O3, 31.84wt%), which are the basic content of soil. The presence of aluminium in water sludge justified the addition of coagulant during water processing process. 97.9% of the mineral phase in the water sludge was identified as kaolinite (Al2Si2O5) and quartz (SiO2) that showed beneficial mechanical properties in the sludge-based products, e.g. pottery clay. Whereas hematite phase (Fe2O3, 1.6%) in water sludge contributes to the reddish color of the final products after firing, which makes an ideal raw material for terra cotta. Application of the water sludge as an environmentally friendlier green clay was explored through the clay reformulation. In short, reutilization of water sludge to partially replace mineral clay for ceramic products have been successful and may be useful in solving environmental issues and waste management.

Studying bitumen–bubble interactions using atomic force microscopy

Processing of oil sands using water-based extraction processes requires selective aeration of liberated bitumen droplets to facilitate transport of aerated bitumen to the top of the slurry where it is recovered. Colloidal forces between bubble and bitumen or silica control the selective attachment of bitumen to air bubbles as desired. In this study, interaction forces between bubble and bitumen or silica were measured in various aqueous solutions using atomic force microscopy (AFM). The wettability of the silica particles was found to play a significant role in controlling bubble–silica interactions. There exists a long-range repulsive force and zero adhesion between air bubbles and hydrophilic silica spheres, in contrast to strong attractive force and large adhesion force between the air bubble and hydrophobic silica spheres. The results suggest the potential of unwanted aeration of hydrophobic solids, leading to a poor froth quality. Study on bitumen–bubble interaction shows that the types of surfactants have a great effect on the long-range interaction due to their adsorption on the bubble surface, which could cause the bubble surface either positively or negatively charged, leading to different electrostatic forces. In the plant process water or in the anionic surfactant solution, the bitumen-coated silica sphere could penetrate into the bubble to form a three-phase contact (TPC) line when the external loading force exceeds a threshold value.

English

&nbsp; This paper presents an electrical model for studying the process behaviour of a sachet water production plant. In this model, the mechanical components of the plant such as the connecting pipes, the water tanks and the water filter were represented by resistors, capacitors and an inductor, respectively. A state equation was developed as a mathematical model of the electrical circuit. In this equation, resistors, capacitors and inductor representing the restriction of the pipes, the capacity of the tanks and the filtration of the filter respectively, were used as variable parameters to generate the state variables of the state equation. This mathematical model was used to simulate the effects of varying the electrical parameters (and) on the state variables (&nbsp;and) representing the restriction of the connecting pipes, the water levels () in the water tanks and the filtration of the water filter, respectively. Insight into the response curves will indeed form the basis for studying the process control of the sachet water processing plant. &nbsp; Key words:&nbsp;Mathematical model, analogous system, state equation, control, modeling, simulation

Solvent extraction of uranium from saline leach liquors using DEHPA/Alamine 336 mixed reagent

The presence of chloride in sulphuric acid leach liquors has a negative impact on the solvent extraction process for the recovery of uranium using tertiary amine reagents, such as Alamine 336. This can increase operating costs, and limit the use of saline water as plant process water. This study is based on the use of a mixed solvent containing DEHPA (di-2-ethylhexylphosphoric acid) and Alamine 336, and examines the performance of this system for uranium recovery from an overall process perspective. It investigates the impact of chloride, sulphate and acidity on uranium extraction and discusses the selectivity of the mixed reagent for uranium over iron (III) in the context of loading and selective scrubbing. The study also presents results of sulphuric acid (5–8 M H2SO4) and alkali (1 M Na2CO3) stripping of uranium, and the need for addition of phase modifiers such as TBP (tributylphosphate), DBBP (dibutyl-butyl phosphonate) and TOPO (trioctyl phosphine oxide), to prevent third phase formation.