Seawater reverse osmosis membrane fouling causes in a full scale desalination plant; through the analysis of environmental issues: raw water quality

Background: Membrane clogging is one of the most important problem for desalination plant operators in Iran, therefore, this study was conducted to investigate the main causes of this problem using field analysis. Methods: In this study, six continuous membranes in a reverse osmosis (RO) pressure vessel under the 33-month service period (April 2017 to November 2019) were selected. The membranes were analyzed through visual evaluation of the outer and inner membrane surface, analyzing the damages and physical harms, oxidative stress tests, iron spot test, fouling chemical analysis using loss on ignition (LOI) tests, X-ray fluorescence (XRF), and Fourier-transform infrared (FTIR) spectroscopy. Results: Particle size distribution in raw seawater (EC = 55 000 μs/cm, turbidity = 11 NTU) was 66.4% smaller than 1 μ and 28.3% between 1 to 1.9 μm. Physical damages were not seen on the membranes but telescopic damages were observed which was due to membrane fouling. Removal efficiencies of turbidity and silt density index (SDI) were 84% and 18%, respectively. Membrane oxidation was also seen. Most of the sediments compositions on the membranes were SiO2, Al2O3, MgO, and Fe2O3. Biological fouling was detected on the membranes surface. Conclusion: Inaccurate use of chlorine neutralizer caused the residual chlorine to be present in the membrane entering water, which damaged the membrane. Accumulation of clogging agents on membrane surface showed malfunction of pretreatment function, therefore, revision of design and operation of units is necessary. Biological fouling is due to non-effective pre-chlorination of drinking water. Metallic compounds sedimentation on the membrane is due to improper use of anti-fouling chemicals. High SDI in the influent shows the need to change the cartridge filters. Keywords: Seawater, Drinking, Chlorides, Particle size, Chloride, Spectroscopy, Fourier transform infrared, Ira

Application of artificial intelligence techniques for predicting the flyrock, Sungun mine, Iran

Flyrock is known as one of the main problems in open pit mining operations. This phenomenon can threaten the safety of mine personnel, equipment and buildings around the mine area. One way to reduce the risk of accidents due to flyrock is to accurately predict that the safe area can be identified and also with proper design of the explosion pattern, the amount of flyrock can be greatly reduced. For this purpose, 14 effective parameters on flyrock have been selected in this paper i.e. burden, blasthole diameter, sub-drilling, number of blastholes, spacing, total length, amount of explosives and a number of other effective parameters, predicting the amount of flyrock in a case study, Songun mine, using linear multivariate regression (LMR) and artificial intelligence algorithms such as Gray Wolf Optimization algorithm (GWO), Moth-Flame Optimization algorithm (MFO), Whale Optimization Algorithm (WOA), Ant Lion Optimizer (ALO) and Multi-Verse Optimizer (MVO). Results showed that intelligent algorithms have better capabilities than linear regression method and finally method MVO showed the best performance for predicting flyrock. Moreover, the results of the sensitivity analysis show that the burden, ANFO, total rock blasted, total length and blast hole diameter are the most significant factors to determine flyrock, respectively, while dynamite has the lowest impact on flyrock generation.Peer ReviewedObjectius de Desenvolupament Sostenible::9 - Indústria, Innovació i InfraestructuraPostprint (published version

Modeling of causes and consequences of human error in mining processes design: A qualitative study

This research was funded by the Hamedan University of Medical Sciences and Health Services and grant number 140008257113.Peer ReviewedObjectius de Desenvolupament Sostenible::3 - Salut i BenestarObjectius de Desenvolupament Sostenible::8 - Treball Decent i Creixement EconòmicObjectius de Desenvolupament Sostenible::9 - Indústria, Innovació i InfraestructuraPostprint (published version

UTJECAJ IZLUŽIVANJA AMONIJEVA SULFATA NA ADSORPCIJU IONA RIJETKIH ZEMALJA I MEHANIČKA SVOJSTVA TLA

In-situ leaching (ISL) has gained prominence as a non-destructive method for rare earth element (REE) extraction, particularly in regions like China. However, concerns over the environmental impact and soil stability due to ISL activities have surfaced following a landslide incident. This article distills the essence of a comprehensive research endeavor that delves into the effects of ammonium sulfate ISL leaching, employing concentrations of 0.05M, 0.1M, and 0.5M, on soil mechanical properties. The study encompasses physicochemical, physical, and mechanical tests, unveiling substantial alterations in shear strength, cohesion, angle of internal friction, zeta potential, liquid limit, plastic limit, and plasticity index following leaching. XRF and XRD analyses reveal the presence of REEs and distinctive mineral phases in the soil samples. Overall, ISL induces a weakening of the soil, raising concerns about potential slope failures and emphasizing the need for a deeper understanding of ISL’s impact on soil properties in the context of REE mining.U pojedinim kineskim regijama terensko izluživanje postalo je važna nedestruktivna metoda za ekstrakciju elemenata rijetkih zemalja. Međutim, nakon incidenta s pojavom klizišta raste zabrinutost zbog utjecaja na okoliš i na stabilnost tla uslijed tih aktivnosti. Ovaj članak prikazuje bit opsežnoga istraživačkog pothvata koji istražuje učinke terenskoga izluživanja amonijeva sulfata, koristeći se koncentracijama od 0,05 M, 0,1 M i 0,5 M, na mehanička svojstva tla. Studija obuhvaća fizičko-kemijska, fizička i mehanička ispitivanja kojima se utvrđuju važne promjene u čvrstoći na smicanje, koheziji, kutu unutarnjega trenja, elektrokinetičkom (zeta) potencijalu, granicama plastičnosti i tečenja te indeksu plastičnosti nakon izluživanja. XRF i XRD analize otkrivaju prisutnost elemenata rijetkih zemalja i karakteristične mineralne faze u uzorcima tla. Općenito, terensko izluživanje izaziva slabljenje tla te izaziva zabrinutost zbog potencijalnih slomova na kosinama i naglašava potrebu za dubljim shvaćanjem utjecaja terenskoga izluživanja na svojstva tla u kontekstu rudarenja elemenata rijetkih zemalja

A Mimic Model Approach for Impact Assessment of Mining Activities on Sustainable Development Indicators

This study was supported by the Hamedan University of Medical Sciences and Health and ethical code IR.UMSHA.REC.1400.617. The study program was approved by the national committee for ethics in medical research (IR.UMSHA.REC.1400.617).Peer ReviewedObjectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats SosteniblesObjectius de Desenvolupament Sostenible::8 - Treball Decent i Creixement EconòmicObjectius de Desenvolupament Sostenible::13 - Acció per al ClimaPostprint (published version

Multi-criterion analysis of the most important aspects of the environmental pollution

Technological procedures for obtaining the useful mineral raw materials on the excavation site create the environmental pollution. This is manifested in several ways such as: blocking of land, degradation of soil and appearance the other forms of pollution (dust, gases, mineral water and noise, which affect the pollution of air, water, land, plants and human health). Consequently, in this paper, a multi-criterion analysis was carried out aiming to rank the all types of environmental pollution in order to identify the most difficult types of pollution. Also, the work presents the most important environmental protection measures, in accordance with the most severe types of pollution, and their ranking has been carried out with the aim of determining the most important measures. The AHP analysis was used for the multi-criterion analysi

Developing new models for flyrock distance assessment in open-pit mines

Peer ReviewedObjectius de Desenvolupament Sostenible::9 - Indústria, Innovació i InfraestructuraPostprint (published version

Causal analysis of safety risk perception of Iranian coal mining workers using Fuzzy Delphi and DEMATEL

Underground coal mines, one of the most dangerous work environments, have experienced accidents and disasters. One of the main reasons for those unsafe events is the workers’ poor understanding of the hazards and risks of working in this work environment. Therefore, the present study aims to identify factors affecting the safety risk perception of underground coal mine workers in Iran and investigate their cause-and-effect relationships. By reviewing the literature, 40 variables were identified in five categories: individual, organizational, environmental, task, and external factors. The identified variables were ranked according to the expert group’s opinion in the form of a fuzzy Delphi study regarding their effects on risk perception. In the next step, 23 variables were selected to investigate the cause-and-effect relationships using the DEMATEL method. The study’s findings showed that organizational factors and some individual factors play a fundamental role in workers’ risk perception. The variables of safety culture, safety management style, and safety attitude had the most significant impact, and the variables of personal protective equipment and risk aversion had the smallest impact on workers’ risk perception. The present study’s findings can be used as a guideline to provide effective solutions for managers and workers in improving safety risk perception, subsequently reducing unsafe behaviors and increasing the safety status of underground coal mines.This research was funded by the KASHAN University of Medical Sciences and Health Services and grant number 140008257113.Peer ReviewedObjectius de Desenvolupament Sostenible::8 - Treball Decent i Creixement EconòmicPostprint (published version

Ranking of the most important criteria for the selection of the mining method for non-stratified deposits

Selecting and planning of the mining method for non-stratified deposits is the most delicate and complex process on which the success of the mine depends. This procedure is basically a multi-criteria decision making problem in which the aim is to select the best mining method from many alternatives. The aim of this paper is to show the influence of many factors (criteria) in the selecting of the most suitable mining method and to determine their influence on this process. The eight groups of influencing factors, i.e. criteria, were taken into account-geometric data on the ore body, the mechanical characteristics of the massif, the ore reserves, the situation on the surface of the terrain, the workforce, the possible environmental hazards, the market conditions and the safe working conditions. The AHP method was used for ranking these criteria. The ranking was carried out by mining experts and managers of various underground mines in Serbia using the group decision method. The results obtained show a clear distinction between the individual criteria when selecting the best mining method. Furthermore, the results clearly show the importance of the ranking process in determining the most influential criteria in this very complex process