Desalination Waste Research Articles

Gypsum Binder With Increased Water Resistance Derived From Membrane Water Desalination Waste

ABSTRACTA method has been developed for separating a mixture of calcium, magnesium and sodium sulfates obtained through the interaction of sulfuric acid and waste from the water purification process generated by using membrane filters. The primary goal of this method is to extract gypsum and produce gypsum‐based binders. Patterns were identified regarding how various types, ratio and quantities of additives: blast furnace slag, granite screenings, portland cement, electric steel smelting slag affect the water‐gypsum ratio, strength properties, and water resistance of high‐strength gypsum binders. It was found that adding a single‐component additive specifically to enhance water resistance does not significantly impact these properties. Complex additives have been developed based on Portland cement, granulated blast furnace slag, electric furnace slag, expanded clay dust, and granite screenings of various fractions. These additives are designed to maximize the water resistance of high‐strength gypsum binder based on synthetic calcium sulfate dihydrate. As a result, the water resistance coefficient increased from 0.45 to 0.52. Additionally, a technological block diagram of the process has been proposed.

Organization of processes for complex mining and processing of mineral raw materials from coal mines in the context of the concept of sustainable development

Purpose. The research purpose is to form the principles and procedures for developing an organizational concept of complex mining of minerals from coal mines using the example of a promising model of transition of the PJSC “DTEK Pavlohradvuhillia” mines to multi-product production of clean drinking water, utilization of methane, secondary coal from rock dumps and slurry reservoirs, low-grade thermal energy of mine groundwater and associated raw materials from desalination waste. Methods. The instrumental basis of the research is the methodology of the process approach to organizing multi-product activities of an enterprise. In addition, an integrated approach is used, including an analysis of existing experience and available complex coal mining and processing technologies. Findings. The paper presents the research results of the prerequisites for the development of innovative technological solutions related to the integrated use of mineral raw materials formed in the process of coal mining and processing. It has been revealed that at the present stage the technological, environmental and economic aspects of such innovations have been sufficiently developed, while the organizational issues regarding the balanced interaction of multi-product production units have poorly been studied. The necessity has been substantiated, as well as the content and sequence of actions have been determined for the development of an organizational concept of complex mining and processing of mineral raw materials in the conditions of PJSC “DTEK Pavlohradvuhillia”. Originality. The principles and procedures for developing an organizational concept of a multi-product enterprise, formed in the research process, provide further development of a methodological basis for searching and substantiating innovative solutions for complex mining of mineral resources from coal mines. They can be used to assess the efficiency and identify weaknesses in current processes for mining and utilization of coal, thermal energy, methane gas, groundwater, dry residue chemicals from desalination and coal mining waste, and to analyse and make changes to improve performance and reduce costs. Practical implications. The proposed complex of organizational solutions based on the process approach tools to ensure the effective implementation of a promising production model for mining and processing of mineral resources in PJSC “DTEK Pavlohradvuhillia” coal mines provides an opportunity to predict the results and develop development strategies based on various scenarios, analyze the interaction of various factors and their influence on the results of the production complex functioning, while reducing costs for experiments and testing of various production technologies.

ЗАБЕЗПЕЧЕННЯ СТАЛОГО РОЗВИТКУ НА БАЗІ АНАЛІЗУ ТА ОЦІНКИ ХАРАКТЕРИСТИК ШАХТНИХ ВОД ЯК ДЖЕРЕЛ ВОДОПОСТАЧАННЯ ТА ОТРИМАННЯ ЦІННИХ РЕЧОВИН З ВІДХОДІВ ОПРІСНЕННЯ

Purpose. Rationale for the integrated use of the resource potential of coal-mining enterprises, which is aimed at obtaining technical and drinking water for their own production needs, local population and obtaining valuable substances from desalination waste. Methodology. Analysis of world experience, information about aquifer complexes in the Western Donbas mines, conducting chemical analyses of mine waters and salt mixtures obtained after using reverse osmosis products. Results. Based on the accumulated world experience in desalination of highly mineralized waters, it can be concluded that it is possible to effectively implement this experience at mining enterprises. Description of aquifer complexes has been given in detail using the example of the Zakhidno-Donbaska Mine of PJSC “DTEK Pavlohradvuhillia”, chemical analyses of water before and after discharge into settling ponds. A rational technological scheme for desalination, volumes of purified water obtained for drinking and technical water supply, as well as the quantitative and qualitative composition of the dry residue components of mine water desalination waste, and recommendations on possible use of products on the market have been determined. Scientific novelty. Analytical and laboratory studies have been conducted to determine the component composition of mine water desalination waste from Western Donbas coal-mining enterprises. It has been determined that the resulting salt product is a mixture of pure salts and valuable microcomponents, and the resulting distillate is fuel for the operation of hydrogen electrolyzers, which creates prerequisites for modern “green” hydrogen energy infrastructure. Practical significance. The qualitative and quantitative mine water parameters on complex use as an alternative source of water supply and obtaining related reverse osmosis products have been analyzed. The road services propose the consumption of the resulting salt products by municipal enterprises, and the dry distillation residue – to prevent dust. This approach allows solving not only the problem of desalination waste utilization, but also applying the separated valuable substances in the industrial market of food, medical, cosmetic, paint and varnish, chemical, as well as building materials, plastics and polymers production industries. Keywords: mine water, waste recycling, mineral resource, coal-mining enterprises.

RGO coated cotton fabric and thermoelectric module arrays for efficient solar desalination and electricity generation

This research employs rGO-coated fabric for desalination, harnesses solar heat for power generation via TEG modules, and produces emission-free hydrogen through seawater electrolysis, showcasing an in situ solution for desalination waste remediation.

Technoeconomic analysis of photoelectrochemical hydrogen production from desalination waste brine using concentrated solar flux

Co-generation of hydrogen with value-added by-products is a promising route for affordable low-carbon hydrogen. This work presents a system for and a technoeconomic analysis of hydrogen with the co-generation of chlorine and sodium hydroxide from waste brine. The system uses a conceptual triple-junction gallium arsenide (3-J GaAs)-based photoelectrochemical (PEC) reactor at high solar concentrations (50–500x). The base case of 200x solar concentration results in a solar-to-chemical (SCE) efficiency of 15% and a levelized cost of hydrogen (LCOH) production of $15.76/kgH2. Revenue from by-products ($45.36/kgH2) is critical for offsetting the operating costs, with sodium hydroxide constituting 64% of total by-product revenue. The sensitivity analysis showed that under favorable combinations of the key variables (sodium hydroxide price, waste brine pretreatment price, and PEC replacement lifetime) PEC hydrogen generation from waste brine would be viable and have prices reaching $0.78/kgH2.

A new concept for complex mining of mineral raw material resources from DTEK coal mines based on sustainable development and ESG strategy

Purpose. The research purpose is to develop a concept for complex mining of mineral resources from coal mines using the example of PJSC DTEK Pavlohradvuhillia mines with a transition to multi-product production of clean drinking water, utilization of methane, secondary coal from rock dumps and sludge reservoirs, low-potential thermal energy of mine groundwaters and associated raw materials from desalination waste. Methods. The research uses an integrated approach, which includes an analysis of existing experience and available complex coal mining technologies, laboratory studies of mine water desalination technology by the reverse osmosis method with thermal distillation of concentrated brine, and chemical analysis using ElvaX laboratory equipment. Findings. This paper presents the research results of a comprehensive analysis of mineral raw material resources related to coal mining. The technically achievable energy potential that can be produced from the secondary coal of rock dumps and sludge reservoirs has been determined, which in total is 183.3 TJ. The annual heat potential of methane gas utilization has been estimated, which in total of PJSC DTEK Pavlohradvuhillia’s mines reaches 7.1 PJ. The possibility of extracting up to 1.12 TJ/year of associated thermal energy from the water-drainage installation of mine complexes has been determined. For the conditions of the Zakhidno-Donbaska mine, the authors of the paper have developed a technological scheme for the water preparation process by the reverse osmosis with the desalination brine treatment by the method of multistage evaporation on adiabatic evaporators. Originality. For the first time, the energy flows related to coal mining technology have been comprehensively analyzed for the possibility of their joint use to cover the needs of the mine complex. The prospects for complex mining of mineral resources have been assessed based on the adaptation of the mine complex production facilities to the multi-product production of clean drinking water, utilization of methane gas, low-potential thermal energy from mine groundwaters and secondary raw materials of desalination waste. Practical implications. The proposed set of technological solutions will ensure the sustainable development and diversification of the production of PJSC DTEK Pavlohradvuhillia coal-mining enterprises, as well as the effective transformation of coal-mining cities during the period of transition from mono-product production to the creation of multi-business production complexes that comply with ESG principles. The creation of multi-product mine complexes capable of producing not only coal, but also heat and associated mineral raw material resources, should become a guarantee of stable social-economic development of coal-mining regions.

Energy and exergy analysis of a renewable energy-driven ion recovery system for hydroponic greenhouses

Providing agricultural needs is a common issue, especially in areas suffering from hot weather, freshwater scarcity, and unsuitable soil for farming. This paper aims to design and analyze a renewable energy-driven ion recovery system for hydroponic greenhouses using energy and exergy analyses. The objectives of the designed multigeneration system are recovering beneficial ions from crystallizing desalination waste brine, providing the needed fertilizers for hydroponic farming, integrating wind energy and a high-temperature fuel cell into the system to generate electricity uninterruptedly, integrating solar thermal energy into the system to generate the required heat for the absorption cooling unit. This study performs thermodynamic analysis on the system by writing energy, entropy, and exergy balance equations and evaluates the efficiencies of the subsystems and the overall system. Several sensitivity analyses are conducted to obtain the effects of different parameters on the system, such as the mass flow rate, salinity, and recovery ratio. This study proposes a unique integrated system that provides a new sustainable way to recover the needed ions for hydroponic farming from saline groundwater, in addition to groundwater desalination, using freezing desalination and electrodialysis systems assisted with renewable energy resources, in a more sustainable, efficient, and feasible manner. The system's total required electrical and thermal energy values are 518 kW and 150 kW, respectively, with overall energy and exergy efficiencies of 16.1 % and 13.4 %, respectively. The output mass flow rate amount of the recovered ions are Sodium (Na) 4.5 g/s, Sulphate (SO4) 0.624 g/s, Magnesium (Mg) 0.298 g/s, Calcium (Ca) 0.0936 g/s, and Potassium (K) 0.089 g/s.

Comparative Life Cycle Assessment of Uranium Recovery from Brine

• Once industrialized uranium recovery from brine is a feasible process. • Amidoximated adsorbents have a lower environmental impact than conventional methods. • Hazardous waste disposal and hydroxylamine are the most influenceable parameters of the system. • Solar energy has the least environmental impact compare to the other energy alternatives. With the increase in world population and the associated increase in raw material, clean water and energy demands, seeking for innovative and sustainable methods to decrease human-made environmental footprint becomes a task of utmost importance to reduce emissions and waste generation. Uranium-based atomic energy generation has an enormous potential to efficiently supply energy demand at the cost of high environmental impact on water bodies. Therefore, estimating the environmental impacts of the uranium recovery systems from desalination waste is a necessity. This study assessed the environmental impact of uranium recovery method from brine via AF1 and PAN-AO amidoximated adsorbents and compared them with the conventional uranium mining methods. As a life-cycle impact assessment method International Reference Life Cycle Data System was conducted with 16 impact categories considering cradle to gate analysis. The results for AF1, PAN-AO and all conventional uranium extraction methods showed that recovery of uranium in the long run is more effective than the conventional procedures. The sensitivity analysis results reveal that hydroxylamine, hazardous waste disposal are the most influential parameters during the uranium recovery via adsorbent methods. Comparative analysis between energy sources used in adsorbent recovery processes indicated that solar energy has the lowest environmental impacts among all kinds of energy scenarios. This study concluded that an alternative sustainable industrial process to obtain uranium is actually applicable. Hence, developing a uranium recovery strategy from brine should be considered while uranium mines are under investigation. Graphical Abstract .

Hygienic Aspects of the Use of Desalinated Sea Water for Drinking and Household Purposes: A Literature Review

Background. Uneven distribution of fresh water sources on the land surface encourages a search for effective techniques of potable water preparation by desalination of seawater. Hygienic issues of such desalination methods as distillation, reverse osmosis, electrodialysis, and ion exchange have been investigated by now and appropriate limitations, requirements, and additional measures to ensure safety of desalinated drinking water have been established. Objective. To summarize and systematize the results of studying characteristics of various methods of seawater desalination for its further use for drinking and household purposes. Materials and methods. We conducted a systematic review of studies published in Russian and in English, found in the PubMed and Web of Science databases, and selected 40 literary sources containing an empirical assessment of effectiveness of seawater desalination and preparation of drinking water. We also scrutinized regulatory documents and guidelines of domestic sanitary legislation. The research results were systematized by the main desalination methods. Results and discussion. We established that the use of seawater for the preparation of fresh water for drinking and household purposes is becoming increasingly widespread around the world. Drinking water obtained from seawater, in all cases, requires additional treatment and measures to optimize its mineral composition and protect against microorganisms. Conclusion. The main challenges of ensuring sanitary and epidemiological wellbeing of the population when using desalinated seawater for drinking and household purposes include selection of a source, arrangement of sites of water intake properly protected from natural and man-made pollution, substantiation of techniques and modes of preliminary preparation of source seawater adequate to its composition, basic desalination, ensuring safety of products of destruction and migration of toxic substances from reagents and materials of desalination plants, additional conditioning with the necessary elements and disinfection of the prepared water, as well as environmental protection from desalination waste.

Feasibility Study of Net CO2 Sequestration Using Seawater Desalination Brine with Profitable Polyproduction of Commodities

We present a profitable pathway from desalination waste brines to negative CO2 emissions. The method, termed ‘brine to bricks’ (BtB), mineralizes CO2 as nesquehonite (MgCO3･3H2O) using the Mg content of brines. Fresh water, gypsum (CaSO4･2H2O), halite (NaCl), mirabilite (Na2SO4･10H2O), sylvite (KCl), and hydrochloric acid are concurrently produced. To prevent ‘carbon leakage’, BtB does not rely on external chemicals, fossil fuel-derived heat and power, or captured CO2. BtB selectively precipitates CaSO4･2H2O, NaCl, and Na2SO4･10H2O by evaporative concentration and temperature-control. The remaining Na+ and K+ ions are separated as NaCl and KCl from the magnesium chloride slurry by hydrochloric acid-based precipitation. Super-azeotropic hydrochloric acid is regenerated from the slurry using a novel method: low hydration magnesium chloride addition. Purified magnesium chloride is decomposed to amorphous MgO prior to reaction with ambient CO2. The current NET potential of BtB, including the CO2 emissions from desalination, is 136 MtCO2/y. In the current market, BtB can operate at a profitability up to $266/t-CO2, dependent primarily on the availability of waste heat and the local performance of renewable energy. Based on current desalination adoption projections, BtB could remove 0.350-1.784 GtCO2/y by 2050 while providing substantial increases in fresh water, construction materials, and chemicals that are of use to other negative emission technologies.

Preparation of struvite from desalination waste

This research aims to study the preparation of struvite with the desalination waste (brine water) as magnesium source. In the present work, it has studied the precipitation of struvite and controlling struvite crystallization. The precipitation of struvite was investigated in desalination waste containing Mg:N:P molar ratio 1:1:1; 1:1:2 and 1:2:1 at room temperature on pH 9.10 and 11, respectively. Characterization of struvite crystal was performed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR); field-emission scanning electron microscopy (SEM), Thermogravimetry Analysis (TGA)/Differential Thermal Analysis (DTA) and BET surface area analysis. The XRD analysis showed that struvite crystallization was formed. FTIR spectra of struvite revealed the presence of water of hydration, PO bond, NH bond, and metal-oxygen bond. SEM images suggested that struvite had the irregular shape in different morphologies. From TGA/DTA analysis, the struvite crystal is unstable thermally and the loss of water of hydration starts above room temperature. BET data showed that the struvite pore was mesopores which are textural pores occurred with aggregates of plate-like particles.

Aspectos socioambientais e qualidade da água de dessalinizadores nas comunidades rurais de Pentecoste-CE

Os dessalinizadores de água salobra de poços são bastante utilizados para dotar as comunidades rurais do semiárido brasileiro com água potável, sendo considerada uma tecnologia social de convivência com a seca. No entanto, na dessalinização, além da água potável, é gerada uma água residuária (rejeito) altamente salina que pode gerar sérios impactos ambientais negativos. Objetivou-se avaliar a qualidade da água e a percepção dos usuários quanto aos aspectos socioambientais relacionados à utilização de equipamentos de dessalinização instalados em oito localidades em Pentecoste, Ceará (Mulungu, Muquenzinho, Irapuá, Macacos, Barra do Leme, Capivara, Lagoa da Porta e Providência). Em cada localidade, foram coletadas três amostras de água do poço, dessalinizada e de rejeito, para caracterização físico-química. Os valores de CE para o rejeito variaram de 4,2 a 7,6 dS m-1, representando riscos para o ambiente de acordo com padrões estabelecidos mundialmente. A localidade de Muquenzinho apresenta os maiores valores de pH, CE, Na e Ca para água do poço, dessalinizada e rejeito, em relação às demais localidades. A maior parte do rejeito gerado é utilizada para alimentação animal e a grande maioria da população, independente da localidade, não tem conhecimento se o uso desse rejeito causa algum dano à saúde humana ou ao ambiente.

Chemical Composition of Saline Sources as Suppliers of Minerals for Ruminants

This study aimed to evaluate the mineral composition of solid residues (SR) from desalination waste (DWSR), saline water (SWSR) and aquaculture ponds (APSR), and to discuss the results based on ruminant requirements. Mineral determined were K, P, Ca, Mg, S, Cu, Fe, Mn, Zn, Na, Cl, Ni, Pb, Cd and Cr, from 24 samples, 4 DWSR, 10 SWSR and 10 APSR, with three replicates. Desalination waste solid residue, SWSR and APSR had large variation of minerals. Saline water solid residue and DWSR presented potential to be used as source of Na and Cl, while the APSR can contribute Ca. All examined saline sources were poor in P, Ca and trace minerals except the APSR, showing a considerable concentration of Ca. Some samples of SWSR and APSR presented mineral concentrations that may be potentially toxic to ruminants.

Mineral mixtures from solid salt residues for lambs

The objective of this study was to evaluate water, mineral, feed and nutrient voluntary intakes, in addition to dry matter and nutrient digestibility and the nitrogen balance of lambs fed three mineral supplements. The first treatment consisted of solid salt residue (SSR) from an aquaculture tank; the second contained SSR from desalination waste; and the third treatment was control, which corresponded to the supplementation of a commercial mineral supplement. The study lasted 20 days, the first 15 of which were used for animals to adapt to the pens and diets, and the last five days were used for data collection. Twenty-four castrated male lambs with a body weight of 19.72±2.52 kg were utilized in the experiment. The mineral supplements evaluated did not affect the intake and digestibility of the dry matter and nutrients, the water and mineral-salt intake or nitrogen balance. Mineral supplements produced from the SSR from aquaculture tanks and from the desalination waste did not reduce feed, nutrient and water intakes or nutrient digestibility, which suggests that these raw materials can be used in the elaboration of mineral mixtures for lambs.