Reverse Osmosis Technology Research Articles

Study Recycling Effluents of Hospital WWTP with Reverse Osmosis

Reverse osmosis (RO) membrane technology has been used extensively in seawater desalination, drinking water production, brackish water treatment, and industrial wastewater treatment, whereas in hospital wastewater treatment plants (WWTP) has not been much studied. Effluents of hospital WWTP can still be reprocessed with filtration technology to improve its quality, so that it can replace the role of clean water that has been taken from ground water, and can even save water use by the Regional Water Supply Company. This study aims to examine the performance of reverse osmosis (RO) technology for recycling effluents of hospital WWTP. The results showed that the reverse osmosis (RO) system with a polyamide membrane proved to be effective for recycling effluents of hospital WWTP. The value of the concentration of processed water (product) RO when viewed from the TDS (Total Dissolved Solid) and COD (Chemical Oxygen Demand) parameters has decreased and meets clean water quality standards according to existing regulations. Increased operating time causes a decrease in permeate flux. Increased operating pressure causes increased permeate flux and rejection efficiency. The use of RO systems with polyamide membranes is expected to be the best choice for recycling effluents of hospital WWTP under current conditions.

Energy, Exergy, and Thermo-Economic Analysis of Renewable Energy-Driven Polygeneration Systems for Sustainable Desalination

Reliable production of freshwater and energy is vital for tackling two of the most critical issues the world is facing today: climate change and sustainable development. In this light, a comprehensive review is performed on the foremost renewable energy-driven polygeneration systems for freshwater production using thermal and membrane desalination. Thus, this review is designed to outline the latest developments on integrated polygeneration and desalination systems based on multi-stage flash (MSF), multi-effect distillation (MED), humidification-dehumidification (HDH), and reverse osmosis (RO) technologies. Special attention is paid to innovative approaches for modelling, design, simulation, and optimization to improve energy, exergy, and thermo-economic performance of decentralized polygeneration plants accounting for electricity, space heating and cooling, domestic hot water, and freshwater production, among others. Different integrated renewable energy-driven polygeneration and desalination systems are investigated, including those assisted by solar, biomass, geothermal, ocean, wind, and hybrid renewable energy sources. In addition, recent literature applying energy, exergy, exergoeconomic, and exergoenvironmental analysis is reviewed to establish a comparison between a range of integrated renewable-driven polygeneration and desalination systems.

Comparison of Nanofiltration with Reverse Osmosis in Reclaiming Tertiary Treated Municipal Wastewater for Irrigation Purposes.

This study compares the performance of nanofiltration (NF) and reverse osmosis (RO) for the reclamation of ultrafiltered municipal wastewater for irrigation of food crops. RO and NF technologies were evaluated at different applied pressures; the performance of each technology was evaluated in terms of water flux, recovery rate, specific energy consumption and quality of permeate. It was found that the permeate from the reverse osmosis (RO) process complied with Food and Agriculture Organization (FAO) standards at pressures applied between 10 and 18 bar. At an applied pressure of 20 bar, the permeate quality did not comply with irrigation water standards in terms of chloride, sodium and calcium concentration. It was found that nanofiltration process was not suitable for the reclamation of wastewater as the concentration of chloride, sodium and calcium exceeded the allowable limits at all applied pressures. In the reverse osmosis process, the highest recovery rate was 36%, which was achieved at a pressure of 16 bar. The specific energy consumption at this applied pressure was 0.56 kWh/m3. The lowest specific energy of 0.46 kWh/m3 was achieved at an applied pressure of 12 bar with a water recovery rate of 32.7%.

Electronic properties of defective graphene functionalized with oxygen and hydroxyl groups for molecular sieve

Sub nanometer-defective-graphene, such as graphene with vacancies and graphene oxide, is promising candidates to overcome the water permeability of membrane materials for reverse osmosis technology, which is the leading technology for desalination and water treatment. The advantage of graphene-based materials in this area is attributed to their ability to adsorb contaminants by oxygen-containing functional groups at defects on graphene sheets. In this study, the interaction mechanism between water molecules and defective graphene, including pyridine defective graphene and pyridine graphene oxide, is described through electronic properties by a DFT calculation. The calculation was performed using the pseudopotential plane-wave method by Quantum Espresso with cut-off energy of 40 Rdy and supercell of 4x4 with in-plane periodicity containing 32 atoms. The orbital hybridization of C atom changed from sp2 to sp3 when it bonded to the O atom instead of neighboring C atoms in the graphene structure, led to the formation of a negative charge on the graphene sheet. In particular, hybrid sp2/sp3 orbitals was created on C atoms, which formed the epoxy group with the adsorption energy of -5.80 eV. In the models of monovacancy of graphene (defective graphene) and various positions of oxygen on defective graphene (graphene oxide), charge re-arrangement due to vacancy or presence of oxygen atom and weak binding energy between graphene and water molecules are responsible for attracting cations and allowing water molecules to pass through. The negative charge areas were thought to help increase the spacing of the functionalized defective graphene sheets, creating a path for water molecules to pass through. In addition, the computational model also showed the (non)-magnetic moment of the functionalized defective graphene depending on the functional group attached at the defect position.

Overview on reverse osmosis technology for water treatment

Overview on reverse osmosis technology for water treatment

Life-Cycle Assessment of the Wastewater Treatment Technologies in Indonesia’s Fish-Processing Industry

In this paper, a comprehensive life-cycle assessment (LCA) is carried out in order to evaluate the multiple environmental-health impacts of the biological wastewater treatment of the fish-processing industry throughout its life cycle. To this aim, the life-cycle impact assessment method based on endpoint modeling (LIME) was considered as the main LCA model. The proposed methodology is based on an endpoint modeling framework that uses the conjoint analysis to calculate damage factors for human health, social assets, biodiversity, and primary production, based on Indonesia’s local data inventory. A quantitative microbial risk assessment (QMRA) is integrated with the LIME modeling framework to evaluate the damage on human health caused by five major biological treatment technologies, including chemical-enhanced primary clarification (CEPC), aerobic-activated sludge (AS), up-flow anaerobic sludge blanket (UASB), ultrafiltration (UF) and reverse osmosis (RO) in this industry. Finally, a life-cycle costing (LCC) is carried out, considering all the costs incurred during the lifetime. The LCA results revealed that air pollution and gaseous emissions from electricity consumption have the most significant environmental impacts in all scenarios and all categories. The combined utilization of the UF and RO technologies in the secondary and tertiary treatment processes reduces the health damage caused by microbial diseases, which contributes significantly to reducing overall environmental damage.

Benchmarking of scaling and fouling of reverse osmosis membranes in a power generation plant of paper and board mill: an industrial case of a paper and board mill study

The present study reports the characterization of reverse osmosis (RO) technology at water treatment plant Cogen-2 in paper and Board mills, Pakistan. RO is a commonly used process to obtain de-mineralized water for high-pressure boiler operation in thermal power plants. Scaling and fouling in three-stage RO plants is a major challenge in chemical industry due to the use of raw brackish water in the power plant of paper and board mills. In our study, the feed water quality of RO was changed from soft water to raw water to make it economical. The cleaning frequency was increased three times than normal, which was unsafe for operation and it was required to control scaling and fouling to achieve the desired result. Differential pressures behavior of all stages for 2-month data was observed without acid treatment, and the results of Langelier Saturation Index (LSI) control parameters (temperature, pH, total dissolved solids, calcium hardness, and alkalinity) clearly showed the abnormality. To optimize scaling and fouling of RO, the LSI factor was controlled in total reject water for the next 2 months by acid treatment in feed water. Duration of chemical cleaning and membranes’ life has been extended by fouling and scaling control. Understanding the effect of operational parameters in RO membranes is essential in water process engineering due to its broad applications in drinking water, sanitation, seawater, desalination process, wastewater treatment, and boiler feed water operation. The product flow increased from 18.3 to 19.9 m3/h, and this was due to a decrease in the rejection flow from 8.2 to 6.7 m3/h. The total reject stream pressure also increased from 8.1 to 9 bar. A lower value of LSI of 1.6 is obtained in the reject water stream after the acid treatment.

Ma’an – a new approach to the autonomous building

The paper describes the general principles of autonomous building operation. Derived from those, a building concept, which ensures energy and water self-sufficiency, has been presented. Another important benefit is the minimization of a carbon footprint – both during construction and operation. The proposed solutions are based on a system combining the technology of a cooling tower and a solar updraft tower enhanced with reverse osmosis technology and others. All of this has been achieved by creating an original architecture that matches its place of origin and functions.

A Comprehensive Membrane Process for Preparing Lithium Carbonate from High Mg/Li Brine.

The preparation of Li2CO3 from brine with a high mass ratio of Mg/Li is a worldwide technology problem. Membrane separation is considered as a green and efficient method. In this paper, a comprehensive Li2CO3 preparation process, which involves electrochemical intercalation-deintercalation, nanofiltration, reverse osmosis, evaporation, and precipitation, was constructed. Concretely, the electrochemical intercalation-deintercalation method shows excellent separation performance of lithium and magnesium, and the mass ratio of Mg/Li decreased from the initial 58.5 in the brine to 0.93 in the obtained lithium-containing anolyte. Subsequently, the purification and concentration are performed based on nanofiltration and reverse osmosis technologies, which remove mass magnesium and enrich lithium, respectively. After further evaporation and purification, industrial-grade Li2CO3 can be prepared directly. The direct recovery of lithium from the high Mg/Li brine to the production of Li2CO3 can reach 68.7%, considering that most of the solutions are cycled in the system, the total recovery of lithium will be greater than 85%. In general, this new integrated lithium extraction system provides a new perspective for preparing lithium carbonate from high Mg/Li brine.

WITHDRAWN: Effects of Additives and Conductors on Properties of Conducting Porous Composite Based on Activated Carbon

Climate change is increasingly clear and threatening to human life. One of the consequences of climate change is the increase of sea level leading to saline intrusion and serious shortage of fresh water. Today, some technologies are used to treat saline water such as Reverse Osmosis technology (RO), Multi-Effect Distillation (MED) technology, and Multi-Stage Discharge Technology (MSF), Electrodialysis (ED) and Capacitive Deionization (CDI). Among them, CDI technology is a technique for energy-saving and economical. The conductive composite electrode based on activated carbon from Tra Bac coconut shell charcoal were fabricated which were used as a electrode for CDI device. In this study, effect of adhesives and conductors on characterization and properties of the materials was investigated. The adhessive of PVDf and conductor of CNTs was chosen. With ratio of AC/CNTs = 9:1, the composite had a specific surface area of BET of about 517 m2/g and pore size of 1.71 nm.

Large-scale desalination based on parabolic trough collectors and double-effect absorption heat pumps

This paper focuses on an analysis of the current situation of distillation and reverse osmosis technologies and their relationship with renewable energies, to the extent that there is a strong trend in the use of distillation and reverse osmosis technologies. Large-scale seawater desalination using renewable energy is not developed, so a detailed study of the combination of renewable energy facilities, reverse osmosis, and distillation systems are needed to be effective and competitive compared to the use nonrenewable energy. Solar multiple is a very important parameter in the solar thermal industry. This is in the range of 1.5 – 3 and depends on the relationship between storage and plant power. This parameter is important because it reflects a balance between the cost of the parabolic trough collectors and the total of the solar thermal plant. If the same criterion is followed, with a thermal gap of 100 °C, chosen for the parabolic trough collectors sizing, the solar multiple in the system object of this article, has a value higher than 3. The proposed system employs renewable energies for reducing the downtime of the desalination plants, doing possible that the desalination plants being competitive in sites with poor quality solar radiation.

Preparation and characterization of different geometrical shapes of multi-bore hollow fiber membranes and application in vacuum membrane distillation

Multi-bore hollow fiber membranes were prepared through phase inversion spinning process using new locally designed spinnerets of various geometrical shapes. The spun cylindrical-like, rectangular or ribbon-like, and triangular-like are prepared, dried, and characterized by scanning electronic microscope. Fibers of circular (seven, five, and four bores) shape, rectangular of five bores, and triangular of three bores were chosen to study the effect of both geometrical configuration and the number of bores on the amorphous structure and the mechanical properties of the membranes. Membrane geometry, surface amorphous, and bore arrangements are very sensitive to the operating conditions, especially the extrusion and drawing rates. Three polymeric blends of different compositions are used to prepare multi-bore hollow fiber membranes. This study revealed that the blend composition of PES 16%, PVP 2%, PEG 2%, diethylene glycol 2%, and NMP 78% gives excellent mechanical properties. Optimization of the preparation conditions also developed, where the dope flow rate, the bore flow rate, and the air gap were 1.14 cm3 s−1, 1.1 cm3 s−1, and 0 cm, respectively. Furthermore, this study proved that the circular arrangement has high mechanical strength. The prepared seven-MBHF membranes were applied in the membrane distillation process, a solution of 35 g/l NaCl was used to test the membrane performance, and the achieved flux and rejection were 28.32 L/m2 h and 98.9%, respectively. This performance demonstrated that the prepared membrane in this way is suitable to compete with conventional reverse osmosis technology that uses single track hollow fibers.

ASSESSMENT OF FUTURE WATER, ENERGY, AND FOOD NEXUS BY USING WEAP AND LEAP MODELS IN THE STATE OF KUWAIT

With the global population growing (over seven billion), accompanied by escalating economic crises, mismanagement of natural resources, climatic changes, and uncertainties, and increasing poverty and hunger, the world is opposing critical periods of serious challenges. This paper aims to develop an integrated dynamic model for the WEF system for all governances in the State of Kuwait and future demand with and without climate change. Additionally, identifying proper opportunities in the WEF system in Kuwait. The aim is achieved by building an integrated dynamic model and analyzing it via using WEAP and LEAP software. The business as usual scenario concluded that increasing water, energy, and food within the next 17 years for all governorates. Besides that, climate change will also affect increasingly upon the WEF system. The impact is expected to rise, on average between 2 to 4% in the period 2017-2035 with total cumulative demand about 3144 Mm3. By using several interventions, management policies would help the water, energy, and food system to ensure its sustainability. The several interventions, such as reducing per capita consumption, saving devices, population control, and using reverse osmosis technology, will reduce the demand by about 50% by the year 2035.

Hybrid electrochemical microfiltration treatment of reverse osmosis concentrate: A mechanistic study on the effects of electrode materials

The reverse osmosis (RO) technology is promising as a key process for water reuse, but the RO brine (concentrate) needs proper treatments for minimal liquid disposals. This study investigated the potential of hybrid electrochemical microfiltration for the treatment of the RO concentrate from a municipal wastewater reuse plant. Two anodes (active Ir-RuOx and non-active Sb-SnO2) and two cathodes (stainless steel and carbon felt) were employed and compared in terms of the contaminants removal. The electrochemical microfiltration treatment achieved a substantial removal of color, turbidity, chemical oxygen demand, and fluorophores. However, the removal of the total nitrogen and organic carbon was limited. Then, mechanistic studies on the used electrode materials for the electrocatalysis of the RO concentrate were further conducted. The electrocatalysis that used a non-active anode improved the mineralization of the organics, whereas the active anode enhanced the denitrification. The combined use of the two anodes enabled the enhancement of the overall removal efficiencies. In addition, the oxidants (reactive chlorine/oxygen species) responsible for the organics and the nitrogen removals were elucidated. Overall, it was revealed that the electrochemical microfiltration that utilizes proper electrode combinations is a promising option for enhancing the treatment of RO concentrates with minimal disposals.

Community De-fluoridation - Experience in Kaiwara Village, Chikkaballapur District, Karnataka, India

Background and objective: Reverse osmosis technique is an adequate method for treating ground water for reducing the burden of abnormal levels of fluorides. The method protects the general population from diseases associated with high fluoride levels in the body. The objective of the present study was to assess the suitability and sustainability of reverse osmosis technology for community de-fluoridation of water used for cooking and drinking purposes in Kaiwara village, Karnataka. Methodology: This interventional study was conducted between July 2012 and June 2014 at Kaiwara village, Karnataka using reverse osmosis technique for de-fluoridation of water used for drinking and cooking. Complete chemical analysis of water was done before intervention, and processed water supplying the village was tested every six months after intervention for about two years. The variation in chemical concentrations of various components were analysed. Results: The mean baseline level of fluoride in untreated water was 2.075 mg/dl (above the safety limit), which dropped to 0.08 mg/dl at the end of first six months following the intervention, 0.042 mg/dl in 12 months, 0.1 mg/dl at 18 months and 0.01 mg/dl at 24 months after intervention, which were all below the safety limits for India in the treated water. The mean total dissolved solids in the water was 542.25 mg/dl in the untreated water, which dropped to zero after the first six months, remained at zero in the next six months, rose to 120 mg/dl at 18 months and then dropped to 70 mg/dl at 24 months in the treated water. The observed values were reduced significantly. Discussion: The study concluded that it is possible to set up a community de-fluoridation plant using reverse osmosis technique at Kaiwara village, Karnataka which is economically sustainable and acceptable by local population.

The influence of membrane surface properties on the radionuclide mass transfer process in reverse osmosis

Reverse osmosis (RO) technology has been playing an increasingly important role in radioactive wastewater treatment. In this study, the influence of membrane surface properties on the trace radionuclide (Cs+) mass transfer process in polyamide RO membrane was investigated. The Cs+ mass transfer process was described using the solute permeability coefficient (B) with the solution-diffusion with defects (SDWD) model. Several modified RO membranes grafted by different polymers were fabricated to provide different properties, including surface charge, surface roughness and hydrophilicity. The results of correlation analyses demonstrated that BCs+ was independent of both the membrane hydrophilicity and surface roughness. In contrast, there was a significant correlation between BCs+ and the membrane surface charge. The zeta potential exhibited a strong correlation with BCs+. BCs+ decreased from (7.78 ± 0.70) × 10−7 to (7.19 ± 2.95) × 10−9 m/s as the zeta potential increased from −43.57 to 21.2 mV. The results of this study indicated that the membrane surface charge of RO membrane played a key role in the radionuclide mass transfer process. Fabricating positively charged RO membranes could significantly obstruct the radionuclide mass transfer process. The results provided fundamental insights into the mechanisms of the radionuclide mass transfer process in the RO membrane, which emphasized the application prospects of membrane surface modification as a method for the treatment of radioactive wastewater.

Surface functionalization of reverse osmosis membranes with sulfonic groups for simultaneous mitigation of silica scaling and organic fouling

Organic fouling and inorganic scaling are the main hurdles for efficient operation of reverse osmosis (RO) technology in a wide range of applications. This study demonstrates dual-functionality surface modification of thin-film composite (TFC) RO membranes to simultaneously impart anti-scaling and anti-fouling properties. Two different grafting approaches were adapted to functionalize the membrane surface with sulfonic groups: (i) non-specific grafting of vinyl sulfonic acid (VSA) via redox radical initiation polymerization and (ii) covalent bonding of hydroxylamide-O-sulfonic acid (HOSA) to the native carboxylic groups of the polyamide layer via carbodiimide mediated reaction. Both approaches to graft sulfonic groups were effective in increasing surface wettability and negative charge density of the TFC-RO membranes without significant alteration of water and salt permeabilities. Importantly, we verified through surface elemental analysis that covalently bound HOSA effectively covers the native carboxylic groups of the PA layer. Both the VSA and HOSA membranes exhibited lower flux decline during silica scaling and organic (alginate) fouling relative to the control unmodified membrane, demonstrating the unique versatility of sulfonic groups to endow the TFC-RO membranes with dual functionality to resist scaling and fouling. In particular, the HOSA membrane showed excellent physical cleaning efficiencies with water flux recoveries of 92.5 ± 1.0% and 88.4 ± 6.4% for silica scaling and alginate fouling, respectively. Additional results from silica nucleation experiments and atomic force measurements provided insights into the mechanisms of improved resistance to silica scaling and organic fouling imparted by the surface-functionalized sulfonic groups. Our study highlights the promise of controlled functionalization of sulfonic groups on the polyamide layer of TFC membranes to enhance the applications of RO technology in treatment and reuse of waters with high scaling and fouling potential.

What We Learn From Innovation Failure A Review of Clean Water Postpaid Service in Remote Island Indonesia Using Sea Water Reverse Osmosis (SWRO) Technology

<p>Every project from government, should be or must be delivering a great mission, especially for undeveloped areas. But the fact is, there were plenty of them failed to sustain then became out of order. This article uncovers the reason behind one of central government project supplying clean water to remote area that has a big tendency of failing to sustain its service. Using formulated factors of achieving the sustainability of clean water service as the framework, and social innovation approach as the tool of analysis, the result indicates that the service started to maintain its effective demand onerously due to dealing with the sociocultural of the users. What was missing from the system of the project for delivering the service and what solution must be taken will be discussed on this article.</p><strong>Keywords</strong>: sustainability, clean water service, social innovation, sociocultural

Irrigation with permeates to upgrade the quality of red pepper: a case study in Arava region, Israel

ABSTRACT Management of environmental resources presents challenges across agricultural production. In the case of the semi-arid region of Arava Valley in Israel, irrigation with groundwater brackish water is a widespread practice that has severe limitations. In this research studies are taking place for brackish groundwater upgrading for unrestricted use for the irrigation and sustainable agricultural production. The treatment system applies two main treatment stages: nanofiltration and reverse osmosis membrane process and, the pilot system with a capacity of around 1 m3/hr. Different mixtures of nanofiltration and reverse osmosis, Brackish and potable permeates are then applied for the irrigation of pepper crops. The field results with the graphical visualization approach using total ranking, multi-dimensional scaling, and clustering technique show that the conventional brackish feed water produces good results of relaxation time, total soluble solids and Vitamin C content. Treatment system using hybrid nanofiltration and reverse osmosis technology improves product quality related to the relative fruit colour red shade.

Performance Evaluation of Reverse Osmosis Technology for the Retention and Rejection of Cations

Water scarcity is a grand challenge that has always stimulated research interests in finding effective means for pure water production. . In order to overcome the challenge of water scarcity various efforts are being taken to develop and advance water production technologies. One of the process for producing clean water from a variety of sources is water desalination. Desalination refers to the process of removing the salts and contaminants from a water source in order to attain clean water which would be suitable for human consumption and domestic and industrial usage. Reverse Osmosis (RO) is currently one of the most reliable technique for water desalination and is being used as an alternative source for the production of clean water so that the water desalination costs are minimized.This paper aims to provide an overview on the various aspects of RO desalination process- the fundamentals, theory, and various parameters like concentration and pressure on the desalination process. This paper also discusses the synergic effect, which represents a serious challenge in RO processes (i.e. the effect of presence of one or more cations in the feed water).