Technological innovation for the production of drinking water by membrane processes (original) (raw)
Related papers
Preliminary Studies on Membrane Filtration for the Production of Potable Water
Ultrafiltration (UF) systems have been used globally for treating water from resources including rivers, reservoirs, and lakes for the production of potable water in the past decade. UF membranes with a pore size of between 0.1 and 0.01 micrometres provide an effective barrier for bacteria, viruses, suspended particles, and colloids. The use of UF membrane technology in treating groundwater for the supply of potable water in the impoverished and rural village, Tshaanda (i.e., the study area) is demonstrated. The technical and administrative processes that are critical for the successful installation of the pilot plant were developed. Given the rural nature of Tshaanda, the cultural and traditional protocols were observed. Preliminary results of the water quality of untreated water and the permeate are presented. Escherichia coli in the untreated water during the dry season (i.e., June and July) was 2 cfu/100 ml and was ,1 cfu/100 ml (undetected) following UF, which complied with the WHO and South African National Standards and Guidelines of ,1 cfu/100 ml. During the wet/ rainy season (February) total coliform was unacceptably high (.2419.2 cfu/100 ml) before UF. Following UF, it dramatically reduced to acceptable level (7 cfu/100 ml) which is within the WHO recommended level of ,10 cfu/100 ml. Additionally, during the wet/rainy season E. coli and enterococci were unacceptably high (40.4 cfu/100 ml and 73.3 cfu/100 ml, respectively) before UF but were completely removed following UF, which are within the WHO and SANS recommended limit. The values for electrical conductivity (EC) and turbidity were constantly within the WHO recommended limits of 300 mS/cm corrected at 25uC and ,5 NTU, respectively, before and after UF, during dry season and wet season. This suggests that there is no need for pre-treatment of the water for suspended particles and colloids. Considering these data, it can be concluded that the water is suitable for human consumption, following UF. Citation: Molelekwa GF, Mukhola MS, Van der Bruggen B, Luis P (2014) Preliminary Studies on Membrane Filtration for the Production of Potable Water: A Case of Tshaanda
Desalination, 2003
Tunisia has utilized a large portion of its moderate water potential. Needs increase exponentially as a result of population growth and socio-economic development. Since the 80's, Tunisia has resorted to desalination of brackish water and particularly via membrane techniques to supply the traditionally deficient regions with good quality water and come up with a solution for industrial water utilities. The choice and the management of desalination technologies must be studied. With this aim, a national research program has been established to dealing with the optimal management of existing units with a view to propose technological schemes more adapted to the quality of the raw water. In the present work, three plants are studied. The first one is an RO fed by water drawn from a subsoil aquifer. The operating parameters show that partial iron oxidation and chlorine are responsible for the short life of modules. The second deals with the water from a deep geothermal layer. Membrane autopsies show that the fouling is essentially biological and that the shock treatment has led to a significant improvement. The third one is an EDR plant fed by dam water. The main difficulty is the turbidity fluctuation, the instantaneous adjustment of the dose injected into flocculant and coagulant which has led to a substantial improvement of the plant performances. The follow up and diagnosis are presented and discussed in the light of new trends in material.
Bulletin of the Faculty of Engineering. Mansoura University
This paper discusses the performance and characteristics of desalination membranes used in treatment of water for potable use. In this study, The Desalination Economic Evaluation Program (DEEP) is a spreadsheet tool originally developed for the IAEA by General Atomics and later expanded in scope by the IAEA, The DEEP-5.1 version program allows designers and decision makers to compare performance and cost estimates of various desalination and power configurations. Desalination options modeled include MSF, MED, VC,RO and hybrid systems. This paper presents the results of the operational performance of RO units in experimental scale. The rate of decline of productivity for a period 38 Days is examined and described by simple power law function. The evaluation of the solvent and salt permeability coefficients with the time of operation is quantified. The results show the recovery, pressure and conductivity across the membrane for 38 days test run. Also, the results show the effect of chemical additives and operational parameters on the performance of the membrane during the cleaning. Based on such individual RO module data (one year) the product flow rate and Total Dissolved Solids (TDS) performance is calculated and RO module replacement ratio can be estimated. These developments can be utilized to improve the quality of surface seawater feed to the level comparable to, or better than the water quality from the well water sources. These new developments enable a more advanced RO system design which should result in increased reliability and lower water cost. And compare the result of reverse osmosis desalination conventional system with a mathematical model is built and solved with ROSA computer programs to get results for the design calculations of the reverse osmosis mode used to remove salt from the feed water. The principles of the reverse osmosis mode, the conditions and factors affecting their operation, are discussed. The number of stages with their arrangements in the reverse osmosis mode is calculated using the ROSA Program. A mathematical model and computer programs including all the mentioned cases are built and applied on the reverse osmosis mode of water stations. The results of these calculations are compared with the practical results and showed a fair good agreement.
Drinking Water Treatment by Ultrafiltration Membrane: A Review
2018
With the improvement of living standards, people on drinking water quality is also put forward higher requirements, so the standard of drinking water is becoming more and more strict. Compared with conventional water treatment technology, membrane separation technology has good water quality, stable operation, small occupation area, easy to realize the automatic control, has an extremely wide application prospect in municipal water treatment industry. This method briefly introduces the domestic types and development situation of materials of preparing ultra-filtration membrane. Membrane filtration in drinking water treatment has become a more attractive technology in recent years as a possible alternative treatment.
Transportable membrane process to produce drinking water
Desalination, 2009
When natural disasters occur, the shortage of drinking water becomes a problem not only for the disaster victims, but also for the people involved in their rescue and safekeeping. A water purification unit has been designed, meeting specific criteria of efficiency, size, weight and power consumption. A hollow fiber ultrafiltration (UF) membrane module, with a 100 kDa cut off, has been chosen and integrated into a miniature pilot plant, transportable by plane and portable by four men. The power necessary for operating the pilot plant is 0.6 kW and can be provided by an electricity generator. In less than 30 min, the unit is ready for production. The maximum production reaches 1000 L h À1 , which can easily meet the demands of drinking water for the rescue team and disinfected water for medical care.
Membrane processes used for potable water quality improvement
Desalination, 2002
The tap water is often used as water source for different industries, however, the water repurification is required to meet the specification of technology. The effect of application of ultrafiltration (UF), nanofiltration (NE), reverse osmosis (RO) and membrane distillation (MD) processes on the quality of treated water was investigated. The removal of suspended solids and colloids obtained by UF process allowed the reduction of SDTls from 8 to 2. The NF process permitted to achieve the complete removal of dissolved organic carbon and the rejection of hardness between 60% and 87%. The rejection of TDS obtained in the RO system was at a level of 99.7%. The highest quality water (0.8 fLS/cm, 0.6 ppm TDS) was produced in the MD installation.
Groundwater purification by membrane technology
The Environmentalist, 2011
Hyperfiltration and nanofiltration membranes were tested with different water matrices for the removal of excess fluoride from underground water. Initially, the experiments were done with synthetic samples prepared by adding known amounts of sodium fluoride and calcium chloride in distilled water. The effect of feed water composition, pH, temperature of feed water, operating pressure, and feed water flow rate on separation efficiency of both types of membrane was studied by varying one parameter at a time and keeping all other parameters constant. Thus, the optimum operating conditions for the process were determined and after that ground water samples collected from three villages of district Gurgaon, Haryana, India (Farukhnagar, Wazirpur, and Mevka) were treated under optimum operational conditions. The mass transfer coefficient and membrane parameters were estimated for each data point using two-parameter model (Film theory and Solution-diffusion model) to study the concentration polarization on membrane surface. The nanofiltration membrane showed high percentage rejection of bivalent ions when compared to monovalent ions in a binary system. But in multicomponent system, when fluoride and calcium coexisted, the removal of fluoride was comparable to calcium removal because of the low solubility product of calcium fluoride. The results with RO membrane revealed that it removes practically all the ions present in water at high pressure, which need to be passed through a lime column to remineralize the water, to make it suitable for drinking purposes, whereas by running the system at low pressure which will further reduce the cost of operation, rejection percentage goes down to get permeate of required quality. List of symbols C Molar density of solution (kmol/m 3 ) D ij Coordinate direction perpendicular to the membrane (m) D SW Diffusion coefficient (m 2 /s) J S Solute volume flux (m 3 /m 2 s) J W Solvent volume flux (m 3 /m 2 s) k Mass transfer coefficient (m/s) K A Pure water permeability coefficient (kmol/m 2 kPa) K B Solute transport parameter (m/s) N i Molar flux of component, i (kmol/m 2 s) P Applied pressure across the membrane (bar) Dp Osmotic pressure difference across the membrane (bar) R Observed rejection (%) R* True rejection (%) d Thickness of concentration boundary layer (m)
Abstract Ultrafiltration (UF) systems have been used globally for treating water from resources including rivers, reservoirs, and lakes for the production of potable water in the past decade. UF membranes with a pore size of between 0.1 and 0.01 micrometres provide an effective barrier for bacteria, viruses, suspended particles, and colloids. The use of UF membrane technology in treating groundwater for the supply of potable water in the impoverished and rural village, Tshaanda (i.e., the study area) is demonstrated. The technical and administrative processes that are critical for the successful installation of the pilot plant were developed. Given the rural nature of Tshaanda, the cultural and traditional protocols were observed. Preliminary results of the water quality of untreated water and the permeate are presented. Escherichia coli in the untreated water during the dry season (i.e., June and July) was 2 cfu/100 ml and was ,1 cfu/100 ml (undetected) following UF, which complied with the WHO and South African National Standards and Guidelines of ,1 cfu/100 ml. During the wet/ rainy season (February) total coliform was unacceptably high (.2419.2 cfu/100 ml) before UF. Following UF, it dramatically reduced to acceptable level (7 cfu/100 ml) which is within the WHO recommended level of ,10 cfu/100 ml. Additionally, during the wet/rainy season E. coli and enterococci were unacceptably high (40.4 cfu/100 ml and 73.3 cfu/100 ml, respectively) before UF but were completely removed following UF, which are within the WHO and SANS recommended limit. The values for electrical conductivity (EC) and turbidity were constantly within the WHO recommended limits of 300 mS/cm corrected at 25uC and ,5 NTU, respectively, before and after UF, during dry season and wet season. This suggests that there is no need for pre-treatment of the water for suspended particles and colloids. Considering these data, it can be concluded that the water is suitable for human consumption, following UF.
The Use of Membrane Technologies of the CWTP to Obtain Quality Drinking Water
Journal of Ecological Engineering, 2021
The purpose of the study is a scientific and theoretical substantiation of the energy characteristics of ultra and nano filtration, which directly depend on the quality of the source water, to ensure reliable and uninterrupted operation of a combined water treatment plant (CWTP), to obtain high-quality drinking water in water supply systems intended for settlements and industrial facilities. The developed method of combined operation of a water treatment plant is based on membrane technology, the efficiency of which directly depends on the preliminary improvement of the quality of purified low-mineralized water using an energy-efficient membrane, post-treatment and subsequent disinfection. Indicators of the quality of treated water that meet regulatory requirements and indicators of improving the energy efficiency of the water treatment plant have been investigated and calculated on the basis of experimental data. The results of studies on low-mineralized water made it possible to obtain TDS (Total dissolved solids) with a total residual concentration of hardness and chlorides in the range of 0.77 mg/dm 3 without any problems. The proposed combined water treatment plant method is a priority among fundamental and applied works in the field of water treatment, it is intended for the purification of natural waters under conditions of increased anthropogenic loads on natural water sources.