Membrane processes are increasingly being used in drinking water treatment, to meet increased stringent water quality regulations.
Ultrafiltration (UF) has been widely used for advanced water treatment to remove colloidal particles, heavy metals, and some natural organic matter (NOM).
Ultrafiltration membranes have pore sizes ranging from 0.002 to 0.1 microns. It is primarily used in the pressure-driven separation of contaminants from water, such as colloids, particulates, and high molecular mass soluble species.
UF membranes are capable of removing all microbiological species as well as some viruses, while allowing most ionic inorganic matter to pass through, while retaining particulates and ionic organic species. This membrane can eliminate many water-soluble organic and microbiological matters, in a single process.
Is it possible to remove heavy metals through ultrafiltration?
Removing unwanted metals from water systems is a critical and difficult task, for environmental and chemical engineers.
Heavy metals are elements with atomic weights ranging from 63.5 to 200.6 and specific gravities greater than 5.0. Heavy metals are not biodegradable and build up in living organisms.
Ultrafiltration is presented as a useful technique for recovering heavy metals from aqueous solutions, without the addition of additional substances. Recovery of mixtures of iron (II) and iron (III), copper (II), and chromium (III) is specifically presented. Ceramic membranes are more resistant mechanically, chemically, and thermally than polymeric membranes.
Operation of ultrafiltration in removing heavy metals
UF eliminates dissolved and colloidal material at low transmembrane pressures. However, because the pore sizes of UF membranes are typically larger, than the pore sizes of heavy metal ions or molecular weight complexes, the metal particles can sometimes pass freely through the membrane.
Thus, enhanced UF has been proposed to achieve high metal ion removal. Metal removal efficiency by enhanced UF is affected by metal and surfactant characteristics, and concentrations, solution pH, ionic strength, and membrane operation parameters.
Tubular ultrafiltration is a more effective method of ensuring that the treated wastewater stream, is free of all precipitated metal hydroxide/sulphides/carbonates than conventional clarifier techniques. The resulting high-quality permeate can be reused in its current form, fed directly to reverse osmosis equipment, or discharged to sewer.
Currently, around 800 million people, or roughly one in every nine people, have limited access to improved water sources.
"Lack of access to safe drinking water and sanitation has killed children, at the rate of a jumbo jet crashing every four hours." As a result of its importance in human life, the water treatment industry has grown steadily and rapidly.
Among the various types of pollutant particles, ultrafiltration is used in water treatment to remove natural organic matter (NOM), which is a precursor of disinfecting by-products, and heavy metals.
How can we assist?
A wide variety of wastewater treatment options are offered by Netsol Water, including activated carbon, membrane filtration, RO Plants, flotation, coagulation, electrodialysis and many more advanced treatment plants, to eliminate heavy metals from wastewater and water.