NANOFLUID EMULSION MEMBRANE FOR WASTEWATER PURIFICATION AND HEAVY METAL RECOVERY

Abstract

The present invention discloses a nanofluid emulsion membrane for wastewater purification and recovery of heavy metals, including tin (Sn), tellurium (Te), antimony (Sb), cobalt (Co), mercury (Hg), lead (Pb), chromium (Cr), and cadmium (Cd). The membrane utilizes Al(OH)₃ nanoparticles dispersed in water to form a stable emulsion that selectively adsorbs around 99% of the heavy metals from industrial wastewater within 15 min of contact time. The membrane system offers high selectivity, efficiency, and reusability, providing a cost-effective and sustainable solution for wastewater treatment.

Specification

Description:FIELD OF THE INVENTION: The present invention relates to the field of wastewater treatment, specifically to the use of nanotechnology for environmental cleanup. The invention pertains to a nanofluid emulsion membrane designed for the purification of industrial wastewater and the recovery of toxic heavy metals, including tin (Sn), tellurium (Te), antimony (Sb), cobalt (Co), mercury (Hg), lead (Pb), chromium (Cr), and cadmium (Cd). The invention utilizes aluminum hydroxide (Al(OH)3) nanoparticles as the nanofluid dispersed in water as the base fluid for selective adsorption and removal of heavy metals. The invention aims to provide a highly efficient and environmentally friendly method for removing these hazardous contaminants from wastewater.________________________________________
3. BACKGROUND OF THE INVENTION: Industrial processes such as mining, electroplating, smelting, and semiconductor manufacturing generate wastewater containing harmful heavy metals, including tin (Sn), tellurium (Te), antimony (Sb), cobalt (Co), mercury (Hg), lead (Pb), chromium (Cr), and cadmium (Cd). These metals pose significant environmental and health risks, as they can accumulate in the food chain and cause chronic toxicity. Existing methods for the removal of heavy metals from wastewater include chemical precipitation, adsorption, ion exchange, and membrane filtration. However, these methods often face challenges such as high operational costs, low selectivity, fouling, and inefficiency at low metal concentrations. Nanofluids, which are suspensions of nanoparticles in fluids, exhibit unique properties that enhance mass transfer and adsorption processes. In this invention, Al(OH)₃ nanofluid is used in an emulsion membrane to improve the extraction of heavy metals from wastewater, providing a novel, effective solution for industrial effluent treatment.________________________________________
4. OBJECTIVES OF THE INVENTION: The primary object of this invention is to develop a nanofluid emulsion membrane for the efficient removal and recovery of heavy metals, specifically tin (Sn), tellurium (Te), antimony (Sb), cobalt (Co), mercury (Hg), lead (Pb), chromium (Cr), and cadmium (Cd) from industrial wastewater. Other specific objectives include: 1. To utilize Al(OH)₃ nanoparticles as the active agent for selective adsorption of heavy metals. 2. To employ water as the base fluid for forming the nanofluid emulsion. 3. To provide a cost-effective and environmentally friendly solution for industrial wastewater treatment. 4. To enable easy regeneration of the membrane, allowing multiple cycles of metal recovery and membrane reuse. 5. To improve the overall efficiency of metal extraction, even at low contaminant concentrations.________________________________________
5. SUMMARY OF THE INVENTION: The invention introduces a nanofluid emulsion membrane designed for the efficient removal and recovery of heavy metals, such as tin (Sn), tellurium (Te), antimony (Sb), cobalt (Co), mercury (Hg), lead (Pb), chromium (Cr), and cadmium (Cd), from wastewater. The membrane system utilizes Al(OH)₃ nanoparticles suspended in water as the base fluid, forming a stable emulsion that selectively adsorbs the heavy metals from the contaminated water. The membrane operates by passing wastewater through the nanofluid emulsion, where the Al(OH)₃ nanoparticles capture and retain the heavy metal ions. The emulsion is supported by a porous substrate that allows for efficient flow and prevents fouling. The system is designed to be easily regenerated, allowing for the desorption of heavy metals and reuse of the membrane for multiple treatment cycles. The membrane system is capable of being regenerated through a desorption process, allowing for multiple cycles of metal recovery and membrane reuse, making it a cost-effective and sustainable solution. ________________________________________
6. DETAILED DESCRIPTION OF THE INVENTION: The nanofluid emulsion membrane is composed of the following key components: • Nanoparticles: The membrane utilizes Al(OH)3/water nanofluid as it exhibit high affinity for the target heavy metals, including tin (Sn), tellurium (Te), antimony (Sb), cobalt (Co), mercury (Hg), lead (Pb), chromium (Cr), and cadmium (Cd). • Base Fluid: The base fluid was water which serves as the medium for dispersing the nanoparticles and forming a stable emulsion. Carrier fluid, extractant, and stripping agent employed were kerosene, 1-hexyl-3-methylimidazolium hexafluoro phosphate, and NaOH, respectively were used. • Emulsion Stabilizer: Span 80 was used to stabilize the emulsion and prevent phase separation over time. Fabrication of the Membrane The nanofluid emulsion membrane is fabricated using the following steps: 1. Nanoparticle Dispersion: The Al(OH)3 nanoparticles are dispersed in the water using magnetic stirrer followed by ultrasonicator form a uniform nanofluid. 2. Emulsion Membrane Formation: Membrane phase (W/O) was prepared by combining kerosene with 1-hexyl-3-methylimidazolium hexa fluorophosphate (extractant) and 0.03 vol% of Span-80 (surfactant) solution. This solution was then magnetically stirred for 15 min at 1000 RPM before being ultrasonicated for 20 min. A known concentration and volume of Al(OH)3 nanofuid was added to this membrane phase and ultrasonicated for 20 min at high intensity. The external feed phase was prepared from 100 ppm concentration of antimony potassium tartrate solution. This 30 mL of feed phase was combined with the 20 mL of the emulsion membrane phase to formulate the W/O/W emulsion nanofuid membrane. Mechanism of Heavy Metal Recovery 1. Adsorption: As the wastewater flows through the nanofluid emulsion membrane, heavy metal ions, such as tin, tellurium, antimony, cobalt, mercury, lead, chromium, and cadmium, are selectively adsorbed onto the surface of the nanoparticles within the emulsion. 2. Phase Separation: The heavy metals are trapped within the emulsion phase, preventing them from returning to the aqueous phase. This leads to an efficient separation of the metals from the wastewater. 3. Regeneration: The membrane can be regenerated by applying a desorption process that releases the adsorbed heavy metals, allowing for the recovery of the metals and the reuse of the membrane for multiple treatment cycles. ADVANTAGES OF THE INVENTION 1. High Selectivity: The Al(OH)₃ nanoparticles provide high selectivity for heavy metals, ensuring efficient removal of tin (Sn), tellurium (Te), antimony (Sb), cobalt (Co), mercury (Hg), lead (Pb), chromium (Cr), and cadmium (Cd). 2. Enhanced Efficiency: The nanofluid emulsion system improves the rate of adsorption and removal of heavy metals compared to conventional methods. 3. Regenerability: The membrane can be easily regenerated, enabling multiple treatment cycles and reducing operational costs. 4. Cost-Effectiveness: The use of water as the base fluid and Al(OH)₃ nanoparticles as the adsorbent makes the membrane system affordable and environmentally friendly. 5. Scalability: The membrane system is suitable for scaling up to industrial levels and can be applied across a variety of industries. ________________________________________ , Claims:Claim 1:
A nanofluid emulsion membrane for the purification of wastewater and recovery of heavy metals, including tin (Sn), tellurium (Te), antimony (Sb), cobalt (Co), mercury (Hg), lead (Pb), chromium (Cr), and cadmium (Cd), comprising Al(OH)₃ nanoparticles dispersed in water to form an emulsion, wherein the nanoparticles selectively adsorb heavy metals from the wastewater.
Claim 2:
The nanofluid emulsion membrane as claimed in Claim 1, wherein the membrane is supported on a porous substrate for enhanced wastewater diffusion and reduced fouling.
Claim 3:
The nanofluid emulsion membrane as claimed in Claim 1, wherein the emulsion is stabilized by a surfactant to prevent phase separation.
Claim 4:
The nanofluid emulsion membrane as claimed in Claim 1, wherein the membrane can be regenerated by desorbing the adsorbed heavy metals, allowing for reuse of the membrane.
Claim 5:
The nanofluid emulsion membrane as claimed in Claim 1, wherein the Al(OH)3 nanoparticles have a size range of 10-100 nm to enhance the surface area for heavy metal adsorption.

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