Portable multi-stage water purification cylinder for emergency and outdoor use

Abstract

The invention provides a portable, hollow cylindrical water purification device comprising three vertically stacked compartments, each performing a different purification stage. The lower compartment contains a sediment filtration system to remove large particles and suspended solids. The middle compartment contains an activated carbon filter for adsorption of chemical contaminants and improvement of taste and odor. The upper compartment contains a UV-C sterilization unit powered by a small, manually operated generator or a solar-powered system, designed to inactivate bacteria, viruses, and other pathogens. The rotation speed of the UV-C cylinder is adjustable by varying the electrical current, allowing optimization of exposure time for different water conditions.

Description

[0001] Portable Multi-Stage Water Purification Cylinder for Emergency and Outdoor Use

[0002] Field of the Invention

[0003] The present invention relates to portable water purification systems. More particularly, it concerns a multi-stage cylindrical device designed for use in emergencies and outdoor environments where access to safe drinking water is limited. This invention addresses the urgent global need for reliable, lightweight, and multifunctional water purification technologies capable of operating without dependence on centralized infrastructure or continuous external energy supply. It is particularly applicable in situations such as natural disasters, military field operations, humanitarian aid missions, survival expeditions, and remote camping, where water from natural sources is often contaminated with suspended solids, pathogenic microorganisms, heavy metals, and persistent organic pollutants.

[0004] Background of the Invention

[0005] In many emergencies, such as natural disasters, military operations, survival scenarios, and outdoor activities in remote areas, individuals often lack access to safe drinking water (8, 9). In such circumstances, available water sources may be contaminated with a combination of physical debris, pathogenic microorganisms, organic pollutants, and heavy metals. Common portable water filters generally rely on a single purification method, such as mechanical filtration, chemical disinfection, or activated carbon adsorption (10). While these approaches can be effective for certain categories of pollutants, they often fail to provide comprehensive treatment against both microbial and chemical contaminants. Additionally, many existing devices are bulky, rely on continuous external power supply, or require extended processing time, which limits their usability in urgent situations.

[0006] Electrocoagulation is an electrochemical water treatment process that uses a direct current to dissolve metal ions from a sacrificial anode, typically aluminum or iron, into the water (11). These ions hydrolyze to form metal hydroxides, which act as coagulants that destabilize and aggregate suspended solids, emulsified oils, and dissolved heavy metals. This aggregation promotes floc formation, which can be separated by sedimentation or filtration. Electrocoagulation offers several advantages for emergency water purification: it requires no chemical additives, can remove turbidity, color, and toxic metals, and is effective against certain pathogens by damaging their cell membranes through localized oxidation and pH shifts.

[0007] Photocatalytic oxidation, in contrast, utilizes light energy — typically from ultraviolet (UV) radiation — to activate a semiconductor catalyst, most commonly titanium dioxide (TiO2) (12). Upon light activation, TiO2generates electron-hole pairs, which react with water and dissolved oxygen to produce highly reactive oxygen species (ROS) such as hydroxyl radicals (*OH) and superoxide anions (O2— ) (6, 13). These ROS are capable of oxidizing and mineralizing a broad range of organic contaminants, including pesticides, pharmaceuticals, and volatile organic compounds, ultimately converting them into harmless end products like carbon dioxide and water (14). Photocatalytic processes are also effective for the inactivation of bacteria, viruses, and protozoa by damaging their cellular structures and genetic material (15).

[0008] By integrating electrocoagulation and photocatalytic oxidation into a single compact, modular system, a synergistic effect can be achieved. Electrocoagulation first removes suspended solids, heavy metals, and colloidal matter, thereby reducing turbidity and improving light penetration, which significantly enhances the efficiency of the subsequent photocatalytic stage. This combination ensures that a wide spectrum of contaminants — physical, chemical, and biological — are addressed in a rapid, chemical-free, and energyefficient manner. The device can be designed to operate without a continuous external power source by incorporating hand-crank, solar, or small battery systems, making it ideal for field deployment in remote and resource-limited environments.

[0009] Such a multifunctional water purification device can provide safe drinking water in minutes, with high reliability and minimal maintenance, fulfilling a critical need for disaster relief agencies, military units, adventurers, and communities facing water scarcity or contamination crises.

[0010] Summary of the Invention.

[0011] The invention provides a portable, hollow cylindrical water purification device comprising three vertically stacked compartments, each performing a different purification stage. The lower compartment contains a sediment filtration system to remove large particles and suspended solids. The middle compartment contains an activated carbon filter for adsorption of chemical contaminants and improvement of taste and odor. The upper compartment contains a IIV-C sterilization unit powered by a small, manually operated generator or a solar-powered system, designed to inactivate bacteria, viruses, and other pathogens. The rotation speed of the IIV-C cylinder is adjustable by varying the electrical current, allowing optimization of exposure time for different water conditions.

[0012] Description

[0013] The device combines two advanced purification mechanisms — electrocoagulation and photocatalytic oxidation — within a single cylindrical unit, enabling the removal of a broad spectrum of contaminants in a single pass.

[0014] The electrocoagulation stage utilizes sacrificial electrodes, typically made of aluminum or iron, to release multivalent cations (Al3+or Fe3+) into the water under a low-voltage direct current (1). These ions rapidly hydrolyze to form amorphous metal hydroxide flocs with a high surface area, which adsorb and enmesh fine particulates, colloidal organic matter, and dissolved heavy metals through charge neutralization and sweep flocculation (2). The electrochemical reactions occurring at the anode and cathode can be represented as follows (for an aluminum electrode) (3):

[0015] At the anode:

[0016] Al Al3++ 3e“

[0017] In aqueous solution:

[0018] Al3++ 3H2O AI(OH)3(S) + 3H+

[0019] At the cathode:

[0020] 3H2O + 3e-3 / 2H2(g) + 3OH“

[0021] The resulting in situ-generated coagulants are highly effective at removing pathogens, natural organic matter (NOM), arsenic, fluoride, and even certain pharmaceuticals (4). Importantly, this process eliminates the need for chemical coagulant storage and dosing, a major advantage in field applications (5). Following electrocoagulation, the water enters the photocatalytic oxidation stage, which is designed to destroy residual organic pollutants and microbial contaminants at the molecular level. The stage employs a photocatalyst, preferably titanium dioxide (TiO2) in anatase form, immobilized on an inert substrate to prevent release into the treated water. When irradiated by IIV-A or IIV-C light (wavelengths between 254-365 nm), the TiO2surface undergoes electron-hole pair generation:

[0022] TiO2+ hv e-(CB) + h+(VB)

[0023] The photogenerated holes (h+) oxidize surface-bound hydroxyl groups or water molecules to produce highly reactive hydroxyl radicals (*OH), while the electrons (e~) reduce dissolved oxygen to generate superoxide anion radicals (O2*“) (6). These reactive oxygen species (ROS) initiate a cascade of oxidative reactions capable of mineralizing a wide range of persistent organic pollutants, including pesticides, volatile organic compounds (VOCs), dyes, and pharmaceutical residues, ultimately converting them to carbon dioxide, water, and inorganic ions. Simultaneously, oxidative stress damages microbial cell membranes, disrupts enzyme function, and degrades genetic material, leading to the complete inactivation of pathogens without the use of chemical disinfectants (7).

[0024] The combination of electrocoagulation and photocatalytic oxidation in a sequential flow path creates a synergistic effect: electrocoagulation removes bulk contaminants and reduces turbidity, thereby enhancing UV light penetration and increasing photocatalytic efficiency; conversely, photocatalysis oxidizes residual organics that might otherwise foul the electrocoagulation stage. The multi-stage cylindrical geometry ensures compactness, optimized flow distribution, and easy integration of these processes without the need for complex pumps or pressurization systems. By uniting these complementary mechanisms within a portable, power-independent device, the present invention provides a highly effective solution for producing microbiologically and chemically safe drinking water in minutes, even under the most challenging field conditions. This device has three main parts, all placed inside one cylinder on top of each other. These parts are: the electrocoagulation section, the photocatalytic section, and the clean water storage section. Each part is explained below.

[0025] Electrocoagulation Section

[0026] The top part of the cylinder is the electrocoagulation section. In this section, two electrodes made of graphite, iron, or aluminum are installed and connected to a battery. When the electric current flows, the electrolysis of water begins. This process releases trivalent iron ions (Fe3+) or trivalent aluminum ions (Al3+) if iron or aluminum electrodes are used. These ions act as strong coagulants. If graphite electrodes are used, the electrical treatment still happens, but no strong coagulants like Fe3+or Al3+are produced, so the treatment efficiency is lower. The anode and cathode electrodes are installed at the bottom of this section. These electrodes can cause water electrolysis, producing very small oxygen and hydrogen bubbles. The bubbles attach to suspended particles in the water, helping them to float. During electrocoagulation, some impurities settle to the bottom, while others float to the surface. Therefore, the treated water outlet is placed at two-thirds of the section’s depth (see Figure 1). After this stage, the water flows into the second section, the photocatalytic section, for further treatment.

[0027] Photocatalytic Section

[0028] The photocatalytic section contains a tube made of polytetrafluoroethylene (PTFE). The inner surface of this tube is coated with nano-sized TiO2particles. This material allows light, especially ultraviolet (UV) light, to pass through it. Inside this section, there is a low-power UV LED lamp. The PTFE tube is wrapped around the UV lamp to receive the maximum possible light energy. The inner wall of the PTFE tube is covered with a thin layer of TiO2. When UV light shines on the TiO2surface, it excites the photocatalytic property of TiO2. As water passes through this layer, the organic compounds in the water are oxidized. This process reduces water pollution, and cleaner water comes out from the other side.

[0029] Clean Water Section

[0030] In this part, the treated water is collected and becomes ready for use. Advantages

[0031] This design offers several benefits:

[0032] • Multi-stage purification in a single portable unit ensures removal of sediments, chemicals, and pathogens.

[0033] • Compact and lightweight, ideal for outdoor and emergency scenarios.

[0034] • No external electricity required, as the device can operate via a hand crank or solar panel.

[0035] • Adjustable sterilization speed for different water quality levels via changing the voltage of electricity and residence tiem.

[0036] • Durable and reusable for multiple uses.

[0037] Brief Description of Drawings

[0038] Figure 1 : the schematic of the suggested purification system

[0039] References:

[0040] 1. Govindan K, Raja M, Maheshwari Sil, Noel M, Oren Y. Comparison and understanding of fluoride removal mechanism in Ca2+, Mg2+ and AI3+ ion assisted electrocoagulation process using Fe and Al electrodes. Journal of Environmental Chemical Engineering. 2015;3(3):1784-93.

[0041] 2. Yasri N, Hu J, Kibria MG, Roberts EP. Electrocoagulation separation processes. Multidisciplinary Advances in Efficient Separation Processes: ACS Publications; 2020. p. 167-203.

[0042] 3. Shih Y-J, Chien C-WC. Binary sacrificial anodes using transition metals (M+ Fe, M= Ni, Cu, Zn) for electrocoagulation of boron and recovery of magnetic spinel oxides. Chemical Engineering Journal. 2023;461 :142148.

[0043] 4. Alazaiza MY, Albahnasawi A, Ali GA, Bashir MJ, Nassani DE, Al Maskari T, et al. Application of natural coagulants for pharmaceutical removal from water and wastewater: a review. Water. 2022; 14(2): 140.

[0044] 5. Kabda§h I, Arslan-Alaton I, Olmez-Hanci T, Tunay O. Electrocoagulation applications for industrial wastewaters: a critical review. Environmental Technology Reviews. 2012;1 (1):2-45.

[0045] 6. Nosaka Y, Nosaka AYJCr. Generation and detection of reactive oxygen species in photocatalysis. 2017; 117(17): 11302-36.

[0046] 7. Kashef N, Hamblin MR. Can microbial cells develop resistance to oxidative stress in antimicrobial photodynamic inactivation? Drug Resistance Updates. 2017;31 :31-42.

[0047] 8. Gendeshmin SB, Seyedin SH, Dowlati M. Drinking water supply for communities affected by natural disaster emergencies: a qualitative study. BMC Emergency Medicine. 2025;25(1):70.

[0048] 9. Almeida-Naranjo CE, Gallegos E, Dominguez E, Gutierrez P, Valle V, Aguilar AD, et al. From renewable biomass to water purification systems: oil palm empty fruit bunch as bio-adsorbent for domestic wastewater remediation and methylene blue removal. Water. 2023;15(23):4116. 10. Yusuf K, Murtala M, Technology. Development and performance evaluation of a portable household ceramic water filter with activated carbon and magnetic treatment unit. International Journal of Environmental Science and Technology. 2020;17(9):4009-18.

[0049] 11. Liu H, Zhao X, Qu J. Electrocoagulation in water treatment. Electrochemistry for the Environment. Germany: Springer; 2009. p. 245-62.

[0050] 12. Pelaez M, Nolan NT, Pillai SC, Seery MK, Falaras P, Kontos AG, et al. A review on the visible light active titanium dioxide photocatalysts for environmental applications. Applied Catalysis B: Environmental. 2012;125:331-49.

[0051] 13. Ribao P, Corredor J, Rivero MJ, Ortiz I. Role of reactive oxygen species on the activity of noble metal-doped TiO2 photocatalysts. Journal of hazardous materials. 2019;372:45-51.

[0052] 14. Xie Z-H, He C-S, Zhou H-Y, Li L-L, Liu Y, Du Y, et al. Effects of molecular structure on organic contaminants’ degradation efficiency and dominant ROS in the advanced oxidation process with multiple ROS. Environmental science technology. 2022;56(12):8784-95.

[0053] 15. Bono N, Ponti F, Punta C, Candiani G. Effect of UV irradiation and TiO2- photocatalysis on airborne bacteria and viruses: an overview. Materials. 2021 ;14(5):1075.

Claims

Claims1 A water treatment device comprising:• an electrocoagulation unit positioned at the upper section of a cylindrical housing, the electrocoagulation unit including at least two electrodes selected from the group consisting of graphite, iron, and aluminum, connected to a power source, wherein the application of an electric current induces electrolysis of water to generate microbubbles of oxygen and hydrogen, and in the case of iron or aluminum electrodes, trivalent iron or aluminum ions are released to facilitate coagulation and flocculation of suspended solids;• a photocatalytic unit positioned downstream of the electrocoagulation unit, comprising a polytetrafluoroethylene (PTFE) tube with an inner surface coated with TiO2nanoparticles, the PTFE tube being arranged around a LIV-LED light source to maximize ultraviolet light exposure, wherein irradiation activates the TiO2photocatalyst to oxidize organic compounds present in the water; and• a treated water storage unit located downstream of the photocatalytic unit for collection of purified water.2.- The water treatment device of claim 1 , wherein the water outlet of the electrocoagulation unit is located at approximately two-thirds of the height from the bottom of said unit to allow separation of floated and settled impurities before entering the photocatalytic unit.3.- The water treatment device of claim 1 , wherein the photocatalytic unit employs a TiO2coating with an anatase crystal phase to enhance photocatalytic efficiency under UV- LED irradiation.4.- The water treatment device of claim 1 , wherein the LIV-LED light source operates at a wavelength in the range of 365-395 nm to optimize TiO2photocatalytic activation.5.- The water treatment device of claim 1 , wherein the electrocoagulation electrodes are configured in a parallel plate arrangement to increase contact surface area and enhance ion release.6.- The water treatment device of claim 1 , wherein the device operates as a fully integrated vertical system combining flotation, sedimentation, and photocatalytic oxidation in a single compact cylindrical housing.

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