Water Tech Library

The tank is constructed by forming a cylindrical cage from 14-gauge welded wire mesh, lining it with asphalt felt for puncture resistance, and placing a 4-mil black Visqueen plastic liner inside to hold water. The liner is pleated and weighted with sand, creating a flexible, impermeable basin that relies on gravity and ground support.

Greywater flows through a sludge tank to settle solids, then passes through four 500L IBC tanks arranged at a height to allow gravity flow. Each tank contains a reed bed that biologically breaks down organic pollutants (COD reduced to 20-100 mg/L, DO > 2). Two small 0.25 HP pumps circulate water as needed. Treated water is stored in a 1000L IBC tank.

Rainwater is collected from roofs or catchments and conveyed to an underground storage tank. The tank is constructed with cement-soil plaster (ratios 1:8 for anthill soil, 1:3 for sandy soil) over a reinforced excavation. Water is extracted via a pump or bucket, with minimal evaporative loss due to underground placement.

Water enters through a diffuser plate to prevent disturbance of the biological layer (schmutzdecke) at the sand surface, where predators consume pathogens; subsequent passage through fine sand and gravel provides mechanical filtration and adsorption.

Sensor analog and digital outputs are connected to an Arduino Uno core controller that continuously samples pH, temperature, and turbidity. Processed data is communicated wirelessly (with Zigbee mentioned as an option) to a centralized monitoring platform, while onboard LEDs deliver immediate local status indication for field operators without needing a screen or smartphone.

MOFs with high surface area and strong water affinity adsorb water vapor from ambient air. When exposed to sunlight or slight temperature increase, the water is released and condensed, requiring no active cooling or heating beyond ambient energy.

The ram pump uses the kinetic energy of flowing water to create a cyclic water hammer. An impulse valve opens to let water flow, then closes rapidly when velocity builds, forcing water through a delivery valve into an air chamber. The pressurized air expels water through the delivery pipe, and the cycle repeats automatically.

Bamboo poles serve as beams and columns in a structural frame. The bahareque system uses a bamboo-reinforced cement plaster matrix for shear walls, providing stiffness and earthquake resilience. Connections are bolted or tied, and foundations are concrete. The design follows ISO 22156 and national standards for structural safety.

Zeolite performs ion exchange to capture heavy metals and ammonia, while biochar’s porous pyrolyzed-carbon structure adsorbs organic pollutants and supports colonization of beneficial microbes that biodegrade certain contaminants.

Biopolymers such as alginate, chitosan, or cellulose are doped with metal-oxide nanoparticles (e.g., ZnO, TiO2) or graphene oxide to form composite hydrogels or membranes. The biopolymer matrix adsorbs contaminants via chelation and electrostatic interactions, while embedded nanoparticles provide photocatalytic degradation under UV or visible light.

The black crocheted structure absorbs sunlight and converts it to heat. Water wicks through the hydrophilic yarn and evaporates from the heated surface, while contaminants remain in the bulk water. The condensed vapor is collected as purified water.

Gravity-fed water first passes through a gravel roughing filter to remove turbidity, then a slow sand filter for pathogen reduction via biological activity, and finally a biochar contactor for adsorption of chemical contaminants (pesticides, pharmaceuticals, heavy metals). An inlet float valve controls flow and maintains water levels.

Rainwater is collected from rooftops or surface runoff and stored in a brick-walled tank lined with cement plaster. The tank is constructed with reinforced brickwork and a waterproof cement render, preventing leakage and evaporation.

The system generates a stabilized bubble-film interface that selectively concentrates and extracts dissolved contaminants from water via interfacial adsorption and foam separation physics. Contaminants are trapped at the liquid-gas boundary of fine bubbles and removed as a concentrated foam fraction, reducing the need for high-pressure pumps or chemical coagulants.

Provides design methods and experimental data for hydraulic structures such as spillways, stilling basins, and pipe outlets. Many documents focus on energy dissipation, cavitation, and flow control.

Water poured into the filter slowly percolates downward through a biologically active ‘schmutzdecke’ layer at the fine sand surface and subsequent sand bed. Mechanical straining, predation, adsorption, and natural biological processes in the established biofilm work together to reduce bacteria, protozoa, and turbidity using only gravity.

Contaminants adhere to the outer and inner surfaces of multi-walled or single-walled carbon nanotubes through physisorption (van der Waals forces) and chemisorption (surface functional groups). The high aspect ratio and large specific surface area of CNTs provide abundant binding sites for metal ions, organic compounds, and other pollutants, enabling efficient removal even at low concentrations.

A specially formulated cementitious binder is mixed with local soils, rock, or industrial by-product aggregates and compacted in lifts to form a structural embankment or wall. The binder chemically stabilizes the matrix, achieving low permeability and sufficient shear strength to resist hydraulic pressure without relying solely on standard Portland cement concrete.

The clay pot, fired with sawdust to create porosity, physically strains out bacteria and suspended solids via mechanical entrapment. Copper mesh placed in the receptacle releases copper ions that disrupt bacterial cell membranes, providing a secondary disinfection step against remaining coliforms.

During high-temperature firing (900–1000°C / 1650–1830°F), the organic burnout material combusts completely, leaving behind an interconnected network of microscopic pores (0.6–3.0 microns) throughout the ceramic body. Water percolates through these pores via gravity; pathogens, cysts, and suspended solids are physically trapped because they exceed the pore throat size. A post-firing colloidal silver treatment (20–50 ppm) adsorbs to the internal pore surfaces, providing a secondary bactericidal mechanism by disrupting microbial cell membranes and preventing biofilm growth.

Water flows through the ceramic pot by gravity. Physical filtration occurs when pores (0.6-3.0 µm) trap bacteria and protozoa. Colloidal silver coating provides additional antimicrobial action by disrupting pathogen cell membranes. Adsorption on clay surfaces also helps remove some contaminants.

The membrane uses layered graphene oxide sheets that create nanochannels. Water passes through while larger contaminants (e.g., natural organic matter, pathogens) are blocked. The antifouling nature of graphene reduces biofilm formation, and membrane operates via low-pressure crossflow filtration.

A three-dimensional fine-mesh polypropylene net (similar to Raschel) is suspended in a steel frame, backed by a geogrid for stability. Fog droplets impact and coalesce on the mesh, drip into a gutter, and are piped to storage. Rubber expanders maintain tension and act as predetermined breaking points during extreme wind events.

These tanks are made from food-grade, UV-stabilized polyethylene using rotational molding for seamless, leak-proof construction. They are buried underground, collecting rainwater via a downspout or being filled by truck. Water is extracted using a submersible or external pump.

Water passes slowly through a bed of sand where a biological layer (schmutzdecke) forms, trapping particulates and digesting pathogens. Cleaning is done by scraping the top layer of sand rather than backwashing.

Water is applied at a low hydraulic loading rate (0.1–0.4 m/h) to the surface of a fine sand bed (effective size 0.15–0.35 mm). A gelatinous biofilm layer called the schmutzdecke naturally develops within 1–3 weeks, biologically digesting organic matter and pathogens while the underlying sand provides physical straining and adsorption. Treated water is collected by an underdrain system beneath a supporting gravel layer.

Water passes through graded layers of gravel and fine sand (effective size 0.15–0.35 mm). A gelatinous biological layer called the schmutzdecke forms on the sand surface after a 1–3 week maturation period, where microorganisms degrade organic matter and pathogens. Physical straining, sedimentation, and adsorption remove turbidity and particulates, while recent biochar amendments add adsorptive capacity for certain dissolved organic contaminants.

Provides hydraulic design procedures, geotechnical investigation requirements, and construction specifications for gravity and pressure pipe systems. Focus on pipe material selection, joint design, thrust restraint, and corrosion control.

Water flows by gravity through a sand layer where a biofilm (schmutzdecke) develops; particulates are trapped and pathogens are reduced through biological processes. Requires rough container walls to prevent channeling.

Rainwater is collected from a roof via gutters and downspouts, then directed into an excavation lined with billboard vinyl sheets. The vinyl acts as a waterproof barrier, and the surrounding earth provides structural support and thermal insulation. A timber framework covers the top, with a vent to prevent condensation and a manhole for access.

Contaminated water percolates through a bed of highly porous biochar created by heating wood, agricultural waste, or coconut shells in a low-oxygen environment (pyrolysis). The biochar’s vast internal surface area traps impurities via physical adsorption and ion exchange, binding organic compounds and some heavy metals while gravity drives flow without pumps or electricity.

Water flows by gravity through a layered column of coarse rocks, gravel, fine sand, and biochar. Biochar adsorbs organic contaminants and some heavy metals, while sand and gravel trap suspended particles and provide a medium for microbial biofilm formation that aids pathogen removal.

Raw water percolates slowly downward (0.1–0.4 m/h) through a 1–2 meter bed of fine sand. A naturally forming gelatinous biological layer on the surface consumes and predates pathogens, while underlying sand performs physical straining, depth filtration, and adsorption onto grain surfaces. The system functions entirely by gravity and matures biologically over an initial ripening period.

Precast reinforced concrete rings are stacked in an excavated cylindrical pit and sealed internally with waterproofing mortar to prevent exfiltration and groundwater infiltration. Rooftop runoff is gravity-fed through piping into the cistern; a submersible electric pump provides pressurized extraction for household use.

The tank is formed around an armature of rebar and multiple layers of galvanized chicken wire and electro-welded mesh (typically 2 layers chicken wire, 1 welded mesh, 2 layers chicken wire). Portland cement mortar is slapped onto both sides of the mesh and cured under tension—often with perimeter tie wires to prevent buckling—creating a thin-shell (~2 in / 5 cm), crack-resistant composite. A domed roof can be added using wooden forms to create a fully enclosed cistern.

A 1 m x 1 m square of polypropylene mesh is stretched over a copper pipe frame, supported by galvanized conduit posts. Fog droplets captured on the mesh drip into a folded galvanized sheet metal trough, which channels water into a bucket or cistern via gravity. Cable bracing and rebar stakes provide wind stability.

Water passes through successive layers: gravel traps large debris, sand captures finer particles, and activated charcoal adsorbs organic compounds, some chemicals, and odors via its porous structure. A cloth layer at the bottom prevents material loss.

Water flows from a higher source through a drive pipe and out an open waste (impulse) valve. As flow velocity increases, drag lifts the waste valve until it slams shut, suddenly arresting the water column and creating a water hammer pressure spike. This high-pressure pulse forces open a delivery check valve, pushing water into an air chamber/pipe, which smooths pulsations and lifts water up the delivery pipe. The pressure then drops, valves reset by gravity, and the cycle repeats indefinitely.

Rainwater from the roof is channeled into an underground reinforced concrete cistern, which is constructed as part of the building’s foundation. The 8x12x8 ft tank is built with rebar-reinforced concrete in three pours: floor, walls, and roof. The earth provides insulation and structural support.

Water flows by gravity through a vertical stack of progressively finer media: coarse gravel pre-filters large debris, fine sand physically traps suspended solids and reduces turbidity, and activated charcoal chemically adsorbs chlorine, volatile organic compounds, and odorants via its porous surface structure. The combined physical straining and adsorption mimics natural soil filtration processes.

Raw water percolates downward through sequential media: coarse gravel strains large debris, fine sand traps particulates, and activated charcoal adsorbs chlorine, volatile organic compounds, and odorous compounds via physical straining and surface adsorption.

A concrete mixture (1:3:5 cement/sand/gravel) is poured into forms to create a 12x12x6 ft tank. The tank is partially buried to equalize pressure and keep water cool. It is filled from a well via a submersible pump and gravity-feeds water to household and irrigation points through buried PVC pipes.

Rainwater is captured from rooftops via gutters and downspouts, screened to remove debris, directed through a first-flush diverter that discards the initial dirty runoff, and stored in a cistern or tank. Water can be used by gravity flow or pumped, and optionally treated for potable use.

Uses solar thermal collectors to boil saline water; the steam is condensed into distilled water, which is then remineralized. The process achieves zero liquid discharge by evaporating water and recovering salt via nanofiltration.

Linear Fresnel lenses concentrate sunlight onto a thermal evaporator surface. The collected heat drives evaporation of seawater, and an integrated heat exchange system recovers thermal energy from the condensing freshwater to preheat incoming saline feed, improving overall efficiency.

Earthen pots fabricated from clay and sawdust in varying ratios (50:50, 60:40, 70:30) are fired to create porous ceramic media. Raw water passes through the ceramic wall, which reduces turbidity and TDS by physical straining and adsorption. The water then contacts a copper mesh layer that acts as a disinfectant. Laboratory testing showed the 50:50 model removed up to 89% turbidity and 72.35% TDS from lake water, with complete elimination of E-coli across all models.

Analog and digital sensors feed parameter data into an ESP32 microcontroller, where a trained neural network processes the readings in real time to categorize water as ‘Normal’, ‘Rainwater Runoff’, or ‘Chemical’ with 99.28% accuracy. An intelligent fluctuation-based logging algorithm drastically reduces storage writes, and an automated pump control actuator enables autonomous response when anomalies are detected.

Electrical current is applied to water, causing the release of metal ions that neutralize the surface charge of viruses, allowing them to clump together and be easily removed. Simultaneously, the electric field inactivates the viruses, providing dual-action disinfection.

An electric current is applied to iron or aluminum electrodes submerged in water. The anode releases metal cations (e.g., Fe2+, Al3+), which neutralize charged particles and form metal hydroxides. These hydroxides act as coagulants, aggregating contaminants into flocs that float due to evolved hydrogen gas and are then removed by filtration or sedimentation.

Solar PV powers high-pressure pumps that force saline water through advanced reverse osmosis membranes. Energy recovery devices reclaim up to 70% of hydraulic energy from the brine stream. The modular, containerized package supports rapid deployment and daytime water production.

Solar panels generate electricity to drive high-pressure pumps; seawater is forced through reverse osmosis membranes. Isobaric pressure exchangers capture hydraulic energy from the brine stream and transfer it to incoming feedwater, reducing pump energy.

Seawater or brackish water undergoes reverse osmosis where a proprietary Energy Recovery Technology captures and reuses hydraulic energy from the high-pressure brine stream. This cuts energy consumption by up to 70% to under 3 kWh/m³, enabling the use of smaller, lower-cost solar PV arrays.

Finned electrode geometry increases active surface area and disrupts mass-transport limitations, accelerating the electrochemical release of metal ions under applied DC voltage. These ions generate hydroxide flocs in situ that adsorb surfactants (LAS), organic matter (COD), and turbidity from laundry wastewater.

A rapid-setting, low elastic modulus material is extruded in thin layers along the upstream dam axis to build the sidewall. This semi-elastic layer sits between the rockfill embankment and the concrete face slab, absorbing differential settlement and eliminating the need to trim over-placed cushion material to a precise slope.

Reinforced concrete dam sections are cast and cured under controlled factory conditions, then transported to the site for installation onto a prepared foundation. The modular units are assembled in place, creating a gravity or arch-type dam without traditional formwork and pouring, while maintaining structural integrity through post-tensioning or interlocking joints.

Successive layers of low-plasticity clay, clayey sand, and gravel are placed and compacted—by hand or light equipment—to form a gravity embankment. The dam retains water by virtue of the mass weight and reduced permeability of the compacted fill, while a simple spillway safely conveys excess flood flow around the structure.

Iron oxide nanoparticles coated onto the porous biochar matrix create active sites for ligand exchange and surface complexation, binding arsenic and other metalloids far more effectively than unmodified biochar or sand alone. Water passes through the modified media bed where contaminants are sequestered via combined adsorption and iron-driven redox reactions.

The cistern is built using a steel armature of welded wire and reinforcing bars, plastered with a rich cement-sand mortar (1:2 ratio). The mortar acts as waterproofing, while the steel handles tensile loads. The design includes an open-top or roofed option, with strength calculations based on hydrostatic pressure.

Ferrocement is a composite of cement mortar applied over a steel wire mesh framework. The resulting thin-walled structure is strong, waterproof, and can be molded into various shapes. Tanks are typically built on-site, requiring minimal skills and locally available materials.

The tank is built by layering cement mortar onto a framework of steel wire mesh and rebar, creating a thin, strong shell. After curing, the ferrocement structure forms a waterproof container that can store rainwater collected from roofs for domestic use.

Fog droplets impact on closely spaced vertical stainless steel or polypropylene wires (0.5-1 mm diameter, 2-3 mm spacing). Unlike mesh, the vertical geometry prevents droplet bridging and clogging; captured droplets coalesce and slide down the wires under gravity into a collection trough. The design mimics conifer needles to maximize capture while minimizing aerodynamic resistance.

Wastewater enters a bioreactor where microbial communities biodegrade organic matter. An integrated forward osmosis membrane then draws purified water from the mixed liquor into a concentrated draw solution using natural osmotic pressure rather than hydraulic pressure. The diluted draw solution is subsequently regenerated to recover clean water, combining biological treatment with lower-energy membrane separation.

Solar-powered autonomous surface vehicles distribute natural photocatalytic materials derived from discarded shellfish across water bodies. Sunlight activates the photocatalysts to generate reactive oxygen species that oxidize algal biomass and organic pollutants, while a digital twin optimizes robotic coverage and dosing in real time.

Solar photovoltaic panels power reverse osmosis units that filter salt and contaminants from seawater. The system includes battery storage for continuous operation and is designed for off-grid environments.

The membrane filters dyes through size exclusion and interlayer spacing, while MIL-88A(Fe) acts as a photocatalyst under visible light, generating reactive oxygen species that degrade adsorbed organic contaminants. This reduces fouling and enhances long-term performance.

GO membranes consist of stacked graphene oxide nanosheets with nanochannels that permit water permeation while blocking solutes based on size exclusion and electrostatic interactions. The interlayer spacing can be tuned to selectively reject ions and organic molecules, and functional groups enhance hydrophilicity and fouling resistance.

Water flows from a higher elevation source (spring or reservoir) through pipelines using gravity. The hydraulic grade line (HGL) is used to design pipe sizes and ensure positive pressure, while air valves at high points release trapped air to prevent airlocks.

Water flows from a higher elevation spring into a spring box, then through a transmission pipeline downhill to a storage tank. A break-pressure tank reduces pressure to prevent pipe damage. The system uses elevation drop (gravity) to generate flow, with pipe sizing optimized to manage friction losses.

Evacuated solar collectors provide heat to a Temperature-Swing Vapor Pump crystallizer. The thermal energy fractionally crystallizes salts from brines, enabling selective recovery of valuable minerals while producing clean water vapor.

Water flows from a higher source through a drive pipe, gradually closing a waste (impulse) valve. The sudden closure creates a pressure surge (water hammer) that forces a small portion of water through a delivery check valve into an air chamber, compressing the air. The compressed air then pushes the water up the delivery pipe, after which the waste valve reopens and the cycle repeats.

Standard hydraulic ram action: water flows down a drive pipe, builds momentum, and trips a waste valve. The resulting water hammer forces water through a check valve into an air chamber, which then delivers water to the livestock tank. A bicycle inner tube inside the pressure chamber prevents air loss.

Contaminated water is poured into the top reservoir and passes through a diffuser plate into a fine sand column (effective size 0.15–0.20 mm). A biological active layer (schmutzdecke) forms on the sand surface where microorganisms consume pathogens, while physical processes including mechanical trapping, adsorption, and natural predation occur throughout the sand bed. Filtered water exits via a drainage tube surrounded by supporting gravel layers that prevent sand from clogging the outlet.

Dirty water is gravity-fed through an inverted bottle funnel. Gravel and rice act as coarse pre-filters trapping large debris; cotton balls and coffee filters slow flow and capture fine particulates; sand layers physically strain smaller particles by size exclusion; and activated charcoal adsorbs certain dissolved chemicals and impurities, yielding visibly cleaner water.

A network of electrochemical and optical sensors is embedded within and around a passive filtration media bed. Sensor data is continuously acquired and analyzed to assess both raw water quality and filtration performance, triggering alerts or control actions that transform a static filter into an actively managed treatment node.

Sensor nodes measure parameters (pH, conductivity, turbidity, etc.) and transmit data wirelessly to a central platform. AI algorithms, such as AdaBoost, are trained on historical sensor data to predict non-sensor indicators (e.g., E. coli) by correlating them with physically measured variables, enabling proactive contamination alerts.

Rainwater collected from rooftops is stored in a tank positioned at a high elevation (e.g., on a roof or raised platform). Gravity provides sufficient pressure to distribute water to point-of-use taps without pumps. The tank is typically closed to prevent contamination and algae growth.

The tank is formed by plastering cement mortar over a wire mesh armature shaped as a jar. The curved geometry distributes stress evenly, while the thin shell (2-3 cm) minimizes material. Curing over three days ensures watertight integrity, and the design can be scaled up for larger storage.

Co-knitted stainless steel wire and polyester filaments form a robust, open mesh. Fog droplets impact on the metal fibers, coalesce, and drain by gravity. The metal construction resists UV degradation and provides physical strength, while the knit structure optimizes droplet capture and drainage.

The tank is built using a skeletal armature of steel reinforcement bars and welded wire mesh, which is then plastered inside and out with a thin layer of cement-sand mortar (~2 cm). The mortar waterproofs the structure, while the steel mesh provides tensile strength to resist hydrostatic pressure, creating a monolithic, leak-proof container.

Runoff from large roofs (e.g., warehouses, hangars) is captured and stored in below-ground fiberglass or concrete tanks. Water is filtered (e.g., 25 GPM skid) and disinfected (UV) before use. Systems are designed to manage stormwater peak flows and reduce potable water demand.

Black metal panels are etched with femtosecond lasers to create superwicking, ultra-light-absorbing surfaces. Solar radiation drives evaporation of a thin seawater film across the active region; salts and minerals crystallize on passive untreated sides via the coffee ring effect, preventing clogging and enabling continuous operation.

High-precision electrochemical probes wired to a Waspmote IoT board sample key chemical and environmental indicators at configurable intervals. Data is transmitted over LoRaWAN, 4G, or other protocols to a cloud platform, enabling continuous monitoring, automated alerts, and integration with digital-twin or compliance dashboards.

LID integrates site design principles (e.g., minimizing impervious cover) and stormwater control measures (e.g., bioretention, infiltration trenches) to reduce runoff volume and peak flow. Techniques rely on infiltration, evapotranspiration, and rainwater harvesting to mimic natural hydrology.

Clay powder is dry-mixed with uniformly sifted combustible material (typically 50:50 to 60:40 by volume) and water to form a plastic body. The mixture is molded into a frustrum-shaped pot and fired at 850–900°C, burning out the organic material and leaving a network of 0.6–3.0 micron pores. Water percolates through the ceramic wall under gravity, mechanically trapping bacteria, protozoa, and sediment. An optional colloidal silver coating disrupts microbial DNA to prevent biofilm growth and provide secondary disinfection.

Rooftop catchment channels rain through gutters and downspouts into a first-flush diverter, then into two connected 200-liter HDPE drums. Water is stored for non-potable uses like irrigation and washing, with overflow directed away from the foundation.

Seamless monolithic HDPE shell manufactured with FDA-compliant resins and UV inhibitors prevents chemical leaching and algae growth. External geometric ribbing distributes vertical soil and surface loads laterally, allowing stable empty burial without deep trenches or heavy ballast in most soil conditions.

Uses photovoltaic panels to directly power a reverse osmosis pump; the system's electronics continuously vary power consumption to match real-time solar irradiance, eliminating the need for energy storage.

A central "flow command-current control" module reads solar irradiance multiple times per second and dynamically adjusts the voltage applied to an ion-exchange membrane stack and the rate at which water is pumped through it. This real-time matching maximizes salt removal without energy storage.

A flow command-current control module samples solar intensity several times per second and synchronizes water pump flow and electrodialysis current. Salts are drawn through ion-exchange membrane stacks by electric potential, directly consuming up to 94% of generated PV power without energy storage.

Flat-packed fiberglass composite panels are bolted and gasketed together on a structural slab to form a non-pressurized atmospheric tank. The material resists internal hydrostatic loads and chemical corrosion without requiring soil-load engineering, enabling installation in basements, mechanical rooms, and retrofits.

Low-voltage DC current dissolves aluminum or iron anodes, releasing metal cations that neutralize the electrical charges of colloids and emulsified oils. The ions hydrolyze in situ to form metal hydroxide flocs that adsorb and enmesh contaminants, which then separate from the water via flotation or settling.

Rainwater is collected from rooftops (or a deployable catchment) and stored in flexible, food-grade plastic bags. The bags can be fitted with various attachments: a SODIS-compatible clear top for solar disinfection, a spigot for handwashing, or a drip irrigation connector.

Standard water hammer cycle: water flows down a drive pipe, an impulse valve closes automatically, sending a pressure wave through an air chamber to push water up the delivery pipe. A snifter valve introduces a small air bubble to maintain chamber pressure. The cycle repeats 20–100 times per minute.

The Janus-faced membrane floats at the water-air interface; carbon microstructures in the top layer absorb solar energy locally to drive evaporation, while the porous hydrophilic bottom layer continually draws saline water and rejects salt crystals back into the bulk water.

A simple salt (NaCl) solution extracts cationic coagulant proteins from Moringa seeds. When added to water, these proteins neutralize the negative surface charge of microplastics and other colloids, causing particle destabilization and aggregation into larger flocs. In an in-line filtration configuration, these flocs are captured directly by a downstream sand filter without requiring large sedimentation basins.

Cationic proteins in Moringa seeds (e.g., dimeric proteins of ~13 kDa) neutralize negatively charged suspended particles (clay, silt, microorganisms), causing them to aggregate into larger flocs. These flocs settle by gravity, allowing physical removal of turbidity and attached microbes, with salt extraction (e.g., NaCl) enhancing protein solubility and coagulation efficiency.

Positively charged, water-soluble proteins in the seed powder (such as Mo-CBP3-4) bind to negatively charged suspended particles—including clay, silt, organic matter, and bacterial cell surfaces—via electrostatic attraction. This charge neutralization reduces repulsive forces, causing impurities to aggregate into larger flocs that settle by gravity or are captured by simple filtration; seed proteins concurrently disrupt bacterial cell membranes.

Contaminated water percolates downward by gravity through progressively finer media. Gravel and coarse sand provide mechanical straining of large and fine particulates, while activated charcoal adsorbs dissolved organic compounds, chlorine, and odors via its high-surface-area pore structure.

Water passes through sequentially arranged filtration media layers, each stage targeting specific contaminant classes: particulate removal, chlorine reduction, and VOC adsorption. An optimized flow channel geometry ensures uniform distribution across the media bed, reducing pressure drop while maximizing contact time between water and the active filtration surfaces for consistent output.

The adsorbent material contains specialized nanoscale cages designed to act as selective traps that lock onto PFAS molecules via tailored chemical affinity. This enables effective capture of both long-chain and short-chain PFAS compounds from aqueous solutions, and the material demonstrates durability and sustained performance after multiple regeneration and reuse cycles.

Nanomaterials are synthesized into the membrane active layer or coated onto polymeric supports. CNTs create rapid water transport nanochannels; TiO₂/ZnO impart photocatalytic activity for degrading organics and controlling biofouling; MOFs provide high-surface-area adsorption sites. The resulting nanocomposite achieves higher permeation, better selectivity, and reduced fouling during pressure-driven filtration.

Nanoparticles incorporated into membrane materials physically block contaminants via tiny pores and chemically degrade pollutants through photocatalysis or adsorption. For example, titanium dioxide nanoparticles use UV light to oxidize organic pollutants.

Atomic-thickness graphene-oxide sheets are engineered with controlled nano-channels that allow rapid water permeation while blocking dissolved salts, organics, and microplastics via size exclusion and electrostatic repulsion. The hydrophobic/graphitic structure reduces fouling tendency compared to traditional polymer membranes.

Water flows through a channel where an electrical current generated by an integrated solar panel actively extracts dissolved salts and bacteria. This electrochemical approach eliminates the need for high-pressure pumps and fragile membrane filters used in conventional portable desalinators.

Water passes through a sand column where a biological layer (biolayer) forms; pathogens are removed via mechanical trapping, adsorption, predation, and natural death. The biolayer digests pathogens during a pause period between uses.

A solar-heat-driven reactor forces air through precision nozzles that vaporize saline water into a humid air stream. The stream is then dehumidified to capture fresh water, while dissolved solids precipitate out, achieving zero liquid discharge without membranes or electricity.

Oscillatory current or pulsed flow disrupts boundary layers at the electrode surface, mitigating passivation and enhancing collision rates between flocs and colloidal particles. Sacrificial iron or aluminum anodes release coagulant ions that form hydroxides, aggregating suspended solids and organic contaminants.

The spring eye is excavated and enclosed within a concrete or masonry box with a fitted cover. A catchment wall or cut-off wall directs water into the chamber while a diversion ditch prevents surface runoff ingress. Outlet pipes and overflow pipes manage flow and prevent backpressure.

Unlike traditional rams with external spring- or weight-loaded waste valves, the Papa Pump uses a patented Venturi valve arranged concentrically around the input pipe. The venturi effect manages pressure surges and water hammer with up to 95% less mechanical valve wear, eliminating hydraulic lock. This enables a strong, compact, inline configuration that pressurizes water into an air vessel and up the delivery line using only the source water’s kinetic energy.

Water flows through a ring-shaped elastomeric venturi valve that generates a low-pressure zone, causing rapid closure without heavy springs. The resulting pressure surge pushes water through an inline delivery check valve into a pressure vessel, which then expels water to the delivery line. The concentric design minimizes energy losses.

Raw water enters a coarse pre-filtration column (gravel and coarse sand) to remove large debris, then flows in series or parallel through subsequent columns containing finer sand and activated charcoal. This staged approach reduces head-loss and distributes sediment load to prevent rapid clogging of a single vessel.

Cisterns store runoff from impervious surfaces (rooftops, parking lots) and release it at a controlled rate or reuse it for indoor/outdoor purposes (e.g., toilet flushing, irrigation). Systems include inlet filters, overflow controls, and pumps. Sizing is based on water demand and storm frequency.

Silver nanoparticles are incorporated into a pine tree resin lining applied to handmade clay pottery. As water is poured through the pot, the silver particles inactivate bacteria. The pine resin coating was specifically engineered to prevent silver from reacting with waterborne chloride and sulfide compounds, which otherwise form a 'poison layer' that reduces silver disinfection efficacy. The materials and construction process cost less than $10 per unit.

Rainfall collected from roofs or runoff is directed into a dugout pit (5-10 m³) lined with 0.3-0.8 mm double-layer polyethylene. The liner prevents seepage, storing water for dry periods. Overflow is directed to a secondary pit or drainage.

Uses Manning’s equation for open channel flow in plastic pipes and provides roughness coefficients (n-values) for various pipe types. Also covers hydraulic grade line for culverts and energy dissipation.

Standard electrocoagulation chemistry is packaged into a transportable format where sacrificial iron or aluminum electrodes receive DC current to generate coagulant flocs in situ. Automated PLCs and app-based monitoring manage the process, while integrated flotation or settling chambers separate the flocs from treated water.

Terra‑cotta clay mixed with sawdust or rice husks is pressed into a bucket‑shaped vessel and fired at ~860°C, burning out the combustible to create pores. The filter is then coated with colloidal silver, which kills trapped bacteria. Gravity pulls water through the ceramic into a plastic receptacle with a spigot.

Reinforced concrete sections are joined with rubber or synthetic gaskets and sealant to create a watertight vessel. The concrete matrix maintains high internal alkalinity and excludes all light, creating a dark, cool environment that suppresses bacterial and algal proliferation, while allowing suspended particulates to settle.

Clay mixed with rice husks is pressed into a flower‑pot shape and fired at ~850°C, burning out the husks to create micropores. The fired pot is coated with colloidal silver, which deactivates bacteria by binding to their DNA. Gravity drives water through the porous ceramic into a clean receptacle.

Terracotta clay mixed with rice husks is pressed into filter elements using a hydraulic press. After firing at ~850°C, the combustible material burns out, leaving fine pores. Colloidal silver is painted on the fired filter to inactivate pathogens. Laterite clay is optionally added for virus binding.

Rainwater is collected from a catchment surface (e.g., roof), conveyed via gutters and downspouts through a debris filter, and stored in a cistern or tank. The stored water can be used directly (non-potable) or treated for potable use, reducing runoff and conserving water supplies.

Water is pre-dosed with coagulating/flocculating chemicals to aggregate fine particles into larger flocs, then pumped under pressure through a bed of coarser sand (typically 0.5–1.0 mm). Particulates are captured within the granular bed by direct interception, Van der Waals attraction, and surface charge mechanisms until periodic backwashing dislodges the solids.

Water flows through a multi-layer media bed (e.g., anthracite, sand, garnet) at 5-25 m/h. Filtration occurs via straining, sedimentation, and adsorption within the media depth. Filters are cleaned by backwashing with clean water.

IoT sensors on the physical plant stream operational data to a virtual replica running physics-based and data-driven models. The digital twin analyzes this real-time data to optimize process parameters—such as chemical dosing and pumping schedules—and predict maintenance needs, thereby reducing energy use and operational expenditure while maintaining water quality.

Low curved structures (approx. 30 cm high) built from local materials are placed alongside paved roads to intercept and spread runoff onto fields. Runoff can also be stored in borrow pits or ponds for later use, combining flood control and water harvesting.

Brick or stone walls are built with Roman cement (pozzolanic lime mortar) that sets underwater and creates a waterproof structure. The cistern is often capped with a vaulted brick roof, and the interior may be sealed with additional layers of Roman cement to prevent leakage.

Microbially contaminated water is filled into transparent PET bottles and exposed to full sunlight for at least 6 hours. Solar UV-A radiation damages pathogen DNA, while increased water temperature creates synergistic disinfection effects, inactivating bacteria, viruses, and some parasites.

UV-A solar radiation and thermal heating in transparent PET bottles damage pathogen DNA/RNA and accelerate microbial die-off. Water is oxygenated by shaking, then exposed horizontally to direct sunlight for a minimum of six hours (two days if cloudy).

Sunlight heats a saltwater chamber to produce vapor, which is channeled into a separate condenser. A resonant energy exchange mechanism stores and transfers thermal energy rhythmically, allowing the system to maintain production overnight without filters, membranes, or external electricity.

A concrete dam is built across a sandy riverbed; during rains, water flows downstream and sand accumulates behind the dam, storing water in the sand pores. Water is extracted via a pipe or well, naturally filtered by the sand.

The dam wall traps coarse sand carried by seasonal floods, forming an artificial aquifer. Water stored in the pore spaces of the sand is protected from evaporation and contamination, and can be abstracted via wells, scoop holes, or outlet pipes. The sand also provides natural filtration of pathogens and sediment.

Water percolates slowly through a bed of fine sand (0.15-0.35 mm effective size) at rates of 0.1-0.4 m/h. A biological layer called the schmutzdecke forms on the sand surface, trapping particles and degrading organic matter through microbial activity.

Clear plastic or glass bottles filled with contaminated water are exposed to full sunlight for at least 6 hours (or 2 days if cloudy). UV-A radiation and increased temperature work synergistically to inactivate bacteria, viruses, and protozoa.

A hygroscopic material (desiccant) absorbs moisture from ambient air. Solar thermal energy then drives desorption, releasing water vapor which condenses into a reservoir. The water is mineralized for taste and UV-treated for safety.

A spring box is constructed around the spring eye to channel groundwater into a collection chamber. Water flows by gravity through outlet pipes to a tap stand or storage tank; overflow and scour pipes prevent backpressure and allow sediment flushing. The sealed structure prevents surface contamination.

Wind drives fog through a vertically oriented double-layer Raschel polypropylene mesh (1 mm filaments, 35% shade coverage). Fog droplets impact the fibers, coalesce into larger drops, and fall by gravity into a collection trough or gutter, which channels the water via PVC pipe to a storage cistern. The process is entirely passive, relying on wind energy and gravity.

As stormwater flows through the vascular pore network of the wood biochar media, dissolved priority metals (copper, zinc) and organic pollutants adsorb onto carbon surfaces via surface complexation and ion exchange. Iron-doped variants add redox chemistry to target specific organic pollutants and dyes, increasing removal efficiency per unit volume over conventional sand/compost blends.

The unit combines multiple barrier treatment stages—typically filtration, membrane separation, and UV disinfection—within a weatherized, transportable enclosure. A hybrid renewable-energy architecture (solar/wind with battery backup) powers the pumps and controls, enabling autonomous operation on and off the electrical grid.

Starter dam built first, then raised progressively using tailings or borrow materials. Upstream dams rely on tailings for support (cheaper but less stable), downstream dams require more material but offer higher stability, and centreline dams maintain a fixed centerline for balanced performance. Internal drains and impervious cores control seepage and prevent liquefaction.

Lays out methodology for determining water demand (domestic, livestock, fire fighting), system losses, and pipe sizing using Hazen-Williams and Manning's formulas. Emphasizes economic pipe selection and life-cycle cost analysis.

The clay body provides microscopic channels that mechanically trap pathogens. An inner layer of activated carbon adsorbs organic chemicals, heavy metals, and odors. Nano‑silver coating acts as a bactericide, killing any bacteria that adhere to the filter surface.

Raw water passes sequentially through coarse gravel for structural support and large particulate removal, fine sand for trapping suspended solids and hosting beneficial bacteria, and a final charcoal layer for adsorbing organic compounds, heavy metals, and chemicals. Bacterial colonies established in the sand biologically displace and reduce pathogens without external energy.

Curved parabolic trough mirrors concentrate sunlight onto a receiver to generate heat. This thermal energy drives a forward osmosis process where water naturally passes through a semipermeable membrane without high-pressure pumps, reducing membrane fouling and energy demand.

Water flows by gravity from the top bucket through sand and gravel layers into the bottom bucket. A biological layer forms on the sand surface, removing pathogens and sediment through trapping and biological digestion.

La0.7Sr0.3MnO3 absorbs broadband solar radiation and converts it to heat at the evaporation surface. The inverse-L geometry continuously wicks water upward while gravity and the structure’s geometry channel precipitating salts away from the hot zone, preventing clogging.

Presents equations (Manning's, Bernoulli, energy, momentum) and design charts for gravity flow in pipes, culverts, ditches, and channels. Covers concepts like hydraulic grade line, critical flow, and hydraulic jumps.

Ultraviolet light triggers a photocatalytic reductive defluorination (PRD) reaction that systematically dismantles PFAS molecules. The process cleaves strong carbon-fluorine bonds and converts PFAS into benign end-products: water, fluoride ions, and simple carbon compounds.

A high-density polyethylene (HDPE) or fiberglass cistern is buried in an excavated pit. Rainwater is diverted from downspouts into the tank, and an electric submersible or jet pump delivers water to the use point. The tank is sealed to prevent contamination and buried to protect from sunlight and temperature extremes.

In one design, a trench is excavated across a natural groundwater or dry streambed path, a vertical impermeable barrier is inserted, and the trench is backfilled. In sandy terrain, a low masonry or concrete wall built across a valley traps coarse sand and water during floods; the accumulated sand layer overhead acts as an evaporative cap while storing water in the pore spaces below.

Uses elevation head (gravity) to provide pressure and flow. Pipe size and flow rate are matched using friction loss tables (e.g., Hazen-Williams formula) and the concept of hydraulic grade line (HGL) to ensure positive pressure and avoid suction.

Details criteria for horizontal and vertical alignment, hydraulic design (using Hazen-Williams and Manning's equations), and structural requirements for buried pipes. Standard details and specifications ensure consistent construction quality.

Guidelines for hydraulic modeling (including extended period simulation and water hammer analysis), pipe sizing using Hazen-Williams, and system reliability. Includes checklists for design submissions and technical references.

The system uses a refrigeration-based cooling condensation cycle: ambient air is drawn over cooling coils, condensing water vapor into liquid. The condensate is then filtered and treated to remove particulates and microbial contaminants, producing high-quality drinking water.