{
    "title": "Solvatten Water Purification System",
    "inventor_name": "Petra WADSTROM",
    "publication_year": 2007,
    "device_name": "Solvatten",
    "goal": "Provide safe drinking water by disinfecting contaminated water using solar energy.",
    "problem_addressed": "Lack of reliable drinking water and electricity in developing regions, leading to water-borne diseases.",
    "concept_summary": "A portable 10-liter container with a transparent solar-permeable side and a black UV-absorbing side. Sunlight heats the water above 60  deg C while UV radiation inactivates microbes; built-in filters remove particulates. An indicator shows when the water has reached a safe temperature.",
    "detailed_description": null,
    "category": "Thermal Systems",
    "principles": [
        "Solar heating",
        "Ultraviolet radiation",
        "Physical filtration"
    ],
    "scientific_domains": [
        "Environmental Engineering",
        "Public Health",
        "Materials Science"
    ],
    "mechanisms_of_action": [
        "Heating water above 60  deg C for pasteurisation",
        "UV-induced microbial inactivation",
        "Mechanical removal of larger particles by filter elements"
    ],
    "materials": [
        "Transparent plastic (UV-permeable)",
        "Black plastic or coating (absorbing layer)",
        "Filter media (cloth, mesh)"
    ],
    "energy_sources": [
        "Sunlight"
    ],
    "inputs": [
        "Contaminated water",
        "Sunlight"
    ],
    "outputs": [
        "Purified drinking water"
    ],
    "claimed_performance": "Treats 10 L of water in 3-4 hours, reaches >=55  deg C, meets WHO standard of <1 CFU/100 mL, can save up to 2 500 kg firewood per year.",
    "experimental_evidence": "Trial in Nepal demonstrated that the device can sterilise water after several hours of sun exposure; WHO standard compliance claimed by inventor.",
    "replication_status": "Patent granted (US2007262010) and field trials reported; no independent large-scale replication documented.",
    "keywords": [
        "Solar water purification",
        "UV disinfection",
        "Portable water filter",
        "SODIS",
        "Renewable energy"
    ],
    "related_technologies": [
        "Solar water disinfection (SODIS)",
        "Solar stills",
        "Passive solar heating"
    ],
    "controversy_level": "low",
    "confidence_score": 0.9,
    "practicability_score": 0.8,
    "fringe_score": 0.1,
    "evidence_strength": 0.6,
    "risk_score": 0.1,
    "trl_estimate": 7,
    "source_urls": [
        "http://www.newscientist.com/blogs/shortsharpscience/2009/01/solar-power-might-become-big.html",
        "http://www.solvatten.se/SOLVATTEN/Start.html",
        "http://v3.espacenet.com/publicationDetails/biblio?KC=A&date=20071107&NR=101068578A&DB=EPODOC&locale=en_EP&CC=CN&FT=D",
        "http://www.youtube.com/watch?v=IWTz9SAXNik"
    ],
    "organizations": [
        "SOLVATTEN AB"
    ],
    "applications": [
        "Rural drinking water supply",
        "Emergency and disaster relief",
        "Off-grid households"
    ],
    "limitations": [
        "Ineffective in rain or prolonged cloud cover",
        "Requires several hours of direct sunlight",
        "Limited to small batch volumes (~=10 L per cycle)"
    ],
    "open_questions": [
        "Long-term durability of the plastic container under UV exposure",
        "Effectiveness against viral pathogens",
        "Scalability and cost for mass distribution"
    ],
    "red_flags": [],
    "evidence_quotes": [
        "Simply pour several litres of water into its two tanks, leave it in the sun for a few hours and collect the sanitised drinking water. An indicator signals it is safe to drink once the temperature inside has reached 55  deg C.",
        "The container comprises a first surface that is formed of a permeable layer for sunlight and a second surface that is formed of an absorbing layer for sunlight.",
        "The water in the container has been heated to a temperature of at least 60  deg C after exposure by sunlight and also exposure of ultraviolet radiation in order to make it possible to kill undesired micro-organisms.",
        "If SOLVATTEN is used once a day during 250 days in a year, you can save 2 500 kg of firewood. That means less soil erosion and saves a large amount of CO_2.",
        "The device works even on cloudy days, although it can take up to 6 hrs to reach temperature. It doesn't work at all when it's raining."
    ]
}