A water filter device for filtering water for supply, consists of an outer housing, a general water inlet through the housing, a mechanical filter within the housing, a carbon filter within the housing and a general water outlet through the housing, the filter device providing a flow path from the general water inlet, through the mechanical filter and the carbon filter to the general water outlet. The water filter device further includes a secondary water inlet through the housing between the mechanical filter and the carbon filter, to provide a second flow path from the secondary water inlet through the carbon filter to the general water outlet, the second flow path thus bypassing the mechanical filter.

A water filter device for filtering water for supply, consists of an outer housing, a general water inlet through the housing, a mechanical filter within the housing, a carbon filter within the housing and a general water outlet through the housing, the filter device providing a flow path from the general water inlet, through the mechanical filter and the carbon filter to the general water outlet. The water filter device further includes a secondary water inlet through the housing between the mechanical filter and the carbon filter, to provide a second flow path from the secondary water inlet through the carbon filter to the general water outlet, the second flow path thus bypassing the mechanical filter.

Transportable wastewater treatment systems and wastewater treatment methods are provided, which employ a clarification unit. to treat. highly polluted wastewater (e.g., with BODs over 400mg/l and up to 1500mg/l) with a small footprint and without elaborate infrastructure or even without grid-based energy sources. The clarification unit comprises an anaerobic digestion unit configured to receive influent and reduce an organic load thereof to yield a first stream, an aerobic anoxic air lift reactor configured to treat the first stream and further reduce the organic load thereof to yield a second stream, and an aerobic unit configured to clarify the second stream and deliver effluent., the aerobic unit. comprising a plurality of vertical sheets configured to support growth of algae on biofilm, a sprinkling system configured to sprinkle the second stream onto the vertical sheets, and an organic matter removal unit configured to collect organic mass falling off the vertical sheets.

Described are methods for monitoring marine water-body sustainability at a site of discharge of water into the water-body. Typically, the discharge of water occurs at a discharge of streams, rivers, water purification plants, water desalination plants, power plants, and discharge of oil refineries. The methods provide for daily, quarterly, as well as annual monitoring of water-body quality to ensure sustainability. The methods typically include establishing monitoring sites at a plurality of designated distances from the site of discharge, at a plurality of designated depths at the monitoring sites, and obtaining samples from the water-body at the monitoring sites. Interrogating the obtained samples for physical and chemical monitoring, biological monitoring, biochemical and organic monitoring, microbial monitoring, and phylogenetic analysis, as well as monitoring the sites for marine observational surveys, helps establish the marine water-body sustainability at a site of discharge.

In one aspect, a modular filter assembly for filtering fluid that flows in a flow direction therethrough is disclosed. The assembly includes a first housing section having a first filter element; a second housing section having a second filter element; and a connector disposed between the first and second housing sections. A housing includes the first housing section, the connector, and the second housing section. The flow direction is through the first and second filter elements in series.

A water treatment device comprising a clear container with lid surrounded by a solar reflector, and an insert in the form of a thin sheet or mesh permanently coated with titanium dioxide as a water sanitizing catalyst. The container is filled with non-potable water, covered with the lid, and placed in direct sunlight. Direct and reflected sunlight enters the water through the clear container and lid, where the sunlight's ultraviolet (UV) radiation and increased solar thermal heat disinfect the water. Further, the catalyst on the insert reacts with dissolved oxygen in the water to produce reactive oxygen species. These reactive species react with and decompose organic compounds in the water, and kill or inactivate pathogens. In addition, the reactive oxygen species further react with the water itself to produce additional free radical species, which also react with and decompose organic compounds and kill or inactivate pathogens.

A household water purifier includes a main unit and a filter assembly arranged in the main unit. The filter assembly includes a composite filter core. The composite filter core includes a filter bottle and a filter element located in the filter bottle. The filter element is of a separated structure. In the household water purifier, the filter element is located in the filer bottle; during use, when the filter element needs to be replaced, the filter element can be directly taken out of the filter bottle for replacement; Furthermore, the filter element itself is of a split structure. It is no need to replace the filter element as a whole, just some failed components of the filter element need to be replaced, which further improves convenience of replacement and maintenance of the filter core of the water purifier, and saves maintenance and use costs of the water purifier.

A dual-purpose household water purifier includes a main unit and an expansion unit which can be detachably connected. When the main unit is connected with the expansion unit, a booster pump can pressurize tap water entering a filter assembly. In the dual-purpose household water purifier, the main unit can be used as a non-electric drive water purifier. After the tap water enters the filter assembly and is filtered. The purified water flows into the purified water chamber of the pressure bucket, and the user takes the purified water. It is further provided an expansion unit. When the main unit is connected to the expansion unit, the booster pump can pressurize the pipeline, reducing application environmental restrictions on the water purifier. Through arrangement of the expansion unit, the water purifier can be operated in two operation modes of non-electric drive mode and electric drive mode.

A method of reducing leakage current from a patient to a ground potential through an applied part of a medical device includes defining a maximum permissible leakage current A.sub.max from the patient to the ground potential when the patient is energized to an electric potential V and supplying the medical device with water having a resistivity value ρ through a fluid line having a length L and an inner diameter ID. The value of L and ID is selected to cause the fluid conduit filled with water of resistivity ρ to have a resistance of R high enough to maintain the leakage current from the patient to the ground potential below A.sub.max.

A filtration system for a pet water fountain is provided. The filtration system utilizes a pump placed within or along a watering bowl. The water filtration system also utilizes a multi-stage filtering device. In one aspect, the multi-stage filtering device includes a first filtering stage representing copper zinc alloy particles, and a second filtering stage representing granulated activated carbon particles. Each stage may constitute filtering material that is separated into an array of cells residing along a vertical frame or is separated into stages placed in series within a tubular cartridge. A method for filtering water in a pet fountain is also provided herein.