A perfusion bioprocessing system (10) includes a bioreactor (12) and a recirculation flow path (14) provided with at least one first feed flow control device (46) and at least one second feed control device (48). The perfusion bioprocessing system (10) further includes a first tangential flow filter (16) coupled to the bioreactor (12) via the recirculation flow path (14) and a second tangential flow filter (18) coupled to the bioreactor (12) via the recirculation flow path (14). The first tangential flow filter and the second tangential flow filter are coupled to a permeate flow path and a retentate flow path.

A device for measuring the pollution index of a filtration membrane includes: a raw water supply part; a first filtration membrane; a raw water supply line; a first flow rate measuring part; a first path line; a second path line; a second filtration membrane having a filtration characteristic different from the first filtration membrane; a first path selection valve installed in the first path line in parallel with respect to the second filtration membrane so that a first measuring path from the raw water supply part to the first flow rate measuring part passes through the first filtration membrane and a second measuring path from the raw water supply part to the first flow rate measuring part successively passes through the first and second filtration membranes; and a pollution index measuring part measuring the pollution indexes of the first and second filtration membranes.

Methods and systems for acid regeneration of ion exchange resins are disclosed. Acid resins designed for use in a variety of cleaning application using a water source use a treated, softened, acidic water source according to the invention. Various methods of using the softened acidic water generated by acid regenerate-able ion exchange resins are disclosed to beneficially reduce spotting, filming and scale buildup on treated surfaces, reduce and/or eliminate the need for polymers, threshold reagents and/or rinse aids, and using protons generated in the acidic water effluent for triggering events useful in various cleaning applications.

Methods of conditioning a membrane utilized for water purification are provided. The methods monitor membrane performance during water purification or membrane conditioning via fluorometric measurement. The monitoring allows for the detection of removal efficiency of the fluorescing substance. A conditioner is introduced in the feed stream to increase the detected removal efficiency of a fluorescing substance by the membrane. The conditioner generally extends the useful life of the membrane being conditioned.

A method for treating a swimming pool, including introducing Mg.sup.2+ to a level from 60 ppm to 300 ppm to the swimming pool by addition of a soluble magnesium compound to the swimming pool, or Mg.sup.2+ to a level from 60 ppm to 1000 ppm by addition of a magnesium halide in addition to a further soluble magnesium compound.

The present invention relates a method for early warning analysis of eutrophication of a designed artificial water body, comprising: establishing a three-dimensional model of the designed artificial water according to the data corresponding to a planning scheme of the water body, wherein the three-dimensional model of the designed artificial water body comprises at least the designed artificial water body and surrounding buildings; according to the three-dimensional model of the designed artificial water body, analyzing the designed artificial water body through an ecological simulation technology to obtain at least one of the analysis results including hydrological mobility, hydraulic retention time, algal community composition of source water, designed water depth, water body surface wind field, solar radiation and temperature of the designed artificial water body; and assessing the risk of eutrophication of the designed artificial water body according to at least one of the analysis results of the ecological simulation.

A system and method for backwashing a sand filter in a wastewater treatment system. In one aspect, the invention can be a system for backwashing a sand filter comprising: a sand filter configured to remove solids from an untreated wastewater; a container storing chlorine fluidly coupled to the sand filter by a chlorine supply manifold; a flow control mechanism positioned on the chlorine supply manifold between the container and the sand filter, the flow control mechanism alterable between a first position whereby chlorine cannot flow from the container to the sand filter and a second position whereby chlorine flows from the container to the sand filter, the flow control mechanism being biased into the first position; and a processor operably coupled to the flow control mechanism and configured to automatically actuate the flow control mechanism into the second position upon detecting that the sand filter is being backwashed.

A water purifier may include: a filter filtering raw water to provide purified water; a discharge port through which the purified water is discharged outside; water pipes providing a flow space for the purified water to flow; a flow path module including a body part supporting the water pipes; and a tubing assembly detachably connected to the water pipes to selectively open and close at least a portion of the water pipes when connected thereto. The tubing assembly has one side connected to the filter and the other side connected to the flow path module, and the flow path module receives the purified water filtered by the filter through the tubing assembly. The flow path module may be placed above the tubing assembly, and disposed between the filter and the discharge port while overlapping at least a portion of the tubing assembly without overlapping the filter when viewed from above.

A method for treating wastewater is disclosed. The method is useful in particular for treating wastewater that is generated from the process of drilling, hydraulic fracturing and/or cleaning a bore of an oil or natural gas well bore. The method may include performing cold lime softening of the wastewater to form waste salt floes, filtration of waste salt floes, ozonation of the filtrate from the filtration, and reverse osmosis of the filtrate to produce a purified permeate.

A water processing system includes an ultrafiltration membrane device (UF membrane device), a reverse osmosis membrane device (RO membrane device), an electric deionization device (EDI device), and an information processing device (edge computer). The information processing device controls operations of the ultrafiltration membrane device, the reverse osmosis membrane device, and the electric deionization device based on information on a water electrolysis device that obtains hydrogen by subjecting water to electrolysis. Water that is processed by the electric deionization device is supplied to the water electrolysis device. The water electrolysis device is able to obtain hydrogen by subjecting supplied water to electrolysis.