A water purification apparatus (1) comprising a Reverse Osmosis, RO, device (26). The RO device (26) comprises a RO membrane (26a) and a feed pump (23). The apparatus (1) also comprises a recirculation mechanism (33) arranged to recirculate a portion of the reject water to the feed water, a temperature sensor device arranged to measure a temperature indicative of the temperature of the RO membrane (26a), and a flow rate sensor device arranged to measure a flow rate indicative of the permeate flow rate of the permeate water. The apparatus (1) further comprises a control arrangement (50) configured to control recirculation to achieve a predetermined recovery ratio. The control arrangement (50) is also configured to control the rate of the feed pump (23), based on the measured temperature indicative of the temperature of the RO membrane (26a) and a desired permeate conductivity, to make the permeate flow rate equal to, or within a predetermined margin of, an energy efficient permeate flow rate determined based on a predetermined relation between RO membrane temperature, permeate flow rate and permeate conductivity. The disclosure also related to a corresponding method.

The present invention relates to a fresh water generation method using a water treatment apparatus, the method including feeding water to be treated into a membrane element including a reverse osmosis membrane or a nanofiltration membrane to separate into concentrate and permeate, in which the method includes, under operation of the apparatus, adjusting a concentrate flow rate and/or a permeate flow rate based on a water quality index of the water to be treated and a water quality index of combined water prepared by combining the concentrate and the permeate at a ratio based on a predetermined permeate recovery rate, so that the water quality index of the water to be treated falls within a tolerance on the water quality index of the combined water.

A MEMS sensor system for monitoring membrane elements in a membrane based water filtration plant having a remote telemetry unit (RTU), a SCADA, and a plurality of MEMS sensors for measuring pressure, flow rate. and conductivity. The water filtration plant has a train with a membrane vessel containing a plurality of membrane elements arranged in series creating interfaces between each membrane element. The MEMS sensors are located at the membrane element interfaces. A method of monitoring membrane elements in a membrane based water filtration plant using a plurality of MEMS sensors for measuring pressure, flow rate. and conductivity placed at the filtration plant membrane element interfaces.

A reverse osmosis water purifier that monitors Total Dissolved Solids (TDS) at the onset of entering the water filtration system and downstream upon exiting the system. A comparison of the TDS levels is made to each other or predetermined levels, and action is taken regarding whether to bypass the RO filter, or continue filtering through the RO membrane, or combine the two fluid streams. A microbiological barrier filter is introduced in-line with the egress port of a reverse osmosis filter, and downstream of the bypass water circuit. The microbiological filter is utilized to remove microbiological contaminants from the output water, either directly from the RO filter output, or the bypass filter circuit, or both.

The method of verifying an RO membrane of an RO installation is characterised in that the conductivity values of the supplied raw water and of the permeate and the amount of the raw water inflow and the concentrate outflow are continuously or cyclically measured and that the efficiency of the RO membrane, its retention rate and/or filtration efficiency are calculated from the measured values.

An aim of the disclosure is to control a water purification apparatus that uses reverse osmosis (RO) to consistently produce permeate water with a desired quality. The permeability of a RO membrane varies with a temperature of feed water. Hot water has a lower viscosity and a higher diffusion rate than cold water. The pores of the RO membrane expand at higher temperatures, causing a higher flow through the RO membrane from a feed to a product side. Consequently, higher temperatures cause higher permeate flow over the RO membrane and increased salt passage through the RO membrane. In order to improve the salt rejection rate, more permeate water needs to pass through the RO membrane to dilute the salts. This is achieved by increasing feed side pressure when the RO membrane temperature increases, thereby causing an increased flow of permeate water.

A reverse osmosis system includes a first conductivity sensor for measuring electrical conductivity of water supplied to the reverse osmosis system, and a second conductivity sensor for measuring electrical conductivity of a permeate produced by the reverse osmosis system. The system also includes an AI unit designed to use a statistical model for calculating and accordingly setting a proportion of a concentrate produced by the reverse osmosis system that is to be recirculated according to the measured electrical conductivity of the water supplied to the reverse osmosis system, and according to the measured electrical conductivity of the permeate produced by the reverse osmosis system. The statistical model can be trained with training data.

A control system configured to control operation of reverse osmosis (RO) array(s), nanofiltration (NF) array(s) and/or a blending system including a control panel (CP), regulatory controllers (RCs), and a supervisory controller (SC), wherein the SC is in signal communication with the CP, and with the RCs, wherein the SC is configured to: receive user inputs from the CP, and receive inputs from RCs regarding data from sensors, wherein the RCs are in signal communication with the plurality of sensors, wherein the RCs are configured to: receive data from the sensors, provide outputs to and receive permissions from the SC, and instruct devices in response to the received permissions from the SC, and wherein the SC is configured to: monitor trends in the inputs regarding and/or predict outcomes from data received from the RCs and determine the permissions for RCs based on the monitored trends and/or user inputs from the CP.

A cleaning-in-place method for cleaning a membrane filter module, the membrane filter module including a membrane having a feed side and a permeate side and being configured to filter a fluid passing through the membrane from the feed side to the permeate side; wherein the method comprises performing a sequence of process cycles, the sequence comprising at least one monitored process cycle, the monitored process cycle comprising: providing a flow of a liquid through the membrane and/or across the feed side of the membrane; monitoring at least one hydraulic parameter associated with the provided flow of the liquid; and terminating the flow of the liquid, when the at least one monitored hydraulic parameter meets a predetermined cycle completion criterion.

The disclosure relates to systems, devices, and methods for flow control in a reverse osmosis filtration system, such as within a medical device. The systems, devices, and methods can respond to changes in permeate flow rate and solute concentration by adjusting feed water and concentrate water rates. Multiple feedback loops adjust parameters to meet water flow rate and purity requirements.