DESC:4. DESCRIPTION

Technical Field of the Invention

The present disclosure relates generally to the field of water purification. In particularly, it pertains to a compact RO (Reverse Osmosis) device that provides improved yield of ultra-pure water for Hemodialysis without the need to use an ion exchange softener module.

Background of the Invention

This invention relates generally to improvements in water purification systems of the type having a reverse osmosis (RO) unit or the like for removing dissolved ionic material and other contaminants from an ordinary supply of tap water or the like. More particularly, this invention relates to an improved water purification system having a reverse osmosis unit adapted for providing a supply of relatively purified water over a significantly extended operating life, and wherein water waste during normal system operation is substantially eliminated.

All dialysis centers are heavily dependent on a reliable and accountable supply of pure water. This water is used to prepare the dialysate used to purify blood in hemodialysis machines, and also for regeneration of the used hemodialyzer. Each hemodialysis session lasts for 3 hours and uses about 150 liters of water that has to meet stringent quality standards. The international standard for quality of hemodialysis water is set by ISO and Association for Advancement of Medical Instrumentation (AAMI) and is AAMI 13959-2014. Several MNC companies manufacture medical or dialysis grade RO plants, which assure dialysis quality water meeting AAMI 13959-2014.

India has about 40lakh end stage renal disease (ESRD) patients, whose kidneys have stopped functioning because of diabetes, hypertension or other reasons. Only 10-15% of these patients have access to kidney dialysis centres, and only about 0.125% can undergo kidney transplantation. The government of India recognises the gravity of the problem and is setting up hundreds of dialysis centres in PPP mode, through the National Dialysis Programme. Additionally, there are several chains of dialysis centres such as Nephroplus, Apex Kidney care, BRS Health and Research Institute, Eskag Sanjeevani, Deep Chand Dialysis Centre who collectively operate over a 1000 dialysis centres.

As these imported medical grade RO plants are very expensive, dialysis centers in small hospitals and dialysis chains in developing countries such as India use locally manufactured RO units that are normally used for drinking water production. The quality of water produced by these is a major concern, as kidney dialysis patients are already in a fragile state of health. Bad quality water can cause multiple health complications, including (i) anemia from aluminium, copper, zinc, chloramine, (ii) bone disease form aluminium, fluoride, (iii) hemolysis from copper, nitrates, chloramine, (iv) hypertension from calcium, sodium, (v) hypotension from bacteria, endotoxins, nitrates, (vi) metabolic acidosis from low pH, sulphates (vii) muscle weakness from calcium, magnesium (viii) neurological deterioration from aluminium, (ix) nausea and vomiting from bacteria, endotoxins, calcium, copper, low pH, magnesium, nitrates, sulphates, zinc etc.

However, all RO plants used for dialysis purposes, whether MNC products or locally manufactured ones, use a set of pre-filters to purify and prepare the raw water for the RO step. Invariably, these comprise a multi-media filter to remove sediments, an activated carbon filter to remove organic contaminants and an ion exchange resin softener module that reduces water hardness. The multimedia and activated carbon pre-filters have to be back-washed and rinsed to maintain, but the softener module has to be regenerated using 20-25kg of salt, and then rinsed. This requires 1-2 hours’ time every day and wastes water, electricity and also salt.

After the pre-filtration step, the raw water is sent to reverse osmosis membranes by high pressure pumps, where ions are rejected and removed in the reject stream. Permeate water, being purified, is used for the intended purpose. Also, RO systems may be single pass or double pass. Single pass systems have a single set of RO membranes, from where the product water is collected. Double pass systems take the permeate water from the first stage and feed it to a second set of RO membranes. The resulting water is thus double purified.

The reason a pre-filtration step is included is to avoid the RO membranes from getting damaged. Damage can happen from sediment fouling, biofouling or from scaling, which is caused by excessive hardness in the feed water. Thus there is a need to design and develop a compact RO system which provides ultra-pure water and prevents the wastage of salt and electricity as in the conventional RO systems used in hemo-dialysis.

Brief Summary of the Invention

According to an aspect of the present invention, a novel compact Reverse Osmosis (RO) system without a softener module for treatment of water used for hemodialysis is disclosed. More particularly the novel compact Reverse Osmosis (RO) system uses Hydrophilized Poly Amide RO membranes in a unique configuration instead of regular Poly Amide RO membranes, and is used specifically for kidney dialysis.

In accordance with the aspect of the present invention, the novel compact reverse osmosis (RO) system comprises of a control panel, a plurality of hydrophilized poly amide RO membranes (HPA) in combination with regular poly RO amide membranes installed in double pass configuration. The system also comprises of two pumps for pumping the water and passing them to the respective membranes in two stages. The system further comprises of a plurality of sensors and meters to track and monitor the TDS, pressure and flow rate from each membrane and current drawn by each pump. The system further comprises of a cloud server to monitor and maintain real-time processing information of the RO system.
In accordance with the aspect of the present invention, the RO system does not use a softener module, thereby saving about 20% water and electricity and also 20-25kg of salt every day. In addition to operational savings the RO system also prevents salt contamination of groundwater.

In accordance with the aspect of the present invention, the RO system employs a double pass system for achieving high purity water to meet AAMI 13959-2014 standards. The RO membranes are installed in a specific configuration to achieve protection from scaling, even in the presence of hard water.

In accordance with the aspect of the present invention, the RO system is equipped with 2 to 4 RO membranes in the first stage, each membrane ranging from capacities of 250 liters per hour (LPH) to 1000 LPH, and 2-3 RO membranes in the second stage, each membrane ranging from 250 LPH to 1000LPH in capacity.

In accordance with the aspect of the present the invention, wherein the first stage and/or the second stage RO membranes are a combination of regular poly amide RO membranes and hydrophilized polyamide RO membranes. Within each stage the first and last RO membrane is a hydrophilized polyamide membrane, with the remaining membranes being regular polyamide RO membranes.

In accordance with the aspect of the present the invention, wherein the RO system further comprises an array of sensors for TDS, pressure and flow rates at each stage to track and monitor any signs of fuming or scaling.

Major objects of the present invention are:
1. To achieve high quality product water meeting AAMI 13959-2014 standards while not employing a softener module.
2. To save water, electricity and salt by removing the softener step.
3. To accomplish double pass RO purification in a compact footprint.
4. To monitor the health of the RO plant by including TDS, flow and pressure sensors at critical locations, and then transmit the data to a cloud server so that the plant health data can be accessed from anywhere; and
5. Enable predictive maintenance by monitoring the plant data.

Brief Description of Drawings

The accompanying drawings illustrate the invention. In such drawings:

Fig. 1 illustrates the perspective view of the proposed RO system according to an exemplary embodiment of the present invention;

Fig. 2 illustrates the rear view of the system with the arranement of RO membranes arrangement according to the exemplary embodiment of the present invention;

Fig. 3 illustrtes the side view of the RO system according to the exemplary embodiment of the present invention;

Fig. 4 illustrates the bottom view of the system with first and second stge RO membranes for filtration according to the exemplary embodiment of the present invention.

Detailed description of the invention

According to an exemplary emodiment of the present invention, a novel compact reverse osmosis (RO) system (100) without a softener module for treatent of water used for hemodialysis is disclosed. The novel compact reverse osmosis (RO) system (100) comprises of a control panel for controlling and directing the flow of the water through the RO membranes. The RO system (100) also comprises a plurality of hydrophilized poly amide RO membranes (HPA) in combination with regular poly RO amide membranes (5) installed in double pass configuration, wherein the water treatment inside the said membranes (5,10) occur in at least two stages. The RO system (100) further comprises two pumps (6, 7) for pumping the water and passing them to the respective membranes in two stages. The RO system (100) further comprises sensors (2) for monitoring fluid paarmeters, and a cloud server for remote monitoring of the RO system.

Referring to the figures now;
Fig. 1 illustrates the perspective view of the RO system (100) according to an exemplary embodiment of the present invention. As shown in Fig. 1, the body of system is made up of stainless steel frames suitably welded and inside of which the RO membranes (5,10) are positioned in two stages that are used for purifying the permeate water with double pass configuration. Couple of pumps are also equipped to control the water flow and for pumping the water into the respective RO membranes (5, 10).

The conventional medical grade RO systems used for providing pure water for hemodialysis makes use of a resin softener module that reduces the hardness of feed water to safeguard the RO membranes such that scaling is prevented for the continuous generation of pure water. The challenge is that the softener has to be regenerated everyday with concentrated salt solution (25-40kg salt everyday). This salt is discarded after passing through the module. Following regeneration, the softener has to be rinsed with water to remove the salt from the system. This process causes wastage of salt, water and electricity for the process of regenerating and rinsing the softener. This problem is eliinated from the proposed RO device (100) by utilizing the novel hydrophilised polyamide membranes (5) which does not affect in scaling even from the hard water.

In accordance with the exemplary embodiment of the present invention, the hydrophilised polyamide membranes (5) are arranged in two stages in combination with the regular polyamide membranes wherein the first (5) and last membranes (10) are of hydrophilized poly amide RO membranes in arrangement with regular poly amide RO membranes positioned in the middle for the effective water treatment configuration. Placing the HPA RO membranes at the ends of the first stage of purification is for avoiding the scaling problem and result in the pure water in the first pass/stage of filtration and the purified water is then passed to the membranes (10) of the second stage with the aid of pump (7) and this passage of the purified water directly for the second stage of purification without storing it in a separate collection tank is termed as double pass configuration. This RO membrane configuration results in providing ultra-pure water twice as provided by the existing convetional RO systems which makes the proposed system more reliable and compact.

Fig. 2 illustrates the rear view of the system (100) with the arrangement of RO membranes arrangement according to the embodiment of the invention. As shown in FIG. 2 the positioning of the RO membranes (5,10) are seen from the rear side of the system (100). The purification of the feed water takes plce inside the RO membranes in two stages wherein the HPA membranes provide effective filtration due to its self regeneration and non-scaling properties. The double pass purification of the permeate water inside the membranes is controlled seamlessly with the aid of control panel. The output of the first pass RO is collected is directly pumped/fed to the second pass RO without the use of an intermediate tank making the apratus compact and inexpensive.

Fig. 3 illustrates the side view of system (100) and Figure 4 illustrates the bottom view of the system with first and second stage RO membranes for filtration according to the embodiment of the invention. As shown in FIG. 4, the system (100) is equipped with the HPA and regular RO membranes in double pass flow configuration in which the output of the first pass RO memranes (5) is directly fed to the second RO membranes (10) without the use of collection tank, making the system (100) and water treatment system robust and portable. The prification is done o two stages to provide an ultra pure water for hemo-dialysis.

The RO system (100) is enabled with Internet of Things (IoT) to access the information from a cloud server and to monitor the processing of the system remotely over wireless network.

S. No TEST PARAMETERS UNITS TEST METHODS TEST RESULTS Standards
As Per AAMI/
ISO:23500-2011
Physical Parameters
1 pH -- IS 3025 Part-11 4.89 6.50 - 8.50*
2 Color Hazen IS 3025 Part-4 Colorless < 5*
3 EC pinhos/em APHA 7.752 Not Specified*
Chemical Parameters
1 Turbidity NTU IS 3025 Part-10 <0.10 5.0*
2 Total Dissolved Solids mg/I IS 3025 Part-15 2 500*
3 Total Hardness as CaCO3 mg/I IS 3025 Part-21 Nil 200*
4 Calcium as Ca mg/I IS 3025 Part-40 Nil 2.0
5 Magnesium as Mg mg/I IS 3025 Part-46 Nil 4.0
6 Sulphates as SO4 mg/I IS 3025 Part-24 <0.10 100
7 Nitrates as NO3 mg/I IS 3025 Part-34 <0.10 2.0
8 Sodium as Na mg/1 IS 3025 Part-45 0.53 70.0
9 Potassium as K mg,/1 IS 3025 Part-45 <0.01 8.0
10 Fluoride ' as F mg/1 APHA-4500-1- 1) <0.10 0.20
11 Silica as Si02 mg/1 IS 3025 Part-35 <0.10 Not Specified*
12 Chloride as Cl mg/I IS 3025 Part-32 0.56 250*
13 Iron as Fe mg/I IS 3025 Part-53 <0.10 0.3*

Table 1: Physical and Chemical Parameters of Output RO water

S. No TEST PARAMETERS UNITS TEST METHODS TEST RESULTS Standards
As Per AAMI/
ISO:23500-2011
Trace Elements
1 Free Residual Chlorine -- mg/1 IS 3025 Part-26 <0.10 <0.5*
2 Copper as Cu mg/1 SM 3125 <0.01 <0.1
3 Barium as Ba mg/I SM 3125 ND(<0.001) <0.1
4 Zinc as Zn mg/1 SM 3125 <0.01 <0.1
5 Aluminium as Al mg/1 SM 3125 ND(<0.001) <0.01
6 Arsenic as As mg/1 SM 3125 ND(<0.001) <0.005
7 Lead as Pb mg/1 SM 3125 ND(<0.001) <0.005
8 Silver as Ag mg/1 SM 3125 ND(<0.001) <0.005
9 Cadmium as Cd mg/I SM 3125 ND(<0.001) <0.001
10 Chromium as Cr mg/1 SM 3125 ND(<0.001) <0.014
11 Selenium as Se mg/I SM 3125 ND(<0.001) <0.09
12 Mercury as Hg mg/1 SM 3125 ND <0.001) <0.0002
13 Chloramines (Combined) -- mg/I SM 4500-C1-G ND(<0.001) <0.1
14 Beryllium -- mg/I SM 3125 ND(<0.001) <0.0004
15 Thallium -- mg/I SM 3125 ND(<0.001) <0.002
16 Tin as Sn mg/I SM 3125 ND(<0.001) <0.1
17 Total Chlorine -- mg/I SM 4500-C1-G ND(<0.001) <0.5

Table 2: Trace Elements in Output RO water

S. No TEST PARAMETERS UNITS TEST METHODS TEST RESULTS Standards
As Per AAMI/
ISO:23500-2011
Microbiological Parameters
1 Total Bacterial Count Cfu/ml IS:5402-1969 Nil <50
2 Coli form MPN/ 100m1 IS: 5401-1969 Nil Nil*
3 E Coll - IS: 5887(part-I) 1976 Absent Absent/100ml*
4 Endo toxin EU/ml AAMI Standard method <0.001 0.25EU/ml (action limit >0.125 EU/ml)

Table 3: Microbiological Parameters of Output RO water
,CLAIMS:5. CLAIMS
I/We Claim
1. A novel compact Reverse Osmosis (RO) system (100) without a softener module for treatment of water used for hemodialysis, wherein the system (100) comprises of:
a control panel for controlling and directing the flow of the water through the RO membranes;
a plurality of hydrophilized poly amide RO membranes (HPA) in combination with regular poly RO amide membranes (5) installed in double pass configuration, the water treatment inside the said membranes (5,10) occur in at least two stages;
a couple of pumps (6,7) for pumping the water and passing them to the respective membranes in two stages;
a plurality of sensors (2) and meters (1) installed at multiple juntions of the system (100) to track and monitor the TDS, pressure and flow rate from each membranes and current drawn by each pump (6,7); and
a cloud server to monitor and maintain real-time processing information of the RO system (100);
Characterized in that
double pass flow configuration in which the output of the first pass RO memranes (5) is directly fed to the second RO membranes (10) without the use of collection tank, making the system (100) and water treatment system robust and compact;
at least 2 to 4 RO membranes of hydrophilized poly amide RO membranes (5) in combination with regular poly RO amide membranes are equipped for the first stage of purification and at least 2 to 3 RO membranes (10) are used for the second stage of treatment in which seamless water passage and treatment is achieved.

2. The RO system (100) as claimed in claim 1, wherein the first (5) and last membranes (10) are of hydrophilized poly amide RO membranes in arrangement with regular poly amide RO membranes positioned in the middle for the effective water treatment configuration.

3. The RO system (100) as claimed in claim 1, wherein the control panel is responsible for the seamless functioning of the double pass configuration in which the permeate water from the RO membranes (5) in first stage is directly fed into the RO membranes (10) of second stage and also enables to monitor the operation of the plurality of sensors equipped within the system for monitioring various fluid parameters.

4. The RO system (100) as claimed in claim 1, wherein the sensors (2) record the parameters such as but not limited to total dissolved solids (TDS), pressure inside the membranes (5,10) and water flow rate.

5. The RO system (100) as claimed in claim 1, wherein the requirement of of a softener module is eliminated from the system with the inclusion of hydrophilized poly amide RO membranes (5) and their installation in double pass configuration prevents the scaling even from the hard water and provide ultra-pure water for hemodialysis.

6. The RO system (100) as claimed in claim 1, wherein the standard capacities of each reverse osmosis (RO) membrane (5, 10) ranges from capacities of 250 liters per hour (LPH) to 1000 LPH and compact in size.

7. The RO system (100) as claimed in claim 1, wherein the sensor data (2) is stored and backed up into the cloud server at selected periods of time for research and development and performance monitoring purposes.

6. DATE AND SIGNATURE

Dated this 29th day of November 2020

Signature

(Mr. Srinivas Maddipati)
IN/PA – 3124
Agent for Applicant