Hong Kong's compact water filter challenges reverse osmosis dominance

Since its introduction in the 1960s , reverse osmosis water filtration technology has been considered the most effective water filtration technology, occupying the high-end market. However, the problem of high operating costs is also quite prominent and has not been resolved. Mind Body, a Hong Kong company , has noticed this and cooperated with the Nano and Advanced Materials Research Institute ( NAMI ) to develop a very environmentally friendly and compact water filter based on new technical principles. Its filtration efficiency is the same as that of reverse osmosis filters. The water purifiers are similar, but the machine price and operating costs are much lower. There is a great opportunity to take a share of the high-end water filtration market.

Dr. Li Siyue, technical manager of Nano and Advanced Materials Research Institute Co., Ltd. (NAMI), and McConnell, director of Mind Body (Asia) Ltd., said that reverse osmosis (RO) water filtration technology had been successfully developed by the United States as early as the 1960s. With a history of more than 50 years, the market has generally recognized that reverse osmosis is the most effective water filtration technology. Even desalination plants in many countries use reverse osmosis water filtration technology. However, reverse osmosis water filtration technology also has some disadvantages, making its operating costs relatively high (including filter elements and electricity).

Operating cost machine price

Only half of a reverse osmosis water filter

Because the principle of reverse osmosis technology is to use high pressure to force water into a filter membrane with a pore diameter of less than 1 nanometer (nm) to achieve excellent filtration effects. The first disadvantage of this principle is that it requires a lot of electricity to generate high water pressure. The second disadvantage is that 50% to 60% of the water will bounce back and become "waste water" that needs to be drained away. For general commercial and household use, it is actually a huge waste of water.

In addition, due to the small diameter of the pores of the filter membrane, it is very easy to block. In addition, the filter membrane is easily destroyed by chlorine in tap water, so the life of the filter element is not very long. In order to extend the life of the reverse osmosis filter element as much as possible, the reverse osmosis water filter actually needs to use some traditional filter elements to absorb chlorine, heavy metals, etc. Generally, there are several filter elements in total. Other disadvantages include the slow water filtration speed, so a water storage tank is required, making it larger in size.

Winning prizes at the 47th International Exhibition of Inventions of Geneva

Therefore, in mid-2017, when Mind Body and NAMI were negotiating, they hit it off and decided to cooperate to develop a filtration efficiency similar to that of a reverse osmosis water filter, but superior in terms of operating cost, water filtration speed, volume, etc. "Zero waste water small water dispenser".

After a round of preparations, the cooperative research and development plan officially started at the end of 2017, with a total budget of more than 4 million yuan. Among them, Mind Body invested 51%, and the remaining 49% applied for funding from the "Innovation and Technology Fund". Recently, the research and development work of the "zero-waste water small drinking fountain" has been completed. At the "47th International Exhibition of Inventions of Geneva" held in April, the "Zero Wastewater Small Drinking Machine" also won the "Romanian Ministry of Scientific Research and Innovation Award".

NAMI: Switch to nanofiber filters

Li Siyue and McConning pointed out that compared with reverse osmosis water filters, "zero-waste water small drinking fountains" are very close in terms of filtration efficiency and do not lose any loss; but they are superior in other aspects, including: no need to use water when filtering water Electricity generates high water pressure (the water pressure of ordinary faucets is sufficient), does not produce waste water, has fast water filtration speed, and is small in size. It only requires two filter elements (one is porous ceramic and the other is nanofiber). The price of the machine and the cost of the filter element Lower and so on.

One of the main reasons is that the "Zero Wastewater Small Water Dispenser" abandons the single-layer filter membrane of the reverse osmosis water filter, which has a pore diameter of less than 1 nanometer, and instead uses the nanofiber filter membrane developed by NAMI. Li Siyue explained that the pore diameter of the nanofiber filter membrane developed by NAMI is about 100 nanometers to 200 nanometers (nm), but it uses a multi-layer structure and an arrangement of plum blossoms and bamboos to form the filter element. Therefore, although its filter hole diameter is larger, the actual filtration effect is comparable to the single-layer filter membrane of a reverse osmosis water filter, but it is not so easy to block.

No high water pressure required and no waste water produced

In addition, the surface of this nanofiber is also added with a bacteria-repellent function developed by NAMI, which can "bounce" 90% or more of the bacteria, so that they cannot attach to the surface of the nanofiber, lose ideal breeding conditions, and slowly Death in a drinking fountain. In contrast, the surface of the filter membrane of a general reverse osmosis water filter does not have a special antibacterial function (although 50% to 60% of the wastewater will rebound back).

As for the water filtration speed, the "Zero Wastewater Small Water Dispenser" is also far better than the larger reverse osmosis water filter. Taking an existing commercial reverse osmosis water filter from Mind Body as an example, its water filtration rate is only 0.5 liters per minute or more. Therefore, a water storage tank must be added to make its volume larger, reaching 0.045 cubic meters and weighing 10kg.

In comparison, the volume of the "zero-waste water small water dispenser" is 0.009 cubic meters, which is smaller than the former's filter element and weighs only 2kg. However, its water filtration speed reaches 2.5 liters per minute or more, which is about 5 times that of the former. times. If the reverse osmosis water filter wants to achieve the same water filtration speed, its volume will be much larger than the commercial model mentioned above by Mind Body.

Will Yunmei test obtain NSF certification

McConnell said that the "zero-waste water small water dispenser" is suitable for home use, small restaurants and offices with less than 60 people. Currently, 100 prototypes of the "zero-waste water small drinking fountain" have been produced. Dozens of them are being trialled by NAMI, and dozens more are ready to be shipped to the United States to be tested by the National Sanitation Foundation (NSF) to obtain certification from it.

Once it obtains NSF certification, it will produce "zero-waste water small drinking fountains" in Hong Kong and the Mainland, hoping to start within this year. As for the price, he refused to disclose the exact figure, but claimed that if compared with a reverse osmosis water filter with the same performance (including water filtration speed), it would be more than half cheaper, making it very attractive in terms of cost performance and competitiveness.

Source: Ming Pao