1. Background
Drinking water safety is directly linked to the physical health of the general public. Ensuring drinking water safety is a fundamental requirement for thoroughly implementing the Scientific Outlook on Development and safeguarding the fundamental interests of the vast majority of the people. In recent years, in accordance with the directives of the Party Central Committee and the State Council, various regions and relevant departments have prioritized urban and rural drinking water safety, further intensifying their efforts and increasing investment. They have implemented a series of engineering and management measures to address drinking water safety issues for some urban and rural residents. However, with the progress of the times, the public’s expectations regarding drinking water are no longer limited to merely “having water to drink” and basic safety; instead, they have higher expectations for “drinking good water.” This necessitates that the water supply system continue to improve and refine its ability to provide high-quality, convenient, and safe drinking water.
Currently, the “Sanitary Standards for Drinking Water” (GB5749-2022) implemented by China’s tap water industry covers a relatively limited number of testing parameters. Furthermore, traditional water treatment processes have inherent limitations, making it difficult to meet the standards for direct drinking water. Additionally, the tap water distribution network faces serious issues of secondary contamination, such as corrosion and leaks in pipes due to long-term use, which allow impurities to enter the water; as well as scale buildup, sedimentation, and the proliferation of bacteria and other contaminants inside the pipes. Meanwhile, although purified and distilled water remove harmful components during production, they also inevitably strip away beneficial trace elements, and long-term consumption may have adverse health effects. Bottled water, on the other hand, faces numerous issues such as contamination from water dispensers, insects entering the spout, and air pollution, making it difficult to meet people’s demand for convenient, safe, and high-quality drinking water.
Against this backdrop, piped drinking water has emerged as a key solution to drinking water safety issues. Piped drinking water is short for “high-quality piped drinking water.” It employs a differentiated water supply system, establishing water purification stations within residential communities (hotels, office buildings). Using modern high-tech biochemical and physical-chemical technologies, it performs advanced purification of tap water to remove harmful substances such as organic matter, bacteria, and viruses, while retaining beneficial trace elements and minerals; Simultaneously, high-quality piping is used to establish an independent recirculating pipeline network that delivers the purified water directly to users’ homes (or guest rooms and offices) for immediate consumption.
2. Common Pipe-Delivered Drinking Water Treatment Solutions
Solution 1: Activated Carbon Adsorption + Ultrafiltration Process
Activated carbon adsorption utilizes the material’s vast specific surface area and porous structure to adsorb organic compounds, residual chlorine, odors, and certain heavy metals from the water. Ultrafiltration is a pressure-driven membrane separation technology that uses the sieving action of ultrafiltration membranes to retain bacteria, viruses, colloids, and large organic molecules, ensuring the treated water meets direct drinking water quality standards.
Solution 2: Activated Carbon Adsorption + Nanofiltration Process
After activated carbon adsorption pretreatment, the water passes through a nanofiltration membrane. Nanofiltration is a pressure-driven membrane separation technology that falls between reverse osmosis and ultrafiltration. Its membrane pore size is smaller than that of ultrafiltration membranes, enabling it to retain certain low-valent ions and small-molecule organic compounds while removing most heavy metal ions, viruses, bacteria, and other contaminants.
Solution 3: Activated Carbon Adsorption + RO Reverse Osmosis Membrane Process
Activated carbon adsorption is used to pretreat the raw water, removing large-molecule organic compounds, residual chlorine, and other substances that could damage the reverse osmosis membranes. The pretreated water then enters the reverse osmosis system, where, under high pressure, it passes through the reverse osmosis membranes. This process retains nearly all dissolved salts (including heavy metals and minerals), colloids, bacteria, viruses, and other harmful substances, thereby producing high-quality drinking water.
Although the initial investment and operating costs of the RO reverse osmosis membrane treatment process are relatively high, from a long-term operational perspective, the benefits derived from its stability and high-quality output water can offset the increased costs. High-quality drinking water improves residents’ quality of life, reduces the risk of diseases caused by consuming contaminated water, and helps enhance the market competitiveness of the drinking water system. Furthermore, with continuous technological advancements, the cost of reverse osmosis membranes and operational energy consumption are gradually decreasing, alleviating cost pressures to a certain extent.
In summary, the RO reverse osmosis membrane treatment process, with its exceptional water treatment performance, broad adaptability, and long-term benefits, has become the optimal choice for piped drinking water systems.
3. Reverse Osmosis (RO) Process System and Water Supply Model
I. Pretreatment
1. Water Source Selection: The raw water for drinking water must be tap water that meets the quality standards for domestic drinking water sources.
2. Preliminary Filtration: This step removes larger solid suspended solids from the raw water, such as silt, rust, and other impurities visible to the naked eye. This can be achieved using mechanical filters or quartz sand filters, which utilize the physical interception properties of filtration media (such as quartz sand or anthracite) to remove large particles from the water, reduce turbidity, and prevent these impurities from causing wear or clogging in subsequent treatment equipment.
3. Activated Carbon Filtration: Activated carbon adsorbs odors, discoloration, certain organic and inorganic impurities, and removes residual chlorine from the water. Residual chlorine can damage downstream treatment components such as reverse osmosis membranes, so its removal is critical.
4. Water Softening: If the source water has high hardness—that is, if it contains a high concentration of calcium, magnesium, and other ions—softening treatment is required. Typically, softening agents such as ion exchange resins are used to replace calcium and magnesium ions in the water with sodium ions, thereby reducing water hardness and preventing scale formation during subsequent treatment processes that could affect the normal operation of equipment.
5. Fine Filtration: Spiral-wound or melt-blown polypropylene fiber filter cartridges are used, with pore sizes of 5, 3, 1, and 0.22 μm available, to remove trace suspended solids or fine particulate impurities.
II. Membrane Separation
1. Reverse Osmosis (RO) Treatment: This is the core process of drinking water treatment. Reverse osmosis membranes possess extremely high filtration precision, effectively removing nearly all impurities from the water—including dissolved salts, heavy metals, organic compounds, bacteria, and viruses—to achieve a very high level of water purity. Under pressure, water passes through the reverse osmosis membrane while impurities are retained and flushed out, thereby purifying the water. After reverse osmosis treatment, indicators such as electrical conductivity and total dissolved solids are significantly reduced, meeting the standards for direct drinking water.
III. Sterilization and Disinfection
1. UV Disinfection: Ultraviolet (UV) light has a bactericidal effect, capable of destroying the nucleic acid structures of microorganisms such as bacteria and viruses, rendering them inactive. UV disinfection equipment is installed in water supply pipelines or storage tanks; as water passes through the UV irradiation zone, microorganisms are inactivated, thereby ensuring the microbiological safety of the water.
2. Ozone Disinfection: Ozone possesses strong oxidizing properties, capable of rapidly killing microorganisms such as bacteria and viruses in water. It also oxidizes and decomposes organic matter in the water, improving its taste and odor. Ozone disinfection can be performed as pre-ozone oxidation during the water treatment process or as post-ozone sterilization during water storage or distribution.
IV. Point-of-Use Treatment and Water Dispensation
Variable-frequency water supply systems or other water supply equipment are used to maintain stable water pressure, ensuring that treated drinking water is delivered smoothly to all points of use. The treated drinking water is ultimately supplied to users through the dispensing outlets.
V. Digital Solutions
Smart water meters are deployed, and sensors are installed on drinking water equipment, supply pipelines, and terminal devices to monitor equipment operation status, water quality parameters, water pressure, and flow rates in real time. These devices are interconnected via an IoT platform to enable communication and data transmission between them.
Big data analytics tools are used to analyze and mine the vast amounts of collected data to understand user water consumption habits, equipment operational trends, and patterns of water quality changes. Big data analysis enables the optimization of water supply scheduling, the prediction of equipment failures, the formulation of maintenance plans, and the provision of high-quality, personalized services to users.
Mobile applications and WeChat official accounts will be developed to allow users to check water quality information, water consumption, and payment status anytime, anywhere. Additionally, users can use the mobile platform to manage water cards, top up balances, and report repairs online, thereby enhancing service convenience and user satisfaction.
Our company specializes in the R&D and manufacturing of reverse osmosis (RO) systems, pure water systems, EDI ultrapure water systems, ultrafiltration (UF) systems, wastewater treatment systems, water softening systems, well water filtration systems, RO membranes, and water purification and wastewater treatment materials. With years of experience in the water treatment industry, we provide robust technical support for water treatment challenges across a wide range of scenarios. We welcome discussions regarding potential collaborations.
