Abstract : The key areas of research and development in water industry equipment include wastewater treatment machinery, sand removal and sludge scraping equipment, aeration and mixing equipment, chemical dosing and disinfection equipment, concentration and dewatering equipment, and oxidative desalination equipment. In recent years, membrane treatment equipment, biogas utilization equipment, sequencing batch decanting equipment, sludge post-treatment equipment, and solid waste treatment equipment have also been added. China's environmental governance and water industry are experiencing rapid development and opportunities. Driven by the demand for high-efficiency equipment and constrained by funding, developing high-level domestic water industry equipment based on existing production has become an urgent task. How to utilize this opportunity to elevate the level of China's water industry equipment to a new height will be a new opportunity and a new challenge for water supply and drainage researchers, water industry equipment workers, and manufacturers. Keywords : Water industry machinery and equipment, overall situation, development. I. Introduction After nearly 50 years of development, China's water industry equipment discipline has gradually become more complete. Water industry machinery and equipment can be broadly categorized into general-purpose machinery and equipment and special-purpose machinery and equipment. General-purpose machinery and equipment mainly includes pumps, valves, and fans. Special-purpose machinery and equipment represents the focus of research and development in the water industry and includes equipment for controlling wastewater discharge, sand removal and sludge scraping, aeration and mixing, chemical dosing and disinfection, concentration and dewatering, and oxidative desalination. In recent years, membrane treatment equipment, biogas utilization equipment, sequencing batch decanting equipment, sludge post-treatment equipment, and solid waste treatment equipment have also been added. Over the past two decades, through loan and borrowing projects, many water plants and wastewater treatment plants have developed novel, lightweight, energy-efficient, and low-consumption advanced equipment from various countries. This has led manufacturers and researchers in the water industry to recognize that, in addition to their comprehensive mechanical functions and reliable operation, these devices can fully meet the requirements of new process development, satisfy high-level process standards, and overcome limitations imposed by existing processes. These devices not only represent a qualitative change in their operating mechanisms and mechanical structures compared to similar equipment but also, to a certain extent, provide possibilities and guarantees for process innovation and transformation. At the turn of the century, my country's environmental governance and water industry experienced rapid development and presented numerous opportunities. Driven by the demand for high-efficiency equipment and constrained by funding, developing high-level domestic water industry equipment became an urgent priority, building upon existing production. How to leverage this opportunity to elevate my country's water industry equipment to a new level presents both new opportunities and challenges for water supply and drainage researchers, water industry equipment workers, and manufacturers. However, it is crucial to recognize that the gap between our current water industry equipment and that of foreign countries is greater than the gap in water technology; the gap in theoretical research and manufacturing of specialized water industry equipment is even greater than the gap in general-purpose equipment. This presents a significant challenge for my country's water industry workers. Therefore, improving the industrialization level of my country's water industry hinges on developing water industry equipment, especially high-level specialized water industry machinery and equipment—this is the most pressing task for my country's water industry equipment sector. II. Development Patterns and Characteristics of Water Industry Machinery and Equipment Abroad (I) Development Patterns and Current Status of Water Industry Equipment Abroad Before the late 1960s, the focus of water supply and drainage engineering construction in various countries was on urban water supply. Therefore, the development of water supply and drainage machinery and equipment was mainly focused on large-scale urban water supply projects and decentralized small-scale industrial wastewater treatment. Water supply and drainage machinery and equipment were mainly general-purpose equipment. Due to the relatively low requirements for water quality, the instruments and meters were also relatively simple. In the early 1970s, in order to adapt to the development of industrialization and the improvement of people's living standards, the water supply coverage rate in industrialized countries had successively reached 85-95%, and the per capita domestic water consumption exceeded 200-300 liters/person/day. The rapid development of industrialization and the daily increase in water consumption have also brought about serious water pollution problems, which directly threaten people's lives and health and human development and survival. Given that environmental pollution has become a global strategic development issue, it has attracted widespread attention from governments and people of all countries. Many countries, especially industrialized nations, have implemented a series of significant environmental protection measures, such as establishing environmental management agencies, developing national and even global environmental protection strategies, and enacting laws and regulations. These measures compel governments and private enterprises to allocate funds to address the increasingly severe environmental pollution problems. The focus of water supply and drainage engineering construction has gradually shifted towards centralized urban sewage treatment, with increasingly larger scales and higher technical requirements. Consequently, the environmental protection industry has emerged, and water treatment machinery and instruments, as a major category of environmental protection equipment, have developed rapidly, forming a self-contained and specialized production system. In the early 1970s, water purification processes were primarily mechanized, resulting in lower technical requirements for water supply and drainage machinery and equipment, with manual operation and management being the main methods. However, with increased knowledge and a deeper understanding of the impact of water quality on human health and industrial production, coupled with the energy crisis and the need to reduce energy consumption and save on operating and management costs, it has become impossible to achieve a balance between high-quality effluent and low-cost treatment. The application of computer technology to industrial production has also led to the integration of automation technology into water treatment processes in developed countries. Automation is predicated on the automation of machinery and instruments, thus further driving the technological development of water supply and drainage machinery, equipment, and instruments. In the early 1980s, the environmental protection industry experienced rapid growth, expanding significantly in scale and with an annual output value increase rate much faster than other machinery manufacturing industries. For example, the United States has over 600 companies and approximately 700,000 employees engaged in environmental protection, with an average annual output value increase of 20%, more than double that of other machinery manufacturing industries; Japan has 700-1000 companies and nearly 30,000 employees; West Germany has over 800 companies; and Sweden, with a population of only 8 million, has over 100 environmental protection companies. Enterprises engaged in the production of water supply and drainage machinery and equipment in industrialized countries can be divided into the following types: 1. Large international multinational corporations: such as Barwat Water Treatment Group in the UK, Doyle-Oliver in the US, De Grémont in France, ETT Fibre in Sweden, DHV in the Netherlands, Ebara in Japan, etc. They have a long history, strong strength, and numerous patents. They can both contract for design and manufacturing and provide complete sets of water supply and drainage treatment equipment. 2. Water treatment equipment manufacturing subsidiaries or divisions of large international monopolies. Such as Kluge, Posadwan, and Mannersmann in West Germany; Amico, Westinghouse Electric, and Dow Chemical in the US; Ishikawajima-Harima, Mitsubishi Heavy Industries, Tsukishima, Hitachi, Kubota, etc. in Japan. They can supply environmental protection equipment as an add-on to complete sets of petroleum, chemical, mining, metallurgical, and shipbuilding equipment, or supply complete sets of equipment separately. However, these companies mainly supply complete sets of sewage treatment equipment. 3. A large number of small and medium-sized enterprises. Among them are companies like Simon Hartley (UK), Ritz (West Germany), EMU (West Germany), KSB (West Germany), Amber (West Germany), Kurita (Japan), Suido Kikyo (Japan), and Norpong (Finland). These companies primarily produce single, brand-name products, but can also provide complete sets of equipment through collaboration with other companies. These companies are highly specialized, technologically advanced, and business-flexible, making them competitive enterprises. Foreign manufacturers of water treatment machinery and equipment generally possess considerable technical capabilities in research, design, development, installation, and monitoring. They emphasize product upgrades, continuously improving and updating equipment performance and frequently introducing new models. The production of water treatment instruments and meters is still largely handled by established industrial instrument manufacturers, such as Yokogawa-Hokushin (Japan), Kent (UK), and Siemens (West Germany). Looking at the development of water treatment machinery, equipment, and instruments in developed countries, as people's awareness of environmental protection increases and the requirements for water quality become more stringent, water treatment processes are trending towards larger scale and greater complexity. However, in terms of the water treatment machinery itself, the trend is towards high efficiency, energy saving, lightweight yet high strength, good durability, flexible and reliable operation, and mechatronics integration. High technologies (such as programmable control, rigid feedback regulation, and microcomputer management) are also being incorporated into the manufacturing and operation of water treatment machinery. Water treatment instruments not only include various traditional components for detection, conversion, display, regulation, and execution, but also enable water industry machinery and instrumentation control to achieve programmable control, interlocking protection, automatic flushing, information transmission, telemetry and remote control, data processing, computer control, and self-diagnostic fault diagnosis, as well as durability and adaptability to automated control requirements. Because the penetration rates of tap water and wastewater treatment in developed industrial countries are nearing saturation, and their domestic markets are shrinking, some water treatment machinery and instrument manufacturers are gradually shifting their focus to developing countries. (II) Development Characteristics of Foreign Water Supply and Drainage Machinery and Instruments From the development process of water supply and drainage machinery and instruments in industrialized countries around the world, it is clear that the development of the water treatment machinery and instrument industry is closely related to the economic development and environmental protection policies of various countries. Its technological level is influenced by the level of basic industries and a strong sense of market competition. Below, we will attempt to analyze the development characteristics and influencing factors of foreign water supply and drainage machinery and instruments from the perspectives of policy, management system, investment, and the level of basic industries. 1. The development of water treatment machinery is closely related to the economic development situation of various countries. In the 1960s, the rapid economic development of industrialized countries, coupled with the neglect of environmental protection, led to serious environmental pollution problems and huge economic losses. According to estimates by the Organization for Economic Cooperation and Development (OECD) of West Germany, the economic losses caused by environmental pollution accounted for approximately 3-5% of GDP. In the 1970s, the Great Depression slowed the rapid economic development, but lessons were learned, and the importance of environmental protection was gradually strengthened. It was recognized that investment in environmental protection industries was also a low-input, high-output means of economic development. For example, the period from 1969 to 1974 was a period of rapid economic growth for Japan, coinciding with a period of strengthened environmental legislation. During this time, the environmental protection industry experienced phenomenal growth, with over a thousand manufacturing companies. However, after the global oil crisis erupted at the end of 1973, the Japanese economy entered a period of slow to moderate growth, and the focus of environmental policy shifted from industrial waste treatment to the improvement of the living environment. Conversely, orders for environmental protection equipment for treating urban sewage, excrement, and garbage to improve the living environment rose rapidly. Consequently, a significant number of manufacturers shifted their production focus, as exemplified by the rapid development of Hitachi Zosen Corporation's environmental equipment business. 2. Establishing a unified management organization and adopting strong promotion and supervision measures are reliable guarantees for the development of the water treatment machinery manufacturing industry. Initially, Japan experienced a series of problems in the production of environmental protection equipment, such as poor product performance and shoddy workmanship, which seriously affected the functionality of environmental protection facilities. To address this, they successively established the "Industrial Pollution Management Committee" and the "Committee for the Implementation of Emission Standards for Pollution Prevention Devices," actively carrying out various activities. To support the development of new products, unified quality and inspection standards were established, feasibility studies were conducted beforehand, and interest-free loans were provided. Specialized inspection and acceptance agencies were set up within the Ministry of International Trade and Industry (MITI), and a system for recognizing high-quality equipment and devices was established. Therefore, in the 1970s, various advanced technologies and devices that were urgently needed and immediately effective were continuously developed in various fields. While actively constructing various facilities, process flows and equipment were also modified to prevent secondary pollution. In 1970, the United States established the Environmental Protection Agency (EPA) as a policy agency specifically responsible for environmental affairs. In 1974, in response to numerous problems exposed during the use of machinery and instruments used for the automated operation and management of wastewater treatment plants, affecting the implementation of automated systems in wastewater treatment plants, the EPA organized an expert meeting at Clemson University to specifically discuss the problems that needed to be studied and solved in the automation of wastewater treatment systems. At the meeting, experts unanimously agreed that "the reliability of equipment and the inadequacy of sensor instruments are the key issues." In 1975, the EPA established a temporary committee to further investigate the problems existing in instrumentation in the field of automation. Based on this work, and after investigation and research by all parties, in order to better coordinate potential legal, economic, and technical issues between users and manufacturers, the U.S. Environmental Protection Agency and the National Bureau of Standards jointly established an office to formulate performance, technical specifications, and test methods for several online instruments and meters used in wastewater treatment, and to issue quality certification certificates. This played a positive role in guiding and promoting the development of water treatment machinery, equipment, and instruments. 3. Prioritizing environmental investment is an economic lever for promoting the development of water industry equipment. From the economic benefits of developing industry, the economy, and environmental protection, it is clear that investment in environmental protection is far less than the economic losses caused by environmental pollution, and in a sense, it can be considered to have the advantage of appropriately compensating for economic losses. Therefore, many industrialized countries attach great importance to investment in environmental construction and adopt some preferential investment policies. Investment in water supply and drainage engineering facilities accounts for a large proportion of urban infrastructure investment and environmental protection construction investment. For example, in 1978 and 1979, France's policies allocated 35.8% and 35.7% of its total environmental protection infrastructure investment for water pollution prevention and control, respectively. The investment far exceeds the costs of other pollution control measures, such as air pollution, noise pollution, waste residue, and toxic substances. Western European experts believe that the funds invested in preventing environmental pollution are 50% less than the losses caused by neglecting to protect nature. Between 1976 and 1980, national investment in pollution prevention equipment and measures was double that of the previous five years, resulting in a 15% reduction in air pollution and a 28% reduction in wastewater. Investment policies prioritizing environmental construction and urban infrastructure, as an economic lever, powerfully promoted the development of water industry equipment. West Germany invested 120 billion marks in environmental protection from 1971, accounting for 1.1% of its GDP, with over 800 environmental equipment manufacturing companies generating 21 billion marks in revenue, representing 17.5% of the investment. 4. The formulation and improvement of water quality regulations and standards effectively controlled water pollution, forcing water treatment equipment and instruments to develop in greater variety, diversity, and depth, promoting product standardization, serialization, and matching. In the early 1970s, apart from some water supply and drainage regulations governing interstate transportation, the United States lacked a unified and enforceable national water quality standard. Although each state had its own standards, there were significant differences between states in terms of scope and stringency. This made water pollution control difficult to implement. Therefore, in 1972, the U.S. Environmental Protection Agency (EPA) drafted the Clean Water Act (CWA). In the ten years following its passage, the U.S. spent nearly $42 billion on policy to achieve these goals. The EPA, in accordance with the Safe Drinking Water Act, issued the National Provisional Water Standards, which set forth 30 primary indicators (hazardous substances) and 13 secondary indicators (apparent indicators). In 1986, the Safe Drinking Water Act was further revised, increasing the number of primary water quality indicators from 30 to 83 and imposing mandatory deadlines for the management of critical pollutants. The formulation and improvement of these water quality regulations and standards broadened the development goals of water treatment machinery and instruments, forcing water supply, environmental protection, and manufacturing companies to strive to develop new technologies, processes, and equipment to meet the requirements of the two laws. This promoted the development of a diversified, multi-variety, and product-oriented main structure in the industry, and also led to a surge in the production and sales of water treatment equipment. The situation was similar in Europe. The European Community independently developed a series of standards, which were published as directives in 1980. According to the treaty establishing the European Community, all member states—Belgium, Denmark, France, West Germany, Greece, Ireland, Italy, Luxembourg, the Netherlands, Portugal, Spain, and the United Kingdom—were required to take measures to ensure the quality of drinking water, meeting the standards stipulated in the directives within five years, by July 1985. These standards covered sensory indicators (42 items), physicochemical indicators (10 items), indicators of substances that should not be consumed in excessive amounts by the human body (18 items), and toxicity indicators (11 items). The determination of these detailed indicators spurred the in-depth development of water treatment machinery and instrumentation technology. The formulation and improvement of water quality standards have raised the requirements for effluent quality and increased the complexity and reliability of treatment processes. Traditional experience-based operation and management are no longer adequate to address the complexity of these processes. Automatic monitoring and program control are now essential to address the dynamic nature of water treatment processes, highlighting the necessity of automation. Introducing automation and microcomputer-controlled operation and management to address the complexity of water treatment processes involves improving the level of mechanization and instrumentation. Instruments are like the operator's eyes, machinery is like the operator's hands and feet, and the microcomputer is like the human brain. Overcoming these technical challenges is a systematic project. In the mid-1970s, developed countries invested heavily in this area and achieved breakthroughs. Mechanization, instrumentation, and ultimately automation have significantly improved the systematization, compatibility, and standardization of water treatment machinery, equipment, and instruments, leading to a leap forward in water treatment technology. Although automation in water treatment processes increases investment in engineering construction, it brings overall economic and social benefits. 5. The level of basic industries abroad forms the foundation and cornerstone of the development of water industry equipment. The level of basic industries is reflected in the manufacturing and processing of water supply and drainage machinery and instruments, primarily in the selection of materials and manufacturing processes; in product performance, primarily in product precision, reliability, durability, energy efficiency, and high efficiency; and in treatment processes, in accurate control and feedback regulation, making automation of water treatment processes possible. The combination of these aspects reflects the level of a country's basic industries. This can be illustrated by the selection of materials in the manufacture of water treatment machinery and equipment. Water treatment machinery operates under harsh environmental conditions, with strong corrosiveness and significant variations in temperature and humidity. Therefore, the choice of materials almost entirely determines the quality of the equipment. Developed industrial countries, due to their high industrial levels, generally use stainless steel and alloy steel as primary materials. Even when using ordinary carbon steel in non-rotating parts, strict sand removal and anti-corrosion measures are taken. The choice of materials greatly improves the durability and reliability of the products, ensuring their functionality. 6. A strong sense of market competition and an emphasis on the research, development, design, and manufacturing capabilities of enterprises are the driving forces for development. A prominent feature of foreign water treatment equipment manufacturers is that they integrate scientific research, development, design, manufacturing, and installation. They offer complete product supply, turnkey engineering projects, emphasize after-sales service, and prioritize corporate reputation. Their organizational structure is flexible, with rapid and efficient information feedback, adapting well to market competition. III. Current Status and Classification of Specialized Water Industry Machinery and Equipment in China (I) General Status of Water Industry Equipment Production 1. General Machinery and Equipment Although China's water treatment equipment production has reached a considerable scale, it still lags far behind international advanced levels and is not well-suited to the requirements of China's water treatment technology development. ① Water treatment blowers mainly include centrifugal blowers and Roots blowers. Significant progress has been made in the development and production of centrifugal blowers in China. New high-speed centrifugal blowers have been developed, employing advanced three-dimensional impellers, adjustable inlet and outlet guide vanes, and featuring high efficiency and energy saving, a wide adjustable flow range, compact structure, low noise, and high reliability. Future development should focus on high-efficiency and energy-saving water treatment blowers, improving the overall series, increasing automation levels, reducing noise, and lowering costs. Particular attention should be paid to blowers suitable for small and medium-sized wastewater treatment plants that can adapt to varying operating conditions, leveraging their low price and ease of maintenance. Roots blowers have a long history of application in the water industry. However, their usage declined in the past due to factors such as high noise levels, low pressure rise, and a lack of suitable specifications for water treatment. Since the late 1980s, my country has undertaken significant technological upgrades to its existing Roots blowers. In 1993, a joint design of a series of Roots blowers organized by the Ministry of Machinery Industry was successfully completed. These blowers feature advanced structures, high levels of standardization, and integration, essentially reaching the level of similar foreign products, particularly the successful development of three-lobe, low-noise Roots blowers. These technologies can meet the technical requirements for blowers used in the water industry. In the future, domestically produced Roots blowers still need to strive to narrow the gap with international advanced levels in areas such as noise reduction, efficiency improvement, casting process improvement, and parts machining precision. Valves for water treatment mainly include butterfly valves, gate valves, check valves, and valve actuators. Valves are one of the most widely used pieces of equipment in the water industry. Although not extremely complex, leaks and spills are common problems in domestically produced valves, a persistent challenge for the operation and management of water plants and wastewater treatment plants for many years. To improve the technical performance and quality of domestically produced valves, since the 1980s, leading enterprises have been organized to introduce advanced technologies and processing equipment from foreign counterparts, achieving significant progress. Currently, leading enterprises can design and manufacture various valves according to ISO international standards, DIN German standards, and AWWA American standards, with some manufacturers' products reaching international advanced levels. Although the overall level of the domestic valve industry has improved significantly, there is still a general gap in appearance quality. Further technological upgrades are needed to improve casting processes. Simultaneously, it is necessary to focus on the introduction, digestion, and absorption of advanced international gate valve products to improve the shortcomings of domestically produced gate valves, such as high material consumption and inflexible operation, in order to catch up with international advanced levels. ③ Water treatment pumps mainly include single-stage single-suction pumps, single-stage double-suction pumps, sewage pumps, screw pumps, deep well pumps, and non-clogging pumps. Sewage pumps are one of the key pieces of equipment in sewage treatment plants. Since the 1980s, technology from Sidritz has been introduced to produce submersible sewage pumps, and technology from KSB has been introduced to produce horizontal and vertical sewage pumps. Later, submersible centrifugal pumps, submersible axial flow pumps, and submersible mixed flow pumps were continuously developed and produced, and are currently widely used. Domestically produced pumps of various types have reached a relatively advanced level and can basically meet the needs of my country's water industry. However, considering the characteristics of the water industry, the efficiency and manufacturing level of pumps should be further developed and improved, such as low-head, high-flow submersible sewage pumps, corrosion-resistant deep well pumps, and high-power submersible pumps. Regarding the generally poor appearance quality of domestically produced pumps, attention should be paid to improving casting processes, improving casting quality, and improving surface treatment technology. To address the issue of short first-time failure time, overall manufacturing precision should be improved; and to address the issue of large leakage, sealing conditions should be improved. 2. Specialized Mechanical Equipment for Water Treatment Specialized mechanical equipment for water treatment includes debris removal machinery, sand removal and sludge scraping machinery, aeration and mixing equipment, thickening and dewatering equipment, chemical dosing and disinfection equipment, biogas utilization equipment, oxidation and desalination equipment, and sludge post-treatment equipment. ① Debris Removal Equipment: Primarily bar screen cleaners and auxiliary devices. After more than a decade of continuous development, domestically produced debris removal equipment has achieved a diverse range of types and specifications, which can be broadly categorized as follows: One type is large bar screens used in large water intake structures such as power plant intakes. Cleaning methods include chain-driven toothed rake type, mobile type, and rotary filter type, mostly imitations of products from Western Europe, the Soviet Union, and Japan. Another type is medium-sized bar screens used in urban water plants. Cleaning methods include chain toothed rake, wire rope toothed rake, telescopic arm type, and mobile type. A third type is fine bar screens, including rotary solid-liquid separators that incorporate the advantages of Japanese products, as well as arc-shaped fine bar screens, straight fine bar screens, stepped bar screens, and cylindrical bar screens. Domestically produced screen cleaning equipment has seen significant improvements in recent years. Stainless steel chains and bars are now used, extending their service life. Safety protection measures have been widely added to the cleaning transmission mechanism; over-torque protection has evolved from simple torque safety pins to hydraulic control protection devices, mechanical over-torque protection devices, and electronic control devices. The positioning accuracy of mobile screen cleaning machines has also been greatly improved. Future efforts should focus on the serialization and standardization of screen cleaning equipment, further improving corrosion resistance, increasing operational reliability, enhancing automation levels, and reducing power consumption. Emphasis should be placed on the development of auxiliary equipment for screenings conveying and packaging, as well as the technology and equipment for odor control in screen wells, to reduce secondary pollution and improve the environment of wastewater treatment plants. ② Sludge and sand removal machinery is crucial for ensuring the normal operation of various sedimentation structures in wastewater treatment plants. Its structure and operation vary depending on the type of tank. Through the accumulation of domestic design and engineering practice, and continuous improvement by manufacturers, it is generally classified into two main categories based on tank shape: circular and rectangular. Based on sludge removal methods, it is divided into two types: scrapers and suction machines. Circular tanks are further differentiated by transmission methods, with some using central drive and others peripheral drive. Rectangular tanks are available in truss-type, chain-driven, and wire rope-driven configurations. In short, with the development of treatment processes, domestically produced scraper and suction machines have evolved into a series of products with various structures and sludge removal methods. The products generally meet the needs of the process. However, there is still a certain gap compared with the international advanced level, mainly reflected in: high material consumption and bulkiness; poor corrosion resistance; high power consumption; low degree of automation; and low degree of serialization and standardization. In the future, we should aim at the standards of advanced foreign companies' products and make corresponding improvements. We should pay attention to developing and promoting center-driven lightweight sludge removal equipment, study the calculation of sludge removal resistance and truss rigidity, experiment with the use of lightweight alloy materials, and develop a circulating scraper-type sludge removal machine with nylon chain drive for rectangular pools. We should also promote vortex sand discharge machines and supporting devices in sand removal machinery. ③ Sludge Treatment Equipment: Primarily dewatering machinery for sludge from water plants and wastewater treatment plants. Significant progress has been made in the development of belt filter presses in China over the past decade, with their main technical and performance characteristics approaching those of similar foreign products. In the development of belt alignment devices, some have incorporated optoelectronic and hydraulic technologies, giving them unique features. However, the quality of domestically produced filter belts still lags behind that of foreign products, and the use of corrosion-resistant materials is not ideal due to price constraints, leading to a higher failure rate. Improvements in appearance design and surface treatment processes are also needed. Plate and frame filter presses are gradually being phased out in water plants due to their high power consumption and low output, but they remain widely used in industrial wastewater treatment. New technologies such as plastic plate and frame filters and pre-pressurized dewatering are now being promoted and used. Currently, centrifugal sludge dewatering machines are being developed and widely applied internationally due to their small footprint, high output, and high degree of automation, leading to a gradual increase in their use in treatment plants. In recent years, a new process has also been developed that combines traditional belt filters with mechanical thickeners, eliminating gravity-fed thickeners. Significant progress has been made in this area, and some centrifugal thickening and dewatering equipment is being actively developed and used domestically. ④ Biogas utilization equipment: including biogas engines, biogas boilers, biogas purification and desulfurization equipment, waste heat boilers, etc., is key equipment for recovering bioenergy from wastewater treatment plants, reducing energy consumption in wastewater treatment, and lowering operating costs. Research and development in this area is limited in my country, and there are few specialized manufacturing enterprises. Currently, the equipment used is mainly imported, making it one of the weakest links in the water industry equipment. ⑤ Chemical dosing and disinfection equipment: These are key pieces of equipment for ensuring the hygiene standards of treated water, especially important in waterworks. Currently, domestically produced chlorinators, metering pumps, ozone generators, and sodium hypochlorite generators can only meet general needs, and their quality lags significantly behind international advanced levels. Internationally, large-capacity ozone generators and chlorine dioxide generators are being used to ensure high-quality drinking water, a field currently lacking in China. With the development of automated chemical dosing in waterworks, corrosion-resistant diaphragm metering pumps that can be connected to computers need urgent research and development. Domestically produced chlorinators also face the challenge of being actively developed into high-level water industry products. ⑥ With the reuse of greywater to solve water resource problems, membrane technology and membrane equipment are being applied more and more widely. The development of electrodialysis, reverse osmosis membranes, and related mechanical devices is urgent. ⑦ Sludge post-treatment is a key area for water treatment equipment with rapid growth and high demand in the coming years. Among these, conveying, turning, drying, and deodorizing machinery and devices are the focus of development. IV. Specialized mechanical equipment to be developed currently: 1. Various forms of decanting machinery for SBR processes. ① 1. Rotary decanter; ② Siphon decanter; ③ Sleeve decanter; ④ Self-operated decanter; ⑤ Elbow-type floating box decanter. 2. Stepped and drum-type fine screen machinery and connected screw conveyors and pressing devices. 3. Cyclone sand discharge machinery and matching sand suction, washing, and discharge devices. 4. New type of plastic steel and composite material horizontal rotating brush and rotary disc aeration machinery. 5. Integrated thickening and dewatering machinery: ① Integrated belt thickening and belt dewatering machine; ② Integrated belt thickening and centrifugal dewatering machine; ③ Integrated drum thickening and belt dewatering machine. 6. Large and medium-sized lightweight radial flow sedimentation tanks with central and peripheral drive sludge scrapers and sludge suction machines. 7. Membrane processing equipment and matching integrated machinery. 8. Sludge post-treatment turning, drying, and fermentation machinery.