Planned investment in water and sewage treatment is going on to maintain and improve urban functions toward 21st century. The water treatment already widely spread has problems of quality rather than quantity, and the sewage treatment has both problems of quantity and quality. On the other hand, remarkable progress in electronics has brought a variety of functions in hardware and has brought advanced image processing, artificial intelligence, and diagnostic technologies in software, which are actively being applied to water and sewage works. This paper outlines the administrative problems and electrical/instrumentation system technologies.

The surrounding of water and sewage treatment is changing: consumers demand high-quality service and the staffs of local governments demand improvement in working environment.On the other hand, rapid progress in information processing and communication technologies has made possible to structure high-grade integrated information systems.
The paper rearranges the needs considering connection between the problems of water and sewage treatment and the introduction of high-grade information systems, and proposes a suitable advanced system.

Process automation in water and sewage treatment is composed of electrical control, instrumentation, and computer systems. However, lack of unity in interfaces between systems, complicated system configuration, and insufficient consideration of user's individuality and requirements-these have been pointed out so far.
This paper introduces an "integrated control system" recently developed by Fuji Electric in which an electrical system, instrumentation, and a computer system are closely combined.

Supervisory control systems are now indispensable for the smooth operation of waterworks. Fuji Electric developed a large-scale supervisory control system, new FAINS-1000 series, based on the concept of CIM. This is a 5-level hierarchical system from a management level down to a local control level regarding the water service as a water-manufacturing company.
Small-scale utilities desire reliable and economical systems easy to maintain. This article introduces a small-scale supervisory control system composed of photosensors, work stations an intelligent control center, and others.

The erection of sewage treatment plants is carried out step by step for a long period. Therefore, supervisory control systems for them should be capable of increasing and extending to match the fiscal year plan and also be progressive. Moreover, economical, reliable and high-quality systems are required aiming at securing reliability in plant operation and realizing efficient maintenance. Fuji Electric, to meet these needs, has put a supervisory control system, "New FAINS series," on the market, which can cope with small-to large-scale plants on the basis of advanced computer and communication technologies.

Application of AI has proceeded for enhancing plant operation management in water and sewage works. Fuji Electric has developed AI tools such as EIXAX for control, FRUITAX for fuzzy control, COMEX for diagnosis, and φ NET for FA. This paper describes an application of intelligent optimum control (KOCP) to service water control, which was developed on the basis of EIXAX and connected with a mathermatical planning model, an application of FRUITAX to rain water pump control in a sewageworks, and an application of COMEX to sludge treatment operation support.

Water service has achieved a hight rate of diffusion and problems now consist in how to switch over from quantity to quality and how to strengthen management bases. Fuji Electric has developed a support system to solve these problems, and this paper describes its functions and effects of introduction in three cases of planning, plant operation, and maintenance.
Particularly with regard to the maintenance support system, it refers to area analyses for water cutting off using an expert system under development.

This paper describes support systems with personal computers to support planning, designing, and maintenance. The planning support system stores various plan information in the data base and provides information in line with planning. The designing support system helps determination of piping routes and automatic drawing of vertical section of culverts. The maintenance support system helps sewerage record management, flush-toilet diffusion management, service area management, and equipment maintenance management. It also refers to document management system to smoothly manage documents handled in various works.

This paper describes the analyzing method, techniques applied, and analysis examples of water quality, mainly of residual chlorine concentration.
In particular, it introduces the dynamic analysis of water quality to obtain the variation with time of water quality and a new computerized method of chlorine injection control using it.
Study on the system technology of water quality has just been started and many points remain not clear. It is expected that the application of the above techniques to actual systems will clarify them.

As the application of information networks was promoted in water and sewage works, efficient planning and designing, simplified installation, short construction time and easy maintenance have been desired. Fuji Electric has completed a local network system, FALONET (Fuji Aqua LOcal NETwork) in which system units are incorporated in the local panel, control center, and HV switchboard and execute serial transmission. The paper describes the system configuration, function, features, and applications of the FALONET.

Recent eutrophication in enclosed water areas has been a serious social problem, and removal of nitrogen and phosphorus and automatic measurement are urgently required. Fuji Electric has developed four new types of automatic water quality analyzers for water and sewage works: ammonia analyzer, total nitrogen analyzer, three specias of nitrogenous compound (T-N, NO₂-N, NO₃-N) analyzer, total phosphorus analyzer.
These are based on unique measuring methods suitable for automatic measurement. The paper describes the measuring method of each type and results of specimen measurement.

The inspection of water quality is a very complicated work which includes many inspection items and requires much time and labor even for pre-treatment before analysis. To solve this problem, Fuji Electric has developed a robot for water quality analysis with a built-in photoelectric photometer and printer in the automated pre-treatment unit so that pre-treatment to water quality analysis and data printout can automatically be carried out only by setting 6 to 12 specimens of water in the equipment. The equipment conforms to the method for water testing and gives high-repeatability data without individual variation.

Fuji Electric has developed a sewage treatment system using biotechnology remarkably progressed in recent years and continues demonstration in a pliot plant scale. This system composed of an anaerobic bioreactor, aerobic bioreactor, and anaerobic bioreactor for sludge treatment. The major features are (1) labor saving and low cost, (2) reduced sludge production, (3) superior effluent quality, (4) easy maintenance, and others.
Owing to these merits, this system is suitable for small-scale sewage works for which there is a growing need.

As the water quality of water souces got worse, problems in potable water, such as unpleasant oder, have been noticed. High-grade treatments to cope with this situation, such as ozonization, activated-carbon treatment, and biological treatment, are going to be introduced in addition to the conventional treatment.
This paper outlines high-grade treatments and the configuration and function of an ozonizing system and also experiments on odor material decomposition by ozone, characteristics of mixing in contact basins and catalysts for exhaust ozone decomposition.

Sludge produced in sewage-works and other waste water treatments is generally stabilized by dewatering. Current dewatering techniques, mainly mechanical, use presses and filters to extract water from sludge. However, dewatering rate is limited with such methods.
Fuji Electric has developed a new sludge dewatering system much more efficient than conventional systems. The use of electric-osmosis has realized this economical and excellent dewatering system. This paper describes an outline of the system and its economical efficiency.

Speed control technology for AC motors has made a remarkable progress, and VVVF inverters and other applications have been in wide use. As transistor VVVF inverter technology advanced, new motor control systems have been applied also in water and sewage works. To meet the market needs and realize reliable motor control, Fuji Electric has developed new products and set up their application technology in line harmonicless VVVF inverters, VVVF inverters for battery driven motor valves, and high-efficiency centrifugal sludge dewatering equipment.