I. Construction of a Comprehensive Management Mechanism and System for Reclaimed Water Resources

The reuse of reclaimed water is a complex systematic project, involving a wide range of aspects and multiple links, and covering numerous units and departments such as urban planning, construction, environmental protection, and water conservancy. Currently, many cities lack a unified institution to comprehensively coordinate, plan, and manage the utilization of reclaimed water in the city. Departments are fragmented, responsibilities and authorities are unclear, and each operates independently, which has affected the coordinated and scientific development of the reclaimed water utilization industry. Therefore, it is imperative to establish a unified reclaimed water management department.

II. Optimization of Reclaimed Water Treatment and Supply Models

The models for reclaimed water treatment and supply can be divided into the centralized model of "centralized treatment and centralized supply" and the decentralized model of "separate treatment and local reuse".

The centralized model typically uses the effluent from urban sewage treatment plants or sewage that meets the standards for discharge into urban sewers as the water source, which is then treated centrally and the reclaimed water is transported through distribution networks to different water usage sites or user networks. The advantages of the centralized model include economies of scale, lower construction and operation costs for treatment facilities, and stable water quality. However, the centralized model has disadvantages such as high pipeline construction costs, long transportation distances, and difficulty in achieving "separate use" and "high-quality water for high-quality use, low-quality water for low-quality use". When there are multiple uses, the water quality standards for the centralized model need to be determined based on the highest requirements, resulting in "over-treatment" and increased treatment costs.

The decentralized model involves establishing local reclaimed water treatment facilities in relatively independent or scattered residential areas, development zones, resorts, or other public facility clusters, using sewage that meets the standards for discharge into urban sewers as the water source, and achieving local reuse of reclaimed water. The decentralized model has a small scale and does not have the economies of scale in terms of engineering construction and operation. It also has problems such as high management difficulty and unstable operation. However, the decentralized model does not require the construction of large-scale pipelines or long-distance transportation, and the uses are generally single, making it easy to carry out appropriate treatment based on water quality requirements.

Both the centralized and decentralized models have their advantages and disadvantages, but they are not mutually exclusive. A scientific and reasonable solution should be a combination of centralized and decentralized approaches, complementing each other. Therefore, it is necessary to conduct research on the planning methods for the reuse of reclaimed water, and formulate systematic and long-term scientific plans and development strategies based on the characteristics and actual conditions of different regions and cities. The formulation of these plans and strategies often requires a comprehensive management mechanism for reclaimed water resources as a foundation.

III. Construction of the Water Quality Safety Monitoring System for Recycled Water

The development of wastewater recycling in various countries has been rapid. However, there is no complete and all-round supervision system for the water quality of recycled water after it leaves the production plant and reaches the end user. This may lead to the failure of recycled water to meet the usage standards, causing some negative impacts. Since 2000, some cities have gradually begun to build district-level recycled water production systems in newly constructed residential areas. However, in practical applications, some problems have gradually emerged, especially during the usage process, where there have been varying degrees of non-compliance with water quality standards, difficult elimination of odors, and inadequate disinfection, etc., posing hygiene safety hazards.

Therefore, it is necessary to establish a complete water quality safety monitoring system for recycled water, to conduct real-time monitoring of the comprehensive operation status of recycled water facilities and the water quality of recycled water, in order to ensure the stable operation of recycled water facilities and the safety of recycled water quality. For example, entrusting qualified monitoring institutions to monitor the water quality of recycled water can ensure that the water quality of recycled water is qualified, and advanced online water quality monitoring systems can also be used for real-time supervision.

IV. Construction and Improvement of the Water Quality Standards System for Recycled Water

In recent years, the state and many cities have successively formulated a series of policies and standards for the construction and management of recycled water facilities and the utilization of recycled water. However, at present, the utilization of recycled water still has problems such as insufficient policy support and the need for further standardization of industry standards.

V. Development and Process Optimization of Wastewater Recycled Utilization Technologies

The advancement of wastewater recycled utilization technologies is the fundamental guarantee for the safety of recycled water quality. With the continuous deepening of wastewater recycled utilization practices and scientific research, new water quality risk factors and new problems have been continuously discovered, posing higher requirements for the safety of recycled water quality and bringing new challenges.