Wastewater needs to be given a new life. Even the last drop of wastewater can be a valuable resource.
China has experienced significant urbanization for decades, and city inhabitants now outnumber farmers. Approximately 52% of China's population now resides in cities. The Chinese government expects this number to reach 70% by 2025. This change has so far raised a host of challenging issues for social and economic planners as well as a number of urgent environmental concerns. 250 million newly urbanized people would need to figure out how to get to work, heat their homes, have access to enough water for daily use, and dispose of their trash. Such design and planning issues will significantly impact China's development, particularly its efforts to reduce greenhouse gas emissions and other forms of pollution in the air, water, and land.
As a result of its accelerated economic growth, China has shifted its attention and expanded its efforts in recent years to tackle the high levels of environmental pollution in the country. China launched an attack on pollution and set aside imposing funds to fight it, with more than half of the money going toward water pollution. The government announced the Water Pollution Prevention and Control Action Plan with the goal of stopping significantly polluting sectors from compromising water supplies.
China's most recent environmental assessment, however, is still unfavorable, claiming that 28.8% of major rivers and 61.5% of groundwater are "not fit for human contact." Industrial and agricultural businesses are mostly to blame for the contamination, and the ensuing pollution has seeped into the earth's water table. According to the research, useable and safe water is hard to come by, and more than half of China's cities have water shortages, particularly in the arid north. China only has 7% of the world's water resources despite having 20% of the world's population. Additionally, the distribution of these water resources across provinces and administrative areas is unequal and unreliable.
The water problems in China are massive. China experiences a 50 billion m3 annual water shortage on average. Beijing and other cities in the Hai River basin will still have less water than thresholds of water scarcity recognized internationally, notwithstanding the South-to-North Water Transfer project.
High-quality wastewater treatment technologies are definitely needed in China in order to reverse the situation of its severe water pollution. The fact that the bulk of wastewater treatment procedures in China relies on lengthy aeration is a big problem in terms of energy management. Traditional prolonged aeration is still used by over two-thirds of existing treatment facilities, and this method uses 50% more energy than anaerobic sludge digestion. With 3,910 wastewater treatment facilities as of 2016, China, which has pioneered a number of wastewater treatment technologies, currently has the second-highest drainage processing capacity in the world. Three of these technologies are used by 80 % of these facilities to remove pollutants from sewage:
Biofilm procedures, membrane bioreactors (MBR), natural biologic treatment systems (such as artificial wetlands), and anaerobic biologic treatment procedures are less commonly used. Depending on the kind of wastewater, cost, and other criteria, a specific treatment method is chosen. Sludge disposal is another problem. The majority of municipal wastewater treatment procedures lack methods for stabilizing extra sludge. The only treatment for the extra sludge is dewatering and/or thickening, and it is primarily disposed of in landfills. Sludge is only occasionally used by wastewater treatment procedures in agriculture and other sectors. Advanced wastewater treatment technologies and maybe the very expensive zero liquid discharge (ZLD) systems for the industrial wastewater sector will become economically viable if wastewater discharge rules are tightened and wastewater treatment and discharge prices are raised.
As an alternate ecological approach to handling runoff problems and flood water retention, China also uses "constructed wetlands." Constructed wetlands are artificial biological ecosystems that combine hydrology, vegetation, and flow routes to effectively remove pathogens, soluble solids, nitrogen, phosphorus, heavy metals, and organic contaminants. Depending on the needs of the location, they can be built and tailored by biotic or abiotic mechanisms to target particular kinds of naturally occurring pollutants. The least expensive way of wastewater treatment is constructed wetland systems, which cost between 30 and 50 % less than traditional treatment techniques.
Additionally, China's rural areas experience the worst water shortages and pollution. The distribution of wastewater treatment in rural areas is inadequate. More than 90% of villages and townships lack adequate drainage and sewerage services, and only 3% have wastewater treatment facilities. There are 300 million people living in rural areas who lack access to clean water. Therefore, the need for efficient and affordable treatment facilities is greatest in rural areas. Smaller, decentralized facilities would be the most practical solution given the lack of infrastructure, the dispersed population, and geographic constraints. In China, domestic wastewater discharge has gradually surpassed industrial wastewater discharge. For instance, over 50% of the total amount of wastewater discharged came from home sources. This percentage had increased along the line.
The State Council of China has released an ambitious plan to stop the decline in water quality and enhance the management of water resources across China in an effort to significantly alter this situation. The Action Plan for Water Pollution Prevention establishes progressive goals for the following five, fifteen, and thirty-five years and offers a comprehensive policy agenda that includes, among other things, market-based incentives, stricter regulation of industry effluent discharges, investment in new water treatment facilities, and promotion of cleaner and more efficient technologies. Although it is unclear how much of this ambitious objective will be accomplished in the periods anticipated by the Chinese government, the Plan calls for a fundamental change in how the country regulates water quality.
The Plan sets forth precise targets for water quality for the years 2025 and 2030, with the ultimate objective of achieving total improvement by 2050. According to the Plan, 93% of the drinking water sources in prefecture-level cities and 70% of the water in China's seven major watersheds must both achieve acceptable standards by 2025. The Plan increases these goals to 75% and 95%, respectively, by 2030. The Plan also asks for the removal of "black and odorous water bodies" in prefecture-level cities by 2030 and a reduction in their prevalence to less than 10% by 2025. With major new projects to be located in preferred development areas and the decommissioning of certain types of polluting facilities (such as metals, paper, and chemical production) that are currently located in settled areas, water resource capacity will become an integral factor in land-use planning and zoning under the Plan. The Plan outlines financial incentives to cut back on water use in addition to its regulatory policies. These include accelerating an ongoing reform of the water pricing system, enacting new taxes, and creating favorable financial incentives for facilities to adopt water-saving methods and technologies.
The National Development and Reform Commission, the Ministry of Science and Technology, the Ministry of Industry and Information Technology, the Ministry of Finance, the Ministry of Land and Resources, the Ministry of Housing and Urban-Rural Development, the Ministry of Transport, the Ministry of Water Resources, the Ministry of Agriculture, the Ministry of National Health and Family Services, and more than 12 other government departments collaborated to create this new plan.
The Plan outlines 10 main actions that can be further divided into 38 smaller actions, each of which has a deadline and a list of the relevant government agencies. The Plan generally addresses the following four major actions:
Goals and Targets
China’s water environment quality will gradually improve by 2025:
The “Pollutant Discharge Control” program area has four major components:
Key Water Bodies and Locations
With rigorous emission limitations and more public and governmental oversight, the new plan places strict controls on companies that produce pollution. Additionally, it has a list of targeted small factories in ten industries that must adhere to pertinent national policy, standards, and industrial legislation or face closure:
The ten largest polluting sectors listed below are being targeted for technological advancements, emission reductions, and clean production:
The Plan includes various actions that have some of the aforementioned and other industries as their targets. Additionally, the Plan addresses pollution reduction, increased agricultural water efficiency, municipal water use, coastal water management, and general ecological environment conservation.