The state has issued multiple documents regarding the inclusion of seawater desalination in municipal drinking water. Since the National Development and Reform Commission released the first specialized plan in the field of seawater desalination - the "12th Five-Year Plan for the Development of the Seawater Desalination Industry" at the end of last year, on the 17th of this month, The State Council issued the "12th Five-Year Plan for the Development of the National Marine Economy" (hereinafter referred to as the "Plan"), once again proposing Actively carry out the pilot work of incorporating seawater desalination projects into municipal drinking water projects, and encourage coastal cities and enterprises to use desalinated seawater as production and living water.

It is understood that Qingdao launched a seawater desalination project as early as 2006. Qingdao Baifa Seawater Desalination Co., LTD., which is currently in charge of the largest Sino-foreign joint venture seawater desalination project in the country, once proposed to provide desalinate seawater for drinking to urban residents in July last year.

However, on the 18th, a staff member from the office of the Qingdao Municipal Public Utilities Bureau disclosed to reporters that the goal of incorporating desalinated seawater into municipal water supply has not yet been achieved.

Why has this goal been so slow to be achieved? Is it due to insufficient capital investment? Is it because the price is too high? Is it still due to the immaturity of the technology? With these questions in mind, the reporter conducted an investigation.

The introduction of seawater remains unresolved.

On the 18th, the reporter arrived at the west factory area of Qingdao Alkali Industry Co., Ltd. located at No. 2, Yinjiang Road, Licang District, about 20 kilometers away from Qingdao Railway Station and close to Jiaozhou Bay. The factory area was somewhat desolate. Entering the factory area, a blue sign that read "300 meters to the right of Qingdao First Municipal Seawater Desalination Project Department" led the reporter to "Qingdao Baifa Seawater Desalination Co., LTD."

It is understood that the Qingdao Baifa Seawater Desalination Project was jointly built by the Spanish Abango Group and the city of Qingdao. The project adopts the double-membrane reverse osmosis seawater desalination treatment technology. The construction and research of the project are at the forefront of the country. It was originally planned to be completed and debugged by the end of 2011 and officially put into operation by the end of July 2012. After the project was completed, it was expected to desalinate 100,000 tons of seawater every day. This desalinated water will be directly connected to the municipal water supply network and can meet the daily water needs of 500,000 people.

The reporter saw on the spot that the factory buildings and equipment in the factory area were all very new, but there was no sign of operation. Moreover, a group of technical workers were packing up and leaving the factory area. It has been revealed that the factory area has not yet been put into use.

The reporter noticed that Qingdao Baifa is a joint venture established by Baifisa Company, Qingdao Hairun Water Supply Group Company and Qingdao Alkali Industry Co., LTD. Journalists have attempted to contact the Qingdao Municipal Public Utilities Bureau, Qingdao Alkali Industry, Hairun Water Supply and other parties, but have not received any response.

A local person familiar with the situation in Qingdao disclosed to the reporter that the project's poor progress was also related to the fact that the initially chosen location was not very suitable. It is understood that for a designed total capacity of 100,000 cubic meters per day, the daily demand for seawater should be around 200,000 cubic meters. Such a large scale of seawater introduction must rely on power plants. Although there were later plans to introduce seawater through pipelines, it was not satisfactory either. Therefore, the project has been constantly addressing the problems it faces.

The price system is unreasonable

Although the Baifa seawater desalination project has not yet been put into use, the inclusion of seawater desalination in municipal drinking water has already sparked heated discussions in the island city.

Wang Yuan, a native of Qingdao who lives on Chengde Road, told the reporter that she is very worried about whether the water quality after desalination is suitable for drinking and whether it will harm her health. Wang Xiuliang, a taxi driver living in Licang District, said with a broad mind that as long as others dare to drink it, he has nothing to be afraid of. However, he is worried that the price will be very high, resulting in a situation where he wants to drink but cannot afford it.

"Desalinated seawater connected to the grid for drinking water largely has the issue of public acceptance, but the fundamental problem is still the price." " On the 18th, Wang Haizeng, the vice dean of the College of Chemistry and Chemical Engineering at Ocean University of China and a professor of Marine Chemical Engineering and Technology, said in an interview with reporters. He believes that the current price system for seawater desalination is unreasonable and a new price system should be rationalized and established. The current price for seawater desalination is 4 to 5 yuan per ton. From a professional chemical perspective, Wang Haizeng suggests a price of 2 yuan per ton.

It is understood that the price composition of tap water is very complex, consisting of multiple items such as the basic water price including tax, sewage treatment fees, water resource fees, pipeline network costs, and water conservancy project fees, but all are subsidized by the government.

In response to the current situation where seawater desalination lacks government subsidies and has a significant price difference from tap water, Wang Haizeng proposed that the government should provide certain compensation for seawater desalination. According to the seawater desalination price he calculated, it should include the cost of saving fresh water, the cost of saving land, etc. In his view, tap water requires the construction of large reservoirs on land, which are funded by the state Treasury. Seawater desalination saves land costs, so it should be compensated to a certain extent.

Regarding a series of issues such as whether water prices will be adjusted in the future and how to connect drinking water to the grid, a relevant person from the Qingdao Municipal Public Utilities Bureau stated that all these can only be resolved through hearings, arguments and other means.

Some insiders have analyzed that among all the costs of seawater desalination, energy costs account for more than half. Therefore, professionals suggest that seawater desalination is only feasible when combined with cogeneration.

Industrial water should be used first

Wang Haizeng proposed that Qingdao Power Plant, Huangdao Power Plant and Qingdao Alkali Industry are representatives of the application of seawater desalination to industrial water in Qingdao to seek a circular economy. The view he has always adhered to is that seawater desalination should not be used to supply domestic water first, but to supply industrial water first. Supplying industrial water can save industrial fresh water, which also indirectly guarantees the supply of domestic water.

On the 18th, Liu Naihua, an employee of the Political Work Department of Huadian Qingdao Power Generation Co., LTD., led the reporters to visit the seawater desalination plant area. After passing through the sedimentation tank that seawater must pass through, the reporters arrived at the water treatment workshop. Professional engineer Du Fanghua introduced that the company began to use seawater desalination in 2007. Each set of equipment saves 120 tons of water per hour. Currently, two sets of equipment are in use.

It is understood that the power plant adopts the double-membrane reverse osmosis seawater desalination technology. Through the desalination treatment of seawater, it is used for boiler steam power generation.

In summer, these two sets of equipment can provide about half of the water consumption for the entire power plant. In winter, as both power generation and heating are needed, a large amount of tap water supply is still required. Du Fanghua said, "The company has reserved space for the equipment of the third phase project. If the three sets of equipment operate simultaneously, it is estimated that about 8,856 tons of fresh water can be saved every day."

Du Fanghua believes that although the cost of purchasing tap water for power generation is currently lower, seawater desalination is an inevitable trend. In the future, if the tiered electricity pricing system for industrial use is implemented, the advantages of seawater desalination will become apparent. Moreover, saving fresh water is also a social responsibility of enterprises.

Although some seawater desalination equipment, such as pumps, still need to be imported at present, Du Fanghua and Wang Haizeng share the same view that there are no obstacles to seawater desalination technology and its connection with drinking water pipelines. The main issue is the cost. The higher the salt content of seawater, the greater the power consumption of the pump, which most enterprises may not be able to bear.

Domestic water is harmless.

Du Fanghua stated that although the company specializes in industrial water and has not yet considered the issue of municipal drinking water, it is feasible to introduce desalinated seawater into domestic water. Although there may be some deficiencies in nutrients and certain trace elements need to be adjusted, it will definitely not harm human health.

According to industry insiders, the subsequent treatment of desalinated seawater for drinking mainly includes adding carbon dioxide, calcium hydroxide and sodium hypochlorite, adjusting the PH value, increasing water hardness, enhancing water stability and drinking comfort, and at the same time, disinfecting the water to prevent microbial contamination in the water distribution network.

Drinking desalinated seawater is a new thing in China, but it has been widely applied in many countries. The United States, Australia, Singapore and other countries are all engaged in seawater desalination, and this technology has already matured. Wang Haizeng said.

The Plan also emphasizes that in coastal areas, efforts should be made to vigorously promote the direct use of seawater as industrial water in key industries such as power, chemical engineering, and petrochemicals. In combination with water-saving renovations and new construction projects in high-water-consuming coastal industries, the application of seawater circulation cooling should be vigorously promoted. In coastal cities where conditions permit, promote the use of seawater as a major source of domestic water.

It is learned that in November last year, the seawater desalination project on Lingshan Island in Jiaonan was officially completed and successfully passed the acceptance inspection. The total investment of the Lingshan Island seawater desalination project is 4 million yuan, covering an area of 1,538.55 square meters, with a designed water production capacity of 300 tons per day. This project adopts reverse osmosis technology. The seawater is desalinated through processes such as submersible pumps taking seawater, self-cleaning filters, and reverse osmosis devices. The PH value of the desalinated water is around 7, featuring low salt content and a comfortable taste. After the project is completed, it will provide water for production and daily life for nearly 3,000 soldiers and villagers stationed on Lingshan Island.

Wang Haizeng introduced that at the end of last year, the Development and Reform Commission of Shandong Province initiated a planning project related to the seawater desalination industry and it is currently under study. He suggested that the state should put water resources into the market as a kind of food and consider it as an important aspect of municipal construction.