Recently, Tian Xufeng, chairman of Hezhongsi (Beijing) Environmental Engineering Co., Ltd., was interviewed by Xinhua News Agency reporters on the topic of zero wastewater discharge, providing reference answers based on the company's achievements in the zero wastewater discharge of energy and industrial wastewater in the Yellow River Basin. (Original link attached below)

The full text is as follows:

Concentrated brine treatment has always been a technical bottleneck restricting the sustainable development of coal chemical industry. With the tightening of national and local environmental protection policies, this contradiction is particularly prominent for coal chemical and energy enterprises located in the Yellow River Basin, which suffers from severe water shortage and fragile ecological environment.

Through years of technological innovation, Hezhongsi (Beijing) Environmental Engineering Co., Ltd. has developed evaporation crystallization technology suitable for China's national conditions. This technology not only solves the pollution discharge of concentrated brine, but also turns waste into useful resources through the technology of graded salt separation, truly achieving zero wastewater discharge. This technology not only transforms polluting enterprises from a burden into a profit-making entity, but also reduces the total investment of water treatment projects by at least 50%. The technology has been successfully applied to many national major energy projects, creating many industry benchmark projects.

Evaporation crystallization technology has therefore been included in the "2022 National Advanced Pollution Control Technology Catalog" of the Ministry of Ecology and Environment. Hezhongsi was selected as the "supporting unit" of the Ministry of Industry and Information Technology's "Major Environmental Protection Technologies and Equipment Encouraged by the State (2017)", and was rated as a national high-tech enterprise and a specialized and new "small giant" enterprise in Beijing.

The reporter recently interviewed Tian Xufeng, chairman of Hezhongsi, with a series of questions.

Reporter: What is the true meaning of "zero discharge"?

Tian Xufeng: For industrial wastewater treatment, "zero discharge" refers to the use of reasonable water treatment technologies and processes to purify and recycle wastewater as much as possible, and to utilize valuable substances in wastewater as resources.

Factors affecting the effect of "zero discharge" include process technology, equipment selection, cleaning cycle, etc., and sufficient technical strength and rich engineering experience are also required.

For example, reverse osmosis (RO), because of its mature technology and high separation efficiency, is widely used in industrial wastewater treatment systems. However, this pressure-driven membrane process still produces concentrated brine. The discharge of concentrated brine not only wastes resources but also seriously pollutes the environment, so it must be further treated. Therefore, "zero discharge" cannot be achieved by a single technology; reasonable selection and matching of different processes are needed, and even some processes may need to be tailor-made.

The selection of equipment is also the same. Reasonable equipment selection can ensure stable system operation, reduce system downtime for equipment maintenance, and thus reduce the discharge of accidental wastewater.

The cleaning cycle is also a very important factor, which is a direct reflection of the good or bad results of the entire system operation. A well-designed system can ensure that the system is cleaned only during major overhauls once or twice a year, while a poorly designed system will result in short cleaning cycles, leading to system downtime and wastewater discharge. This also requires sufficient engineering experience accumulation.

In addition, zero discharge also needs to consider investment and operating costs. Overly complex and conservative processes lead to high system investment and operating costs, which customers cannot accept, and zero discharge has no practical value or significance.

Conversely, blindly pursuing and selecting low-cost systems will result in the system being unable to operate normally, and the customer's investment will be worthless, and the goal of zero discharge cannot be achieved.

Therefore, to achieve true "zero discharge", it is necessary to select reasonable processes and equipment, have strong engineering experience to ensure this, and also consider the cost, so that customers can buy with confidence, afford it, and use it. Any mistake in any link may lead to failure, failing to ensure "zero discharge", resulting in the project ultimately becoming "near-zero discharge" or unable to operate normally.

Reporter: The difficulty of zero discharge of industrial wastewater is the treatment of concentrated brine. What are the current processes for concentrated brine treatment?

Tian Xufeng: Brine concentration is the process of removing water from brine to increase the concentration of salt. The main current technologies include: membrane concentration, membrane distillation, electrodialysis, evaporation crystallization, etc.

Membrane concentration and separation processes include reverse osmosis and nanofiltration technologies, which separate water from brine through semi-permeable membranes to achieve concentration or separation. Membrane concentration and separation processes have lower investment costs, but higher operating and maintenance costs. Membrane distillation technology has high investment and operating costs and limited applicable conditions, so it is rarely used. Electrodialysis uses ion exchange membranes' selective permeability under the action of an electric field to achieve desalination, concentration, and separation of solutions.

In industrial wastewater zero discharge systems, these technologies are mainly used for concentration and reduction, and partial recovery of wastewater. As the concentration of brine increases, the use of these technologies is increasingly limited, or even unusable.

Evaporation process is to heat and evaporate the brine, so that the water evaporates, and the remaining salt is concentrated. Crystallization process is to heat the brine to saturation, so that the salt crystallizes, and after separating the crystals, through the reasonable selection and matching of evaporation and crystallization technologies, all wastewater can be recovered and the salt in the wastewater can be utilized as resources, thus achieving "zero discharge" of industrial wastewater.

Reporter: In which projects is evaporation crystallization technology currently applied?

Tian Xufeng: Asia's largest coal chemical park zero discharge project - National Energy Group Ningdong Mining Area mine water and coal chemical wastewater treatment and utilization project. This project has complex and variable wastewater components. Zero discharge is achieved through membrane concentration and reduction, graded salt separation, and evaporation crystallization as the core, obtaining 98.5% sodium chloride and 99% anhydrous sodium sulfate. The product water reaches the primary reclaimed water quality standard. After the project was put into operation, the overall fresh water consumption of the park was reduced by 38.27%.

The first salt separation zero discharge project in the power industry - Guodi Hanchuan Power Plant desulfurization wastewater zero discharge project. The desulfurization wastewater MVR evaporation crystallization technology provided by our company can be effectively combined with salt separation technology. Under the condition of meeting zero wastewater discharge, the solid waste is finally converted into refined secondary industrial salt. Compared with traditional technologies, the MVR evaporation crystallization system is more energy-efficient and environmentally friendly, saving about 60% of operating costs compared with traditional multiple-effect evaporators.

In the field of new energy, we have undertaken the first zero discharge project for wastewater from graphene negative electrode materials in China - the evaporation crystallization project of the wastewater treatment plant construction project in Laixi City, Qingdao, Graphite New Materials Industry Cluster Zone. This project uses unique process technology to recover high value-added calcium chloride, and is the only project in this field in China that has been in continuous operation for more than 3 years.

We have also undertaken the currently under-construction world's largest new energy lithium battery cathode material project - Ningxia Baofeng Energy Storage Materials Co., Ltd. battery material industry chain demonstration project. The completion of this project can recover high value-added ammonium sulfate. In the design, we adopt advanced schemes, short process flow, and can reduce operating costs by 20%.

In the coal mining industry, we have undertaken numerous mine water projects. For example, the mine water upgrading and treatment project in the Bulienta area of Shenhua Coal. In this project, we used our independently developed cryogenic fractional crystallization process package, which can significantly extend the freezing operation time while reducing energy consumption by more than 20%.

We have always focused on the pollution discharge of national energy enterprises in the Yellow River Basin, and our commitment to our clients is "never discharge a single drop of water into the Yellow River".

To date, the company has put into operation more than 30 "zero-discharge" projects in China, all of which are operating safely and stably and have received positive feedback from owners.

Reporter: What do you think are the advantages of your company frequently winning major projects?

Tian Xufeng: Since its establishment 20 years ago, the company has always attached importance to technological innovation and equipment research and development. It has invested 60 million yuan to build laboratories, pilot plants, and production bases. It has independently developed high-flow filtration systems, a full series of pollution index measuring instruments, special reagents for evaporation crystallization systems, and two industry-leading high-salt wastewater treatment technologies, including freezing and seeding methods. Relying on the developed concentrated crystallization and fractional salt extraction and resource utilization technology equipment and coal chemical wastewater deep treatment technology equipment, the company was selected as one of the first batch of "major environmental protection technology equipment supporting units encouraged by the Ministry of Industry and Information Technology". The company's developed "industrial high-salt wastewater evaporation crystallization and high-value resource utilization technology" has been included in the "Beijing Energy-Saving Technology Product Recommendation Catalog (2020 Edition)" and the "National Advanced Pollution Prevention and Control Demonstration Technology List". At the same time, the company has participated in the compilation of 7 national and industry standards for industrial water treatment, and has applied for nearly 200 patents, including 11 authorized invention patents.

Combining years of practical experience in the water treatment industry, we have set our sights on the goal of zero discharge and chosen to make breakthroughs in the field of evaporation crystallization technology. Based on the introduction of advanced foreign technologies, we have improved them in combination with domestic industrial realities. We have developed efficient, energy-saving, and economical evaporation crystallization system process packages for coal chemical, mine, and power plant wastewater treatment, forming a zero-discharge solution for high-salt wastewater, and successfully applied it in many benchmark projects.

It is worth mentioning that the evaporation crystallization technology we developed has reduced the total investment of system projects by at least 50% and has formed a new technological route suitable for China's industrial and operating environment, filling a domestic gap.

Reporter: In your spare time, you particularly enjoy skiing. Does this reflect a challenging, adventurous, and hardworking spirit within you?

Tian Xufeng: Skiing is indeed a very challenging and adventurous sport, and that's why I love it. But the real insight skiing has given me is control—controlling speed and controlling risk. The process of skiing is not just about speeding; it's also about controlling risk, achieving maximum enjoyment within a reasonable speed and path!

This is actually the same as running a business. Business development is not about being faster or bigger, but about finding your strengths and developing at a controllable speed on the right path to create products and projects you like.

Through the conversation with Tian Xufeng, the reporter believes that with the increasing environmental awareness of the people and the government's emphasis on environmental protection, wastewater treatment and discharge standards will become increasingly stringent. The huge market demand not only brings unprecedented opportunities and challenges to the water treatment industry, but also promotes the vigorous development of the water treatment industry and accelerates the upgrading of water treatment technologies. It is believed that in the near future, we will see more water treatment companies like Hezhongsi, daring to explore and innovate, enabling more polluting enterprises to achieve zero wastewater discharge, and enabling China's water treatment industry to move from a water treatment powerhouse to a strong water treatment country. Wu Xiaowei )