The investment cost and operating cost of "zero discharge" of industrial wastewater are high, and it is difficult to promote and apply. According to data, investment in some "zero-discharge" technologies will account for about half of the total environmental protection investment of the project. After operation, the treatment cost of organic wastewater per ton exceeds 5 yuan, and the treatment cost of high-salt wastewater is more than 38 yuan per ton.
The "zero discharge" of industrial wastewater consumes a lot of energy, and the cost performance cannot be balanced. As the concentration of substances in sewage increases, the saturated vapor pressure gradually decreases, and the evaporation rate slows down accordingly. Although the technology of steam-driven evaporation and crystallization can achieve the goal of "zero emission", it will consume more electric energy and heat energy. "Emissions" technology cannot achieve a higher production balance.
The level of domestic companies varies from good to bad, the market is chaotic, and there are few excellent domestic typical cases. Although "Zero Emissions" has a history of several decades, its application and promotion time in the country is relatively short. The market and technology are not yet mature. Moreover, this technology has high economic costs. Without policy support and supervision, it will cause negative effects.