Industrial wastewater treatment technology

1. Problems and development prospects China's sewage treatment industry started late but developed rapidly, now has made gratifying achievements, which is a fact for all to see, but in the face of the rapid development of China's industry, the amount of industrial production wastewater is also growing year by year, although the current scale of sewage treatment plant construction can basically meet the industrial sewage treatment. However, there is still a long distance from deep purification and recycling. Sewage treatment is a worldwide problem, the sewage treatment capacity of developed countries can reach 70% ~ 80%, China's sewage treatment capacity can only reach 50% ~ 60%, the rest of the treatment can not still rely on direct discharge.

1.1 Construction and operation of sewage treatment plants In order to meet the needs of industrial development, in recent years, the state has built more than 500 standardized sewage treatment plants, sewage treatment capacity can not meet the current stage of sewage production, regional economic development of different sewage treatment plants investment scale is also different, most of the sewage treatment industry belongs to public institutions. It is not a profit-oriented industry, and its main role is reflected in public welfare and environmental protection, so the construction and operation of sewage treatment still needs to rely on the support and macro-control of the state and local governments. Affected by the economic development of local enterprises, the government's tax revenue will also fluctuate, if the construction and operation of sewage treatment plants can not be perfected and developed, the direct discharge of sewage will cause incalculable harm to the local living environment.

1.2 Upgrading of sewage treatment equipment Most of the equipment installed and operated in the existing sewage treatment plant tends to be aging and traditional, a large number of operating equipment is imported from abroad, and the economic costs caused by equipment aging, treatment efficiency decline, equipment damage and other problems in the operation process are huge, and the introduction cost of new equipment is high due to the influence of intellectual property rights. In the face of the annual growth trend of industrial sewage volume, China's independent development will be imminent, which is a more severe challenge, the development of domestic sewage treatment technology has been tested, training professional and technical personnel to develop China's independent sewage treatment technology has become the first issue, in the continuous learning of foreign peer experience, Independent innovation and development of independent intellectual property rights of sewage treatment equipment, fully complement the pressure of sewage treatment. Equipment transformation: The traditional sewage treatment equipment has achieved considerable results in recent years in our country, and gained rich experience through actual debugging operation. However, with the shortage of water resources in China, the deterioration of the environment, the perfection of the national law, the sewage treatment requirements are becoming more and more strict and meticulous, and the development and introduction of new technologies will gradually replace traditional equipment. Membrane technology, ultrafiltration, electroadsorption salt removal technology, chitosan derivative technology, biochemical bed, electrocatalytic oxidation, mvr and other parts of the modern technology with energy saving, green, recycling, efficient is the goal of our future reform.

1.3 Sewage deodorization In the process of sewage treatment, the sewage itself has a strong volatility will produce different kinds of odor, in the process of entering the physicochemical and biochemical system, the change of temperature promotes the dispersion of odor. For example, when sewage enters the aerobic and anaerobic sections, because the metabolic temperature of activated sludge is generally above 20 ° C or even higher, coupled with the aeration of Roots fan directly affects the Brownian motion of harmful gases, resulting in serious damage to the air environment of residential areas and working areas around the factory.

1.4 Sludge treatment Sludge mainly exists in the biochemical system, and the bottom of the other process section pool will regularly produce sludge with higher concentration. The traditional treatment method is to collect this part of sludge into the sludge thickening tank, and then add flocculant and other agents to treat it into the mud press filter and bag for preservation. The traditional mud press is mainly plate and frame type mud press, which has low operation difficulty and low automation, and the water removal of sludge needs to be improved. Gradually, it will be replaced by a spiral sludge filter press, because it has a more efficient water removal effect, convenient operation, time-saving efficiency, but the price is more expensive.

There are two main ways to treat sludge: incineration and deep burial. In essence, it has not reached harmless, and the development of new technologies is concentrated in the direction of natural and harmless sludge cultivation by loach method and plant absorption. Although the distance from actual industrialization is still far away, we must make efforts to green and harmless.