Due to the improvement of water quality detection ability, China has done a lot of work on the process research of polluted water by using modern water quality detection methods in the 1980s and 1990s. As for oxidants, some people used GC-MS (10) to deeply study the removal of organic matter from water by potassium permanganate oxidation. Study on Purification of Chlorine Dioxide (8) Study on Oxidation of Organic Matter, Chroma, Reduction of Iron, Manganese, Organic Matter and Disinfection by-products (9) Study on Removal of Odor from Water by Potassium Permanganate Compound Agent. In the aspect of activated carbon adsorption process, powdered activated carbon has been applied as a temporary and sudden water pollution treatment measure, and the experiment proves that it is effective to add it in the middle of flocculation tank (1 1)-( 13), and it has also been studied to use it together with KMNO 4. The existing products (14) powdered activated carbon and granular activated carbon water purifier with diatomite precoated membrane filtration have been welcomed by the masses, which have good effects on removing organic and inorganic pollutants in water, reducing halogenated methane and turning the water with Ames test positive mutation into negative. The compulsory standard CJ3023-93 "Activated Carbon Water Purifier" approved by the Ministry of Construction played a very good role at the end of 1993. Biological contact oxidation tank has been widely and deeply studied and has been applied to production. Especially, the contact oxidation tank filled with YDT elastic filler and ceramsite filler was fully studied. They are effective in removing organic pollutants, ammonia nitrogen and algae, but they can't turn raw water with Ames mutation positive into negative. Biological treatment has achieved good results in aeration performance of aeration equipment, dominant bacteria of biofilm, biofilm activity, mathematical model of biofilm, and comparison between YDT elastic packing pool and ceramic particle pool (15). The largest scale of the contact oxidation tank put into operation is 4 million m3/ day.
At the same time, around the advanced treatment of water quality, the experimental study on the combination of activated carbon filtration, conventional water treatment process, biological oxidation and ozone oxidation was carried out, and the removal rate of organic matter in different molecular weight ranges by each unit process was tested, so as to deeply understand the role of each unit process. The detection methods of biodegradable soluble organic carbon BDOC and assimilable organic carbon AOC produced by biological contact oxidation treatment and their research on water quality and water treatment have also been put into practice. It is suggested that the control standards of BDOC and AOC in water treatment are as follows
In 1990s, the conventional water treatment process has made great progress. Compared with polyaluminum, inorganic polymer composite flocculants, polymeric ferric silicate and polymeric aluminum silicate, can improve the efficiency by10-30% (16)-(17), and the automatic current control by adding alum has been used in production. V-type filter characterized by gas-water backwashing of homogeneous filter media has been popularized. The study on strengthening conventional flocculation to remove organic matter and reduce disinfection by-products was carried out. Automatic monitoring of several main water quality indexes in waterworks production and many automatic waterworks have appeared one after another, and membrane technology has developed rapidly in drinking water.
As can be seen from the above introduction, China's water purification technology and water quality testing technology have been in a state of sustainable development since liberation, especially after the reform and opening up. 1993, who put forward the revised edition of the guide to the quality of drinking water, including 136 health-related water quality indicators, while the hygienic standard for drinking water, which is being studied and formulated by the Ministry of health, has more than 90 drinking water indicators and more than 60 water quality indicators, which will further promote the development of water quality testing technology in China and will certainly be beneficial to the development of water purification technology in China.