10 advanced technologies in the water treatment industry

1. Membrane technology

Membrane separation methods are commonly used in microfiltration, nanofiltration, ultrafiltration and reverse osmosis. Because membrane technology does not introduce other impurities in the treatment process, it can realize the separation of large molecules and small molecules, so it is often used for the recovery of various macromolecular raw materials.

Such as the use of ultrafiltration technology to recover printing and dyeing wastewater of polyvinyl alcohol slurry. At present, the main difficulties that limit the application and popularization of membrane technology are high cost, short life, easy to be polluted and blocked by scale. With the development of membrane production technology, membrane technology will be more and more applied in the field of wastewater treatment.

2. Iron carbon micro-electrolysis treatment technology

Iron-carbon microelectrolysis method is a good process for wastewater treatment using the reaction principle of Fe/C galvanic cells, also known as internal electrolysis method and iron filings filtration method. The iron-carbon microelectrolysis method is a comprehensive effect of electrochemical REDOX, electrochemical electroconcentration of floc, condensation of electrochemical reaction products, adsorption of new floc and bed filtration, among which REDOX, electric adhesion and condensation are the main effects.

When the iron filings are immersed in the wastewater containing a large number of electrolytes, countless tiny galvanic cells are formed. After the coke is added to the iron filings, the iron filings contact with the coke particles to further form large galvanic cells, so that the iron filings are corroded on the basis of micro galvanic cells and corroded by large galvanic cells, thus speeding up the electrochemical reaction.

This method has many advantages, such as wide application range, good treatment effect, long service life, low cost and easy operation and maintenance, and uses waste iron filings as raw materials, and does not need to consume power resources, and has the significance of "treating waste with waste". At present, iron-carbon micro-electrolysis technology has been widely used in dyeing, pesticide/pharmaceutical, heavy metal, petrochemical and oil waste water and landfill leachate treatment, and has achieved good results.

3.Fenton and Fenton-like oxidation process

A typical Fenton reagent is produced by the decomposition of H2O2 catalyzed by Fe2+ to ˙OH, which leads to the oxidative degradation of organic matter. As Fenton process takes a long time to treat wastewater, it uses a large number of test doses, and excessive Fe2+ will increase COD in the treated wastewater and produce secondary pollution.

In recent years, ultraviolet light and visible light have been introduced into the Fenton system, and other transition metals have been studied to replace Fe2+. These methods can significantly enhance the oxidative degradation ability of Fenton reagent on organic matter, reduce the amount of Fenton reagent and reduce the treatment cost, collectively referred to as Fenton-like reaction.

Fenton process has mild reaction conditions, simple equipment and wide application range. It can be used as a separate treatment technology, or combined with other methods, such as coagulation precipitation, activated carbon, biological treatment, etc., as a pretreatment or advanced treatment method of refractory organic wastewater.

4. Ozone oxidation

Ozone process of a pharmaceutical wastewater project

Ozone is a strong oxidizing agent, which reacts quickly with reduced pollutants, is convenient to use, does not produce secondary pollution, and can be used for sewage disinfection, color removal, deodorization, removal of organic matter and reduction of COD. Using ozone oxidation alone is expensive and expensive, and its oxidation reaction is selective, and the oxidation effect on some halogenated hydrocarbons and pesticides is relatively poor.

To this end, in recent years, the development of related combination technologies aimed at improving the efficiency of ozone oxidation, in which UV/O3, H2O2/O3, UV/H2O2/O3 and other combination methods can not only improve the oxidation rate and efficiency, but also can oxidize organic matter that is difficult to oxidize and degrade when ozone acts alone. Due to the low solubility of ozone in water, low production efficiency and high energy consumption, increasing the solubility of ozone in water, improving the utilization rate of ozone, and developing high efficiency and low energy consumption ozone generation devices have become the main research directions.

5. Magnetic separation technology

Magnetic separation technology is a new type of water treatment technology developed in recent years, which uses magnetic separation of impurity particles in wastewater. For non-magnetic or weakly magnetic particles in water, magnetic inoculation technology can be used to make them magnetic.

There are three methods of magnetic separation technology used in wastewater treatment: direct magnetic separation method, indirect magnetic separation method and microbial magnetic separation method.