In the coating manufacturing industry, the production of various coating types such as water-based coatings, solvent-based coatings and powder coatings will inevitably produce a certain amount of industrial wastewater, that is, paint production wastewater, which has attracted much attention because of its difficult treatment.
First of all, the coating production wastewater mainly comes from three aspects: first, the wastewater generated in the raw material production process, such as resin synthesis wastewater, which has a very high concentration and poor biodegradability, its color is high, and the COD concentration often exceeds 10000mg/L, containing a variety of pollutants;
The second is the cleaning wastewater of production line equipment and flooring, such as water-based paint cleaning wastewater, which contains polymers, additives, additives, etc., and the water quality is relatively turbid;
Finally, there is low-concentration wastewater, including domestic wastewater, laboratory wastewater, and initial rainwater.
Specifically, the wastewater composition of a company contains benzene, esters, alcohols and a small amount of solid substances, and the COD concentration is as high as 150,000mg/L, but the amount of water is small.
Due to its source and pollutant characteristics, coating production wastewater not only has a high concentration, but also has a benzene ring and heterocyclic structure, which has strong stability, difficult degradation, complex composition and high pollutant concentration, and belongs to industrial wastewater with poor biodegradability and complex composition. In addition, wastewater discharge is intermittent, and the water quality and quantity fluctuate greatly, which is easy to cause impact on the wastewater treatment system.
For this kind of wastewater treatment, Liyuan Environmental Protection recommends the comprehensive wastewater treatment method of "physicochemical treatment + biochemical treatment + advanced treatment".
Firstly, the concentration of pollutants in wastewater was reduced through physicochemical treatment, its biodegradability was improved, and the high-concentration wastewater was mixed with other low-concentration wastewater to meet the requirements of biochemical treatment. Commonly used physicochemical treatment methods include iron-carbon microelectrolysis and Fenton oxidation, which operate under acidic conditions and can effectively degrade macromolecular pollutants into small molecule pollutants, significantly improving the biodegradability of wastewater.
Then, in the biochemical treatment stage, anaerobic reactors are used to further reduce the concentration of pollutants and improve biodegradability, while being able to treat high concentrations of COD and degrade organic matter into methane and carbon dioxide. For example, in a case, the COD concentration of the influent water of the hydrolysis acidification tank is 14000mg/L, and the COD concentration of the influent water of the UASB reactor is 9000-10000mg/L.
The UASB reactor, also known as the up-flow anaerobic sludge bed reactor, is an efficient anaerobic biological treatment technology, which is widely used in organic wastewater treatment. It works by using anaerobic microorganisms to decompose organic matter in wastewater in the absence of oxygen, producing biogas and removing pollutants. The UASB reactor has a simple structure, no mechanical stirring, and high treatment efficiency, especially suitable for the treatment of high-concentration organic wastewater.
The main feature of the UASB reactor is the formation of a sludge bed, in which a high concentration of microorganisms is able to efficiently convert organic matter into biogas and water. The reactor is divided into a reaction zone, a three-phase separation zone and a gas chamber, where the reaction zone is the place where microorganisms degrade organic matter, and the three-phase separation zone is responsible for separating gases, liquids and solids, and the gas chamber is used to collect biogas. UASB reactor has a small footprint and low operating costs, and is one of the important technologies in the field of wastewater treatment.
The advantage of the UASB reactor is its high treatment efficiency and low-cost operation, which effectively removes organic pollutants from wastewater while producing usable biogas. In addition, the UASB reactor has a simple structure, is easy to operate and maintain, and is suitable for a variety of industrial wastewater treatment occasions. Due to its excellent performance and economic benefits, UASB reactors have been widely used at home and abroad.
Finally, through aerobic biological treatment, such as contact oxidation method, the paint production wastewater of anaerobic effluent is degraded by the action of multiple contact oxidation ponds, so that the COD concentration of effluent is reduced to less than 500mg/L.
In short, the treatment of paint production wastewater is a complex process, which requires comprehensive consideration of multiple treatment methods to achieve efficient and environmentally friendly treatment results. Like, follow, collect, Liyuan Environmental Protection will continue to provide you with the latest knowledge of wastewater treatment.