Typical industrial wastewater treatment methods outlined

In recent years, there have been new methods and techniques for the treatment of industrial waste water, but each has advantages and disadvantages. Biological oxidation of pure water contains a certain amount of refractory organics, COD value is high, you can not fully meet the emission standards. Although adsorption can better remove COD, but there adsorbent regeneration and secondary pollution. Although catalytic oxidation can degrade poorly biodegradable organic matter, but the actual industrial applications exist the problem of higher operating costs.
Especially now that the pollutants in industrial wastewater are diverse, often using a process that can not remove all contaminants in wastewater depleted. Using materialized industrial wastewater treatment process will be very difficult to discharge standards, but higher operating costs; industrial wastewater containing more refractory organics, poor biodegradability, and industrial wastewater effluent water quantity and quality changes, so you can directly deal with biochemical methods industrial waste water is not very satisfactory.
For industrial wastewater treatment characteristics, we believe that its treatment should be based on actual wastewater quality appropriate pretreatment methods, such as flocculation, electrolysis, electrolysis, adsorption, photocatalytic oxidation process, destroy refractory organics in wastewater, wastewater improvements biodegradability; further combined with biochemical methods, such as SBR, contact with oxygen Industrial Arts, A / O process, etc., in-depth treatment of industrial wastewater.
Typical industrial wastewater treatment methods outlined
Phenolic wastewater Molybdenum tube from the coking plant, gas, petrochemical plants, insulation material factory and other industrial sectors as well as petroleum cracking ethylene, synthetic phenol, polyamide fibers, synthetic dyes, organic pesticides and phenolic resin production process. Main phenolic wastewater containing phenolic compounds such as phenol, cresol, xylenol and nitro-p-cresol. Phenolic compound is a protoplasm poison, make protein coagulation. Concentration of phenol in water up to 0.1 a 0.2mg / L, the fish odor that is, can not eat; increased concentration of 1mg / L, may affect fish spawning, phenol 5-10mg / L, will be a lot of fish deaths. Phenol in drinking water can affect human health, even if the concentration of phenol in water only 0.002mg / L, with the stench of chlorine disinfection will produce PCP. Typically the concentration of 1000mg / L of phenol wastewater. Called high concentration wastewater, such waste shall be recovered phenol, and then processed. Mass concentration is less than 1000mg / L of wastewater, known as low density phenolic wastewater. Typically this type of waste recycled, the phenol concentration and recovery post-processing. Phenol recovery methods are solvent extraction, steam stripping, adsorption, closed loop method. Phenol concentration in the 300mg / L less water available biological oxidation, chemical oxidation, chemical oxidation methods such as physical discharged after treatment or recycling.
Mercury-containing waste
Mercury-containing waste water mainly from non-ferrous metal smelters, chemical plants, pesticide plants, paper mills, dye and thermal Instrument Factory and so on. Removal from wastewater methods of inorganic mercury sulfide precipitation, chemical coagulation, activated carbon adsorption cowardly, metal reduction, ion exchange method and molybdenum plating method. Generally alkaline wastewater containing mercury commonly used chemical coagulation or sulfide precipitation method. Available acidic wastewater containing mercury metal reduction method. Low concentrations of mercury-containing waste water available activated carbon adsorption, chemical coagulation or activated sludge process, organic mercury waste are difficult to handle, usually the first organic mercury is oxidized to inorganic mercury, and then processed.
A variety of toxic mercury compounds vary greatly. Elemental mercury basic nontoxic; inorganic mercury in the mercuric chloride is highly toxic substances, organic mercury in the phenyl mercury decompose faster, little toxicity; methylmercury is easily absorbed into the body, not easily degradable, excretion is very slow, especially it is easy to accumulate in the brain. Toxic, water Minamata disease is caused by the methylmercury poisoning.
Oily wastewater
Oily waste water mainly from petroleum, petrochemical, steel, coke, gas stations, machining and other industrial sectors. Oil in water pollutants, in addition to the relative density of heavy tar is 1.1 or more, the rest of the relative density of less than 1. Oil substances in the wastewater usually exist in three states. (1) floating oil droplet particle size greater than 100μm, easily separated from the waste water. (2) dispersed oil droplet particle size ranging from between 10 to 100μm, Ken floating in water. (3) emulsified oil droplets size less than 10μm, easily separated from the wastewater. Due to different industrial sectors effluents oil concentration differences, such as the waste water generated in the refining process, oil is about 150 a 1000mg / L, coking wastewater tar content of about 500 a 800mg / L, gas station discharged wastewater tar content of up to 2000 a 3000mg / L. Therefore, the oily wastewater treatment should first use grease traps, recycle the oil slick or heavy oil, processing efficiency of 60% to 80% of the oil out of the water about 100 a 200mg / L; wastewater emulsified oil and dispersed oil is more difficult to processing, it should prevent or reduce emulsification. One way of reducing the production process of attention waste oil emulsion; Secondly, in the process is to minimize the number of the pump to enhance the water, so as to increase the degree of emulsification. Treatment usually flotation method and breaking laws.