Wastewater Treatment

2019-07-04 11:49:22
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 Industrial waste water treatment: ozond system can be almost used in all kinds of wastewater. The process of wastewater oxidation depends on the types of wastewater from different industries

Treatment process categories: chemical process, chemical/biological process and chemical/biological/physical process.
Ozone application: indoor pre-treatment for cycling water, water to be indirectly discharged to public water facilities, or post treatment for water to be directly discharged to river and bay.
Compound removal: oxidation of harmful or colored substance, reduce comprehensive parameters (COD or DOC). Normally, the process combines ozone oxidation and biodegradation, namely O3-biological treatment-O3, to lower the ozone dosage and operation cost.

Disinfection

Before discharging to the receiving water, wastewater requires disinfection treatment to meet the water quality standard. For example, if the waterwater is to be used for irrigation, it will  require disinfection with ozone dosage even more then the one in drinking water, The most common disinfectant is chlorine disinfection can cause halide, especially the trihalomethanes (THMS). Because of the undesired by product from chlorine, the ozone application is becoming more and more popular. When making the chemical disinfection design, the CT concept (concentration of free disinfectant: C multiply contact time: T) in Chick-Watson law is often used, Substantial past and recent researches have proved that molecular ozone is very effective disinfectant, having better effect than the free chlorine and chlorine dioxide, and it will be widely used in future.

Inorganic compound oxidation

Ozone can be used to oxide inornanic compound, destroying the harmful substance in wastewater. This is mainly limited to cyanide removal, Cyanide is often used in metal processing and electrolytic treatment. It can be in the form of free state CN-, but most of the time, it combines iron, copper or chromium. Ozone has fasr traction with cyanide ion when cyanide ion concentration is higher than 5mg/L. Ozone can be used in nitrite (NO2-) and sulfide (H2S2-) oxidation, as they also have quick reaction with ozone

Organic cpmpound oxidation
 
  • Transformation of poisonous compound
  • Oxidation of the non-biodegradable dissolved oranic carb on (DOC), improving the effect of the following biodegradation process.
  • Color reomoval
Sikilar to drinking water, it is difficult to use economic method to mineralize the wastewater, and it is advised to use ozone for oxidattion and combine with other processing, The effect of the treatment is measured by the total DOC removal. The main pollutants of the trash penetrating fluid, textile, pharmaceutical and chemical in dustry wastewater are dissicult to degarde. Hence, ozone system has been used for oxidation in this field. The pollutants can be categorized as below:
 
  • Humus from trash penetrating fluid (in brown or yellow) and absorbable organic halide (AOX)
  • Aromatic compounds from textile wastewater which are oftern combined with metal ions: Cu, Ni, Zn, Cr.
  • Pharmaceutical and chemical industries ofern generate poisonous substance (for example: pesticide)
  • Surfactants (surface active agent) from osmetic or other industries
  • Effluent in Pulp and papermaking