Before granulation of waste plastics plastic sheets, plastic bags and plastic bottles for cleaning sewage mostly suspended particulate pollutants, less soluble material, cleaning plastics requiring a great deal of water, sewage produced are the following features:

Organic pollution: waste plastic packaging over the main contact or food, feed and beverage.
PH value of pollution: waste plastic crushing washing process mainly added alkaline substances.
Suspended solids pollution: waste plastic agricultural film, packaging films over the main contact or synthetic soil dust, waste plastic particles.
Oil pollution: waste plastic PET bottles main contact or glossed over oil substances.

Different varieties and sources of waste plastics, pollution is not the same, are the following:
Suspended solids pollution: waste plastic packaging over the main contact or cotton, chemical fiber, quartz sand, cement, calcium carbonate.
Organic pollution: waste plastic packaging over the main contact or food, feed and beverage.
Oil pollution: waste plastic packaging main contact or too fat substances.
Dissolved pollution: waste plastic packaging over the main contact or sodium chloride, sodium carbonate and the like.
Color pollution: waste plastic packaging over the main contact or dye pigments.
PH value of pollution: waste plastic packaging main contact or too strong acids and strong alkaline substances.
Microbial contamination: mainly from waste plastic disposable medical equipment.
Toxic pollution: waste plastic main contact or packaging toxic and hazardous materials.

For washing, crushing process is only suspended solids in water have higher requirements. Coagulation treatment process can be used to remove most of the suspended solids in wastewater, sewage and then go back to the production process used to achieve the purpose of reducing the amount of sewage discharge. Efflux can be mixed with sewage effluent to improve their biodegradability, then by biological treatment after discharge.

Using flotation -A / O biochemistry - Dosing precipitation combination treatment process of waste plastic washing water

Jiangmou Chemical Fiber Factory is an import plastic scrap and waste production of polyester staple fiber business, the main raw material used in polyethylene terephthalate (alcohol) esters and polypropylene. Using the waste plastic recycling process hot caustic process, the caustic water of about 500 m3 / day, due to the long cycle caustic water use, resulting in an accumulation of organic matter concentration, although 80 percent of water production and reuse, but still some high concentration caustic wastewater efflux. In order to understand the effluent quality characteristics to determine a reasonable treatment process applies, under laboratory conditions effluent sampling carried out chemical analysis, biochemical tests and drug treatment water samples measured after adding a small sample, the process to select a major consideration consider caustic water recycling in the production process, we determined the overall physical and chemical sewage treatment and reuse, and then by biological treatment portion of the discharge design ideas, can save a total investment of the project, but also reduce the biochemical system load. Regular emissions alkali cooking liquid through the addition of acid neutralization, and directly through the sludge drying system processing.

Water analysis showed caustic wastewater complex components, high concentration (cumulative factor), is a refractory organics, even after physico-chemical treatment, is still very low. In the long residence time of pure aerobic treatment conditions, its molecular structure is difficult to be destroyed, biodegradation half-life is very long, as applied to the project, the investment is large, uneconomical.

Refractory organics refers to the microbial degradation can not, under any circumstances or conditions can not be fast enough to prevent it from accumulating in the degradation of the environment. The reason there are a variety of non-degradable organic matter, but can be broadly divided into two categories: micro-organisms are toxic; stable chemical structure. For caustic wastewater component of plastic waste generated in the process of complex features, the use of physical and chemical means to alter the biological pretreatment of refractory organic compounds structure, eliminate or reduce their toxicity, biodegradability increase; the same design line and biodegradable develop suitable drug resistant but can degrade microbial improve biological treatment processes and equipment, which is the key to the success of plastic waste caustic wastewater treatment. With training, modification, adjustment, and other means of variation and inoculation training system can break down biodegradable organic matter microbial activated sludge process is to improve one important way, domesticated activated sludge can resist the effect of high concentrations of pollutants effect.

Initial commissioning process, the selection of coking natural anaerobic wastewater treatment tanks were inoculated group active anaerobic training, control the amount of water, increasing the stage regularly borrow biological sample observation phase, to keep abreast of the growth of bacteria, and adjust the amount of water and aeration. The whole project is running, good or bad is the key to dealing with the effect of flotation physicochemical treatment processes for proper operation; sewage removal rely mainly on aerobic biological treatment; Dosing Coagulation physico-chemical treatment to ensure that the effluent standards. Flotation -A / O biochemistry - Dosing precipitation combination treatment process of waste plastics caustic wastewater project more than a year after the actual operation, the entire processing system is stable, the treatment effect is good, the water quality indicators meet the design requirements and better the emission standards.