environmental condition today, unfortunately, leaves much to be desired.This is the result of disorderly use of natural resources.The consumption of water is growing humanity, and reserves of fresh water in nature every year decrease.Using different detergents and household chemicals greatly pollute sewage modern cities, which greatly complicates the treatment of wastewater.The waste water contains a lot of different pollutants, from mechanical components to complex chemical compounds, so the waste water treatment - a complex and multi-layered.
All methods of waste water treatment can be divided into destructive and recuperative.The result of destructive methods of purification will be difficult decomposition of polluting compounds into simple, they will be output from the water in the form of gases or will fall in the precipitate
methods of wastewater treatment ↑
- Mechanical Biological
- wastewater disinfection
- thermal utilization
1. The mechanical method is the easiest.Mechanical cleaning of waste water insoluble components are removed polluting the water, both solid and surface greasy dirt.Wastewater first pass through the lattice, and then through the sieve sumps.Smaller components are deposited sand traps.Wastewater from oil by using zhirolovok and benzomaslouloviteley.An improved method for mechanical treatment - membrane - used in conjunction with traditional methods and allows a more thorough cleaning.Mechanical treatment of wastewater is a preparation for biological treatment, and allows you to remove from household waste and 70% of impurities, and from the industry - up to 95%.
2. Biological wastewater treatment is due to the activity of microorganisms capable of oxidizing organic matter.The basis of this method is the natural purification of rivers and reservoirs microflora inhabiting them.Thus, waste water are released from organic nitrogen and phosphorus.Biological treatment is aerobic and anaerobic.
- Aerobic wastewater treatment is carried out with the help of aerobic bacteria, which is needed for the life of oxygen.When you apply a cleaning biofilters and aeration activated sludge.Aeration tanks have a high degree of purification and more effective than biofilters for waste water treatment.Aeration in the aeration tank is made of water and its deep biological treatment.Moreover, the result is the activated sludge, which is a fertilizer.
- anaerobic wastewater treatment is carried out without oxygen.Under the influence of anaerobic bacterial fermentation process takes place and the conversion of organics to methane and carbon dioxide.This method is used metatenki.Anaerobic treatment requires lower costs than aerobic exercise, as this does not need aeration.
3. Physico-chemical methods include electrolysis, coagulation and precipitation of phosphorus, iron and aluminum salts.4. Disinfection
wastewater occurs by ultraviolet irradiation, treatment with chlorine or ozone treatment.It is used for disinfection prior to discharge into water bodies.
- Disinfection UV radiation - a more efficient and secure method compared to chlorination, as this does not form harmful toxic substances.Ultraviolet radiation detrimental effect on virtually all microorganisms and effectively kills cholera, dysentery, typhoid, hepatitis, polio and other diseases.Chlorination
- based on the ability of active chlorine detrimental impact on microorganisms.A significant disadvantage of this method is the formation of chlorinated toxins and carcinogens.
- Ozonation - Ozone disinfection of wastewater.Ozone - a gas consisting of three-atom oxygen molecules, a strong oxidizing agent that kills bacteria.It's pretty expensive disinfection method in which there is an allocation of harmful substances: aldehydes and ketones.
5. Heat recycling used to process wastewater, when other methods are ineffective.The gist of it is that the atomized waste water is disinfected in the plume of fuel burned.
In modern waste water treatment plants are phased cleanup, while consistently apply the methods described above.
Stages of wastewater at treatment plants ↑
- preliminary mechanical cleaning;
- biological treatment;
equipment for the mechanical purification ↑
- lattice - rectangular bars with Prozorov to 16mm;
- sand traps (set for cleaning a 100m3 per day);
- reclaimers (set if you want to average composition);
- septic tanks (there are horizontal, vertical, radial, Bunk);
- septic tank (used for wastewater treatment, traveling to filter trenches, wells and underground filtration field);
- hydrocyclones (needed for wastewater treatment from suspended solids);
- centrifuge (emit fine material when you can not use reagents);
- flotation units (used to separate oil, grease, oil);
- degasser (remove dissolved gases in the water).
Facilities for biological treatment ↑
- preaeratory and biokoagulyatory (reduce the concentration of heavy metals and other pollutants);
- biological filters;
- aeration, ilososy, metatenki (facilities for aerobic and anaerobic treatment method);
- secondary sedimentation, and filtration fields desilters (designed for full biological wastewater treatment);
- biological ponds (intended for deep cleaning of wastewater containing a lot of organic matter).
With advanced treatment of wastewater is used to neutralize and filter.Disinfection and decontamination is performed with chlorine (chlorine necessary facilities) or by electrolysis (necessary construction of electrolysis plants).
wishing to get acquainted with the device and the principle of the biological treatment plant will view the video.
As you can see, wastewater treatment - a multi-step process that requires a scientific approach and compliance with all rules and sanitary standards.The above methods for purifying wastewater are used in combination.The choice of method depends on the nature of the wastewater and their quantity, type and concentration of pollutants.