Cleaning of drains
State Ecology today, tounfortunately, leaves much to be desired. This is the result of disorderly use of natural resources. Water consumption is constantly growing humanity, and clean water supplies naturally decrease with each passing year. The use of detergents and various household chemicals greatly pollute sewage modern cities, which greatly complicates the cleaning of drains. Sewage water contains a lot of different pollutants, from mechanical components to complex chemical compounds, so the waste water treatment - a complex and multi-layered.
- wastewater treatment methods.
- Stages of wastewater treatment in sewage treatment plants.
- Equipment for the mechanical purification.
- Facilities for biological treatment.
All water treatment methods can be dividedon the destructive and recuperation. The result will be a destructive treatment methods decomposition of complex compounds to simple contaminants, they will be output in the form of water-gas, will fall either in precipitate or remain dissolved in the water, but neutralized. The result of recuperation treatment methods will extract from the wastewater of all valuable materials for further processing.
Methods for wastewater treatment
- Disinfection of wastewater;
- Thermal recycling.
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 means zhirolovok and benzomaslouloviteley. The improved mechanical cleaning method - membrane - is used in conjunction with traditional methods and allows for a more thorough cleaning. Mechanical sewage treatment is a preparation for biological treatment, and allows you to remove from household waste and 70% of impurities, and from 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, the effluent are released from organic nitrogen and phosphorus. Biological treatment is aerobic and anaerobic.
- Aerobic wastewater treatment is carried out athelp aerobic bacteria for the life which need the oxygen. With this cleaning used biofilters and aeration activated sludge. Aeration tanks are highly efficient and more effective than biofilters for the treatment of wastewater. In the aeration tanks made aeration of water and its deep biological treatment. Moreover, the result is the activated sludge, which is a good fertilizer.
- Anaerobic wastewater treatment is carried out withoutoxygen. 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, as it does not need aeration.
3. Physico-chemical method involves electrolysis, coagulation and precipitation of phosphorus, iron and aluminum salts.
4. Disinfection occurs wastewater with ultraviolet irradiation or ozonization chlorine treatment. It is used for disinfection before discharge into water bodies.
- Disinfection with UV radiation - morea safe and effective method compared to chlorination, since it 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 activeChlorine is detrimental impact on microorganisms. A significant drawback of this method is the formation of chlorinated toxins and carcinogens.
- Ozonation - disinfecting wastewater with ozone. Ozone - a gas consisting of three-atom oxygen molecules, a strong oxidizing agent that kills bacteria. It is quite expensive disinfection method in which the emission of harmful substances, aldehydes and ketones.
5. The thermal process used to recycle waste water when other methods are not effective. The gist of it is that the atomized waste water is disinfected in the plume of fuel burned.
On modern waste water treatment plants are phased cleaning while sequentially apply the techniques described above.
Stages of wastewater treatment in sewage treatment plants
- Preliminary mechanical cleaning;
- biological treatment;
Equipment for the mechanical purification
- grille - bars of a rectangular shape with a crevice to 16mm;
- sand traps (set for cleaning a 100m3 per day);
- reclaimers (installed if needed composition averaging);
- septic tanks (are horizontal, vertical, radial, Bunk);
- septic tank (used for wastewater treatment, bound for the filter trenches, wells and underground filtration field);
- hydrocyclones (need for wastewater treatment from suspended solids);
- Centrifuge (emit fine material when you can not use reagents);
- flotation units (used to extract oil, grease, petroleum products);
- degasser (remove dissolved gases in water).
Facilities for biological treatment
- preaeratory and biokoagulyatory (reduce the concentration of heavy metals and other pollutants);
- biological filters;
- aeration tanks, cesspool emptier, metatenki (facilities for cleaning aerobic and anaerobic method);
- secondary sedimentation, filtration fields and desilters (designed for full biological wastewater treatment);
- biological ponds (intended for deep cleaning of wastewater containing a lot of organic matter).
At the post-treatment of wastewater used theirneutralization and filtration. Disinfection or decontamination is performed with chlorine (chlorine is necessary to farm) or by electrolysis (necessary construction of electrolysis plants).
As you can see, wastewater treatment - the processmulti-stage, requiring a scientific approach and compliance with all rules and health standards. The above methods of sewage treatment applied in the complex. The choice of method depends on the nature of the wastewater and their quantity, type and concentration of pollutants.