The higher the level of development of the civilization, the greater the amount of waste it produces.Today, the most urgent issues of our time are as follows: "What to do with sewage? How are they clean? What is the treatment of sewage and waste effluent?"
Clean water flowing into the sewers - a process whose goal is the destruction or degradation of harmful substances and impurities present in these waters.Some experts believe that this process is a single, but consists of several stages.Other each step of purification was isolated as an independent method.In any case, the rectification of sewage used a variety of methods of wastewater treatment.They are rectified by means of:
- reagents, chemicals;
- filtration and sedimentation;
- electrolysis;
- oxidation, and other physical and chemical transformations;
- bacteria, microbes, other micro-organisms;
- all ways at once (in stages).
choice of a particular method depends on the ultimate goal of
Mechanical methods of wastewater treatment
basic techniques - filtration and sedimentation.Most large dirt is removed by gratings cope with finer sieve.
The filtered water passes through a sand trap, a special membrane and a septic tank.
contamination from the surface is removed by oil, oil or benzinolovushek.Settling with the use of filters allows for a 75-95% clean impurities from the water, part of which is suitable for processing.
Chemical methods of wastewater treatment
So called purification process in which the waste water to make the reagents which decompose impurities.From 25% soluble and 75% insoluble contamination is eliminated by this method.
Physico-chemical methods of sewage treatment
With such cleaning frequently used:
- Coagulation - "bonding" of fine particles in large formations.
- Oxidation - a reaction in which pollution "burned" by the action of the reagents.
- Sorption - absorption reagent contaminants from wastewater.
- Extraction - extraction of water dry substances.
Application sorption, coagulation, extraction and other techniques help to remove fine particulate, inorganic contaminants or destroy organic contaminants are poorly oxidized.
Biological methods of wastewater treatment
The essence of such a reception that uses the natural processes that result in self-purification of water bodies.For the rectification of waste water is often used:
- Biofilters - devices through which filtered water.From conventional biofilters are characterized in that their surfaces are cultured anaerobes oxidizing contamination.
- aeration tank - tank for water, built of reinforced concrete.Here microorganisms amoeba and ciliates in their lifetime creates sludge, by which is cleaned.Mushrooming in the mud amoebae, rotifers and other entities contribute to the continuous rejuvenation of the muddy substrate.Biological processes are developing rapidly, because the body is provided with a constant supply of food - waste water.
- Biological ponds - man-made structures to defend water, working on the principle of natural self-cleaning.The process involves all the organisms living in a pond.
Electrolytic methods of wastewater treatment
most cost-effective they are, where waste water contaminated with lots of metallic impurities: in the paint, copper industry, etc.The cleaning process is carried out in special containers.
