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Please use the already defined membrane systems nor filtration, the remaining options for wastewater treatment are relatively short. Within the so-called intensive technologies for water treatment, it is possible to mention the membrane bioreactors (BRM), a sequential batch reactors and also the bio. Now, briefly explain what constitutes each of these technologies.

Sequential Batch Reactors
Work through the activated sludge. In this system, both the functions of aeration and sedimentation, such as decanting, is made in the same reactor. It is usually used at least two tanks for the reaction, thus ensuring a continuous waste water treatment and efficiently. These systems do not occupy large areas and have very competitive costs. Generators are high quality effluents and also easily treated for regeneration.

Automatic softeners, are used to remove hardness in water treatment. They are used for domestic sewage, treated wastewater or industrial wastewater.

Then explain the basic principles of this system:
Some insoluble compounds have the ability to set alkali ions (these are: Ca, Mg, etc.), changing by sodium ions. Previously they were called zeolicos. When you run water through a bed of cation exchangers such sodium, alkaline earth salts found in the water become sodium salts.

If we want to make evaluative analysis on different kinds of waste water treatment, is critical to bear in mind and learn about different types of wastewater that exist. Also, it is necessary to have information about contaminants, such as what these pollutants, which are common, what negative consequences can generate discharges, how to perform quality checks, etc..

Let's start by listing the major types of wastewater. The classification is made regarding the origin of water, because it is what determines the composition of the substance.

The seawater treatment performed by a desalination plant consists of five basic steps:
1. The first stage of treatment to desalinate water, consists of the collection and pre-treatment. At the bottom of the sea, collecting ducts are one of hundreds of meters long. These are responsible for capturing the salty water and take it to the pre-treatment section. In this area, we make the separation of suspended solids and sodium hypochlorite is added to strip the water of bacteria and other microorganisms.
2. Then he continues the filtering stage. This is done using sand filters and coagulants such as ferric chloride. These are responsible for sifting the smaller particles remaining dissolved in the aqueous solution.

There are several methods for a proper disinfection of wastewater. It's good to know the characteristics of each of these technologies in order to choose the one best suited to treatment of water we want to perform.

The Ozonation
One option for disinfection is ozonation. Ozone, may spread in the air of wastewater directly reacting with organic matter. As a result, generated a series of chemical reactions involving radicals. Some of these reactions, have the ultimate effect of water disinfection. Generally, ozonation is effective in removing bacteria and virus groups. It also includes a number of advantages: eliminates odors, does not produce other dissolved solids, and has the ability to increase the oxygenation of the effluent without affecting its pH. The technique is performed in situ, using commercial kits. When the content of organic matter in water is very high, it takes comparatively high ozone dose to achieve a successful disinfection.

While many times have you wanted to label as a process of osmosis filtration on a molecular scale is easy to understand and realize that reverse osmosis is a process clearly differentiated from the micro filtration or filtration.

There are three aspects which indicate clearly that this difference:
1. In the process of filtering the entire flow passes through the separator element. This only prevents the passage of solid particles of a predetermined size.
2. By contrast, reverse osmosis, only a portion of the feed rate through the membrane and constitutes the product. The remaining flow is discharged without passing through the membrane and becomes the rejection.
3. In reverse osmosis, never separated material accumulates on the surface of the membrane, as occurs in other processes, as is the rejection which is responsible for the drag of the material.
4. While the osmosis seawater flow is parallel to the membrane, filtration is perpendicular.

You can remove suspended solids larger than to 0.1 - 1.0 m. It is particularly effective at removing large pathogens such as Giardia or Cryptosporidium. Ultrafiltration is common to use in cases where the concentration of STD is not a problem. This is because the membrane pores are too large to filter out particles as small. Generally used as a pretreatment for systems using much more sensitive membranes, such as reverse osmosis or nanofiltration.

Ultrafiltration It basically used to remove most of the colloidal particles and some major pollutants dissolved (0.01  m). It is useful when you must eliminate most of the colloidal particles (also including pathogens). This system, like microfiltration, has the ability to kill bacteria and viruses and is often used as a pretreatment for other systems. Because colloids are removed, the water, once treated has a negligible turbidity.

When choosing regeneration technologies for advanced treatment of wastewater, is often to prefer those that demand too much energy. This explains and justifies why the waste water often is often used for irrigation or other purposes which are relatively few "noble." Some membrane technologies for the treatment of salt water, are often used on islands or in places where there are too many resources, such as in coastal areas with its existing resources almost depleted. Also used in some special occasions where not issued the corresponding operating premises for some uses luxuries. Another example of its use are the golf courses and farms where the crop allows the necessary investment and continued maintenance of the plants.

In this connection, are emerging in several areas with safe water, a lot of mini-desalination plants. This phenomenon brings with it a disadvantage. It creates a serious problem, because pickles are removed abruptly. If these processes are launched, later reuse could be considered absolutely mandatory from the perspective of environmental sustainability.

As is known, the desalination of seawater is one of the most viable alternatives for our future. However, this process presents considerable disadvantages such as high costs and high energy. To overcome this last drawback, desalination and water treatment through the use of wind power presents itself as an attractive option for our future.

The wind desalination, is a water purifying system that works by reverse osmosis. What is new is that it is not necessary to supply electricity for the system to do its work. It is capable of generating its own power, using air movement. This class of systems routed through the action of a wind mill. Thus, whenever the wind blows, the system will be able to treat drinking water.

One alternative for treating wastewater is the use of biological systems. Thus it is possible to decrease the organic content of water, as well as remove pathogens and parasites. The biological water treatment can be achieved through aerobic and anaerobic processes.
Here are some:
Sludge ponds:
In this case, mechanisms are used entering air into the tanks. On contact with air, the organisms react to generate flocs, settles them in passing the so-called clarification tanks. To treat wastewater through the biological system, you need: an aeration tank and a clarification by the sludge being passed repeatedly.

The main objective of activated sludge system is the oxidation of biodegradable matter in the aeration tank, and flocculation, which enables the separation of biomass from treated effluent. Removal can be achieved up to 90% of the organic load. However, there are some drawbacks: it requires expensive facilities and investment in electromechanical equipment with a high energy cost. It also produces a significant amount of sludge that later require further treatment by anaerobic reactors and / or landfill disposal installed correctly.