KUSADASI WATER TREATMENT COMPANIES

Reverse osmosis technology is the most sensitive membrane filtration technology known. It is a system where high pressure is applied to remove or recover dissolved inorganic and organic materials from water, which are usually used in industrial wastewater treatment, in order to ensure that wastewater can be reused.

The Reverse Osmosis (CTR) technique has been used in the world since the 1970s.Since it was very expensive at first, this technique, which was used only to obtain drinking water from sea water on ships, has become cheaper over time and has gone under the counter in our homes. With the developing membrane production techniques, the cost of water produced with CTR has also decreased a lot.

During the reverse osmosis process, pressure is needed and this pressure is provided by means of a pump. Information such as the number of membranes, the type of membrane, the pressure to be applied, the recovery rate that the reverse osmosis unit will contain can only be obtained by analyzing the raw water character very well.

In soft drinks, water makes up 80-90% of the product and the quality of the water directly affects the end product. In this context, the raw water coming to the facility should be prepared for quality water that can be used in production. Water preparation has two purposes. The first is to bring alkalinity to acceptable levels. Alkalinity is the ability of water to neutralize acid, expressed in terms of mg/liter CACO3. The other is the reduction of the total amount of dissolved matter (TMM) (mg/liter), especially chloride and sulfate anions. Apart from these, it is necessary to remove all kinds of solid substances from the water with dissolved organic substances. In the case of alkalinity and other inorganic substances, water can be prepared simply by reverse washable layer sand filter followed by chlorination/ozonation. Although this process filters the water to the order of 5-10 microns, the sand filter, the microorganisms that form in it over time and the excessive amount of water is spent during backwashing are the negative aspects.

The use of membranes for filtration has become widespread in recent years. They are polymeric (plastic) or ceramic with small pores on them. A large number of solids as well as dissolved inorganic and organic substances

section. Basically, membrane filtration is listed as microfiltration (MF), ultra filtration (NF), nano filtration (NF) and reverse osmosis depending on the pressure increase applied.

02. Technical Terms Used in Reverse Osmosis System

Ion: A natural mineral that has received or given off electrons while dissolving in water. For example, when table salt (NaCl) is dissolved in water, ions (Na +) and (Cl -) are formed.

Demineralized = Deionized: Separating the minerals and ions contained in water from water. "Deionized water" or "Demineralized water" is pure water free from minerals.

Regeneration: To bring the ion exchange resins to their initial state by performing a chemical process, to "renew".

Conductivity: It is the ability of water to conduct electricity. The commonly used unit of measurement is "microsiemens/cm" (S/cm) and micromho. As the amount of dissolved minerals in water increases, the conductivity of water increases. For example: if there is only 100 mg/l of NaCl salt in water and there are no other dissolved substances, the conductivity of this water is 212 microsiemens/cm.

Total Amount of Dissolved Substances: It is the sum of the weights of minerals dissolved in water, measured in mg/liter. As the amount of dissolved matter in water increases, the conductivity of water increases.

Total Hardness: It is the sum of Calcium (Ca) and Magnesium (Mg) compounds dissolved in water. Hardness is expressed in three different units in our country: mg/l in CaCO3 (calcium carbonate); French hardness (= 10 mg/l CaCO3); German Hardness (= 17,9 mg/lt CaCO3).

Total Alkalinity: It is the ability of water to neutralize acid. It is the sum of CO3, HCO3, and OH ions in water. Total Alkalinity is expressed in mg/l CaCO3.

pH: Refers to the acidity of water. The pH value is between 0 and 14. pH=7 is the numerical value of a neutral water. If the pH is between 0 and 6.5, the water is considered "acidic", and if the pH value is between 8 and 14, the water is considered "basic" or "alkaline".

Dissolved Carbon Dioxide: Determines the amount of CO2 gas dissolved in water in mg/lt.

Membrane: The "synthetic membrane", which is called "membrane" in living things in nature, which performs its function in the Reverse Osmosis system of the semi-permeable two-dimensional biological organ. The other name of the Reverse Osmosis technique in the literature is "Membrane Technique".

03. Reasons Supporting the Development of the Reverse Osmosis Device

New inventions are made and patents are obtained every day. But not all of these new inventions hold on to the market. The most important reasons for the rapid development and retention of water purification technique with reverse osmosis in the world market are:

"Water Quality" gaining importance in the industry; The fact that enriched people want to live and holiday on the seashores that do not have enough water by pushing the natural conditions, and that cities and hotels located on the seashores and have limited "Fresh Water" resources are installing CTR systems to produce drinking and potable water from sea water. The number of these systems is increasing.

03.01. Improving Water Quality for the Needs of Industry

The "Ion Exchange Resin Technique" was developed many years ago to improve the chemical quality of water, that is, to remove minerals dissolved in water from water. Thanks to this technique, not only industry, but also the development of old ships powered by high-pressure steam boilers was achieved. Today, Reverse osmosis (TO) technique is preferred instead of resinous ion exchanger in many exercises, because CTR is more economical and more environmentally friendly compared to resinous systems.

Working Principle of Ion Exchange Resins :

Today, the devices in every industrial facility, which we call "Water Softening Device", are also "Ion Exchangers". These devices also contain Ion Exchange Resin. These resins, which are regenerated with Table Salt, i.e. "NaCl", take the Calcium (Ca) and Magnesium (Mg) ions in the water, which are called hardness, from the water, and instead give the water the Sodium (Na) ion in the NaCl salt. As a result, the hardness in the water is removed, but the sodium content of the water is increased, that is, the water does not become purified, the mineral amount of the water does not change, and the conductivity of the water does not change, or even increases slightly.

It is possible to demineralize water with devices called "Demineralize" or "Deionize" devices, which are similar to water softening devices in their external appearance, but have other resins inside. In this technique, two very different types of "ion exchanger" resins are used. With "Cationic Resin", (+) charged ions in water are taken and replaced with (H+) ions contained in Acid (HCl). With "Anionic Resin", the charged ions in the water (-) are taken and replaced with the (OH-) ion contained in the Caustic (NaOH). At the end of this process, since the (H+) and (OH-) ions charged into the water combine among themselves to form the H2O, that is, the SU molecule, the water is free of minerals and becomes pure.

Although systems powered by Ion Exchange Resins are still in use, there are some operational issues:

Due to the long regeneration time, it is necessary to use two of each resin tank (redundantly) to obtain pure water continuously. In addition, large volume tanks are also included in the system for the acid and caustic required during the regeneration of these resins. In addition to these tanks, a large volume tank is required for the collection of waste water released during regeneration. After the pH neutralization of the wastewater collected in this tank is carried out in this tank, the waters are discharged. For these reasons, the Resinous Demineralizing system is very bulky and takes up a very large space. For example, because there is a shortage of space on ships, shipbuilders prefer less space-taking CTR systems instead of a resinous system.

After each regeneration of resins, the quality of production water may deteriorate for a certain period of time. This is a weakness of resinous systems.

A large amount of Acid and Caustic is used for the regeneration of resins. The biggest business problem is experienced with these chemicals. Because these two chemicals are very harmful for humans and the environment. The purchase of these two chemicals, the control of their quality when they are purchased, their storage, the risk of skin burns caused by splashing on the operators (my hand was also burned with acid during the control of a dosing pump) brings with it many operational problems.

Environmental problem: during the regeneration of resins comes out acidic and caustic waters with tons. It is not possible to send these waters not only to the canal, not even to the waste treatment plant. This water must first be collected in a pH balancing tank, where pH neutralization is carried out, and then sent to the waste treatment plant. This is a reason that makes the system cumbersome, takes up a lot of space and increases the cost of producing pure water. In addition, dosing systems and automation are involved in the operation of the pH neutralization tank, which are also at risk of skin burn by the operator during their maintenance.

In countries where Labor Laws and Health rules work well, the insurance risks of workplaces where acid and caustic are used are high and such workplaces pay more insurance premiums to insurance companies.

Due to the above-mentioned operating problems, after the invention of the reverse osmosis (CTR) device, it was preferred in industrial countries, especially in A.B.D. Of course, the prices of TO devices were high when they were first invented. Therefore, the above business issues that seemed negative today were considered "manageable" issues when faced with the high price of CTR. However, TO devices have become cheaper since 1990, and with the developing membrane techniques, the cost of water produced with CTR has decreased a lot (the cost of one ton of water obtained by TO from a well water with a maximum of 2000 mg/liter of dissolved minerals is on the order of 0.20 – 0.30 dollars). Today's prices and operating costs of CTR devices are very low, and therefore CTR is preferred over resinous systems with operating risks and operating difficulties.

04. Reverse Osmosis System

Types of reverse osmosis systems as domestic, industrial and under-bench

There is.

Reverse Osmosis Systems Used at Low Flow Rates

RO models at low flow rates for homes or businesses with low water needs

they are suitable. These RO systems have a treatment capacity from 40L/h to 500 L/h.

Industrial Reverse Osmosis Systems

RO systems at high flow rates are produced for high-capacity enterprises, hotels and all types of organizations with high water needs. These RO systems have treatment capacities that connect from 850 L/h and can be produced up to the desired flow rates.

Under-Counter Reverse Osmosis Systems

04.01. Working Principle of Reverse Osmosis System

The working principle of the reverse osmosis process is thanks to the membranes located on the device. Water is forced to pass through the pores located on the membranes, under high pressure. During this process, water molecules and some inorganic molecules can pass through these pores, while most of the substances in the water cannot pass through these pores and are excreted as concentrated water. This process allows to obtain much better water quality at the desired capacity compared to other filtration systems. With the developing technology, it has become possible to produce fully automatic reverse osmosis devices and reverse osmosis devices have risen to the top in professional treatment with the desired flow rate of high quality water.

It is essential to store the water at the exit of reverse osmosis as the flow rate will be very low. The chassis of reverse osmosis devices is made of stainless steel. It is on all the equipment required for its operation.

Osmosis has a very important role in the life of living things in nature. It is difficult to understand Reverse Osmosis without knowing the principle of OSMOSIS. The osmosis (transition) phenomenon works flawlessly in many places in nature, such as plant roots taking water from the soil, exchanging fluid from the blood to nourish the cells in the body, separating blood from urine in the kidneys. With OSMOSIS, the waters in the soil open the membrane on the root of the plant and enter the waters in the plant, which are more saline. However, the pressure of the water in the soil is less than the pressure of the water at the root of a high tree. Despite this, the little mineral water in the soil enters the root of even the tree at a height of 100 meters, and thus the tree receives the water and minerals it needs and continues its life. This natural phenomenon proves that water with fewer minerals has a pressure compared to more mineral water. Thanks to this osmotic pressure arising from the difference in salinity (mineral) of waters, water under the same atmospheric pressure easily passes through the membrane (i.e. membrane) that separates living things or cells to the other side. In this case of nature, the law of compound vessels as we know between a membrane and separated waters does not apply.

With Reverse Osmosis (CTR) devices, it is possible to obtain good water from very bad and salt waters by reversing this natural phenomenon. As in the diagram, if we divide a container in half with a semi-permeable TO membrane, putting seawater on one side and pure water on the other, we need to apply pressure to the seawater side to prevent the pure water from passing to the seawater side. Devices manufactured with this technique, called Reverse Osmosis, are encountered in many places in the world and in our country from power plants to textile dyehouses, from soft drink production to drinking water production.

The way the CTR device works is similar to the way the kidneys work in humans and animals. The kidney separates harmful objects from the blood and with a little water excretes them from the body as urine. The CTR device also separates minerals from the water and needs some water to be able to expel them. If there is not enough water to expel minerals, stones form in CTR, just like kidney stones.

04.02. Reverse Osmosis Membrane

Reverse osmosis systems based on membrane filtration are fed by pressurized flow to parallel the membrane surface. Part of this flow tends to pass through the membrane. Particles and dissolved minerals that cannot pass through the membrane leave behind a concentrated solution. The concentrated solution flows parallel to the surface of the membrane. Thus, dissolved minerals and particles are prevented from accumulating on the membrane.

Reverse osmosis membranes act as a barrier against all dissolved salts, inorganic molecules and organic molecules with a molecular weight greater than about 100. Water molecules, in other words, molecules that can pass freely through the membrane, form the purified production flow. The efficiency of reverse osmosis systems to separate water molecules from dissolved salts is 95%