RO Water Treatment Plant

RO Water Treatment Plant in Bangladesh

RO Water Treatment Plant is a broadly known technology in Bangladesh. Most of the industrial areas found polluted water. It is quite difficult to get perfect water for using industrial purposes. It is possible to remove up to 99% impurity from polluted water by RO Water Treatment Plant. Most of the peoples claim RO make huge wastewater. But modern RO Technology has proven it can recover up to 90% water pure water. It is also widely accepted for the wastewater treatment process. Such as wastewater recycle plant, zero liquid discharge, and so on. Before considering the RO Water Treatment Plant in wastewater in Bangladesh should consider some parameters. Such as level of Total Dissolve Solid (TDS), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD). Besides that, Total Suspended Solid (TSS), Mixed Liquor Suspended Solids (MLSS), Color, and some other parameters. The industrial waste discharge naturally contains between 500 to 15000 ppm TDS. The modern Reverse Osmosis Technology can remove all particles up to 99%. So, we can reuse the wastewater as freshwater for our industry.

About Our Plant

RO water plant is a special treatment process specifically in Bangladesh. The technology and equipment of RO water treatment plant is depending on water quality. The RO equipment is to pass raw water through a fine filter, granular activated carbon filter, compressed activated carbon filter, etc., and then pressurize it through a pump. The reverse osmosis membrane (RO membrane) with a pore size of 1 / 10000 m (equivalent to 1 / 6000 of the size of Escherichia coli and 1 / 300 of the size of a virus) changes high concentration water into low concentration water, At the same time, industrial pollutants, heavy metals, bacteria, viruses, and other impurities mixed into the water are all isolated, so as to meet the physical and chemical indicators and health standards for drinking, and produce pure to pure water, which is the best choice for the human body to supplement high-quality water in time, The cleanliness is almost 100%, so people call this kind of water production machine reverse osmosis water purification machine.  

System Composition of RO Water Treatment Plant

Pretreatment system

Pre-Treatment is the most important issue for RO Water Treatment Plant due to water quality is different in Bangladesh. It generally includes a raw water pump, dosing device, quartz sand filter, activated carbon filter, precision filter, etc. Its main function is to reduce the pollution index of raw water and other impurities such as residual chlorine to meet the requirements of reverse osmosis. The equipment configuration of the pretreatment system should determine according to the specific situation of raw water. So, it is important to the proper design of the Pre-treatment system.

Reverse osmosis equipment

It mainly includes a multistage high-pressure pump, reverse osmosis membrane element, membrane shell (pressure vessel), support, etc. Its main function is to remove the impurities in the water and make the effluent meet the use requirements.

Post-processing system

It is mainly composed of a cleaning water tank, cleaning water pump and precision filter. When the RO water treatment plant is polluting in Bangladesh and the effluent index cannot meet the requirements, it is necessary to clean the RO system to restore its efficiency.

Cleaning system

It is mainly composed of a cleaning water tank, cleaning water pump and precision filter. When the RO water treatment plant pollutes in Bangladesh and the effluent index cannot meet the requirements, it is necessary to clean the RO system to restore its efficiency.

Electric control system

It is useing to control the normal operation of the whole reverse osmosis system. Including instrument panel, control panel, various electrical protection, electrical control cabinet, etc.

The typical process of RO Water Treatment Plant

Raw water tank

Storage of raw water used to precipitate large sediment particles and other precipitable substances in water. At the same time, it can buffer the impact of unstable water pressure in raw water pipes on the water treatment system. (such as the reaction of pressure sensor caused by too low or too high-water pressure).

Raw water pump

It works to deliver the water to pre-treatment of RO water treatment plant. Constant system water supply pressure, stable water supply.

Multi-media filter

The main purpose of the filter with multiple filter layers is to remove the sediment. Such as, rust, colloidal substances, suspended solids and other. Substances with particles above 20um in the raw water. Manual valve control or full-automatic controller is useing for backwashing, forward flushing and other operations. Ensure the water quality of the equipment and extend the service life of the equipment. There are many kinds of media for multi-media filters, such as Birm media, Irox N-70, DMI-65, Zeomangan and so on.

Activated carbon filter

The system uses shell activated carbon filter, activated carbon can not only adsorb electrolyte ions but also carry out ion exchange adsorption. The oxygen demand (COD) of potassium permanganate can also reduce from 15 mg / L (O2) to 2 ~ 7 mg / L (O2) by activated carbon adsorption. In addition, the concentration of adsorbed and duplicated surface increasing by adsorption, which can also play a catalytic role in removing pigment, peculiar smell, a large number of biochemical organic compounds, reducing residual chlorine value and pesticide pollutants, and removing trihalide (THM) and other pollutants in water Things. Manual valve control or full-automatic controller select for backwashing, forward flushing and other operations. Ensure the water quality of the equipment and extend the service life of the equipment. At the same time, the equipment has a self-maintenance system, and the operation cost is very low. So, in the RO water treatment plant, it is very important.

Ion softening system/dosing system

For the purpose of concentrated discharge of dissolved solids and utilization of fresh water in R / O unit, in order to prevent the concentration product of CaCO3, MgCO3, MgSO4, CaSO4, BaSO4, SrSO4 and siso4 at the concentrated water end, especially at the concentrated water side of the last membrane module of reverse osmosis equipment, from exceeding its equilibrium solubility constant, resulting in crystallization and precipitation, and damaging the proper characteristics of the membrane element, before entering the reverse osmosis membrane module, The crystal precipitation of carbonate, SiO2 and sulfate prevent by ion softener or appropriate scale inhibitor

Precision filter

The precision filter useing to remove the suspended solids, non-straight particles and colloids in the influent, which makes the operation of RO system and other follow-up equipment safer and more reliable. The filter element is a 5um melt blown filter element, which aims to remove the impurities larger than 5um from the upper filter unit. Prevent it from entering the reverse osmosis equipment and damaging the surface of the membrane, thus damaging the desalination performance of the membrane.

Reverse osmosis system

Reverse osmosis equipment uses enough pressure to separate the solvent (generally water) in the solution through a reverse osmosis membrane (or semi-permeable membrane). Because this process is opposite to the direction of natural osmosis, it is called reverse osmosis. Reverse osmosis can adapt to all kinds of the salt content of raw water, especially in the high salt content of water treatment projects, can obtain good technical and economic benefits. The reverse osmosis process has the advantages of high desalination rate, high recovery rate, stable operation, small floor area and simple operation. The reverse osmosis equipment can remove most bacteria, colloids and high molecular weight organics while removing salt.

Ozone sterilizer / ultraviolet sterilizer (optional)

Kill the bacteria produced by secondary pollution, and ensure the sanitary index of finished water

Cleaning Method of RO Water Treatment Plant

In the background of Bangladesh if thinking treatment plant of RO Water really difficult to maintain. The character of raw water is totally different in different areas. So, it may require cleaning the Reverse Osmosis Plant. In Bangladesh due to brackish water, the RO technology stands as mandatory to fulfill the required demand. The cleaning problem of reverse osmosis water purification equipment may make many users who are not strong in technology suffer losses.

Low-pressure flushing reverse osmosis equipment

Regular flushing of RO equipment with a high flow rate, low pressure, and low pH value is beneficial to remove the fouling on the membrane surface and maintain the membrane performance. When the SDI of RO equipment suddenly rises more than 5.5, low-pressure flushing should carring out, and the machine startsing after the SDI value adjusting to qualify.

Shutdown protection of reverse osmosis equipment

Due to the fluctuation of production, the reverse osmosis equipment will inevitably be shut down frequently. When it is shut down for a short time or a long time, protective measures take. Improper treatment will lead to the degradation of membrane performance and irrecoverable.
Short term preservation is suitable for the system that has been out of service for less than 15 days. The reverse osmosis equipment protects by low-pressure flushing every 1-3 days. It is found that when the water temperature is above 20 ℃, the water in reverse osmosis equipment will stink and deteriorate after 3 days of storage, and a large number of bacteria will breed. Therefore, it suggests that when the water temperature is higher than 20 ℃, low-pressure flushing should carry out every 2 days or 1 day. When the water temperature is lower than 20 ℃, low-pressure flushing should carry out every 3 days. After each flushing, all inlet and outlet valves on the reverse osmosis equipment of the water purification equipment will close.
The long-term shutdown protection is applicable to the system that has been shut down for more than 15 days. At this time, the protection solution (bactericide) must fille with into the water purification equipment and the reverse osmosis equipment for protection. The commonly used bactericide formula (composite membrane) is formaldehyde 10 (mass fraction), isothiazolinone 20mg / L, sodium bisulfite 1 (mass fraction).

Chemical cleaning of reverse osmosis membrane

Under normal operation conditions, reverse osmosis membrane may also pollutes by inorganic scale, colloid, microorganism, metal oxide, etc. these substances deposited on the membrane surface will cause the output of water purification equipment to reverse osmosis equipment to drop or desalination rate to drop, pressure difference to rise, and even cause irrecoverable damage to the membrane. Therefore, in order to restore good water permeability and desalination performance, it is necessary to carry out chemical treatment on the membrane Learn to clean.