Membrane Technology – Reverse Osmosis and Nanofiltration

AMV and REVERSE OSMOSIS PLANTS

EXPERIENCE, EXPERTISE and BENEFITS in DESALINATION

WATER IS INDISPENSABLE TO LIFE

WATER TREATMENT BY MEMBRANE TECHNOLOGY (RO, NF)

The raw water available from low salinity-, brackish water-, high saline surface- or well water sources is, however, in almost every case not directly – never for sea water – suitable for drinking purposes and in no case suitable for specific industrial usage without specific water treatment processes.

The objective of water treatment by Reverse Osmosis process is to produce safe and fresh potable water on the one hand and fulfilling the quality requirement of industrial water usage on the other hand, using most developed and implemented membrane processes.

Generally to desalinate surface or well water (e.g. sea-, brackish- or low salinity tap water) by membrane processes, frequently high qualified pre-treatment is essential, to protect the membranes from fine clay and sand particles, organic and inorganic fouling, but also from scaling, membrane degradation and other undesired influences caused by most diverse substances contained in the raw water source. Well designed pre-treatment not only is protecting the membranes, but also increase their efficiency in productivity and therefore lowering the operation and service costs of the whole system significantly.

Further environmental measure is to reduce energy- and chemical consumption during operation.

AMV provides complete Reverse Osmosis Systems to be used for:

a- communities and cities to provide potable water

b- different industries to provide preliminary- or final step of process water qualities

AMV REVERSE OSMOSIS DESALINATION PLANTS

AMV Reverse Osmosis desalination plants are used in the development of different water sources using most updated membrane technologies combined with other processes necessary, providing safe and adequate drinking water for Cities, Communities, but also process waters for different kind of Industries.

AMV provides technological advances in general, but not limited to:

Pre-Treatment by MF, UF, DAF, Conventional Pre-treatment, like Coagulation, Flocculation, Sedimentation, Granular Filtration, Softening, and Pre-conditioning upstream to the RO.

Main Treatment containing and Micro-filtration, high pressure pumping combined with different technologies of energy recovery, single or multistage Reverse Osmosis systems, incl. CIP system.

Post Treatment like re-mineralization, pH adjustment and disinfection by different disinfection processes as well as conditioning for concentrate produced, etc..

WHICH ADVANTAGES AMV CAN PROVIDE

35 Years Experience in RO Plant Design
High Efficiency Reverse Osmosis Systems to increase the output and simultaneously reduce the raw water input
Standard RO Systems
Customer Made RO Solutions
Wide range of Pre-Treatment Processes
Supplying Single Compartments
Economical solutions
Technical and commercial optimized solutions for complete plants but also for individual designs
Support of the civil parners involved in a project (civil guide line drawings, etc.)
Cooperation with International well established Sub-contracting Partners
Flexible and Professional Development of solutions for individual technologies
Professionality, Reliability and Adherence to Schedules
High Qualified Personal for supervision services for installation
Professional Training for operators
Competent Supervision for the commissioning phase
Service
Project Management

Of course the engineers of AMV provide the advice combining the right treatment steps, ensuring the client to receiving the required water qualities considering the technical and commercial targets.

WHAT AMV CAN SUPPLY

Considering complete RO systems we divide the processes into the following superior sections:

Water Intake Systems (Option)
Chemical Conditioning
Pre-Treatment
Main Membrane Process
Post Treatment
By Product Removal – in case of chlorine disinfection
Extended Treatment – in case higher/highest water quality is required like pure or ultra pure waters

a- Water Intake System (Option)

The Water Intake System sending the raw water to the individual treatment sections is classified into the following systems:

Open Sea Intake
Beach Well
Deep Well
Shallow Well
River Water Intake
Dams

Seawater intake

For any seawater desalination plant, one of the major important subject is selection of the best possible intake system. It has great effect on the investment for pre-treatment units and finally on the efficiency and lifetime of the desalination plant. In any individual location, careful studies and tests must be carried out to select the most suitable seawater intake in the available nearby shores. Unfortunately because of the apparent simplicity, the importance of intake on the location, design and performance of the pre-treatment and desalination plant is often underestimated.

Seawater intake can be classified as follows:

Subsurface Intakes

By using shallow or deep wells at the nearby shores or for small desalination plants, using artificial ground filter. In this case, the available seawater is acutally filtered water and does need any sophisticated pre-treatment system .

Open seawater intake

If enough subsurface water is not available, seawater should be intaked directly from the sea. Quality of seawater from suspended solids and colloidal particles points of view, specially during storming conditions, is quite different along the shoreline and inside the sea far from shore. Due to the shape, natural formation of shore and depth of water, the content of non dissolved solids changes considerably.

So by frequent sampling and testing, the most suitalbe intake point with lower suspended solids and distance to the shore must be indicated. Anyhow fine strainers should be used at the suction of intake pumps and on the discharge point, seawater should be disinfected just on the intake jetty.
b- Pre-Treatment

In the Pre-Treatment section, particles, suspended solids, turbidity as well as micro-organism shall be reduced in the raw water providing the requested standard for RO feed water. Depending on the raw water quality, the pre-treatment sections shown below shall be combined or selected as single pre-treatment step:

Screening systems – for removing of course particles
Sieve systems – e.g. micro strainers for removing of fine suspended solids
Grit removal – removal of minarally matters
Pre-Disinfection – Ozonation units or Hypochlorite dosing stations are used
pH/ORP-Adjustment
Oxidation (of Iron and Manganesecompounds, removal of undisirable odour and taste as well as dissolved gases, etc.)
Pre-Sedimentation System for Turbidity > 100 NTU
Dissolved Air Flotation (DAF)
Coagulation, Flocculation, Sedimentation
Granular Media Filtration (SMF, DMF, MBF, GSF (Green sand))
Powdered media filtration (diatomaceous earth)
Activated Carbon Filter (ACF)
Ultra-Filtration (UF)
Micro-Filtration (MF)
Ion exchange processes (e.g. softening, mainly but not limited to industrial purposes)
De-Alkalization

c- Chemical Conditioning

The Chemical Conditioning shall be involved preventing colloidal and particulate fouling as well as scaling caused by sparingly soluble salts inside the membranes:

pH-Adjustment
De-Chlorination in case using
Antiscalant Dosing

d- Main Treatment Process

The Main Treatment Process will remove dissolved salts can be expressed by the below shown steps in the membrane filtration:

Micro- (Cartridge-) Filtration (MF)
High Pressure Pumping (HPP)
Energy Recovery (ER) RO Energy Recovery – Turbocharger I.JPG (3,5 MB)
Nano-Filtration (NF)
Reverse Osmosis (RO)
Membrane Cleaning (CIP)

e- Post Treatment

The Post Treatment shall put the permeate coming from the RO to the final desired quality as follows:

pH-Adjustment for Permeate and Concentrate
Re-Mineralization
Disinfection – by different technologies disinfection – Chlorination system, UV disinfection but also Ozonation can be used successfully.

The above mentioned treatment sections (b-) and (c-) are an indication of the most common and new technologies in the water pre-treatment, upstream to Reverse Osmosis system. Due to the wide range of possible impurities in the raw water, but also physical conditions, most of the solutions have to be selected individually by combining the above mentioned treatment steps. Only this policy will ensure, together with a well prepared water analysis, an optimum working plant.

In case of raw water pollutants e.g. Ammonia, Iron, Manganese, Colour, Odour, dissolved Gases etc., either a selection of compartments in connection to the main plant can be used or we supply a separate plant to remove any specific problem.

WHERE AMV CAN ASSIST

Process- and Plant Design
Civil Guide Line Drawings
Highly skilled Supervision for Erection
Training for Operators
Professional Supervision for Commissioning
After Sales Services

REVERSE OSMOSIS PLANT DESIGN

AMV RO systems are designed principally on the available environmental European Standards.

The RO plants to remove dissolved salts and organics significantly, whereas the pre-treatment section is responsible to remove suspended solids, turbidity and other impurities from the available raw water in each area, harmful for Reverse Osmosis membranes, providing a treated water quality according to WHO standards for potable water and qualities as requested for other purposes.

All the components selected are of highest possible grades and quality, tested and certified, as well as in accordance with the local rules and regulations.

Selected Materials are suitable in the usage for the individual usage in chemical dosing stations, pumping stations, piping, valves,

The applied design criteria and the components of a Reverse Osmosis water treatment plant depend on the turbidity, salinity and pollution of a known raw water source.

SIZE OF PLANTS

Sea Water Desalination Plants are designed for capacities:

from 200 m³/d up to 10.000 m³/d

Exceptional also for higher capacities

In case of Brackish Water Desalination, the plant capacities may reach a permeate production:

from 200 m³/d up to 25.000 m³/d.

REQUIRED INFORMATION FOR THE PLANT DESIGN

A complete raw water analysis, as well as other general information, is required to design a suitable process for the raw water treatment. AMV offers the related questionnaire on request.

The minimum required data for our design are:

Raw water source and the related physical and chemical water analysis, TDS and SDI as a minimum.
Average daily water consumption during dry- and wet season
Required treatment plant capacity in [m³/d]
Average Turbidity in [mg/l]
Average Suspended Solids content in [mg/l]
Any required water quality standards for the treated water (when different to WHO)
Where to dispose, or any possible usage, for the back wash waters, concentrate, etc.

PLANT CONSTRUCTION

AMV RO Stationary-, Containerized-, or Package Plants consist of pre-fabricated skids, either coated with epoxy resin or being of stainless steel, inter-connecting pipes & fittings for low pressure piping made of GRP/PE/PVC, high pressure piping made of Duplex/Super-Duplex/SMO, equipment like different types of pumps, energy recovery systems, mixers, valves, process units like ultra-, micro-, and nano-filtration systems, dosing stations, measuring & control instruments, electric cabinets, Scada system, power and control cables and other parts and components which are designed and delivered as a complete functionally plant.

At site, the mentioned parts and equipment will be mounted and assembled together and put on concrete foundations.

PLANT OPERATION

AMV Reverse Osmosis Plants have been designed for easy operation, considering the possibilities available also in remote areas. After plant start up period, the operation shall be carried out, depending on the size of plant, by an experienced plant operator and a group of skilled technicians but also semi-skilled workers. Of course, during the plant start up period, we train the operator staff and any available skilled technician.

TREATED WATER QUALITY & USAGE

The treated water is in the one hand prepared to be used for drinking water, according WHO standard, or on the other hand based on the specific quality requirement for industries.

Excess waters like back wash water usually can be disposed to the sewerage system because of using food grade chemicals.

Concentrate can be sent back to the raw water source after conditioning.