Membrane services

A membrane is defined to be a selective barrier, usually a thin film, that allows certain components of a mixture to pass through, but hinders the permeation of other components, thus achieving a separation. 

Different types of membranes and processes are used to clean surface water, groundwater and wastewater. The material transported through the membrane is affected by the driving force acting upon it. Pressure-driven membrane processes are most commonly established. This technology uses membranes with highly specialized characteristics to remove particles through physical separation.

There are mainly four types of membranes – reverse osmosis (RO), nanofiltration (NF), ultrafiltration (UF) and microfiltration (MF). RO is a commonly used technique to generate drinking water from groundwater. It utilizes pressure to separate water from all other materials including bacteria, spores, salts etc., NF, also known as Membrane Softening, is similar to RO, however it allows some salts to pass through while rejecting larger molecules. Under UF technique the pores are large and the pressure in which the liquid passes through them is relatively lesser. It allows salts, sugars, organic acids to pass through the membrane while restricting proteins and fats. In MF, substances like suspended solids, bacteria and fat globules are filtered out through the pores. 

As desalination becomes a key source for clean water, Ultrafiltration (UF) / Nanofiltration (NF) / Reverse Osmosis (RO) membrane plants will be an integral part of water infrastructure worldwide. However, RO plant operation often reveals a troubled history of under delivery, interrupted production and unplanned cost increases due to higher consumption of energy and chemicals, event-driven unscheduled membrane replacement, degrading performance and shortened membrane lifetime.

Plant owners and operators face constant pressure to save costs in terms of membrane replacements, consumables, energy and labour. Moreover, utilising common system-oriented operating KPIs is not enough for driving sustainable optimisation. UF / NF / RO membrane elements are critical to plant performance, yet their condition is largely unknown and only indirectly measurable, as operations do not allow inspection of the complex physical-chemical processes inside the elements. This lack of comprehensive UF / NF / RO membrane condition documentation is a major disadvantage when seeking to optimise plant performance and engaging with membrane, chemical and other component suppliers.

At TÜV SÜD we help water treatment plant owners and operators with continuous monitoring of membranes through in-house accredited laboratories and technical advisory services drawing upon extensive plant operating and troubleshooting experience. 

To realise significant and sustainable optimisation potential that exists in a UF / NF / RO plant, deep understanding of the membrane element lifecycle is essential. A sustained element-oriented understanding enables optimisation efforts to be qualified and quantified in a risk-mitigated manner. As an independent and impartial technical advisor, we are not tied to any vendor technologies. Our only agenda is the performance of your plant. 

TÜV SÜD offers complementary services focused on the characterisation of the membrane element and aimed at maintenance optimisation. The unique value-maximising potential of the UF / NF / RO plant optimisation draws on the insights gained from element characterisation.

Our Membrane Services include:

• Continuous membrane element characterisation

  A structured condition test programme is conducted on select UF / NF / RO elements in our accredited labs providing consistent and comparable information on each element condition. This detailed history supports preventive maintenance measures and Root Cause Analysis if performance degrades.

• Membrane autopsy

  An essential to every membrane plant, over 20 specific tests are conducted on different types of membranes for fouling issues or reduced performance. Through this technique, membranes are thoroughly analysed to determine root cause of the problem and mitigation measures are developed accordingly.  

• Sustained fact-based UF / NF / RO plant optimisation 

  Leveraging your operating team’s experience, we develop an integrated, prioritised optimisation programme targeting savings in consumables, energy and labour. Once the plant’s operating history has been documented sufficiently, an optimised operation and maintenance strategy is developed. It is prepared as a business case synthesising technical / financial / risk considerations and sensitivities.