Fault Diagnosis of Reverse Osmosis Water Treatment System

Due to the complexity of operating conditions, reverse osmosis water treatment systems can experience malfunctions during operation. Factors such as imperfect system design, inappropriate pretreatment equipment configuration, unsuitable water treatment reagent selection, abnormal fluctuations in the system's water source, and various problems encountered during operation can all lead to system failures, resulting in decreased desalination rate, reduced permeable water output, increased inlet pressure, and increased energy consumption per unit of water production. Kaiyuan Hengye, leveraging its years of experience in reverse osmosis system design, installation, and operation, employs professional technical analysis methods to conduct detailed analysis and diagnosis of various malfunctions occurring during the operation of reverse osmosis water treatment systems. Simultaneously, solutions are provided through static and dynamic simulation tests.

Historical Data Analysis

The operation of a reverse osmosis unit is a process of generating historical data. During this process, changes in various performance characteristics of the reverse osmosis system and various factors that may lead to system failures are often reflected in this data. In particular, analysis of the following historical data is crucial:

1. Changes in routine analysis data of turbidity, SDI, and COD of the reverse osmosis (RO) unit feed water;

2. RO unit feed water pressure, intermediate stage pressure (for a one-stage, two-stage system), concentrate pressure, and product water pressure;

3. RO unit feed water conductivity, product water conductivity, feed water flow rate, and product water flow rate;

4. Changes in operating parameters of the RO pretreatment system (including turbidity and pressure);

5. Problems typically discovered during equipment maintenance and the methods used to address them, etc.

The above data is often insufficient. More information is needed depending on changes in on-site conditions. After obtaining the above data, specialized processing methods (such as standardization) are often required to observe operational trends and propose solutions.

On-site Investigation

When historical data analysis results do not match the actual fault phenomena, on-site investigation is an important method. Investigation items include:

1. The rationality of the reverse osmosis unit's design;

2. The rationality of the reverse osmosis pretreatment system design;

3. Whether the operating procedures are complete;

4. Whether the reverse osmosis system's chemical dosing is normal, whether the added chemicals are compatible with the system, and whether the pretreatment flocculant is compatible with the reverse osmosis additives (scale inhibitors, dispersants, bactericides, reducing agents);

5. The configuration of the reverse osmosis pre-filter (security filter) cartridge, etc.

The above data is often insufficient; more information is needed depending on changes in the actual situation.

Water Quality Analysis

In addition to the above two analyses, further analysis of the source water, reverse osmosis feed water, and other possible water source conditions is required. Analysis items mainly include: turbidity, SDI, COD, Ca2+, Mg2+, Sr2+, Ba2+, SO42-, alkalinity, silica, etc. In our central laboratory, all these water quality analysis items that may cause system failure will be tested one by one; at the same time, the influent and effluent water quality and flow rate of each membrane shell (reverse osmosis pressure vessel) in the reverse osmosis unit will be analyzed in more depth.