Category Archives: News

In every water treatment process, both for domestic and industrial needs, the existence of a clarifier system is very vital. A clarifier is one of the important components in the initial stages of water purification which functions to separate suspended solids from liquids through the sedimentation process.

Without a clarifier, this separation process would be much more difficult, require more energy, and risk reducing the overall efficiency of the water treatment system.

What is a Clarifier and How Does It Work?

A clarifier is a tool or system designed to remove suspended solid particles in water or waste through the gravity sedimentation process. Water containing particles enters the clarifier, where the flow rate is slowed down.

In this slow flow condition, solid particles have enough time to settle to the bottom of the tank due to the influence of gravity.

The way a clarifier works generally consists of several main stages:

• Inlet Zone: Water enters through an inlet designed to spread the flow evenly throughout the tank.
• Settling Zone: In this zone, water moves slowly and allows heavy particles to settle to the bottom of the tank.
• Sludge Zone: Sediment collected at the bottom will be collected as sludge.
• Effluent Zone: Clear water at the top of the tank will flow out of the system for the next purification stage.

Clarifiers can be used in clean water treatment (water treatment plants) or in wastewater treatment plants, depending on the needs and characteristics of the water being treated.

Types of Clarifiers

There are two main types of clarifiers that are commonly used in water treatment systems: primary clarifiers and secondary clarifiers. Both have complementary roles in the purification process.

1. Primary Clarifier

Primary clarifiers are used in the early stages of wastewater treatment. Its function is to remove coarse solids and organics that can interfere with biological processes in the next stage. At this stage, around 50-70% of total suspended solids (TSS) and around 25-40% of Biochemical Oxygen Demand (BOD) can be reduced.

The characteristic of the primary clarifier is its large, round or rectangular design, equipped with a sludge collection system and a skimming cleaner on the surface to remove fat or oil.

2. Secondary Clarifier

After biological processes such as aeration, wastewater still contains active biomass in the form of biological sludge. This is where the secondary clarifier works—separating the microorganism sludge from the clean water from decomposition. This sludge can be returned to the aeration process or disposed of as final sludge (waste activated sludge).

Secondary clarifiers usually have a similar design to primary clarifiers, but focus more on the efficiency of separating microorganism sludge so that the resulting water can be continued to the filtration or disinfection stage.

Read Also: Why Solids Floating in Secondary Clarifiers?

Clarifier Applications in Various Sectors

Clarifier systems are widely used in various sectors, especially:

1. Municipal Wastewater Treatment

In domestic wastewater treatment plants, clarifiers are essential to maintain the stability and effectiveness of the overall process. Primary clarifiers are used to reduce the organic load before entering the aeration unit, while secondary clarifiers play a role in separating the sludge from the biological process.

2. Food and Beverage Industry

This industry produces waste with high organic content. Clarifiers are used to precipitate food residues, fats, and other organic compounds before further processes such as filtration or disinfection.

3. Chemical and Petrochemical Industry

Clarifiers help remove chemical solids and heavy particles from process water or waste, thus preventing damage to downstream systems and meeting environmental discharge standards.

4. Textile and Paper Industry

In this industry, clarifiers are used to precipitate residual dyes, fibers, and chemicals from wastewater before being discharged into rivers or further processed.

5. Raw Water Treatment

Before water from rivers or lakes is used as raw water for clean water production, a clarifier can be used to reduce TSS and turbidity, making the next filtration stage easier.

Read Also: Raw Water Treatment System: The Initial Solution for Quality Water

Benefits of Using a Clarifier

Integrating a clarifier into a water treatment system provides many real benefits, including:

1. Efficiently Reducing Water Turbidity

A clarifier helps separate solid particles suspended in the water, making the water clearer and ready to enter the next treatment stage.

2. Improving Advanced Treatment System Performance

By reducing the particle load from the start, the filtration, biological, or chemical systems in the next stage can work more optimally and last longer.

3. Saving Operational Costs

Effective use of a clarifier helps reduce the need for additional chemicals and minimizes the frequency of maintenance or equipment damage.

4. Meeting Environmental Standards

A clarifier helps maintain the quality of treated water or wastewater to comply with the standards set by regulations, especially in reducing TSS, BOD, and COD levels.

5. Supporting Process Stability

By separating sludge regularly, the clarifier helps maintain process stability and makes it easier to manage sludge overall.

Want Your Clarifier to Work More Efficiently? Trust the Experts

A poorly maintained or disturbed clarifier system can cause a domino effect—from decreased quality of treated water, spikes in operational costs, to potential environmental pollution. For this reason, proper maintenance and technical support are crucial.

Lautan Air Indonesia is here as a partner to ensure your clarifier system is working at its best performance. With more than 41 years of experience in the field of water treatment, we have been trusted by various industrial sectors in Indonesia to handle complex technical problems.

Contact us now for technical consultation, clarifier audit requests, or periodic maintenance services. Our team is ready to come to your location with fast and accurate solutions.

In various industries and sectors of society, the availability of clean and safe raw water is very important to support the production process and other operational needs.

However, raw water from rivers, lakes, reservoirs, or other natural sources generally contains various contaminants such as mud, organic materials, heavy metals, and microorganisms that can harm the system and reduce process efficiency. Therefore, a reliable and integrated raw water treatment system is needed so that the water can be utilized optimally.

Lautan Air Indonesia, with more than 41 years of experience in the air treatment industry, is present as a trusted partner in providing effective, efficient raw water treatment solutions that are in accordance with the specific needs of each customer.

What is a Raw Water Treatment System?

A raw water treatment system is a system designed to process raw water from natural sources into water that is suitable for use for various purposes, such as industrial processes, coolers, boilers, and even further processing into drinking water.

This system aims to remove or reduce the content of suspended solids (Total Suspended Solids/TSS), organic materials, microorganisms, heavy metals, and other unwanted chemical compounds.

This raw water treatment system is the first and most crucial stage in the entire air treatment system. Without good raw water treatment, the efficiency of advanced systems such as RO, demineralization, and heating and cooling systems can be disrupted due to the accumulation of abrasive, corrosive, or scaling impurities.

What is included in the Basic Raw Water Treatment System?

The raw water treatment system consists of several main components that work synergistically. Each part has a specific function and is designed to handle certain types of contamination. Here are the basic elements of a raw water treatment system.

1. Chemical Dosage

Chemicals are important elements to help the coagulation, flocculation, disinfection, and pH adjustment processes. Some types of chemicals commonly used include:

• Coagulants (eg: Poly Aluminum Chloride/PAC, Aluminum Sulfate): bind fine particles into larger clumps for easy sedimentation.
• Flocculants (eg: anionic/cationic polymers): help form stable and rapidly settling flocs.
• Disinfectants (eg: chlorine, sodium hypochlorite): kill pathogenic microorganisms.
• pH adjusters (acid or base): keep the air pH at the optimal range for the treatment process.

2. Clarification (Initial Sedimentation System)

Clarifier is a unit that functions to sediment suspended solids resulting from the coagulation and flocculation process. In this system, solid particles that are heavier than air will settle by gravity to the bottom of the tank.

The clearer water will flow to the next stage. This system can be in the form of a circular clarifier, tube settlement, or lamella clarifier, depending on the capacity and land area requirements.

Read Also: Clarifier in the Water Industry: Function, Types, and Applications

3. Filtration System (Filtering System)

After passing through the clarifier, the air is directed to the filtration unit to remove any remaining fine particles. The filtration system can be:

• Filter media: using silica sand, anthracite, activated carbon, or DMI-65.
• Cartridge or bag filter: for precision applications with small to medium capacities.
• Automatic backwash filter: for large capacity systems with continuous operation requirements.

4. Control Panel & Instrumentation

To ensure the entire process runs efficiently, the raw water treatment system is equipped with an automatic control panel and instrumentation. These components include:

• Flow meter, pH meter, turbidimeter
• PLC and HMI for automatic control
• Alarm system and failure protection
• Integration with SCADA or IoT systems (if required)

With automatic control, customers can monitor air quality and quantity in real-time, and adjust process parameters quickly.

How Does Raw Water Treatment Work?

The raw water treatment process begins with taking water from a natural source, which then goes through a series of stages as explained below:

1. Intake & Screening

Raw water is first taken through an intake system, usually equipped with a screen or coarse filter to catch large debris such as leaves, wood, and plastic.

2. Chemical Dosing

After going through the intake, the water is flowed into a rapid mixing tank where coagulant and flocculant chemicals are added. This process aims to form floc particles from fine suspensions in the water.

3. Clarification

The water mixed with chemicals enters the clarifier, where floc sedimentation occurs. The settled solids are collected and removed periodically, while the cleaner water moves to the next stage.

4. Filtration

The clarified water is filtered using filter media to remove remaining particles and improve water clarity (turbidity). At this stage, activated carbon can also be used to remove odors, colors, and certain organic compounds.

5. Disinfection & pH Adjustment

The final step in raw water treatment is disinfection, to ensure that no pathogenic microorganisms remain. In addition, pH adjustment is carried out so that the water meets the specified quality standards.

6. Distribution or Further Processing

Water that has gone through the processing process is then channeled to the utilization system, such as a boiler, chiller, or further processes such as RO and demineralization.

The Foundation of Quality Water Starts with Raw Water Treatment

Raw water treatment is a critical stage that should not be ignored in the water treatment process chain. This system not only functions to filter and remove contaminants from source water, but also forms the basis for the efficiency of further systems such as Reverse Osmosis, Demineralization, Boilers, or Chillers. With the right design and selection of appropriate technology, companies can save operational costs, extend equipment life, and maintain the stability of the production process.

However, the success of raw water treatment is highly dependent on understanding the characteristics of raw water and the implementation of an integrated system, starting from the chemicals used, equipment such as clarifiers and filters, to accurate automatic controls.

That’s why partnering with an experienced solution provider like Lautan Air Indonesia is a strategic move. We not only offer products and technology, but also provide a holistic approach that includes system design, chemical supply, installation, training, and operation and maintenance (O&M) services.

Read Also: Why Demineralized Water Still Contains Silica

Trust Your Raw Water Treatment to the Experts

With over 41 years of experience and a service network throughout Indonesia, Lautan Air Indonesia is ready to help you face various raw water quality challenges. We understand that every water source has unique characteristics, and every industrial process has different standards. Therefore, we offer customized, tested, and guaranteed sustainable solutions.

Want to know more about how we can help your project? Contact our team for a direct consultation and get the best solution for your facility’s raw water treatment system.

Algae in cooling water systems is often considered a minor nuisance that is easy to overcome. However, in reality, uncontrolled algae growth can be one of the main causes of decreased efficiency in industrial cooling systems.

Algae grow rapidly in a supportive environment: warm temperatures, sufficient light, and the availability of nutrients such as phosphate and nitrate. This combination is often found in cooling tower systems that do not have adequate biological protection.

Without realizing it, the algae biofilm that forms can block water flow, reduce heat transfer, and accelerate corrosion and fouling on pipes and equipment. The impact? Increased energy consumption, more frequent maintenance, and equipment damage that requires expensive replacement.

Risks That Occur If Left Untreated

If not handled systematically, algae problems not only reduce efficiency but also threaten the sustainability of industrial operations.

Some real risks that often arise due to algae contamination include:

1. Decreased heat exchanger efficiency

The algae layer that sticks to the surface of the heat exchanger acts as an insulator, inhibiting the heat transfer process. This causes the system to work harder, consuming more energy.

2. Increased operational costs and downtime

Manual cleaning of algae-infested systems takes time and effort, sometimes requiring a shutdown for a thorough cleaning process.

3. Increased risk of microbiological corrosion (MIC)

Algae and other microorganisms form biofilms that create an anaerobic environment at some points in the system, triggering pitting corrosion that is difficult to detect until it is severe.

4. Potential violation of environmental standards

Effluent from cooling systems contaminated with excessive algae can exceed water quality thresholds set by environmental regulations, risking sanctions.

With such complex risks, it is clear that algae prevention cannot be taken lightly. It requires an integrated approach that is not only reactive but also proactive.

Read Also: How to Control Algae and Biofilm in Raw Water Treatment Systems

Cooling Tower Algae Prevention Solutions

Preventing algae growth in cooling tower systems requires a holistic approach, combining physical, chemical, and operational measures. Algae can grow rapidly when conditions are favorable — warm water, the presence of nutrients such as phosphate and nitrate, and exposure to sunlight. Here are the main steps in preventing their growth:

1. Nutrient Control

Algae require nutrients such as phosphate and nitrogen to thrive. One of the most effective ways to prevent their growth is to control the concentration of nutrients in the water. This can be done by:

• Ensuring the make-up water source is free from high-nutrient contaminants.
• Maintaining a consistent blowdown program to reduce nutrient accumulation.

2. Biocide Application

Biocides are chemicals designed to inhibit or kill microorganisms, including algae. There are two main types:

• Oxidizing biocides (e.g., chlorine, bromine): kill algae quickly and are very effective, but must be monitored to prevent damage to system materials.
• Non-oxidizing biocides (e.g., isothiazolin, glutaraldehyde): work more slowly but are effective for long-term prevention and control of biofilms.

The use of biocides must be done in rotation or alternately to prevent microbial resistance.

Read Also: What is Shock Load and Its Effects on Wastewater Treatment Plants

3. Control pH and Water Chemistry

Maintaining water pH in the optimal range (usually between 6.5–8.5) can inhibit algae growth. In addition, controlling other chemical parameters such as alkalinity, hardness, and total dissolved solids (TDS) is important to prevent the creation of an environment that supports biological growth.

4. Reducing Sunlight Exposure

Because algae require light for photosynthesis, limiting direct sunlight exposure to the cooling tower is an effective preventive measure. This can be done by:

• Use a cover or light shield on the open part of the cooling tower.
• Redesigning the open area to reduce the intensity of incoming light.

5. Periodic Filtration and Blowdown System

Filtration helps filter out solid particles and microorganisms before they enter the main system.

Blowdown is the process of removing some of the circulating water containing dissolved solids and contaminants. Performed periodically, blowdown helps maintain low concentrations of substances that support algae growth.

6. Physical Cleaning and Periodic Maintenance

Performing regular cleaning of the cooling tower, especially on the water surface area and tower walls, can inhibit the formation of biofilms and algae colonies. Periodic maintenance includes:

• Scrubbing or brushing the surface.
• Draining and refilling the system at certain times.
• Periodic inspections are conducted to detect early signs of microorganism growth.

7. Physical Disinfection

Non-chemical disinfection such as:

• UV light: Damages algae DNA and prevents replication.
• Ozonation: Oxidizes microorganisms in water, effectively without leaving residues.

This technology can be used as a complement to chemical programs for comprehensive protection against microorganisms.

8. Real-Time System Parameter Monitoring

The application of sensors and automatic controls allows the system to detect fluctuations in water quality, such as pH, temperature, biocide concentration, and turbidity levels. Real-time monitoring provides accurate information needed to make quick decisions, including when to add biocide or perform blowdown.

9. Operator Training and Clear SOPs

The human factor also plays an important role. Operators must understand the SOPs for algae control, chemical use, and the importance of preventive measures. Regular training and documented procedures help maintain consistency and quality of cooling tower system operation.

Prevention is Better than a Cure

Algae growth in cooling water systems is not a small problem that can be ignored. Its impact on energy efficiency, system reliability, and operational costs is significant. Therefore, a comprehensive and sustainable prevention approach is needed.

With the support of technology, the right chemical treatment, and an experienced team of experts, Lautan Air Indonesia is ready to be your trusted partner in keeping your cooling system clean, efficient, and free from algae.

With more than 40 years of experience in industrial water treatment, Lautan Air Indonesia understands that each cooling system has its own characteristics and challenges. We not only sell products, but also offer integrated solutions, from system design, chemical selection, equipment installation, to monitoring and after-sales support.

Don’t wait until your cooling system stops due to an algae attack. Contact the Lautan Air Indonesia team today for a consultation and find the right solution for your cooling water systems needs.

In wastewater treatment processes, stability is the main key to the success of the system. One of the biggest challenges that can disrupt this stability is shock load—a condition when the load entering the wastewater treatment system increases suddenly, either in quantity or quality. This event can cause significant disruption to biological and chemical processes, even causing the failure of the system as a whole.

This article will discuss in more depth what shock load is, its types, the challenges it poses, and the best solutions to overcome it.

What is Shock Load?

Shock load is a condition where the amount and/or characteristics of wastewater entering a wastewater treatment plant (WWTP) change drastically in a short time. These changes can be in the form of:

• Surge in volume (hydraulic shock load)
• Increased levels of organic matter (organic shock load)
• Entry of toxic or hazardous substances (toxic shock load)
• Extreme pH changes
• Excessive nutrient levels

If not handled properly, this condition can disrupt microorganisms that play an important role in the biological process of wastewater treatment.

Types of Shock Loads in WWTP

Shock loads can come from various sources and in various forms. Here are some of the most common types of shock loads that occur in wastewater treatment facilities.

1. Hydraulic Shock Load

This type of shock load occurs when the volume of wastewater entering the system increases suddenly, exceeding the design capacity. This surge is often caused by heavy rainfall, pipe leaks, or large amounts of industrial activity at certain times.

The impacts:

• Disrupts hydraulic residence time (HRT)
• Causes leaching of microorganisms from biological reactors
• Increases the load on the clarifier system

2. Organic Shock Load

Occurs when the amount of organic matter (such as BOD and COD) increases drastically in a short period of time. Usually caused by the discharge of production waste without pre-treatment or very high concentrations of organic matter.

Impact:

• Stress on microorganisms
• Decreased efficiency of biological treatment
• Increased risk of spoilage and odor

3. Toxic Shock Load

The entry of toxic substances such as heavy metals, industrial chemical compounds, detergents, or disinfectants in large quantities can kill or inhibit the activity of microorganisms.

Impact:

• Death of active biomass
• Decreased quality of effluent
• Long-term disruption of biological processes

4. pH Shock Load

Sudden changes in wastewater pH (too acidic or alkaline) will cause an environment that is not conducive to microorganisms.

Impact:

• Denaturation of microbial enzymes
• Death of sensitive organisms
• Termination of the nitrification/denitrification process

5. Nutrient Shock Load

Although nutrients are necessary for the growth of microorganisms, too high concentrations, especially nitrogen and phosphorus, can cause an imbalance in the microbiological ecosystem in the reactor.

Impact:

• Excessive algae growth
• Decreased efficiency of biological treatment
• Increased aeration requirements

Challenges Caused by Shock Load

Shock load not only causes temporary disruptions but can also have a systemic impact on the performance and sustainability of WWTP operations. The following are the main challenges caused by shock load, classified into several important categories.

1. Process Disturbance

A sudden surge in waste load can disrupt the stability of biological and chemical treatment processes. In biological units, the community of microorganisms that function to decompose organic pollutants is very sensitive to drastic changes, both in terms of COD/BOD concentration, toxicity, and pH.

Some of the disturbances that occur include:

• Decreased efficiency of biological reactors
• Death of microorganisms due to toxicity or extreme pH
• Significant decrease in DO (Dissolved Oxygen) levels
• Accumulation of undegraded organic matter

2. Sludge Management

Shock load often increases the production of excess sludge, both from biological and physicochemical processes. The sudden increase in sludge volume will complicate the drying, handling, and disposal processes. Common effects:

• Overload on the sludge separation system (clarifier, DAF, filter press)
• Decreased sludge quality (low dewaterability level)
• Increased sludge discharge frequency → increased operational costs

Read Also: How to Overcome High Sludge Volume Index (SVI) in Wastewater Treatment

3. Compliance Issues

Shock loads can cause effluent quality parameters to exceed environmental quality standards set by regulations (eg PermenLHK). This has the potential to cause administrative and legal sanctions, as well as a bad image for the company.

Common problems that arise

• COD, BOD, TSS, Ammonia, and fatty oil (FOG) levels increase at the outlet
• Ph fluctuations that are not in accordance with standards
• Failure to report or record data due to unexpected spikes

4. Environmental Impacts

Decreased wastewater quality due to shock loads can have significant environmental impacts, especially if it is discharged directly into water bodies without further treatment. Potential impacts include

• Eutrophication of waters due to spikes in nutrients (N and P)
• Death of aquatic biota due to toxicity or decreased DO
• Unpleasant odors that spread to the surrounding environment
• Pollution of soil or groundwater if waste enters the infiltration path

5. Dependence on Manual Intervention

In many cases, the response to shock loads is still carried out reactively and manually, such as adding emergency chemicals, flushing, or bypassing certain systems. This risks causing operational errors, increasing operator workloads, and increasing dependence on short-term interventions.

6. Increased Operational Costs

The combination of all the challenges above often results in a significant spike in operational costs. Starting from the purchase of additional chemicals, the cost of sludge suction, to the cost of repairing disrupted systems.

Solutions to Overcome Shock Load in WWTP

Managing shock load requires a comprehensive strategy that includes early detection, technical control, and collaboration between production and waste processing teams. The following are comprehensive solutions that can be applied:

1. Balancing Tank and Equalization

The use of balancing tanks or equalization tanks functions to accommodate wastewater before entering the main process. This provides mixing and homogenization time, so that load spikes can be reduced.

2. Online Monitoring System

One of the best ways to detect shock load early is to apply online sensors for parameters such as pH, COD, DO (Dissolved Oxygen), and discharge. With continuous monitoring, operators can take quick action before system damage occurs.

Read Also: How to Optimize the Nitrification and Denitrification Processes in Wastewater Treatment

3. Automatic Dosing System

To deal with organic or pH shock loads, an automatic dosing system with reagents such as coagulants, flocculants, alkalis or pH-adjusting acids can be integrated into the system.

4. Biological Unit Upgrade

If shock loads occur frequently, the biological unit can be upgraded to a more robust system such as:

• Moving Bed Biofilm Reactor (MBBR)
• Sequencing Batch Reactor (SBR)
• Membrane Bioreactor (MBR)

This system has higher resistance to load fluctuations than conventional activated sludge systems.

5. Training and SOP Prevention

One common cause of shock load is operational negligence. With regular training and the preparation of the right Standard Operating Procedure (SOP), the potential for shock load can be reduced.

Conclusion

Shock load is a real challenge that can occur at any time in the WWTP system. The impact can damage the biological unit, reduce the quality of the effluent, and cause increased costs and legal risks. Therefore, a deep understanding and the right handling strategy are very important.

With an integrated approach and more than 40 years of experience in the field of water treatment, Lautan Air Indonesia is present as a trusted solution for the industry in dealing with shock load.

Contact Lautan Air Indonesia today for a consultation on a WWTP solution that is robust and adaptive to dynamic waste loads. Make your wastewater treatment system more ready to face challenges, protect the environment, and support sustainable industrial production.

In the world of wastewater treatment, the Sludge Volume Index (SVI) parameter is an important indicator for assessing the quality of activated sludge. SVI measures the ability of sludge to settle after the aeration process in mL/g units. The ideal SVI value is generally in the range of 80–150 mL/g. However, when the SVI value increases significantly above that number—for example, reaching 200 or more—the system begins to show signs of serious disturbance.

High SVI is one of the most common problems faced in wastewater treatment plants (WWTPs), both in the industrial and domestic sectors. A high SVI value indicates that the sludge has poor settling ability, causing the processed water to become cloudy and not meet quality standards.

The Real Impact of High SVI in WWTP Operations

Sludge Volume Index (SVI) is not just a numeric parameter in a laboratory report. When the value is outside the optimal limit—especially when it is too high—SVI becomes an early indicator of biological imbalance that can affect the entire performance of the wastewater treatment system. The impact is not only technical, but also has direct implications for operations, costs, and compliance with environmental regulations.

Some of the real consequences of high SVI include:

1. Decreased Separation Efficiency in the Secondary Clarifier

A high SVI indicates that activated sludge has poor settling ability. This causes the separation process between clear water and sludge to not run optimally. Sludge tends to remain in the liquid phase (carry over), so that the quality of the effluent coming out of the system can contain high suspended solids (TSS), sometimes even causing wastewater to look cloudy or foamy.

2. Increased Risk of Sludge Bulking

High SVI is often associated with sludge bulking conditions, where the sludge floc becomes too light or not compact, due to the dominance of certain microorganisms such as filamentous bacteria. Sludge bulking not only inhibits the sedimentation process, but can also cause sludge accumulation downstream and disrupt further processes.

Read Also: Why is the Activated Sludge in Wastewater Treatment Plant Not Sedimenting Properly?

3. Increased Operational Costs

When the treatment system has to work harder to overcome the declining effluent quality, the logical consequence is increased costs. The use of additional chemicals, increased frequency of desludging, or even the need for biological system reactivation are factors that increase operational burdens. Not to mention the potential investment in equipment or system modifications to overcome long-term impacts.

4. Decreased Stability of Biological Processes

High SVI reflects unbalanced microbiological conditions. This imbalance can reduce the efficiency of the biodegradation process in the aeration reactor. As a result, organic compounds that should be decomposed can pass to the final stage and increase the Chemical Oxygen Demand (COD) or Biochemical Oxygen Demand (BOD) in the effluent.

5. Risk of Non-Compliance with Environmental Quality Standards

The most serious impact of high SVI is the potential for violation of environmental quality standards set by the government. Failure to meet parameters such as TSS, COD, or BOD can result in administrative sanctions, fines, or even termination of facility operations. This will certainly have a negative impact on the company’s reputation and business continuity.

Integrated Approach to Control High SVI

Dealing with high SVI values ​​requires a comprehensive and measured approach. It is not enough to just intervene with one aspect such as aeration or adding chemicals, because the cause of high SVI can involve many factors—starting from the composition of wastewater, the characteristics of microorganisms, to the operational conditions of the installation itself.

Here are some technical strategies that are commonly applied to control and reduce SVI.

1. Microbiological Analysis of Activated Sludge

The first and most important step is to analyze the microbiological condition of activated sludge. Microscopic examination will help identify the types of microorganisms that dominate, including the presence of filamentous bacteria which are often the main cause of high SVI.

This examination can also reveal sludge conditions such as floc structure, floc size, and the presence of other suspended particles that are not properly degraded.

2. Bio-Augmentation with Selective Microorganisms

When it is known that high SVI is caused by the dominance of filamentous microorganisms, the bio-augmentation approach can be an effective solution. This technique involves the addition of non-filamentous competitor microorganisms that help balance the population in the activated sludge and improve floc quality.

Bio-augmentation should be carried out based on the results of microbiological analysis and the specific conditions of each WWTP system.

Read Also: How to Control Algae and Biofilm in Raw Water Treatment Systems

3. Nutrient Optimization and C:N:P Ratio

Nutrient balance greatly influences the growth of healthy microorganisms in the activated sludge system. An imbalance in the ratio of carbon (C), nitrogen (N), and phosphorus (P) can encourage the growth of unwanted types of bacteria, including filamentous bacteria.

Evaluation and adjustment of the nutrient ratio need to be done periodically, especially in systems that receive high organic waste loads or waste from certain industrial processes that are low in nitrogen or phosphorus.

4. Precise Dissolved Oxygen (DO) Control

The level of dissolved oxygen in the aeration tank also plays an important role in the balance of the microbial ecosystem. Oxygen that is too low can stimulate the growth of anaerobic or microaerophilic microorganisms, including some filamentous species. Conversely, excess DO can also cause the formation of non-compact flocs.

The use of DO sensors and automatic control systems can help maintain the stability of these parameters continuously.

5. Selective Use of Chemicals

In some cases, the addition of chemicals such as mild oxidizers (low doses of chlorine, hydrogen peroxide, or permanganate compounds) can be used to suppress the population of filamentous bacteria. The use of these chemicals must be done very carefully and not long-term, because it risks disrupting microorganisms that play an important role in the biodegradation process.

This approach is usually applied as a short-term recovery step while preparing a more sustainable solution.

6. Routine Monitoring and Evaluation

High SVI is often an accumulation of small changes that have been ignored for a long time. Therefore, it is important to implement a daily monitoring system and periodic evaluation of all process parameters, from influent characteristics, aeration performance, to sludge quality in the secondary clarifier.

Investment in monitoring systems and operator training is an important part of maintaining long-term system stability.

Want to Manage SVI with More Control?

Maintaining the performance of a wastewater treatment system requires a deep understanding, consistent monitoring, and the right technical approach. If you are facing challenges related to high SVI values ​​or want to improve the efficiency of the wastewater treatment process as a whole, there is nothing wrong with discussing with parties who have extensive experience and insight in this field.

Lautan Air Indonesia is here as a technical partner who can help you find solutions based on data analysis, industry experience, and an integrated approach.

Contact our technical team to get initial insights or further discussions about solutions that suit your wastewater treatment system.