TSS in palm oil wastewater can be a significant operational challenge for palm oil mills. High concentrations of total suspended solids can increase sludge loading, affect downstream biological treatment, and contribute to fouling when membrane processes are used. Effective removal therefore requires more than simply adding chemicals. The treatment process needs to match the characteristics of the wastewater and the performance requirements of the overall system.
For palm oil mills, particularly those treating palm oil mill effluent (POME), controlling TSS early in the treatment process can help improve downstream treatment performance and make effluent quality more consistent.
Why Is TSS High in Palm Oil Wastewater?
POME contains a complex mixture of suspended and colloidal materials, organic compounds, oil and grease, and other contaminants. Suspended solids can include fibrous and cellulosic materials generated during palm oil processing.
A 2017 study found that POME can contain approximately 2 to 4% suspended solids, with a substantial portion consisting of cellulosic compounds that may not be readily degraded through conventional biological treatment.
This makes TSS control an important consideration before wastewater enters subsequent treatment stages.
High TSS can lead to several operational issues:
- Higher solids loading on biological treatment systems
- Increased sludge production
- Greater turbidity in treated effluent
- Reduced treatment efficiency when solids interfere with downstream processes
- Potential membrane fouling in membrane-based treatment systems
For this reason, TSS removal in palm oil wastewater treatment is often most effective when addressed through appropriate pretreatment.
Read Also: What are the Impacts of High TSS and Turbidity in Raw Water?
How to Remove TSS in Palm Oil Wastewater Treatment
The most suitable TSS removal process depends on the wastewater characteristics, required effluent quality, and existing treatment system. In practice, several treatment stages can work together.
1. Screening and Primary Separation
The first step is to remove larger solids before they enter the chemical or biological treatment stages.
Screens, grit removal, and primary settling can help separate larger suspended materials and reduce the solids burden on downstream units.
However, simple settling may not be sufficient when a significant portion of the TSS consists of fine or colloidal particles. These particles can remain suspended because of their small size and surface characteristics.
2. Coagulation and Flocculation
When fine suspended particles are difficult to settle, coagulation-flocculation can be used to improve their separation.
During coagulation, chemicals destabilize suspended and colloidal particles. Flocculation then brings these particles together to form larger flocs that can be separated through sedimentation or other solid-liquid separation processes.
Research has demonstrated the potential of coagulation-flocculation for TSS removal from POME. A 2017 study using polymer-induced coagulation reported up to 96.4% TSS removal under optimized laboratory conditions.
Another study published in 2019 investigated coagulation-flocculation as a pretreatment for POME and evaluated the use of rice husk ash and alum.
However, chemical selection and dosage should not simply be copied from laboratory studies. POME characteristics can vary between mills, processes, and operating conditions.
3. Optimizing Chemical Dosage Through Jar Testing
One of the most practical steps for improving TSS removal is determining the appropriate coagulant and flocculant dosage through jar testing.
Instead of relying on a fixed chemical dosage, jar testing can evaluate:
- Coagulant type
- Coagulant dosage
- Flocculant type and dosage
- pH
- Mixing conditions
- Floc formation
- Settling characteristics
- TSS removal performance
This approach helps identify a treatment condition that provides effective solids removal without unnecessary chemical consumption.
A study on hybrid coagulation-ultrafiltration treatment of POME, for example, reported 99.74% TSS reduction during the optimized coagulation stage using PAC before membrane treatment.
The specific dosage and operating conditions should not, however, be treated as universal values. Site-specific wastewater testing remains important.
Don’t Treat TSS Removal as a Standalone Process
Effective TSS control should be considered as part of the overall wastewater treatment system.
For example, when membrane treatment is used, controlling suspended solids before the membrane stage can help reduce the solids loading reaching the membrane. Research on POME treatment has also highlighted membrane-based systems as an option for producing higher-quality treated effluent, although membrane performance depends strongly on operating conditions and fouling control.
This means the objective is not simply to achieve the highest possible TSS removal at one treatment stage. The better approach is to determine where TSS should be removed, how much should be removed, and how the removal process affects the rest of the system.
Read Also: How to Reduce TSS in Wastewater for More Stable Treatment Performance
A Treatment Approach Based on Your Wastewater Conditions
For palm oil mills dealing with high TSS, the most effective solution may involve a combination of physical separation, coagulation-flocculation, clarification, filtration, biological treatment, or membrane processes.
The right combination depends on factors such as:
- Raw POME characteristics
- Existing treatment configuration
- TSS concentration
- COD and BOD levels
- Oil and grease content
- Required final effluent quality
- Sludge handling capacity
- Operating and chemical costs
This is where treatment optimization becomes important. Rather than applying a one-size-fits-all chemical program, wastewater treatment should be evaluated as an integrated process.
Supporting Better TSS Control with LAI
At Lautan Air Indonesia (LAI), wastewater treatment can be approached from both the chemical and operational sides. Our water treatment expertise can support palm oil mills in evaluating treatment conditions, selecting suitable treatment chemicals, and optimizing coagulation and flocculation processes based on actual wastewater characteristics.
Through laboratory testing and application support, the treatment program can be developed around the mill’s existing process and target effluent quality, rather than relying only on standard chemical dosage.
The objective is simple: more effective solids separation, more stable treatment performance, and better control of downstream operational challenges.
Need to Improve TSS Removal in Your Palm Oil Wastewater Treatment?
If high TSS is affecting your wastewater treatment performance, LAI can help evaluate the treatment process and identify opportunities for improvement.
Contact Lautan Air Indonesia to discuss about your palm oil wastewater treatment requirements and explore a treatment approach suited to your operation.
Reference
- Zinatizadeh, A. A., et al. (2017). Polyacrylamide-induced coagulation process removing suspended solids from palm oil mill effluent. Separation Science and Technology, 52(3), 520–527.
- Huzir, N. M., et al. (2019). Optimization of coagulation-flocculation process for the palm oil mill effluent treatment by using rice husk ash. Industrial Crops and Products, 139, 111482.
- Palm Oil Mill Effluent Treatment Processes: A Review. Processes, 9(5), 739, 2021.
- Ng, L. Y., et al. (2022). Performance of Membrane Bioreactor in Palm Oil Mill Effluent Treatment: An Overview. Journal of Applied Membrane Science & Technology, 26(2), 11–16.
