Makassar’s industrial wastewater treatment is defined by a 16,000 m³/day municipal WWTP (under construction) and decentralized systems like DEWATS, which operate at 10–20% of design capacity (250–500 m³/day vs. 2,500 m³/day). To meet PermenLHK No. 68/2016 effluent limits (e.g., BOD ≤30 mg/L, COD ≤100 mg/L), industrial facilities must design systems for influent variability (e.g., COD 500–5,000 mg/L) and land constraints (e.g., DEWATS requires 21 m² for 50 households). Hybrid systems (e.g., DAF + MBR) achieve 90–98% COD removal, while zero-discharge designs add RO or evaporation for 99%+ water recovery. The geographical location of Makassar, as a coastal gateway to Eastern Indonesia, further complicates discharge logistics, as high salinity in groundwater can interfere with traditional biological processes, making advanced engineering solutions a necessity.
Makassar’s Industrial Wastewater Challenge: Capacity Gaps and Compliance Risks
Makassar’s municipal wastewater infrastructure currently centers on a 16,000 m³/day treatment plant under construction, which leaves the majority of industrial facilities reliant on localized decentralized systems.Data from decentralized wastewater treatment systems (DEWATS) in the region, such as those in Abbulo Sibatang, reveal a significant performance gap: while designed for 2,500 m³/day, these systems often operate at only 250–500 m³/day and produce effluent with a COD of 148.06 mg/L. This exceeds the 100 mg/L limit mandated by PermenLHK No. 68/2016, posing immediate legal and environmental risks for facility managers. The environmental impact is particularly severe for the Tallo River and the Losari Beach area, where uncontrolled discharge leads to eutrophication and the degradation of local marine ecosystems.
The industrial sectors driving Makassar’s economy—primarily food processing, textiles, and metalworking—generate high-strength wastewater with COD levels ranging from 500 to 5,000 mg/L. Standard anaerobic systems or gravity-based DEWATS are insufficient for these loads. For instance, food processing facilities in the Makassar Industrial Estate (KIMA) produce high concentrations of Fats, Oils, and Grease (FOG), which coat biological media and trigger system failure. These FOG concentrations often peak during high-production shifts, leading to "slug loads" that can kill the microbial populations in traditional activated sludge plants. To achieve compliance, facilities must transition toward hybrid DAF-MBR systems to treat organic wastewater effectively, ensuring that pretreatment stages remove solids before biological polishing.
Beyond technical limitations, there is a growing socio-economic pressure on industries in Makassar. As urban sprawl surrounds previously isolated industrial zones, odor control and noise pollution have become critical compliance factors. Traditional open-air lagoons are no longer acceptable due to the release of hydrogen sulfide (H2S) and methane. The Indonesian government’s increasing focus on "Green Industry" certification means that non-compliant facilities risk losing their operational permits or facing heavy fines under the Job Creation Law (UU Cipta Kerja), which has tightened environmental oversight.
Land availability presents a secondary but critical challenge in Makassar’s urban and industrial zones. Traditional treatment ponds are often non-viable; even a small-scale DEWATS for 50 households requires approximately 21 m² of land. For an industrial facility processing 500 m³/day, the land footprint for conventional activated sludge could exceed 1,000 m². Engineers are increasingly turning to modular WSZ series systems for land-constrained industrial projects in Makassar, which utilize underground configurations to preserve surface area for manufacturing operations while meeting the strict BOD ≤30 mg/L limit. These modular systems allow for vertical scaling, utilizing deep-tank aeration or stacked clarifiers to maximize throughput per square meter of footprint.
Engineering Specs for Industrial Wastewater Treatment in Makassar: Influent, Effluent, and System Sizing
Industrial wastewater in Makassar requires specific engineering design parameters that account for high influent variability and the region's tropical climate.In tropical environments, the "Alpha factor"—the ratio of oxygen transfer in wastewater versus clean water—is typically lower (0.4 to 0.6), necessitating larger aeration blowers and finer bubble diffusers to maintain the required Dissolved Oxygen (DO) levels of 2.0 mg/L. Designing for PermenLHK No. 68/2016 requires a precise understanding of the raw waste stream. Food processing facilities in the region typically report TSS between 300 and 1,200 mg/L and FOG levels up to 800 mg/L. Without high-efficiency pretreatment, these parameters lead to rapid membrane fouling and sludge bulking in secondary treatment stages.
System sizing must follow rigorous hydraulic and organic loading calculations. For biological systems such as Membrane Bioreactors (MBR), a Hydraulic Residence Time (HRT) of 6–12 hours is standard for COD concentrations up to 2,000 mg/L. However, for the high-strength streams (COD >3,000 mg/L) found in Makassar’s textile or concentrated food sectors, HRT must be extended or paired with a ZSQ series DAF system for high-efficiency TSS/FOG removal to reduce the organic load before it reaches the bioreactor. Proper sizing also requires accounting for "Peak Hourly Flow" during facility wash-down periods, which can be 3 to 4 times the average daily flow rate. Without equalization tanks sized for at least 25-30% of daily volume, the biological system risks hydraulic washout.
The following table outlines the design targets required to bridge the gap between raw industrial influent and legal discharge limits, reflecting the specific challenges of Makassar's key sectors:
| Parameter | Food Processing Influent | Textile Influent | PermenLHK 68/2016 Limit |
|---|---|---|---|
| pH | 4.5 – 8.5 | 9.0 – 12.0 | 6.0 – 9.0 |
| COD (mg/L) | 1,500 – 5,000 | 800 – 3,000 | ≤ 100 |
| BOD (mg/L) | 800 – 2,500 | 400 – 1,200 | ≤ 30 |
| TSS (mg/L) | 300 – 1,200 | 200 – 600 | ≤ 30 |
| FOG / Oil (mg/L) | 200 – 800 | 50 – 150 | ≤ 5 (Industry specific) |
| Total Nitrogen (mg/L) | 50 – 150 | 20 – 60 | ≤ 30 |
To ensure system stability in Makassar’s high-humidity environment (75–85%), aeration systems must be oversized by 15–20% to compensate for reduced oxygen transfer efficiency. Sludge management is a critical engineering spec; in the tropics, sludge stabilizes quickly but can also go septic rapidly if not handled. Engineers must specify Mean Cell Residence Times (MCRT) of 15 to 25 days for MBR systems to ensure complete nitrification. For Reverse Osmosis (RO) units intended for zero-discharge, a membrane flux of 15–25 LMH (liters per square meter per hour) is recommended to manage the high scaling potential of Makassar's groundwater, which is often used as process water. Engineers should also calculate for a 70–85% recovery rate, ensuring that the brine stream is manageable for subsequent evaporation or specialized disposal. The use of antiscalants and periodic Acid/Alkali Clean-in-Place (CIP) cycles is mandatory to maintain these flux rates over the long term.
Hybrid System Designs for Makassar: DAF + MBR vs. MBR + RO for Zero-Discharge Compliance
In this setup, the Dissolved Air Flotation (DAF) unit removes 90–95% of TSS and FOG, protecting the subsequent integrated MBR systems for PermenLHK No. 68/2016 compliance in Makassar. The MBR stage then utilizes a high Mixed Liquor Suspended Solids (MLSS) concentration of 6,000–10,000 mg/L to degrade dissolved organics, consistently producing effluent with BOD <10 mg/L. This high MLSS concentration allows the system to handle organic shocks that would otherwise cause a conventional clarifier to fail due to sludge bulking.
For facilities pursuing zero-liquid discharge (ZLD) or significant water reuse, the MBR + RO stack is the technical benchmark. The MBR acts as an advanced pretreatment for the RO membranes, removing virtually all suspended solids and most organic carbon, which reduces RO membrane fouling. This is particularly vital for metalworking facilities in Makassar that need to remove heavy metals and dissolved salts for process water recycling. The RO stage typically involves a two-pass system or a high-pressure single pass to achieve Total Dissolved Solids (TDS) levels below 50 mg/L, making the water suitable for boiler feed or high-precision cooling towers.
Implementing these hybrid systems requires a sophisticated control strategy. Programmable Logic Controllers (PLCs) are used to synchronize the DAF chemical dosing (coagulants and flocculants) with the influent flow rate, ensuring that the MBR is never overloaded. In Makassar, where power stability can be an issue in certain industrial pockets, systems should be designed with "auto-restart" capabilities and emergency bypasses to prevent untreated discharge during outages. The integration of remote monitoring is also becoming a standard requirement, allowing plant managers to track effluent quality in real-time and adjust aeration or sludge wasting rates from a mobile device, ensuring 24/7 compliance with PermenLHK No. 68/2016.
Finally, the choice between DAF+MBR and MBR+RO depends on the facility's ultimate goal. If the goal is simply legal discharge to a water body or the KIMA sewer line, DAF+MBR is the most cost-effective solution. However, if the facility faces water scarcity or high municipal water costs—common issues in Makassar during the dry season—the MBR+RO system provides a significant return on investment by reducing raw water procurement costs by up to 80%. This dual benefit of environmental compliance and resource recovery is driving the next generation of industrial infrastructure in South Sulawesi.
Recommended Equipment for This Application
The following Zhongsheng Environmental products are engineered for the wastewater challenges discussed above:
- Sludge dewatering solutions for PermenLHK No. 68/2016 compliance in Makassar — High-pressure filtration designed to reduce sludge volume by 70-80%, critical for facilities with high disposal costs.
- Submersible Aeration Units — Specifically designed for high-temperature tropical wastewater to maximize oxygen transfer.
- Chemical Dosing Skids — Automated systems for pH adjustment and coagulant delivery, optimized for textile and food processing influent.
Need a customized solution? Request a free quote with your specific flow rate and pollutant parameters. Our engineering team can provide a full site assessment to determine the optimal hybrid configuration for your facility.
Related Guides and Technical Resources
Explore these in-depth articles on related wastewater treatment topics:
- Compare Makassar’s WWTP costs with Bandung’s 2026 benchmarks
- See how Jubail’s zero-discharge projects compare to Makassar’s compliance challenges
- Advanced Membrane Cleaning Protocols — A technical guide on extending the life of MBR and RO units in high-salinity coastal environments.
- PermenLHK No. 68/2016 Compliance Checklist — A step-by-step guide for facility managers to ensure all discharge parameters are monitored correctly.
