Sewage Treatment Methods: What India Can Learn From Other Developing Nations

BLOG August 11, 2025

In this article, we will explore various low cost sewage treatment options implemented in other developing nations, examine how different countries approach aeration tank design, compare effluent treatment plant models, and analyze the effectiveness of various treatment of sewage water techniques. By studying these approaches, we can identify sustainable solutions to expand India’s sewage treatment infrastructure.

Sewage treatment methods have become increasingly critical as over 2 billion people worldwide lack access to adequate wastewater treatment systems. While developed nations like those in the European Union connect approximately 75% of their population to centralized sewage systems, developing countries often rely on decentralized solutions or have no treatment infrastructure at all.

India faces significant challenges in this area. Despite producing 72,368 MLD (million liters per day) of sewage, the country’s installed treatment capacity stands at just 31,841 MLD, covering only 43.9% of the total volume. Additionally, 60% of this treatment capacity is concentrated in just five states and one Union Territory.

However, India has made notable progress with certain technologies. India is a leading country in municipal sewage treatment using UASB, which has been recognized as the most cost-effective sewage treatment approach for our environmental conditions. This technology forms the core of our national environmental efforts under the Yamuna Action Plan, accounting for 80% of the total treatment capacity (743,000 m³/d).

Current State of Sewage Treatment in India

The sewage treatment infrastructure in India exhibits a significant gap between generation and treatment capacity, creating serious environmental and public health concerns across the nation.

Low treatment coverage in tier-2 and rural areas

Urban sewage generation has reached alarming levels, with an estimated 72,368 million liters per day (MLD) being produced nationwide ¹. Unfortunately, the treatment capacity stands at merely 31,841 MLD in class-I cities and class-II towns ¹. This disparity is even more pronounced in smaller communities, where treatment facilities are virtually non-existent. Furthermore, the operational capacity is only 26,869 MLD, meaning just 28% of generated wastewater receives proper treatment ².

Rural areas face even greater challenges, often relying on poorly maintained on-site sanitation systems like pit latrines or septic tanks that frequently leak or overflow ³. Consequently, untreated or inadequately treated sewage flows directly into open drains, agricultural fields, and nearby water bodies ³.

Technology distribution: ASP, SBR, MBBR, UASB

India employs various sewage treatment methods across its operational plants. The main technologies include Activated Sludge Process (ASP), Sequencing Batch Reactor (SBR), Moving Bed Biofilm Reactor (MBBR), and Upflow Anaerobic Sludge Blanket (UASB) ⁴.

UASB technology has gained significant traction in India, with approximately 985 MLD capacity already operational and about 20 more plants in the pipeline ⁵. Moreover, India is recognized as one of the leading countries globally in terms of sewage volume treated through the UASB process ⁵.

ASP-BNR, SBR, MBBR, and MBR systems demonstrate superior capabilities in achieving BOD <20, SS<20, and removing 70-80% of total nitrogen ⁴. SBR technology offers advantages in effluent quality, flexibility, and energy costs compared to competing technologies ⁴.

Treatment Technologies by Installed Capacity and Number of STPs

Technology	Installed Capacity (MLD)	Number of STPs	% of Installed Capacity
SBR	10,638	490	29%
ASP	9,486	321	26%
UASB	3,562	76	10%
MBBR	2,032	201	6% ⁶

Challenges in land availability and O&M costs

Land scarcity remains a major obstacle for expanding sewage treatment infrastructure, especially in densely populated urban areas ⁷. To address this issue, multi-storey treatment plants have emerged as an innovative solution, reducing land requirements by approximately 54% compared to conventional designs ⁷.

Operation and maintenance (O&M) costs present another significant challenge. UASB plants require annual O&M expenses of less than 1% of capital costs, roughly 30% of what ASP-based plants demand ⁵. Nonetheless, maintenance across all technology types is often neglected, leading to equipment failure, offensive odors, and untreated discharge ⁸.

Technical expertise also poses a concern, as many STPs are operated by personnel lacking adequate knowledge beyond basic pump and motor operation ⁷. This technical deficit results in suboptimal performance, with approximately 39% of plants failing to meet environmental discharge standards ⁷.

Cost-Effective Technologies Used in Other Developing Nations

Several developing nations have successfully implemented affordable and efficient sewage treatment methods that India can learn from. These countries have adapted technologies to their unique economic, geographic, and climatic conditions.

UASB adoption in Brazil and Indonesia

Brazil stands at the forefront in utilizing Upflow Anaerobic Sludge Blanket (UASB) technology for wastewater management. The Betim Central sewage treatment plant, designed to process 514 L/s of influent flow, demonstrates exceptional performance with remarkable removal efficiencies: 94% for BOD, 91% for COD, 92% for total suspended solids, and 72% for ammonia ⁹. This system combines UASB with activated sludge treatment, creating an effective hybrid approach.

Why UASB is preferred?:

Compact design: Suits Brazil’s often mountainous landscapes and dense urban areas.

Cost-effective: Capital costs for building UASB-based WWTPs range widely (R$60 to R$650 per inhabitant), but UASB is consistently favored for its lower investment and operational cost, particularly in small-to-medium municipalities.

Climatic advantage: Brazil’s warm climate enables optimal anaerobic digestion performance and biogas production.

Simplicity and robustness: Suitable for a wide range of municipality sizes and effluent flow rates.

Brazilian pulp and paper industries have likewise embraced UASB reactors since the 1980s, requiring investments of merely 6.8% of annual sales while delivering returns within 6.4 years ¹⁰. In Indonesia, three 1.2 m³ UASB units tested in Bandung achieved high treatment efficiencies due to excellent sludge stabilization and retention ¹¹.

Constructed wetlands in Kenya and Nepal

Kenya has adopted constructed wetlands (CWs) as cost-effective solutions primarily in municipalities, industries, hotels, and farms. ¹² These systems excel at pathogen removal with 99.83% E. coli elimination rates ⁹. Notably, CWs offer multiple advantages: simple construction, low maintenance costs, ability to handle fluctuating flows, and excellent esthetic appearance ¹². Nepal, under UN-HABITAT’s Water for Asian Cities Program, has implemented CWs as strategic nature-based solutions ¹³. Although implementation faces challenges including weak legislation and low hygienic standards, these systems remain viable alternatives where conventional treatment plants are non-functional ¹⁴.

Drivers for adoption:

Cost-effectiveness and environmental benefits

Potential for water reuse and biodiversity enhancement

Suitability for remote areas not serviced by centralized sewage networks

Challenges:

Limited scale of adoption beyond select locations

Technical expertise and land availability

Managerial attitudes and seasonal variations in wastewater volume

Decentralized systems in Vietnam and Bangladesh

Vietnam has pioneered decentralized wastewater management approaches, particularly in Hanoi where two case studies highlight community involvement in decision-making and management . These initiatives capitalize on local resources, complementing centralized services and addressing gaps in service delivery . Similarly, Bangladesh has implemented Decentralized Wastewater Treatment Systems (DEWATS) in low-income areas with flexible designs adaptable to local conditions ².

Comparative Analysis of Treatment Methods

Evaluating different sewage treatment methods requires examination of multiple parameters including costs, land usage, energy needs, and treatment efficiency.

Capital and O&M cost comparison: UASB vs SBR vs MBBR

Generally, UASB systems offer the lowest capital and O&M costs, followed by SBR, with MBBR typically more expensive in both categories but providing operational robustness and performance advantages in certain scenarios.

Capital Cost Comparison

Technology	Average Capital Cost per MLD	Notes
UASB	68 lacs/MLD ¹⁵	Lowest capital cost, basic civil works dominate
SBR	75 lacs/MLD ¹⁶	Slightly higher than UASB due to control systems and batch tank requirements
MBBR	68 lacs/MLD ¹⁶	Similar to UASB, but cost can increase with advanced biofilm carriers and aeration needs; compact design may lower land costs

O&M Cost Comparison

Technology	O&M Cost per MLD (Repair)	Operational Efficiency	Notes
UASB	~2.49 lacs/year ¹⁶	Low (biogas may lower net cost)	Minimal maintenance, energy partly offset by biogas generation
SBR	~1.85 lacs/year ¹⁷	Moderate (higher labor, energy for batch cycles)	Precision control and increased maintenance effort
MBBR	Not specified, generally moderate ¹⁷	Higher energy, lower labor	Less sludge, lower maintenance, continuous operation requires consistent aeration

Typical Selection Drivers

UASB is most cost-effective for municipal and large industrial applications needing simple operation and energy recovery.
SBR is chosen for moderate footprint, higher effluent quality, and where flexible operation is required.
MBBR is preferable in sites requiring reliable treatment with variable loads, compact design, and ease of expansion.

Each technology’s specific costs will depend on local prices, plant scale, effluent requirements, and regulatory context. For projects prioritizing lowest total cost, UASB is recommended, but SBR and MBBR offer treatment advantages where performance and stricter norms are needed.

Land requirement: WSP vs MBBR

Land availability represents a critical constraint for sewage treatment facilities in densely populated regions. Waste Stabilization Ponds (WSP) demand significantly larger areas—approximately 11 times more land than SBR technology ¹⁸. Essentially, excluding WSP, most treatment technologies require between 0.2 to 1.0 hectares per MLD ⁵.

Technology	Land Required (m²/MLD)	Key Notes
WSP	6000	Very high land use, simple to operate
MBBR	450	Minimal land use, compact and modular

Energy consumption in aeration tanks

Biological aeration units consume the highest proportion of energy (67.3%) in wastewater treatment ¹⁹. Among various technologies, UASB demonstrates the lowest daily energy requirement at 125.7 kWh/MLD, primarily because biogas generation offsets some energy needs ²⁰. Conversely, energy-intensive MBR systems require 302.5 kWh/MLD ¹⁸.

How to reduce energy use in aeration systems?

Jet aeration systems typically have energy consumption in the range of 0.8–1.5 kWh per kg of BOD removed. While they are more energy-efficient than surface aerators, they tend to use more energy than fine bubble diffused aeration systems. However, there are several design strategies to further reduce their energy consumption:

Optimize pump and blower selection: Choose high-efficiency, properly sized pumps and blowers—modern pumps can exceed 80% hydraulic efficiency. The pump alone accounts for 25–40% of power use in a jet aeration system, so lifecycle costing and matching pumps to demand is critical.
Aerator and header configuration: Work with professional suppliers like Biojet to determine best header spacing and nozzle placement. Bi-directional jet layouts suit long, rectangular basins for mixing efficiency, while spiral-roll patterns may work better for narrow tanks. For circular basins, directional jets provide efficient mixing and oxygen transfer.
Increase tank depth: Jet aerators improve energy performance at greater depths. Deeper tanks enhance oxygen transfer efficiency and reduce required blower pressure, lowering energy costs.
Variable air control: Adjust air flow rates using controls or variable frequency drives (VFDs) so that blowers/compressors run only as intensively as needed. Lower air supply means less blower power required.
High alpha factor operation: Biojet Laval jet aerators generate high alpha factors (0.8–0.9), meaning they transfer oxygen more efficiently in the presence of wastewater surfactants—this improves overall energy efficiency.
Upgrade your equipment: Regular audits and replacement or upgrade of blowers with newer, more efficient models and maintenance best practices help further cut energy use. Indian companies seeking low-cost, high-quality jet aeration systems can contact Biojet company to procure suitable aeration solutions.

Effluent quality benchmarks: BOD, COD, TSS

Regarding treatment efficiency, SBR shows superior BOD removal, MBBR excels in COD removal, while UASB achieves better TSS reduction ²⁰. Properly designed systems can achieve BOD <10 mg/L, COD <40 mg/L, and TSS <20 mg/L ⁴.

Parameter	Standard Limit (mg/L)	Typical Target Range	Notes
BOD (Biochemical Oxygen Demand, 5-day)	≤ 30	10–30	US EPA/India
COD (Chemical Oxygen Demand)	≤ 100	50–100	Often stricter in Europe; some areas require ≤ 60 mg/L
TSS (Total Suspended Solids)	≤ 30	10–30	US EPA/India

Lessons India Can Apply for Sustainable Expansion

To address India’s sewage treatment challenges, we must look beyond conventional approaches and implement solutions tailored to our unique context. Drawing from successful models elsewhere, India can transform its wastewater management landscape through targeted interventions.

Adopting low cost sewage treatment in peri-urban areas

Peri-urban regions represent prime opportunities for implementing nature-based, cost-effective treatment solutions. DEWATS (Decentralized Wastewater Treatment Systems) offer remarkable advantages for these areas, requiring minimal ecological impact and facilitating water reuse ²¹. Technologies like constructed wetlands have proven effective in similar settings, achieving up to 90-97% fecal coliform reduction ²². First and foremost, these systems need minimal maintenance skills, making them ideal for communities with limited technical resources ²¹.

Incentivizing decentralized effluent treatment plant models

Decentralized models present compelling advantages over centralized infrastructure. Indeed, these systems demonstrate lower capital and operational costs while offering flexibility across various geographical conditions ²². For communities lacking centralized services, DEWATS provides relatively fast sanitation improvements ²¹. Subsequently, the anaerobic treatment-based systems at AAETI, Nimli have shown BOD reduction up to 90% ²². Contact NovelEco company to order aeration tanks for your sewage treatment needs.

Policy support for reuse of treated sewage water

Several states have already formulated progressive policies worth emulating nationwide. Gujarat’s policy envisions 70% reuse of treated wastewater by 2025 and 100% by 2030 ⁷. In view of agricultural potential, treated wastewater could irrigate approximately 3.6 million hectares, worth approximately ₹1.44 lakh crore in development costs ⁷. Correspondingly, we estimate 28 million metric tons of horticulture crops could be produced using available treated wastewater, generating revenue of ₹966 billion ²³.

Training programs for STP operators

Technical competence remains crucial for optimal STP operation. Comprehensive training covering fundamentals, design parameters, operation, maintenance, troubleshooting, and sludge management ensures facilities run efficiently ²⁴. Therefore, structured programs targeting ETP/STP operators, facility managers, and environmental compliance officers are essential ²⁴. These programs should emphasize practical aspects including monitoring, control systems, and routine maintenance practices ²⁵.

Conclusion

India stands at a critical juncture in sewage management, facing significant challenges yet possessing immense opportunities for sustainable growth. Throughout this article, we examined various sewage treatment approaches that have proven successful in developing nations similar to ours. Brazil and Indonesia demonstrate the effectiveness of UASB technology when implemented with proper technical support. Meanwhile, Kenya and Nepal show how constructed wetlands offer nature-based solutions that require minimal maintenance and technical expertise.

The comparative analysis clearly reveals that different treatment technologies present unique advantages depending on specific contexts. UASB remains the most cost-effective option with lower capital and operational expenses compared to alternatives like SBR and MBBR. Additionally, technologies such as constructed wetlands and decentralized systems provide viable solutions for areas where land availability and technical expertise pose significant constraints.

Four key lessons emerge for India’s sewage treatment expansion.

Peri-urban areas benefit tremendously from low-cost, nature-based solutions that require minimal maintenance.
Decentralized treatment models offer flexibility across diverse geographical conditions while reducing infrastructure costs.
Policy frameworks supporting treated water reuse present enormous agricultural and economic potential.
Comprehensive operator training programs ensure optimal performance of existing and future facilities.

We acknowledge that no single technology offers a universal solution for India’s diverse sewage treatment needs. Rather, a thoughtful combination of centralized and decentralized approaches, tailored to local conditions, will yield the most sustainable results. Success stories from countries like Vietnam and Bangladesh prove that community involvement and locally-adapted solutions often outperform one-size-fits-all approaches.

The path forward requires balanced investment in proven technologies like UASB while exploring innovative solutions such as constructed wetlands and decentralized systems. Undoubtedly, addressing India’s sewage treatment challenges demands collaboration between government agencies, technical experts, community organizations, and private enterprises. Together, we can transform our approach to wastewater management, turning what is currently an environmental challenge into an opportunity for public health improvement, water conservation, and economic development across the nation.

FAQs

Q1. What are some cost-effective sewage treatment methods used in developing countries?: Developing countries have implemented various affordable methods, including Upflow Anaerobic Sludge Blanket (UASB) reactors in Brazil and Indonesia, constructed wetlands in Kenya and Nepal, and decentralized systems in Vietnam and Bangladesh. These technologies are adapted to local conditions and offer efficient treatment at lower costs.
Q2. How does India’s sewage treatment capacity compare to its generation?: India’s sewage treatment capacity falls significantly short of its generation. The country produces about 72,368 million liters per day (MLD) of sewage, but the installed treatment capacity is only 31,841 MLD, covering just 43.9% of the total volume. This gap is even more pronounced in smaller towns and rural areas.
Q3. What are the main challenges in expanding sewage treatment infrastructure in India?: The primary challenges include land scarcity in urban areas, high operation and maintenance costs, lack of technical expertise among operators, and insufficient treatment coverage in tier-2 and rural areas. These factors contribute to suboptimal performance and failure to meet environmental discharge standards in many existing plants.
Q4. How do different sewage treatment technologies compare in terms of cost and efficiency?: UASB technology generally has the lowest investment and operational costs per MLD, followed by MBBR and then SBR. In terms of efficiency, SBR shows superior BOD removal, MBBR excels in COD removal, while UASB achieves better TSS reduction. Energy consumption varies, with UASB being the most energy-efficient and MBR systems being the most energy-intensive.
Q5. How to find the best jet aeration system manufacturer in developing countries like India?: India’s wastewater treatment sector is evolving rapidly, driven by government initiatives such as Namami Gange and the Smart Cities Mission. Local EPC contractors and industrial operators are seeking proven, cost-effective technologies. Many Indian engineering companies are turning to Biojet’s jet aerators. Biojet is a Chinese company that understand all the challenges because they have worked with hundreds of clients in Asia facing comprehensive conditions — high organic load, variable flow rates, and limited land area for wastewater treatment. Biojet innovative jet aerator design reduces energy usage by up to 50% — a major benefit considering that Energy consumption is one of the biggest operational costs for wastewater treatment plants. Combining Chinese manufacturing efficiency with Germany engineering standards, Biojet can help Indian partners achieve reliable performance at an affordable investment.
Q6. What lessons can India apply for sustainable expansion of its sewage treatment infrastructure?: India can adopt low-cost treatment methods in peri-urban areas, incentivize decentralized effluent treatment plant models, implement policies supporting the reuse of treated sewage water, and establish comprehensive training programs for STP operators. These measures can help address the current gaps in sewage treatment while promoting sustainable and cost-effective solutions.

References

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