Landfill Odor Monitoring Solution: Nexisense Professional Guide

Odor pollution has become one of the most visible environmental issues affecting residents' quality of life. Landfills, waste transfer stations, food waste treatment facilities, wastewater treatment plants, and slaughterhouses generate complex odors due to anaerobic fermentation of organic matter and volatilization of leachate, including ammonia, hydrogen sulfide, methanethiol, amines, and indoles. These odors not only cause nuisance complaints but can trigger collective complaints and social conflicts. Traditional olfactory-based monitoring methods are subjective and inefficient, insufficient for automated, data-driven supervision. With years of environmental monitoring experience, Nexisense has developed the SGA-900 series online odor monitoring system (electronic nose), providing intelligent, standardized, and objective monitoring tools for odor sources. This article discusses odor causes, monitoring challenges, and introduces the technical features, deployment guidelines, and practical value of the Nexisense solution.

Causes of Odor Pollution and Monitoring Challenges

Landfill odors mainly arise from the anaerobic decomposition of proteins, fats, and carbohydrates. Typical compounds include:

• Ammonia (NH₃)

• Hydrogen sulfide (H₂S)

• Volatile sulfur compounds (methanethiol, dimethyl disulfide, etc.)

• Amines, indoles, skatoles

• Short-chain fatty acids

These compounds are low in concentration, diverse in type, and have widely varying odor thresholds. They are also affected by wind speed, wind direction, temperature, humidity, and atmospheric pressure, making it difficult for traditional single-gas sensors to accurately represent overall odor intensity. GB 14554-1993 uses odor concentration (OU/m³) as a comprehensive indicator, but manual sniffing methods are subjective and cannot provide continuous monitoring.

Environmental authorities increasingly require odor monitoring to provide:

• Continuous and automatic online monitoring

• Objective quantification of odor concentration (OU)

• Multi-parameter analysis

• Real-time data upload to environmental platforms

• Coverage of plant boundaries and sensitive points

The Nexisense SGA-900 series is an integrated solution developed to meet these requirements.

Nexisense SGA-900 Online Odor Monitoring System

The SGA-900-OU system uses patented pre-calibrated smart sensors and independent algorithms to provide a global odor concentration (OU) with a single sensor array, breaking foreign technology and cost dependency. The system integrates sampling, filtering, dehumidification, detection, data processing, display, transmission, and backup power. Key features include:

• Simultaneous monitoring of odor (OU) + up to five characteristic gases (NH₃, H₂S, methanethiol, etc.) + PM2.5, PM10, temperature, and humidity, totaling over ten parameters

• Industrial-grade high-precision touchscreen, displaying real-time, 1-minute/1-hour average, maximum/minimum values, and historical curve queries

• Large storage (>100,000 records), supports USB export, TCP/IP, Modbus RTU

• GPRS/4G wireless upload or wired networking, compatible with environmental platforms

• Outdoor nano-coated enclosure, resistant to sun, rain, dust, water, and insects for long-term deployment

• Open functions: baseline adjustment, zero correction, calibration gas, customizable alarm points, data correction

• Built-in backup battery to maintain monitoring for several hours during power outage

With a response time of 1 minute and typical measurement range of 10–10,000 OU/m³, the SGA-900 series covers plant boundaries and sensitive points in landfills, transfer stations, and wastewater treatment plants. Deployment has significantly reduced odor complaints and increased regulatory acceptance.

Portable and Modular Monitoring Solutions

For complaint inspections, mobile or temporary monitoring, the SGA-608 series offers portable odor monitoring systems, providing real-time odor concentration and characteristic gas data for field inspections and evidence collection.

For system integrators and manufacturers, the SGA-100 series and SGA-100X smart monitoring box offer standardized modules, plug-and-play, suitable for OEM integration into monitoring vehicles, drones, or small monitoring stations.

Deployment and Maintenance

Monitoring point selection is critical:

• Landfills: main disposal zones, around leachate tanks, near working areas

• Transfer stations: main working areas and downwind station boundaries

• Wastewater plants: aeration tanks, sludge dewatering areas, odor control facility entrances/exits

At least 3–4 points are recommended for enveloping coverage. Installation height: 1.5–2.5 m. Avoid obstructions and dust accumulation. Clean sampling lines and replace filters every 1–3 months. Remote parameter adjustments and firmware upgrades reduce onsite maintenance frequency.

Value in Environmental Management and Public Communication

Continuous, objective odor data provides strong evidence for regulatory authorities and a scientific basis for self-management. Comparing historical data evaluates deodorization efficiency and process adjustments. Combining odor concentration with wind data helps trace pollution sources. Some projects integrate automated alerts with complaint systems, enabling immediate response and mitigating conflicts.

In the context of “zero-waste city” initiatives and rising public environmental awareness, proactive online odor monitoring demonstrates social responsibility and facilitates policy support.

Comprehensive Odor Monitoring Solution

• SGA-900: fixed online monitoring system (core product)

• SGA-608: portable mobile monitoring system

• SGA-100: modules and smart box for integration

• Support: alarm controllers, multi-parameter expansion, cloud data platform, operation and maintenance services

Custom development options include specific odor factors, video integration, and drone interfaces. Nexisense provides full lifecycle services: site evaluation, solution design, installation, annual calibration, and maintenance.

Frequently Asked Questions (FAQ)

1. How to ensure representative data with variable wind?
Multiple points (≥3–4) combined with meteorological data allow wind rose analysis. SGA-900 samples every minute and averages hourly to reduce short-term weather effects.

2. Consistency of OU with human perception?
Patented pre-calibrated algorithm; deviation ±25% versus a 6-person panel in 10–5000 OU/m³ range, meeting GB 14554 objective monitoring requirements.

3. High humidity near aeration tanks affect sensors?
Internal dehumidification and hydrophobic filter protect sensors. Mean time between failures >2.5 years; check dehumidifier quarterly.

4. Using SGA-608 portable for complaint inspections?
Ready to use, provides data within 5 minutes. Compare upwind and downwind points for field verification and evidence.

5. Secure data upload to environmental platform?
GPRS/4G, compliant with HJ 212-2017 standard, encrypted, resumable, dual backup, integrity ≥99%.

6. Prevent sampling line blockage in enclosed, dusty transfer stations?
High-efficiency dust filter + automatic backflush; check lines every 1–2 months to prevent blockage.

7. Support integration with deodorization equipment?
Digital outputs and Modbus allow automatic activation of deodorization systems when odor concentration exceeds set value.

8. ROI evaluation?
Reduction in complaints (≥60%), avoid fines, improve corporate image, access green subsidies/policies. Typical payback 2–4 years.

Conclusion

Odor issues at landfills and related facilities are key environmental governance and social stability concerns. Nexisense SGA-900 series, with patented algorithms, multi-parameter monitoring, reliable transmission, and open interfaces, provides continuous, objective, and cost-effective monitoring. Proactive online odor monitoring not only meets compliance but demonstrates social responsibility and facilitates conflict management and operational opportunities. For site surveys, pilot deployments, or custom solutions, the professional Nexisense team is ready to assist.