行业：环保行业

Monitoring scheme for toxic and hazardous gases in wastewater treatment plants

行业痛点

城镇 + 工业污水厂气体风险表现为”恶臭叠加 + 缺氧深井”双特征：进水段 H2S 突发可达 500-1000 ppm（致死浓度仅 100 ppm 30 分钟暴露）、生化段 NH3 长期 30-50 ppm 影响员工健康、污泥消化段 CH4 + H2S + CO2 三气并存（沼气含量 60-65% / 1000-3000 ppm / 35%）、污泥脱水机房粉尘 + NH3 + 嗜热细菌污染。员工进入格栅井 / 集水井 / 污泥井等受限空间事故多发（每年全国污水厂受限空间事故 50+ 起）。环保监管层面 HJ 1098-2020 恶臭排放标准对厂界 H2S < 0.06 ppm + NH3 < 1.5 ppm 严格管控，超标即被生态环境局处罚 + 限产整改。运营单位常因"事故性停产 + 应急喷淋 + 信访投诉"承受年损失数十万元。

方案概述

优锐安提供全工艺链 + 厂界恶臭联防联控方案：① **进水段**（粗格栅 / 提升泵房 / 沉砂池）：H2S + LEL + O2 + NH3 多组分固定监测 + 受限空间作业便携 4 合一；② **生化段**（AAO / 氧化沟 / SBR）：曝气池 NH3 + 溶解氧反馈 + H2S 边缘监测 + 厌氧区甲烷扩散监测；③ **污泥处理段**（消化池 / 脱水机房 / 污泥仓）：CH4 + H2S + CO2 三气固定监测 + 沼气罐压力 + 沼气含硫率（< 100 ppm 才能进锅炉）；④ **厂界恶臭联控**：8-12 个厂界恶臭监测站（H2S + NH3 + VOC + 风速风向 + PM2.5），实时溯源 + 自动算扩散范围；⑤ **中央监控平台**：所有数据汇聚 + 智能联动除臭设施（生物滤池风量 / 化学洗涤喷淋液配比）+ 短信报警 + 历史数据合规上报。

## Key Monitoring Node Configuration

### Water Inlet Section (Highest H2S Risk)

– Coarse grating well (underground depth of 8-12m): fixed H2S (range 0-500 ppm) + LEL + O2 + wind speed
– Sand trap: H2S + NH3
– Inlet water pump room: combustible gas LEL + oxygen deficiency O2
– Employees must undergo a mandatory 30-second confirmation using a portable 4-in-1 (O2 + LEL + H2S + CO) device before entering

### Biochemical Section

– AAO anaerobic zone: CH4 + H2S (methane produced through anaerobic reaction)
– Anoxic / Aerobic Zone: NH3 + Dissolved Oxygen (Aeration Feedback)
– Secondary sedimentation tank: NH3 + boundary odor sampling

### Sludge Treatment Section (Biogas Specialty)

– Sludge thickener: H2S + CH4
– Anaerobic digestion tank: fixed CH4 (range 0-100% LEL) + H2S (range 0-3000 ppm) + CO2 + gas storage tank level + pressure
– Inlet/outlet of biogas desulfurization tower: H2S online continuous monitoring (control desulfurizer dosing + verify desulfurization effect)
– Biogas boiler room: LEL × 25% to cut off the main gas supply valve + flame detector
– Sludge dewatering room: NH3 + dust

### Boundary odor (core of environmental compliance)

– 8-12 boundary monitoring stations: H2S (trigger at < 0.06 ppm) + NH3 (< 1.5 ppm) + VOC (PID 0-1000 ppb) + wind direction and speed - Automatic traceability: abnormal concentration + wind direction inversion → locate the leakage area → automatically notify the on-site team for investigation ## Key Technical Parameters - H2S electrochemical sensor range: 0-500 ppm (calibrated with standard gas every 6 months + components replaced every 12 months) - CH4 infrared principle (unaffected by H2S poisoning, a must-have for marsh gas scenarios) - Protection level: IP68 (high humidity in wastewater treatment plant + splash) - Explosion-proof grade Ex d IIB T4 (Zone 1 of marsh gas area) - Communication: 4G wireless + LoRa backup, data upload with < 30 seconds delay - The boundary station is powered by solar and wind energy, and is independently deployed (not reliant on the plant's power grid) ## Implementation Key 1. **Standard Operating Procedure (SOP) for Operations in Confined Spaces**: Conduct testing to ensure compliance → Perform forced ventilation for ≥ 15 minutes → Re-test → Attach safety ropes + have a guardian outside → Enter; Re-check must be conducted after 30 minutes 2. **Biogas desulfurization and boiler protection**: The H2S concentration at the outlet of the desulfurization tower must be less than 100 ppm before entering the biogas boiler, otherwise it will corrode the boiler and cause emissions to exceed standards 3. **Integrated odor removal and dosing**: When H2S concentration exceeds 30 ppm, automatically increase the dosage of NaOH in the chemical scrubber; when NH3 concentration exceeds 20 ppm, increase the dosage of H2SO4 4. **Environmental Compliance**: The odor concentration at the factory boundary is automatically reported to the local ecological environment bureau's monitoring platform, ensuring compliance with unannounced inspections 5. **Carbon Trading**: Biogas Utilization + Emission Reduction Data can be used as Application Materials for CCER Voluntary Emission Reduction Projects ## Regulatory Basis - GB 50014-2021 "Standard for Design of Outdoor Drainage" - CJJ 60-2011 "Technical Regulations for Operation, Maintenance, and Safety of Urban Sewage Treatment Plants" - HJ 1098-2020 "Emission Standards for Odor Pollutants from Wastewater Treatment Plants" - GB/T 14554-93 "Emission Standards for Odor Pollutants" - Chapter 11: Confined Spaces in GB 30871-2022 "Safety Code for Special Operations in Hazardous Chemical Enterprises" - GBZ 2.1-2019 Limit Values ## Applicable Customers Municipal wastewater plants (with a capacity of over 100,000 tons), wastewater treatment in industrial parks, village and town wastewater stations, reclaimed water plants, wastewater lift stations, landfill leachate treatment plants, sludge disposal centers, and self-built wastewater treatment in printing and dyeing/food/pharmaceutical industries.