行业：市政工程

Monitoring Solution for Hydrogen Sulfide and Combustible Gases in Municipal Wastewater Treatment Plants

Fixed and portable dual coverage, integrated with SCADA exhaust linkage, ensuring zero accidents in confined space operations

行业痛点

市政污水处理厂是 H2S（硫化氢）+ CH4（甲烷）+ NH3（氨气）+ 缺氧四重风险叠加现场。进水泵房、粗格栅井、调节池厌氧段 H2S 浓度突发可达 500-1000 ppm（致死浓度仅 100 ppm 30 分钟），员工进出格栅井、清掏污泥井、消化池检修频发受限空间事故。沼气回用系统 CH4 浓度 60-65%（爆炸下限 5%），管道泄漏即可致毁灭性爆炸。曝气池、污泥脱水机房 NH3 + 粉尘 + 噪声形成复杂工况。传统单点检测仪覆盖不全、维护成本高、数据孤岛严重，运营单位每年合规罚款 + 事故损失数十万到上百万。

方案概述

优锐安提供”进水段 + 生化段 + 污泥消化段 + 出水段”全工艺链气体监测方案：固定式 H2S + LEL + O2 + NH3 + CO2 多组分监测网，覆盖粗格栅井 / 沉砂池 / 调节池 / AAO 池 / 二沉池 / 污泥消化罐 / 储气柜 / 沼气锅炉。关键设备：耐腐蚀防水探头（IP68，应对 H2S + 高湿环境）、抗 NH3 串扰的电化学传感器、便携式 4 合一受限空间检测仪（员工人手一台）、固定式 + 便携式 + 巡检系统三层防护。配套数字孪生工艺看板，与 SCADA / DCS 联动控制曝气量、风机变频、应急排风。布点密度按 GB 50014-2021 + CJJ 60-2011 标准，进水泵房 50m² 至少 1 套、消化池储气柜 30m² 至少 1 套。

## Key Monitoring Nodes

– **Intake lift pump room / coarse screen well**: H2S 0-500 ppm pre-alarm 10 ppm (PC-STEL) + LEL 25%
– **Biochemical treatment (AAO / oxidation ditch)**: NH3 + H2S dual-parameter + dissolved oxygen feedback in aeration tank
– **Sludge digestion system**: CH4 + H2S (biogas containing 1000-3000 ppm H2S, desulfurization required before reuse) + gas storage tank level + pressure interlock
– **Sludge Dewatering Room**: NH3 0-100 ppm + dust
– **Marsh gas boiler room**: LEL × 25% high alarm → automatic shut-off of main gas supply valve

## Confined Space Operations (Key Safety Control)

Employees must undergo a mandatory 30-second detection test using a portable 4-in-1 (O2 + LEL + H2S + CO) device before entering digestion tanks, biogas tanks, or underground well chambers. Only those who meet the standards are allowed to enter. Once inside, external monitoring, escape masks, and SCBA backups are required.

## Implementation Key Points

1. **The lifespan of the H2S sensor is short (high H2S concentration is prone to poisoning), and a service package is promised that includes 6 months of calibration and 12 months of replacement.**
2. The biogas main pipeline must be dual-metered (flow rate + concentration) to facilitate the calculation of carbon reduction and carbon trading
3. Interlock with PLC: H2S > 50 ppm → automatically activate emergency ventilation + close water inlet valve; LEL > 25% → immediately shut off the main biogas pipeline

## Regulatory Basis

– GB 50014-2021 “Standard for Design of Outdoor Drainage”
– CJJ 60-2011 “Technical Regulations for Operation, Maintenance, and Safety of Urban Wastewater Treatment Plants”
– HJ 1098-2020 Emission Standards for Odor Pollutants from Wastewater Treatment Plants
– GBZ 2.1-2019 H2S PC-TWA 10 mg/m³ / PC-STEL 15 mg/m³

## Applicable Customers

Municipal wastewater plants (with a capacity of over 10,000 tons), industrial park wastewater treatment, village and town wastewater stations, reclaimed water plants, and wastewater lift stations.