Intelligent Sludge Discharge at Shanghai Bailonggang WWTP

A mega-project of this scale places extreme demands on water quality data — accuracy and stability must hold over decades of operation. The wastewater treatment works required continuous online monitoring of oil content in water: a demanding measurement that has to run unattended in a harsh coastal desert environment, resist fouling, and integrate cleanly into plant process control.

Membrane performance calibration demands precise, time-aligned and traceable water-quality data to verify retention, anti-fouling and cleaning-recovery behavior. The pain points were acute: micro-leakage is hard to detect, and instrument drift under variable operating conditions contaminates the baseline data that the whole evaluation depends on.

Accurate sludge-blanket level measurement in the secondary clarifiers is the key to controlling scraper start/stop, saving energy and keeping effluent compliant — but the plant faced the industry's common pain points: strong water disturbance, sludge fouling on probes and a blurry mud-water boundary made the actual blanket thickness hard to determine, while conventional ultrasonic meters were severely disturbed by scum and bubbles, producing drifting data that could not be used as a basis for automatic control.