Black liquor is formed as a by-product of the Kraft pulp and paper manufacture process. In
In the Kraft process, about half of the wood is dissolved, and together with the spent pulping
chemicals, forms a liquid called black liquor.
Black liquor spills from the process can subject a downstream wastewater treatment system to periods of upset conditions and could potentially push the total BOD loading beyond the aeration capacity leading to potential permit violations. While these accidental spills by nature are impossible to predict, being able to immediately identify a change in loading is critical to maintaining optimal performance of your (WWTS) wastewater treatment system.
The key goals of the study included:
(1) To quantify the impact of a black liquour spill on the microbial lectron transfer ( MET) output from the SENTRY platform
(2) Validate SENTRY as a real-time solution to detect black liquor spill events
Weak black liquor from a P&P mill was added directly to Tank A to simulate a black liquor spill entering the WWTS (control tank maintained normal flow rates and was not altered during the study).
Following the introduction of black liquor, the soluble COD increased, triggering an immediate alert response from the SENTRY monitoring platoform. The spike in COD and MET remained elevated before slowly returning to the “normal” baseline data that was observed throughout the duration of the study shown in red.
The quick response detected from the probes along with the real time viewing capabilities from the SENTRY monitoring platform provided an early warning of potential biological system imbalance.
This platform can allow operators and personnel to take immediate action to avoid BOD breakthrough to the effluent and limit any potential permit violations.