An advisory engagement proposed a high-rate IC anaerobic reactor to cut paper-mill COD load and generate biogas before aerobic polishing.
A recycled-fibre mill's aerobic plant was overloaded by high-COD process water, with rising energy and sludge costs and limited headroom for production growth.
For pulp & paper operators, a challenge of this kind translates straight into cost and risk — higher chemical and energy use, lost capacity, a heavier maintenance burden and, ultimately, the threat of a discharge-consent breach. The reliable route is to measure the actual stream first, understand what is really driving the problem, and only then select and size the treatment. That diagnostic discipline is where Reynolds & Bauhm began this engagement.
Reynolds & Bauhm was engaged as the consulting engineer on this project. Working alongside the site team, we characterised the stream and proposed a solution sized to the measured duty rather than a catalogue specification. The recommended approach combined several coordinated measures:
Reynolds & Bauhm acted in an advisory capacity — assessing the problem and proposing and sizing the solution. This is a representative scenario showing how we approach a pulp & paper challenge of this type; figures are typical of the technology proposed, and every project is validated against your own data.
Each stage was selected against the stream analysis and sized with a sensible design margin, then set out as a process flow diagram and functional design specification for the client to take forward. Reynolds & Bauhm defined the duty, the equipment selection and the control philosophy, and identified the interface and performance risks to resolve before implementation. The proposal included a commissioning and validation plan — instrument calibration, control-loop tuning against live conditions, operator training and O&M documentation — so that, once built by the project team, the plant could meet its targets from start-up and stay there.
| Parameter | Before | After (target) |
|---|---|---|
| COD load to aerobic | 100% | 15% |
| Aeration energy | baseline | −55% |
| Biogas | none | recovered |
Beyond the headline figures, the proposed approach targets reliable, repeatable compliance and a measurable reduction in operating cost — the combination that justifies the investment and protects the site against tightening regulation.
The proposed train is built around a real stream analysis, not an assumption — the single biggest determinant of whether a pulp & paper plant succeeds.
Each stage earns its place against the measured load, avoiding both under-treatment and the cost of over-engineering.
A commissioning and validation plan means the result is provable and auditable, not just claimed.
The same engineering approach transfers to comparable pulp & paper sites with similar duties.
Reynolds & Bauhm can assess feasibility and propose a validated, sized solution for your pulp & paper application. Send us your flow, stream analysis and target consent and we will scope the treatment train, size it and set out the options.
Our expertise spans multiple industries with sector-specific water treatment solutions.