Projects & Engineering Assessments

Brief received Combined effluent from dairy, confectionery, bakery, juice and carbonated-drink lines: 1,000 m³/day design flow with expansion planned, 24/7 operation (≈45 m³/h average). Peak COD 3,500–4,500 mg/L, BOD₅ 2,000–2,500 mg/L, BOD/COD ≈ 0.6. Discharge target: BOD < 30, TSS < 100, TDS < 2,100, oil & grease < 10 mg/L, pH 6–9.

What we asked first Whether high-TDS streams can be segregated at source, the peak factor per production line, and whether civil works (RC tanks) are local scope or ours.

Our position Segregated collection → screening → equalisation → pH correction → DAF → anaerobic → aerobic → solids separation → tertiary polishing. We advised against a single packaged unit at this scale and recommended comparing local RC tanks with supplied M&E against a multi-train modular approach.

For similar projects Above ~500 m³/day, packaged units stop being the cheapest option; the civil/equipment split decides the budget more than the process choice does.

Brief received ~150 m³/day (≈6 m³/h) of high-strength industrial effluent: COD 18,000–20,000 mg/L, BOD 12,000–14,000 mg/L, TSS 3,500–4,000 mg/L, TDS ~3,000 mg/L, NH₃-N ~800 mg/L, pH ~5. Ammonia removal load in the order of 100–110 kg N/day. Target NH₃-N < 50 mg/L; plant-wide COD < 250, BOD < 30, TSS < 100 mg/L.

What we asked first Whether the stripping tower is a stand-alone unit or part of a full ETP, the alkali available for pH lift, and how the recovered ammonia (ammonium sulphate or ammonia water) will be handled.

Our position Ammonia stripping tower with tail-gas absorption evaluated as a dedicated unit. We stated plainly that this unit alone cannot deliver the COD/BOD/TSS targets — those need the biological and physical stages of the full ETP.

For similar projects At NH₃-N above ~500 mg/L, stripping ahead of biology is not optional; but a stripping quote that promises full-plant compliance is a red flag.

Brief received A residential community of ~140 people at 250 L/person/day — ~35 m³/day of domestic sewage — needing a compact packaged station. Influent estimated as typical domestic sewage pending laboratory analysis.

What we asked first The discharge or reuse standard that applies (irrigation reuse changes the disinfection stage), the available footprint, and whether operation will be unattended.

Our position Two options priced side by side: an economical MBBR / contact-oxidation packaged plant, and a compact MBR for reuse-grade effluent.

For similar projects For communities under ~50 m³/day the process choice is driven by the reuse question, not by flow — decide what the water is for first.

Brief received An operating sewage treatment plant with an MBR stage of 35 m³/h needs its membrane modules replaced and capacity extended. Membrane-tank dimensions, aeration data and the existing module make were still to be provided.

What we asked first The existing module model and design flux, membrane-tank dimensions, air-scour blower capacity, and the permeate quality the plant must keep.

Our position Compatibility check first (module geometry, flux, permeate header), then module count and any rack modification — not a like-for-like part-number swap.

For similar projects Replacement membranes are a design task when the original module maker is no longer available: flux and air-scour must be re-verified, or the new modules foul within months.