Chemical Industry Wastewater Treatment

Brief received The client-supplied design basis is 60 m³/d of sulphuric acid-containing acidic wastewater, but the stated flow may describe either the acid-recovery feed or the combined wastewater stream. No analytical results, operating hours, batch frequency, acid-recovery targets or reuse requirements are confirmed. A membrane suitability and sample-water assessment is therefore required before equipment selection.

What we asked first Please confirm the design flow and operating basis; provide complete water analyses including free sulphuric acid, pH, total acidity, sulphate salts, COD, oil, TSS and temperature; and define the recovered-acid and reuse requirements.

Our position The proposed solution comprises collection and equalisation, screening, oil separation and lamella clarification, followed by protection filtration and a diffusion dialysis system for sulphuric acid recovery. Dialysis water is prepared and supplied from a dedicated tank, while recovered acid is stored for reuse only after its concentration and impurity limits are verified. Residual liquor is transferred to the existing wastewater plant, and sludge and screenings require appropriate collection and dewatering. Final equipment sizing, membrane selection and any downstream treatment will change after the flow definition, analyses, operating pattern, reuse standard and client trial results are available.

For similar projects Prepare the wastewater characterisation, flow and operating data, recovered-acid specification, reuse assessment, site utilities and a representative sample for membrane compatibility and performance testing.

Brief received The client requires separate proposals based on feed flow and evaporation rate for a pilot MVR system treating sodium-containing LiCl solution. The client-supplied design basis includes salinity up to 200000 ppm and no reported organics, but lacks the full composition, ppm basis, feed conditions, concentration endpoint, crystal targets, utility data and trial requirements. Eight-hour daily operation may be considered subject to confirmation.

What we asked first Please confirm the complete Li⁺, Na⁺ and Cl⁻ composition and ppm basis; pH, temperature, density, viscosity, suspended solids, concentration endpoint, target salt, purity and moisture, mother-liquor and condensate destinations, utilities, trial method and material quantity, supply boundary and destination port.

Our position The proposed package uses guarded pre-treatment to remove entrained solids, followed by a falling-film MVR evaporator for low-temperature concentration under vacuum. Vapour is condensed in a clean circuit, while the concentrated liquor is cooled in a crystalliser. Solid-liquid separation by filtration or centrifugation, followed by washing, drying and sealed residue handling, produces a testable crystal fraction. Mother liquor is returned to a controlled tank for further concentration, with purge or disposal subject to composition and client requirements. Condensate is sampled before reuse or discharge. Both feed-flow and evaporation-rate cases will be costed independently. Final metallurgy, materials, heat-transfer area, energy estimates and performance require confirmed laboratory data and operating hours.

For similar projects Prepare representative feed and concentrate samples, solvent and salt analysis, utility availability, batch duration, recovery targets, residue handling requirements and acceptance criteria before final engineering design.

Brief received The client-supplied design basis is 40 m³/d for an eight-to-ten-hour operating day at a two-bay heavy equipment wash area serving crushing and concrete plant vehicles. Influent is reported to contain high suspended solids, cement fines, aggregate, and pH 11–12. Reuse for equipment washing and dust suppression requires pH 7–8, while other water-quality limits remain to be confirmed.

What we asked first Please confirm maximum vehicle dimensions and bay clearances, simultaneous operation, brush and automation requirements, electrical supply, drainage and reuse connections, peak discharge, TSS, particle size, alkalinity, oil and grease, neutralisation trials, and final reuse limits.

Our position The proposed system combines a rotary mechanical screen, grit separation, equalisation, automatic chemical dosing, lamella clarification, filtration, disinfection, and clean-water storage with reuse pumping. Screening and grit removal protect downstream equipment; equalisation stabilises batch discharges; coagulant and polymer dosing assist cement solids separation. Controlled acid dosing adjusts the reported alkaline influent before clarification, with final pH correction after filtration. Clarified water is filtered and disinfected before storage and reuse. Settled sludge is thickened and dewatered by a plate-and-frame filter press, with filtrate returned to equalisation. Final equipment, detention times, dosing rates, filtration selection, and reuse criteria will be confirmed after the client provides operating and water-quality data.

For similar projects Prepare vehicle dimensions, bay layouts, simultaneous-use assumptions, water analysis, neutralisation test results, peak-flow data, drainage and reuse conditions, electrical details, and acceptance criteria before final process sizing and equipment selection.