Caramel Colour Production Wastewater Treatment: Ammonia Process, Sugar and Deep Colour
Caramel colour is made by heating sugar with a catalyst, and the water it sends out carries the marks of that reaction. The ammonium sulphite process adds nitrogen and sulfur compounds to the stream. The unreacted sugar gives it a high organic load. The product itself gives it a deep brown colour that survives everything except oxidation and adsorption. The effluent is coloured, ammoniacal and loaded with dissolved carbon, and the design that works strips the ammonia early, breaks the colour with oxidation, and treats the sugar as the strong, easy carbon it is.
What the Stream Carries
The reaction and its wash circuits produce water rich in unreacted sugar, ammonium compounds from the sulphite process, and the colour compounds from the browning reactions.
Filtration and finishing water carries the fine product fraction, which is dense, which settles, and which is worth recovering because it is still product material.
Evaporator and dryer scrubber water is warm and dilute, and its volume is what the equalisation tank is sized against. Plants dealing with comparable loads face many of the same trade-offs covered in Latex Glove Dipping Wastewater Treatment.
Floor and equipment washing adds volume rather than load, and its contribution is the hydraulic design of the whole plant. Plants dealing with comparable loads face many of the same trade-offs covered in Wind Turbine Blade Manufacturing effluent.
The ammonium fraction is stripped before anything else. An air or steam strip lifts the ammonia out, and the recovered ammonia returns to the process where the plant's layout allows it.
The stripping step is where the consent exposure is removed. Ammonia that reaches the clarifier does not precipitate, and plants that skip the strip watch their nitrogen results climb. Much of this mirrors the situation set out in Optical Lens Grinding Wastewater Treatment system.
The stripped water then goes to the oxidation step with its nitrogen load gone, and the treatment plant is then sized for what remains.
Colour Removal
The deep brown colour survives biology and it survives ordinary coagulation. Where the discharge consent sets a colour limit, the polishing step is oxidation followed by coagulation and filtration.
Oxidant choice is jar-tested against the actual effluent. The colour in this industry is a reaction product, and it responds differently to different oxidants.
The polishing unit is small, because the oxidation step is doing the heavy work. It is sized on colour and occasional solids carryover, not on the main organic load.
Sugar and Biology
The unreacted sugar is the easiest carbon a treatment plant will ever eat, and anaerobic treatment takes it efficiently where volumes justify it. The biogas offsets the fuel that the evaporator already burns all day.
The aerobic stage behind it is sized modestly, and it handles the residual carbon comfortably. The nutrient balance is a design line item, because sugar water is carbon-rich and nutrient-poor.
Measured Results from Plants We Built
We commissioned a 60 m³/day plant for this duty in Foshan, Guangdong back in 2021. Feed COD came in around 2,000 mg/L and left at 90 mg/L — 95.5% removal.
A second unit of the same class, delivered in Hong'an, Hubei during 2021, ran 150 m³/day at 1,961 mg/L feed COD down to 200 mg/L.
| Location | Year | Flow | Feed COD | Treated COD | Removal |
|---|---|---|---|---|---|
| Foshan, Guangdong | 2021 | 60 m³/d | 2,000 mg/L | 90 mg/L | 95.5% |
| Hong'an, Hubei | 2021 | 150 m³/d | 1,961 mg/L | 200 mg/L | 89.8% |
Figures are site-measured values from commissioned plants, not modelled estimates.
Where the plant has no anaerobic stage, extended aeration handles the full stream, at the cost of a larger basin and a larger power bill.
Operating Notes
Strip the ammonia before the oxidation step. Nitrogen that reaches the clarifier does not precipitate.
Jar-test the oxidant against the real effluent. Caramel colour is not one problem; it is a different problem for every plant.
Dose the nutrients. Sugar water without nitrogen and phosphorus starves the biology that is supposed to eat it.
Where This Fits in the Wider Plant
The process logic sits close to what is described in Antimony Smelting Wastewater Treatment, particularly on the pretreatment side. Most facilities do not run a single clean stream, and a shared equalisation and biological stage is usually the economical answer once the streams are chemically compatible.
Why Choose Baihuipu as Your Manufacturer
Picking a supplier for this kind of plant is mostly about who carries the risk when something goes wrong. We have built this equipment for more than twenty years, and we are the ones who fabricated it, programmed the controls and will still answer the phone three years from now.
Manufacturing Base in Guangdong
Owned production lines mean we control tolerances, materials and delivery. Standard modular units and bespoke skids are both built by our own people, so schedule commitments are ours to keep.
Two Decades of Field Data
Food and beverage, chemicals, electroplating, textile dyeing, mining, municipal work — we have commissioned across all of them. The useful part is not the project count, it is having seen how plants fail in year seven and designing those failures out.
Complete System Responsibility
One supplier, one process guarantee. We take the plant from preliminary screening through to membrane separation, evaporation and brine management, with process, mechanical, electrical and controls engineering handled internally.
After the Handover
Spares for everything we install are held in stock. Remote telemetry is available on most systems, and our service engineers commission, train your operators and turn out for emergencies.
Getting Started
Send us a water analysis and your production profile and we will tell you honestly what the process should look like and roughly what it costs to build and run. Reach our engineering team on WhatsApp: +86 13631765076 or via hkbhp.com.
WhatsApp: +86 13631765076
Frequently Asked Questions
Which discharge standard will the treated water meet?
We design against whatever consent applies at your boundary — GB 8978, local sewer limits, or a ZLD target with no liquid discharge at all. The design basis is agreed in writing before fabrication, so there is no argument later about what "compliant" meant.
Do you handle installation and operator training?
Every unit we supply is commissioned by our own engineers. Training happens on site with your actual operators, and the O&M manual covers routine work plus troubleshooting. Remote diagnostics through the control system are included for the first year.
Can you work with our existing equipment?
Often yes. We regularly integrate into existing civil structures where the concrete is sound, replacing internals and controls rather than starting over. We will tell you honestly when legacy kit is beyond economic repair.
How do you handle sludge from this process?
Sludge handling is where most budgets quietly blow out. We size dewatering against realistic solids production, and we usually recommend a filter press for this duty. The disposal route — landfill, incineration, or a licensed contractor — should be confirmed before commissioning.
