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Due to its high COD concentration, poor decomposition by microorganisms, and high viscosity, starch wastewater is one of the most difficult wastewater types to treat efficiently. After a long period of researching and developing, NGO has successfully applied starch wastewater treatment solution in some bakeries, which effectively treats the pollutants.

There are many kinds of starch such as wheat flour, cassava flour, sweet potato flour, potato flour. All of them are popular and important raw materials for many different manufacturing and processing industries, including food & spices production or bakeries. Some denatured starches are used in some industries such as paper and packaging production.

Starch wastewater generated from above-stated manufacturing activities is hard to treat effectively because the following reasons:

  • Very high COD concentration (>3000 mg/l)
  • Starch is difficult to be decomposed by microorganisms, it requires large treatment tanks and occupy large area.  If we do not have enough space for treatment tanks, the quality of after-treatment water shall not meet requirement of Ministry of Natural Resources and Environment.
  • When starch stays in the treatment tank for long time (for example, in balancing tanks, sedimentation tanks, filtered tanks), of which PH normally shall be changed and affects the pH of the whole wastewater.
  • Starch produces high viscosity in wastewater, which makes microbiological treatment and filtration at later stages more difficult, and the operation becomes more complicated, especially when the temperature changes.
  • Starch is difficult to get coagulated and sediment. Current systems can use PAC, Polymer to coagulate and sediment starch, thereby reducing COD concentration in wastewater for easier microbiological treatment in later stages. But after coagulating and sedimentation, the characteristics of wastewater such as the viscosity as well as the complex feature and the breaking difficulty of COD are hardly improved.

In order to effectively treat starch effluent, save investment cost as well as tank footprint, the effective collection of starch in wastewater from initial treatment phase is the most important factor.

NGO has implemented a series of experiments for several months with different responses and found out the solution and successfully applied starch collection solution in a short time of 7-45 minutes, depending on particular application process, meanwhile minimizing the viscosity of wastewater. Collected starch wastewater has COD concentration just equivalent to domestic wastewater, even much lower, so the treatment system becomes extremely simple, space saving, reducing excess sludge generated during microbiological reaction, thereby saving operating cost. Collected starch can also be reused for many purposes or removed together with excess sludge.

1. Starch wastewater treatment solution

Starch wastewater treatment solution

2. Demonstration of starch waste water treatment technology

Starch wastewater at collection tank shall be pumped into balancing tank. At this tank, screening will be used to remove coarse solids before discharging into the treatment tank to prevent clogging. Wastewater is pumped from balancing tank to starch collection tank to treat starch and reduce viscosity. Outlet water from starch-collection tank has significant low COD concentration which is just equivalent to normal domestic waste water. At aerobic tank, high microorganism density shall thoroughly remove pollutants such as ammonium, part of BOD, nitrate. Wastewater from aerobic tank shall be pumped into sedimentation tank before discharging into environment. Total retention time: ~24 hours.

After-treatment water meets A stardard or B stardarad - QCVN 40:2011/BTNMT for industrial wastewater.


If your business is interested in solution to inlet water treatment, or has a demand for ion exchange materials, please contact NGO via phone number (024) 3566 8225 or email office@8ngo.com for direct consultation.

Source: NGO