We found out that the COD range to be between 1800 mg/l to 5000 mg/l in the effluents from today's parboiling rice mills.
BOD range found in the effluent is from 400 ppm to as high as 2200 ppm in some cases.
Pollutant load in Puffed Rice Mill effluent is much lower due to the process itself and thus it is much easier to treat and reuse.
Typical effluent character of Puffed Rice Mill
Parameters | Results |
pH | 3.5 - 6.2 |
Turbidity (NTU) | 50- 100 |
COD ( mg/l ) | 800 -1500 |
BOD (mg / l ) | 300-1200 |
TSS (mg /l ) | 200 - 900 |
Typical effluent character of Parboiling Rice Mill
Think about the amount of water we can save in a month, or further - in a year and further in ten years !
If one takes an average of 1 Lt. of water requirement for 1 Kg. of paddy to be parboiled, then one can imagine that how many people will benefit from the reuse of water from a parboiling rice mill !
Parameters | Results |
pH | 3.5 - 6.2 |
Turbidity (NTU) | 145 - 250 |
COD ( mg/l ) | 3000 -4500 |
BOD (mg / l ) | 800-2200 |
TSS (mg /l ) | 700 - 1500 |
Flagship India believes the time has come to find innovative ways to use surface water resources along with recycling and reuse of effluent water in Parboiling and Puffed Rice Milling industries and other similar wet milling industries, for sustainable growth .
Rice mill effluent does not contain toxic compounds or pathogenic bacteria, but it can contain the traces of pesticide overuse, more so in the third world countries.
Discharge into soil or water bodies on a continuous basis causes major environmental problems.
The stagnant water emits repulsive odour.
This odour during soaking can be generated due to fermentative changes.
The growth of natural flora is effected due to the discharge of effluent into the soil.
Since it is rich in nutrients it triggers the growth of algae in water bodies.
Further eutrophication leads to low dissolved oxygen content and poor water quality with high BOD (Biological Oxygen Demand).
Due to the colour and turbidity of the waste-water, low penetration of sunlight into waterways affects photosynthesis processes of the residential flora.
In cases of use of this water to irrigate rice fields this in turn destroys the beneficial algae and the microbial population who are either residential or dependent on those flora.