Sugar is an essential product of human life and one of the most important substrates for the human diet. The sugar industry is primarily seasonal, operating only 150-210 days per year (November to May).
During the sugar manufacturing process, a significant amount of wastewater is generated, which contains a high amount of pollution load, particularly in terms of suspended solids, organic matter, press mud, bagasse, and air pollutants.
Let’s see the effect of water pollution caused by sugar manufacturing industries in India, and their effective treatment.
Production of wastewater in sugar manufacturing industries
Water used for cleaning purposes in various sections of the factory generates wastewater in the sugar industry.
There are no single units that generate wastewater, but wastewater is produced primarily by washing on the milling house floor, boiling house equipment such as evaporators, clarifiers, vacuum pans, centrifugation, and so on.
Furthermore, the periodic cleaning of lime water and SO2-producing houses, as well as the periodic descaling of heat exchangers and evaporators, using NaOH, Na2CO3, and HCl for heater descaling and neutralization, contribute to the massive volume of wastewater.
Effects of wastewater produced by the sugar manufacturing industry
Untreated industrial effluent discharges have long been known to have negative consequences.
Untreated melanoidins containing spent wash, in particular, can block sunlight from entering water bodies, resulting in lower photosynthetic activity and oxygen concentrations, which inhibit aquatic life survival.
Furthermore, untreated spent wash can reduce dissolved oxygen concentrations in water bodies and soil alkalinity, which inhibits seed germination in contaminated areas. As a result, direct discharge of such spent wash into bodies of water may result in the eutrophication, of contaminated water sources.
How to reduce water pollution caused by sugar manufacturing industries?
Sugar industry pollution, like pollution in other industries, can be reduced by improving water and material consumption within the factory. The sugar industry generates a large amount of wastewater, which can be reused or discharged as effluent, into water bodies after careful water treatment.
Water handling in various facilities, as well as recycling as much as possible, will significantly reduce waste. You can cut down on factory waste by recycling water.
Dry cleaning floors and floor cleaning with a controlled amount of water, also helps to reduce waste. Organic waste pollution can only be reduced through proper operational management. When the evaporator and vacuum pan are filled up and a large amount of syrup boils, sugar is lost from the condenser water, increasing the amount and strength of the wastewater.
Standard treatments of sugar industry effluent
Traditional wastewater treatment systems use activated sludge processes (ASPs), from various sugar mill units.Bar screens, skimmers, levelling tanks, aeration units, purifiers, and sludge drying floors, are examples of various units.
Other treatment methods include:
1. Technology for anaerobic lagoons.
2. Anaerobic Digestion.
3. Up-flow anaerobic sludge blanket reactor (UASB).
4. UBF (upward flow) sealing filter.
5. Aerobic biotransformation.
6. Solid membrane fixed bed reactor.
Anaerobic effluent treatment, using both lagoons and digesters, has been found to be more effective and cost-effective. An anaerobic lagoon with a detention time of 15 days and a loading of 0.38 kg BOD/m3d, can remove 89.6% of the BOD.
For Indian conditions, a two-stage biological treatment with anaerobic lagoons, followed by aerobic waste stabilization ponds is recommended where sufficient land is available. The use of fixed film techniques is also gaining popularity these days.
Sugar industry wastewater has complex characteristics and is considered a challenge for environmental engineers, in terms of treatment and utilization. The determination of physicochemical parameters prior to treatment and recyclingis an important mechanism.
Many different techniques are introduced and modified for the purpose, but their effectiveness is dependent on the water quality parameters.
How can we assist?
Netsol Water has aided in the resolution of hundreds of water-related problems, by utilizing a wide range of specialized water treatment and wastewater treatment technologies, in sugar manufacturing industries of India.