How to treat waste water in Distillery Industry?
Distilleries are high-polluting industries that produce large amounts of wastewater known as spent wash. Pollutant and color removal from distillery effluent is becoming increasingly important, as this effluent causes extensive soil and water pollution due to high BOD and COD content and the presence of materials like phenolic compounds, which are toxic.
The pH of distillery wastewater can also be extremely low. Distilleries produce wastewater at several stages of the process, including distillation, condenser cooling, fermenter cooling, fermentation, and washing. The majority of this effluent is produced during the distillation and condenser cooling stages. The characteristics of the wastewater produced are determined by the feedstock used.
What are distilleries?
Distilleries are agro-based industries that use agricultural products such as sugar cane juice, sugar cane molasses, sugar beet molasses, corn, wheat, cassava, rice, and barley as raw materials. Because of the large volume of effluent and the presence of certain recalcitrant compounds, treating this stream by conventional methods is difficult.
Wastewater Produced by Distillery Industry
Distillery effluent has a dark brown color, an acidic pH, a high temperature, low dissolved oxygen (DO), a high biochemical oxygen demand (BOD), and a high chemical oxygen demand (COD) (COD). The pH of raw distillery wastewater is 4.0–4.6, the chemical oxygen demand is 85,000–110,000 ppm, the total dissolved solids are 85,000–110,000 ppm, and the biological oxygen demand is 25,000–35,000 ppm. Significant amounts of phenols (7,202 mg/L), chlorides (7,997 mg/L), sulphates (1,100 mg/L), nitrates, phosphates (1,625 mg/L), and heavy metals are also present in distillery effluent.
Water is essential in the distillery industry. It is used at every stage of the manufacturing process, including cleaning and washing, disinfection, heating and cooling. Water requirements are substantial, and reuse is frequently feasible by implementing ultrafiltration and reverse osmosis steps.
According to their origin and composition, the three major categories are:
1.Processing water is formed in special coolers and condensers, as well as evaporation condensates. In general, processing waters are free of pollutants and can be reused or discharged alongside stormwater after minimal pretreatment. Water reuse is possible; common applications include hot water and steam generation, as well as membrane cleaning.
2.Cleaning wastewater is typically generated by washing equipment that comes into direct contact with distilled products. Product spillage, pressing and CIP effluents, equipment malfunction, and even operational errors are all included. These effluents are plentiful and highly polluted, necessitating additional treatment.
3.Sanitary wastewater is found in lavatories, shower rooms, and other public restrooms. Sanitary wastewater is similar to municipal wastewater in composition and is typically piped directly to sewage treatment plants, but it can be used as a nitrogen source for unbalanced dairy effluents prior to secondary aerobic treatment.