Wastewater Treatment Solutions for Distilleries

The history of distilled beverages goes back to the middle ages. From 14th century Irish whiskeys to tech-driven distilleries of the 21st century, efficiency has increased over the centuries. However, water usage and wastewater produced have also increased. Distillers need efficient wastewater treatment solutions to minimize the risk of environmental pollution and reputational damage.

Why do you need Efficient Distillery Wastewater Treatment Solutions?

The distillery industry is one of the top industrial users of water. During fermentation, molasses with 76-90% solids are diluted in water and mixed with yeast culture in about a 10:1 ratio. This step produces fermented wash with 6-9% alcohol, distilled to attain 40% alcohol. The 40% alcohol stream is fed to the rectifier column to create a 95% rectified spirit. This process requires water for processing and cooling. And each step produces yeast sludge, spent lees, and spent wash as by-products and generates a high volume of wastewater with these contaminants. It also contains other dissolved solids, suspended solids, and organics, such as sugars, alcohol, and proteins. These contaminants influence pH, biological oxygen demand (BOD), and chemical oxygen demand (COD). Discharging untreated wastewater can pollute the environment, which is illegal. 

The UK’s code of practice defines owners and managers of distilleries as “waste holders.” As a waste-holder, you have a duty of care for wastewater and other by-products generated by your distillery. Local authorities also issue licenses, specifying distillers’ discharge limits. Non-compliance can lead to license revocation, hefty fines, or jail time. Whether you own or manage a distillery, efficient wastewater treatment can help you avoid legal challenges. 

Distillery Wastewater Treatment Systems

With yeast sludge, spent wash, spent lees, organics, and SS in your wastewater, you’ll need more than one treatment system to meet your discharge limits. The best strategy is to combine physical, chemical, and biological treatment processes. This wastewater treatment approach can reduce total dissolved solids (TDS), total suspended solids (TSS), FOG, BOD, and COD. You can use Biocell’s distillery containerized plants, pretreatment, sludge treatment, and DAF. 

Pretreatment of distillery wastewater

The first step in the wastewater treatment process should use mechanical screens to remove larger suspended solids. Efficient pretreatment can help protect distillery wastewater treatment systems in subsequent stages. But these screens vary in size from 1mm to 6mm and flowrate from 1l/sec to 500l/sec. When choosing pretreatment screens, focus on your daily wastewater flow and peak flow rate. 

Standard screw screens and coarse bar screens remove larger to medium-sized solids. Wastewater from distillery has sticky solids and requires pretreatment systems with drum screens. The best mechanical screen for your distillery should be customized to the size and type of solids in your wastewater. With Biocell’s compact screen units, you get an all-in-one solution for removing oil, grease, and solids like fibers and spent yeast grains. 

Containerized treatment plants for distillery wastewater 

Containerized wastewater treatment plants for distilleries combine primary settlement, secondary treatment, and clarification in a single container. First, wastewater goes through pretreatment to remove inorganic coarse materials and solids. The sludge goes for secondary treatment. Second, the biological treatment removes dissolved contaminants in your wastewater. It uses microorganisms to convert spent yeast and other dissolved solids into sludge and gases. Third, lamella separators built into the container enable clarification of the effluent. 

Advanced solutions like Biocell Containerized Wastewater Treatment come with tertiary treatment modules, such as chemical dosing, phosphorous reduction, and disinfection. Incorporating these treatments after the clarification process can help you meet stringent discharge limits. 

DAF for distilleries 

Dissolved air flotation (DAF) for distilleries removes solids, oil, and grease from wastewater. The DAF process uses micron-sized bubbles produced by in-built units, which dissolve air under pressure. These units release “white water” with micro-fine air bubbles. The bubbles attach to suspended yeast fibers, spent lees, and other solids and rise to the surface. Floated solids dewater and thicken on the surface, forming a layer of sludge. Traditional DAF systems use mechanical scrapers to remove the sludge and deposit it in another compartment for further treatment. 

Unlike traditional DAF systems, advanced solutions like Biocell DAF Containerized Plants are self-cleaning and automated. They have a cylindrical design, which eliminates dead zones. These containerized systems offer a chemical treatment, pH neutralization, and DAF reactor. With all these treatment solutions, you can remove suspended solids like yeast fibers in distillery wastewater and reduce carbon-oxygen demand by up to 90%. 

Distillery sludge treatment solutions

Distillery wastewater contains sludge with about 30% solid content, which comprises spent yeast and mineral matter. Spent yeast is highly biodegradable with a BOD of around 25000 mg/L. You can use DAF and secondary biological aerobic treatment to aggregate yeast sludge and produce concentrated liquid sludge with solids. Choose a treatment solution that combines sludge pressing and thickening systems. This combination can dewater all types of sludge from DAF and secondary biological treatment. 

Biocell’s Screw Press system has three dewatering zones, thickening, filtration, and compression. It separates solids from slurry liquid sludge in the thickening zone, filters all tiny particles, dries the sludge in the compression zone, and discharges dry sludge cake. With this three-in-one sludge treatment solution, you get treated water ready for discharge. You can reuse the water for cooling and sell dry yeast cake to cattle feed manufacturers. 

Conclusion 

Efficient wastewater treatment for your distillery can help you avoid non-compliance and legal issues. The best strategy to reduce yeast sludge, suspended solids, dissolved solids, organics, and other contaminants is to combine pretreatment, containerized plant, DAF, and sludge treatment. This approach delivers a highly efficient distillery wastewater treatment solution. It can help you meet your discharge limits, reuse water, and reduce wastage. To enjoy all these benefits, get your distillery wastewater treatment system from Biocell Water

Biocell provides high-quality and efficient wastewater treatment systems for distilleries. To learn more about Biocell wastewater treatment solutions, please fill out the form below.