TECHNICAL PAPER
Crafting a simple, affordable system to treat brewery wastewater and avoid sewer surcharges
Sewer surcharges can significantly impact the bottom line for breweries and other food and beverage processors. Adding an onsite wastewater treatment plant is one way to reduce sewer surcharges, but many options are costly, complex, and require a significant amount of space, which can make it tough to decide whether to install a system or continue paying higher fees to the utility.
Bishop Water recently completed pilot testing of an easy-to-operate, compact system at an Ontario craft brewery to demonstrate its ability to reduce the contaminants that are discharged to the municipal sewer and potentially eliminate sewer surcharges.
A simple system for process solids and nutrients
The system combines two of our proven technologies, the Bishop Solids Management Solution and Bishop BioCord™ Reactors, to create a treatment train that can efficiently and affordably remove target contaminants like TSS, BOD, COD and adjust pH to the required discharge limits.
It’s a challenging task. The raw wastewater from the brewery that the pilot system was treating had a pH of 4.6, and average concentrations of COD and ammonia of 42,822 mg/L and 116 mg/L respectively.
Despite the high strength of this wastewater, we’ve designed the pilot system to operate with little operator oversight, low-energy consumption, few components and reliable performance. Here’s how it works:
- Raw wastewater is pumped to a mixing tank where a coagulant and flocculant are added to remove TSS and fine particles and pH is adjusted to the required range.
- Flocculated material is pumped to a Geotube geotextile dewatering bag, which retains the solids and releases clear, low-TSS filtrate.
- BioCord Reactors, an aerated, fixed-film biological treatment system, provides robust, low-energy removal of soluble BOD, COD and ammonia.
Our pilot system ran for about a year and consistently achieved a high level of contaminant removal, even though there were significant fluctuations in loading rates, which can be seen in the graph below.
The results showed the following:
- Average TSS removal efficiency of 99%
- Average COD removal efficiency of 72.59%
- pH consistently adjusted to 7.
We also noted that the BioCord system achieved simultaneous COD and ammonia removal, achieving average ammonia removal efficiency of about 36%. BioCord is capable of achieving greater than 90% ammonia, and although ammonia removal was not a target contaminant in this study, the rate could be improved by reducing the C:N ratio of the influent.
Although the pilot system was small, with a BioCord Reactor volume of only 120L, the system is easily scalable and customizable to handle larger flows and greater loading of TSS, COD and BOD from breweries or food processors. It also operates with fewer components, uses less electricity and requires less oversight and maintenance than alternative treatment technologies such as MBBR or MBR.
Although the pilot system was small, with a BioCord Reactor volume of only 120L, the system is easily scalable and customizable to handle larger flows and greater loading of TSS, COD and BOD from breweries or food processors. It also operates with fewer components, uses less electricity and requires less oversight and maintenance than alternative treatment technologies such as MBBR or MBR.
