The confectionery manufacturer, located in Virginia, was faced with having to establish on-site wastewater pretreatment at its facility. A planned expansion and an overloaded publicly owned treatment works (POTW) led local authorities to require wastewater pretreatment in order to meet discharge limits of 250 mg/l for both biochemical oxygen demand (BOD) and total suspended solids (TSS). The raw wastewater characteristics were 10,000 mg/l chemical oxygen demand (COD); 5,000 mg/l BOD; and 1,500 mg/l TSS.
After investigating on-site aerobic and anaerobic treatment options, the confectionery manufacturer selected ADI Systems for the solution. Anaerobic treatment with aerobic polishing was chosen for many reasons including capital and operating costs, reliable odor control, and ADI Systems’ success with this type of technology.
The treatment train consists of a 1.0 MG (3,800 m3) ADI-BVF® anaerobic reactor, a 200,000 gal (760 m3) aeration tank, and a 21 ft (6.4 m) diameter tank clarifier. The BVF® reactor and the aeration tank are constructed of precast, post-tensioned concrete.
ADI Systems provided a complete design/build package for the project which included process design, detailed design, supply and installation of the system (reactor tank and cover, internals, piping, recycle pumps, and biogas handling equipment), process start-up (including training and process operating manual) and one year of follow-up.
Several years later, production at the confectionery plant increased yet again, at which point ADI Systems added treatment capacity to handle 24% more flow and load. A 130,000 gal (492 m3) equalization tank, a new fine bubble diffused aeration system and blowers, plus larger capacity internal BVF reactor settlers were installed as part of the upgrade.
The original wastewater treatment solution ADI Systems provided allowed the confectionery plant to meet discharge limits so it could expand its operations as planned, as well as increase production again years later. The project had a tight schedule, but work was successfully completed within six months.
The later upgrade was also completed on time and within budget. With the help of ADI Systems’ knowledgeable staff and reliable technologies, this confectionery manufacturer continues to consistently meet its discharge limits while manufacturing first-class confectionery products.
