Ernteband Fruchtsaft in Germany produces fruit and vegetable concentrates, focusing particularly on apple, pear, carrot and beetroot. Wastewater flow fluctuates substantially through the year due to the seasonal nature of harvesting.
Following an in-depth investigation and discussions of options, the client decided to expand the existing plant by adding a high performance anaerobic treatment system.
The main requirements and constraints for the extension were:
- Very flexible system that compensates for the fluctuating inflow values
- Very little space available on site
- Installation and commissioning during operation of the existing aerobic system
- Low investment and operating costs
- De-sulphurisation of biogas not required
An ultra-high efficiency ANAFIT-R2S reactor with a very small footprint was built as a pretreatment step upstream of the existing activated sludge plant. The reactor is 2.85m in diameter and 24m high.
Post-extension operating figures:
- Treatment efficiency ANAFIT-R2S 85%
- Specific gas production 0.43m³/kg COD
- Aerobic stage treatment efficiency 90%
- Entire WWTP efficiency >98%
- Discharge COD <100mg/l
- Biogas to boiler house 500Nm³/d
- Energy production 3,750kWh/d
- Savings in natural gas 375m³/d
The benefits of the upgrade can be appraised by the following points:
- Wastewater discharge limits always met
- Expansion of the nearby sewage treatment plant avoided
- 80% reduction in sludge disposal costs
- Major reduction in load on activated sludge treatment
- 80% reduction in energy costs for aeration of the aerobic stage
- Savings of approximately 90,000Nm³/year of natural gas through the use of biogas in the company's own steam generator
References are available on request.