|Reduction in Wastewater Discharges at a Meat Processing Plant||Estonia||1993||Full scale|
MANUFACTURE OF FOOD PRODUCTS AND BEVERAGES # 16
Rakvere Meat Processing Plant, constructed in 1990, is a full line red meat plant processing pork, beef and some lamb; Plant operations include:
The plant has an average daily production capacity of 42 tons of sausage products and 17 tons of semi-manufactured products. Annual value of all products is about $25 million. The plant employs about 950 persons.
At Rakvere, processing of cattle stomachs to recover salable products such as tripe requires extensive handling and cleaning of stomachs which contain manure. In the past, the cattle stomachs underwent two washings after removal of manure. To increase the value of the product, a third wash step was added. The wastewater from all washing steps were sent to a manure press to concentrate solids before discharge to the wastewater treatment plant. The stomach cleaning and washing procedure was performed on a flat surface which increased the amount of handling and water required.
The cleaner production measures were initiated under World Environment Center's (WEC's) Industrial Waste Minimization Program in the Baltic countries.
Cleaner Production Principle:
Cleaner Production Application:
The wastewater discharge from the fat separation step
(known as "glue water") has a fat content ranging from 8 to 30 percent. In the
past, this wastewater was discharged to the wastewater treatment facility, contributing to
high biological oxygen demand (BOD) loadings.
During the waste minimization project, an evaluation was performed to identify opportunities to reuse wastewater streams with high BOD. Using a chemical oxygen demand (COD) analyzer, it was determined that the "glue water" stream had a high COD content and was a good candidate for recovery and reuse. A decision was made to install a pump to divert and recover the "glue water" for use by farmers as feed.
During the waste minimization project, an evaluation was performed to identify opportunities to reduce the volume of wastewater streams with high biological oxygen demand (BOD). Using a chemical oxygen demand (COD) analyzer, it was determined that the wash water from cattle stomach cleaning operations had a high COD content and was a good candidate for reduction. A decision was made to construct a "birdcage" on which cattle stomachs could be stretched during washing. This device facilitated handling, exposed more stomach area for cleaning, and reduced water use. In addition, screens were added to the wash drums to recover organic solids from the final two wash steps.
Many hoses were not equipped with shutoff nozzles and were left running when not in use. These practices resulted in excessive water use and high operating costs.
Timely repair of leaking nozzles and replacement of missing nozzles was ensured during cleaner production program..
Environmental and Economic Benefits:
The spectrophotometer DR2000 was supplied by HACH Chemical Company of Loveland, Colorado, United States. The United States Agency for International Development (USAID) paid $1,447 toward the cost and the company, $1,000. The actual equipment cost was $4,400. Since the equipment has been utilized in two other waste minimization projects, only one-third of the cost is assigned to this project. The change resulted in a savings per year of $11,600 with a payback period of less than three months.
As a result of the project, the facility reduced COD levels in its wastewater by 54 tons O2/year.
The facility reduced COD levels in its wastewater by 9 tons/year and reduced fresh water consumption.
Since the equipment has been utilized in two other waste minimization projects, only one-third of the cost is assigned to this project. This change resulted in a savings of $9,500 per year and a payback period of less than four months.
The facility reduced water usage by 316,800 m3/year.
Since the equipment has been utilized in two other waste minimization projects, only one-third of the cost is assigned to this project. This project resulted in a savings per year of $114,000 with a payback period of less than three weeks.
This case study was taken from the WEC publication "Economic and Environmental Benefits of Industrial Waste Minimization in Estonia, Latvia and Lithuania" (1995). It was edited for the UNEP IE ICPIC diskette in June 1997.
Subsequently, in September 1998 the case study underwent a technical review by Dr. Prasad Modak, Environmental Management Centre, Mumbai, India.