When processing foods such as fruits, vegetables or potatoes, a lot of water is used, which is needed for washing and for further processing. Depending on this, there are different kinds of dirty water which are contaminated e.g. with plant residues, shell and root pieces, soil and sand particles or/and starch. Depending on the application, the dirty water is cleaned to such an extent that it can be returned to the environment or sewage system and/or reused in the washing or processing process.
The listed factors show how individual and complex the requirements for the water treatment technology for food water are. We would like to work with you to develop the optimal and economical solution for the treatment of your dirty water. In doing so, we draw on many years of experience in the treatment of water and wastewater. With our technologies we offer a wide range of options, from individual components to complete turnkey plants.
Our products are available to rent for pilot tests. Due to our extensive rental park, we can put together complete test systems individually for your task.
In a brewery the effluent is treated by a company’s own treatment-system. Due to an increase in production, causing the amount of effluent to increase as well, it was necessary to upgrade the treatment plant. One decided not to extend the whole system, but to increase the efficiency of the treatment stage.
Functional descriptionFor this purpose, a lamella separator has been installed subsequent to the pre-treatment / denitrification. The lamella separator separates the majority of the sludge-load and the water can be led back into the deni-tank.
For the production of canned vegetables the amount of effluent and soiling varies a lot throughout the season. The high fluctuations led, beside the high wastewater costs, to problems in the municipal biological-effluent-plant.
In order to limit the pollution loads and decrease the peak loads a pre-separation was to be installed.
Chosen processes
1. Dewatering screw
2. Lamella separator
3. Biological treatment with sludge recirculation
With the dewatering screw coarse material (larger 1mm) gets exported and dewatered at the same time.
The lamella separator separates the finer dirt particles. The particles / sludge-flocs settle onto the lamellas, slide into the sludge funnel and get exported by a pump. The last purification step is a biological treatment process with aeration. The accruing sludge is led back into the lamella separator.
Technical Details
| Clarifying area | 100 m2 |
|---|---|
| Lamella spacing | 40 mm |
| Housing / lamella material | coated steel / polypropylene |
| Additional equipment | rabble rake, frost protection, mud cone |
Performance characteristics
| Vegetable output | 40.000 t/a (6 t/h) |
|---|---|
| Processing products | carrots, spinach, peas, beans, cauliflower, onions, Brussels sprout |
| Rate of the pre-treatment system | 75 m3/h |
| Max. influent concentration | 20,000-40,000 mg/l CSB |
| Required discharge concentration | max. 2,000 mg/l CSB |
Due to this process the required effluent values could be met reliably. As for example the for the production of carrots, the CSB-value was reduced from 16.000 to 1.300 mg/l. Leiblein GmbH delivered the lamella separator for the process.
During the production of high-quality delicatessen like: salads, steaks, shashlik, roast sausages as well as fine desserts, effluent of different compositions occurs from the band washing machine. The effluent has high COD/BOD values, which cause high effluent costs and can cause deposits in the canalisation.
The objective was to design a effluent-treatment-system which reduces the high contamination loads, works reliably, can be set up in a confined area and is still reasonably priced. Thanks to the many years of experience, Leiblein GmbH succeeded to meet all requirements in an outstanding manner.
The effluent from the band washing machine is collected in a pump receiver and pumped into a buffer tank. A compressed air diaphragm pump delivers the reactor vessel with a constant effluent flow of for example: 300l/h. Precipitant and flocculant is added creating an easily filterable flock. The processed water is filtered in an inclined filter. The sludge is stripped of and led into a container. The filtrate flows into the canalisation.
Washing water from the sugar beet processing is loaded with soil and has to be treated. The standard method is to treat the water in a biogas reactor.
The company decided to use a Leiblein lamella separator for the recirculation of the sludge.
The lamella separator offers following advantages:
Functional description of the lamella separator:
The effluent from the biogas reactor flows, without the use of pumps, into the lamella separator system. Here, the effluent is led into the different lamella sections by a distribution system.
A potato peeling company was faced with problems with their wastewater, as high starch loads caused increasing disposal costs. Through a new process it is possible to separate the starch load cost-effective and to reduce the wastewater-costs significantly.
As the separation is carried out without adding any chemicals, the thickened starch-sludge can also be sold to the animal-feed industry.
At first coarse particles are removed by a coarse screen. The effluent is then led into a storage container from where a constant stream flows into the lamella separator. The particles are separated by inclined lamellar honeycomb filters. The particles accumulate to sludge in the sludge funnel at the bottom of the lamella separator. The sludge can easily be removed or pumped off.
The functionality was proven during long-term tests. In one test, the amount of settleable particles was even reduced from an average of 9,7 ml/l to 0,1 ml/l. In another test from 61,5 ml/l to 0,5 ml/l.
The concentration values of the sludge discharge to be reached were ca. 400-600 ml/l. Depending on the further use of the sludge, different processes for the after-treatment can be chosen.
In this case good separation results were reached with a clarifying area load of approx. 0,4 m/h.
| Clarifying area lamella separator | 19 m2 |
|---|---|
| Throughput | 8 m3/h |
| Settleable particles | 9,8 ml/l |
| Remaining settleable particles in the outlet | < 0,1 ml/l |
At a throughput of 8 m³/h and a clarifying area of 19 m² a clarifying area load of 0,42 m/h is reached. The amount of settleable particles in the outlet was around 400-600 ml/l.
Implementing
2000
