Saturday, January 8, 2011

treatment wetlands and winery wastewaters

Wastewater of wineries are usually stored some months in tanks or ponds and periodically disposed on the farm’s fields or in the vineyards. This application has a dubious agronomic benefit, because great water amounts with low nutrient concentration (in terms of nitrogen and phosphorus which will be uptake by the crops) are spread. This practice is also typical for the wineries and wrongly considered as the only solution to the wastewaters management. 

The winery wastewater production is not regular during the year, and the production range from the end of the Summer to the end of Winter. During this period the application of wastewater to the fields is usually forbidden by the State regulations and by the European best management practices. It is hence necessary build up big tanks or accumulation basins to collect all the effluents produced and spread them in spring time.
Because of these the farmers must build up big tanks or accumulation basin to collect all the effluents product and spread it in Spring time.

To improve the winery management during the harvest and postharvest time, a possibility is to treat the effluents with the constructed wetlands.

Treatment wetland for winery wastewater in central Italy (one month after planting)

The winery produces two kind of wastewaters: waters from the washing of floors and open areas, and waters from the washing of machinery, bottles and storage tanks. Shepherd  (2001) refer a production of 3 litres of wastewaters for each litre of vine product. These waters are characterized by low pH value (5-6), high COD and BOD5 content (respectively 1000-45000 mg L-1 and 300-4000 mg L-1). The main organic loads are in the first time water flow. With these range inlet and flows values the CW has great potential in the treatment of this kind of polluted water. Masi (2000) and Shepherd (2001) reports large successful application of CW to treat the winery effluents, respectively in Italy and California.

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