Soil distribution of winery effluents and wwtp sludges: an eco-efficient alternative for their treatment

Abstract

The aim at this review is to assess the state of the art relative to the principles and methods of the winery effluents and sludges distribution; its technical description and limitations; soils and cultures adapted; aspects to be considered, and finally the Portuguese legislation in this subject (its major gaps are listed).

The distribution of winery effluents and sludges is a simple, low cost and technologically interesting alternative for treating these type of residues. This method is widely used in France, Australia, South Africa and USA. Its even preferred to other treatments because its less expensive and simple compared with others more complex and demanding specific work labour. Simultaneously is a good agronomic practice that, if correctly used, can contribute to water content and soil nutrient status. There is also the potential for control of various pests and diseases due to the phytochemical composition of the effluents. This practice is suitable in terms of current environmental concerns, because the liquid residues have an agricultural use and are recycled, supplying water and other benefits to the soil.

In Portugal this process is rarely used, and there is even a lack on legislation in relation to this matter. It is essential that legislation is agreed concerning the use of these effluents with respect to the treatment time of the year, volumes, and application conditions in relation to the soil type.