ZeoLIFE - Water pollution reduction and water saving using a natural zeolite cycle

Abstract:

Background

The Nitrates Directive (91/676/CEE) was adopted by the EU in 1991 to protect groundwater threatened by overexploitation of agricultural land and the accumulation of nitrates. In those areas where agriculture forms the basis of the local economy, the overexploitation of land gives rise to a series of problems linked to massive chemical fertilisation. The effect of rainfall causes nitrates to accumulate in groundwater and surface waters, thus leading to eutrophication, especially in inner and coastal lagoons and swamps. As a result, progressive desertification of agricultural lands occurs in the medium or long term,. The fertilising power of zeolites, however, is not affected by rain washing. Thus, zeolites could slow the process of exhaustion of agricultural soil and counteract the agricultural problems caused by climate change, growing consumption and the introduction of new crops, such as those used for biofuel.

Objectives

The ZeoLIFE project aims to test an innovative integrated zeolitic cycle that reduces the nitrogen content in livestock effluents and agricultural soils, and improves the yield and economisation of irrigation water and fertilisers, thus reducing pollution of fresh water and groundwater pollution and overexploitation of water resources. More than 50% of natural zeolitic rocks consists of zeolites, a group of minerals with special physical and chemical properties, such as high and selective cation exchange capacity (CEC), molecular adsorption and reversible dehydration. Zeolites can uptake ammonium (NH4), which is found in fertilisers, and release it at a slow enough rate that it can be absorbed by the roots of plants.

Specific objectives of the project are:
◦The protection of fresh water and groundwater from nitrate pollution produced by the agronomic industry;
◦The reduction of water and soil pollution produced by point (cattle breeding) and diffuse (agriculture) sources of nitrates;
◦The qualitative and quantitative preservation of the water resource;
◦The reduction and prevention of seawater pollution;
◦The optimisation of the use of water in agriculture and reduced use of chemical fertilisers;
◦The improvement of agricultural soil characteristics; and
◦The trial of a feasible way to combat desertification and agricultural soil exhaustion.

Expected results: The project is expected to:
◦Reduce groundwater and surface water nitrate pollution, because of the reduction of chemical fertilisation in agriculture and of NH4 content of manure;
◦Decrease nitrate pollution in drainage channels flowing to coastal lagoons, while having a positive impact on marine habitats and improving shellfish breeding in the Sacca di Goro lagoon;
◦Reduce by at least 30% the amount of water used for irrigation; and
◦Improve the characteristics of soils by the addition of natural zeolites that increase soil ventilation, water retention capacity and cation reserve, allowing good yield even during droughts and/or rainy periods.