Olive mill wastewater disposal in evaporation ponds in Sfax (Tunisia): moisture content effect on microbiological and physical chemical parameters

Disposal of untreated olive-mill wastewater (OMW) is a major environmental problem in many Mediterranean countries. This study assessed the impact of OMW application on soil microbiological properties and explored the relationship to soil chemical properties during a 9-month, periodical soil-sampling campaign in a pilot study area in Crete, South Greece. Cases studied involved: direct application of OMW on soil; OMW disposal in active evaporation ponds; sites hosting evaporation ponds that have been inactive for the past 9 years; sites downstream of active evaporation ponds; and control soils, upstream of the waste-disposal ponds. Long-term OMW disposal on land affected the main soil chemical properties. Applicability of the results from the systematic monitoring was confirmed by results obtained in other OMW disposal sites around the pilot area. Soil microbial properties (microbial activity, microbial biomass carbon, and metabolic quotient) were considerably affected by OMW disposal. Moreover, seasonal changes of soil properties revealed short- and long-term residual effects due to OMW disposal. Significant correlations were observed among soil microbial characteristics and soil chemical properties, clearly indicating a close relationship between chemical properties and the transformation of microbial communities in soil after OMW land spreading. The determination of a key set of chemical and microbiological parameters that can be used as indicators for monitoring soil quality at olive-mill waste-disposal areas will verify the efficiency of the techniques used for the land disposal of OMW and will consequently promote their sustainable management.

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Assessment of land suitability for olive mill wastewater disposal site selection by integrating fuzzy logic, AHP, and WLC in a GIS

Environmental Monitoring and Assessment ◽

10.1007/s10661-015-5076-3 ◽

2015 ◽

Vol 188 (1) ◽

Cited By ~ 22

Author(s):

Abdelwaheb Aydi ◽

Tarek Abichou ◽

Imen Hamdi Nasr ◽

Mourad Louati ◽

Moncef Zairi

Keyword(s):

Fuzzy Logic ◽

Site Selection ◽

Olive Mill Wastewater ◽

Land Suitability ◽

Disposal Site ◽

Wastewater Disposal ◽

Olive Mill

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Effects of olive mill wastewater disposal on soil: Interaction mechanisms during different seasons

Journal of Hydrology and Hydromechanics ◽

10.1515/johh-2016-0017 ◽

2016 ◽

Vol 64 (2) ◽

pp. 176-195 ◽

Cited By ~ 10

Author(s):

Nisreen Tamimi ◽

Dörte Diehl ◽

Mohand Njoum ◽

Amer Marei ◽

Gabriele E. Schaumann

Keyword(s):

Preferential Flow ◽

Soil Depth ◽

Water Repellency ◽

Soil Salinization ◽

Olive Mill Wastewater ◽

Negative Effects ◽

Wastewater Disposal ◽

Rain Season ◽

Different Seasons ◽

Olive Mill

Abstract Environmental conditions play a major role for effects of olive mill wastewater (OMW) application to soil. Choosing a different season for OMW application than the commonly practiced winter, may help avoid negative effects. However, understanding of the OMW-soil interaction during different seasons is still incomplete due to the lack of comparative data. In this study, an 18 months field experiment was carried out in an olive orchard in West Bank. Degree and persistence of soil salinization, acidification, accumulation of phenolic compounds and soil water repellency were investigated as a function of soil depth and time elapsed after OMW application, which was performed either in spring, summer (with and without irrigation) or winter. The persistence of negative effects increased with duration of the hot and dry period following the application due to accumulation and polymerization of OMW. On the other hand, leaching of OMW components to groundwater is favored during the rainy season and by formation of preferential flow paths before the rain season starts. The risks of groundwater contamination and persistent negative effects decrease with increasing time under conditions favoring biological activity. Therefore, OMW application in spring if improved by a careful irrigation is considered as the most suitable under semiarid conditions for clay loam soils.

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