Olfa MAHJOUB 1 and Borhane MAHJOUB 2

Transcription

1 Olfa MAHJOUB 1 and Borhane MAHJOUB 2 1 National Research Institute for Rural Engineering, Water, and Forestry (INRGREF), Tunisia 2 Higher Institute of Agronomy of Chatt Meriem (ISA CM), Tunisia Egyptian-German Workshop on Sustainable Water Technologies SusWaTec Workshop th February Cairo, Egypt 1

2 Introduction Raising the issue on emerging pollutants Wastewater reuse in Tunisia Treatment Fields of reuse Regulation and standards Potential risks related to reuse Research work on emerging pollutants in Tunisia Initiatives Achievements On-going work Constraints Conclusion Perspectives and Challenges 2

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4 Tunisia Area: km2 Population: inhabitants (Tunis: ); 66.3% in urban areas 60% of the territory is arid to semi arid: - North: humid-humid : 1500 mm/y - Center: semi arid: 400 mm/y - South: arid: 100 mm/y 82% of conventional water resources are in the north (78% surface; 14% shallow GW; 8% deep GW. Agriculture (> ha): 83% of the water resources. 4

5 Renewable water resources > 4,800 millions m 3 /y Water share/cap./y m m 3 in

6 National water strategy : - Mobilization of 90% of the available conventional water resources (currently 93% are exploited: surface and ground waters) - Use of non-conventional water (brakich and treated waste water). Treated wastewater: 7% of the total volume allocated to irrigation and 5% of the available water resources. - In 2021: 10% of available water ressources with the potential transfer through piping of millions m3 for reuse in water demanding remote areas. - Long term: 25,000 ha could be irrigated with TWW. 6

7 Advantages of TWW reuse: - Minimize the discharge of polluted water into the receiving environment mitigate environmental and health risks due to chemical and biological pollutants. - Getting benefit of water, nutrients, organic matter, etc. Drawbacks of TWW reuse: Occurrence of : - Macronutrients (N, P, K) - Salts (Na, B, Cl) - Heavy metals and metalloids (Cd, Cr, Zn, etc.) - Emerging pollutants (organic, metabolites and mother compounds). 7

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9 (Grathwohl et al., 2004) 9

10 High rate of production. High rate of consumption. Continuous discharge in the environment detection in surface waters and sediments. The discharge of these substances is rarely or not regulated. (Schrimer, 2009) 10

11 «Any synthetic or naturally occurring chemical (or any micro-organism) that is not commonly monitored in the environment but has the potential to enter the environment and cause unknown or suspected adverse ecological and (or) human health effects» (after USGS, 2000) «New» contaminants: occurrence, risk assessment, and ecotoxicological effects are not available»... «They are suspicious of causing adverse effects in both humans and wildlife» (after Grathwohl et al., 2004) «are relatively new on WFD regulatory lists and evidence regarding their unforeseen adverse health effects and occurrence in the environment are still emerging» (after 1st European workshop on Emerging Contaminants, EMCO, 2005) On the long-term, chronic exposure to low concentrations may geopardize wilde life and human health 11

12 (Brikett et Lester, 2003) 12

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14 Treated WW: 250 Mm 3 /year: 50% produced in Tunis and suburbs. 110 treatment plants: 2 for industrial effluents; 10 with complementary treatment (filtration/uv) Jendouba Kef Kasserine Bizerte Béjà Zaghouan Sousse Kairouan Sidi Bouzid Nabeul Mahdia Sfax Effluents: domestic origin (80%), secondary treated Some organic pollutants are not efficiently removed/degraded transferred to the receiving environment (surface water, groundwater, soils, etc.) after release. Tozeur Gafsa Gabès Kébéli Tataouine Medenine ONAS,

15 Reuse rate: 20-30%. - Potential area to be irrigated with ha - Agricultural irrigation: 8075 ha (Fruit trees, cereals, fodders, industrial crops) - Golf courses: 1040 ha - Landscaping: 450 ha - Artificial aquifer recharge Gharbi

16 Oued Souhil (1980 s) Aquifer recharge pilot plants Korba (2008) 16

17 Water Code (Law enacted in 1975): - Prohibition of reuse of raw wastewater in agriculture and irrigation of vegetables eaten raw. - Reviewed and amended in Set of decrees (1989): conditions of reuse in agriculture. Tunisian Standards for the agricultural reuse of treated wastewater (NT , 1989) 17

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19 Domaine I : Reuse for agricultural purposes. Domaine II : Irrigation of golf courses, landscaping, and gardens in urban areas. Domaine III : Artificial aquifer recharge through infiltration in aquifers which water is used for irrigation. 19

20 Apart from heavy metals, the former and new standards do not take into consideration the occurrence of emerging pollutants in treated waste water Emerging pollutants are not among the priority pollutants to be regulated for now. 20

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22 National Research Institute for Rural Engineering, Water and Forestry (INRGREF) is pioneer in research on wastewater reuse. Regional program (RAB/80/011): : Use of treated wastewater in for crops irrigation and artificial aquifer recharge. Fund: UNDP/Ministry of Agriculture Main objectives - Characterization of TWW (physio-chemical, microbiological ) - Study the impact of reuse on irrigated soils and crops. - Study the impact of sewage sludge use in agriculture. - Feasibility of artificial aquifer recharge. - Contamination of soil and crops by heavy metals - Emerging pollutants have not been studied yet. 22

23 In Tunisia: Research work on the emerging pollutants in water resources started in the early year 2000 s. All work was carried out as joint collaboration projects with foreign Universities (France, Japan). Three leading institutions; all of them associated to foreign research teams: (i) Higher Institute of Biotechnology (Monastir), (ii) Research Center on Water Technologies (CERTE), and (iii) INRGREF. Tunisia: 1st Arab, African country to publish scientific papers on estrogen-like compounds in water. Analyzed samples: aqueous (waste, surface, and ground waters) and solid (soil and sediment) samples. 23

24 Surface water Estrogen -like X Dioxinelike Pesticides Pharmaceuticals Xenobiotics PAHs X Sediments X X PCBs Waste water WW irrigated Soil Ground water X X X X X X X X X X X X X X X X 24

25 2004: 1st paper on estrogenic compounds in WW (Mnif et al.). 2007: 1st paper on estrogenic compounds in water samples (Limam et al.) 2009: 1st paper on estrogenic compounds in irrigation water, groundwater and soils (Mahjoub et al.) 2010: 1st paper on implication of heavy metals in estrogen-like activity in wastewater (Ben Fredj et al.) 2011: 1st paper on estrogen-like and dioxin-like compounds in wastewater and irrigated soils (Mahjoub et al.). 2012: 1st paper on pharmaceuticals residues and their metabolites in wastewater, groundwater, and soil (Fenet et al.). 25

26 EMerging POllutants in Water and WastewatER in Tunisia: EM-PO-W-ER Tunisia (launched in 2012) - TUBS, ISA Chatt Meriem; funded by DAAD (Germany). Reclaimed Wastewater Use for Agricultural Irrigation in North Africa and the Middle East: Mitigating Human and Environmental Risk in Tunisia (launched in 2012) - UF; funded by USDA (USA). Project proposals on pharmaceuticals residues in water and soil (antibiotics, hormones, etc.). Support from partner institutes and countries 26

27 Lack of awareness of the potential negative impacts of pollutants discharge in water bodies. Lack of information on the potential environmental and health risks of some emerging pollutants, except pesticides. Lack of research work on the occurrence, fate and behaviour of emerging pollutants in the environmental in Tunisia. Lack of expertise, advanced equipments and techniques for identification and quantification of these pollutants in environmental matrices and their effects on the ecological system. Lack of federated projects involving Arab countries to deal with this issue. 27

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30 Since secondary wastewater still contain emerging pollutants, agricultural irrigation using treated wastewater is one of the contamination routes of groundwater and soils by these pollutants, with some potential long-term unknown effects. TWW SOIL GROUND WATER - Dissolved compounds: estrogenic and dioxin-like effects, pesticides, pharmaceutical residues, etc. - Low level of estrogenic compounds - Dioxin-like compounds (pesticides, PAH) - Build-up of persistent pharmaceutical residues - Irrigation transfer of soluble water compounds: estrogenic compounds, pesticides, and pharmaceutical residues

31 In Tunisia, research on emerging pollutants has registeded several achievements during the last decade. This research field is still on the learning curve. Data are still scattered and several concerns are still not well addressed: absence of an integrated approach. Research on emergings pollutants in wastewater, effluents irrigated area and groundwater is still not well developed in Tunisia. 31

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33 Upgarding the laboratories and improving the skills of the technical staff and researchers are prerequisites to engage in analysis of residues in environmental samples and obtain reliable data. Establishment of a monitoring priority list of the emerging pollutants in the most sensitive environment. Screening and establishment of monitoring strategies (including identification and quantification) of relevant emerging pollutants in water resources. Establishment an integrated approach for the assessment of chemicals of significant risk for humand health and the environment for a better handling of the potential hazardous effects. 33

34 Lighthouse in Hawaria, Tunisia, 2012 THANK YOU