Agricultural Reuse of Water and Nutrients from Wastewater Treatment in Turkey Joint Research Project IntenC between TUBS and METU Timur Esemen and PD Dr.-Ing. Thomas Dockhorn Prof. Göksel Demirer
Surface and Ground Water Supply in Turkey Totalusable surface and ground water potentialis110 billion m 3 95 billion m 3 (86%) from rivers located within Turkey 3 billion m 3 (3%) from external rivers 12 billion m 3 (11%) from groundwater resources [1]. Water withdrawal in Turkey [2]: Rural Withdrawal distribution (%) Urban Withdrawal Distribution (%) Spring 24.3 22.1 Lake 0.53 10.3 River 1.54 2.21 Dam 4.90 39.6 Groundwater 67.4 24.1 Pond 0.37 1.57 Other 0.96 0.12 [1] Dilek F., Imamoglu I., Surucu G. and Gokcay C.F., 2007. A Sustainable Waste Water Management Project: MEDAWARE, Conference on Environment: Survival and Sustainability, 19-24 February 2007, Near East University, Nicosia-Northern Cyprus 310-328. [2] The General Directorate of State Hydraulic Works (2002). 2001 Annual Report on Constructed and Opened Irrigation Areas, Department Head of Maintenance and Management, Ministry of Energy and Natural Resources, Ankara, Turkey.
Available Water per Capita Available amount of water per capita is 1735 m 3, the overall potential around 3690 m 3 per capita. Total annual water withdrawal is 42.0 billion m 3 for the whole country by 2000. Annual available water reserves are expected to be around 1100 m 3 per capitaby2030 (Büyükkamaci, 2009).
Water demand in Turkey The sectoral distribution of annual water requirements realized for 2008 and estimated for 2023 are given below: 2008 2023 Irrigation 34 billion m 3 (74 %) 72 billion m 3 (64 %) Drinking Water 7 billion m 3 (15 %) 18 billion m 3 (16 %) Industrial Use 5 billion m 3 (11 %) 22 billion m 3 (20 %) TOTAL 46 billion m 3 112 billion m 3 http://www.dsi.gov.tr/topraksu.htm The water demand for agricultural irrigation is significantly high!
Intended outcomes of the project Existing wastewater infrastructure in Turkey Total potential of water and nutrient recycling from wastewater Presently for irrigation used treated /untreated wastewater resources Comparison of processes required for the reuse of wastewater in regard to efficiency, handling and costs Suitable regions for the implementation of wastewater reuse techniques Regional required measures to ensure an effective reuse of wastewater
Tools Determination of demand and supply Agricultural nutrient and water demand Existing wastewater production Determination of hotspots for case studies Modular design of wastewater/nutrient reuse processes General economic evaluation of reuse modules Determination and economic evaluation of most effective reuse processes for selected regions/hotspots
Determination of hotspots for case studies Demand Supply Demand: Precipitation, evaporation Existing irrigation practices Natural water resources Irrigated areas Supply: Distribution of population Water consumption Wastewater composition WWTP s and used processes
Preparation of a national map provided with required data regarding agricultural demand and supply Demand Supply
Required data is available on the basis of Provinces (81 provinces) and/or Catchment areas (26 catchment areas)
Selected type of division: Catchment areas The map composed of catchment areas will be complemented by obtained data from provincial consideration and will be used for the determination of hotspots 3 different maps will be prepared 1. Water from wastewater 2. Nutrients from wastewater 3. Nutrients from sewage sludge
Waste Water Statistics and Waste Water Treatment in Turkey The total number of settlements with UWWTPs serving for populations in excess of 3 000 capita in Turkey is 138. 70 % of these treatment plants employ secondary or biological treatment while only 7% employ advanced treatment or nutrient removal and 23 % employ physical treatment 10 Advanced, 7% 32 Physical, 23% 96 Biological, 70%
Provinces of Turkey and distribution of the country s UWWTPs In most cases, the effluents of these plants end up with sea discharges.
Population served by UWWTPs in the provinces of Turkey 35% of the total population is being served by UWWTPsin Turkey. This figure is increasing year by year as it was mere 20% in 1994.
TF:trickling filtration; CAS: conventional activated sludge; EAS: extended aeration; NR: nutrient removing; BF: biological filter; SBR: sequencing batch reactor Pond, 24, 23% TF, 10, 9% CAS, 21, 20% Fatta, D., Arslan-Alaton, I., Gokcay, C., Rusan, M. M., Assobhei, O., Mountadar, M., and Papadapoulos, A. (2005), Wastewater Reuse: Problems and Challenges in Cyprus, Turkey, Jordan and Morocco, European Water, 11/12, 63-69. SBR, 1, 1% BF+NR, 1, 1% EAS+NR, 3, 3% CAS+NR, 5, 5% EAS, 41, 38% Conventional activated sludge (CAS) and extended aeration (EA) activated sludge processes are the most commonly used treatment technologies. These two technologies are followed by pond and trickling filtration (TF) systems by 23 and 9 percents, respectively. The number of UWWTPs employing conventional activated sludge process is 21, while those employing extended aeration is 41. NineUWWTPsprovidingnutrientremovalaccountsfor9%ofthetotal.
Indicators of need for wastewater reuse: 2007 has particularly been a dry year where both agricultural and domestic water resources were adversely affected. Some of the precious agricultural land is suffering from groundwater depletion due to over abstraction of water through unregulated wells. The country began to import wheat for the first time due to the decrease in wheat production Sugar beet and seed oil production has gone down.
Wastewater reuse in Turkey Name of Treatment Plant Discharge (m 3 /year) Receiving Body Irrigation Status/Type Kozan Municipality WWTP 278.000 Kozan Stream Indirect / Field Yumurtalik Municipality Packet WWTP 11.000 (Winter) 219.000 (Summer) Ayas Creek Indirect Aksaray Municipality WWTP 9.125.000 Karasu Creek Indirect ASKI Ankara WWTP 192.695.545 Ankara Stream Indirect / Field ESKI WWTP 24.820.000 Porsuk Stream Indirect / Field GASKI WWTP 73.000.000 S. Creek Indirect / Field Igdir Municipality WWTP 2.185.620 Aras River Direct Kayseri WWTP 32.850.000 Karasu Creek Indirect / Field and Feed Plant Ilgin Municipality WWTP 1.095.000 Bulasan Stream Indirect / Field Kadinhani Municipality WWTP 1.356.048 Drainage Canal Direct / Field Urgup Municipality Biological WWTP 32.850.000 Damsa Stream Indirect Bor Municipality WWTP 2.828.750 Emen Plain Direct / Field http://www.uest.gr/medaware/progress.htm
Incident risk distribution related to waterborne diseases for Turkey
Wastewater Reuse Standards Irrigation Water Class Quality Criteria I. Class (very good) II. Class (good) III. Class (usable) IV. Class (usable with caution) V. Class (detrimental, unusable) Chloride (Cl-), meq/l mg/l 0 4 0 142 4 7 142 249 7 12 249 426 12 20 426 710 > 20 > 710 Sulphate (SO4-), meq/l mg/l 0 4 0 192 4 7 192 336 7 12 336 575 12 20 575 960 > 20 > 960 Total salt concentration (mg/l) 0 175 175 525 525 1400 1400-2100 > 2100 Boron concentration (mg/l) 0 0.5 0.5 1.12 1.12 2 > 2 NO3- or NH4+, mg/l 0 5 5 10 10 30 30 50 > 50 Fecal Coliforms** (per 100ml) 0 2 2 20 20 100 100 1000 > 1000 BOD5 (mg/l) 0 25 25 50 50 100 100 200 > 200 Suspended Solid Matter (mg/l) 20 30 45 60 > 100 ph 6.6 8.5 6.5 8.5 6.5 8.5 6.5 9 < 6 or >9 Temperature 30 30 35 40 > 40
Modular design of wastewater reuse processes Modification of existing technologies in regard to wastewater and nutrient recycling Energy kwh (oxygen demand, mixing devices) Energy kwh (electrical energy) Energy kwh Chemicals kg/d Wastewater m 3 /d C kg/d P kg/d N kg/d DS kg/d PST AST V =? m 3 SST V =? m 3 Sewage Sludge m 3 /d DS kg/d C kg/d P kg/d N kg/d Treated Wastewater m 3 /d C kg/d P kg/d N kg/d DS kg/d heavy metals microbio. parameters Wastewater stream m 3 /d C kg/d P kg/d N kg/d DS kg/d Fertilizer kg/d C kg/d P kg/d N kg/d DS kg/d Effluent m 3 /d C kg/d P kg/d N kg/d DS kg/d Energy kwh Thermal energy + electrical energy Energy kwh Electrical Energy Sewage Sludge m 3 /d DS kg/d C kg/d P kg/d N kg/d V =? m 3 Energy kwh gas production thermal energy + electrical energy Wastewater m 3 /d C kg/d P kg/d N kg/d DS kg/d Trickling Filter V =? m 3 Treated Wastewater m 3 /d C kg/d P kg/d N kg/d DS kg/d heavy metals microbio. parameters Digested Sludge m 3 /d DS kg/d C kg/d P kg/d N kg/d Sewage Sludge m 3 /d DS kg/d C kg/d P kg/d N kg/d
Example: Change of construction and operation costs Conventional wastewater treatment P N 2 COD, NH 4 + Comparison V AST -75% Wastewater treatment without nutrient removal COD O 2-50% ES d +5% Fe 3+ -80%
Example: Economic evaluation of activated sludge process The cost calculation will include: Construction costs (related to AST-Volume) Function to describe the correlation between AST-Volume and PE Separation between construction costs and machine costs Energy costs (related to aeration) Energy production by sludge digestion Correlation between sludge age and gas production Sludge disposal costs Personnel costs Next step could be the calculation of benefits for recycled nutrients
Required data for economic evaluation: Wastewater composition (Influent/Effluent) Wastewater treatment costs ( /m 3 ) Sludge disposal costs ( /Mg DS) Sewage sludge composition Fertilizer prices Energy costs Construction costs Operation costs Personnel costs
Case Studies Nutrient and water demand Agricultural activity Mass and energy balances Economic evaluation Regional aspects Available technology (Social aspects) (Issues related to public health) Comparative Decision Tool Decision Tree
Concluding Remarks The required data are highly scattered among different State Authorities. Part of the data necessitated confirmation and are considered to be less reliable. A reliable database must be developed. Sustainable water and wastewater management cannot be promoted unless the existing situation is well defined. The UWWTP effluent reuse potential has to be explored and agricultural reuse has to be practiced. This approach may be used for an introduction of wastewater reuse techniques in Turkey.
Ankara WWTP 800,000 m 3 /d 5,600 kg/d P 32,000 kg /d N