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R. Klingbeil, 2011: Boron Concentrations in Desalinated Water: A Real Threat? Review of Health Issues, Technical Aspects and International Guidelines
 

R. Klingbeil, 2011: Boron Concentrations in Desalinated Water: A Real Threat? Review of Health Issues, Technical Aspects and International Guidelines

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Klingbeil, R., 2011. Boron Concentrations in Desalinated Water: A Real Threat? Review of Health Issues, Technical Aspects and International Guidelines. Presentation at the WHO IWA PAEW Regional Water ...

Klingbeil, R., 2011. Boron Concentrations in Desalinated Water: A Real Threat? Review of Health Issues, Technical Aspects and International Guidelines. Presentation at the WHO IWA PAEW Regional Water Safety Plan Conference - Middle East and North Africa Region, 10-12 October 2012, Muscat, Oman.

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    R. Klingbeil, 2011: Boron Concentrations in Desalinated Water: A Real Threat? Review of Health Issues, Technical Aspects and International Guidelines R. Klingbeil, 2011: Boron Concentrations in Desalinated Water: A Real Threat? Review of Health Issues, Technical Aspects and International Guidelines Presentation Transcript

    • Boron Concentrations in Desalinated Water -A Real Threat?Review of Health Issues, Technical Aspectsand International GuidelinesMuscat, Oman10-12 October 2011Ralf KlingbeilRegional Advisor Environment & Water
    • Outline• ESCWA and Regional Advisor services• PAEW request and ToR• Status quo: Boron in drinking water in Oman• Health, toxicology: plants and humans• Boron functions in plants and humans• Removal by reverse osmosis desalination• Drinking water guidelines: global and regional• Conclusions & recommendations1 February 2012 www.escwa.un.org 2
    • 1 February 2012 www.escwa.un.org 3UN ESCWA• 14 Member Countries• Bahrain• Egypt• Iraq• Jordan• Kuwait• Lebanon• Qatar• Oman• Palestine• Saudi Arabia• Sudan• Syrian Arab Republic• United Arab Emirates• Yemen
    • 1 February 2012 www.escwa.un.org 4OrganizationalChart
    • Sustainable Development and ProductivityDivision and RA Environment & Water1 February 2012 www.escwa.un.org 5WaterEnergyProductiveSectors§ Energy efficiency§ Access to modernenergy services§ Renewableenergies§ Advanced/cleanerfossil fuels§ Rural electrification§ Sustainable energyuse in transport§ Integrated waterresourcemanagement(IWRM)§ Management ofshared waterresources§ Improved watersupply andsanitation§ Competitivenessand productivity ofSMEs§ Environmentallysound technologies§ Sustainableagriculture andrural development§ Trade andenvironmentCross-cutting issues:§ Climate change adaptation and mitigation§ Sustainable consumption and production§ Green economy
    • RA Environment & Water 2009-10• Modalities– Policy Advice, TechnicalSupport and Advocacy– Training & CapacityBuildingWorkshops, Study Tours,Fellowships– Regional KnowledgeNetworkingPartnerships w Centers ofExcellence– Field ProjectsPilot projects with seed money• Total requests 2009-2010:– Environment: 38– Water: 601 February 2012 www.escwa.un.org 6Status:End of 2010
    • RA / TC Example Projects• Ministry of Economy and Planning (MoEP), Saudi Arabia– Contribution to “Assessment and Strategic Management of theWater Sector”, Jul 2009 – Jan 2010• Ministry of Municipalities Affairs and Urban Planning(MMAUP), Bahrain– Contribution to national approach to “Managed Aquifer Rechargeand Reuse of Treated Sewage Effluent”, since Sep 2010• Public Authority of Electricity and Water (PAEW), Oman– Various contributions to “Drinking Water Quality Aspects inOman”, since May 2009• Ministry of Water and Irrigation (MWI), Jordan– Assistance in “Groundwater Monitoring of Disi TransboundaryAquifer”, in cooperation with BGR, Germany, since Apr 20091 February 2012 www.escwa.un.org 7
    • • Assistance in ReviewingAppropriate GuidelineValues for Boron inDrinking Water for theSultanate of Oman– Desk Study:Nov-Dec 2011– Meeting at PAEW:22 Dec 2010– Report presentation:19 Mar 20111 February 2012 www.escwa.un.org 8
    • PAEW Request and ToR1. Study the impact of boron on consumer health,2. Review permissible concentrations of boron indrinking water at the global level and in theESCWA region, and3. Review and discuss appropriate guidelinevalues for boron in drinking water for Oman.1 February 2012 www.escwa.un.org 9
    • Boron in Drinking WaterGuideline values:• Earlier global and current Omani guideline value,WHO (2008) & MoCI (2006):– 0.5 mg/l• New global guideline value,WHO (2011):– 2,4 mg/l• Single stage SWRO membranes can reduce borononly to about 0.9-1.8 mg/l• Even two stage RO process often insufficient toachieve 0.5 mg/l guideline• Expensive to remove boron to achieve strictguideline values1 February 2012 www.escwa.un.org 10
    • Boron in Drinking Water in Oman:Desalination Product Water1 February 2012 www.escwa.un.org 11
    • 1 February 2012 www.escwa.un.org 12Boron in Drinking Water in Oman:Desalination Product and Feed WaterRegion Wilayat PlantBoron concentration (mg/l)2007 2008 2009 2010Product FeedAl WustaMahoutHij 1.049 1.632 0.920 1.380Mahout 1.125 0.973 0.870 0.930Khaloof 1.754 1.754 1.430Al Sail AlRamla1.529 1.037 1.170 1.020Al Nagda 0.330Al JazerEshairija 0.48 0.601 0.601 1.42Al Lakbi 1.805 1.957 1.420 1.82 7.25Kahal 0.187 0.299 0.150 0.65 3.63Al DaqumAl Sadanat 0.552 0.758 0.610 1.22 5.43Ras AlMadrkah2.73 1.280 2.09 7.22Dhahar 0.74 0.843 0.730 0.89 3.54Hitam 0.42 0.72 0.680 1.21 5.09Haima Haima 0.600 1.67 6.03Al SharqiaSurSur 1.154 1.18 0.420Tiwi 1.820 1.820Ras Al Had 1.04 1.032 1.27 1.960Jalan banibu AliAsselah 1.12Ruwais 0.53Khuwaima 1.275 1.188 1.02 1.28Al Dakhila AdamAl zahya 0.725 1.116 1.116 1.300Adam 0.555 0.704 0.570 0.670Qarn AlAlam1.006 1.342 1.220 1.840
    • 1 February 2012 www.escwa.un.org 13Boron in Drinking Water in Oman:Desalination Product and Feed WaterRegion Wilayat PlantBoron concentration (mg/l)2007 2008 2009 2010Product FeedMuscatMuscatAl Ghubrah 0.02 0.01 0.02 0.100Sifah 1.237 1.306 1.070 1.57 5.02Khairan 0.273 0.521 0.440 0.62 3.91QuriyatFins 1.169 1.145 0.940 1.19 4.42Bamah 1.64 0.845 0.720 1.34 5.24Daghmar 1.550 1.26 4.88SouthBatinahBarkahBarkah 1 0.0 0.0 - 0.060Barkah 2 0.0 0.0 0.770 0.50MusandamKhasabSheesa 1.228 2.220 2.43Lima ROPlant0.803 0.760 1.02Lima EDPlant0.700 1.05Daba Diba 0.679 1.550 2.07Al Dhahirah IbriHamra Aldrua0.880 0.890NorthBatinahSohar Sohar 0.011 0.019 - 0.03
    • Boron in Drinking Water in OmanStatus in Oman, as of March 2011:• Desalination product water 2007-2010:– Only 16% comply with strict 0.5 mg/l guidance– 84 % are above 0.5 mg/l guideline– Only 1.8% are above the 2.4 mg/l level• Product water from RO desalination plantswithout any further 2nd pass are often not incompliance with today’s standards1 February 2012 www.escwa.un.org 14
    • Natural Occurrence: Boron in Water• Boron concentration in seawater: 4.5 - 7 mg/l:– un-dissociated boric acid B(OH)3, pH < 9.2– ionized borate B(OH)4-, pH > 9.2• Found naturally in groundwater– primarily leaching from rocks and soilscontaining borate and borosilicate• Released through– weathering processes and– anthropogenic discharges such as sewage outfalls• Adsorption-desorption reactions only significantmechanism influencing boron in water• Extent of boron adsorption depends on– pH of water and– concentration of boron in solution1 February 2012 www.escwa.un.org 15
    • Health, Toxicology: Plants• Symptoms: “burned edges” on older leaves,yellowing of leaf tips, accelerated decay• Relative tolerance of agricultural crops to boron1 February 2012 www.escwa.un.org 16
    • Health, Toxicology: Humans• Symptoms: respiratory irritation, incl.nosebleeds, eye and nasal irritation, sorethroats, cough, shortness of breath, dermatitis• Absorption rate of 83-94%, nearly completelythrough inhalation and dermal contact• Lethal doses boric acid:– oral exposure: 640 mg/kg body weight– dermal exposure: 8600 mg/kg body weight– intravenous injection: 29 mg/kg body weight– 5-20 g for adults– < 5 g for infants• No data on carcinogenicity1 February 2012 www.escwa.un.org 17
    • Health, Toxicology: HumansAccidental intake and poisoning• Symptoms: gastrointestinal tract disturbances,vomiting, abdominal pain, diarrhea, nausea,lethargy, rash, headache, light-headedness,fever, irritability and muscle cramps• Intakes in the range of– 30.4 – 94.7 mg B/kg body weight / day, infants– twice 45 g intake in 12h interval• Lethal doses presumably:– 15-20 g for adults– 5-6 g for children– 2-3 g for infants1 February 2012 www.escwa.un.org 18
    • Health, Toxicology: HumansBoron in drinking water and diets• Positive correlation betwen boron in drinkingwater and blood:– < 2.5 mg/l boron in drinking water  < 0,1 µg/g blood– 15.2 mg/l boron in drinking water  0,7 µg/g blood• No conclusive evidence for impact on fertility orother reproductive outcomes• High boron diet (3 mg/day) enhances someparameters in relation to oestrogen therapy inpost-menopausal women1 February 2012 www.escwa.un.org 19
    • Boron Functions in Plants and HumansPlants:• Essential micronutrient affecting plant growth and development• In irrigation water / soils important for crop yields and quality ofproduce• Deficiency may exhibit a wide range of symptoms: necrosis,abnormalities related to the breakdown of internal tissuesHumans:• Biochemical function of boron remains undefined• Potential nutritional importance as dynamic trace element affectingmetabolism or utilization of numerous substances in life processes• Deprivation results in changed biological functions that aredetrimental• Supplementation may improve osteoarthritis and rheumatoid arthritis• May reduce risk of inflammatory disease by down-regulatingenzymes of inflammatory response1 February 2012 www.escwa.un.org 20
    • Boron Removal ProcessesBasically three technologies:• Boron-specific ion exchange resin,• Strong base anion-exchange resin, and• Reverse Osmosis (RO):– Sea Water Reverse Osmosis (SWRO)• semi-permeable membrane• most of the dissolved species are rejected• water permeates it1 February 2012 www.escwa.un.org 21
    • Boron Removal Processes:Different RO Processes• Boron removal process for seawaterdesalination, feed conc. 4-5 mg/l, 18-26 °C1 February 2012 www.escwa.un.org 22
    • Boron Removal Processes:Chemistry in Seawater• Concentration in seawater: 4.8 – 7 mg/l• Two forms of boron:– boric acid B(OH)3– borate B(OH)4-• Dissociation constant pKa (boric acid / borate):f (temperature, pressure, pH, ionic strength)•• Removal of non-ionized boric acid by ReverseOsmosis (RO) is low due to its smaller size andlack of electric charge1 February 2012 www.escwa.un.org 23
    • Boron Removal Processes:Effect of Different ParametersParameter Boron rejectionpH increases IncreasesFeed pressure increases IncreasesFeed temperature increases DecreasesFeed salinity (ionic strength)increasesDecreasesRecovery ratio increases DecreasesMannitol or Fe increases IncreasesFeed flow rate increases No effectInitial boron concentrationincreasesNo effect1 February 2012 www.escwa.un.org 24
    • Boron Removal Processes:Chemistry in Seawater• Distribution of boric acid and borate in seawater1 February 2012 www.escwa.un.org 25
    • Boron Removal Processes:Effect of Temperature Change• Increased temperature results in an reduction inboron removal– Total flux through RO membranes incl. salt fluxincreases at higher temperature– Reduction to 70% at 25 °C / 72% at 35 °C1 February 2012 www.escwa.un.org 26
    • Boron Drinking Water Standards:Global & Regional• How to develop a guideline value for boron?– NOAEL = No Observed Adverse Effects Level:The adverse effect judged to be most appropriate is thereproductive toxicity based on Heindel et al., 1992 andPrice et al., 1994.– Uncertainty Factor:Based on interspecies and intraspecies factors– TDI = Tolerable Daily Intake:Estimate of the intake of a substance that can occur over alifetime without appreciable health risks– Allocation to water:Percentage of TDI allocated to water intake1 February 2012 www.escwa.un.org 27
    • Boron Drinking Water Standards:Global & RegionalWHO EU AUS CAN USAYear 2008 2011 1998 Future20042008 2009AROINOAEL (mg/kg/d) 9.6 10.3 - 10.3 9.6 - - 10.3Uncertainty factor 60 60 - 60 60 - - 66TDI (mg/kg) 0.16 0.17 - 0.17 0.16 - - 0.2Allocation to water(%)10 40 - 40 10 - - 80Body weight (kg) 60 60 - 60 70 - - 70Waterconsumption (l/d)2 2 - 2 2 - - 2GUIDELINE (mg/l) 0.5 2.4 1 2.4 0.6 4 5 61 February 2012 www.escwa.un.org 28
    • Boron Drinking Water Standards:Global & RegionalBAH EGY IRQ JOR KUW LEB OMNYear 1999 2007 2001 2005 1999 1996 2006Guideline (mg/l) -- 0.5 1.0 2.0 0.5 -- 0.51 February 2012 www.escwa.un.org 29oPt SAU SUD SYR UAE YEMYear 1997 2000 2002 1994 -- --Guideline (mg/l) -- 0.5 0.2 0.3 -- --• Global and regional standards vary from 0.2 to 6 mg/l• Global guidelines derived from formula• 4 of 13 countries in the region follow 2008 WHO guideline• No information available on derivation of regional guidelinesnor about their compliance monitoring
    • Conclusions & Recommendations 1/2• Oman may wish to review present drinking waterstandards with respect to the element of boron• Change of drinking water guidelines for boronjustifiable– from 0.5 mg/l to proposed new guidance 2.4 mg/l• Precautions to be taken for boron > 0.5 mg/l forplant irrigation– cost effectiveness of additional boron removal forlocal irrigation vs. resettlement of irrigated plantation1 February 2012 www.escwa.un.org 30
    • Conclusions & Recommendations 2/2• Major source of boron is seawater (4.5 - 7 mg/l):– un-dissociated boric acid B(OH)3, pH < 9.2– ionized borate B(OH)4-, pH > 9.2– Small and uncharged boric acid minerals can diffuse through theRO membrane– Increasing pH, feed pressure or complexation reactions increaseboron removal rates,– Increasing temperatures in feed water reduce boron removalrates• Current global and regional standards for boron indrinking water vary from 0.2 mg/l to 6 mg/l• Insufficient information to prove harmful effects onhuman beings• Expensive boron removal to achieve strict 0.5 mg/lguideline value1 February 2012 www.escwa.un.org 31
    • Further Suggestions• Options for “mobile 2nd pass RO membranes”?– Feasibility of developing or using mobile / container-based 2nd pass membranes for boron > 2.4 mg/l• Accompanying research?– An increase in guideline values for boron in Omancould be accompanied with research related toenvironmental health with communities largelydepending on boron > 0.5 mg/l– Joint regional or bilateral research cooperation withSaudi Arabia, GCC and/or ESCWA countries:• GCC countries depend largely on desalination for drinkingwater• Boron challenges are largely restricted to RO desalinationmainly used in Oman and Saudi Arabia1 February 2012 www.escwa.un.org 32
    • Latest Status:New 2011 WHO Guidance• WHO, July 2011.Guidelines for Drinking-Water Quality, 4th ed.– BoronGuideline value 2.4 mg/l (2400 μg/l)– http://www.who.int/water_sanitation_health/publications/2011/dwq_guidelines/en/#• WHO, March 2011.Safe drinking-water from desalination– Boron and borate(…)– http://www.who.int/water_sanitation_health/publications/2011/desalination_guidance/en/index.html1 February 2012 www.escwa.un.org 33
    • Most Relevant References• Al-Busaidi, A. (2004). Desalination in Oman and the fundamentals of reverse osmosis design.Sultanate of Oman, Ministry of Housing, Electricity and Water.• Hilal, N., Kim, G.J., Somerfield, C. (2010). Boron removal from saline water: A comprehensivereview. Desalination, 223, pp. 10-23.• Kabay, N., Guler, E., Bryjak, M. (2010). Boron in seawater and methods for its separation - Areview. Desalination, 261, pp. 212-217.• Ministry of Commerce and Industry (2006). Omani Standards for unbottled drinking water.Directorate for Specifications and Measurement (OS 8/2006), p. 6.http://www.pdo.co.om/hseforcontractors/blocks/documentation/docs/laws/Omani%20St%20Eng-full.pdf• UK Expert group on vitamins and minerals (2002). Revised review of boron.http://www.food.gov.uk/multimedia/pdfs/boron.pdf• U.S. EPA (2004). Toxicological review of boron and compounds (CAS 7440-42-8). U.S.Environmental Protection Agency, Washington, DC. EPA 635/04/052.http://www.epa.gov/ncea/iris/toxreviews/0410tr.pdf• WHO (2008). Guidelines for drinking water quality, 3rd Ed., World Health Organization.http://www.who.int/water_sanitation_health/dwq/fulltext.pdf• WHO (2009). Boron in drinking-water: Background document for development of WHO Guidelinesfor drinking-water quality. World Health Organization.http://whqlibdoc.who.int/hq/2009/WHO_HSE_WSH_09.01_2_eng.pdf• WHO (2011). Safe drinking-water from desalination. World Health Organization.http://www.who.int/water_sanitation_health/publications/2011/desalination_guidance/en/index.html• WHO (2011). Guidelines for Drinking-water Quality. 4th Ed. World Health Organization.http://www.who.int/water_sanitation_health/publications/2011/dwq_guidelines/en/#1 February 2012 www.escwa.un.org 34
    • Boron Concentrations in Desalinated Water -A Real Threat?Review of Health Issues, Technical Aspectsand International GuidelinesMuscat, Oman10-12 October 2011Ralf KlingbeilRegional Advisor Environment & Water