Wastewater Treatment Plants : Wastewater Resource Recovery Facilities

Wastewater treatment plants : wastewater resource recovery facilities ? C. Wisniewski Montpellier University, France UMR QualiSud Faculté des Sciences Pharmaceutiques et Biologiques Wastewater treatment plants : wastewater resource recovery facilities ?

Wastewater Treatment adaptation according to Climate Change OUTLINES Current state of Wastewater Treatment (WWT) Climate Change's Relation to Wastewater Treatment A new Paradigm for Wastewater Treatment Plant (WWTP) Wastewater treatment plants : wastewater resource recovery facilities ?

Municipal sewage effluent WASTEWATER Industrial effluent Urban and agricultural runoff WASTEWATER TREATMENT PLANTS Parameter mg/L TSS 250 to 600 COD 500 to 1200 BOD 230 to 560 N total 30 to 100 P total 6 to 25 Level of treatment required before discharge imposed by European Directives DISCHARGED IN WATER BODIES Wastewater treatment plants : wastewater resource recovery facilities ?

Urban Wastewater Treatment Directive (91/271/EEC1) SIGNIFICANT IMPACT ON WASTEWATER TREATMENT Objective Protection of the aquatic environment from the adverse effects (such as eutrophication) of urban (and industrial) wastewater Collection and treatment of wastewater in all agglomerations with a population equivalent larger than 2000 Parameter mg/L % reduction COD 125 75 BOD 25 70 - 90 N total Phosphorus and Nitrogen Sensitive areas 10 - 15 80 P total 1-2 Implementation and Improvement of many WWTPs the last few years Wastewater treatment plants : wastewater resource recovery facilities ?

Water Framework Directive (2000/60/EC2000) Objective Protection and restoration of clean water across Europe Achieve “good status” by 2015 and to prevent deterioration to water bodies Identification of priority substances that have to be reduced in water bodies Micro-pollutant Emerging contaminants Implementation of additional treatment steps in many WWTPs Wastewater treatment plants : wastewater resource recovery facilities ?

CONVENTIONNAL WASTEWATER PLANT TODAY Pre-treatment Primary treatment Removal of suspended solids (settling) Secondary treatment Tertiary treatment Removal of organic matter and of some nutrients (aerobic or anaerobic processes) Improvement of the effluent quality before its discharge (effluent polishing) DISCHARGE Wastewater treatment plants : wastewater resource recovery facilities ?

CONVENTIONNAL WASTEWATER PLANT TODAY Pre-treatment Primary treatment Secondary treatment Sludge treatment Tertiary treatment DISCHARGE Wastewater treatment plants : wastewater resource recovery facilities ?

CONVENTIONNAL WASTEWATER PLANT TODAY A SIMPLE WASTE TREATMENT UNIT REQUIRING ENERGY PRODUCING SLUDGE ENERGY SLUDGE What is the future of WASTEWATER TREATMENT plants? CLIMATE CHANGE Wastewater treatment plants : wastewater resource recovery facilities ?

WWT Impact on Climate Change Climate Change Impact on WWT What is the future of WASTEWATER TREATMENT plants? CLIMATE CHANGE Wastewater treatment plants : wastewater resource recovery facilities ?

Climate Change Impact on WWT Earlier snowmelt Increased evaporation rates Temperature elevation Higher climate variability Changes in frequency and timing of precipitation events Extreme weather events More intensive rainfall events Very few references on the assessment of climate change impacts on WWT Wastewater treatment plants : wastewater resource recovery facilities ?

Modification of BIOLOGICAL REMOVAL RATES Modifications of SOLIDS-LIQUID SEPARATION Temperature elevation Conventional Process models unable of describing and predicting the effects of SHOCK-LOADING EVENTS Increase of sewage influent PEAK FLOW RATES Changes in frequency and timing of precipitation events Combined sewers Large majority of existing sewers in most EU countries Water Sci Technol. 2009, 60(2):533-540 Wastewater treatment plants : wastewater resource recovery facilities ?

WWT Impact on Climate Change SIGNIFICANT IMPACTS on the overall environmental performance ENERGY SLUDGE GREENHOUSE GAS (GHG) EMISSIONS Wastewater treatment plants : wastewater resource recovery facilities ?

Global Greenhouse Gas Emissions by Source (USA) GHG emissions from wastewater represent 0,6 % Intergovernmental Panel on Climate Change (IPCC), 2007 . Wastewater treatment plants : wastewater resource recovery facilities ?

GHG emissions Nitrous oxide (N2O) Carbon dioxide (CO2) Methane (CH4) CO2 CH4 N2O N2O CH4 Sludge thickening and disposal Wastewater treatment plants : wastewater resource recovery facilities ?

Carbon dioxide from aerobic process Methane from anaerobic processes CH4 Nitrous oxide from nitrification/denitrification processes CO2 CH4 N2O N20 Sludge thickening and disposal Managing Water Resources under Climate Uncertainty, Part of the series Springer Water. 2001 : 197-220 Wastewater treatment plants : wastewater resource recovery facilities ?

REMOVE ORGANIC MATTER NITROGEN PHOSPHOROUS Micropollutant GENERATE SOLID WASTE GHG CONSUME ENERGY Wastewater treatment plants : wastewater resource recovery facilities ?

A NEW PARADIGM FOR WWTP IS NOW NECESSARY ENERGY SLUDGE GHG Treatment and disposal FACTORY Resources recovering and recycling Extracting resources from wastewater is not new but becomes crucial WHAT CAN WE GET FROM WASTEWATER? Wastewater treatment plants : wastewater resource recovery facilities ?

WHAT CAN WE GET FROM WASTEWATER? Energy Nutrient Other value-added materials Water (for reuse) resource-recovery/ Wastewater treatment plants : wastewater resource recovery facilities ?

Energy There is more energy in wastewater than is required to treat it There are different types of energy in wastewater Biological/chemical Energy In the ORGANIC MATTER 1 m3/d 0.05 kW Heat Energy assuming that a 12 change in temperature could be extracted 0.26 kW Energy demands 0.02 kW 15 times higher than the energy required for treatment resource-recovery/ Wastewater treatment plants : wastewater resource recovery facilities ?

Power Positive Wastewater Treatment power production equivalent to the power demand 0.02 kW Biological/chemical Energy In the ORGANIC MATTER 40% of this energy can be converted into electrical power 0.05 kW Low-grade heat Low energy quality Heat Energy assuming that a 12 change in temperature could be extracted 0.26 kW Any significant amount of power produced resource-recovery/ Wastewater treatment plants : wastewater resource recovery facilities ?

Energy LARGE DEVELOPMENT OF ANAEROBIC PROCESSES FOR ORGANIC MATTER REMOVAL Aerobic treatment requires air and demands more power than anaerobic treatment that produces biogas that can be used to fuel power production. Research about conversion of digester gas (methane) into methanol Anaerobic digestion might be coupled with other process to produce methanol, ammonia, or other products from digester gas. 5257/104844 resource-recovery/ Wastewater treatment plants : wastewater resource recovery facilities ?

Nutrient Recovery PHOSPHOROUS NITROGEN Wastewater contains nutrients such as phosphorus and nitrogen MOTIVATIONS Non-renewable resource for which there is no substitute Rise in P prices due to increasing fertilizer demand Abundant in the atmosphere BUT takes a considerable energy input to capture it and convert it into a fertilizer product Volatility of the natural gas market Wastewater treatment plants : wastewater resource recovery facilities ?

PHOSPHOROUS Approximately 18% of the EU’s total phosphorus goes into sludge and could be recycled Many countries are starting to promote measures to recover phosphorus from wastewater Switzerland Sweden UK and Germany nutrient-recovery-energy-and-resource-recovery/ Wastewater treatment plants : wastewater resource recovery facilities ?

PHOSPHOROUS Ion exchange and adsorption Bio-electrochemical system Membrane separation NITROGEN Chemical precipitation Biological assimilation Chemical reduction and extraction Physical-chemical adsorption and ion exchange Physical filtration and membrane process Water Pollution . 2015, 1 (3) : 155-166 Wastewater treatment plants : wastewater resource recovery facilities ?

NITROGEN and PHOSPHOROUS Nitrogen and Phosphorus recovered by precipitation (e.g. struvite) Both Phosphorus and Ammonium can be simultaneously removed and precipitates can be used as a fertilizer. Separation of urine and solids Urine accounts for only 1% of the total volume of wastewater, but it contains up to 80% of all the nutrients. Urine contains phosphate (PO4) and ammonium (NH4). When magnesium (Mg) is added to urine, phosphate, ammonium and magnesium bind and form struvite (MgNH4PO4 6H2O), which can then be filtered out, collected, and dried into a powder http://www.sswm.info/content/struvite-0 Wastewater treatment plants : wastewater resource recovery facilities ?

NITROGEN and PHOSPHOROUS Large-scale Application of Phosphorus (Struvite) Recovery from Digested Municipal Sludge "Stuttgart Process" The process is distinguished by the fact that municipal sewage sludge from wastewater treatment plants with simultaneous phosphate elimination with iron salts could be used without any changes in the process of wastewater treatment. The resulting product can be applied, for example, directly as fertilizer in agriculture. t/2012 2013 Forschungsprojekte/Pilotanlage MAP.en.html Wastewater treatment plants : wastewater resource recovery facilities ?

Other value-added materials Identification of 13 lucrative elements Platinum, silver, iron, zinc, copper, gold U.S. sewage sludges were analyzed for 58 elements by ICP-MS and electron microscopy 2 million 1 ton of sludge 16,7 g Ag - 0,33 g Au Environ. Sci. Technol. 2015, 49 (16): 9479–9488 Wastewater treatment plants : wastewater resource recovery facilities ?

LIST OF MATERIALS THAT CAN BE POTENTIALLY EXTRACTED FROM WASTEWATER PHA (polyhydroxyalcanoate) Production Biopolymers of commercial interest PHA storage is a widespread bacterial property Nutrient Recovery: State of the Knowledge 2011, Water Environment Research Foundation Wastewater treatment plants : wastewater resource recovery facilities ?

Water Reuse CLIMATE CHANGE Wastewater reuse will become more necessary as climate change accelerates Decrease in the availability of freshwater Deterioration of freshwater resources DEMAND FOR ALTERNATIVE POTABLE SUPPLY SOURCES Wastewater treatment plants : wastewater resource recovery facilities ?

Pre-treatment Primary treatment Secondary treatment Tertiary treatment Sludge thickening and disposal Wastewater treatment plants : wastewater resource recovery facilities ? R E U S E

Membrane bioreactor (MBR) Pre-treatment Primary treatment High wastewater discharge quality High level of wastewater recycling Sludge thickening and disposal Wastewater treatment plants : wastewater resource recovery facilities ? R E U S E

Membrane bioreactor (MBR) Pre-treatment Primary treatment Increase of the global market for membrane bioreactors Sludge thickening and disposal Wastewater treatment plants : wastewater resource recovery facilities ? R E U S E

A new paradigm for WWTPs Treatment and disposal FACTORY Resources recovering and recycling MESURES Effective and cost efficient Without side-effects Promoting equity Technically and socially feasible Preventing long term negative effects Wastewater treatment plants : wastewater resource recovery facilities ?

A new paradigm for WWTPs Energy factory Changes in polices and regulations How much will it cost and who will finance it? Nutrient factory Water factory Changes in public attitude (e.g. to use reclaimed water) What limits will be imposed? wastewater reuses, and energy and nutrient recovery from wastewater have to be actively encouraged Wastewater treatment plants : wastewater resource recovery facilities ?

Wastewater treatment plants : wastewater resource recovery facilities ? NITROGEN and PHOSPHOROUS The process is distinguished by the fact that municipal sewage sludge from wastewater treatment plants with simultaneous phosphate elimination with iron salts could be used without any changes in the process of wastewater treatment.