New and Innovative Rare Earth Technology for Low-Level Phosphorus Removal Presented to: By: Date:

Size: px

Start display at page:

Download "New and Innovative Rare Earth Technology for Low-Level Phosphorus Removal Presented to: By: Date:"

Clement Kelly
7 years ago
Views:

1 New and Innovative Rare Earth Technology for Low-Level Phosphorus Removal Presented to: By: Date: Conference on the Environment Pam Cornish Business Development Manager Nov 19,

2 Discussion Outline Rare Earth Technology Introduction What are rare earths? Rare earths vs. traditional P removal Preliminary Lab Studies Plant Trials Equipment Set-up Facility processes Trial results Conclusions 2

3 Rare Earth Technology Rare earth elements are located in the lanthanide series (plus Sc and Y) of the periodic table Most prominently known for high strength, permanent magnets Unique reactivity with oxyanions, such as phosphate 3

4 Uses for Lanthanum & Cerium Traditional Markets Emerging Markets Glass Polishing Hybrid Vehicle Batteries Recreation Water Catalytic Converters Advanced Optics Wastewater 4

5 5 Rare Earth Mine in United States

6 Phosphorus Removal Mechanism Rare earth elements form strong, crystalline bonds with phosphorus Forms insoluble rhabdophane precipitate Iron and aluminum based products form amorphous cloud in solution Adsorbs phosphate onto metal hydroxide floc 6

7 Why RE is different than traditional coagulants Precipitate is CePO 4 / LaPO 4 (Rhabdophane) Forms ionic bonds Preferentially reacts with phosphorus Achieves nearly a 1:1 molar ratio of Ce:PO 4 Reduced chemical sludge Forms Fe/AlOOH and Fe/Al(OH) 3 intermediates to adsorb P Phosphate adsorbs on the surface of the floc (surface chemistry) 7

8 Product Characteristics Rare earth chloride solution Active Ingredient: Cerium Chloride (CeCl 3 ) Concentration: 31.5% Density: 12.4 lbs/gal Freezing Point -40 F ph: 3.5 Non-hazardous rating Compatible with existing equipment 275 gallon totes / 3600 gallon tankers 8

9 9 Coagulant Comparison 2.5 mg/l

10 10 Coagulant Comparison 1 mg/l

11 11 Coagulant Comparison Varying Initial P

12 12 Field Trials Equipment Set-up

13 Case Study #1 45 MGD municipal WRF located in Mid-Atlantic United States Total phosphorus limit of 0.18 mg/l P Target of 0.10 mg/l P Interested in seeking new coagulant with lower consumption rate, less chemical solids produced, and less staining of UV Coagulant Addition Point Sample Point Raw Influent following Screening Primary Clarification Enhanced Biological Nutrient Removal Secondary Clarification Tertiary Clarification Filtration/ Disinfection Final Effluent Return Activated Sludge Sample Point 13

14 Case Study #1 CeCl 3 maintained phosphorus below limit with dosage rate 3x less than FeCl 3 Ferric 34 ppm v 3.5:1 Fe/P SorbX Dose 11 ppm v 0.7:1 Ce/P 14

15 Case Study #2 11 MGD municipal WRF located in Northeast United States New total phosphorus limit of 0.10 mg/l P Down from limit of 0.70 mg/l P Ferric chloride use has caused: Corrosion damage Staining of equipment and facility Discoloration of water Facility wanted to discontinue use of ferric chloride due to above issues Sample Point Coagulant Addition Point Sample Point Sample Point Sample Point Raw Influent following Screening Primary Clarification Enhanced Biological Nutrient Removal Secondary Clarification Disinfection Final Effluent Return Activated Sludge 15

16 Case Study #2 Solids being recycled through RAS stream continued to lower P upstream of addition point due to extended solids contact time 16

17 City of Hartford, WI 2 MGD municipal WWTF located in Wisconsin Total P limit of 1.0 mg/l New limit of mg/l being enacted Uses ferrous chloride (FeCl 2 ) for chemical P removal No dedicated biological P removal system Unable to meet new TP limits with current coagulant Sample Point Sample Point Coagulant Addition Point Sample Point Sample Point Raw Influent following Screening Primary Clarification Oxidation Ditch Secondary Clarification Filtration/ Disinfection Final Effluent Return Activated Sludge Waste Sludge Waste Sludge 17

18 Hartford achieved mg/l effluent Total P (mg/l P) Inf TP AB Eff TP FE TP CeCl3 Dosage CeCl 3 Dosage Rate (ppm v ) Date CeCl 3 maintaining avg effluent TP < mg/l with dose rate of 50 ppm v (equivalent to molar ratio 1.4:1 Ce/P) Historical ferrous usage required ppm v and only reduced TP to avg of 0.5 mg/l 18

19 City of Hartford, WI Dosage Curve Average TP in Final Effluent (mg/l) TP Removal Curve Hartford, WI CeCl3 Dosage CeCl 3 Dose Rate (GPD) 19

20 City of Hartford, WI Dosage Curve Average TP in Final Effluent (mg/l) TP Removal Curve - Hartford, WI SorbX-100 Dosage Molar Ratio Ce/P 20

21 Sludge Volume Reduction Sludge cake being formed on the table Sludge cake in the conveyor Sludge ready for land application Hartford: We were wasting 100,000 gallons per day of sludge, now we are down to less than gallons per day. Campbell s: We ve seen a 60% reduction in sludge volume, much better than alum. 21 Albion: We have doubled our belt filter press throughput, compared to iron and aluminum.

22 Fast Coagulation Performance Before SorbX Addition 12 hours after SorbX Addition Plant Operator: In 30 years of working here, I have never seen the clarifier look that clear! 22

23 Fast Coagulation Performance Plant Effluent from 3.6 mg/l-po4 to 0.6 mg/l-po4 in 48 hours 23

24 Fast Coagulation Performance Mixed Liquor sample - settling Initial 1 min 2 min 4 min 5 min 10 min 24

25 Conclusions Observed Benefits of Rare Earth Technology Able to achieve very low TP discharge limits without capital equipment Reduced sludge volumes compared to competitive coagulants Faster coagulation and noticeable impact than competitive coagulants Less coagulant volume required to reach low phosphorus limits Improved water clarity due to good coagulation properties Will not stain or discolor facility structures or equipment Compatible with existing dosing and filtration equipment Rated non-hazardous for DOT regulations 25

26 Questions? Pam Cornish

27 Temperature CeCl 3 dose remains consistent through wide range of temperature Temperature ( F) Molar Ratio Ce:P CeCl 3 Dosage (ppm v ) Dosages required to reduce P from 0.5 mg/l down to 0.1 mg/l 27

28 Effluent Toxicity Testing Sample tested: Secondary clarifier effluent Phosphorus Level: Spiked to 2 mg/l PO 4 -P using NaH 2 PO 4 Treated with CeCl 3 at volumetric dose rate of 50 ppm v Filtered and unfiltered samples submitted for acute whole effluent toxicity testing 28

29 California WET Extraction Samples Tested: Secondary clarifier effluent (spiked to 2 mg/l PO 4 -P) Centrifuge centrate (117 mg/l PO 4 -P) Treated with CeCl 3 at dose rates of: 50 ppm v for secondary clarifier effluent 3,000 ppm v for centrifuge centrate Unfiltered samples submitted for extraction testing via CalWET procedures 29

30 California WET Extraction Contaminants Secondary Clarifier Effluent Centrifuge Centrate Fluoride 0.91 mg/l 1.5 mg/l Inorganics: Sb, As, Ba, Be, Cd, Total Cr, Hex. Cr, Co, Cu, Pb, Hg, Mo, Ni, Se, Ag, Tl, V, Zn BDL BDL Pesticides BDL BDL Polychlorinated Biphenyls BDL BDL Herbicides BDL BDL Volatiles BDL BDL Bases/Neutrals/Acids (Semi-volatiles) BDL BDL 30

WISCONSIN WASTEWATER OPERATORS ASSOCIATION

Integrity. People. Knowledge. WISCONSIN WASTEWATER OPERATORS ASSOCIATION ANNUAL CONFERENCE GREEN BAY Resources. MEETING LOW LEVEL PHOSPHORUS LIMITS BY CHEMICAL ADDITION WHAT IS PHOSPHORUS Atomic # 15 Electron