Invisible Odor Control

Transcription

1 2014 HDR Architecture, HDR, Inc., all rights reserved.

2 Invisible Odr Cntrl Cmbining Public Athletic Fields with Nutrient Equalizatin Basins and Hidden Odr Cntrl Systems Chris Easter, PE 2016 HDR, Inc., all rights reserved.

3 Backgrund and Purpse Carbn Change Out Plan Odr Characterizatin I&C Details Design Layut Details Dispersin Mdeling Verificatin Cnclusins

4 01 Backgrund and Purpse

5 Backgrund Alex Renew Wastewater Resurce Recvery Facility (WRRF) in City f Alexandria Va. Plant already had a centralized 200,000 cfm scrubber cmplex fr the WRRF Image prvided by FX FOWLE. This wrk added a Nutrient Management Facility (NMF) 18 mgal primary effluent flw equalizatin

6 NMF Site is just west f WRRF 18 mgals f tankage t stre primary effluent Allws diurnal nutrient peak shaving and mre cnsistent feed t bilgical treatment prcesses An athletic field is prvided n tp f the NMF fr public use Incrprates a hidden dr cntrl system View lking West

7 NMF 4 NMF Tanks 18 mgals 60,000 cfm dr ventilatin with 4 carbn scrubbers 3 ACH n ½ full tanks 300 fpm capture velcity n makeup air penings SST air pipe inside tanks Rigidly supprted against buyancy FRP air pipe utside tanks Each carbn unit fitted with dedicated VFD driven fans

8 02 Odr Characterizatin

9 Odr Characterizatin was based n field data frm existing primary settling tanks Sampling data Weir surface f primary effluent fr H 2 S and DT using flux hd Odalg hung in primary weir huse during August Jug head space sampling t check max Henry s equilibrium cncentratin Resulting Design cnditins Average annual H 2 S at 1 part per millin (ppm) with ccasinal sustained summer peaks t 5 ppm and ptential shrtterm peaks f up t 20 ppm. Mixtures f methyl mercaptan, dimethyl sulfide, and ther ptential rganic based reduced sulfur cmpunds ttaling less than 1 ppm. The dr cntrl system was designed t be able t treat these drs by prviding the fllwing perfrmance parameters: 99% reductin n H 2 S drs. 90% reductin in verall drs as measured by detectin threshld fllwing dr panel analysis using the American Sciety fr Testing and Materials (ASTM) E standard methd.

10 03 Design Layut Details

11 Prcess Overview 4 parallel dual bed carbn units Dedicated VFD driven fans Particulate screens befre each fan Access t tp f carbn via side drs Remte exhaust stack t prmte stack dispersin away frm the athletic field View lking West

12 Tp f the Field

13 Odrus air cllectin ductwrk is fitted with dampers and flw mnitring

14 Fan inlets with particulate filters

15 14 ft dual bed carbn units with dedicated fans Carbn bed pressure mnitring Fans prtected by pressure differential

16 Side entry fr carbn change uts

17 Tp access abve carbn Dual exhaust with dampers Remvable grating Large dr access t utside

18 Tp access Mnrails t handle super sacks

19 04 Carbn Change Out Plan

20 Carbn change uts Single use high capacity carbn blend T remve H 2 S and lw level rganic dr cmpunds Estimated change ut prjected fr 3 t 4 years Each bed has a VFD fan s if 1 f the 4 is dwn fr change ut the thers can treat mre flw 3 at 20,000 vice 4 at 15,000 cfm Als allws wner t turn dwn during lw dr perids and save hrsepwer Access drs have drive up access fr Vac trucks parked just utside Each carbn vessel can hld apprx. 925 cubic ft f carbn

21 05 I&C Details

22 Instrumentatin and Cntrls

23 06 Dispersin Mdeling Verificatin

24 Dispersin Mdeling T ensure the remte stack height was adequate Balance between ensuring dr cntrl and aesthetics f an versized exhaust stack next t the belt way Checked stack exhaust velcity and height required t prevent drs n the athletic field and nearby high rise buildings

25 Dispersin Mdel Set Up Exhaust stack 100 feet suth east f the new tanks Needed t d stack ptimizatin check

26 Selected an dr criteria cnsistent with ther applicatins 99.9% cmpliance 5 D/T 1-hur impact gal Cnsistent with past WRRF design which des nt receive dr cmplaints Reasnably cnservative cmpared t what thers have dne TABLE 2 Selected Odr Gals and Criteria in the United States fr Municipal Treatment Facilities Lcatin Bay Area Air Quality Management District (San Francisc Bay Area), Calif. Brightwater (Seattle, Wash.) WWTP Offsite Standard r Guideline Averaging Time and/r Frequency 5 D/T Applied after at least 10 cmplaints within a 90-day perid 5 D/T 5 minutes Cincinnati (Ohi) WWTP 7 D/T 3-minute average, 99% cmpliance Clrad Dublin San Ramn Services District, Dublin, Calif. 8 D/T (Scentmeter) Field measurement sustained 4 D/T 1-hur, 99% cmpliance Fairfax, Va. 7 D/T 1 hur, 100% cmpliance James River Plant, Hamptn Rads Sanitatin District, Virginia Beach, Va. Kentucky 5 D/T, 1-hur 10 D/T 3 minutes, 99% cmpliance 1 hur, 99.9% cmpliance 3 minutes, 99.9% cmpliance 7 D/T (Scentmeter) Field measurement Massachusetts 5 D/T 1 hur Missuri 7 D/T (Scentmeter) Field measurement Nevada 9 D/T 1 hur New Jersey 5 D/T 5 minutes r less Orange Cunty, Calif. 15 D/T 3 minutes San Dieg WWTP 5 D/T 5 minutes, 99.5% cmpliance Virginia Initiative Plant, Hamptn Rads Sanitatin District, Virginia Beach, Va. 2 D/T, 1-hur 7 D/T, 3-minute Wyming 7 D/T OU, dr unit. 1 hur, 100% cmpliance 3 minutes, 99.9% cmpliance

27 Stack Height Evaluatin Odr surce strength at the stack Assumed 300 DT in the exhaust air Design required 90% reductin r 150 DT max Used AERMOD with lcal MET data Reagan Airprt data

28 Stack height evaluatin Stack evaluatin shwed that a 25 ft stack was needed 50 ft prvided t stay abve the athletic fields and ensure minimal impact risk

29 N 5 D/T impacts predicted 1 DT impacts shwn fr perspective f ptential initial impact zne

30 07 Cnclusins

31 Cnclusins The new NMF and related dr cntrl systems have been cnstructed and tested shwing they meet the required perfrmance criteria. Althugh the facility is relatively new, t date n dr cmplaints have been received. The flexibility f the carbn systems with VFD driven fans has allwed AlexRenew t adjust the dr cntrl systems t a lwer pwer demand, saving cst, while still meeting the cmmitment t capture and treat drs preventing dr impacts t the public.

32 Questins?