Odor Control in Sewerage Systems of Lviv City
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This document discusses odor control in sewerage systems in Lviv, Ukraine. It summarizes Egis' work conducting a pre-diagnosis of odor problems in Lviv's sewerage system. Key outcomes included the need to implement an odor tracking system to identify odor sources and the finding that the sewerage system and wastewater treatment plant are likely major odor sources. The document then outlines Egis' methodological approach to diagnosing specific cases, including field inspections, monitoring, and hydraulic and water quality analyses to identify causes and appropriate treatment solutions.
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Odor Control in Sewerage Systems of Lviv City
- 1. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 1 Nov 19, 2015 ODOR CONTROL IN SEWERAGE SYSTEM ©Artefacto/IntrépideProductions-ArthurChays Methodological approaches and feedback experiences Lviv City Hélène PIET, Egis
- 2. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 2 Egis GROUP – Key Figures
- 3. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 3 €854 M OF MANAGED TURNOVER 78 % ENGINEERING22 % ROAD & AIRPORT OPERATION
- 4. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 4 53% OF SALES ABROAD 4% AMERICAS 47% FRANCE (incl. French Overseas Departments and Territories) 12% AFRICA 21% EUROPE 8% ASIA 1% AUSTRALIA OCEANIA 1% Ukraine 7% MIDDLE EAST
- 5. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 5 12,000 EMPLOYEES 12,000 employees TOTAL WORKFORCE ON DECEMBER 31, 2014 4,200 ROAD AND AIRPORT OPERATING COMPANIES STAFF 7,800 ENGINEERING DIVISION STAFF 4,100 FRANCE 3,700 INTERNATIONAL
- 6. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 6 EGIS UKRAINA. 20 YEARS OF CREATIVE WORK 55 employees 30 engineers 40 projects in Ukraine and CIS Key services: - feasibility study - mobility study - corporate development - technical support to the municipalities - construction supervision - project management 822 000 € – 2014 TURNOVER
- 7. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 7 KEY FIELDS OF OPERATIONS IN UKRAINE Urban transport Roads Water Energy New tramway produced in Lviv for the LvivElectrotrans modernisation project led by EGIS
- 8. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 8 PRE-DIAGNOSIS OF ODOR PROBLEMS IN THE SEWERAGE SYSTEM OF LVIV CITY
- 9. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 9 CONTEXT • Citizen’s complaints for bad smells • Lviv, tourist capital of Ukraine
- 10. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 10 SCOPE OF WORK • General and preliminary assessment of smell problem • Define technical solutions or propose further investigations to understand smell problems
- 11. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 11 MAIN OUTCOMES (1) Odor complaints spread over a large area No systematic recording and follow-up regarding these complaints Implement an Odor tracking system/service • Find the origin • Warn LVK of any abnormal situation • Keep track of the evolution of odor situation Chapitre
- 12. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 12 MAIN OUTCOMES (2) Sewerage system seems to be the main odors source in several districts => To implement an hydraulic diagnosis and technical solutions, on a case by case basis WWTP and sludge deposit area have a large emissivity and could instigate complaints under specific wind conditions => To implement an olfactometric measurements campaign to identify main odor sources and prioritize technical solutions Chapitre
- 13. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 13 FIRST STEP / IMPLEMENTING AN ODOR TRACKING SYSTEM
- 14. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 14 LVIV ODOR MAP Chapitre
- 15. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 15 EXEMPLE OF SIAAP - PARIS (1) Report a complaint on the website : Odor statement Date Hour Town Adress Duration Less than an hour A few hours 1 to 2 days Several days Kind of smell Level of annoyance Level of Intensity Remarks I wand to be contacted :
- 16. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 16 EXEMPLE OF SIAAP - PARIS (2) In-field odor inspections 4 inspectors from SIAAP Daily patrols in-site and in the environment of facilities Paths and check points determined on a weekly and daily basis according : - Citizens complaints - Maintenance works - Trials and study about technical solutions or preventive works to reduce odor emissions
- 17. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 17 FOLLOW-UP OVER THE YEAR Jan. Feb. March April May June July August Sept. Oct. Nov. Déc. Year 2014 High H2S level at pumping station 4 Maintenance work on collector 6 Stopping the deodorization plant for maintenance + propitious weather conditions : Situation olfactive satisfaisante : Situation olfactive passable : Situation olfactive médiocre : Situation olfactive critique
- 18. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 18 SEWERAGE SYTEM Diagnosis and technical solutions on a case by case basis
- 19. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 19 METHODOLOGICAL APPROACH pressure pipe gravity pipe junction chamber vent 1- Where does the odor come from ? Residential area Industrial collector Industrial collector in-field odor inspections H2S continuous monitoring
- 20. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 20 METHODOLOGICAL APPROACH pressure pipe gravity pipe junction chamber vent Residential area Industrial collector Industrial collector 2- Understanding the causes Measurements campaign of: water flow rate + H2S concentrations + temperature, BOD5/COD, pH, over an extended period of time Retention time to check Is the vent high enough ?
- 21. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 21 METHODOLOGICAL APPROACH pressure pipe gravity pipe junction chamber vent Residential area Industrial collector Industrial collector 2- Understanding the causes Hydraulics characteristics : Water flow rate Water velocity Diameter changes Slopes changes Turbulence, confluence of major tributary systems Manhole locations Measurements campaign of: H2S concentrations in headspace Water quality = Sulfates (SO4--), pH, dissolved and total sulfides, sewage temperature, BOD5/COD, suspended solid, Pressure in the headspace Structural conditions of the collector Failures inspections Maintenance man hole sealing
- 22. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 22 HEADSPACE CONSTRICTION Chapitre Downstream sewer cannot accept all of the upstream air causing out venting off the sewer Lowvelocity water pushes back on fast moving air causing a pressure zone to form upstream Hydraulic jumps can also constrict airspace causing more backpressure
- 23. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 23 CLASSICAL LIQUID PHASE TREATMENT (1) Iron salts addition H2S curative application Chapitre
- 24. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 24 CLASSICAL LIQUID PHASE TREATMENT (2) Calcium Nitrate H2S preventive application Chapitre
- 25. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 25 OTHER INVESTIGATIONS / SOLUTIONS Chapitre Odor tracking system Control the proper design and hydraulics characteristics Control the maintenance Control of wastewater entry - Industrial and non-domestic waste water surveys, hauled waste station to implement Inhibition of H2S (nitrate, oxygen injection…) Collection of air (gaz trap on rain gullies, ventilating facilities) and treatment
- 26. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 26 www.egis-group.com H élène PIET A rnaud D E R U GY A i r / O d o r E x p e r t R e g i o n a l M a n a g e r f o r U k r a i n e a n d C I S H e l e n e . p i e t @ e g i s . f r A r n a u d . D E R U G Y @ e g i s . f r , Т e l . + 3 8 0 4 4 2 4 6 6 4 4 8 CONTACT
- 27. EGIS, CREATIVE FOR THE LONG TERM JULY 2015 27 Chapitre
Editor's Notes
- Goodafternoon everybody. My name is Helen Piet from Egis Group I’m gonna talk today about odor control in sewerage system. We will see methods approachs and feedback experiences that we have in Lviv and other cities If there is confusing during the talks please to feel free to interrupt me to ask a question
- Let me first show you some key figures about Egis Group
- Egis Group is a French company. The group is specialized in engineering in the field of transportation, water and environment. Egis is also involved in the business of setting up projects and operations for roads and airports
- Rajouter des éléments sur Egis Ukrain
- Egis Group has about 12 000 employees. A large majority is engineering staff
- The reason of my presence here today is because very recently we have performed a study about odor problems in Lviv City
- Many citizen’s complaint for bad smells. And you have to realize that Lviv is a very touristic city in Ukrain. So it is important to do something because Lviv is a very touristic city in Ukrain, it is important for Lviv to keep a good environmental image. Between april to july 2014 : more than 50 complaints /month Between July to september 2012 : more than 300 complaints/month. In this period Lviv was one of the venues for the UEFA Euro 2012.
- The scope of work can be summarize as follow. First we have to.. Once this is done/after that, we must define technical solutions or propose further…
- The main outcomes are the following. Odor complaints are spread over a large area, as you can see in this map. This map is from a website implemented by a citizen of Lviv, by its personnal initiative. It represents odor complaints over one specific day. People go on the website and they can declare (They answer a few questions) if there is an odor or not and if it’s really stink or not. An from all these answers, automatic map is generated/ This map represent these answers Between april to july 2014 : more than 50 complaints /month Between July to september 2012 : more than 300 complaints/month. In this period Lviv was one of the venues for the UEFA Euro 2012.
- This study and especially my observations tends to show that the sewerage system seems to be the main odors source. Why ? Because in some streets, odor are restricted/localized to the small area along the street and the collector. Located around.
- 5 levels scale On a scale to 1 to 5 you have to define Phone numer : not complusory. It’ optionnal. From these data, a report is made on a daily basis and then a weekly basis. In ordre to undesrtand the problem ad then to solve the problem.
- Thses inspectors are people that every day do watch, patrols Determiiiined
- Finir les animations
- Finir les animations Let me show you what we can fo to undesrtand the causes. How we do that ?
- Finir les animations
- Expliquer que LVK a déjà implementer cette solution Iron salts solution Reacts with dissolved sulfides in water by the following summary reaction: 2FeCl3 + 3H2S ‡ S_ + 2FeS_ + 6HCl Applying a dosage beyond that dose required for initial H2S removal, Ferric Chloride then reacts to form Ferric Hydroxide which is a coagulant/ flocculant. The result is enhanced settling of both the generated sulfide removal solids and other wastewater Iron Salts (Ferric and Ferrous) Iron Salt Applications Iron salts are a proven technology for long-duration hydrogen sulfide control in collection system gravity and forcemains, solids processing units, solids transfer lines and anaerobic digesters. They have been used for over 30 years in hydrogen sulfide control applications and are a well understood technology. Depending on the wastewater plant unit process configuration, iron salts may also provide improvements in clarification, phosphate removal, struvite control, solids dewatering and anaerobic digester performance. Iron salt performance is not impacted by oxygen uptake rates but they do remove dissolved oxygen from the water. Iron Salt Properties and Dosing Iron salts are supplied as liquid solutions containing 5-13% ferrous or ferric iron as either a chloride or sulfate salt. They are supplied in containers of 55 or 300 gallons, or in bulk shipments of 4,000 - 20,000 gallons. Iron salts bind with hydrogen sulfide according to the following equations: Ferrous Salts: H2S + FeCl2 → FeS + 2HCl Ferric Salts: 3 H2S + 2 FeCl3 → S + 2 FeS + 6 HCl Theoretical dose ratios of ferrous iron to H2S are 1.75 lbs Fe2+:lb H2S with practical dose rates anywhere from 2 to 6 depending on the application. Theoretical dose ratios of ferric iron to H2S are 1.2 lbs Fe3+:lb H2S with practical dose rates anywhere from 1.5 to 4 depending on the application. Iron Salt Pricing and Sources Iron salt pricing is highly regional and dependent on the local sources and demand for the product. Iron salts for sulfide control are mostly obtained from spent pickle liquor from the steel industry. More recently, newer sources have been manufactured from scrap materials and acid in order to meet regional demand. Iron Salt Drawbacks Some drawbacks of iron salt use are as follows: Removes dissolved oxygen from the water Precipitate settles out in low-velocity sewers (< 2 fps) Iron films form on pipe walls and instrument sensors Ineffective for (non-sulfide) organic odors Hard to achieve low sulfide limits (pH dependent) Does not destroy sulfide (H2S may volatilize if the pH is lowered) Product purity may impact biosolids re-use (heavy metal contamination) Messy to handle CERCLA rating may restrict dosing sites (persistent environmental hazard) High dosages may cause solids carry-over from clarifiers Solids production (> 3 lbs/lb - Sulfide) increases processing and disposal costs
- Nitrate Applications for Hydrogen Sulfide Control Nitrates are a proven technology for medium to long-duration hydrogen sulfide control in collection system gravity and force mains. They have been used for over 15 years in hydrogen sulfide odor control applications and are a well understood technology. Nitrates can be used in certain applications where hydrogen sulfide odor is already present (curative) or to prevent the formation of hydrogen sulfide (preventative) odor. Curative Applications Nitrates react mainly in the water column providing electrons for oxidation. In the curative application mode, a minimum retention time of 2-3 hours is required in order to be effective. In the preventative mode, nitrates condition the biofilm for anoxic process, preventing sulfate from being reduced to hydrogen sulfide in anaerobic sewer conditions. Preventative Applications A minimum retention time of 3 hours is necessary in order to be effective. When applied properly, control to low hydrogen sulfide levels is possible. Bioxide may provide some in-line BOD reduction in the collection system. Most calcium and sodium nitrate formulations are considered a non-hazardous material and can be stored in simple feed systems. Nitrate Properties and Dosing Nitrate is available as either in either granular or liquid form, and either as a calcium or sodium salt. The granular product comes in 100-lb bags, 2000-lb supersacks, or bulk hopper cars. The liquid product is the more commonly used form, and is available in bulk shipments of 2,000 - 4,000 gallons. Typical calcium nitrate formulations contain 4.3 lbs NO3 per gallon of solution. Typical sodium nitrate formulations contain 3 lbs NO3 per gallon. Nitrates prevent or remove hydrogen sulfide according to the following equations: Curative (Biomediated Oxidation): 5 H2S + 8 NO3 → 5 SO42- + 4 N2 + 4 H2O + 2 H+Prevention: 8/5 NO32 + [2 O2] (approximate representation)Theoretical dose ratios in the preventative mode of nitrate to H2S are 2.6 lbs NO3:lb H2S. Practical preventative dose rates for calcium nitrate vary anywhere from 2 to 8 gallons per pound H2S depending on the application. Theoretical dose ratios in the curative mode of nitrate to H2S are 0.7 lbs NO3:lb H2S. Practical curative dose rates for calcium nitrate vary anywhere from 1 to 2 gallons per pound H2S depending on the application. Nitrate Pricing and Sources The most common form of nitrate on the market for hydrogen sulfide control is liquid calcium nitrate solution. Typical pricing for calcium nitrate solutions is $2.00 to $2.50 per gallon. In the preventative mode, the cost per pound of sulfide treated is anywhere from $4.00 to $20.00. In the curative mode, the cost per pound of sulfide treated is anywhere from $2.00 to $5.00. Nitrates for sulfide control are mostly obtained from fertilizer manufacturers. Nitrate Drawbacks Some drawbacks of nitrate use are as follows: Inefficient for gravity lines Increases nitrogen levels in the wastewater Resultant N2 gas (or residual NO3) may present problems downstream at the wastewater plant Costs for prevention mode may be excessive in long retention time lines Biomediated oxidation mode may require several hours, making nitrates less effective in certain applications (e.g. manifolded force mains) Costs may be high in applications with high oxygen uptake rates (higher temperature, etc...) Costs for prevention mode impacted by high BOD levels Note: The use of nitrates for the removal of odors present at the point of addition (biomediated oxidation mode) may be covered under US Patent.