Evaluation of Gaseous and Bioaerosol Emissions from Compost Facilities Comparing Three Feedstocks: SSO, Dairy manure and Deadstock

Transcription

1 Evaluation of Gaseous and Bioaerosol Emissions from Compost Facilities Comparing Three Feedstocks: SSO, Dairy manure and Deadstock Geneviève Marchand Ph. D. microbiologist, biochimist IRSST et Yves Bernard, engineer CRIQ 26 th Annual National Organics Recycling Conseil Canadien du Compost Niagara Falls, Ontario 26 septembre 2016

2 Introduction The whys of the project Government's new politics on organics wastes valorization lead to the increases of Composting activities Number of workers involved in green jobs Knowledge To take place Compost needs various microorganisms Bacteria, fungi, actinomycetes Produces many gaseous substances Gaps Worker s exposition to microbes and gases

3 Introduction The whys of the project-2 Importance of workers exposition documentation Bioaerosols and gaseous compounds exposition may cause health problems Health effects will depends: Chemicals Biologicals Concentrations Aerodynamic diameter (size)

4 Introduction Objectives Main objective: Compare the concentrations of bioaerosols, dusts particles and gaseous compounds found in the air surrounding three different types of composting facilities in order to estimate a plausible health risk to the workers

5 Introduction Objectives Secondary objective: Evaluation of bioaerosols, gaseous compounds and dust concentrations Evaluation of the potential use of microbial indicators to do health risk estimation Identification of the composting parameters and the working methods that results in the smallness worker s exposition

6 2 Materials and methods Sites

7 Types of residues and differences between each process Site Type of matter SSO (Municipal) Dairy manure Pig Carcass Duration 21 days 2 months 7 months Type of aeration Number of mixing Time of mesure Continuous 24 h / 24 1) 9 to 29 April (end of winter) 2) 29 july to 19 aug. (summer) Continuous 24 h / 24 Natural Spring to summer Two times 1) 11 june to 27 march 2) 30 sept to may 2013

8 1) Municipal composting SSO (sources separated organics) 4 steps : 1) Reception, 2) bags sorting, 3) tunnel composting, 4) compost refinement Manual sorting room to clean compost : bags Mecanical wall push compost at each day to the output; Loader pick up compost in the output of tunnel;

9 2) Composting of dairy manure 4 steps of composting: Accumulation and stocking of fresh manure; Phase 1 of thermophilic composting during 4 weeks; continuous aeration of compost and mixing with loader; Phase 2 of of thermophilic composting during 4 weeks; continuous aeration of compost and mixing with loader; Maturation of compost during 1 to 4 months (static);

10 3) Deadstock Composting of pigs mortalities in a maternity piggeries Carcass and animals residues Composting (non mecanical aeration) 6 steps o Phase 1 : Accumulation of mortalities and filling of the unit ; duration 1 month; mixing with a comb (metal rods); o Phase 2 : Displacement from cell 1 to cell 2 and mixing; o Phase 3 : Composting during 3 months; o Phase 4 : Displacement from cell 2 to cell 3 and mixing; o Phase 5 : Composting during 3 months; o Phase 6 : Maturation outside;

11 2 Materials and methods Sampling

12 Composting process : sampling for solid matter Physico-chimical analysis Sampling at each step of composting : composite sample with ten subsamples of 10 L min. between each subsample mixing of 100 L for a 20 L sample bring to laboratory each analyze is made in duplicata or triplicata Temperature and O 2 Ten points in each piles and two depth (30 cm and 1 m from the surface)

13 2 Materials and methods Compost

14 Composting process : Parameters - Moisture content; - Organic matter; - Total Nitrogen; - C/N ratio; - Density; - ph - Respiration rate O2 - Temperature; - O 2 - Aeration rate; - Mixing schedule;

15 Results 2 Compost

16 Abstract : Analysis of solid during composting process Parameters Optimum value 1) SSO 2) Dairy manure 3) Deadstock Temperature ( C) 50 to 60 About 60 Stock : 20 to 30 Oxygen O 2 (%) More than 5 % Batch 1 : 13 % Batch 2 : 5 % Density (kg/m 3 ) Less than 700 kg/m3 Batch 1 : 470 Batch 2 : 515 Moisture content between Batch 1 : 50 % Wet basis (%) 40 et 60 % Batch 2 : 45 % Nitrogen dry basis (%) C/N ratio ph Respiration rate (mg O 2 / kg m.o.-h) between 25 to 35 Between 6 to 8 Mature Compost : less than 400 Batch 1 : 1 to 2 % Batch 2 : 1,9 to 1,7 % Batch 1 : 25 to 14 Batch 2 : 17 to 15 Batch 1 : 7,4 Batch 2 : 6,5 B1 : to B2: to About 60 Batch 1: 59 to 53 Batch 2 : 64 to 43 About 5 % Batch 1 : 10 to 15 Batch 2 : to to 400 Batch 1 : 75 to 65 Batch 2 : 70 Batch 1 : 3 to 1,5 Batch 2 : 2 to 3 Batch 1 :15 25 Batch 2 : 15 5? Batch 1 : 8 to 9 Batch 2 : 9 B1 : to 800 B2 : 500 to About 50 % 3 to 4,5 % 10 to 15 Batch 1: 5,5 to 6 Batch 2 : 6 to 7 B1 : B2 : to 4 700

17 2 Materials and methods Air

18 The contaminants Bioaerosols bacteria fungi actinomycetes Dust Gases Nitrogen dioxide NO 2 Nitrogen monoxide NO Hydrogene sulfide H 2 S Carbone monoxide CO And dioxide CO 2 Ammonia NH 4 Nitrous oxide N 2 0 Methane CH 4 Volatile organic compound

19 Bioaerosols COMPOSTING PLANTS (3) Coriolis µ 300 L/min -10 min UV-APS 5 L/min 1 min Direct reading of particles Fluorescent = bioaerosols Non fluorescent = totale Andersen impactors 28.3 L/min 2 min Growth culture Bacteria Fungi Actinomycetes Aspergillus fumigatus Biodiversity by sequencing (DNA) Molecular detection by qpcr (DNA) Bacteria (universel primer) Penicillium/Aspergillus Asprgillus Fumigatus S. Rectivirgula Mycobacterium spp Legionella spp Legionella pneumophila

20 Bioaerosols: UV-APS COMPOSTING PLANTS (3) UV-APS 5 L/min 1 min Direct reading of particles Fluorescent = bioaerosols Non fluorescent = totale

21 Bioaerosols: Cultivable Molds COMPOSTING PLANTS (3) Andersen impactors 28.3 L/min 2 min Growth culture Bacteria Fungi Actinomycetes Aspergillus fumigatus Bacteria

22 Bioaerosols COMPOSTING PLANTS (3) Molecular detection by qpcr (DNA) Coriolis µ 300 L/min -10 min

23 Endotoxin, Dust and Gases COMPOSTING PLANT (3) PVC filter pre weight 2 L/min 120 min Dust photoacoustic spectroscopy Nitrous oxide N 2 O Ammonia NH 3 MX6 ibrid Direct reading Nitrogen dioxide NO 2 Nitrogen monoxide NO Hydrogene sulfide H 2 S Carbone monoxide CO And dioxide CO 2 Volatil organic compound VOC Methane CH4

24 2 Results Air Bioaerosols

25 SSO deadstock manure Working impacts Bacteria Molds A fumigatus Background Working Actinomycetes The concentrations of microorganisms increases during working activities

26 Bioaerosols (recommended exposure limits) Bacteria CFU/m 3 Mold (fungi) CFU/m 3 Actinomycetes (thermophile) Aspergillus fumigatus Endotoxins CFU: Colony forming unit EU: Endotoxin unit Not available Lowest as possible achievable Relative limit value 150 EU/m 3

27 tri lot 1 tunnel lot 2 tri lot 1 tunnel lot 2 build up stirring 1 build up stirring 2 stirring 1 stirring 2 spreading spreading build up lot 1 stirring 1 lot 1 stirring 2 lot 1 build up lot 2 stirring 1 lot 2 stirring 2 lot 2 maturation lot 1 Bacteria: Threshold of UFC/m 3 of air Bacteria cultivables 1.80E E E E E E E E E E+00 SSO Manure Deadstock

28 tri lot 1 tunnel lot 2 tri lot 1 tunnel lot 2 build up stirring 1 build up stirring 2 stirring 1 stirring 2 spreading spreading build up lot 1 stirring 1 lot 1 stirring 2 lot 1 build up lot 2 stirring 1 lot 2 stirring 2 lot 2 maturation lot 1 Mold: Threshold of UFC/m 3 of air 2.50E E+05 Mold cultivables The concentrations of bacteria and molds change in the time 1.50E E E E+00 SSO Manure Deadstock The concentrations of bacteria and molds are higher than the recommended limits

29 Microbial Risk indicators- Molecular biology Potential indicator of health risk in composting facilities Mycobacterium spp Legionella spp Legionella pneumophila Sacchopolyspora rectivirgula Aspergillus fumigatus Aspergillus et Penicillium Specific DNA probes use to do the detection

30 triage maturation triage maturation initiation brassage 1 brassage 2 épandage initiation brassage 1 brassage 2 épandage initiation brassage 1 brassage 2 initiation brassage 1 brassage 2 maturation Microbial Risk indicators- Molecular biology 5.00E E E E E E SSO CR Not always present LP Manure 2 1 ND Deadstock 2 3

31 triage maturation triage maturation initiation brassage 1 brassage 2 épandage initiation brassage 1 brassage 2 épandage initiation brassage 1 brassage 2 initiation brassage 1 brassage 2 maturation Microbial Risk indicators- Molecular biology 4 possible microbial risk indicators 5.00E E E E E E+01 1 SSO CR 2 1 LP Manure Legionella pneumophila (LegMip) Legionella spp (LEG) Aspergillus fumigatus et Neosartoria fischeri (Afumi) S rectivirgula (Sac) Deadstock ND 3

32 Bioaerosols resume The concentrations of microorganisms increases during working activities The concentrations of microorganisms varies in time The concentrations of bacteria and molds are higher than the recommended limits 4 possible microbial risk indicators

33 Results 2 Air Gaseous compounds

34 Exposure limits for gaseous compounds

35 Exposure limits for gaseous compounds 1% Manure Manure Methane and Ammonia are the only gases measure at the limits

36 2 Results Compost parameters and contaminants relation

37 ph vs microorganismes 7 A 8 B A ph Molds culture (A) r 2 : ph Aspergilllus fumigatus (B). : r 2 :

38 ph vs chemical compounds A B ph Ammonia (A) r 2 : ph Dust (B) r 2 :

39 Water content Moisture content w.b. (%) Molds by molecular biology r 2 : Moisture content w.b. (%) Dusts r 2 :

40 Conclusion Working on the compost produce aerosolization of microorganism in the air Few gases have been measured The exposition is variable in time and between the composting facilities

41 Conclusion Proposed exposure limits are often exceeded for cultivable bacteria and molds Presence of pathogenic microorganisms is confirm Mycobacterium, Legionella spp, A. fumigatus Microbial risk indicators could be used to help document the workers exposition

42 Conclusion ph and water content have a negative relation with the molds concentrations and the level of dusts Microbial growth have an influence on the ph Molds are favored when ph is more acid ph have a positive relation with ammonia Low ph produce more Ammonia

43 The limits Only three facilities were evaluated The sampling site could not be near the breading zone of the workers

44 Recommandations Since concentrations of microorganisms measured in the air near the compost are sometimes more than 10 times the recommended limits Use of a respirator for specifics tasks is recommanded Since the exposition time is short and most workers are at a distance of the emission, a protection factor of 10 could be adequate. Ex: N95 respirator But higher protection may be needed sometimes

45 Research team Genevieve Marchand (IRSST, UdeM) Yves Bernard (CRIQ) Caroline Duchaine (CRIUCPQ, U Laval) Yves Cloutier (IRSST) Jacques Lavoie (IRSST, UdeM) Marc Veillette (CRIUCPQ) Laetitia Bonifait (CRIUCPQ) Collaborateurs et étudiants Carole Pépin (IRSST) Yves Beaudet (IRSST) Éric Légaré (CRIQ) Daniel Pelchat (U. Trois rivières) Hamza M Bareche (U. laval) Marie-Eve Dupuis (U. laval) Maude Talbot (U. laval)

46 Publications Rapport IRSST Évaluation des bioaérosols et des composés gazeux pendant le compostages de résidus agroalimentaires et résidentiels Evaluation Marchand et al. Scientific paper Workers exposure to bioaerosols from three different types of composting facilities" Journal of Occupational & Environmental Hygiene Submitted: Laetitia Bonifait et al. Preferential aerosolization of bacteria in the air of different composting plant In preparation: Laetitia Bonifait et al.