1 SPECIALIZED ENGLISH – SEMESTER 5 VAN LANG UNIVERSITY DEPARTMENT OF ENVIRONMENTAL TECHNOLOGY AND MANAGEMENT Chapter 3Chapter 3 FUNDAMENTALS OF BIOLOGICAL FUNDAMENTALS OF BIOLOGICAL Dr. Tran Thi My Dieu Sep. 2011 VAN LANG UNIVERSITY DENTEMA SOLID WASTE TREATMENTSOLID WASTE TREATMENT COMPOSTING CONTENTSCONTENTS Why compostingWhy composting Compost qualityCompost quality VAN LANG UNIVERSITY DENTEMA Process factorProcess factor Process technologyProcess technology WHY COMPOSTINGWHY COMPOSTING Advantages Simple system Emissions Disadvantages LandfillingLandfilling VAN LANG UNIVERSITY DENTEMA Easy operation Versatile Cheap Landscape decline Odour hindrance Difficult to plan Loss of resource WHY COMPOSTINGWHY COMPOSTING Transforms waste in to compostTransforms waste in to compost WA STE COMPOSTING LANDFILL VAN LANG UNIVERSITY DENTEMA COMPOSTING COMPOST AGRICULTURE GARDENING ? Wastes in to compost chain is feasible only ifWastes in to compost chain is feasible only if Compost quality meet farmers demandCompost quality meet farmers demand COMPOST QUALITYCOMPOST QUALITY Contaminants Nutrients VAN LANG UNIVERSITY DENTEMA Pathogens Stability & organic matter Product quality 1= free of contaminants Non-compostables Glass COMPOST QUALITYCOMPOST QUALITY Chemicals H e a vy m e tal s VAN LANG UNIVERSITY DENTEMA Stones Plastic evy e s Chemical waste Pesticide residues 2 Management of contaminantsManagement of contaminants Waste separation at source hhld COMPOST QUALITYCOMPOST QUALITY Mechanical Separation  sieves VAN LANG UNIVERSITY DENTEMA  h ouse h o ld  markets  Industry  sieves  magnetic  density Composting: PAH Product quality 2 = nutrients Macro nutrients: N, P, K, S, availability Micro nutrients: Cu, Zn, etc., heavy metals COMPOST QUALITYCOMPOST QUALITY VAN LANG UNIVERSITY DENTEMA Desired Level depends on Application Product quality 3 = free of pathogens H man animal & plant all of concern COMPOST QUALITYCOMPOST QUALITY Free = sufficient low level to prevent contamination VAN LANG UNIVERSITY DENTEMA H u man , animal & plant all of concern Sanitation is effect of: Temperature Moisture Oxygen Product quality 4 = stability Stability = sufficient low level of aerobic activity under standardized conditions of Tem p erature COMPOST QUALITYCOMPOST QUALITY VAN LANG UNIVERSITY DENTEMA p Moisture Oxygen Stability < or = to standard Odour Regrowth of pathogens Plant disease Supression Aiffi WHY STABILITYWHY STABILITY VAN LANG UNIVERSITY DENTEMA A ttract i on o f f l i es Prevention of oxygen depletion in growing media Structural stability in growing media Damage to the root is damage to the plant COMPOSTING WA STE Off-gas COMPOSTING PROCESSCOMPOSTING PROCESS VAN LANG UNIVERSITY DENTEMA PRE-TREATMENT POST-TREATMENT COMPOST AIR 3 Composting: basic representation OM + O 2 > CO 2 +H 2 O + heat Microbial Reaction Oi lP COMPOSTING PROCESSCOMPOSTING PROCESS VAN LANG UNIVERSITY DENTEMA O pt i ma l P rocess ==> Optimal Conditions for Microbes Process conditions C/N ~ 25/1 T ~ 45-55 o C optimum O ~>5% COMPOSTING PROCESSCOMPOSTING PROCESS VAN LANG UNIVERSITY DENTEMA O 2 ~ > 5% H 2 O ~ 40-60% Bulk Density ~ 450-600 kg/m 3 Process conditions COMPOSTING PROCESSCOMPOSTING PROCESS VAN LANG UNIVERSITY DENTEMA FUNCTION pre-treatment Optimize material conditions for composting Structure: wood, branches etc. COMPOSTING PROCESSCOMPOSTING PROCESS VAN LANG UNIVERSITY DENTEMA Dry matter Windrow aeration COMPOSTING PROCESSCOMPOSTING PROCESS VAN LANG UNIVERSITY DENTEMA Air VAN LANG UNIVERSITY DENTEMA Seattle Tilth Composting Demonstration Site 4 VAN LANG UNIVERSITY DENTEMA VAN LANG UNIVERSITY DENTEMA Aerated static pileAerated static pile Air COMPOSTING PROCESSCOMPOSTING PROCESS VAN LANG UNIVERSITY DENTEMA Air Blower Composting process COMPOSTING PROCESSCOMPOSTING PROCESS VAN LANG UNIVERSITY DENTEMA Composting process Odor control critical Environmental influence Litt COMPOSTING PROCESSCOMPOSTING PROCESS VAN LANG UNIVERSITY DENTEMA L ower i nves t men t Average rate needed Low maintenance Low skills Aeration Cycle: OFF 10 minutes; ON 5 minutes c ent 20 25 55 60 65 70 Pile T Blower OFF Oxygen Percent Temperature feedback controlTemperature feedback control COMPOSTING PROCESSCOMPOSTING PROCESS VAN LANG UNIVERSITY DENTEMA Minutes Pile Oxygen Per c 0 5 10 15 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 15 20 25 30 35 40 45 50 T emperature (°C) Blower ON Pile Temperature 24 Source: Phil Leege 5 VAN LANG UNIVERSITY DENTEMA VAN LANG UNIVERSITY DENTEMA Agitated-bed strategy Manure Com post Feedstock COMPOSTING PROCESSCOMPOSTING PROCESS VAN LANG UNIVERSITY DENTEMA Manure In Com post Out Air In VAN LANG UNIVERSITY DENTEMA COMPOSTING PROCESSCOMPOSTING PROCESS VAN LANG UNIVERSITY DENTEMA Air photo composting plantAir photo composting plant Open heap compostingOpen heap composting COMPOSTING PROCESSCOMPOSTING PROCESS VAN LANG UNIVERSITY DENTEMA Box/container compostingBox/container composting Drum, with artificial Drum, with artificial aeration systemaeration system 6 VAN LANG UNIVERSITY DENTEMA FUNCTION post-treatment Particle size Removal unwanted components COMPOSTING PROCESSCOMPOSTING PROCESS VAN LANG UNIVERSITY DENTEMA (stone, g lass, plastics) Mixing with other materials (manure, peat) . LANG UNIVERSITY DENTEMA Minutes Pile Oxygen Per c 0 5 10 15 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 15 20 25 30 35 40 45 50 T emperature (°C) Blower ON Pile Temperature 24 Source: Phil. SEMESTER 5 VAN LANG UNIVERSITY DEPARTMENT OF ENVIRONMENTAL TECHNOLOGY AND MANAGEMENT Chapter 3Chapter 3 FUNDAMENTALS OF BIOLOGICAL FUNDAMENTALS OF BIOLOGICAL Dr. Tran Thi My Dieu Sep. 2011 VAN. PROCESSCOMPOSTING PROCESS VAN LANG UNIVERSITY DENTEMA PRE-TREATMENT POST-TREATMENT COMPOST AIR 3 Composting: basic representation OM + O 2 > CO 2 +H 2 O + heat Microbial Reaction Oi lP COMPOSTING