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SUSTAINABLE MANAGEMENT OF TANNERY HAIR WASTE THROUGH COMPOSTING. ARTHUR ONYUKA. Overview. Background Aims and Objectives Why composting? Experimental Results and Discussion Concluding Remarks. Tanning process. Unhairing. Liming. Large amount of liquid and solid waste generated.
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SUSTAINABLE MANAGEMENT OF TANNERY HAIR WASTE THROUGH COMPOSTING ARTHUR ONYUKA
Overview • Background • Aims and Objectives • Why composting? • Experimental • Results and Discussion • Concluding Remarks
Tanning process Unhairing Liming • Large amount of liquid and solid waste generated. • Main cause for environmental concern. Bovine hide Beamhouse process
Solid waste arising • Fleshing and fats • Solid hair • Trimmings • Sludge Characteristics of beamhouse solid waste: Wet end 2% Tanning 17% Finishing 1% Beamhouse 80% Total = 700 kg Source: Puntener, A. (1995). JALCA, 90: 206
Disposal Landfill Land spreading Dumping Biological Composting Anaerobic digestion MBT Disposal and Treatment options Treatments Thermal • Incineration • Pyrolysis • Gasification
Environmental concerns • Green House Gas emissions. • Risk of global warming. • Health risks • Risk of water pollution. • Health risks • Non-sustainable use of land and loss of resources. Landfill disposal
Legislation • Legislation • Integrated Pollution Prevention & Control 96/61/EC - aim to prevent and reduce pollution caused by production. • Waste Framework Directive 75/442/EEC - sets out key objectives based on a hierarchy of options. • Landfill Directive 99/31/EC - sets targets for the reduction of biodegradable wastes sent to landfill.
Waste minimisation strategies • Based on Waste Framework Directive 75/442/EEC. • Forms key part of BAT
Key Aim Sustainable management of tannery hair waste through composting. Key Objectives Identify suitable biological treatment to enhance hair degradation. Develop favourable conditions for composting of hair waste. Aims and Objectives
Why composting? • Environmentally acceptable. • Stabilised product • Valuable product for the market. • Hair contains about 15% nitrogen • Ability to utilise the bulk of hair. • Inexpensive and adaptable
Potential Markets B A C • Agriculture • Landscaping • Sport turf
Understanding composting • Biological process Heat water CO2 Compost pile Composted organic material Oxygen Raw materials
Composting vessels Static process Drum process
Analyses • Microscopy: light & scanning electron microscopy (SEM). • pH: electrochemical method. • Moisture (% RH).
Analyses • Nitrogen: Total Kjeldahl Nitrogen Method. • Biochemical Tests: Folin-Lowry method, Gram staining, selective culture media. • Carbon: weight loss on-ignition of dry sample @ 560C then cooling to constant weight(% Carbon = Organic matter x 100/1.8).
Microbial properties Crude Microbes: on keratin azure Purified: optimum pH 2 1 Blank Treated Treated 3 4 Collagen hydrolysed Inhibition
Microbial degradation of hair Intact hair Hair degradation 5 6 (Mag. X400, 5.0kV) 7 (Mag. X600, 5.0kV) (Mag. X1.0K, 5.0kV)
Composting parameters • Compost achieved self-buffering at pH 7.0 and 8.0 • Average temperature maintained @ 49C • Thermal destruction of pathogens @ > 55C
Composting parameters • Supports microbial activity • Must be balanced to allow oxygen transfer. • Excessive: anaerobic process • Average moisture: 55%RH
Structural modification Control: 15 days Treated: 15 days 9 8 (Mag. X800, 5.0kV) (Mag. X800, 5.0kV) 10 11 60 days (Mag. X600, 5.0kV) 60 days (Mag. X600, 5.0kV)
Final products Control: 120 days Treated: 120 days 13 12 (Mag. X300, 5.0kV) (Mag. X600, 5.0kV) 14 15 Compost sample (Mag. X40, 5.0kV) Compost sample (Mag. X40, 5.0kV)
Final product • Dark and tacky • Nitrogen content: 1.4 - 1.5% per gram of sample. • Carbon content: 39 - 41% per gram of sample. 16 Product
Remarks • An environmental-friendly technology to manage tannery hair waste has been demonstrated. • Future merits includes: environmental and economic benefits through cost-saving and saleable product. • The decomposition of hair can be enhanced through the use of specific micro-organisms and optimisation of the environmental processing parameters.
Acknowledgements Dr. Paula Antunes Dr. Margaret Bates Prof. Geoff Attenburrow Prof. Anthony Covington Pat Potter (Mrs) Mandy Taylor (Ms) Tanya Hayes(Mrs) Annie Lama (Ms)