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Food Industrial Waste Engineering BIOLOGICAL AND PHYSICAL TREATMENT OUTLINE Processing waste Fruit and vegetable waste Meat and poultry products waste Dairy products waste Fish and seafood product waste Food packaging waste Biol...
Food Industrial Waste Engineering BIOLOGICAL AND PHYSICAL TREATMENT OUTLINE Processing waste Fruit and vegetable waste Meat and poultry products waste Dairy products waste Fish and seafood product waste Food packaging waste Biological Treatment WHAT IS THE MOST ABUNDANT WASTE DURING PROCESSING & FOOD INDUSTRY? IS THIS WASTE FROM PROCESSING? WATER SOLID RESIDUE MINERALS NUTRIENTS FATS AND OILS LEFTOVERS MACRO COMPONENTS IN FOOD WASTE Carbohydrates are by far the major component of biodegradable wastes and include cellulose, starch and sugars. Proteins are large complex organic materials composed of hundreds or thousands of amino acids groups. Lipids or fats are materials containing fatty acids. Commodity – types of product Raw product quality FACTORS OF Harvest and transport – manual vs automize WASTE GENERATION Equipment and processing capacity Water use Awareness Fruit and vegetable Highly biodegradable Fruit & vegetable processing – fruit products, fruit juice Waste – fiber, pigments, seeds, nutrients These processes causes pollution Fruit and vegetable Meat and poultry products Contribute to major waste Waste present in almost every process from water waste to solid waste Processing also causes high energy input other than pollution (BOD, COD) Canned food Cooking Fats, oils and greases (FOG) By products of meat Blood Visceral Bones Meat and Poultry Products Alternative Use: 1. Protein Recovery and Feed - Blood; source of protein 2. Energy recovery - Meat and bone 3. Heavy metal adsorption - Meat waste, biological origin absorbs metal better Dairy Products Main waste – dairy wastewater which contains 1) Fats and oils 2) Protein 3) Salt 4) lactose 5) chemicals Dairy wastewater contains high BOD and COD Plastic packaging Wastewater Fermentation Aeration Fish and Seafood Products Different type of waste with different type of processing Waste from seafood: Skin Bone Fat Washing water Head, shell Acid/alkali waste from protein extraction, encapsulation Food Packaging Waste FOOD PACKAGING WASTE HOW MANY TYPE OF PACKAGING MATERIAL? WAYS OF DISPOSING PACKAGING MATERIAL? IMPACT OF PACKAGING MATERIAL AND ITS DISPOSING PROCESS? Glass Started 5000 years ago and the Egyptian created the methods of hand blowing 1000 years later Created using sand, soda and limestone (1200 – 1500 degrees Celsius) Inactive and bio-degradable Comes in different color. Common: Green - sparkling Brown – protection from light – juice, alcohol Clear – mineral, drinking Breaks down to silicon and sand – elements of the earth Could be use in the WTE industry as RDF Waste management Glass recycling Glass Recycling Process 1. initial rinsing, cap and lid removal – metal detector 2. colour separation – new technology uses lamps and laser 3. volume reduction by breaking or crushing 4. packaging and shipping 5. final treatment. Aluminum Basic element – in periodic table (AL13) Used due to non-magnetic, cheap, durability, low density, resist corrosion and stable Famous packaging material and used worldwide Light, barrier and insulation, hygienic, easy to open, good conduction Can be converted to metal with unique magnetic properties after recycling Waste management Aluminum recycling Aluminum Recycling Two methods Conventional Direct Convention The difference is the end product and amount of recycle Direct convention saves money, energy and man power Uses fossil fuel and salt – produces ‘salt cake’ which is hazardous 16-19GJ/t needed 5-6GJ Paper/carton 1950 – 50 million tons were produced 1998 – 300 million tons 2010 – 400 million tons Problems – Ink, Adhesive Responsible for large discharge of highly polluted effluents High toxicity Low biodegradability Tannin, lignin, resins, chlorophenolic compound Paper/carton recycling Polymer Type of polymer Natural synthetic polymer – PET bottle Partially degradable polymer – starch plastic bags Biodegradable polymer – technology development Waste management Landfill Composting Incineration Re- use Recycling Polymer Recycling Recycled materials are not allowed to be use again in food industry as it contains chemical contaminant Some recycled material causes health complication when it is expose to food and digest Some polymer are dispose through composting and incineration after single use because it could not be recycled Polymer Recycling No.1 – repeated use will cause leeching and bacterial growth Should be recycle not reuse No.2 – Reusable and recyclable No.3 – Impervious to sunlight and weather ‘poison plastic’ Not recycle or reuse No.4 – Reusable but not always recyclable No.5 – Reusable and recyclable No.6 – Leach styrene – carcinogenic Min recycling but reusable with caution Avoid using preferable No.7 – Not recycle or reuse WASTE MANAGEMENT Biological Waste Treatment Anaerobic Digestion Aerobic Digestion Biodiesel Production Composting Coagulation/electrocoagulation/ precipitation/flocculation Bioremediation Animal Feed Landfill Anaerobic Digestion Anaerobic digestion is a series of biological processes in which microorganisms break down biodegradable material in the absence of oxygen Bouallagui et al. (2005) reviewed the potential of anaerobic digestion for material recovery and energy production from fruit and vegetable wastes (FVW) containing 8–18% total solids (TS), with a total volatile solids (VS) content of 86–92%. The organic fraction includes about 75% easy biodegradable matter (sugars and hemicellulose), 9% cellulose and 5% lignin. Two types: 1) Mesophilic Digestion 2) Thermophilic Digestion Anaerobic Digestion Anaerobic digestion consists of three steps. 1st step is the decomposition (hydrolysis) - the organic material breaks down to usable-sized molecules such as sugar. In this step, organic waste is placed into a digester and mixed with air influx water and steam to break down the waste 2nd step is the conversion of decomposed matter to organic acids. The organic waste converted into liquid flows into a second digestor and naturally occurring microbes decompose fatty acids to produce acetate and other simple alcohols 3rd step is acids are turned into methane gas. The methane gas flows towards a double membrane storage tank where it is temporarily stored. Biogas is conveyed to gas engines where it is converted into electricity. Some solid organic waste passes through the digestion process without being broken down into a liquid. This solid organic waste is screened to remove sand, glass and plastics and is then composted to produce Advantage Ability to generate electricity and heat (through the combustion of the biogas) Odor control Reduction of pathogens Ability to use digested (separated) solids as bedding Ability to spread digested (separated) liquid effluent at different times and different places than was previously Socially acceptable No dioxins or other toxic by-products DISADVANTAGE High capital and operating costs Slower waste disposal than incinerators Ineffective treatment of plastics and other synthetic wastes Difficult to manage with heterogeneous wastes Aerobic Digestion Aerobic digestion is a biological process that takes place in the presence of oxygen. With oxygen, bacteria present in the sludge (activated sludge) consumes organic matter and converts it into carbon dioxide Frequently used to remove the pollution generated by wastewaters Aerobic processes have high operating costs and generate large quantities of waste sludge which require further disposal Useful by-product such as methane is not recovered Often combined with anaerobic digestion aerobic Digestion Covered lagoon digesters are the simplest anaerobic digester system. These systems consist of an anaerobic combined storage and treatment lagoon, an anaerobic lagoon cover, an evaporation pond for the digester effluent and a gas treatment and/or energy conversion system. A collection pipe starting from the digester carries the biogas to either a gas treatment system such as a combustion flare, or to an engine/generator or boiler that uses the biogas to produce electricity and heat. Following treatment, the digester effluent is often transferred to an evaporation pond or to a storage lagoon prior to land application. Covered lagoon digesters are most appropriate for use in warm climates if the biogas is to be employed for energy or heating purposes aerobic Digestion Complete mix digesters is a large, vertical poured concrete or steel circular container. Nowadays, complete mix digester can treat organic wastes with total solid concentration of 3 to 10%. Complete mix digesters can be operated at either the mesophilic or thermophilic temperature Plug flow digesters are normally used where wastes are collected as solids (solids greater than 11%). Plug flow digesters are large tanks (often built into the ground) with an impermeable plastic cover. Although the contents are usually heated, they are not mixed because they move through the digester as a combined mass or a ‘plug’. Plug flow digesters have been used mostly with scraped dairy wastes, but a few were also applied to swine wastes aerobic Digestion Complete Mix Digester Plug flow digester volatile solids reduction is approximately equal to that obtained anaerobically lower BOD concentrations in supernatant liquor production of an odorless, humus-like, biologically stable end product recovery of more of the basic fertilizer values in the sludge operation is relatively easy lower capital cost Disadvantage a high power cost is associated with supplying the required oxygen a digested sludge is produced with poor mechanical dewatering characteristics The process is affected significantly by Temperature Location Type of tank material Comparison aerobic and anaerobic Composting Increase the concentration of soil organic matter, improve tilth and water holding capacity, suppress weeds and provide a long-term supply of nutrients as the organic material decomposes (Ozores-Hampton and Obreza, 1999; Evanylo and Daniels, 1999) An important source of organic material for composting or soil restoration that is largely untapped is solid waste from the pulp and paper industry. Composting Organic matter is converted by composting into a stable substance which can be handled, stored, transported and applied to the field without having adverse effects to the environment. Proper composting effectively destroys pathogens and weed seeds through the metabolic heat generated by the microorganisms. Such composts are not suitable as fertilizers or soil conditioners but can suppress soil-borne plant pathogens. Composting Third level Large insect or worms Chewing, tearing, sucking - physical Ants, millipede, slugs, snails etc Second level Smaller insects Eat organic matters Mites, springtails, nematodes, protozoa First level Microorganisms Chemical degrade organic as nutrient and substance Bacteria, fungi, actinomycetes Bacteria 1,000,000 – 1 billion present per gram of compost. Actinomycetes 100,000 -100 million in a gram of compost. Fungi 10,000 -1,000,000, fungal cells per gram of compost. COAGULATION/ELECTROCOAGULATION/PRECIPITATION/FLOCCULATION Coagulation or destabilization of a colloidal suspension results in joining of minute particles by physical and chemical processes. Flocculation results in formation of a larger settleable structure by bridging. Commonly used to remove suspended matter or color. Adsorption of ionic forms also occurs depending on the constituents in the water or wastewater Chemical precipitants, coagulants and flocculator are all used to increase particle size through aggregation The most widely used chemical precipitation process is hydroxide precipitation. Calcium hydroxide (lime) or Sodium hydroxide (caustic) Advantage Completely enclosed Well-established Some treatment systems are often technology with chemicals (i.e. lime) conveniently self- readily available are very inexpensive operating with low equipment maintenance Increase in Effective in removing Removal of very fine agronomic value of protozoa, bacteria particles the sludge and viruses Disadvantage Calculation of proper chemical dosages is impossible (due to the competing reactions) Jar tests are necessary for confirmation of optimal treatment conditions Overdosing greatly decreases the effectiveness Required working with corrosive chemicals (precipitation) increases operator safety concerns Chemicals addition (i.e. lime) increases waste of the sludge volume up to 50% Transportation of large amounts of chemicals to the treatment location Polymers can be expensive Bioremediation Bioremediation is a treatment process employing naturally occurring microorganisms (yeast, fungi, or bacteria) to break down, or degrade, hazardous substances into less toxic or non-toxic substances Bioremediation is not a panacea but rather a ‘natural process’ alternative to methods like incineration, catalytic destruction, use of adsorbents and physical removal and subsequent destruction of pollutants Bioremediation occurs either under aerobic or anaerobic conditions. Under aerobic conditions, microorganisms can only survive through consumption of atmospheric oxygen. Under anaerobic conditions, since no oxygen is present, the micro-organisms break down chemical compounds in the soil to release the energy they need Advantage Natural and safe process Cost effective Final solution Non-disruptive and non- invasive Performed in-situ Disadvantage Ineffective for non-degradable systems Biodegradation products occasionally more toxic than the parent compounds Lengthier than other treatment methods Constant monitoring to ensure effectiveness Not applicable to complex mixtures of contaminants Biodiesel production Bio-Diesel - Alternative fuel, biodegradable and non-toxic Fruit and vegetable waste (FVW) are good biodiesel source Example: palm oil waste in Malaysia Fruits and vegetable solid wastes (FVSW) represent a potential energy resource if they can be properly and biologically converted to methane. They are renewable and their net CO2 contribution to the atmosphere is zero. LANDFILLING Landfilling consists of five stages: 1 hydrolysis/aerobic degradation 2 hydrolysis and fermentation 3 acetogenesis 4 methanogenesis 5 oxidation.