Hazardous and Toxic Waste,Environmental concerns and heath problems of hazardous waste; toxicity and its measurement,Learning outcomes,When you have studied the information in this lecture you should be able to: Define solid waste and compare solid waste disposal methods Identify the sources of toxic waste Identify major environmental toxins Explain effect of toxic pollutants Explain how waste is classified,Topics,Solid Waste Toxicity Classification and Characteristics of waste Pharmaceutical Wastes Hazardous waste management,Types of Solid Wastes,Municipal Solid Waste (MSW)- what “we” produce daily Hazardous Waste A subset of solid waste Industrial Waste Agricultural Waste Mining Waste,Medical Waste Air Pollution Control Residuals WWTP residuals Organic and bacteria residue from waste WTP residuals Mainly metallic salt,How Do You Manage Solid Waste?,Prevent Minimize Recycle Compost Waste to Energy Landfill,Waste Prevention and Source Reduction,Re-engineering of a product or process Use less packaging Re-use Do not let the material enter the waste stream in the first place Consume less materials Example: Double-sided printing,Recycling,Taking a discarded product and using to make a new product Same as first one An entirely new product Examples?,Recycled municipal solid waste components,Fibers Newspaper Cardboard Office Paper Containers Glass Plastic Metal,Major Markets: New paper products, other products (e.g. insulation),Recycled municipal solid waste components,Fibers Newspaper Cardboard Office Paper Containers Glass Plastic Metal,Commonly recycled plastics再生塑料,PET (polyethylene terephthalate) Original use: Beverage bottles Recycled use: Carpet fibres, insulation HDPE Original use: milk, juice bottles Recycled use: oil and soap bottles, drain pipes,PVC Original use: food wraps, bottles Recycled use: floor tiles, traffic cones LDPE Original use: bin bags, wraps Recyled use: irrigation pipes, oil bottles,Composting 堆肥,A form of biological treatment Aerobic 有氧 Diverse Fungi, bacteria, insects, worms Anaerobic 厭氧 Fairly well defined groups of bacteria Commonly applied to bio-solids, garden waste and agricultural waste Less commonly applied to MSW,What types of solid waste are produced as a result of pharmaceutical production?,Toxicity,Measure the degree to which something is toxic or poisonous Depends on dose, duration and route of exposure Exposure routes Dermal Inhalation Ingestion,Toxins,Term toxin usually used when talking about toxic substances produced naturally A toxin is a poisonous substance of microbial, vegetable or synthetic origin that reacts to kill cells, alter growth or kill the organism,Plant Toxins did you know?,Stones and pips of apricots, plums, cherries, peaches, apples and pears all contain glycosides which if eaten release potentially lethal doses of cyanide Rhubarb contain large quantities of oxalic acid, which interferes with calcium absorption,Plant Toxins did you know?,Many plants of the Brassicia (cabbage) family contain goitrogens goitrogens interfere with the production of thyroid hormones by preventing iodine incorporation Potatoes which have turned green, sprouted or have developed a bitter taste are toxic because they contain solanine. Defence mechanism for the plant (e.g. anti-fungal properties) Honey from rhododendrons is highly toxic,Toxins in Nature did you know?,The liver of the blow fish (puffer fish) is extremely poisonous There is cyanide in cassava and almonds (there are official limits for cyanide concentration in marzipan).,Belladonna, strychnine and aconite: three of the most poisonous plants in the world. One of these deadly alkaloid toxins was used to murder Alexander the Great.,Cherry lauryl: leaves can cause cyanide poisoning. Often found in hedges and in parks.,Amanita phalloides, the death cap mushroom, is a cause of acute liver failure,Types of toxic entities,Chemical Example; Heavy metals, pesticides Biological threshold value can be a single organism Plant toxins- yew tree Animal toxins snake bites Physical Heat and cold, IR and UV radiation, X rays and gamma rays, alpha and beta rays,Environmental Toxins,Some are designed to be toxic (e.g., pesticides, herbicides), while others are used for industrial purposes. Most toxins can be categorized into the following groups. Dioxins and Furans PCBs (Polychlorinated biphenyls) HCB (hexachlorobenzene) Pesticides Heavy Metals,Dioxins and Furans,Dioxins and Furans are chlorinated chemicals that originate from various sources, including waste incinerators, waste water from paper industry and by-products from general industry. The term Dioxins include 75 polychlorinated dibenzo-p-dioxin (PCDD) and 135 polychlorinated dibenzo furan (PCDF) substances. Of these, 17 are toxic in very small amounts.,PCBs (Polychlorinated biphenyls),PCBs were used for many years in transformers, capacitors and certain building materials. Although PCBs are not produced today, they are still found in the environment from the disposal