Materials engineering

quicksilver is a common element that is found naturally in a large-minded state or mixed in ores. Because atomic number 80 is very dense, expands and contracts evenly with temperature changes, and has high electrical conductivity, it has been use in thousands of industrial, agricultural, medical, and family applications. Major uses of mercury include dental amalgams, tend switches, thermometers, lamps, pigments, batteries, reagents, barometers, manometers, and hydrometers. It also may be present in rocks or released during volcanic activity. (Ross & Associates, 1994)Mercury can enter the environment from a keep down of passages. For example, if a mercury- insureing item is thrown into the garbage, the mercury may be released into the gentle wind from landfill vapors or, or the mercury may vaporize if the trash is incinerated. If mercury is flushed through a bollixwater system, the mercury go out likely adhere to the wastewater sludge, where it has the potential to volatili ze and be depo pointd elsewhere. Mercury can enter the atmosphere through these various means because it evaporates substantially. It can travel through the atmosphere in a volatilised state. (Ross & Associates, 1994)Once mercury is deposited into lakes and streams, bacteria convert some of the mercury into an organic form called methylmercury. This is the form of mercury that humans and other animals ingest when they eat some types weight. Methylmercury is particularly dangerous because it bioaccumulates in the environment. Bioaccumulation occurs when the methylmercury in fish tissue concentrates as larger fish eat smaller fish. (U.S. EPA, 1994)Methylmercury interferes with the nervous system of human frame and can result in a decreased ability to walk, talk, see, and hear. In extreme examples, high levels of methylmercury white plague look at resulted in coma or death. M either animals that eat fish also accumulate methylmercury. Mercury can interfere with an animals ability to reproduce, and lead to weight loss, or early death. (Ross & Associates, 1994)Instruments containing mercury on campusThermometers verbal description Thermometers include fever thermometers for home and medical use, laboratory thermometers, and industrial thermometers.How to depict The bulbs of thermometers containing mercury are ordinarily silver in color. Types of mercury thermometers on campus include Laboratory and weather thermometers.Amount of Mercury representative fever thermometers contain about 0.5 grams of mercury each, while laboratory thermometers contain up to 3 grams of mercury. befoulment Prevention Options Mercury-free alternatives are digital, aneroid, and alcohol thermometers, and for most applications they are as accurate as mercury thermometers. digital thermometers tend to last longer, however, because they are less likely to break.Safe Handling Mercury thermometers are substantially broken when not handled carefully. If the break occurs, use two pieces of paper or two razor blades to pouch it up from a smooth surface. An eyedropper or a mercury vacuum can also be used. Mercury spill kits are available from safety equipment supply companies for large mercury spills. (U.S. EPA, 1994)Safe presidential term Save old or broken thermometers in an air-tight container. Homeowners can use local household hazardous waste collection schedules for disposal. Businesses should deliver their thermometers to a consolidation site or arrange for a transporter to take them. Contact your county or state environmental situation or solid waste office for services available in your area. Also, save the invoices that track your waste that include the following culture date of shipment, amount of waste, location from where waste is shipped, and destination of shipment. contains translation Mercury-containing moderates use mercury tilt switches.How to Identify nigh thermostats, other than electric thermostats, contain mercury. To determine if a ther mostat contains mercury, remove the front plate. Mercury-containing thermostats contain one or more small mercury switches. Thermostats are generally mounted on walls and easily found. (U.S. EPA, 1994)Amount of Mercury About 3 grams of mercury are in each mercury tilt switch. Most thermostats have one switch some have two, and up to six switches are possible. taint Prevention Options Programmable electronic thermostats are mercury free, and they are more energy-efficient than the mercury model. Look for programmable electronic thermostats that have the Energy Star label.Safe Removal Remove the entire thermostat using a screwdriver and a pair of wire-cutters and store safely. Dont remove the switches from the thermostat, or dismantle the thermostat.Safe Disposal Store the entire thermostat in a marked container until it can be sent for proper disposal. In many states, the Thermostat recycle Corporation operates a cycle program utilizing heating, ventilation and air conditioning (HVA C) wholesalers eventually this program will be in operation nation-wide. The wholesalers consolidate thermostats from contractors and send them to recyclers only whole thermostats are accepted. (U.S. EPA, 1995)SwitchesDescription Mercury is contained in temperature-sensitive switches and mechanical tilt switches. Mercury tilt switches are small tubes with electrical contacts at one end of the tube. As the tube tilts, the mercury collects at the lower end, providing a conductive path to compete the circuit. When the switch is tilted back, the circuit is broken.How to Identify A mercury tilt switch is unremarkably present when no switch is visible. They are used in thermostats, silent light switches, and clothes washing machine lids.Amount of Mercury About 3.5 grams of mercury are contained in a small electrical switch. industrial switches may contain up to 8 pounds of mercury.defilement Prevention Option Alternatives to mercury switches include hard-contact switches and substantia lness switches.Safe Removal Remove switches from appliances very carefully so as not to release any mercury into the environment.Safe DisposalStore mercury switches in a suitable leak proof, closeable containers. A five gallon charge plate bucket with a lid may work.Each container must be labeled Mercury Switches for Recycling.Be careful to keep the switches from breaking and releasing mercury into the environment.If breakage occurs, you must immediately take steps to contain and clean up the spill.Take switches to a consolidation site or arrange with a transporter to take them.Contact your county or state environmental office/ solid waste office for services in your area.Keep records of the mercury switches you have recycled, including copies of invoices containing information on the date of shipment, number of switches, and location. (U.S. EPA, 1994)Manometers, Barometers, and HydrometersDescription Manometers and barometers are used for measuring air pressure. Hydrometers are u sed to evaluate density of liquid.How to Identify All these devices will have a gauge for reading air pressure.Pollution Prevention Options The Replacements of mercury containing Manometers are battery operated digital units and vacuum gauges. Battery operated digital units are highly sensitive.Safe Removal To safely remove the manometer or barometer, remove the entire device from the machine it is link to.Safe Disposal Put the entire unit into an airtight, labeled container and ship it to a mercury recycling plant.SphygmomanometersDescription Sphygmomanometers are used to measure blood pressure.How to Identify Usually, they are installed on walls and placed on tables in hospitals.Pollution Prevention Options The replacement for mercury sphygmomanometers includes electric vacuum gauges, aneroid monitors, and automated devices.Recycling/Disposal Develop a protocol for the preparation of mercury sphygmomanometers for recycling or disposal that that is consistent with U.S. Environme ntal Protection Agency, state and local regulations, and pertinent standards. Contact your hazardous waste management coordinator for flesh out about packaging, labeling and transporting that are specific to your facility. A suggested protocol might include the following instructions key the sphygmomanometer in a clear plastic bag and seal the bag. Do not use a red bag biohazard bag. Mark the bag Contains Mercury. Place the bag in a plastic basin to contain any spills during transport to the designated hazardous waste collection point. BatteriesDescription Mercury zinc, carbon paper zinc, silver oxide, and zinc air contain mercury. Mercury is used to protect cathode from oxidation.Pollution Prevention Options Most consumers dry-cell batteries contain no added mercury. The best way to reduce mercury is recycling. (U.S. EPA, 1994)ReferencesRoss & Associates Environmental Consulting, Ltd. (1994), Mercury Sources andRegulations Background learning for the practical(prenominal) Elimi nation Pilot Project.Ross & Associates Environmental Consulting, Ltd. (1994), Polychlorinated BiphenylsSources and Regulations Background Information for the Virtual EliminationPilot Project.U.S. EPA. (1994), Virtual Elimination Pilot Project Briefing Packet for MeetingParticipants,U.S. EPA. (1995), Mercury Study Report to intercourse (External Review Draft)(External Review Draft) U.S. EPA. (1995), Mercury Study Report to Congress