Mercury disposal

One area that requires additional study is the use of elemental mercury by members of specific religious or ethnic groups in their ceremonies, rituals, and practices so an assessment of the magnitude of these activities can be made. In addition, information on how mercury is used in these ceremonies and rituals, as well as the methods of mercury disposal used, would be helpful in assessing the potential pathways for human exposure and environmental releases. 

Dispose of the mercury collection bottle, and other equipment used in contact with the spill, by approved mercury disposal— i.e., contain equipment in secure, labeled bag and place in the solid mercury waste disposal drum (Hazardous Waste Storage Area). Dispose of in the solid mercury waste drum. 

In addition to the health impacts due to the absorption and accumulation of mercury in various organs, the environmental damage caused by mercury disposal is worrisome. A study performed in 2005 by the World Health Organization pointed out that 53% of total mercury emissions come from the disposal of amalgam flushed down the drain and laboratory devices in dental offices. 

Coalition ofJSlortheast Governors. The CONEG model heavy-metal guideline is implemented through state regulations and limits total metal content of lead, chromium, mercury, and cadmium. The limitation of 100 parts per million total is aimed at protecting the environment from the disposal of post-consumer waste. 

Regulations. In order to decrease the amount of anthropogenic release of mercury in the United States, the EPA has limited both use and disposal of mercury. In 1992, the EPA banned land disposal of high mercury content wastes generated from the electrolytic production of chlorine—caustic soda (14), accompanied by a one-year variance owing to a lack of available waste treatment faciUties in the United States. A thermal treatment process meeting EPA standards for these wastes was developed by 1993. The use of mercury and mercury compounds as biocides in agricultural products and paints has also been banned by the EPA. 

The State of New Jersey has passed a law restricting the sale and disposal of batteries (qv) containing mercury, requiring manufacturers to reduce the mercury content of each battery to 1 ppm by weight by 1995, and to estabhsh a collection program for spent batteries (14). Another New Jersey law bans the sale of products having cadmium, mercury, or other toxic materials in the packaging (14) (see Cadmiumand cadmium alloys Cadmium compounds Mercury compounds). 

California and Minnesota have placed restrictions on the disposal of fluorescent light tubes, which contain from 40—50 mg of mercury per tube, depending on size. After batteries, fluorescent lamps are the second largest contributor of mercury in soHd waste streams in the United States (3,14). A California law classifies the disposal of 25 or more fluorescent lamp tubes as hazardous waste. In Minnesota, all waste lamps generated from commercial sources are considered hazardous waste. Private homes are, however, exempt from the law (14). Other states have proposed similar regulations. Several companies have developed technologies for recovering mercury from spent lamps (14). 

A goal of reducing total mercury releases in the United States by 33% between 1988 to 1992, and 50% by 1995 was set by the EPA. The 1992 goal was more than achieved United States reportable mercury releases were reduced by 39% by 1991 (26). In the United States, discards of mercury in municipal soHd waste streams were approximately 643 t in 1989 (3). As a result of increased restrictions on the use and disposal of mercury, by the year 2000 mercury in municipal soHd waste streams is expected to be about 160 t (3). 

Mercury from these accumulated wastes is generally best recovered by total degradation in stills, where metallic mercury is condensed and collected. The recovery costs are amply compensated by the value of the metal recovered. Moreover, disposal problems are either eliminated or severely diminished. 

Environmental Factors. The control, recovery, and disposal of mercury-bearing waste products are as important to the mercurials industry as the manufacturing process. The difficulties involved in removing mercury from waste-product streams and the problems of recovery or disposal have resulted in a substantial reduction in the number of manufacturers of mercury compounds as well as in the variety of mercury compounds being manufactured. Moreover, the manufacturing process used for a mercury compound may not necessarily be the most efficient or economical. Rather, the choice may depend on the nature of the by-products, the toxic hazard of the process, and the ease of recovery of the mercury from the waste-product stream. 

Suitable ventilating equipment, consisting mainly of carbon absorbers which effectively absorb mercury vapor from recirculated air, must be employed to maintain standards below the value permitted in the occupational environment. When the possibiUty of higher exposures exists, small disposable masks utilizing a mercury vapor absorbent may be employed. 

HEAVY METALS A gi oup of metals which are sometimes toxic and can be dangerous in high concentrations. The main heavy metals covered by legislation are cadmium, lead, and mercury. Industrial activities such as smelting, rubbish burning, waste disposal and adding lead to petrol increase the amount of toxic heavy metals in the environment. 

Because of quite poor color rendition and difficulty in safe disposal of expended lamps, low pressure sodium fixtures are less desirable than high pressure sodium fixtures and are seldom recommended for production facilities. High pressure sodium fixtures are particularly attractive for illuminating large open areas. At locations where power cost is low and where many fixtures are required due to equipment shadowing, mercury vapor fixtures often are preferred because of their lower initial cost, lower replacement lamp cost, and better color rendition. 

Some battery-producing companies prefer purchasing pure, nonamalgamated zinc powder to apply their own proprietary corrosion protection system. The general trend is to keep the anodes of all the consumer cells mercury-free (usually indicated by a "green label) and to make them disposable with the regular household trash. The exceptions to this rule are those cells where this makes no sense, such as cells with a mercuric oxide cathode. 

A number of environmental issues have received widespread publicity (Table 7.1), from major accidents at plants (e.g., Seveso and Bhopal) to the global and regional impacts associated with energy utilization (e.g., carbon dioxide, acid rain, and photochemical oxidants), the improper disposal of chemical waste (e.g., Love Canal and Times Beach), and chemicals that have dispersed and bioaccumulated affecting wildlife (e.g., PCBs and DDT) and human health (e.g., cadmium, mercury, and asbestos). 

As mentioned above, approximately 7% of the total sulfur present in lead ore is emitted as S02. The remainder is captured by the blast furnace slag. The blast furnace slag is composed primarily of iron and silicon oxides, as well as aluminum and calcium oxides. Other metals may also be present in smaller amounts, including antimony, arsenic, beryllium, cadmium, chromium, cobalt, copper, lead, manganese, mercury, molybdenum, silver, and zinc. This blast furnace slag is either recycled back into the process or disposed of in piles on site. About 50 to 60% of the recovery furnace output is slag and residual lead, which are both returned to the blast furnace. The remainder of this dross furnace output is sold to copper smelters for recovery of the copper and other precious metals. 

The objectives sought to be achieved through disposal of refrigeration and air conditioning waste appliances are (a) separate disposal of the CFCs from the circulation system and the insulating material (b) further stripping of hazardous substances (e.g., mercury switches) and (c) recovery of ferrous metals, the priority in metal recycling. 

The requirements for proper disposal of refrigeration and air conditioning waste appliances are very stringent (a) mercury switches and condensers containing PCBs must be removed in advance... 

Stripping of hazardous substances Mercury switches and other components containing particularly hazardous substances must be removed CFCs are recovered from the cooling circuit and PU foam with special equipment and appliances with varying degrees of automation ammonia is dissolved in water and separate disposal of waste oil (from compressors). 

Management and Disposal of Mercury-Containing Equipment Including Lamps... 

Because many batteries contain toxic constituents such as mercury and cadmium, they pose a potential threat to human health and the environment when improperly disposed. Although batteries generally make up only a tiny portion of MSW, <1%, they account for a disproportionate amount of the toxic heavy metals in MSW. For example, the U.S. EPA has reported that, as of 1995, nickel-cadmium batteries accounted for 75% of the cadmium found in MSW. When MSW is incinerated or disposed of in landfills, under certain improper management scenarios, these toxics can be released into the environment. 

Environmental hazards of batteries can be briefly summarized as follows. A battery is an electrochemical device with the ability to convert chemical energy to electrical energy to provide power to electronic devices. Batteries may contain lead, cadmium, mercury, copper, zinc, lead, manganese, nickel, and lithium, which can be hazardous when incorrectly disposed. Batteries may produce the following potential problems or hazards (a) they pollute the lakes and streams as the metals... 

Heavy metals have the potential to enter the water supply from the leachate or runoff from landfills. It is estimated that nonrecycled lead-acid batteries produce about 65% of the lead in the municipal waste stream. When burned, some heavy metals such as mercury may vaporize and escape into the air, and cadmium and lead may end up in the ash, making the ash a hazardous material for disposal. 

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