Mercury Vapor Release from Broken Compact Fluorescent Lamps and In Situ Capture by New Nanomaterial Sorbents

Abstract

The projected increase in the use of compact fluorescent lamps (CFLs) motivates the development of methods to manage consumer exposure to mercury and its environmental release at the end of lamp life. This work characterizes the time-resolved release of mercury vapor from broken CFLs and from underlying substrates after removal of glass fragments to simulate cleanup. In new lamps, mercury vapor is released gradually in amounts that reach 1.3 mg or 30% of the total lamp inventory after four days. Similar time profiles but smaller amounts are released from spent lamps or from underlying substrates. Nanoscale formulations of S, Se, Cu, Ni, Zn, Ag, and WS2 are evaluated for capture of Hg vapor under these conditions and compared to conventional microscale formulations. Adsorption capacities range over 7 orders of magnitude, from 0.005 (Zn micropowder) to 188 000 μg/g (unstabilized nano-Se), depending on sorbent chemistry and particle size. Nanosynthesis offers clear advantages for most sorbent chemistries. Unstabilized nano-selenium in two forms (dry powder and impregnated cloth) was successfully used in a proof-of-principle test for the in situ, real-time suppression of Hg vapor escape following CFL fracture.

Use of biogenic and abiotic elemental selenium nanospheres to sequester elemental mercury released from mercury contaminated museum specimens

“…Size distribution information was obtained (Fig. 8E) and was concordant with SEM analyses show particles ranging from 40 to 700 nm, similar to that as reported by Johnson et al [13]. Size distribution information was used to calculate surface area assuming spherical particles; abiotic Se 0 had a surface area of 11.64 m 2 g −1 and biogenic Se 0 9.64 m 2 g −1 equating to 5.8-7.0 × 10 −3 m 2 and 4.8-5.8 × 10 −3 m 2 per filter, respectively.…”

“…Cultures were incubated at 30 • C and red Se 0 was precipitated. To produce abiotic Se 0 , a solution containing 1 mmol l −1 Na 2 SeO 3 and 4 mmol l −1 glutathione (reduced) was titrated against a 1N NaOH solution until the formation of red elemental Se was observed [13]. For the sequestration experiments, biogenic and abiotic red Se 0 suspensions (5 ml) were filtered through 0.22 m polycarbonate micropore filters, washed with deionised H 2 O (5 ml) and allowed to air dry.…”

“…Johnson et al [13] studied the capture of Hg 0 v by nanoscale sorbents, and note that elemental ␣-Se nanoparticles sequester Hg more efficiently than many commercially available sorbents. Se nanoparticles can be produced biogenically by bacterial reduction of soluble Se oxyanions.…”

Adsorption of zinc by biogenic elemental selenium nanoparticles

“…Indeed, chemically produced selenium nanoparticles (CheSeNP) adsorb high quantities of copper (800 mg of Cu adsorbed per g of elemental selenium nanoparticles) [10]. Both CheSeNPs and BioSeNPs adsorb mercury from mercury vapor by forming mercury selenide precipitates [11,12,13]. However, chemical elemental selenium nanoparticles production methods entail high production costs and are not environmental benign due to the use of toxic solvents, high temperature and high pressure [14,15,16].…”

Environmental Pollution by Mercury and Related Health Concerns: Renotice of a Silent Threat

“…Compact fl uorescence lamps (CFLs) are among the most widely used mercury-containing products for which different regulations have been set in the US and Europe. Starting with 2007, the US National Electrical Manufacturers Association (NEMA) set a reduction limit for mercury in CFLs, whereas an identical limit had previously been set by the Restriction of Hazardous Substances Directive (RoHS) in the EU (15). In some parts of the world such as the US, Canada, Australia, and Europe, CFLs are defi ned as products subject to recycling schemes; for instance, through the Waste Electrical and Electronic Equipment Directive (WEEE) in the EU.…”