Download VII.Heavy metals non essensial

Logam dalam sistem
kimiawi perairan laut
(non essensial)
Arsenic
Lead
Mercury
Logam berat di perairan
laut
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Essensial: Cr, Ni, Cu, Zn
Non essensial: As, Cd, Pb, Hg
Logam terlarut :
Raksa (Hg)
mg/l
Baku mutu
KepMenLH 51 2004
0,001
Kromium heksavalen
( Cr (IV) )
Arsen (As)
mg/l
0,005
mg/l
0,012
Kadmium (Cd)
mg/l
0,001
Tembaga (Cu)
mg/l
0,008
Timbal (Pb)
mg/l
0,008
Seng (Zn)
mg/l
0,05
Nikel (Ni)
mg/l
0,05
Hg
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Karakteristik
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It called hydragyrum, a silver-white
Heavy liquid at ambient temperature
(250C)
It has atomic mass 200,6 g/mol and atomic
number 80
It has boiling point of 356.70C, melting
point of -38.870C
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Konsentrasi dan spesies Hg
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Hg mempunyai banyak spesies di alam
antara lain elemen metal Hg, monovalen,
ion divalen, dan campuran metalik organik
Kandungan alami Hg di kerak bumi 0,8
mg/kg, sementara di air laut 0,015 mg/L
Di lingkungan laut, 90 % senyawa Hg
diubah menjadi alkil Hg
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The fate and transport of Hg
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The global Hg cycle comes from
Atmosphere, Ocean and Surface soil
Hg transportation from one reservoir to
another mainly occurs through the
atmosphere
The atmospheric half-life of elemental Hg is
∼0.5 to 1 year, which is what allows it to
be distributed globally
Toxicity – Dependent on form
Elemental - Hg0 : Vapour, highly toxic
Inorganic – Hg+, Hg2+:
Not easily absorbed, but risk of kidney damage if ingested
Organic – R-Hg, e.g. methyl mercury:
More toxic than inorganic, risk of brain & CNS damage.
Can cross blood-brain barrier and placenta
Attraction for sulphur groups, thus can inactivate enzymes
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When deposited in soil,
organic mercury compounds
are slowly broken down into
inorganic compounds;
inorganic mercury can be
converted by
microorganisms in soil and
water into the organic
compound methyl mercury,
which is then
bioconcentrated up the food
chain.
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Source
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Anthropogenic activity altered the global Hg
anthropogenic Hg sources are coal burning, waste
incineration and mining.
Industries activity such as some chemical, chlor-alkali,
chlorine, metal-processing, electrical-equipment,
automotive, and building industries and in medical and
dental services.
The main sources of Hg in municipal waste are
batteries, thermostats, paint residues, fluorescent
lamps
HEALTH IMPACTS
Daily sources
Health impacts
Pb
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Karakteristik
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Pb dikenal dengan nama plumbum
Nomor atom (82), dan berat atom 207,2
Berwarna kecoklatan dan lunak
Tahan terhadap korosi dan karat
Titik lebur nya rendah (372,50C)
Bukan konduktor yang baik
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Konsentrasi dan spesies Pb
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Lead can occur in three oxidation state Pb, Pb(II) and Pb(IV)
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ionic form (highly mobile and bio-available),
 organic complexes with dissolved humus materials
(binding is rather strong and limits availability),
 attached to colloidal particles such as iron oxide (strongly
bound and less mobile when available in this form than
as free ions) or
 Atteched to solid particles of clay or dead remains of
organisms (very limited mobility and availability).
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Lead in the atmosphere will deposit on
surfaces or exist as a component of
atmospheric particles.
In soil, lead is generally not very mobile.
Lead speciation in seawater is a function of
chloride concentration and the primary
species are PbCl3 > PbCO3> PbCl2> PbCl+>
and Pb(OH)+
BIOACCUMULATION
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Sources
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Natural sources - releases due to mobilisation of naturallyoccurring lead in the Earth's crust and mantle, such as
volcanic activity and weathering of rocks;
Current anthropogenic (associated with human activity)
releases from the mobilisation of lead impurities in raw
materials such as fossil fuels – particularly ores, coal and
other extracted, treated and recycled minerals;
Current anthropogenic releases resulting from lead used
intentionally in products and processes, due to releases by
manufacturing, use, disposal, recycling, reclamation or
incineration of products;
(Micrograms
per decilitre)
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Cd
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Cadmium is a soft silver-white metal that is usually found in
combination with other elements.
Cadmium compounds range in solubility in water from quite soluble
to practically insoluble
Cadmium occurs as a minor component in most zinc ores and
therefore is a byproduct of zinc production
cadmium is resistant to corrosion
The atomic weight is 112.41 g/mol, the atomic number 48, and the
density of cadmium is 8.64 g/cm3
Cadmium application
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Ni-Cd batteries are
cost-effective well
suited for high power
applications, and
have high cycle lives
Applications for :
industrial batteries
include and portable
batteries
Cadmium emission
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Two major catagories cadmium emissions :
 natural sources
 man-made or anthropogenic sources.
three major compartments of the environment
cadmium emission :
 Air, water, soil
 Emissions to air are considered more mobile than
those to water which in turn are considered more
mobile than those to soils
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Sources and Potential Exposure
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Natural : Weathering and erosion of parent rocks result in
the transport by rivers of large quantities, Volcanic activity is
also a major natural source of cadmium release to the
atmosphere, and Forest fires
Man-made
 Cadmium containing product :Cd-Ni batteries, PVC
products, Cd coated Ferrous products, Cd alloys, Cd
electronic coumpond
 Non cadmium containing products : fossil fuel (oil, coal,
and wood), cement, phosphat fertilizer
 Inceneration of waste material
 Smoking
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Natural cadmium emissions had indicated
approximately 8,000 to 10,000 mt per year for
anthropogenic emissions compared to 800 to 1,000
mt per year for natural cadmium emissions
Background concentration
3
 Atmosphere : 0.1 to 5.0 ng/m
 Earth’s
Crust : 0.1 to 0.5 mg/g
 Marine Sediments : 1 mg/g
 Sea Water : <0.1 mg/L
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The average cadmium content in the world's
oceans has variously been reported Low
Higher levels have been noted around certain
coastal areas (and variations of cadmium
concentration with the ocean depth, presumably
due to patterns of nutrient concentrations, have
also been measured
It may exist in water as the hydrated ion, as
inorganic complexes such as carbonates,
hydroxides, chlorides or sulphates, or as organic
complexes with humic acids
It rapidly adsorbed by particulate matter, and thus
sediment may be a significant sink for cadmium
emitted to the aquatic environment
Distribusi vertikal
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Pola sebaran vertikal logam berat
essensial mengikuti sebaran
nutrient-like (bio-intermediate)
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pencemaran laut
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