Edouard Bastarache on wed 2 jul 03
Hello Paul,
more info on attapulgite and lead.
Let us not become scarecrows.
This stuff is useful to rid our
environment of lead.
Preparation of compound granulated adsorbent of attapulgite and studies on
its adsorbability to lead.
Authors:
QIN FEI
XU OUYONG
JIANG TINGDA
Author Address: Dep. Environ. Sci. and Eng., Nanjing Univ., Nanjing 210093,
China.
Source: HUANJING KEXUE; 17 (4). 1996. 47-50, 93.
Abstract:
BIOSIS COPYRIGHT: BIOL ABS. The granulated adsorbent of Attapulgite (AT)
with some additive which includes cement (SN), quartz sands (SS) and steel
crumbs (CS) was researched in order to produce a practical adsorbent for
removal of lead in the waste water. The manufacture progress of granulated
adsorbent and its absorbability were discussed in detail. Optimum adsorbent
is AT-SS among adsorbent of AT-SS, AT-SN and AT-CS. It has a capacity of
adsorbing lead of 500 mg/g under the static conditions and of 60 mg/g under
the dynamic conditions when it was manufactured at a AT-SS mixing ratio of
5:1 and by roasting at a temperature of 700ê C for 120 min. The penetration
time is 20 h and the regeneration rate is 48.3% with the current velocity of
1.5 ml/min. The Pb concentration of effluence is lower than standard within
236 times bed volume at the intake concentration of 200 mg
Abiotic factors affecting the toxicity of lead to fungi.
Authors:
BABICH H
STOTZKY G
Author Address: Lab. Microb. Ecol., Dep. Biol., N.Y. Univ., New York, N.Y.
10003, USA.
Source: APPL ENVIRON MICROBIOL; 38 (3). 1979. 506-514.
Abstract:
HEEP COPYRIGHT: BIOL ABS. The toxicity of Pb to fungi in pure culture was
influenced by several abiotic factors: pH, inorganic anions, clay minerals
and particulate (humic acid) and soluble organic matter. The toxicity of Pb
was potentiated under acidic conditions (pH 5 and 6), and phosphate or
carbonate anions reduced the toxicity, apparently as a result of the
formation of sparingly soluble Pb salts. Clay minerals (montmorillonite >
attapulgite > kaolinite) and particulate humic acid protected against the
toxicity of Pb, presumably as the result of sorption, by cation exchange, of
the Pb to the exchange complexes, which reduced its availability for uptake
by the fungi. Soluble organics, such as tryptone, yeast extract, cysteine,
succinic acid and increasing concentrations of neopeptone, also reduced Pb
toxicity.
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