عنوان

Bioavailability of cadmium in municipal sewage sludge

Number

TLpq303896413

.Language of Text, Soundtrack etc

انگلیسی

Title Proper

Bioavailability of cadmium in municipal sewage sludge

General Material Designation

[Thesis]

First Statement of Responsibility

J. Jing

Subsequent Statement of Responsibility

T. J. Logan

Name of Publisher, Distributor, etc.

The Ohio State University

Date of Publication, Distribution, etc.

1990

Specific Material Designation and Extent of Item

317

Dissertation or thesis details and type of degree

Ph.D.

Body granting the degree

The Ohio State University

Text preceding or following the note

1990

Text of Note

Seventeen sludges were selected based on their Cd and P content. These sewage sludges were obtained directly from waste water treatment plants with total Cd contents ranging from 0.07 to 2.02 mmol/kg and were extracted by three methods using a sludge-to-solution ratio of 1:5. The extractants employed were: 0.05 M Ca(NO3)2, 0.05 M Ca(NO3)2 containing 5 usd\timesusd 10 M Na-EDTA, and 1 g Chelex 100 resin. Cd was speciated using the computer program, GEOCHEM, after measuring the major cations and ligands in the extraction solutions. Extractable Cd and Cd species were compared with Cd uptake by sudax, a sorghum x sudan hybrid (Sorghum bicolar, L. (Moench)), which was started in pots of acid-washed quartz sand. After the roots completely penetrated the sand, the pots were placed on soil/sludge mixtures containing 1.25 and 2.5 mg Cd. Uniform plant growth was maintained with a neutral nutrient solution specifically developed for grass growing in sand. Plant tops were harvested 6 weeks after transplanting and analyzed for total Cd. Paired comparisons across all three extraction methods gave a uniformly high correlation (R2 usd\congusd 0.97). Cd concentration in plants increased with Cd rate but the slopes were different for different sludges. Cd uptake was positively correlated with total sludge Cd concentration (R2 = 0.46), and with Cd extracted with Ca(NO3)2 (R2 = 0.91), with Ca(NO3)2 containing EDTA (R2 = 0.94), and with resin (R2 = 0.92) extraction. No single Cd species gave as high a correlation to plant uptake as the total Cd concentration in that extraction solution. A correlation between Cd uptake and Cd/P showed that, as the sludge P content increased, the bioavailability of Cd decreased. Resin extraction, which gives a strong positive correlation, is recommended as a highly reliable and convenient method for estimation of Cd bioavailability for routine analyses.

Agricultural chemicals

Earth sciences

Environmental science

Geochemistry

Health and environmental sciences

Pure sciences

J. Jing

T. J. Logan

Electronic name

p

[Thesis]

276903

a

Y