Cadmium removal and sorption by benthic microbial biomats and potential applications for a contaminated watershed in the Arequipa region of southern Peru

Heavy metal pollution of waters and wastewaters is of worldwide concern, threatening both human health and the environment. One region that has been impacted by heavy metal contamination, is the Tambo River Basin, an agricultural area in the Arequipa Region of Southern Peru. This two-part study includes a watershed-scale evaluation and synthesis of existing water quality data from disparate sources to identify metals of concern in the watershed and batch-scale treatment studies using benthic microbial biomats. Several metals of concern were identified, including arsenic, boron, cadmium, copper, lead, nickel, and zinc, occurring at concentrations above permissive limits for water quality, such as agricultural use. Cadmium was selected as a model metal for treatment with wetland microcosms and sorption using biomat material from the Prado Wetlands in Orange County, California, and the Mines Park wetland reactor at Colorado School of Mines. The two types of biomat were characterized for organic content as volatile suspended solids which were approximately 4-5 times greater for Mines Park biomat than the Prado. Preliminary batch microcosm experiments decreased the concentration of cadmium to below agricultural water quality limits. To better understand cadmium removal for the two types of biomat, sorption isotherms were generated using the Freundlich model. Comparison of Freundlich coefficients for the two types suggest that the Mines Park biomat has a higher sorption capacity which may be due to higher organic content. Comparison with similar sorbents like activated sludge suggests that the biomat could be considered as a sorbent for cadmium sequestration. Batch microcosm and sorption experimental results indicate that the biomat may be applied as a treatment alternative for heavy metals in the Tambo River Basin.

Name thesis:degree_name

Master of Science (M.S.)

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Civil and Environmental Engineering

Grantor dc:publisher

Colorado School of Mines. Arthur Lakes Library

Year dc:date.issued

2021

Author dc:creator

• Acker, Sarah

Advisor dc:contributor.advisor

• Sharp, Jonathan O.

Committee members dc:contributor.committeemember

• Vanzin, Gary
• Ranville, James F.

Statement dc:rights

• Copyright of the original work is retained by the author.

Language dc:language.iso

eng, English

Identifier

T 9229

OAI identifier oai:identifier

oai:repository.mines.edu:11124/14251