Biological reductive immobilization of hexavalent chromium using biocatalyst composites

Hlavacek, Nikolaus

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https://hdl.handle.net/2142/122954 Copy

Description

Title

Biological reductive immobilization of hexavalent chromium using biocatalyst composites

Author(s)

Hlavacek, Nikolaus

Issue Date

2024-04-24

Keyword(s)

contaminants

Abstract

Hexavalent chromium (Cr6+) is a known human carcinogen and a common contaminant of drinking water sources. Biological reduction of hexavalent chromium (Cr6+) for the treatment of drinking water sources is reported for a number of microorganisms under various conditions. While much is known about the mechanisms by which bacterial cells can detoxify Cr6+ (by reducing it to trivalent chromium (Cr3+)), the applicability for continuous biological treatment to achieve a low target maximum contaminant level (MCL) at full-scale remains a challenge. This presentation will give an overview of MicroNiche Engineering (MNE) to develop biocatalyst composites for Cr6+ removal in drinking water. Specifically, the technology makes use of a single strain of chromate-reducing organism contained in polymeric composites called MNE biocatalyst. Details of bench-scale testing of MNE packed bed reactors (PBRs) will be covered, including optimization of parameters such as hydraulic retention time (HRT) and nutrient dose to achieve continuous chromium removal to less than the maximum contaminant level of 10 parts per billion (ppb). The PBRs have demonstrated 80% reduction in Cr6+ with influent concentrations of up to 50 ppb under a two-hour HRT. The mass balance, fate of reduced chromium, and plans for scale-up and pilot testing will be discussed.

Type of Resource

• still image
• text

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