Unveiling significant regrowth and potential risk of nontuberculous mycobacteria in hospital water supply system.

The health burden of waterborne nontuberculous mycobacteria (NTM) is a rising concern. While the water supply systems can serve as a potential reservoir for NTM, their abundance, diversity, and transmission pathways remain unknown. This study aimed to characterize the prevalence and regrowth of NTM in building water supply system in a hospital where many M.

Denitrification performance and microbial diversity of immobilized bacterial consortium treating nitrate micro-polluted water.

A heterotrophic denitrification process using bacterial consortium immobilized by polyurethane foams carriers to treat nitrate micro-polluted water was investigated. Nitrate reduction and nitrite accumulation were studied under several factors including initial COD/NO-N concentration ratio, initial pH, initial NO-N/NO-N concentration ratio and inlet NO-N concentration. Batch denitrification experiments showed that nitrate was completely removed at 5 h without nitrite accumulation under the optimum conditions of COD/NO-N concentration ratio of 5.