Introduction

SCELSE capitalises on its capacity to map microbial systems on all levels in its two integrated programs that utilise the expertise and facilities of all four clusters to understand and harness biofilm systems in applied engineering settings. The integrated programs focus on the role of biofilms in the water cycle: (1) the Ulu Pandan Water Reclamation Plant treating used water of mostly domestic use origin, and (2) Urban waterways - a model system of streams and canals in the Ulu Pandan catchment area. These programs highlight SCELSE's strength in bringing together different fields of expertise in a unified approach to deliver a comprehensive understanding of all aspects of a system.

1. Ulu Pandan Water Reclamation Plant (UPWRP)

Ulu Pandan Water Reclamation Plant

Ulu Pandan Water Reclamation Plant is one of numerous full-scale public works in Singapore that treat used water. Microbial processes in the biological reactor remove nutrients and organic carbon to produce clean water that is either discharged into the sea or reused for industrial applications.

Typically, the microorganisms involved in such plants are unknown, but for the Ulu Pandan plant our researchers probe the functions and dynamics of all bacteria in the reactor with cutting-edge molecular, bioinformatics and systems ecology tools.

Imagine a sports team where neither the players nor their positions are completely known and even the rules of the game are insufficiently understood. To understand the potential peak performance of these athletes – the bacterial species involved - SCELSE researchers work in close cooperation with the plant operators to study the evolution of genes in the plant and their expression under different conditions, so that process performance and energy conservation can be optimised in the treatment of used water.

2. Urban Waterways

SCELSE has adopted the Sungei (river) Ulu Pandan catchment (Singapore) as a model to study the microbial processes and geochemistry in urban waterways. The Sungei Ulu Pandan catchment is ideal to study these processes with its 20km2 size encompassing residential, vegetated and industrial land use patterns, low tidal impact and minimal influences from random access by public. In addition, laboratories and test-bedding facilities are available for scale-up analyses.

Initial studies of the microbial and geochemical processes are beginning to provide SCELSE with insights into the functioning of urban waterways. Although major and minor canals provide opportunities for transportation and mixing of sediments, chemicals and microbes, small drains collecting water from their immediate catchment areas possibly act as isolating barriers by restricting such mixing. These canals are dominated by microbial and ecological processes adapted to different land uses. Our results on the dominance of organic degradation and metals resistance genes indicate microbes respond to the urban pressures arising from human activities. Studies conducted by SCELSE will help provide fundamental knowledge related to the reshaping of waterways by a combination of hard and soft engineering approaches.

Water enters the Sungei Ulu Pandan river system	Stormwater drains	Intermediate	Major canals