Creating an enabling environment for WR&R implementation.

Reclaimed water is receiving growing attention worldwide as an effective solution for alleviating the growing water scarcity in many areas. Despite the various benefits associated with reclaimed water, water recycling and reuse (WR&R) practices are not widely applied around the world. This is mostly due to complex and inadequate local legal and institutional frameworks and socio-economic structures, which pose barriers to wider WR&R implementation. An integrated approach is therefore needed while planning the implementation of WR&R schemes, considering all the potential barriers, and aiming to develop favourable conditions for enhancing reclaimed water use. This paper proposes a comprehensive methodology supporting the development of an enabling environment for WR&R implementation. The political, economic, social, technical, legal and institutional factors that may influence positively (drivers) or negatively (barriers) WR&R implementation in the regional water systems are identified, through the mapping of local stakeholder perceptions. The identified barriers are further analysed, following a Cross-Impact/System analysis, to recognize the most significant barriers inhibiting system transition, and to prioritize the enabling instruments and arrangements that are needed to boost WR&R implementation. The proposed methodology was applied in the Copiapó River Basin in Chile, which faces severe water scarcity. Through the analysis, it was observed that barriers outweigh drivers for the implementation of WR&R schemes in the Copiapó River Basin, while the key barriers which could be useful for policy formulation towards an enabling environment in the area concern the unclear legal framework regarding the ownership of treated wastewater, the lack of environmental policies focusing on pollution control, the limited integration of reclaimed water use in current land use and development policies, the limited public awareness on WR&R, and the limited availability of governmental funding sources for WR&R.

On-line load monitoring of wastewaters with a respirographic microbial sensor.

This paper demonstrates the functionality, laboratory testing and field application of a microbial sensor that is capable of monitoring the organic pollution extent of wastewaters both off-line in a laboratory and on-line in a wastewater treatment plant. The biosensor was first developed in the laboratory using synthetic wastewater and then applied to monitor the effluent of the unit. The basic working principle of the biosensor is based on the on-line measurement of CO2 concentration in the off gas produced during carbon compound degradation by microbial respiration activities. CO2 concentration under operation conditions (constant oxygen flow rate, residence time and pH) is closely related to the extent of organic pollution (biochemical oxygen demand, chemical oxygen demand). CO2 monitoring is carried out by an infrared spectrometer, whereas current organic pollution is determined off-line according to the conventional 5-day lasting BOD analysis. Off gas analysis of CO2 concentration strongly correlates with off-line biochemical oxygen demand measurements allowing continuous on-line monitoring of the organic load within a wastewater treatment plant. Thus, real time process control and operation become feasible.