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Aerobic granular sludge technology can be regarded as the future standard for industrial and municipal wastewater treatment. As a consequence, a growing number of institutes and universities focus their scientific research on this new technology. Recently, after extensive Dutch research and development effort, an aerobic granular biomass technology has become available to the market. Full scale installations for both industrial and municipal applications are already on stream, under construction or in design. The technology is distinguished by the name ‘Nereda®’ and based on the specific characteristics of aerobic granular sludge. It can be considered as the first mature aerobic granular sludge technology applied at full scale. It improves on traditional activated sludge systems by a significantly lower use of energy and chemicals, its compactness and its favorable capital and operational costs.

Aerobic granular sludge is seen as the future standard for industrial and municipal wastewater treatment. Through a Dutch research and development program, a full-scale aerobic granular biomass technology has been developed – the Nereda® technology – which has been implemented to treat municipal and industrial wastewater. The Nereda® system is considered to be the first aerobic granular sludge technology applied at full-scale and more than 40 municipal and industrial plants are now in operation or under construction worldwide. Further plants are in the planning and design phase, including plants with capacities exceeding 1 million PE. Data from operational plants confirm the system's advantages with regard to treatment performance, energy-efficiency and cost-effectiveness. In addition, a new possibility for extracting alginate-like exopolysaccharides (ALE) from aerobic granular sludge has emerged which could provide sustainable reuse opportunities. The case is therefore made for a shift away from the ‘activated sludge approach’ towards an ‘aerobic granular approach’, which would assist in addressing the challenges facing the wastewater treatment industry in Asia and beyond.

The condensation of Fe atoms was studied over the temperature range of 670-1150 K at pressures between 0.3 and 0.45 bar behind incident shock waves based on Fe concentration measurements. Atomic resonance absorption spectroscopy was applied to follow Fe atoms in gas mixtures containing Fe(CO) 5 as iron precursor, highly diluted in argon. At the upper experimental temperature limit, the experiments showed constant Featom concentration levels after decomposition of the precursor. At a lower temperature, a time dependent decrease of the Fe concentration was observed showing an inverse temperature dependency. A simplified reaction mechanism consisting of a one step decomposition of the precursor and various iron consumption reactions was proposed for the simulation of the signals. The major initial reactions for the understanding of the condensation process were found to be the formation and the decomposition of Fe 2 (see reactions R2 and R3 in the text). The rate coefficients of both reactions were determined experimentally to be k 2 ) 10 19 cm 6 mol -2 s -1 and k 3 ) 10 19.63(0.40 exp(-17800 ( 700 K/T) cm 3 mol -1 s -1 (for reactions R2 and R3, respectively).

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