The assimilation of inorganic N, in the form of ammonia, onto C skeletons for the production of amino acids is one of the most important biochemical processes in plants. In an actively growing plant, N is taken up as nitrate and to a lesser extent as ammonia. Nitrate is reduced in the cytoplasm by nitrate reductase and nitrite enters the chloroplasts where it is further reduced before incorpora...

In the paper, control possibilities for the nitrogen removal process within activated sludge wastewater treatment plants are discussed. A predictive controller is introduced which aims to reduce the peaks in effluent concentration for ammonia nitrogen. Additionally, the controller improves the overall nitrogen removal using less aeration energy. A parsimonious deterministic model is used for th...

This paper presents the results of five years monitoring of an experimental wastewater treatment plant in southeast Brazil, comprised of a UASB reactor followed by a submerged aerated biofilter (BF) (field scale) and shallow polishing ponds (pilot scale). Three ponds in series achieved high quality effluent standards in terms of ammonia and E.coli, but a fourth pond did not result in further ef...

Many Indian ammonia plants struggle with high feedstock prices. In order to survive in the competition from new plants in areas with low gas cost, many plant owners of existing plants have decided to revamp their plants to reduce the energy consumption and/or increase the capacity. New developments are needed in order to fulfil these needs of the market. This paper will highlight some of the de...

An optimal operating condition for ammonia removal at low temperature, based on fully coupled activated sludge model (FCASM), was determined in a full-scale oxidation ditch process wastewater treatment plant (WWTP). The FCASM-based mechanisms model was calibrated and validated with the data measured on site. Several important kinetic parameters of the modified model were tested through respirom...

A mathematical model is developed and tested with plant data for the ammonia cold shot converter of Razi Petrochemical Complex. The model is based on a material and energy balance in a differential element of beds and is subjected to the assumptions of uniform distribution of temperature and composition through a general cross section and negligible mass and heat transfer in axial direction. Th...