The combination of microbial reduction and further microbial oxidation of iron was applied to the treatment of food-processing wastewater and recovery of ammonium. Fe2+ ions were formed by ironreducing bacteria under anaerobic conditions. Ammonium was recovered by co-precipitation with negatively charged iron hydroxides produced during oxidation of Fe2+ by iron-oxidizing bacteria under microaer...

Achieving nitrogen removal from domestic wastewater using anaerobic ammonium oxidation (anammox) has the potential to make wastewater treatment energy-neutral or even energy-positive. The challenge is to suppress the growth of nitrite-oxidizing bacteria (NOB). This study presents a promising method based on intermittent aeration with low dissolved oxygen to limit NOB growth, thereby providing a...

In an agroindustrial wastewater pond, a naturally occurring unicellular microalga, Chlorella vulgaris, was closely associated with the terrestrial plant-associative N2-fixing bacterium Phyllobacterium myrsinacearum. When the two microorganisms were artificially coimmobilized in alginate beads, they shared the same internal bead cavities, and the production of five microalgal pigments increased,...

The development of titrimetric sensor applications to monitor biological wastewater treatment processes is shortly described, and the measurement principle (based on a pH controller) is illustrated. 3 applications that were developed during the past years are used to illustrate the capabilities of titrimetric sensors. The ammonium and the nitrate concentration can be measured to monitor the nit...

Nitric oxide production was measured during nitrification in a laboratory-scale bioreactor, operated at conditions relevant to municipal nitrifying wastewater treatment plants. This study aims to determine which type of microorganism and which metabolic pathway is responsible for nitric oxide emission during nitrification. Simulation studies were used to identify which pathway is the main sourc...

A combination of microalgae (Chlorella vulgaris or C. sorokiniana) and a microalgae growth-promoting bacterium (MGPB, Azospirillum brasilense strain Cd), co-immobilized in small alginate beads, was developed to remove nutrients (P and N) from municipal wastewater. This paper describes the most recent technical details necessary for successful co-immobilization of the two microorganisms, and the...

This study contributes to the improvement of low-cost biotechnology for wastewater treatment in constructed wetlands (CWs). Constructed wetlands are energy efficient engineered systems that mimic the treatment processes of natural wetlands, removing polluting organic matter, nutrients, and pathogens from water. The aim of this study was to investigate the advisability of the inoculation of hori...

Excess nitrogen components must be removed from wastewater to protect the quality of the water bodies that it will be eventually discharged to. A conventional wastewater treatment system for nitrogen removal is often involved with two processes, nitrification and denitrification. Nitrification is mostly achieved by complete oxidation of ammonium (NH4+) to nitrite (NO2-) by the appropriate aerob...

The nutrient removal efficiency of Chlorella vulgaris cultivated in domestic wastewater was investigated, along with the potential to use membrane filtration as a pre-treatment tool during the wastewater treatment process. Chlorella vulgaris was batch cultivated for 12 days in a bubble column system with two different wastewater treatments. Maximum uptake of 94.18% ammonium (NH₄-N) and 97.69% o...