Modelling of biological nitrogen removal during treatment of piggery wastewater.

During this study, a mathematical model simulating piggery wastewater treatment was developed, with the objective of process optimisation. To achieve this, the effect of temperature and free ammonia concentration on the nitrification rate were experimentally studied using respirometry. The maximum growth rates obtained were higher for ammonium-oxidising biomass than for nitrite-oxidising biomass for the temperatures above 20 degrees C; values at 35 degrees C were equal to 1.

Modelling of biological processes during aerobic treatment of piggery wastewater aiming at process optimisation.

A dynamic mathematical model was developed for the simulation of the aerobic treatment of piggery wastewater. This model includes the carbon oxidation, the nitrification and the denitrification. According to the experimental results obtained during this study, a modified version of the activated sludge model No.

Piggery wastewater characterisation for biological nitrogen removal process design.

In intensive farming areas, the design of biological nitrogen removal plants for piggery wastewater requires the determination of the chemical oxygen demand (COD) fractions of the effluent. For this purpose, an experimental procedure was developed to quantify the inert soluble (SI) and particulate (XI) COD fractions, as well as the readily (SS) and the slowly (XS) biodegradable COD fractions. For the four wastewaters tested, the SI and the XI fractions were equal to 3-4 g O(2)l(-1) and 17-28 g O(2)l(-1), respectively, which resulted in a total inert fraction of 42-84% of total COD.

Activated Sludge Model No. 1 calibration for piggery wastewater treatment using respirometry.

To optimise the intermittent aeration process for piggery wastewater, the Activated Sludge Model No. 1 needs to be calibrated and adapted to this specific effluent. By combining aerobic and anoxic respirometric tests, biodegradation kinetics of organic fractions in piggery wastewater could be studied.