Author(s)

J. Bayo, J. M. Angosto, J. Serrano-Aniorte, J. A. Cascales- Pujalte, C. Fernández-López & J. López-Castellanos

Abstract

A study of physicochemical parameters in a municipal wastewater treatment plant was undertaken to consider the presence of bulking phenomena by means of statistical and logistic regression analyses. There appears to be an important effect on activated sludge settleability that can be related to the temperature of wastewater. Besides, there were significant differences between the percentage of nitrogen removal from the secondary treatment with the season. The SVI increased with conductivity, meanwhile BOD5 removal decreased with this parameter. The development of logistic regression models identified two statistically significant variables that appeared to be important to the contribution of a higher SVI: season and pH. Keywords: wastewater, physicochemical parameters, bulking, modelling. 1 Introduction Wastewater treatment plants are complex systems, with different physicochemical and biological phenomena taking place simultaneously. Wastewater collected from municipalities and communities must ultimately be returned to receiving waters or to the land [1]. Besides, due to the limited water resource, a great attention is being paid into reclamation and reuse of wastewater from municipalities mainly for irrigation [2]. In all cases, water quality standards are becoming more and more stringent.

Keywords

wastewater, physicochemical parameters, bulking, modelling.