This paper presents a very useful software tool to design, simulate and optimise wastewater treatment plants. The program is called DESASS (DEsign and Simulation of Activated Sludge Systems) and has been developed by CALAGUA research group. The mathematical model implemented is the Biological Nutrient Removal Model No.1 (BNRM1) which allows simulating the most important physical, chemical and b...

We developed a model for nutrient removal in an aerobic granular sludge system. This model can quantitatively describe the start-up of the system by coupling a model for studying the population dynamics of the granules in the reactor (reactor-scale model) and a model for studying the microbial community structure in the granules (granule-scale model). The reactor-scale model is used for simulat...

iNTroducTioN The discharge of reactive nitrogen (N) and phosphorus (P) into water bodies is unwanted as it accelerates the process of eutrophication. To avoid discharge of these nutrients, energy and resources in the form of aeration (for nitrification), organic carbon (for denitrification and/or enhanced biological phosphorus removal (EBPR)), and chemical precipitants (e.g., ferric, alum, lime...

Advances in wastewater treatment over the past 150 years have improved public health and local water quality. Recently however, society has begun to consider the wider environmental implications of these improvements. This paper uses life cycle assessment to quantitatively compare the environmental costs and benefits of different wastewater treatment technologies and standards. It is demonstrat...

The prevalence of various pollutants like nitrogenous, sulphurous, phosphorous compounds, heavy metals, and organic compounds has seriously threatened the sustainability of natural ecosystems and is thus interfering with the natural biogeochemical cycling. Chemical pollution of water bodies can cause serious damage to environmental quality because many of these pollutants are extremely toxic an...

Mitigating the global expansion of cyanobacterial harmful blooms (CyanoHABs) is a major challenge facing researchers and resource managers. A variety of traditional (e.g., nutrient load reduction) and experimental (e.g., artificial mixing and flushing, omnivorous fish removal) approaches have been used to reduce bloom occurrences. Managers now face the additional effects of climate change on wa...

background: this study assessed the removal of organic material and nutrients from full-scale subsurface flow (ssf) constructed wetlands (cws) followed by anaerobic stabilization ponds under environmental conditions. methods: the effluents were distributed evenly in 12 reed beds. samples were taken twice monthly for a total of 6 months from several points in the wetland. biochemical oxygen dema...

Two sequencing batch reactors, one with the conventional anoxic and aerobic (AO) process and the other with the multiple AO process, were operated to examine characteristics of biological nitrogen removal, especially of the multiple AO process. The long-term operation showed that the total nitrogen removal percentage of the multiple AO reactor was 38.7% higher than that of the AO reactor. In th...

A biological nutrient removal (BNR) activated sludge (AS) scheme incorporating external nitrification in a fixed media system is evaluated. A laboratory scale investigation of the scheme indicates that it holds considerable potential for BNRAS system intensification through major reduction in sludge age and oxygen demand and significant improvement in sludge settleability. Because the BNRAS sys...