Meniscus news and blog articles

Read the latest Meniscus news and blog articles on big data, analysis, research, how-to, opinions, data management and videos.

What is the FM Ratio

One of the most fundamental control parameters for the activated sludge process is the relationship between the load (i.e. kg/day as opposed to mg/l) of BOD (or bacterial ‘food’) entering the aeration plant, and the ‘mass’ of bacteria in the aeration tank available to treat the incoming BOD.


Environmental concerns about the release of greenhouse gases to the atmosphere, and issues of global warming and climatic change regularly feature in the media. What is often not referred to in these stories is the role of wastewater treatment.

Dosing Syphons

At all rates of flow to the treatment works rotary distributors must be fed at rates sufficient to ensure that the jets of sewage will rotate the arms. If the flow to the distributors is too low they might stand still and dribble.

Reed Bed Design Factors

Reed beds are a tertiary treatment with the process aim of removal of suspended and dissolved matter beyond that which the conventional secondary sewage treatment process provide. They remove 60 – 80% solids from the secondary effluent.

How Activated Sludge Works

The Activated Sludge (AS) process was developed as an alternative to biological filters, and is particularly useful for large populations where land is at a premium. More recent research however, has shown that the process can be operated in many different modes, making it a more flexible process than biological filtration.

Loading of conventional biological filters

The rate at which sewage can be treated on a biological filter will depend on the nature of the sewage and the required effluent quality. Loading rates are best measured in terms of organic loading, kg of BOD per cubic metre per day, often abbreviated to kg/m3/d.

Connecting to the Niagara framework using the Obix framework

We have had the ability to connect to BMS systems running the Niagara Framework for a while now….but not making the most of this technology.