Technical features

Membrane technology in controlling micropollutants and pathogens

The challenge posed by micropollutants and pathogens is of huge interest. Our online discussion event, attended by 30 people from across the world and hosted by Graeme Pearce and Simon Judd, in April 2021 assessed the current status. Read our full report.

Combined hydrothermal carbonization with anaerobic digestion: recycling of the HTC products

Clogging mitigation through MBR membrane module design

Some clogging occurs in most MBR systems regardless of membrane module type or geometry. Prevention or control measures are typically considered at the system design level and during operation but even with adequate pre-treatment, clogging can still occur.

An introduction to water and wastewater treatment technologies

The treatment of water or wastewater relies on a number of individual unit operations combined to make a process. The same underpinning mechanisms, either physical or chemical in nature, apply to the process whatever the type of water or wastewater.

The integrated fixed-film activated sludge membrane bioreactor (IFAS-MBR): comparison with a regular MBR for nutrient removal

The IFAS-MBR process is less well explored than the MBBR-MBR. It is of interest to establish the performance of the IFAS-MBR when challenged with a variable influent C/N ratio, as this affects nutrient removal and the emission of N2O – a highly active GHG.

Ragging in MBRs − how do rags form?

Ragging is a type of clogging, where clogging relates to agglomeration of solids in the membrane tank. In the case of ragging, filament solids from textile materials join together to form long braids which are mechanically stable in the mixed liquor.

UK water net zero carbon: the true benefit of biosolids to land

In 2019, the UK introduced its 2050 net zero target amendment to the Climate Change Act (2008). A year on, the Committee on Climate Change’s 2020 progress report revealed that the UK is already far off-course, with just 1 of 25 critical policies delivered.

Energy reduction at a large-scale MBR: the Nordkanal experience

Energy consumption is the most significant cost and contributor to environmental impact during MBR operation. The plant at Kaarst-Nordkanal highlights the impact of the on-site installation of AD on energy consumption and greenhouse gas emissions.

Protect and survive: the fate of pathogens in stored sludge

Emphasis on the circular economy and extracting value from waste has focused attention on the pathogen content of biosolids (i.e. treated wastewater sludge) intended for reuse in agriculture, based primarily on E. coli as an indicator micro-organism.

Biochar: the new black gold?

Biochar is the organic solid char product from biomass pyrolysis, i.e. thermal treatment in a (mostly) oxygen-free atmosphere. It has many potential uses, e.g. as an adsorbent for pollutant removal, but its main application is in agriculture.

Sludge-to-energy recovery methods − a review

A comparison of anaerobic digestion and combustion with two more novel oxygen-deficient thermochemical processes (pyrolysis and gasification) for resource recovery from sewage sludge reveal the challenges to the implementation of these technologies.