Optimize the measurement of Poly-hydroxy-alkanoates (PHA) in biomass

Poly-hydroxy-alkanoate (PHA) is an intracellular polymer that can be used as an energy and carbon source by microorganisms. Measuring PHA is important for understanding the microbial metabolism of enhanced biological phosphorus removal (EBPR) and aerobic granular sludge (AGS) systems. There is a commonly used method to measure PHA, which is...

Glucose conversion by aerobic granular sludge

Aerobic granular sludge (AGS) is an innovative biotechnology extensively applied for treating municipal wastewater, and it can potentially treat sugar industry wastewater. Glucose is a prevalent substrate in sugar industry wastewater; nevertheless, the effect of glucose on AGS systems remains unexplored. In this study, an AGS reactor using...

Effect of Substrate Concentration & Elevated CO2 Partial Pressure on the Odd & Even Carboxylate Formation

Of all the greenhouse gases (GHGs), carbon dioxide (CO2) has been the target of most climate recovery efforts as it is the most abundantly emitted GHG by mass. In fact, in 2015 a legally binding international treaty was adopted by 196 parties in Paris, France to constrain the anthropogenic warming to 1.5-2.0˚C above the pre-industrial level. In...

Anoxic Iron Sulfides Formation: A Novel Approach for Iron Removal in Groundwater Treatment

Groundwater (GW) makes up roughly half of the global drinking water supply. Conventional iron removal in GW treatment produces approximately 10,000t/d of iron sludge. Iron sludge consists of low-density flocs with low to no commercial value and causes frequent energy intensive backwashing of the rapid sand filter. This study aimed to explore the...

Criteria interdependency in Multi-criteria Decisionmaking on sustainability: Desalination for resource recovery case study

There is a rising concern on the sustainability of Zero Liquid Discharge (ZLD) desalination. In this study, Multi-criteria Decision-making (MCDM) is applied to compare the sustainability performance of various ZLD scenarios, which is part of a Strong Sustainability (SS) assessment of desalination. ZLD desalination systems are considered to be...

Economic and cost-effectiveness analysis of integrated desalination and brine treatment systems

The brine generated from desalination is a threat to the environment, and its disposal has been a great challenge. A new concept Zero liquid discharge (ZLD) can minimize the environmental impact of brine. However, the high costs for construction and running of a ZLD plant limits its growth in desalination market. Therefore, a new strategy...

Anaerobic digestion of alkaline Kaumera Nereda® gum waste residual sludge at pH 9.6 and 0.6 M Na+ to produce CO2-free green gas

The first full-scale Kaumera extraction plants are in operation and increases the circularity of WWTP already. However, to reach a goal of zero waste production it is necessary to look into the waste stream of the Kaumera extraction itself. Roughly 30% of organics is extracted in the process and the remaining organics in the waste can be further...

The Case of Re-plex: Wastewater to Building material: Life Cycle Assessment on the use of Re-plex as interior finishing material

With the increasing focus from policymakers to a circular economy, assessing the environmental impacts of circular products is becoming more important. In this thesis a Life Cycle Assessment of the new circular composite Re-plex is performed. The Re-plex can be used as building material. Re-plex is produced from Kaumera Nereda® Gum recovered...

Genomic profiles and removal mechanisms explain the observed stratification of Fe²⁺, NH₄⁺ and Mn²⁺ removal in rapid sand filters

Groundwater is an excellent source for the production of drinking water due to its low concentration of microorganisms and contaminants. The main contaminants present in groundwater are iron, ammonium and manganese, which are sequentially removed in rapid sand filters by a combination of biological and chemical processes. Currently, limited...

Effect of sodium chloride on the formation of ice and salt during eutectic freeze crystallization of sodium sulfate with a scenario study of real brine

Brine streams from industry is a burden to the environment if not disposed properly. “Zero liquid discharge” (ZLD) is an ideal way of converting saline streams from waste to resource through multiple membrane-based or thermal-based treatment technologies. The utilization of the recovered resource minimizes both costs and environmental impacts....

The effect of anaerobic influent contact regime on granulation

Nowadays the use of aerobic granular sludge, also known as Nereda™ in municipal wastewater treatment, is applied worldwide. The next innovation in for this technology is the implementation of granular sludge in continuous flow through configuration. However, many challenges will have to be faced before this technology can be applied in full...

Characterisation of storage polymers during anaerobic digestion in haloalkaline conditions

The goal of this experiment has been to characterize storage polymers produced during anaerobic digestion under haloalkaline conditions. The project focused on three research questions: the type of storage polymers produced, which conditions selected for the production of storage polymers and which organisms are responsible for the production of...

The quest for specialist N2O-respiring bacteria

Nitrous oxide (N2O) is a potent greenhouse gas, and its stratospheric concentration is already 20% above the pre-industrial level. Over 70% of N2O is produced by microbial processes. Nitrous oxide reductase is the only enzyme able to reduce N2O to innocuous N2. The high abundance of organisms harbouring it and lacking the genetic potential to...

Reactor characterization and the application of biological selective pressure for granulation in a CAGS pilot

Treatment of wastewater with aerobic granular sludge (AGS) has major advantages compared to activated sludge. The only commercial system that uses AGS is the Nereda® batch process. The disadvantage of this system is the lack of existing infrastructure. AGS in continuous systems could be a solution to this disadvantage. That’s why the HARKOS...

Nanocellulose from wastewater solids: A biorefinery perspective

Cellulose is a biopolymer commonly used as a renewable constituent in the production of green materials. Wastewater solids can be an attractive source of cellulose, mainly originating from toilet paper. Cellulosic solids can be recovered (i) through sieving before the sewage treatment - resulting in a Fine Sieve Fraction (FSF), or (ii) after...