The Anammox process was developed by the Technical University of Delft and is an innovative treatment process for the removal of ammonium from wastewater. It is a shortcut in the nitrogen cycle in which ammonium is directly converted into nitrogen gas. The Anammox process occurs within one of the many granules present in the reactor. Half of the ammonium is oxidized into nitrite by nitration bacteria. Subsequently, Anammox bacteria convert the nitrite and the rest of the ammonium into nitrogen gas. The whole process takes place in one reactor which makes the Annamox process very compact. In conventional methods, at least two reactors are needed for the nitrification and denitrification steps. Another advantage of the Annamox process is that far less oxygen is required to drive the conversion of the ammonium, which substantially reduces the overall treatment cost. Anammox treatment is particularly suited for industrial wastewater high in ammonium content 🙂


Illustration retrieved from: on the 27th of August 2017

NEWater Singapore

One of Singapore’s four national “water taps” is to reclaim water from wastewater. After years of research, the Public Utilities Board (PUB), Singapore’s national water agency, started to supply high quality reclaimed water, referred to as NEWater. The majority of NEWater is supplied to industries for non-potable purposes. The rest is discharged into reservoirs for indirect potable use. Currently NEWater meets 30% of Singapore’s current water demand, and there are plans to increase this to 50% by 2060. At this moment there are four NEWater treatment plant in service (Bedok, Kranji, Ulu Pandan and Changi). NEWater is produced from treated sewage, termed “used water”, that is further purified in three different steps:

  1. Microfiltration (MF) is the first step in the NEWater production. The treated used water is passed through membranes to filter out and retained on the membrane surface suspended solids, colloidal particles, disease-causing bacteria, some viruses and protozoan cysts.
  2. The second stage of the NEWater production process is known as Reverse Osmosis (RO). In RO, a semi- permeable membrane is used. The semi-permeable membrane has very small pores which only allow very small molecules like water molecules to pass through. Consequently, undesirable contaminants such as bacteria, viruses, heavy metals, nitrate, chloride, sulphate, disinfection by-products, aromatic hydrocarbons, pesticides etc, cannot pass through the membrane.
  3. The third stage of the NEWater production process acts as a further safety back-up to the RO. In this stage, ultraviolet or UV disinfection is used to ensure that all organisms are inactivated and the purity of the product water guaranteed (PUB).

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(Reverse osmosis membranes)

Colloquium Master Thesis

On Thursday the 16th of February 2017, I held my colloquium at Wageningen University of my master thesis covering the sanitation issue in Ciwalengke, Majalaya, Indonesia.

This master thesis research examined the important issues that play a role for successful implementation of domestic sanitation treatment facilities and the potential for nutrient harvesting in Ciwalengke. Based on field observation, water sample analysis, questionnaires and interviews a new sanitation design was proposed specifically for the case of Ciwalengke. It incorporated both a technical and institutional design. The technical design concluded that storage of urine and the treatment of the remaining wastewater through septic tanks were the most feasible technologies. The institutional design concluded that a solid platform would be necessary that incorporates community involvement in the maintenance and operation of the sanitation system. Governmental guidance coupled with a financial structure should be in place to facilitate this process.

It was great to see many students of my year and others attending this 🙂 Thank you all for coming!


IPAL Bojongsoang, Bandung

In October 2016 I was invited to visit the only centralised domestic wastewater treatment plant in Bandung located in Bojongsoang. It was a very interesting day where I saw the many processes that take place within such a treatment plant. In this case, a series of stabilisation ponds were used to treat the incoming wastewater. Check out my short documentary of the processes below!