Building with Nature

The Netherlands constantly has to battle against the threat of flooding from the ocean and rivers as a vast area of its land is below sea level. However, the last major flood was way back in 1953. The success of water management in Netherlands is largely rooted in careful spatial planning and ‘building with nature’ to achieve a resilient flood-proof landscape. The concept of Building with Nature was invented by the the Dutch water authority, Rijkswaterstaat, and several other research institutes and consultancy agencies. The concept basically develops waterworks by integrating infrastructure, nature and society for sustainable water management solutions. Working with nature, rather than against it, is seen as being more efficient and less costly. One such example is giving room to the river “ruimte voor de rivier“. During peak discharges, usually in winter and spring, the river has special designated areas along its banks where water can be stored and transported. These so called uiterwaarden or flood plains in English are of low commercial values with almost no buildings being built on them. In this way, the (financial) damage the river can cause is minimal. During normal water levels, these areas are normally used for recreation and cattle grazing.

In the picture and clip below you can see the river Waal near Nijmegen which has been fed large amounts of rain and meltwater from Switzerland and Germany in recent weeks. Despite it looking rather serious, the situation is very much under control as the flood plains are compensating for the high water level. It shows that Building with Nature is the way to go!


The Importance of Phosphate Recovery

Sooner or later, worldwide phosphate reserves will be depleted. Currently, phosphate is seen as a pollutant due to the high amounts phosphate run-off from agricultural lands. In the future, however, phosphate will become a strategic resource since it is only available in limited amounts. It is highly essential that society starts establishing ways of recovering this valuable resource. Phosphate is essential for people, animals and plants as its incorporated in DNA, bones, ATP and enzymes. Annually, 40 million tons of phosphate are mined mainly in Morocco, China and USA. The total world reserves are estimated between 3600-8000 million tons. The production of artificial fertilizer uses by far the most amount of phosphate. 80% of the world phosphate consumption is used for the production of artificial fertilizer. From this, it is clear that in the agricultural sector there needs to be a fundamental mind-switch towards recovering phosphate. Research shows that more than half of the applied phosphate on agricultural fields is lost through run-off and leaching…what a waste!! The recovery of phosphate not only recovers a vital element for life on earth, but it also reduces pollution loads into the environment.

(Obtained data from Wageningen World Magazine, Nr. 4, 2017).

Orange ASEAN, Jakarta

Last week I participated in the fifth edition of Orange ASEAN, this time in Jakarta! Orange ASEAN is an intensive 3-week consultancy project for young professionals, entrepreneurs and master students from the Netherlands and Southeast Asia designing innovative solutions for sustainability challenges in ASEAN countries. In interdisciplinary teams, participants work together in dedicated teams developing business cases for real-life issues. My team consisted of Tulus (Indonesia), Dawn (Singapore) and Sukumal (Thailand) with Royal HaskoningDHV as our client. They asked us to developed innovative solutions to Indonesia’s water challenges…very broad for a 3-week consultancy project! In the end we narrowed the scope down and came up with two products that were well received by our client: Smart Water ANalytics (SWAN) and a Technical Advive Platform (TAP). Massive thanks to the team for making the past 3 weeks so enjoyable! We really gelled and produced some interesting stuff 🙂

Profitability in Aquaponics

To grow vegetables in water from a fish pond full of nutrients might sound like a brilliant idea, but is it really profitable? A study by reaearchers from the Wageningen Univesity showed that more than half of the 1000 commercial aquaponic farms worldwide make a loss. This was mainly the result of low market value for the produced vegetables and fish that were farmed. Before starting an aquaponics farm it is important to look at the market prospects. A niche in the market needs to be found that could make aquaponics more profitable. Tilapia and catfish usually won’t make it because they sell for far to cheap. Perch, burbot and pike could be interesting alternatives for the European market as their market value is much higher.

Schematic overview of a aquaponic system. Illustration retrieved from Baliga Lab, Institute for Systems Biology


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

Aircon condensation for irrigation

Ever noticed the wet puddle outside your aircon? Each time an air conditioner is turned on, it pulls moisture from the air inside the home. The water needs to go somewhere and is usually discharged via a condensation pipe to the nearest drain. 

Why not capture this free water and use it for irrigation to plants?! You simply have to divert the condensation pipe to the area you would like to keep moist. Small droplets from the condensation pipe will keep the soil moist all day long. It is very similar to drip irrigation! Moreover, the water from the aircon is cold which cools the plants. Amazing and simple guys! 😊

Engineering with Membranes 2017

Between the 26th and 28th of April the annual Engineering with Membranes was held in Singapore organised by the Singapore Membrane Technology Centre (SMTC). The main goal of the conference was to share knowledge on recent advances in membrane science and technology. Leading membrane specialists from around the world gave a total of 70 lectures covering desalination, reclamation & resource recovery, molecular separation, membrane fouling, gas separation, pre-treatment, industrial & bioprocess application and membrane monitoring. The Dutch representative at this conference was Dr. Emile Cornelissen, senior researcher at KWR, who presented his research on controlling Reverse Osmosis (RO) fouling after minimal pre-treatment. His main conclusion was that the 1-step RO scenario was approximately 20% lower in costs than the Ultrafiltration (UF) – RO scenario. Air/water cleaning is effective to control clogging, while lowering flux values results in less membrane fouling.




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).

IMG20170307165729 (1)


(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!