The Goliath Tigerfish, Hydrocynus goliath, is a ferocious predatory fish native to the Congo River Basin in Africa. It can grow up to 1.5 meters long and has be known to prey on small crocodiles and tearing large catfish into pieces! It occasionally attacks human since it is able to sense low frequency vibration in the water. It prefers to hunt in fast flowing water where smaller fish struggle to swim. Its massive teeth perfectly slide into distinct patches along its jaw. The Goliath Tigerfish is very rarely kept in any sort of aquarium although I did manage to spot a few at the Singapore River Safari the other day! See video below 🙂
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.
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:
- 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.
- 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.
- 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).
(Reverse osmosis membranes)
The blood parrot is an interesting fish with a round balloon-shaped body and a small mouth. Since it’s a hybrid developed by humans it does not occur in the wild. They come in many colours, but the most striking ones are those with yellow or red colour. The blood parrot is very popular aquarium fish. It is a hardy fish and is therefore easy for the beginner They are, however, messy eaters and will only consume part of the food that is given. A powerful filter and good cleaning of the substrate is necessary when keeping these fish. Originating from cichlid parents, one would expect these fish to be aggressive. However, this is far from the case and these fish can easily be housed with similar sized fish such as Angelfish, Corydoras, Silver Dollars and many catfish species.They are called parrotfish because their nose looks like the beak of a parrot 🙂