Mechanical step-type screen for the Kwun Tong Preliminary Treatment Works

Recently, Hydria Water has received more interest than usual from Asia, and currently has several parallel projects and inquiries ongoing.

– We are responding to a large number of inquiries from Asia at the moment. It is a very important part of the world for us and challenging as the large population makes for extremely large flows to handle. This requires us to design and build large machines with the right capacity, Rikard Karlsson at Hydria Water says.

The Kwun Tong Preliminary Treatment Works is one of the larger projects and is currently undergoing an extensive upgrade. For Hydria Water this means that the order will be fulfilled in three deliveries, the last of which will be completed in 2020, including a total of six mechanical step-type screens.

– The channels are four metres deep, and we are building machines with a discharge height of 5.5 metres.

Hydria Water purifies Hong Kong’s harbour

The Stonecutters Island Sewage Treatment Works in Hong Kong is a much-discussed project that has attracted a great deal of excitement, and to which Hydria Water delivered Mellegård & Naij’s products for several years. Soon, the last shipment to the sewage treatment works will leave our premises in Skövde, Sweden.

The Stonecutters Island Sewage Treatment Works is one of the world’s largest, treating roughly 2.5 million cubic metres of water every day from roughly 5.7 million people. This, together with the Changi Water Reclamation Plant in Singapore, is some of the largest project Hydria Water has ever undertaken.– It means a great deal to us to be contributing to such a large and amazing project that everyone in the industry is talking about. Our machines have been installed throughout the inlet and in the subsequent screenings handling process, and we will soon complete our last delivery, Rikard Karlsson at Hydria Water says.

– We have delivered eight Cross Screen XS mechanical-step type screens and eight conveyors. As the sewage treatment works is intended to handle large flows the channels are three metres deep, which meant that we had to build a mechanical step-type screen with a discharge height of 4.5 metres – which is among the highest we have ever delivered. The dimensions of the conveyors were between 7.5 and 15 metres, Rikard explains.

Over the course of the project, documentation and photography during manufacturing have been very important. This is particularly true prior to shipping, which takes 45 days from harbour to harbour.

– We sent a first test shipment. The client was satisfied with our products, considered them to be of high quality and wanted more of our machines, which of course felt very good. We have visited the site several times, among other times during the test run, when the flow was tripled so as to really test our machines!

The Stonecutters Island Sewage Treatment Works has undergone upgrades and alterations in several steps so as to achieve a cleaner environment in Victoria Harbour.

Step 1
During the first step, 23 kilometres of tunnels were dug underground in order to connect the seven water reclamation plants of Kowloon, Tsing Yi, Kwai Chung, Tseung Kwan O, and eastern Hong Kong Island to the Stonecutters Island Sewage Treatment Works, with the goal of purifying 75% of the wastewater in the harbour area on Stonecutters Island.

Step 2
During Step 2, eight water reclamation plants from northern to southwestern Hong Kong Island were connected, via 21 kilometres of underwater tunnels beneath the harbour basin, to Stonecutters Island Sewage Treatment Works, which at the same time was expanded and upgraded to handle the increased flow. Since of the completion of this step, 100% of the wastewater from the area around the harbour has been treated at the Stonecutters Island Sewage Treatment Works.

Large order from Cheung Sha Wan Wholesale Food Market

Cheung Sha Wan is a large food market in central Hong Kong to which Hydria Water is to deliver four Centerscreen CG and two Multiscreen Rake MR, which are to be used to treat raw water for tanks containing live fish. The machines are eight metres high and, due to the low ceiling height and constraints of the indoor space, will have to be assembled on-site and shipped from Sweden in parts.

– Shipping our products in parts forces us to think innovatively and in new ways in relation to a simple assembly, but at the same time this method saves a great deal of shipping space and we are able to ship the machines in one container instead of three. We will be on site to perform supervision during the assembly, and a delegation will also visit us in Sweden to learn more about the assembly process and the machines, Marko Kunerus Sales Manager at Hydria Water says.

Hydria Water purifies snow removed from the streets of Oslo

Due to stricter environmental requirements, Oslo no longer has the option to simply dump the snow removed from the city’s streets in the fjord, as has been done in the past. The Terje snow-melting system is a climate-smart pilot project that NCC has developed on a commission by the City of Oslo, and purifies snow using Hydria Water’s screens.

Terje weighs 500 tonnes, is 50 metres long and 26.5 metres wide, and operates at a depth of 3.5 metres below the surface of the quay near the Akershus Fortress in Oslo, where it is docked from mid-December to March. During the high season, snow is dumped into Terje’s intake grills on the deck of the barge by up to 20 fully loaded lorries per hour, then purified in several steps. Sea water is used to melt the snow. Up to 1000 cubic metres of water is collected from a depth of 24 metres, where the water temperature is typically between 4 and 10°C in the winter. At a sea water temperature of 9°C, it is possible to melt roughly 1000 cubic metres of snow per hour; if it drops to 4°C, the rate of melting is approximately 500 cubic metres per hour.

The efficiency of the purification process is 70% on average, and over 90% of the heavy metals in the snow are removed. The first step is a sedimentation process, in which stones and gravel are screened out when the snow is mixed with sea water and run through Hydria Water’s screens. The water is then transported through purification channels equipped with micro filters and lamella clarifiers. Over a tonne of oil per season is also screened out before the purified water is eventually released back into the fjord.


Foto: Odd Richard Valmot/NCC

Improved sludge removal using plastic chain scrapers at Tekniska Verken

The tanks are 40 meters long and 5 meters wide.

Tekniska Verken’s Nykvarnsverket wastewater treatment plant in Linköping was built in 1952, and since then has been rebuilt and expanded in various phases. In 2017 a new purification step that removes drug residues from wastewater using ozone was introduced, and Nykvarnsverket thus became Sweden’s largest full-scale facility for the removal of drug residues from wastewater.

Yet another upgrade of the facility is currently ongoing, and involves replacing the plant’s with new plastic chain & flight scrapers made by VA Teknik Sweden.

– Sludge removal will be more efficient and the machines will require significantly less maintenance, Hansi Gerhardsson at Hydria Water says.

– We have just delivered and installed the first four of a total of thirteen chain & flight scrapers using our own installation technicians.

The remaining nine chain & flight scrapers will be delivered over the course of the next year, and the total order value amounts to roughly four million SEK.


New Factory in Skövde

Mellegård & Naij produces premium products to water and waste water treatment plants all around the world. The manufacturing located in Skövde has decades of experience of manufacturing market leading equipment.

The demand has gradually increased, by the support from Hydria Water we are proud to announce that Hydria Group has reserved 17 000 m2 land in the newly developed industrial area of Norra Ryd in Skövde. The plan is to build a new factory for screens and screenings handling equipment of approximately 3000m2 which is more than double the size of today.

– It’s a fantastic feeling to get the trust to build a new facility with better working environment and more space. A top modern production facility provides us with opportunities to fully explore and develop the potential and know-how of Mellegård & Naij to become world leading manufacturer, says Martin Jingnäs CEO at Hydria Water. The aim is to have the new facility available in 2020 to further secure and even increase the number of employees in Skövde.

Growing demand for water treatment in UAE.

DUBAI, UAE - NOVEMBER 7: Dubai Marina. UAE. November 7, 2013. Dubai was the fastest developing city in the world between 2002 and 2008.

DUBAI, UAE – NOVEMBER 7: Dubai Marina. UAE. November 7, 2013. Dubai was the fastest developing city in the world between 2002 and 2008.

The annual demand for water increases in UAE and is currently estimated to 4,2 million kubicmeters. With increased population comes higher demands for water and waste water treatment. Currently there are several projects in execution phase, Hydria Water in close cooperation with Enexio Water Technologies Gmbh has supplied a vast number of Non metallic Chain & Flight scrapers and scum skimmers for primary clarifiers at Sharjah WWTP to enhance the performance and the growing demand.

Newly developed machinery to Mexico


Hydria Water has recently delivered several products from the portfolio to a returning client in Mexico. Previously there was plastic chain & flight scrapers with scum pipes and a stepscreen of Cross Screen XS type for the inlet screening. The latest order included a Disc Press QS from our Mellegard & Naij portfolio, the machine is a recently developed machine for sludge dewatering. The Disc Press QS is a machine based on the screw press principle whereas the sludge is transported inside stainless rings which inert is with a screw transporting the sludge through the set of inclined rings and pressed against a counter pressure plate to achieve as dry sludge as possible. The reject water is drained through the slots between the rings and taken for further treatment..

Hydria Water to upgrade the Al Aweer WWTP in Dubai


The Al Aweer WWTP is located some 30 km from Dubai and is currently under review and refurbishment plans to increase its capacity to 65 000 metercubes per day. Among others there is an upgrade made of the trickling filter media from the old rockfills to modern plastic media fills and

state of the art rotating distributor arms from VA Teknik Swedens product line. Recently representatives from VA Teknik Sweden visited the plant for commissioning advise and training.