- Email: [email protected]
Nitrous oxide monitoring technology wins innovation award
New products
Filtration+Separation July/August 2006
Dow introduces membrane elements with extended pH limits
Nitrous oxide monitoring technology wins innovation award
Dow’s FILMTEC membrane elements are now able to withstand a wider pH range of 1-13 for membrane cleaning solutions, the company says.
Water Innovate, a UK-based developer of new water technologies has been awarded £40,000 to help extend the market potential of its N-Tox nitrous oxide monitoring technology.
The Filmtec elements, available from Dow subsidiary FilmTec Corp, can now be cleaned with the widest pH range in the industry, Dow says. Typical cleaning pH limits by other membrane manufacturers are reportedly in the range of 3.5-10, referring to limits of 2-12 as harsh cleanings, reports Dow. The extended pH range of these membranes can help increase the efficacy of foulant removal from the membranes, and lead to longer operating time between cleanings and longer membrane lifespan in Reverse Osmosis (RO) and NF90 systems. Fouling and scaling, due to the presence of organic and inorganic contaminants in RO feedwater, is a typical occurrence in water treatment systems. The higher pH limit of 13 improves the removal of biofouling and organic fouling from the
membranes, while the lower pH limit of 1 increases the efficiency of calcium carbonate removal. According to the company, the membrane is not oxidised as part of its membrane manufacturing process. “It is well known that oxidation of thin film composite membranes weakens the membrane structure resulting in a salt passage increase during its operating life,” says Jon Goodman, market manager (Americas) for Filmtec membranes. “Cleaning at aggressive pH further weakens oxidised membranes resulting in more accelerated membrane deterioration.” “The pH and temperature tolerance of membrane elements are important factors in both selecting a membrane suitable for reliable long-term operation, and in determining an appropriate cleaning regimen for membranes. Both are critical choices to ensure successful RO operation,” Goodman adds. www.dow.com
Bag type filter uses pressurised air for cleaning The European arm of water purification specialist Rosedale Products has developed a backwashing bag type fluid filter, which uses pressurised air for cleaning, and thus, the company says, reduces maintenance costs.
bag is positioned between internal and external support cylinders. These retain the bag against the filtering flow, which is from outside the bag inwards, and the backwashing air flow, which is passed through the bag from the inside to the outside.
The cleaning works by releasing pressurised air into the inside of the filter bag in the opposite direction to the normal filtering flow. Accumulated particulate contaminant on the surface of the bag is therefore dislodged and transported to a safe location.
The units can be cycled through many backwashes, before any further servicing is required, Rosedale says, and the filter bags, which are normally thrown away when full, can be re-used many times. However, the company comments, the actual number of cycles depends on several factors; felt media will have a shorter life than monofilament nylon; and contamination type and size also have an effect on bag life and the period between backwashes.
In a standard Rosedale bag filter the fluid flow is from inside the bag outwards, so that dirt accumulates on the inside of the bag; an external perforated support cylinder retains the bag against the flow. In a backwashing filter, however, the
www.rosedaleproducts.com
The Shell Springboard Awards judges, which selected the company’s technology, were looking for commercially viable business plans for innovative products and services, which would lead to greenhouse gas reductions. N-Tox technology allows wastewater plant operators to
detect nitrous oxide, a greenhouse gas with almost three hundred times the global warming potential of carbon dioxide. “Nitrous oxide is an important but often overlooked greenhouse gas,” said Tom Stephenson, technical director at Water Innovate. “Over 4% of its emissions arise from wastewater treatment, and these discharges are expected to increase significantly as tougher effluent nitrogen controls come into force.” www.waterinnovate.co.uk
Water Innovate delegates receive the Shell Springboard Award.
9
Filtration+Separation July/August 2006
Dow introduces membrane elements with extended pH limits
Nitrous oxide monitoring technology wins innovation award
Dow’s FILMTEC membrane elements are now able to withstand a wider pH range of 1-13 for membrane cleaning solutions, the company says.
Water Innovate, a UK-based developer of new water technologies has been awarded £40,000 to help extend the market potential of its N-Tox nitrous oxide monitoring technology.
The Filmtec elements, available from Dow subsidiary FilmTec Corp, can now be cleaned with the widest pH range in the industry, Dow says. Typical cleaning pH limits by other membrane manufacturers are reportedly in the range of 3.5-10, referring to limits of 2-12 as harsh cleanings, reports Dow. The extended pH range of these membranes can help increase the efficacy of foulant removal from the membranes, and lead to longer operating time between cleanings and longer membrane lifespan in Reverse Osmosis (RO) and NF90 systems. Fouling and scaling, due to the presence of organic and inorganic contaminants in RO feedwater, is a typical occurrence in water treatment systems. The higher pH limit of 13 improves the removal of biofouling and organic fouling from the
membranes, while the lower pH limit of 1 increases the efficiency of calcium carbonate removal. According to the company, the membrane is not oxidised as part of its membrane manufacturing process. “It is well known that oxidation of thin film composite membranes weakens the membrane structure resulting in a salt passage increase during its operating life,” says Jon Goodman, market manager (Americas) for Filmtec membranes. “Cleaning at aggressive pH further weakens oxidised membranes resulting in more accelerated membrane deterioration.” “The pH and temperature tolerance of membrane elements are important factors in both selecting a membrane suitable for reliable long-term operation, and in determining an appropriate cleaning regimen for membranes. Both are critical choices to ensure successful RO operation,” Goodman adds. www.dow.com
Bag type filter uses pressurised air for cleaning The European arm of water purification specialist Rosedale Products has developed a backwashing bag type fluid filter, which uses pressurised air for cleaning, and thus, the company says, reduces maintenance costs.
bag is positioned between internal and external support cylinders. These retain the bag against the filtering flow, which is from outside the bag inwards, and the backwashing air flow, which is passed through the bag from the inside to the outside.
The cleaning works by releasing pressurised air into the inside of the filter bag in the opposite direction to the normal filtering flow. Accumulated particulate contaminant on the surface of the bag is therefore dislodged and transported to a safe location.
The units can be cycled through many backwashes, before any further servicing is required, Rosedale says, and the filter bags, which are normally thrown away when full, can be re-used many times. However, the company comments, the actual number of cycles depends on several factors; felt media will have a shorter life than monofilament nylon; and contamination type and size also have an effect on bag life and the period between backwashes.
In a standard Rosedale bag filter the fluid flow is from inside the bag outwards, so that dirt accumulates on the inside of the bag; an external perforated support cylinder retains the bag against the flow. In a backwashing filter, however, the
www.rosedaleproducts.com
The Shell Springboard Awards judges, which selected the company’s technology, were looking for commercially viable business plans for innovative products and services, which would lead to greenhouse gas reductions. N-Tox technology allows wastewater plant operators to
detect nitrous oxide, a greenhouse gas with almost three hundred times the global warming potential of carbon dioxide. “Nitrous oxide is an important but often overlooked greenhouse gas,” said Tom Stephenson, technical director at Water Innovate. “Over 4% of its emissions arise from wastewater treatment, and these discharges are expected to increase significantly as tougher effluent nitrogen controls come into force.” www.waterinnovate.co.uk
Water Innovate delegates receive the Shell Springboard Award.
9