|
Click the headline below to read the Press Release
..
At the IWEX exhibition in Birmingham, 11th to 13th November, PPM
will officially launch the ProAm, an innovative and new ammonia
analyser.
The instrument has undergone extensive in-house and field testing.
A number of units have already been sold and installed at key customer
sites. Based on current feedback we anticipate that this instrument
is set to establish it’s self as the preferred instrument
for a number of the UK’s water companies. A number of units
installed within industry have also given un-paralleled operational
and measurement reliability.
Key advantages include:-
• Compact design using a proven technique
• No filtration typically required due to large tubing & pinch
valve technology
• Automatic cleaning as standard, improves reliability
• Simple user friendly operation
• Low detection limit (0.05ppm)
• Low capital and running costs
• Minimum maintenance requirements
The analyser comprises of an Ion Selective Electrode (ISE), reaction
vessel, peristaltic pump unit and microprocessor controlling electronics.
The sensor is a gas sensitive electrode used to report ammoniacal-nitrogen
concentration in liquids. A reagent is added to the sample and the
ammonium is converted to ammonia which diffuses through the electrode’s
membrane. The electrode potential changes logarithmically according
to the level of ammonia in the sample.
The standard instrument can be ranged from 0-1ppm to 0-500ppm as
required with special applications up to 1000ppm. Calibration takes
place at two points, low and high. The high calibration point is
equivalent to the upper point of the scale and the low is one decade
smaller. For example a range on 0-100ppm would have a calibration
standard of 10 and 100ppm. The calibration sequence is used to validate
measurement performance and alarm an unacceptable repose from the
electrode.
The detected concentration is displayed locally on the instrument’s
LCD and can also be connected to telemetry. In addition to the analogue
4-20mA output, there are two user programmable alarm set points
for ammonia high and high-high as well as two utility alarm relays.
These may be configured for the loss of sample/calibration/reagent/wash
solutions and poor probe sensitivity. A fourth relay can be assigned
for either no sample or an off-line alarm (to indicate when the
instrument is calibrating or cleaning). Other communication protocols
are also being developed.
The instrument is designed to run as an automatic analyser but manual
intervention may be initiated from the tactile keypad. The ProAm
is typically configured for continuous measurement but intermittent
analysis may also be programmed to further conserve reagents.
Should you wish to attend the IWEX exhibition then please contact
the PPM office to arrange for a complimentary ticket to be sent.
PROTOC on-line TOC analysers from Pollution and Process Monitoring
(PPM) Ltd have recently been installed at Stansted Airport.
As Britain's third largest airport, Stansted handles over five and
a half million passengers a year. By the year 2000, this will have
risen to an estimated seven million. The airport sees activity around
the clock - passenger flights by day and mostly cargo flights by
night - and presently offers parking for between sixty five and
eighty aircraft with plans to increase this facility further.
Obviously, the airport can't afford to stop when temperatures drop
below zero, so glycol is used plentifully to de-ice aircraft, runways,
taxi-ways and standing areas when the weather deteriorates.
However, the use of glycol can pose a problem for those responsible
for ensuring the quality of water the airport discharges. It is
washed away by rain or snow into the main drainage system - and
contaminates it.
'Prior to installing the PPM PROTOC units, the airport was only
monitoring the flow and temperature of the discharge explains Stansted's
Water Quality Manager Barry Carter. 'This only enabled us to make
general assumptions about the quality of storm water discharge.
For example, if we experienced poor flow, coupled with low ambient
temperature, it was assumed de-icing had taken place in the airport
and the run off was diverted for treatment.'
With increasingly strict EPA guidelines and discharge consents,
Stansted recognised that it needed a more thorough and accurate
monitoring and alarm system on site. Consultants Balfour Mausell
recommended the PROTOC on-line analyser from PPM Ltd and it was
one of several instruments evaluated for the site. After a six month
on-site test period, PROTOC was selected and four units purchased
to monitor critical areas around the site. All four were installed
in November 1997, providing Stansted with critical monitoring and
alarm facilities.
The airport has three catchment areas, taking storm water from a
comprehensive drainage system. The three areas are designated 'Urban',
'Runway' and 'Stands'. All three discharge in turn into a holding
area called 'Pond C'. A PROTOC unit is situated at the spilling
chamber from each catchment area, monitoring the TOC content of
the water.
 |
 |
Real time information is then back indicated
from the PROTOC units to the Airport Duty Engineer's Office
via a Faros radio linked telemetry system. High alarms are
set at 25ppm and, should high concentrations of Glycol or
other contaminants be present, an automatic divert comes into
effect. The storm water is diverted away into a storage pond
where it is aerated and then pumped away to the Thames Water
Utilities Plant at nearby Rye Meads for treatment. |
Uncontaminated storm water is allowed through to 'Pond C' where
rope mops and oil traps are used to tackle surface pollutants and
suspended solids.
From 'Pond C', the storm water runs through a water course to an
outlet on Pinchy Brook, which itself eventually feeds into the River
Stort. The flow from 'Pond C' is highly seasonal and can vary from
a low of 20 litres per second right up to 350 litres per second
in periods of high precipitation.
The fourth PPM PROTOC unit is located at the outlet into Pinchy
Brook and provides a real time fail-safe check that discharge consents
are being adhered to. Information from this unit is also sent back
via radio link telemetry to the Airport Duty Engineer's Office.
In addition to manufacturing and supplying the four PROTOC units,
PPM Ltd are also providing a weekly on-site service, maintenance
and consultation facility.
Stansted are now consistently meeting or improving their discharge
consent levels. In the near future, they plan to further refine
their PROTOC system by customising valve controls and infra-red
sensors.
Pollution & Process Monitoring Ltd
Bourne Enterprise Centre
Borough Green
Sevenoaks
Kent TN15 8DG
Tel: +44 (0) 1732 882044
Fax:+44 (0) 1732 780190
E-mail:  TOC@pollution-ppm.co.uk |
