Produced Water

NCIMB undertakes whole effluent assessment as part of a risk based approach to produced water management, supplies whole effluent assessment kits and offers a comprehensive package of chemical analysis.

MARA and LumiMARA for whole effluent testing

NICMB ‘s MARA and LumiMARA assays are used for whole effluent toxicity testing as part of a risk based approach to produced water management.   We offer a MARA and LumiMARA testing service at our Aberdeen laboratories, and also supply test kits.

OSPAR requires full implementation of a risk based approach to testing of produced water discharges from offshore installations by 31 December 2018, and NCIMB’s MARA and LumiMARA bioassays have been recommended by the UK’s Department of Energy and Climate Change (DECC), as part of their preferred approach to achieving this.

OSPAR is the organisation that manages international cooperation on the protection of the marine environment of the northeast Atlantic.

Trialled with samples from 15 offshore facilities

MARA and LumiMARA have been successfully trialled with produced water samples from 15 offshore facilities in the North Sea.  Samples included a mixture of oil and gas producers as well as early and late stages of production and high and low water cuts.

Quick, simple and cost effective

Using MARA and LumiMARA as an alternative to toxicity testing with a single species of bacteria is a very quick, simple and cost effective means of increasing the breadth and genetic diversity of toxicity testing, and may give more robust results. Test results have been found to be highly reproducible.

Our work with oilfield clients has illustrated additional benefits of using MARA to manage effluents.  For example, MARA and LumiMARA can be used to track changes in the toxicity profile of produced water following changes in additives such as corrosion inhibitors. We have also undertaken work to evaluate the potential of using MARA and LumiMARA to assess biocides efficacy.

MARA and LumiMARA testing procedure

The MARA test includes ten species of bacteria and one yeast, freeze dried in a micro-titre plate.  During testing the microorganisms are exposed to a concentration gradient of the test sample and incubated for 18 hours along with growth media and redox dye.  Growth of the microorganisms is then measured by assessing reduction of the dye through the use of a scanned image or plate reader and NCIMB’s MARA analysis software.

LumiMARA uses 11 species of naturally occurring bioluminescent bacteria.  When these bacteria are exposed to toxins, their luminescence is reduced and this can be used as a rapid and direct measure of toxicity. The bacteria are exposed to a concentration gradient of test sample and incubated for 15 minutes before the plate is read using a luminometer.

Plate readings from MARA and LumiMARA are used to calculate the microbial toxic concentration (MTC). MTC is a measure of inhibition equivalent to an EC50 value.  It is used for MARA and LumiMARA because it has a number of benefits including elimination of interpolation errors of classic EC50 determination.

Risk based approach to produced water management

All substances present in produced water will contribute to the total environmental risk, and implementation of a risk based approach requires measurement of known substances to be combined with whole effluent toxicity testing, in order to assess the impact of unknown substances and the combined effects of all components.  While companies operating in the UKCS have been undertaking chemical analysis as part of the biannual testing program, whole effluent toxicity testing is a new requirement.

Chemical analyses of produced water

We can undertake a range of chemical analyses at our laboratories in Aberdeen including:

  • Total hydrocarbon content
  • Chemical oxygen demand (COD)
  • Biological oxygen demand (BOD)
  • Mass spectrometry for metal analysis
  • pH
  • Sulphide/sulphate
  • Chloride/chlorine
  • Dissolved oxygen
  • Total suspended solids

We can also source and manage additional services where required in order to deliver comprehensive, bespoke, one-stop-shop waste and effluent testing package.

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