In June 2013, the EPA proposed a new rule (40 CFR, part 423 click here) in an attempt to reduce the amount of toxic metals and other pollutants discharged to surface water from power plants. Previous regulations do not consider the additional burden of water discharge pollutants from air pollution control systems such as flue gas de-sulphurization (FGD), selective catalytic reduction (SCR) and flue gas mercury control (FGMC). The main pollutants of concern include metals (e.g mercury, arsenic and selenium), nitrogen and total dissolved solids (TDS). Toxic metal discharges have a huge impact on the environment as they bio-accumulate in wildlife and cause a wide array of human health issues. The new ruling would establish new and additional requirements for wastewaters associated with FGD wastewater, fly and bottom ash transportation water, flue gas mercury control water, combustion residual leachates from landfill and surface impoundments, metal cleaning wastes and gasification wastewater. Depending on the final options the best available technology (BAT) that is economically achievable will need to be applied to reduce pollutant discharges. This is particularly challenging for dissolved forms of As, Se and Hg as they are not removed by surface impoundments.

P S Analytical can help with these Monitoring and Analytical Requirements

PSA have a number of measurement and sampling solutions to confirm the efficiency of the wastewater treatment processes and for compliance monitoring. These are outlined in the Tables below:



 Online Hg Analyser UV-CV-AFS
 Online System with part-per-trillion - ng L-1 detection limits incorporating online UV  digestion.Suitable for filtered wastewater applications



Arsenic, Selenium, Antiomny, Tellurium & Bismuth

 Online As, Se and Sb Analyser UV-HG-AFS
 Online system with part-per-trillion - ng L-1 detection limits. Element specific analyser  based on UV digestion hydride generation – AFS. Suitable for filtered  wastewater applications





 Millennium Merlin CV-AFS
 Millennium Merlin 1631 CV-Amalgam-AFS

 Automated laboratory system with sub part-per-trillion - ng L-1 detection limits. Suitable for all  wastewater streams, leachates and solid samples



Arsenic, Selenium, Antiomny, Tellurium & Bismuth

 Millennium Excalibur HG-AFS
 Automated laboratory system with part-per-trillion - ng L-1 detection limits suitable for all  wastewater streams leachates and solid samples




Mercury, Arsenic, Selenium, Antiomny, Tellurium & Bismuth

 Modular Interface - Speciation and Online digestion Module
 Laboratory based system to interface with Millennium Systems. Consists  of integrated LC pump, injection valve and online digestion manifold  offering speciation for all elements



All the above systems are based on cold vapour/hydride generation with atomic fluorescence spectrometry (AFS). Alternative techniques such as ICP-MS with collisional cells are costly laboratory instruments with numerous limitations and comparatively poor method detection limits. Large sample dilutions are required to overcome the interference issues due to total dissolved solids found in wastewater samples. The AFS systems however provide detection limits in the part per trillion range with linearity over 7 orders of magnitude. Waste water samples are treated online using a UV photolysis system which provides a determination for total metal content. The system offers an online measurement solution to ensure that abatement systems are effectively achieving permitted levels. (EPA 200.8)