Proposal to Test Carbobyk-9810 to Determine Sludge Sorption and Subsequent Receiving Stream Concentration

Proposal to Test Carbobyk-9810 to Determine Sludge Sorption and Subsequent Receiving Stream Concentration Proposal to Test Carbobyk-9810 to Determine Sludge Sorption, and Subsequent Receiving Stream Concentration ASU will conduct experiments using a 5% liquid dispersion of BYK MWCNT product. The dispersion matrix is water containing polymers and biocide agents. Dilutions from this liquid dispersion will be made into 1 mM NaHCO3. Experiments will start with an initial concentration of 0.13 mg MWCNT/L in solution. We have already conducted preliminary validation for two independent analytical methods that will be applied to quantify the MWCNT, which are suitable for different but overlapping concentration ranges: 1. 0.5 to > 50 mg/L using UV/VIS 2. ~ 0.001 to > 10 mg/L using spICP-MS on catalyst residual (Yttrium) in the MWCNT, which is analogous to published work on SWCNT (Reed et al., Environ. Sci: Processes & Impacts, 15:204, 2013). Task 1 Analytical Method Calibration Curves Descriptions of the analytical methods will be provided. Calibration curves for the two methods will be provided over the concentration range of interest. Statistical analysis of the MDL will be performed following EPA procedures. The detection methods, will have a detection level of at least 0.05 mg/L to demonstrate removal effectiveness during the biomass tests. Matrix interference (from biomass only) will be considered in reporting the calibration of MDL. Furthermore, ASU will demonstrate through dissolution tests using ultrapure water, dilute nitric acid, and dilute tetramethylammonium hydroxide, plus TEM with EDX analysis, that the yttrium is not dissolved out of the CNT. Task 2 Stability of MWCNT in liquid wastewater matrix. A sample of primary effluent from a local wastewater treatment plant (WWTP) will be collected, and filtered to remove particulates. BYK MWCNT will be spiked into the this filtered primary effluent, and a parallel container with 1 mM NaHCO3 in ultrapure water. Changes in Dynamic Light Scattering (DLS) of particles in solution during slow mixing will be monitored over 4 hours. Mixing will then be ceased and liquid phase (supernatant) concentration of MWCNT will be measured. The data will be summarized to