The filtered medium (0.2 μm; Whatman) was concentrated using Amicon Ultra-4 centrifugal concentration filter tubes (Millipore) with a 10 kDa MW (molecular mass) cut-off.
Based on the results of a model sensitivity analysis, several variables were determined to be important in the clogging phenomena observed in ISFs, including hydraulic loading rate, influent chemical oxygen demand (COD) concentration, filter dosing frequency, and time of operation.
To count bacterial abundance, duplicate 2 mL samples were fixed with 100 μl of formaldehyde (2 % final concentration), filtered onto 0.2 μm black polycarbonate filters (Whatman), then immediately stained with DAPI (100 μg mL−1) for 15 min at 4 °C in dark (AQSIQ 2007).
To determine the IL-23 concentration, filtered supernatants were diluted 1∶4 in diluent contained in the human IL-23 (p19/p40) ELISA kit (eBioscience), and assays were performed according to the manufacturer's specifications.
The chemistry model predicts filtered chemical species concentrations and filtered reaction rates in a turbulent flow.
PM2.5 mass concentration (by filter weighing), trace element concentrations (by X-ray fluorescence technique), and black carbon measurements (using the reflectance technique) were conducted at the NYU Nelson Institute of Environmental Medicine laboratory (Tuxedo, NY).
The concentrations of filter paper, corn steep liquor, cysteine hydrochloride and ferrous sulphate in the medium, which have been found to be optimal for ethanol production, were 45, 8.0, 0.25, and 0.01 g/l, respectively.
Thousand fold stock solutions of the respective exposure concentrations were filter sterilized (0.2 μm) and stored at 4°C.
Microarrays were washed manually with solutions containing decreasing concentrations of filter sterilized SSC 20× and SDS 10% (Sol.1: 1× SSC-0.2% SDS; Sol.2: 0.1× SSC-0.2% SDS; Sol.3: 0.1× SSC; Sol. 4: double deionized water).
