Toc vcsh

Aqueous samples were investigated for their pH through a digital pH meter (PHS-38W Microprocessor, Tsingtao Toky Instruments Co., Ltd., Qingdao, China). A UV/Vis. spectrophotometer (T80 + PG Instruments, Lutterworth, UK) was used to determine phenol concentration at the wavelength of 269 nm. An ultrasonic bath (Cleaner model U Tech Products, Inc., Schenectady, NY, USA) was calibrated as reported [29 ] and used for the cavitation and sono-adsorption processes experiments. COD was analyzed after sample digestion (through the COD digester model (TR320, Merck Spectroquant)). The TOC was determined by injecting a 20 mL sample into the TOC analyzer (Shimadzu, model TOC-V CSH) in the furnace at 680 °C. The surface morphology of the WGTLs was investigated by a scanning electron microscope (SEM) instrument (Model-JSM 5910, JEOL, Tokyo, Japan). The Fourier Transform Infrared Spectroscopy (FTIR) analysis was performed, and IR spectra were recorded using the Potassium bromide (KBr) pellet technique on a FTIR spectrometer (Model-Perkin Elmer Spectrum 10D, Waltham, MA, USA) with a spectrum range of 500–4000 cm⁻¹ using a Resolution of 0.5 cm⁻¹.

DIC and non-purgeable organic carbon (referred to as DOC) were estimated with a Shimadzu combustion carbon analyzer TOC-Vcsh with ASI-V auto sampler. DIC was determined by injection into 25% phosphoric acid at ambient temperature with a calibration range of 0.35 to 40 mg l⁻¹ as C and both sodium bicarbonate solid and sodium carbonate solid standards (Nacalia Tesque). DOC was determined after acidification with 2 N HCl (five minute sparging) to remove DIC. The sample was then injected into the furnace at 680 °C with calibration from 0.35 to 3.5 mg l⁻¹ and limit of quantification of 0.20 mg l⁻¹ as C and potassium hydrogen phthalate solid standard (Nacalia Tesque).
A Dionex ICS-2000 anion chromatograph with AS40 auto sampler was used to determine nitrate and chloride concentrations (Guard column: IonPac AG18 guard, 4 × 50 mm; analytical column: IonPac AS18, 4 × 250 mm; suppressor: RFIC ASRS, 300 4 mm, self-regenerating; suppressor current: 99 mA). A 25 min gradient method was used with 25 μl injection volumes and a 1 ml min⁻¹ flow rate at 30 °C. The gradient consisted of 22 mM KOH (7 min), increasing KOH (1 min), 40 mM KOH (12 min), followed by decreasing KOH back to 22 mM (5 min). Aanion standards (1,000 mg l⁻¹ ; Spex CertiPrep, Metuchen, NJ) were diluted for a calibration range from 0.60 to 120 p.p.m., and measurement error was 2.5% for Cl^– and 1.4% for NO₃⁻.

Some of the samples were kept before and after the filtration test in order to conduct rejection analysis. Rejection analysis was divided under several tests, which are rejection of oil, total organic carbon (TOC) and turbidity. They were measured using UV-VIS Spectrophotometer (Model: DR 5000 Spectrophotometer, Hach Company, Loveland, CO, USA), Hach-Lange kits for COD, TOC analyzer (Model: TOC-VCSH, Shimadzu, Kyoto, Japan), and turbidity meter (Model: 2100Q Portable Turbidimeter, Hach Company, Loveland, CO, USA), respectively.