Aqf 2100h

Total
fluorine (TF) analysis was carried out by CIC using an AQF-2100H combustion
unit (Mitsubishi, Japan) which was coupled to a Dionex ICS-2100 Integrion
IC (Thermo Scientific, U.S.) described in more detail by Schultes
et al.^{31 (link)} Subsampling for TF analysis involved
collection of small fabric pieces (∼0.5 mg) before and after
weathering (n = 4 samples of each textile), washing
(n = 4 samples of each textile), and abrasion (n = 4 samples of each textile). Since the fabrics were treated
in a noncontinuous batch process, some inter- and intratextile variability
in the DWR finish was expected. For each textile, a stencil was used
to cut out pieces to match the sampling location of exposed and unexposed
fabrics (A = 2 cm²; SI Figure S4). In addition, the homogeneity of fluorine content
on one fabric (C₈F₁₇–SFP coated) was
assessed via TF determination on random samples from different locations
(n = 9) on the same fabric (SI Figure S13). Further details of the TF analysis are provided
in S1.1 of the SI.

All
C-IC measurements were carried out using an ASC-240S autosampler and
an AQF-2100H combustion oven (Mitsubishi Chemical Analytech, Yamato-shi,
Japan). For absorption, a GA-210 absorption unit (Mitsubishi Chemical
Analytech) was used. Furthermore, an 881 Compact IC pro (Metrohm,
Filderstadt, Germany) with a conductivity detector was used for the
detection of chloride. A scheme of the whole setup is shown in the
Supporting Information (Figure S1). Table 1 comprises the detailed
experimental setup and parameters used for each measurement.
For all measurements, 20 mg of each silica gel obtained
from THF
extracts was weighed onto ceramic boats and were combusted at about
1000 °C for 18 min. The absorption solution consists of 300 mg/L
H₂O₂ (30% solution, Sigma-Aldrich, Schnelldorf,
Germany) in 10 mL of MilliQ water. As an internal standard, 5 mg/L
phosphate (1000 mg/L phosphate solution, Merck) was added.

The heating value of the food waste-based biochar was measured using a bomb calorimeter (6400 Automatic Isoperibol Calorimeter, Parr, Moline, IL, USA). For chlorine measurement, an ion chromatograph (AQF-2100H, Mitsubishi Chemical Analytech Co., Ltd., Kanagawa, Japan) was used. Proximate analysis was conducted according to the American Society for Testing and Materials D7582 experimental standard. For ultimate analysis, 2400 series II CHNS/O (Perkin Elmer, Boston, MA, USA) was used. The heavy metals in bio-SRF were analyzed using a mercury analyzer (M7600, Teledyne, Thousand Oaks, CA, USA), and an inductively coupled plasma-optical emission spectrometer (Agilent 720, Agilent, Santa Clara, CA, USA) was used to analyze ionic components. To analyze saltwater quality, biochemical oxygen demand (BOD), suspended solids (SS), total nitrogen (TN), and total phosphorus (TP) were analyzed using a standard method [62 ]. Total organic carbon (TOC) was analyzed using a TOC-L analyzer (Shimadzu, Kyoto, Japan). Chloride, sulfate, phosphate, nitrate, nitrite, and bromide ions were analyzed using an ion chromatograph (ICS-1100, Thermo Fisher Scientific, Waltham, MA, USA). The remaining volatile organic compounds (VOCs) were analyzed using a high-sensitivity (HS)–gas chromatography/mass spectrometer (QP2020NX, Shimadzu, Kyoto, Japan).