Ics 2000

The prepared composite nanofiber membranes were characterized before and after fluoride adsorption experiments with field emission scanning electron microscopy (FE-SEM, FEI Philips XL 30) and X-ray diffraction (XRD, D8-Advance, Bruker, Billerica, MA, USA) at 12 kV in the range of 2θ from 3° to 30°. An ATR-FTIR spectrophotometer was utilized to obtain FTIR spectral data of the PVDF nanofiber, UiO-66, and UiO-66-NH₂ in addition to composite nanofiber membranes before and after adsorption. N₂ physisorption measurements at 77 K were used to determine the Brunauer–Emmett–Teller (BET) surface area of each sample. The spectra were obtained in the range of 4000–400 cm⁻¹. Fluoride detection was analyzed using an ion chromatography system from Thermo Fisher Scientific GmbH Germany (ICS 2000).

Metabolites were extracted from approximately 10¹⁰ cells using methods described in Kido Soule, Longnecker, Johnson, and Kujawinski (2015). Metabolites were identified by running a triple quadrupole mass spectrometer using positive (“pos”) and negative (“neg”) ion‐switching in selected reaction monitoring mode. The heatmap in Figure 1 was calculated using R with Ward clustering and Euclidean distance (Warnes et al., 2014, 2016). Concentrations of each metabolite are given as log₁₀ attomol per cell. For Pearson's correlation of metabolites to chloride concentration, samples were 1,000‐fold diluted prior to the measurement of sodium chloride on an ion chromatograph (ICS‐2000, DIONEX) using a DIONEX ASRS 300 4‐mm P/N 064554 column (Figure 2).

The detection methods used in study, including MLSS, MLVSS, TS, VS, sludge volume index (SVI), TCOD, SCOD, gaseous CH₄, CO₂, and H₂, total Fe, and specific resistance to filtration (SRF), have been elaborated in Supplementary Table 5. Liquid samples were taken using a syringe and filtered through disposable Millipore filter units (0.22 μm, Millipore, Millex GP) for the analyses of ammonium, nitrite, nitrate, phosphate and inorganic sulfur species (i.e. sulfide, sulfate, silfite and thiosulfate). Ammonium, nitrite, nitrate, and phosphate were analysed using a flow injection analyzer (Lachat Instrument, Milwaukee, Wisconsin), and the sulfur species were measured by Ion Chromatography with an ultraviolet (UV) and conductivity detector (Dionex ICS-2000)⁴² . Particle size was measured using dynamic light scattering (Zetasizer Nano ZS, Malvern Instruments). SRF, a common index of sludge dewaterability, was analyzed by using a multi-couple measuring device, as described in literature^{43 (link)}. The XRD patterns were generated using an X-ray diffractometer (Bruker D8). Prior to XRD measurement, the Fe-containing slurry was dried under vacuum conditions (−50°C, 0.1 mbar), and then ground into powder under anaerobic condition.

Samples of microbial mat deposits (250 g), sediment (250 g) and water (5L) were collected from Khirganga hot water spring (31°59′34″ N, 77°30′35″ E) in February 2017. Sampling was performed in two replicates for each habitat from two closely located primary thermal outlets (31°99′18″ N, 77°50′96″ E) and secondary outlets (31°99′19″ N, 77°50′96″ E). The surface temperature and pH of each habitat were recorded on site.
First, microbial mats and sediment were digested in pure nitric acid and water samples were filtrated to 0.1 μm prior to chemical analysis. All samples were subjected to physicochemical analysis for major elements. Concentrations of major cations (Na⁺, K⁺, Mg²⁺, and Ca²⁺) and anions (SO₄^2– and Cl^–) were analyzed by ionic chromatography (Dionex ICS-2000, Sunnyvale, CA) using the columns CS16A for measuring cations and AS17 for anions. An elemental analysis of minor and trace elements through inductively coupled plasma mass spectrometry (ICP-MS) Agilent ICP-MS 7,900 with ultra-high matrix introduction (UHMI). The samples of sediments and microbial mats were desiccated overnight followed by ethanolic dehydration and microstructure was studied using a scanning electron microscope at the Center for Chemical Microscopy (ProVIS). Images were captured using a high efficiency detector.

The concentrations of Pb, Cu, Cd, As, Hg, Cr⁶⁺, and Cl in the eluted solution of the original sample and in the treated samples were investigated in regard to the recycling possibility of the incineration ash. The concentrations of Pb, Cu, Cd, and As were measured via ICP–OES analysis. The concentrations of Hg and Cr⁶⁺ were measured using a UV–visible light spectroscopy system. The concentration of Cl was also investigated even though it is not a heavy metal, because the Cl concentration must be controlled as per the waste management laws of Korea. The concentration of Cl was calculated using ion chromatography (ICS-2000, Dionex, USA). In addition, to assess the change in the composition of the incineration ash sample before and after heavy metal removal, measurements were performed using an X-ray fluorescence spectrometer (XRF, EPSILON 4, PANalytical, NLD). Before the XRF analysis, the incineration ash samples were calcined at 700 °C to remove organic matter and achieve thermal stability.