Cacl2 2h2o

Pinewood biochar was prepared at Mississippi State University (Starkville, MS, USA) via auger pyrolysis reactor at 450 °C under an N₂ environment (99.99%) . Biochar was ground into powder form (size between 200 and 400 μm). Metal salts calcium chloride (CaCl₂.2H₂O, 99.5%), zinc chloride (ZnCl_2, 99%), and potassium phosphate monobasic (KH₂PO_4, 99%) were purchased from the VWR (Radnor, PA, USA) and were used as received. Potassium hydroxide (KOH, ≥85%), nitric acid (HNO_3, 70%), hydrogen peroxide (H₂O_2, 30%), potassium nitrate (KNO₃, 99%), potassium sulfate (K₂SO₄, 99%), and potassium chloride (KCl, 99.0%) chemicals were supplied from Sigma Aldrich (St. Louis, MO, USA) and also used as received. P-containing wastewater (WW) samples were collected from a local wastewater treatment plant (H.C. Morgan Water Pollution Control Facility, Auburn, Alabama, USA), and untreated wastewater was used for the adsorption study. The inductively coupled plasma optical emission spectrometry (ICP-OES) results show that WW contains metals such as B (0.89 mg/L), Ba (0.02 mg/L), Ca (23.50 mg/L), Fe (1.01 mg/L), Mg (10.07 mg/L), Mn (0.11 mg/L), Na (15.52 mg/L), S (4.13 mg/L), and Si (8.0 mg/L). Analysis of total carbon (TC) and total nitrogen (TN) showed that the WW had concentrations of 66.85 mg/L-TC and 19.75 mg/L-TN, respectively.

mucin-alginate beads were used for small intestinal simulations and prepared by dripping a 5×-boiled mucin-alginate solution [50 g L⁻¹ mucin (Carl Roth), 12 g L⁻¹ agar (VWR), 12 g L⁻¹ alginate (Carl Roth) and 2.22 ml L⁻¹ 10 M NaOH (Chem-Lab)] into crosslinking solution containing 7.6 g L⁻¹ CaCl₂.2H₂O (VWR). This approach was implemented as the small alginate beads allowed for sterile sampling of colonized beads and addition of fresh beads via a 50 ml-syringe with catheter tip (Novolab) connected to an inlet port. Sterility of such handlings was a prerequisite as one worked with a synthetic consortium in multiple ileal simulations. In contrast, for the colonic microbiota, the conventional approach using mucin-covered microcosms was used as previously described by Van den Abbeele et al. (2012) (link). A buffer comprising (g L⁻¹) K₂HPO₄ (8.8; Chem-Lab) and KH₂PO₄ (6.8; Chem-Lab) was used to rinse luminal content from mucosal samples. Half of the mucus-alginate beads and mucin-covered microcosms were replaced every 2 days.