Potassium chloride (kcl)

AgNO₃, KCl, NaCl, MgCl₂, CoCl₂·6H₂O, NiCl₂, BaCl₂, CdCl₂, Zn (CH₃COO)₂, FeCl₂, MnCl₂·4H₂O, Pb (NO₃)₂, CaCl₂, CuSO₄, FeCl₃, AlCl₃, and CrCl₃·4H₂O were purchased from Energy Chemical Reagent Co., Ltd. (Shanghai, China). Sodium hydroxide (NaOH 96%) and hydrochloric acid (HCl 36–38%) were purchased from Kelong Chemical Co., Ltd. (Chengdu, China). o-phenylenediamine (o-PD) (98%), tertbutyl hydroperoxide (TBHP) (70%), and 3-chloroperbenzoic acid (85%) were obtained from Anhui Zesheng Technology Co., Ltd. (Anqing, China). The deionized (DI) water used in all experiments was produced using a Master Touch-S laboratory ultrapure water machine (Master Touch, Shanghai, China). Mineral water was taken from the laboratory at the Chenggong Campus of Yunnan University; lake water was taken from Ze Lake at the Chenggong Campus of Yunnan University (Kunming, China) and larger particles in the lake water were filtered out with a suction filter funnel before testing. Fetal bovine serum was purchased from Life Technologies (Grand Island, NY, USA) and diluted 100 times with DI water before testing. All the reagents were used as received, without further purification, unless otherwise noted.

KCl, NaCl, AgNO₃, CuSO₄, CaCl₂, MgCl₂, CoCl₂·6H₂O, NiCl₂, Zn(CH₃COO)₂, BaCl₂, CdCl₂, FeCl₂, Pb(NO₃)₂, FeCl₃, AlCl₃, MnCl₂·4H₂O and CrCl₃·6H₂O were purchased from Energy Chemical Reagent Co., Ltd. (Shanghai, China). Citric acid and anhydrous ferric chloride (FeCl₃) were obtained from Sahn Chemical Technology Co., Ltd. (Shanghai, China). Ethylene diamine was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. (Shanghai, China). The deionized water used in all experiments was made from a Master Touch-S laboratory ultrapure water machine (Master Touch, Shanghai, China). Lake water was taken from the Ze Lake at the Chenggong Campus of Yunnan University, Kunming, Yunnan, China. All the reagents were used as received without further purification, unless otherwise noted.

Birch wood (Betula alnoides) was harvested in Yunnan Province, southwest of China, which consisted of cellulose (38.6%), hemicellulose (22.5%), and lignin (20.1%). The dried birch was grounded to obtain 40–60 mesh wood particles, and the birch powder was extracted with toluene–ethanol (2:1, v/v) for 6 h to remove extractives. The dewaxed birch powder was dried at 60°C. Pd/C catalyst, AlCl₃, CeH₁₂N₃O₁₅, CaCl₂, FeCl₂·4H₂O, CoCl₂·6H₂O, FeCl₃·6H₂O, CuCl₂·2H₂O, KCl, MgCl₂, and ZnCl₂ were purchased from Energy Chemical (China).