Ammonium molybdate

Ammonium molybdate ((NH₄)₆Mo₇O₂₄·4H₂O), thiourea (CH₄N₂S), ethanol (C₂H₆O), formaldehyde (CH₂O), hydrogen peroxide (H₂O₂) and ammonia monohydrate (NH₃·H₂O, 25–28%) were used as the analytical reagents and came from Sinopharm Chemical Reagent Co. The chitin textile fiber was purchased from Qingdao Yunzhou Technology Co., Qingdao, China.

Polymeric ferric sulfate, ammonium molybdate, silver sulfate, ferric nitrate, cerium nitrate, cobalt nitrate, potassium sodium tartrate, and ascorbic acid were all of analytical grade and were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). Mercury sulphate and potassium antimony tartrate were all of analytical grade and were purchased from Shanghai McLean Biochemical Co., Ltd. (Shanghai, China). The fly ash was taken from a coal chemical enterprise in Jiangsu. Cationic polyacrylamide (CPAM) was purchased from Jiangyin Huadong Water Treatment Co., Ltd. (Wuxi, China). The actual sludge water sample was taken from a sewage treatment plant in Jiangsu, and the original sludge quality is shown in Table 1.

Myriophyllum verticillatum (MV) was collected from Yanghu Wetland Park, Changsha, China, and after collection, it was washed several times with deionized water, dried naturally in the sun, and then dried in an oven at 60 °C for 24 h. The dried Myriophyllum verticillatum was then made into powder using a pulverizer and passed through a 70-mesh sieve. Triphenyl phosphate (TPhP) and sodium periodate (PI) were purchased from Shanghai McLean Biochemical Co. Manganese acetate, potassium permanganate, magnesium chloride, potassium dihydrogen phosphate, potassium persulfate, ascorbic acid, ammonium molybdate, and potassium antimony tartrate were purchased from Shanghai Sinopharm Chemical Reagent Co. Methanol, hydrochloric acid and sodium hydroxide were purchased from Tianjin Hengxing Chemical Reagent Manufacturing Co. HPLC-grade acetonitrile was purchased from Shanghai Aladdin Biochemical Technology Co. All chemicals were analytically pure, and ultrapure water (≥18.25 MΩ·cm) was prepared using an ultrapure water machine at the College of Environmental Science and Engineering, Central South University of Forestry Science and Technology.

Ammonium molybdate ((NH₄)₆Mo₇O₂₄·4H₂O) and thiourea (CH₄N₂S) were analytical reagents, purchased from Sinopharm Chemical Reagent Co., Ltd. The wool came from sheep in Bole City, Xinjiang Uygur Autonomous Region, China.

Iron chloride hexahydrate, poly(ethylene glycol), ethylene glycol were purchased from Aladdin Biochemical Technology Co., Ltd. (Shanghai, China); Sodium acetate (AR, ≥99%), ascorbic acid (AR, ≥99.7%), potassium dihydrogen phosphate (KH₂PO₄, AR, ≥99%), potassium antimony tartrate (AR, ≥99%), ammonium molybdate (AR, ≥99%), sulfate triacetyloxysilyl acetate (AR, ≥99%), lanthanum nitrate hexahydrate (AR, ≥99%) and ethanol were obtained from Sinopharm Chemical Reagent Co., Ltd. (Beijing, China).
Accurately, a certain mass of KH₂PO₄ was dissolved with water as phosphate stock solution, and the concentration was 1000 mgP/L. The adsorbed solution was prepared by diluting the stock solution with distilled water.