RESUMO
To deal with problems such as the difficult treatment of low-concentration fluoride-containing water and water pollution caused by excessive fluoride (F-) discharge, aluminum and zirconium-modified biochar (AZBC) was prepared and its adsorption characteristics and adsorption mechanism for low-concentration fluoride in water were studied. The results showed that AZBC was a mesoporous biochar with uniform pore structure. It could rapidly adsorb F- from water and reach adsorption equilibrium within 20 min. When the initial ρ(F-) was 10 mg·L-1and the AZBC dosage was 30 g·L-1, the removal rate was 90.7%, and the effluent concentration was lower than 1 mg·L-1. The pHpzc of AZBC was 8.9, and the recommended pH in practical application was 3.2-8.9. The adsorption kinetics accorded with pseudo-second order kinetics, and the adsorption process accorded with the Langmuir model. The maximum adsorption capacities at 25, 35, and 45â were 8.91, 11.40, and 13.76 mg·g-1, respectively. Fluoride could be desorbed by 1 mol·L-1 NaOH. The adsorption capacity of AZBC decreased by approximately 15.9% after 5 cycles. The adsorption mechanisms of AZBC were the combination of electrostatic adsorption and ion exchange.Taking actual sewage as theexperimental object, when the AZBC dosage was 10 g·L-1, the ρ(F-) was reduced to below 1 mg·L-1.
RESUMO
OBJECTIVE: To explore the effect of electroacupuncture on the improvement of insulin resistance after knee joint replacement based on the combined spinal and epidural anesthesia and postoperative epidural analgesia. METHODS: Eighty patients with insulin resistance but normal blood glucose were randomly divided into a control group and an observation group, 40 cases in each group.Both groups of patients underwent combined spinal and epidural anesthesia and postoperative epidural analgesia for knee arthroplasty. On the basis of the treatment,electroacupuncture (EA) was applied during the operation and within 1 month after the operation in the observation group, and EA was used at Hegu (LI 4), Qihai (CV 6), Zhongwan (CV 12), Pishu (BL 20), Shenshu (BL 23), etc. once every other day. The control group was not treated with electroacupuncture. Fasting blood glucose and fasting insulin were recorded 30 min before surgery (T0), immediately (T1), 1 d (T2), 3 d (T3), 7 d (T4) and 1 month (T5) after surgery, and the insulin resistance (IR) index was calculated. RESULTS: Compared with those at T0 time point, the IR index of the control group at T1, T3, T4 and T5 time points and the observation group at T1, T4, T5 time points were lower (all P<0.05). Compared with the control group at the same time point, the IR index of the T1 and T5 time points in the observation group was significantly lower (both P<0.05), and it was lower than the insulin resistance standard. CONCLUSION: Combined spinal and epidural anesthesia and postoperative epidural analgesia can improve short-term insulin resistance. Combined with EA, the improvement of insulin resistance is more obviously and longer.