Treatment of phosphate-containing oily wastewater by coagulation and microfiltration.

The oily wastewater generated from pretreatment unit of electrocoating industry contains oils, phosphate, organic solvents, and surfactants. In order to improve the removal efficiencies of phosphate and oils, to mitigate the membrane fouling, coagulation for ceramic membrane microfiltration of oily wastewater was performed. The results of filtration tests show that the membrane fouling decreased and the permeate flux and quality increased with coagulation as pretreatment. At the coagulant Ca (OH)2 dosage of 900 mg/L, the removal efficiency of phosphate was increased from 46.4% without coagulation to 99.6%; the removal of COD and oils were 97.0% and 99.8%, respectively. And the permeate flux was about 70% greater than that when Ca(OH)2 was not used. The permeate obtained from coagulation and microfiltration can be reused as make-up water, and the recommended operation conditions for pilot and industrial application are transmembrane pressure of 0.10 MPa and cross-flow velocity of 5 m/s. The comparison results show that 0.2 microm ZrO2 microfilter with coagulation could be used to perform the filtration rather than conventional ultrafilter, with very substantial gain in flux and removal efficiency of phosphate.

[Effect of coagulation on the performance of microfiltration in treating phosphorus-containing wastewater].

Treatment of high-concentration phosphorus-containing wastewater produced from automobile painting-industry using microfiltration with and without coagulation pretreatment was studied. The results show that the membrane fouling decreased by reducing the extent of pore plugging and improving the shape of cake layer formed on membrane surface and the permeate flux increased with coagulation as pretreatment. In comparison with direct microfiltration (without coagulation), pretreatment with lime improves removal of phosphate from 11.0% to 99.7%. The permeate obtained from coagulation and microfiltration can meet the national discharge standard and be reused under very safe conditions. With the same cleaning method, the recovery of permeate flux is approximately 18% greater than that of without coagulation pretreatment, which may be due to the differences in the shape of deposited cake and the extent of irreversible fouling.

[Multicentral randomized controlled study on effects of acupuncture at Zusanli (ST 36) and Xuanzhong (GB 39) on cerebrovascular function in the patient of ischemic stroke].

OBJECTIVE: To explore effect of acupuncture at Zusanli (ST 36) and Xuanzhong (GB 39) on cerebrovascular function in the patient of ischemic stroke. METHODS: Three central, single blind, randomized controlled trial method was adopted, and 160 cases were randomly divided into an acupuncture group and a control group, 80 cases in each group. The two groups were treated by routine treatment for ischemic stroke with acupuncture at Zusanli (ST 36) and Xuanzhong (GB 39) added in the acupuncture group. Changes of TCD cerebrovascular blood flow indexes before and after treatment were evaluated. RESULTS: After treatment, TCD indexes significantly improved in the acupuncture group (P < 0.05, P < 0.01) with a significant difference as compared with that in the control group (P < 0.05). CONCLUSION: Acupuncture at Zusanli (ST 36) and Xuanzhong (GB 39) can significantly improve cerebral vasomotoricity, cerebral blood flow auto-regulative function, cerebral hemisphere collateral circulation comprehental function in the patient of ischemic stroke.