Enhancing the pollutant removal performance and biological mechanisms by adding ferrous ions into aquaculture wastewater in constructed wetland.

Aquaculture wastewater seriously threatens the human health. In this study, non-poisonous iron was added into constructed wetlands to purify aquaculture wastewater and the wastewater treatment performances of CWs were explored under the treatment conditions of different plant species and different dosages of ferrous ions. The optimal treatment conditions were experimentally determined as follows: 20 mg/L ferrous ions in CWs planted with Canna indica after 7-day operation, the removal efficiencies of TN, TP and COD were respectively 95 ±â€¯1.9%, 77 ±â€¯1.2% and 62 ±â€¯2%. The improvements in the pollutant removal performance depended on biological mechanisms of plants and microorganisms. The optimal dosage of iron ions could adjust enzyme activities and functional amino acids. Specific functional bacteria (Paracoccus detected based on nirK genetic information and Hydrogenophaga detected based on pufM genetic information) were cultured and domesticated by iron ions. The functional bacteria promoted nitrogen and phosphorus removals.

Ropivacaine used for brachial plexus block on children / 中国基层医药

Objective To study comparatively the clinical anaesthetic potency and adverse effects to children of 0.375% ropivacaine used for brachial plexus block in upper-limb paediatric surgery.Methods After undergoing basal anesthesia with ketamine,36 children scheduled for hand and forearm surgery were randomly allocated to receive brachial plexus block with 0.375% ropivacaine(group A) and to receive intravenous anesthesia with ketamine(group B).The effect of sensor block and motor block,the changes of vital sings,the occurrence of side effect(nausea and vomiting) and palinesthesia of children were observed.Results The patients in group A kept a steady vital signs,their blood pressure,cardiac and respiration rate were similar to the backgroud level before anesthesia,whereas in group B the blood pressure,cardiac and respiration rate of patients were increased and kept a rather higer level,fluctuated with the depth of anesthesia.Conclusion Ropivacaine used for brachial plexus block in upper-limb paediatric surgery is a simple,feasible,and safe method with anesthetized perfectly and less complication.