Effect of Sodium Ion Concentration on Hydrogen Production from Sucrose by Anaerobic Hydrogen-producing Granular Sludge

This work evaluated the effects of sodium ion concentration, ranging from 0 to 16000mg·L^-1（Na^＋）, on the conversion of sucrose to hydrogen by a high-activity anaerobic hydrogen-producing granular sludge. At the optimum sodium ion concentration [1000-2000mg·L^-1（Na^＋）] for hydrogen production at 37℃, the maximum sucrose degradation rate, the specific hydrogen production yield and the specific hydrogen production rate were 393.6-413.1mg·L^-1.h^-1, 28.04-28.97ml·g^-1, 7.52-7.83ml·g^-1.h^-1, respectively. The specific production yields of propionate, butyrate and valerate decreased with increasing sodium ion concentration, whereas the specific acetate production yield increased, meanwhile the specific production yields of ethanol and caproate were less than 55.3 and 12.6mg·g^-1, respectively. The hybrid fermentation composition gradually developed from acetate, propionate and butyrate to acetate with the increase in sodium ion concentration.

Effect of Sodium Ion Concentration on Hydrogen Production from Sucrose by Anaerobic Hydrogen-producing Granular Sludge

This work evaluated the effects of sodium ion concentration, ranging from 0 to 16000mg·L-1(Na+), on the conversion of sucrose to hydrogen by a high-activity anaerobic hydrogen-producing granular sludge. At the opti- mum sodium ion concentration [1000—2000mg·L-1(Na+)] for hydrogen production at 37℃, the maximum sucrose degradation rate, the specific hydrogen production yield and the specific hydrogen production rate were 393.6— 413.1mg·L-1·h-1, 28.04—28.97ml·g-1, 7.52—7.83ml·g-1·h-1, respectively. The specific production yields of propionate, butyrate and valerate decreased with increasing sodium ion concentration, whereas the specific acetate production yield increased, meanwhile the specific production yields of ethanol and caproate were less than 55.3 and 12.6mg·g-1, respectively. The hybrid fermentation composition gradually developed from acetate, propionate and butyrate to acetate with the increase in sodium ion concentration.

Molybdenum removal from copper ore concentrate by sodium hypochlorite leaching

The removal of molybdenum from a copper ore concentrate by sodium hypochlorite leaching was investigated. The results show that leaching time,liquid to solid ratio,leaching temperature,agitation speed,and sodium hypochlorite and sodium hydroxide concentrations all have a significant effect on the removal of molybdenum.The optimum process operating parameters were found to be：time,4 h;sodium hydroxide concentration,10%;sodium hypochlorite concentration,8%;liquid to solid ratio,10：1;temperature,50℃;and, agitation speed,500 r/min.Under these conditions the extraction of molybdenum is greater than 99,9%and the extraction of copper is less than 0.01%.A shrinking particle model could be used to describe the leaching process.The apparent activation energy of the dissolution reaction was found to be approximately 8.8 kJ/mol.

Individualized Isonatremic and Hyponatremic Dialysate Improves Blood Pressure in Patients with Intradialytic Hypertension: A Prospective Cross-Over Study with 24-h Ambulatory Blood Pressure Monitoring

Background. Intradialytic hypertension, a paradoxical rise in systolic blood pressure from pre- to postdialysis, is a poorly understood and difficult-to-treat phenomenon. We examined the effects of individually adjusted isonatremic and hyponatremic dialysate on intradialytic and interdialytic blood pressure in patients with intradialytic hypertension. Methods. We enrolled 11 patients with intradialytic hypertension in a prospective randomized cross-over study, with 4 treatment periods of different dialysate sodium concentrations. Period 1 (run-in) and 3 (wash-out) were standardized at 140 mEq/L;period 2 and 4 with iso- or hyponatremic sodium dialysate. Blood pressure was recorded each dialysis session, and 24-hour ambulatory blood pressure monitoring was performed at the end of each treatment period. Results. Isonatremic and hyponatremic dialysate were associated with significantly lower pre- and post-dialysis blood pressure as compared to baseline 140 mEq/L dialysate (predialysis 148.3 ± 24.7/67.7 ± 12.0 and 144.4 ± 16.5/68.8 ± 13.3 vs. 158.0 ± 18.3/75.6 ± 11.4 mmHg, resp p = 0.04 and 0.007 for systolic and p = 0.004 and 0.04 for diastolic blood pressure;postdialysis 154.2 ± 25.5/76.6 ± 14.1 and 142.5 ± 20.7/73.0 ± 12.9 vs. 159.1 ± 21.6/80.3 ± 12.1 mmHg, resp NS and p = 0.01 for systolic and NS and p = 0.04 for diastolic blood pressure). Postdialysis and 24 h systolic blood pressure tended to be lower with hyponatremic compared to isonatremic dialysate. Conclusion. Individually tailoring dialysate sodium concentration, based on the sodium set-point of each patient, resulted in a lower pre- and post-dialysis blood pressure in patients with intradialytic hypertension. 24 h blood pressure values tended to be lower as well with hyponatremic dialysate.

Catalytic synthesis of diethyl carbonate with supported Pd-Cu bimetallic nanoparticle catalysts:Cu(Ⅰ) as the active species

Cupric oxide （CuO） and copper-cuprous oxide （Cu-Cu2O） nanoparticles were prepared by a simple hydrothermal method for the synthesis of diethyi carbonate （DEC） from ethanol. During these syntheses, varying NaOH and glucose concentrations were applied to explore and pinpoint the active species. It was found that PdCl2/CuO and PdCI2/Cu-Cu2O both catalysts exhibited good thermal stability and morphology. The results of catalytic tests showed that the catalysts prepared with 5 mol/L NaOH show superior catalytic performances because of their lower extent of agglomeration. It is noteworthy that the PdC12/Cu-Cu2O catalysts were the most active, especially the PdCl2/Cu-Cu2O catalyst prepared with 10 mmol glucose and having a higher Cu2O concentration. In Pd（ll）-Cu（II） （PdCl2/CuO） catalysts, there is an induction period, during which Pd（II） is reduced to Pd（0）, that must occur prior to electron transfer between Pd and Cu, and this can slow the catalytic reaction. To further pinpoint the active species, PdCl2/Cu-Cu2O catalysts with different Cu2O contents were prepared by controlling the dosages of glucose. The maximum DEC yield obtained with these catalysts was 151.9 mg.g-1.h-1, corresponding to an ethanol conversion of 7.2% and 97.9% DEC selectivity on an ethanol basis. Therefore, it was concluded that Cu＋ was the active species in this catalytic system, possibly because a higher proportion of Cu＋ reduces the Pd2＋ concentration and limits the CO oxidation side reaction, thus increasing DEC selectivity. In addition, Cu＋ promotes electron transfer between Pd and Cu without an induction period, which could also promote the catalytic activity.

Isolation of a novel strain of Cyanobacterium sp.with good adaptation to extreme alkalinity and high polysaccharide yield

The use of high alkaline medium is a feasible way to provide carbon source and prevent biological contamination for the outdoor cultivation of alkaliphilic microalgae and cyanobacteria.A novel cyanobacterial strain was isolated from the open pond of a marine green alga(Picochlorum sp.SCSIO-45015,Sanya,Hainan)and identified as Cyanobacterium sp.SCSIO-45682.The effects of initial sodium bicarbonate(NaHCO_(3))concentrations on the growth and biochemical composition of Cyanobacterium sp.SCSIO-45682 were investigated.The results demonstrated that Cyanobacterium sp.SCSIO-45682 had good adaptation to 16.8-g/L NaHCO_(3)(the same concentration of NaHCO_(3) used in Zarrouk medium for Spirulina).Moreover,the yields of biomass,polysaccharide,chlorophyll a(chl a),and phycocyanin increased under high NaHCO_(3) concentrations.The maximum final biomass concentration of 2.5 g/L was observed at 8.4-g/L NaHCO_(3),while the highest intracellular total saccharide content of 49.2%of dry weight(DW)and exopolysaccharide(EPS)concentration of 93 mg/L were achieved at the NaHCO_(3) concentration of 16.8 g/L.The crude protein content declined under high NaHCO_(3) concentrations,which provide a possible explanation for the accumulation of polysaccharide.This study shows a good potential of alkaliphilic Cyanobacterium sp.SCSIO-45682 as a polysaccharide feedstock.