Anaerobic digestion of alkaline black liquor using an up-flow anaerobic sludge blanket reactor

The anaerobic digestion of alkaline black liquor from a cereal straw pulping mill was studied in batch (serum bottles) and continuous systems (up-flow anaerobic sludge blanket reactor—UASB). The batch digestion studies confirmed that lignin and related compounds (LRC) in the alkaline black liquor were the main inhibitory substances and could not be decomposed by anaerobic bacteria. At organic loading rates of 5–10 kg COD m^?3 day^?1, the UASB reactor achieved 50–60% COD removal efficiencies. Gas production was 2–3 dm³ per dm³ of alkaline black liquor. Two different sludge types were examined in the reactor: granular and cluster-like sludges. Sludge in a cluster, which involved many small granules and flocs, tended to form larger aggregates and possessed good settling ability.     

仿石瓷质砖包裹颗粒的制备新工艺

本文分析了当前流行的仿石瓷质砖包裹颗粒制造方法的弊端,并通过改进设备和采用新的工艺方法,研制出仿石效果更佳的产品,这样既提高了颗粒的包裹效率,又降低了生产成本。     

The comparative effect of a mixed urea,ammonium nitrate,ammonium sulphate granular formulation on the efficiency of N recovery by perennial ryegrass

The¹⁵N isotope was used to study the mode of action of individual nitrogen sources in a 30% urea:30% ammonium nitrate: 10% ammonium sulphate:30% filler (w/w) granular fertilizer for perennial ryegrass in a greenhouse pot experiment. The fertilizer consisted of two types of granules, one containing 80% urea and 20% filler and the second containing 48% ammonium nitrate (AN), 16% ammonium sulphate (AS) and 36% filler. In addition the effect of dolomite compared with silica as the filler was investigated on nitrogen recovery from the 30:30:10:30 formulation.Dolomite adversely affected the recovery of nitrate N from the system and evidence suggested that MgCO₃ was the active component. Granules containing dolomite resulted in a lower dry-matter yield than those containing silica, however the difference was not significant as nitrate contributed only 20% of the N in the formulation. AN gave the greatest DM yield and urea the lowest with AS being intermediate. The¹⁵N budget in shoots, roots and soil indicated that only 65% of the N from urea was recovered at the end of the experiment compared with 86% for AN and 91% for AS. The dry-matter yield of the 30:30:10:30 formulation using silica as the filler was intermediate between urea and AN; however, the apparent N recovery was significantly higher than expected from the sum of the individual components. The use of¹⁵N labelling indicated that using separate granules for ammonium N and urea the recovery of urea was improved by 11% in the triple N mixture when both AN and AS were present in the second granule compared to the recovery on its own. The enhanced recovery of urea appeared to be a function of AN and AS acting together as neither source in double combination with urea had any effect on urea N recovery.Urea enhanced the recovery of nitrate N by 10% but decreased the recovery of AS by 6% (in the 30:30:10:30 formulation) in comparison with the single sources on their own. The results indicate that interactions can occur between N sources even when they are physically separated by being in different granules.     

Alkali catalyzed liquefaction of corncob in supercritical ethanol–water

Corncob liquefaction in supercritical ethanol–water was performed with and without the addition of an alkali catalyst by direct addition or biomass impregnation in a 250-cm³ batch reactor. The effects of temperature, solvent and alkali addition on the biomass conversion level and oil yield were investigated to find the optimum condition. For non-catalytic liquefaction using a 1:1 (v/v) ethanol: water ratio, a maximum oil yield and conversion level of 49.0% and 93.4%, respectively, were obtained at 340 °C. For alkali catalytic liquefaction, the oil yield with KOH addition (57.5%) was higher than that from KOH-impregnated corncob liquefaction (43.3%). The oil from liquefaction with KOH addition had higher heating value (26.7–35.3 MJ kg⁻¹) than the corncob (19.1 MJ kg⁻¹). The dominant components of the obtained oil were found by GC/MS analysis to be aldehyde, ester, phenol derivatives and aromatic compounds.     

用玉米芯水解液发酵木糖醇的研究

对用玉米芯水解液发酵木糖醇进行了研究。结果表明玉米芯水解液中的葡萄糖和杂质成分对木糖醇发酵具有抑制作用。试验显示一些添加剂能明显减轻这种抑制作用。本试验用玉米芯水解液进行的木糖醇发酵中,木糖醇的转化率为理论值的74.9%。     

Shear properties and water connectivity of wet granules at high solid content concentration

The inner liquid distribution in wet granules strongly influences their mechanical properties. In this study, we examined the shear properties (internal friction angle, cohesion, storage modulus and loss modulus) of wet granules composed of graphite particles and water, and determined their inner water connectivity using X-ray refraction contrast imaging computed tomography (CT) to elucidate their correlation. At high solid content concentration (C_SC) region (C_SC = 85 wt.%), internal friction angle of wet granules was slightly lower than that of wet granules with lower C_SC, and their cohesion becomes almost zero. Furthermore, storage modulus of wet granules at C_SC = 85 wt.% was the highest among all wet granules. The X-ray CT and scanning electron microscopy (SEM) observations revealed that the water connectivity in the wet granules was in the pendular state and graphite particles fractured under shear test at C_SC = 85 wt.%. From these results, it can be concluded that lower shear cohesion at C_SC = 85 wt.% is caused by an increase in the number of isolated liquid bridges, and particle fracture results in a decrease in the internal friction angle owing to decreasing roughness of shear plane. Furthermore, the particle fracture also resulted in the higher storage modulus at C_SC = 85 wt.% in rheological measurements.     

响应面法优化顶空固相微萃取分析茉莉加香颗粒挥发性成分

目的 建立顶空固相微萃取(headspace-solidphasemicroextraction,HS-SPME)分析茉莉加香颗粒挥发性成分的检测方法。方法 采用HS-SPME和气相色谱-质谱法(gaschromatography-massspectrometry,GC-MS),以总峰个数为指标,在选定萃取头的基础上,采用单因素实验法分析萃取温度、萃取时间、解吸时间对萃取效果的影响,根据单因素实验结果运用Box-Benhnken中心组合实验设计响应面优化萃取条件,并在最优萃取条件下对茉莉加香颗粒挥发性成分进行分析鉴定。结果 50/30μmDVB/CAR/PDMS萃取头对茉莉加香颗粒挥发性成分萃取效果较好;响应面法得到最佳萃取条件为萃取温度62℃,萃取时间26.5min,解吸时间2.6min。在最佳条件下茉莉加香颗粒共检测出61种挥发性成分,占流出组分总量的87.97%,其中酯类16种、烯烃类21种、烷烃类7种、醛酮类3种、酚类1种、醇类2种、杂环类1种、其他类10种。结论 本研究建立了茉莉加香颗粒挥发性成分的检测方法,此方法快速准确,为加香颗粒挥发性成分的检测研究提供技术支撑。     

微波提取荔枝多糖及冲剂的研制

采用正交试验法优化了微波提取荔枝多糖的条件,研究了多糖冲剂制备工艺,并用苯酚-硫酸法对荔枝多糖冲剂中多糖含量进行测定.结果表明,以水为溶剂,荔枝多糖最佳提取条件为:提取时间10min,微波功率为640 W,液料比为9∶1.荔枝多糖冲剂配方为:粗多糖∶可溶性淀粉∶甜蜜素为1∶4∶0.04,冲剂中多糖含量为6.226%.     

桑椹汁保健泡腾冲剂的研制

以桑椹汁和桑叶为主要原料,添加白砂糖、柠檬酸、香精、L-赖氨酸盐酸盐等辅料,经调配、过滤、浓缩、干燥、灭菌、包装等工序加工而成的桑椹汁保健泡腾冲剂,其色泽美观、口感较好、风味独特、溶解和泡腾性好,是具有较强保健作用的产品。