铁催化分解二甲硫醚制备碳纳米管的研究

以二甲硫醚为碳源,Fe/MgO为催化剂,采用化学气相沉积法制备了碳纳米管。通过SEM、Raman、XRD、TEM表征方法研究了实验合成条件对碳纳米管产物的形貌和微结构的影响。结果表明,二甲硫醚的蒸汽浓度对碳纳米管的形貌和产量有重要影响。较高的二甲硫醚浓度会使催化剂的活性降低,制备出的碳纳米管较短且石墨化程度也较差。生长碳纳米管的最佳二甲硫醚浓度范围为2.69%～3.86%,且碳纳米管产物中有Y型碳纳米管的生成,并对其生长机理进行了初步讨论。     

无泡曝气膜生物反应器去除生活污水有机物的研究

以聚丙烯中空纤维作为无泡曝气膜生物反应器(MABR)生物膜载体,采用循环挂膜法进行聚丙烯中空纤维表面生物膜的培养,研制出一台小型MABR实验装置.在对生活污水的实验研究中获得了对化学需氧量(COD)和固体悬浮物(SS)良好的去除效果.研究表明:中空纤维内腔氧气压力在0.02～0.1 MPa的范围内对MABR去除COD的能力具有较小的影响;当反应器中污水的循环次数达到7.5次/h时,污水的循环流速对MABR的COD降解效果没有显著影响.在适宜的条件下,HRT为10 h时,MABR能够较容易地使污水的出水COD保持在50 mg/L以下,SS保持在15 mg/L以下.     

固定管板式UHMW-PE过滤器的研究

在石油、化工、造纸、医药等生产工艺设备中使用的PE滤芯过滤器,反吹易使滤芯中的固体颗粒吹不干净,并且容易断裂,滤芯更换不方便。为了能使设备长周期运行,解决反吹滤芯断裂问题,因此提出采用固定管板式UHMW-PE过滤器。     

生物医用镁合金表面PLGA涂层研究

镁及镁合金作为可降解吸收生物医用材料的研究已得到关注,但与传统可降解材料相比其腐蚀降解较快,可能导致提前失效.以高纯的Mg-Zn合金为研究材料,采用浸涂提拉法在其表面得到PLGA涂层.结果表明,PLGA涂层致密均匀,耐蚀性好,降解周期长,可以有效保护镁合金在植入初期不发生腐蚀降解,延长其发挥功能的时间,达到良好的医学适用性.     

一种过滤器微粒沉积量实时检测技术的研究

本根据过滤器微粒过滤及再生的需要,提出了一种过滤体微粒沉积量实时检测技术。叙述了微粒检测原理,介绍了从功率容量的要求出发对检测天线进行设计的方法;并对实际测量结果及影响因素进行了分析。通过实验结果验证了这一技术的可行性。     

膜生物反应器处理冲厕海水的试验研究

主要研究了膜生物反应器对冲厕海水中主要污染物的处理效果以及盐度对生物反应器内微生物群落和活性污泥特性的影响.结果表明,微生物经培养驯化后能适应不同的海水盐度,膜生物反应器对冲厕海水中的COD和氨氮的去除率分别达到86%和93%.随着盐度的提高,污泥沉降性能变差.盐度的冲击对膜生物反应器处理效果有一定影响,系统需要较为恒定的盐度条件.     

液氮流过烧结金属过滤器的压降特性研究

以液氮作为需要净化的低温液体,以二氧化碳为液氮的杂质进行了过滤试验.搭建了试验台,进行了过滤实验,在试验中测试了过滤过程中压降变化和被过滤流体流量等参数,对试验结果进行了分析,得到了过滤器压降与工况参数之间的关系.同时应用基于达西定律的烧结金属过滤器的压降计算模型,对实验工况的过滤器的压降进行预测.并将模型计算值与实验数据进行比较得出,结果表明模型较好的预测了液氮在烧结金属过滤器中流动的压力损失情况,同时指出了该模型的不足之处和以后的改进方向.     

功能性空调过滤器材料的性能实验研究

开创性地把光催化技术和微胶囊相变材料技术有机地结合起来,开发了纳米微胶囊相变功能型空调过滤器材料,在对它的杀菌效果和调温等性能研究的基础上,分析了空调过滤器的过滤机理,设计了实验流程,参照ANSI／AHAMAC-1—1988标准建造了实验室,对功能型空调过滤器过滤效率进行了实验。最后对实验结果进行了一定的分析,并展望了功能型空调过滤器材料的应用前景。     

活性炭纤维过滤器祛除室内气态污染物的实验研究

以平板、旁通、折叠三种结构形式的活性碳纤维过滤器为实验对象，选择甲醛和氨气作为室内典型污染物，以分光光度法测定在变风量和变污染物浓度的条件下过滤器的吸附过滤效果；实验数据的分析表明，从综合角度考虑，平板式过滤器较为理想，折叠式效率较高，但阻力相对偏大，而旁通式则效率偏低；提出了一些对活性碳纤维过滤器的发展和改进有价值的建议。     

金属液在泡沫陶瓷过滤器中通用流动模型的研究

本文运用管束理论建立了金属液在泡沫陶瓷过滤器中通用流动模型,并采用计算机辅助计算钢液通过泡沫陶瓷过滤器压力损失的补偿量。实践表明,该模型与实际情况基本一致。     

Sorption and degradation of bisphenol A by aerobic activated sludge

Laboratory-scale batch experiments were conducted to investigate the sorption and degradation of bisphenol A (BPA) at μg/L range in an aerobic activated sludge system. The sorption isotherms and thermodynamics indicated that the sorption of BPA on sludge was mainly a physical process in which partitioning played a dominating role. The values of sorption coefficient K_oc were between 621 and 736 L/kg in the temperature range of 10–30 °C. Both mixed liquor suspended solid (MLSS) and temperature influenced BPA sorption on sludge. The degradation of BPA by acclimated activated sludge could be described by first-order reaction equation with the first-order degradation rate constant of 0.80 h⁻¹ at 20 °C. The decrease of initial COD concentration and the increase of MLSS concentration and temperature enhanced BPA degradation rate. The removal of BPA in the activated sludge system was characterized by a quick sorption on the activated sludge and subsequent biodegradation.     

Study of Cu(II) biosorption by dried activated sludge: effect of physico-chemical environment and kinetics study

Biosorption is a recent technology used to remove heavy metal ions from aqueous solutions. The biosorption of copper ions from aqueous solution by dried activated sludge was investigated in batch systems. Effect of solution pH, initial metal concentration and particle size range were determined. The suitable pH and temperature for studied conditions were determined as 4.0 and 20 °C, respectively. The theoretical max biosorption capacity of activated sludge was 294 mg g⁻¹ at 20 °C for <0.063 mm particle size. The equilibrium data fitted very well to both Langmuir and Freundlich isotherm models. The pseudo first and second-order kinetic models were used to describe the kinetic data. The experimental data fitted to second-order kinetic model. The particle size and initial metal concentration were effected the biosorption capacity of dried activated sludge. An increase in the initial metal concentration increases of biosorption capacity, which also increases with decreasing particle size. Dried activated sludge has different functional groups according to the FT-IR results.     

Removal of nitroimidazole antibiotics from aqueous solution by adsorption/bioadsorption on activated carbon

The objective of the present study was to analyse the behaviour of activated carbon with different chemical and textural properties in nitroimidazole adsorption, also assessing the combined use of microorganisms and activated carbon in the removal of these compounds from waters and the influence of the chemical nature of the solution (pH and ionic strength) on the adsorption process. Results indicate that the adsorption of nitroimidazoles is largely determined by activated carbon chemical properties. Application of the Langmuir equation to the adsorption isotherms showed an elevated adsorption capacity (X_m = 1.04–2.04 mmol/g) for all contaminants studied. Solution pH and electrolyte concentration did not have a major effect on the adsorption of these compounds on activated carbon, confirming that the principal interactions involved in the adsorption of these compounds are non-electrostatic. Nitroimidazoles are not degraded by microorganisms used in the biological stage of a wastewater treatment plant. However, the presence of microorganisms during nitroimidazole adsorption increased their adsorption on the activated carbon, although it weakened interactions between the adsorbate and carbon surface. In dynamic regime, the adsorptive capacity of activated carbon was markedly higher in surface water and groundwater than in urban wastewaters.     

Removal and recovery of gas-phase element mercury by metal oxide-loaded activated carbon

The reusability of Co(3)O(4) (AC-Co), MnO(2) (AC-Mn) and CuCoO(4) (AC-CC) loaded activated carbon (AC) and their element mercury removal efficiency had been studied using a laboratory-scale fixed-bed reactor under simulated flue gas conditions. Tests showed that spent AC-Co could be regenerated through heating at 673 K under N(2) atmosphere and the enrichment regenerated Hg(0) could be collected to eliminate the secondary pollution. Regenerated AC-Mn and AC-CC's Hg(0) removal efficiency decreased greatly due to AC's decomposition and MnO(2)'s crystal structure variation. Compared with AC and metal oxides, metal oxide-loaded AC had higher Hg(0) capture ability and capacity due to AC huge surface areas and lots of function groups. TGA analysis results showed that AC-Co and AC-Mn's HgO adsorptive capacity at 523 K reached 19.8 mg g(-1) and 5.21 mg g(-1), respectively. High loading values and adsorption temperatures were beneficial to AC-Co's Hg(0) removal efficiency. However, CuCoO(4) and MnO(2)'s AC decomposition ability had negative effect on AC-CC and AC-Mn's performance, respectively, especially at high adsorption temperatures and loading values. SO(2) tests showed that AC-CC had higher anti SO(2)-poisoning ability than AC-Co and AC-Mn.     

Study of the aerobic biodegradation of coke wastewater in a two and three-step activated sludge process

A laboratory-scale biological plant composed of two aerobic reactors operating at 35 degrees C was used to study the biodegradation of coke wastewater. The main pollutants to be removed are organic matter, especially phenols, thiocyanate and ammonium nitrogen. The concentrations of the main pollutants in the wastewater during the study ranged between 922 and 1,980 mg COD/L, 133 and 293 mg phenol/L, 176 and 362 mg SCN/L and 123 and 296 mg NH(4)(+)-N/L. The biodegradation of these pollutants was studied employing different hydraulic residence times (HRT) and final effluent recycling ratios in order to minimize inhibition phenomena attributable to the high concentrations of pollutants. During the optimisation of the operating conditions, the removal of COD, phenols and thiocyanate was carried out in the first reactor and the nitrification of ammonium took place in the second. The best results were obtained when operating at an HRT of 98 h in the first reactor and 86 h in the second reactor, employing a recycling ratio of 2. The maximum removal efficiencies obtained were 90.7, 98.9, 98.6 and 99.9% for COD, phenols, thiocyanate and NH(4)(+)-N, respectively. In order to remove nitrate, an additional reactor was also implemented to carry out the denitrification process, adding methanol as an external carbon source. Very high removal efficiencies (up to 99.2%) were achieved.     

中国泥炭资源标准化体系建设研究

泥炭是宝贵的自然资源,具有重要的生态功能和利用价值。构建泥炭标准化体系对于推进我国泥炭资源有效管理和合理利用具有重要作用。本文通过分析我国泥炭资源管理和应用现状,以及国内外泥炭标准化发展,提出了我国泥炭标准化体系建设的思路和框架。     

Removal of congo red from aqueous solution by adsorption onto acid activated red mud

The objective of this study is to remove the congo red (CR) anionic dye, from water by using the acid activated red mud in batch adsorption experiments. The effects of contact time, pH, adsorbent dosage and initial dye concentration on the adsorption were investigated. The pH of the dye solution strongly affected the chemistry of both the dye molecules and activated red mud in an aqueous solution. The effective pH was 7.0 for adsorption on activated red mud. It was found that the sufficient time to attain equilibrium was 90 min. The adsorption isotherms were analyzed using the Langmuir, the Freundlich, and the three parameter Redlich-Peterson isotherms. The Langmuir isotherm was the best-fit adsorption isotherm model for the experimental data obtained from the non-linear chi-square statistic test.     

Removal of phenol from aqueous solutions by adsorption onto activated carbon prepared from biomass material

Activated carbon derived from rattan sawdust (ACR) was evaluated for its ability to remove phenol from an aqueous solution in a batch process. Equilibrium studies were conducted in the range of 25–200 mg/L initial phenol concentrations, 3–10 solution pH and at temperature of 30 °C. The experimental data were analyzed by the Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherm models. Equilibrium data fitted well to the Langmuir model with a maximum adsorption capacity of 149.25 mg/g. The dimensionless separation factor R_L revealed the favorable nature of the isotherm of the phenol-activated carbon system. The pseudo-second-order kinetic model best described the adsorption process. The results proved that the prepared activated carbon was an effective adsorbent for removal of phenol from aqueous solution.     

Simultaneous removal of phenol, ammonium and thiocyanate from coke wastewater by aerobic biodegradation

A laboratory-scale activated sludge plant composed of a 20 L volume aerobic reactor followed by a 12 L volume settling tank and operating at 35 degrees C was used to study the biodegradation of coke wastewater. The concentrations of ammonium nitrogen (NH(4)(+) -N), phenols, chemical oxygen demand (COD) and thiocyanate (SCN(-)) in the wastewater ranged between 504 and 2,340, 110 and 350, 807 and 3,275 and 185 and 370 mg/L, respectively. The study was undertaken with and without the addition of bicarbonate. The addition of this inorganic carbon source was necessary to favour nitrification, as the alkalinity of the wastewater was very low. Maximum removal efficiencies of 75%, 98% and 90% were obtained for COD, phenols and thyocianates, respectively, without the addition of bicarbonate. The concentration of ammonia increased in the effluent due to both the formation of NH(4)(+) as a result of SCN(-) biodegradation and to organic nitrogen oxidation. A maximum nitrification efficiency of 71% was achieved when bicarbonate was added, the removals of COD and phenols being almost similar to those obtained in the absence of nitrification. Batch experiments were performed to study the influence of pH and alkalinity on the biodegradation of phenols and thiocyanate.     

Removal of chromium Cr(VI) by low-cost chemically activated carbon materials from water

Low-cost, chemically activated carbon materials, Pellet-600 and PVA-300, were prepared at relatively low temperatures and show more effective removal efficiency of Cr(VI) from water than commercially available activated carbons tested. The Pellet-600 is a pelletized carbon material with high mesoporous volumes and surface area, and the PVA-300 is composed of a high surface area carbon coating on a fiberglass mat substrate. A much faster adsorption kinetics and a much higher adsorption capacity for Cr(VI) are achieved by the Pellet-600. At very low concentrations of Cr(VI), the PVA-300 displays a strong adsorption ability for Cr(VI). XPS data show an increase in the atomic ratio of Cr/C and oxidation of carbon materials after adsorption of Cr(VI). These results suggest that a high content of mesopores with a high surface area and surface functional groups greatly improve the Cr(VI) removal efficiency from water.