基于针铁矿强化乙酸产甲烷过程的ADM1模型修正与模拟研究

为探究针铁矿对乙酸产甲烷途径的调控作用,利用ADM1模型（厌氧消化1号模型）对添加针铁矿的产甲烷过程进行模拟研究.首先引入氧化还原介质作为新变量,模拟SAO（syntrophic acetate oxidation,互营乙酸氧化）过程中的种间电子转移,进而建立包含DIET（direct interspecies electron transfer,直接种间电子传递）产甲烷过程的ADM1修正模型,最后利用该模型对各产甲烷途径的贡献进行评价.结果表明:①c（乙酸）分别为12和20 mmol/L时,添加40~2 000 mg/L针铁矿明显提高了乙酸体系的产甲烷速率.②修正的ADM1模型能够有效地模拟针铁矿强化乙酸产甲烷过程.③12、20 mmol/L乙酸体系的敏感性参数km_Xst（最大比乙酸氧化速率）校准值分别从1.02、1.46升至1.76、2.03,km_DIET（最大比电子消耗速率）校准值分别从0.78、1.48升至2.44、3.99,表明添加针铁矿提高了互营体系的种间电子传递速率.修正的ADM1模型对各产甲烷途径贡献的计算结果显示,针铁矿对DIET过程的强化作用与其添加量呈正相关,添加2 000 mg/L针铁矿试验组[c（乙酸）为12 mmol/L]中DIET和SAO产甲烷的贡献率相比对照组分别提升了117.99%和130.73%.研究显示,修正的ADM1模型能够有效地模拟针铁矿对乙酸产甲烷过程的强化作用,并且能用于评价各产甲烷途径的贡献.      

The effect of salinity on waste activated sludge alkaline fermentation and kinetic analysis

The effect of salinity on sludge alkaline fermentation at low temperature(20°C) was investigated, and a kinetic analysis was performed. Different doses of sodium chloride(Na Cl, 0–25 g/L) were added into the fermentation system. The batch-mode results showed that the soluble chemical oxygen demand(SCOD) increased with salinity. The hydrolysate(soluble protein, polysaccharide) and the acidification products(short chain fatty acids(SCFAs), NH+4–N, and PO_4~(3-)–P) increased with salinity initially, but slightly declined respectively at higher level salinity(20 g/L or 20–25 g/L). However, the hydrolytic acidification performance increased in the presence of salt compared to that without salt.Furthermore, the results of Haldane inhibition kinetics analysis showed that the salt enhanced the hydrolysis rate of particulate organic matter from sludge particulate and the specific utilization of hydrolysate, and decreased the specific utilization of SCFAs. Pearson correlation coefficient analysis indicated that the importance of polysaccharide on the accumulation of SCFAs was reduced with salt addition, but the importance of protein and NH+4–N on SCFA accumulation was increased.     

活性炭生物转盘法处理化工废水

使用固定剂将颗粒状活性炭固定在盘片上，制成了一种新型生物转盘盘片——活性炭生物转盘盘片。采用一级微型生物转盘法处理模拟化工废水，对比了活性炭、石英砂、聚丙烯3种生物转盘的处理效果。实验结果表明，活性炭生物转盘对COD的去除效果好于其他两种转盘。在进水COD为600mg／L、水力停留时间为6h、盘片转速为4r／min的条件下，活性炭生物转盘对COD的去除率可达71．3％。此外，活性炭生物转盘还有较强的耐有机负荷冲击能力。在废水处理过程中，活性炭仅在挂膜的前7天起吸附作用，挂膜成功后生物降解起主导作用。     

Effect of Sequential Mixing and Compounding Conditions on Cellulose Acetate/Layered Silicate Nanocomposites

Injection molded nanocomposites have been successfully fabricated from cellulose acetate (CA), eco-friendly triethyl citrate (TEC) plasticizer, and organically modified clay with and without maleic anhydride grafted cellulose acetate butyrate (CAB-g-MA) as a compatibilizer. The effects of processing conditions such as mixing methods, pre-plasticizing times, extruder retention times (RT) and addition of compatibilizer on the performance of these nanocomposites have been evaluated. The cellulosic plastic with CA/TEC (80/20 wt%) was used as the polymer matrix for nanocomposite fabrication. The morphologies of these nanocomposites were evaluated through X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies. The mechanical properties of the nanocomposites were measured and have been correlated with the XRD and TEM observations. From all of the sequential mixing methods used, powder–powder mixing leads to the most transparent nanocomposites. Cellulosic plastic-based nanocomposites obtained using increased pre-plasticizing times and RT showed better exfoliated structures. In the system containing compatibilizer, the minimum retention time required for obtaining almost completely exfoliated hybrid nanocomposites was shorter than in the system without compatibilizer.     

高分子凝胶球去除废水中重金属离子的研究

用海藻酸钠（SA）、海藻酸钠-聚乙烯醇（SA—PVA）、海藻酸钠-聚氧化乙烯（SA—PEO）凝胶球作为吸附剂吸附溶液中的Pb^2＋。探讨了凝胶球固定化时间、吸附时间、溶液pH值、溶液初始浓度对Pb^2＋去除率的影响,并对吸附动力学方程进行了分析。结果表明：固定化时间对去除率的影响较小;反应速率较快,吸附时间在10min时,三种凝胶球对Pb^2＋的去除率就分剐达到了80％、82％和88％,吸附时间在2h后基本达到吸附平衡,三种凝胶球对Pb^2＋的吸附能力为：SA—PGE〉SA—PVA〉SA;三种凝胶球吸附铅离子的行为均符合一级反应动力学方程;溶液的pH在4～6时有较高的去除率;三种凝胶球对不同金属的吸附能力为Pb^2＋〉Cu^2＋〉Cd^2＋;饱和吸附后的三种凝胶球均可以再生利用。     

乙酸铅对PC12细胞形态的影响

为了从形态学角度研究铅诱导细胞凋亡的机制,用100 μmol·L-1乙酸铅对PC12细胞进行染毒24 h,检测细胞整体形态、细胞骨架和细胞超微结构的改变.实验结果显示:乙酸铅染毒24 h后.细胞整体形态和细胞骨架无明显改变.但电子显微镜下已出现细胞核固缩;线粒体肿胀、正常结构消失并伴有空泡化;胞内出现鼓泡等现象.结合前期研究结果,推测线粒体在铅诱导细胞凋亡中起了重要作用.而细胞骨架不参与此过程.     

海藻酸钠-钙-铁凝胶球对Cr_2O_7~(2-)吸附的研究

本实验对海藻酸钠在氯化钙、氯化铁溶液中的成球特性,以及对SA-Ca、SA-Fe、SA-Ca-Fe凝胶球吸附Cr2O72-特性进行了研究。结果表明,SA-Ca凝胶球对Cr2O72-没有吸附能力,SA-Fe和SA-Ca-Fe凝胶球对Cr2O72-去除率均达到97%以上,但SA-Fe凝胶球成球性差,机械强度低,易碎。SA-Ca-Fe凝胶球吸附Cr2O72-符合Langmuir型,其最大吸附量为13.497mg/g。吸附属于单分子层吸附,凝胶球网络中的Fe3+与溶液中Cr2O72-发生化学反应,生成Fe2(Cr2O7)3。     

Effects of phosphorus and nitrogen limitation on PHA production in activated sludge

The e ects of phosphorus and nitrogen limitation on polyhydroxyalkanoate (PHA) production and accumulation by activated sludge biomass with acetate as a carbon source were investigated. Pre-selected influent carbon-phosphorus (C:P, W/W) of 100, 160, 250, 500 and 750, and carbon-nitrogen (C:N, W/W) of 20, 60, 100, 125 and 180 were applied in the phosphorus limitation experiments and the nitrogen limitation experiments, respectively. The maximum PHA accumulation up to 59% of the cell dry weight with a PHA productivity of 1.61 mg PHA/mg COD consumed was observed at the C:N 125 in the nitrogen limitation experiment. This value was much higher than that obtained in previous studies with a normal substrate feeding. The study showed that activated sludge biomass would produce more polyhydroxybutyrate than polyhydroxyvalerate under the stress of nutrient limitation, especially under phosphorus limitation conditions. The experimental result also indicated that both phosphorus and nitrogen limitation may cause sludge bulking.     

燃煤烟气脱硫石膏在新疆盐碱土壤改良中的应用研究

以燃煤烟气脱硫石膏作为化学改良剂,在新疆克拉玛依地区进行碱化土壤改良,土壤改良后种植新疆杨（Populus bolleana Lauche）、白榆（Ulmus pumila L.）、沙棘（Hippohgae rhamnoides L）。分析了烟气脱硫石膏对盐碱地土壤理化性质和树木生长状况的影响。结果表明：处理区土壤的pH值和全盐量比对照区有明显降低,处理区的原始碱化度越高,改良后碱化度的下降幅度越大,而且表层土壤中碱化度的下降最为明显,从29.9%下降到1.43%。改良后树木的平均成活率为71%,比对照区树木的成活率高41%,用燃煤烟气脱硫石膏改良新疆克拉玛依地区碱化土壤种植树木具有极大的推广应用价值。     

沉积物和土壤中磷的生物有效性评估新方法

利用自制的氧化铁/醋酸纤维素复合膜(FeO/CAM)发展了一种沉积物和土壤磷的生物有效性评估的新方法. 结果表明:从沉积物和土壤中解吸的生物有效磷(FeO-P)含量随时间增加而增加,至16～20h左右,解吸过程接近平衡;随着土/水比增大而减小,至20～30g/L左右逐渐趋于平缓,且相对标准偏差较小;膜面积为20～30cm²时FeO-P含量差别较小,且相对标准偏差也较小;适当提高振荡频率(一般200r/min左右),有利于促进FeO-P的提取动力学过程.在用于评估水体沉积物和土壤解吸磷的生物有效性方面,FeO/CAM膜克服了氧化铁浸渍滤纸的缺点,易于商品化,具有更好的应用前景.