强化循环厌氧反应器处理印染废水的中试启动研究

应用自主研制的强化循环厌氧反应器(SCAR)中试规模处理实际印染废水,研究反应器的启动特性。反应器接种厌氧颗粒污泥后启动运行83 d,形成连续内循环并实现了对印染废水处理的高效稳定运行。在进水COD浓度1 000~3 650 mg/L、系统容积负荷0.7~6.4 kg/(m3·d)条件下,废水COD和色度平均去除率分别达到55%和73%。反应器内较高浓度的NH+4-N保证了系统pH的稳定性,350~600 mg/L的NH+4-N浓度没有对强化循环厌氧反应器产生抑制作用,系统内也没有出现VFA(以乙酸计)积累。启动过程中,厌氧颗粒污泥的粒径增大、沉降性能变好。启动实验完成时,反应器内微生物的脱氢酶活性(以TF计)和辅酶F420浓度分别为3.4973 mg/(g·h)和0.1872μmol/g。     

利用白云石石灰去除与回收污泥厌氧消化液中氮和磷

以白云石石灰为实验材料去除与回收污泥厌氧消化液中的氮磷,通过小试实验研究不同投药固液比S/L、初始pH值、反应温度、搅拌速度及反应时间对去除与回收氮磷效果的影响。实验结果表明,在最佳投药固液比S/L为300mg/L,最佳初始pH值范围为8.5~9.5,反应温度为25.0℃,搅拌速度为150 r/min,反应时间为24 h条件下,氨氮(NH+4-N)和磷(PO3-4-P)的去除率分别为37.26%和89.60%。利用X射线衍射仪(XRD)、扫描电镜(SEM)对沉淀产物进行了表征,通过分析可知沉淀产物中含有磷酸铵镁(MAP),可实现废水中氮磷经济有效的回收。     

废旧冰箱拆解聚氨酯泡沫塑料制备PU/PP复合材料

利用废旧冰箱拆解的聚氨酯泡沫塑料(PU)和聚丙烯(PP)、聚丙烯接枝马来酸酐(PP-g-MAH)为原料,采用物理化学回收技术制备PU/PP复合材料。用正交实验法分析PU填充量、PU粒径和PP-g-MAH 3个因素对PU/PP复合材料力学性能影响的显著性。结果表明,PU填充量对PU/PP复合材料拉伸性能有显著影响,对冲击性能和弯曲性能没有显著影响;在本文的实验范围内,PU粒径对PU/PP复合材料的力学性能影响不大;而PP-g-MAH投加量对PU/PP复合材料具有一定的影响。确定的优化工艺配方为:PU 40%;PU粒径选择2.00 mm;PP-g-MAH投加量10%。采用优化工艺制备的PU/PP复合材料的密度为1 042.88 kg/m3;冲击强度为2.9 kJ/m2;拉伸强度为10.30 MPa;拉伸模量为1 100 MPa;弯曲强度为18.5 MPa;弯曲模量为733 MPa。     

石墨气体扩散电极的制备与性能优化

电极的制备工艺及参数直接影响电极材料的活性。主要考察了C/PTFE质量比、碾压压力、煅烧温度、造孔剂NH4HCO3及稀土掺杂等因素对电极产出H2O2的影响规律。研究结果表明,电极最佳制备条件为:石墨和PTFE质量比为2∶1、石墨、造孔剂和稀土元素质量比为6∶1∶1、碾压压力10 MPa、煅烧温度330℃。在pH=3、电解质Na2SO4浓度为0.05mol/L条件下,电解2 h后,改性电极产生的H2O2从95 mg/L提高到350 mg/L,提高了268.4%。     

Probing the distribution and contamination levels of 10 trace metal/metalloids in soils near a Pb/Zn smelter in Middle China

The horizontal and vertical distribution patterns and contamination status of ten trace metal/metalloids (Ag, Bi, Co, Cr, Ge, In, Ni, Sb, Sn, Tl) in soils around one of the largest Chinese Pb–Zn smelter in Zhuzhou City, Central China, were revealed. Different soil samples were collected from 11 areas, including ten agricultural areas and one city park area, with a total of 83 surface soil samples and six soil cores obtained. Trace metal/metalloids were determined by inductively coupled plasma–mass spectrometry after digestion by an acid mixture of HF and HNO₃. The results showed that Ag, Bi, In, Sb, Sn, and Tl contents decreased both with the distance to the Pb–Zn smelter as well as the soil depth, hinting that these elements were mainly originated from the Pb–Zn smelting operations and were introduced into soils through atmospheric deposition. Soil Ge was influenced by the smelter at a less extent, while the distributions of Co, Cr, and Ni were roughly even among most sampling sites and soil depths, suggesting that they were primarily derived from natural sources. The contamination status, as revealed by the geo-accumulation index (I _geo), indicated that In and Ag were the most enriched elements, followed by Sb, Bi, and Sn. In general, Cr, Tl, Co, Ni, and Ge were of an uncontaminated status.     

净化SO2的生物膜填料塔中微生物类群分析

对净化废气中SO2的生物膜填料塔内的微生物进行了分离纯化并做鉴定,得到一株嗜酸性氧化硫硫杆菌（Acidithiobacillus thiooxidans IEL001）和一株分类地位非常接近链二孢属（Bispora sp.）的极端嗜酸真菌IEL002,生物膜填料塔内的极端酸性环境和有机营养的缺乏导致生物膜上的微生物种类较为单一,多样性程度不高。本研究还发现IEL002自身并不能氧化单质硫,但它能促进Acidithiobacillus thiooxidans IEL001对单质硫的氧化。     

固定化微生物法去除模拟渗滤液中氨氮的研究

采用固定化微生物曝气生物滤池（I-BAF）技术成功处理了模拟垃圾渗滤液,探讨了pH和溶解氧（DO）对系统脱氮性能的影响。结果表明,固定化微生物曝气生物滤池反应系统启动迅速,运行稳定,可以有效去除模拟垃圾渗滤液中的有机物和氨氮,其去除率分别达到97.1%和99.9%。在pH为7.5～8.5之间,DO 4.0 mg/L左右的条件下对模拟垃圾渗滤液中氮的去除最为有利,同步硝化反硝化效率以及总氮去除率均达到最高,分别为96.2%和94.3%。这主要是由于I-BAF系统中大孔载体提供了厌氧-兼氧-好氧的微环境,使硝化和反硝化反应在同一个反应器内发生,共同作用实现模拟垃圾渗滤液中总氮的去除。     

催化湿式氧化预处理造纸黑液

采用连续式固定床反应器,利用自制稀土类复合金属氧化物催化剂对草浆造纸黑液进行了催化湿式氧化(CWAO)预处理研究.通过正交实验确定了最佳工艺条件为:进水COD 40 800 mg/L,空速0.8h-1,反应温度260℃,反应压力6.5 MPa.在此最佳条件下进行实验,COD去除率达90％.经CWAO工艺处理后,草浆造纸...     

Effects of T-2 toxin on histopathology,fatty acid and water distribution of shrimp (Litopenaeus vannamei) muscle

T-2 toxin (T-2), one of the naturally occurring mycotoxins, often accumulates in aquatic animals from contaminated feed. Shrimp (n?=?30 per group) were fed with different concentrations (0, 0.5, 1.5, 4.5 and 13.5?mg kg^?1) of T-2 for 20?days. Changes in histopathology, fatty acid and water distribution of shrimp muscle were analyzed. Histopathology of shrimp muscle showed dose-dependent marked degenerative and necrotic changes on exposure to dietary T-2. The T-2 significantly (P?<?0.05) affected the muscle fatty acid composition. ∑SFA, ∑MUFA and ∑PUFA initially decreased and then increased slowly in the high-dosed groups. C16:0, C18:1n-9 and C18:2n-6 were the main saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA), respectively. Also, T-2 significantly affected water distribution in shrimp muscle. High doses of T-2 reduced free water content, resulting in a reduction in the water holding capacity and hence changes to the shrimp muscle quality. Collectively, these results illustrated that T-2 significantly affects the fatty acid and water distribution, and also muscle histopathology, all of which would result in a reduction in the quality and nutritional value of shrimp.     

单宁为模板制备纳米二氧化钛 及其对钍的吸附性能

以杨梅单宁(BT)为模板,水热法合成纳米二氧化钛(BT-NTO)。采用XRD、FTIR、SEM和TEM技术对BT-NTO的结构及形貌进行了表征。将BT-NTO用于吸附溶液中的Th~(4+),在溶液pH为3.5、温度为25℃、Th~(4+)初始浓度为0.5 mmol/L的条件下,BT-NTO对Th~(4+)的吸附量为0.905 8 mmol/g;吸附过程符合准二级动力学方程和Langmuir等温吸附方程;溶液中共存的Zn~(2+)、Ni~(2+)、Co~(2+)、Sr~(2+)、Yb~(3+)、Nd~(3+)、Sm~(3+)、Gd~(3+)、La~(3+)、Cl-、ClO4-离子对Th~(4+)吸附量影响较小;BT-NTO的重复使用性能较好。