炭纤维载体固定床厌氧发酵启动运行效果实验

以开发高效率、抗冲击性能强的高浓度有机废水沼气发酵技术为目的,用传统的 UASB反应器作为对照,研究了以炭纤维为生物膜载体的固定床厌氧反应器的启动运行效果。反应器进口废水 COD 为 5 000 mg/L, 水力停留时间 (HRT) 由213 h 逐步缩短为35 h,进水有机容积负荷(OLR)由0.56 kg COD/ (m³·d)提到3.45 kg COD/(m³·d)。结果表明,固定床反应器厌氧发酵的效率比对照高,出水 pH 值也比对照稳定;运行到第 50 d 时,固定床厌氧反应器和对照的 COD去除率分别由第 7 d 的36.56%和33.58%上升到87.9%和62.6%;固定床厌氧反应器的容积比产气率最高为1.16 m³/(m³·d),累计产气量为415.59 L,而对照的容积比产气率最高值仅为0.31 m³ /(m³·d),累计产气量为 71.66 L,前者最高容积比产气率和累计产气量分别是后者的3.74倍和5.78倍。固定床厌氧反应器的启动速度、COD 去除率和产甲烷效率显著地高于对照反应器。     

二段生物接触氧化工艺在中水回用中的特性研究

以规模小区生活污水为水源,对采用聚丙烯网状填料和强化炉渣组合填料的二段生物接触氧化工艺（以下简称二段法）进行了试验研究,试验针对本工艺的各项技术指标、影响因素以及各相关参数进行了较系统的试验测试。结果表明,反应器在第一接触氧池HRT为20 min、气水比为6∶1和第二接触氧池HRT为25 min、气水比为5∶1条件下,接触氧化池达到最佳降碳条件;反应器在第一接触沉池上升流速5.5 m/h和第二接触沉池上升流速4.5 m/h条件下,接触沉淀池达到最佳处理条件。     

土壤重金属的植物污染化学研究进展

针对中国土壤重金属污染加剧的趋势,为改善土壤环境质量和保障农产品安全,提出了土壤重金属的植物污染化学研究领域.结合多年的研究工作,从土壤重金属的植物根际化学行为、土壤重金属的植物吸收与解毒机制和重金属污染土壤的植物-微生物交互作用等方面简要阐述了土壤-植物系统中重金属的分布、存在形态、迁移转化、累积及生物学效应和控制规律的研究进展,并对将来的植物污染化学理论研究提出了展望.     

土壤渗滤对有机微污染物去除性能研究

采用土壤柱试验研究了土壤渗滤对再生水中有机微污染物的去除性能。结果表明,土壤柱对再生水中的DOC、UV₂₅₄、总氮和总磷有较好的去除效果,并具有较高的抗冲击负荷的能力;土壤表层10 cm厚度对DOC的去除起主要作用;UV₂₅₄和AOX在土壤表层10 cm厚度降解效果不明显,随着深度增加去除率逐渐升高;液相色谱有机碳探测(LC-OCD)检测结果表明,土壤柱对溶解性有机物质的去除主要体现在对多糖物质的降解上,其次是有机酸类,对腐殖质也有一定的去除作用。     

Adsorption of Pb(II) on variable charge soils amended with rice-straw derived biochar

Two Ultisols and one Oxisol from tropical regions of southern China were incubated with rice straw biochar to investigate the effect of biochar on their surface charge and Pb(II) adsorption using batch methods. The incorporation of biochar induced a remarkable increase in soil cation exchange capacity after 30 d of incubation. The incorporation of biochar significantly increased the adsorption of Pb(II) by these variable charge soils; the enhancement of adsorption of Pb(II) by these soils increased with the addition level of biochar. Adsorption of Pb(II) involved both electrostatic and non-electrostatic mechanisms; however, biochar mainly increased Pb(II) adsorption through the non-electrostatic mechanism via the formation of surface complexes between Pb²⁺ and functional groups on biochar. There was greater enhancement of biochar on the non-electrostatic adsorption of Pb(II) by the variable charge soils at relatively low pH. Therefore, the incorporation of biochar decreased the activity and availability of Pb(II) to plants through increased non-electrostatic adsorption of Pb(II) by acidic variable charge soils.     

甲烷吸附塔模拟装置阻火性能的实验研究

为了研究甲烷变压吸附提纯装置工作过程中的安全性,研制了甲烷吸附塔阻火性能模拟试验装置.通过改变吸附层厚度、空间位置和工作压力,测试点火引爆后的压力和温度,得到了爆炸火焰穿透介质层的规律,并按照各个因素对火焰穿透性能的影响建立了指数评价公式模型,根据该模型可以判断甲烷吸附塔内发生火焰传播的可能性.     

镁粉生产工艺防爆方法及存在的问题

镁粉生产工艺具有较大的火灾爆炸危险性.从预防爆炸发生和减缓爆炸后果两方面对我国镁粉生产工艺的防爆方法进行了比较和分析.从着火过程理论不完善、爆炸性数据不完整和防爆方法缺乏实验依据3个方面分析了镁粉防爆存在的问题,着重分析了镁粉惰化和部分惰化方法的不足,指出了进一步加强镁粉防爆基础研究的方向.     

Aging activity of DDE in dissimilar rice soils in a greenhouse experiment

A green-house study was conducted in late 2005 to investigate the aging behavior of p,p'-DDE in two types of soil, Hydragric Anthrosols (An) and Hydragric Acrisols (Ac), according to the World Reference Base (WRB) [FAO/ISRIC/ISSS. 1998. World reference base for soil resources. World soil resources reports, Rome. p. 87]. Paddy rice and dry rice were grown in submerged paddy soils and non-submerged upland soils, respectively. The concentration of extractable p,p'-DDE in fresh DDE-spiked soils was 746.2ngg(-1). During the first few weeks of the experiment, the extractability of p,p'-DDE became increasingly low as the aging period prolonged. However, certain amount of p,p'-DDE that had been captured by soil minerals and organic matter (OM) could be released and became extractable in the later period. The extractability of p,p'-DDE in submerged soils was significantly lower than that in non-submerged soil, because flooding could increase the binding of pollutants to soil particles. The plantation of both dry rice and paddy rice slowed down the aging process of p,p'-DDE. After one month's growth of rice, p,p'-DDE bound to soil particles was released and became extractable. The OM and silt content of An are higher than that of Ac, resulting in more bound residues and relative lower extractability of p,p'-DDE in An. In addition, the extractability of p,p'-DDE could be reduced by the addition of rice straw to soils.     

Assessment of population exposure to particulate matter pollution in Chongqing, China

To determine the population exposure to PM(10) in Chongqing, China, we developed an indirect model by combining information on the time activity patterns of various demographic subgroups with estimates of the PM(10) concentrations in different microenvironments (MEs). The spatial and temporal variations of the exposure to PM(10) were illustrated in a geographical information system (GIS). The population weighted exposure (PWE) for the entire population was 229, 155 and 211 microg/m(3), respectively, in winter, summer and as the annual average. Indoor PM(10) level at home was the largest contributor to the PWE, especially for the rural areas where high pollution levels were found due to solid fuels burning. Elder people had higher PM(10) exposure than adults and youth, due to more time spent in indoor MEs. The highest health risk due to particulate was found in the city zone and northeast regions, suggesting that pollution abatement should be prioritized in these areas.     

Non-microcystin producing Microcystis wesenbergii (Komárek) Komárek (Cyanobacteria) representing a main waterbloom-forming species in Chinese waters

It is well known that several morphospecies of Microcystis, such as Microcystis aeruginosa (Kützing) Lemmermann and Microcystis viridis (A. Brown) Lemmermann can produce hepatotoxic microcystins. However, previous studies gave contradictory conclusions about microcystin production of Microcystis wesenbergii (Komárek) Komárek. In the present study, ten Microcystis morphospecies were identified in waterblooms of seven Chinese waterbodies, and Microcystis wesenbergii was shown as the dominant species in these waters. More than 250 single colonies of M. wesenbergii were chosen, under morphological identification, to examine whether M. wesenbergii produce hepatotoxic microcystin by using multiplex PCR for molecular detection of a region (mcyA) of microcystin synthesis genes, and chemical analyses of microcystin content by ELISA and HPLC for 21 isolated strains of M. wesenbergii from these waters were also performed. Both molecular and chemical methods demonstrated that M. wesenbergii from Chinese waters did not produce microcystin.