光催化氧化法降解废气中苯系物的研究

采用溶胶-凝胶工艺制备以多孔泡沫镍为载体的TiO2薄膜，并用其光催化氧化降解挥发性苯系物(苯、甲苯和二甲苯)。考察了催化剂粒径、反应时间、苯系物的初始浓度、体系的相对湿度和反应温度等因素对苯系物去除率的影响。结果表明，以粒径20．7nm的TiO2为催化剂、甲苯初始质量浓度为200mg/m^3、体系的相对湿度为5％、反应温度为20—50℃、反应时间为60min条件下，甲苯的去除率达76％以上。     

旋风除尘器的压力损失及减阻措施

通过探讨引起旋风除尘器阻力损失的原因，提出了相应的减阻措施－安装导向板和内筒。     

气瓶水压试验合格标准实验研究

水压试验是气瓶检验的主要项目,将容积残余变形率超过１０％ 作为气瓶报废的标准沿用至今。笔者通过实验,分析了气瓶水压试验现行评定标准存在的问题,并对采用容积弹性变形作为评定指标进行了探讨,以期为制订更合理的水压试验标准提供有益的启示。     

Characterization of arsenate transformation and identification of arsenate reductase in a green alga Chlamydomonas reinhardtii

Arsenic (As) is a pervasive and ubiquitous environmental toxin that has created catastrophic human health problems world-wide. Chlamydomonas reinhardtii is a unicellular green alga, which exists ubiquitously in freshwater aquatic systems. Arsenic metabolism processes of this alga through arsenate reduction and sequent store and efflux were investigated. When supplied with 10 mol/L arsenate, arsenic speciation analysis showed that arsenite concentration increased from 5.7 to 15.7 mg/kg dry weight during a 7-day period, accounting for 18%–24% of the total As in alga. When treated with different levels of arsenate (10, 20, 30, 40, 50 mol/L) for 7 days, the arsenite concentration increased with increasing external arsenate concentrations, the proportion of arsenite was up to 23%–28% of the total As in alga. In efflux experiments, both arsenate and arsenite could be found in the efflux solutions. Additionally, the efflux of arsenate was more than that of arsenite. Furthermore, two arsenate reductase genes of C. reinhardtii (CrACR2s) were cloned and expressed in Escherichia coli strain WC3110 (ΔarsC) for the first time. The abilities of both CrACR2s genes to complement the arsenatesensitive strain were examined. CrACR2.1 restored arsenate resistance at 0.8 mmol/L. However, CrACR2.2 showed much less ability to complement. The gene products were demonstrated to reduce arsenate to arsenite in vivo. In agreement with the complementation results, CrACR2.1 showed higher reduction ability than CrACR2.2, when treated with 0.4 mmol/L arsenate for 16 hr incubation.     

禽畜粪便减量化处理技术初探

随着中国养殖业的迅速发展,禽畜粪便的排放数量逐年增加。据统计,禽畜粪尿排放量每头牛为55kg/d~65 kg/d,每头猪为3.5 kg/d~11.0 kg/d,每只鸡为0.10 kg/d~0.15 kg/d,每只羊为2.66 kg/d。大量的禽畜粪便不经处理而排入环境,将会对地表水、地下水、土壤和空气造成严重的污染,并危及禽畜本身及人体健康。因此,实现禽畜粪便的减量化、无害化及资源化,防止和消除养殖场粪便的污染及其利用问题的研究,对于生态环境的保护、实施可持续发展战略都具有十分重要的意义。本试验利用日本JST赠送的生态厕所反应装置为试验设备,分别以木屑和木屑与秸秆混合物为微生物载体,对牛粪便进行减量化处理技术研究。旨在为研究中国农业的玉米作物秸秆是否可以替代木屑作为反应过程中的调理剂,达到对禽畜养殖业粪便良好的减量化处理效果,减轻对环境的污染,同时也为中国大量的农作物秸秆寻找另一条资源化利用途径。     

Thermal cracking of waste printed wiring boards for mechanical recycling by using residual steam preprocessing

Mechanical waste-processing methods, which combine crushing and separation processes for the recovery of valuable materials, have been widely applied in waste printed wiring board (PWB) treatment. However, both the high impact toughness and the tensile and flexural strengths of whole PWB with a laminated structure result in great energy consumption and severe abrasion of the cutters during multi-level crushing. In addition, the high temperatures occurring in continual crushing probably cause the decomposition of the polymer matrix. A thermal-crack method using residual steam as the heating medium has been developed to pre-treat waste PWBs. This treatment reduces the mechanical strength in order to improve the recovery rate of valuable materials in subsequent mechanical recycling. The changes of the PWBs’ macro-mechanical properties were studied to evaluate thermal expansion impacts associated with changes in temperature, and the dynamic dislocation micro-structures were observed to identify the fracture mechanism. The results showed that thermal cracking with steam at the temperature of 500 K can effectively attenuate the mechanical properties of waste PWBs, by reducing the impact, tensile and flexural strengths respectively, by 59.2%, 49.3% and 51.4%, compared to untreated PWB. Thermal expansion can also facilitate the separation of copper from glass fiber by reducing peel resistance by 95.4% at 500 K. It was revealed that the flexural fracture was a transverse cracking caused by concentrated stress when the heating temperature was less than 500 K, and shifted to a vertical cracking after exceeding 500 K.     

不同进水方式对于EPBR系统厌氧释磷的影响

为了提高实际污水处理工艺中除磷效率,优化系统中厌氧释磷的条件,主要研究了三种不同原水投加方式对厌氧释磷过程的影响。本试验采用UniFed SBR系统内的活性污泥,考察了实际生活污水对活性污泥的释磷影响,采用1次进水、4次进水和连续进水3种不同原水供给方式对于厌氧释磷性能进行比较。研究结果表明,不同进水方式可有效延长实际生活污水的注入时间,大大提高其中有机底物的可利用性,释磷速率由0.082增至0.143 mg/(L.min),其中单位活性污泥释磷量分别为2.24×10-3、3.26×10-3和3.80×10-3mg/mg,这种碳源投加方式的改变,使得利用实际生活污水的厌氧释磷特性得到优化,并提高了实际生活污水中有机碳源的可利用性和除磷效率。     

高温厌氧颗粒污泥对活性染料的吸附、解吸特性研究

试验考察高温(55℃)厌氧颗粒污泥对活性染料(以活性艳红X-3B(RR2)为代表)的吸附、解吸特征。试验结果表明,高温厌氧颗粒污泥的RR2染料吸附和解吸均符合Freundlich等温式,部分RR2被不可逆吸附;温度和盐度对高温厌氧颗粒污泥的吸附作用均有影响。     

天津滨海盐碱湿地土壤种子库特征研究

对天津滨海新区典型盐碱湿地土壤种子库进行了研究。通过选取三个标准样地进行野外调查,采用种子萌发实验确定土壤种子库的活性、种类及数量;对土壤种子库的物种组成和数量、物种多样性指数、相似性指数及时空分布等特征进行分析,结果表明,滨海新区盐碱湿地土壤种子库共有26植物,种子库的密度在6809～30644粒/m2之间;种子库的生态优势度在0.51～0.81之间,多样性指数相对较低,其中Shannon-Wiener指数最高为1.78;土壤种子库与地面植被之间的相似性指数较低,最低为0.21;种子库的垂直分布特征较为明显,其中0～5cm层种子数量最多,种子数量层间差异显著或极显著;此外,还研究了土壤种子库萌发随时间变化的规律,得出其萌发数量随时间变化的曲线,为今后土壤种子库应用于植被恢复提供了参考。     

黑龙江省农业生态环境现状分析

根据指数计算分级方法,依据农业生态环境特点,建立指标体系。根据黑龙江省现状算出其农业生态环境质量指数,再进行指标等级评价分析。用定量方法了解黑龙江省农业生态环境现状。分析农业生态环境问题,提出解决措施,改善农业生态环境,保证黑龙江省农业可持续性发展。