北偏西大风对北京冬季生物气溶胶的影响

生物气溶胶对大气成云过程、生态系统演化和人体健康都有着重要的影响,目前对生物气溶胶浓度、组成和活性的变化规律认识不足.因此,在2013年1月和2015年1月在北京市清华大学校园内进行了采样和观测,以分析气象条件对生物气溶胶浓度和组成的影响.生物气溶胶浓度用生物气溶胶在线检测器WIBS-4A(waveband integrated bioaerosol sensor)测定,生物气溶胶中细菌群落的组成用16S rDNA测序的方法来测定.结果表明,北京冬季生物气溶胶数浓度范围在2~150 L~(-1).风是影响生物气溶胶的浓度和组成的重要因素.主导风向为北偏西30°,风速大于4 m·s-1的大风天气时,生物气溶胶的数浓度升高1个数量级,生物气溶胶中细菌群落的组成也发生急剧的变化.大风天气过后,生物气溶胶中细菌群落的组成缓慢恢复到大风前的状态.     

农药综合废水处理技术

农药厂家的综合废水通过选择合理的工艺路线 ,提高废水的可生化性 ,经过二级生化处理后的出水经絮凝沉降后达标排放。     

Process evaluation of an alternating aerobic-anoxic process applied in a sequencing batch reactor for nitrogen removal

In order to improve the nitrogen removal efficiency and save operational cost, the feasibility of the alternating aerobic-anoxic process (AAA process) applied in a sequencing batch reactor (SBR) system for nitrogen removal was investigated. Under sufficient influent alkalinity, the AAA process did not have an advantage over one aerobicanoxic (OAA) cycle on treatment efficiency because microorganisms had an adaptive stage at the alternating aerobic-anoxic transition, which would prolong the total cycling time. On the contrary, the AAA process made the system control more complicated. Under deficient influent alkalinity, when compared to OAA, the AAA process improved treatment efficiency and effluent quality with NH₄ ⁺-N in the effluent below the detection limit. In the nitrification, the average stoichiometric ratio between alkalinity consumption and ammonia oxidation is calculated to be 7.07 mg CaCO₃/mg NH₄ ⁺-N. In the denitrification, the average stoichiometric ratio between alkalinity production and NO₃ ⁻-N reduction is about 3.57 mg CaCO₃/mg NO₃ ⁻-N. As a result, half of the alkalinity previously consumed during the aerobic nitrification was recovered during the subsequent anoxic denitrification period. That was why the higher treatment efficiency in the AAA process was achieved without the supplement of bicarbonate alkalinity. If the lack of alkalinity in the influent was less than 1/3 of that needed, there is no need for external alkalinity addition and treatment efficiency was the same as that under sufficient influent alkalinity. Even if the lack of alkalinity in the influent was more than 1/3 of that needed, the AAA process was an optimal strategy because it reduced the external alkalinity addition and saved on operational cost. Translated from Acta Scientiae Circumstantiae, 2004, 24(4): 576–580 [译自: 环境科学学报]     

序批式生物膜法的脱氮特性及机理研究

对序批式生物膜法工艺中所表现出来的脱氮特性进行了探讨，并提出了过量储存－SND脱氮作用机理。厌氧段脱氮主要靠生物膜对含碳氮有机物的过量储存作用；好氧段脱氮主要靠生物膜的SND作用，反硝化的有机碳源主要为生物膜中在厌氧段过量储存的有机碳源。     

The amplification refractory mutation system (ARMS): A rapid and direct prenatal diagnostic technique for β-thalassaemia in Singapore

β-Thalassaemia major patients have chronic anaemia and since 3–4 per cent of Singaporeans carry the β-gene, prenatal diagnosis is essential. We evaluated the amplification refractory mutation system (ARMS) technique as a routine test for prenatal diagnosis of β-major. Six mutations along the β-gene were studied—41–42 (-TCTT), IVSII #654 (C-T), 17β (A-T), – 28 TATA (A-G), IVSI #5 (G-C), and IVSI #1 (G-T). Our results indicate that prenatal diagnosis using these mutations can be offered to 90 per cent (35/39) of our Chinese couples and 54·6 per cent (12/22) of our Malay couples at risk. Confirmation of ARMS results was carried out using allele-specific oligonucleotide hybridization. Prenatal diagnosis using ARMS was successfully carried out in nine cases which included a set of triplets and twins. The triplets were diagnosed with the β-trait carrying the 41–42 mutation. The couple with twins possessed the #654 mutation and one twin was diagnosed with the β-trait and the other with #654 homozygosity. Genomic sequencing of the undefined mutations in the Chinese couples revealed rarer mutations at − 29 and an ATG-AGG base substitution at the initiation codon for translation. In the Malay couples, genomic sequencing detected mutations at codon 15 (TGG-TAG) and codon 26 (GAG-AAG). We conclude that ARMS with its direct detection of amplified products by gel electrophoresis provides an accurate, rapid, and simpler method for our β-thalassaemia prenatal diagnosis programme in Singapore.     

水解酸化-序批式活性污泥法处理季戊四醇有机废水

在实验室研究的基础上 ,将水解酸化 序批式活性污泥 (HA SBR)处理工艺应用于季戊四醇生产废水治理工程中 ,运行结果表明 :CODCr去除率在 90 %以上 ,BOD5去除率在 85 %以上 ,所排废水各项指标达到国家排放标准。     

硝基苯降解菌在厌氧序批式反应器中处理硝基苯废水的应用

通过接种硝基苯降解菌于厌氧序批式反应器（ASBR），研究静态试验条件下和厌氧序批式工艺对硝基苯的降解规律，研究表明，应用生物强化技术处理硝基苯废水，具有很高的处理效率。     

利用混合菌群活性污泥法实现生物可降解塑料PHA的合成

PHA是一种生物可降解塑料，可从污水有机物中合成。文章在简要说明现阶段工业生产PHA情况的基础上，总结了利用混合菌种活性污泥法从污水有机物中合成PHA的优点。重点对两种从污水中生产PHA工艺——厌氧-好氧活性污泥工艺和好氧瞬时供料工艺进行了介绍，并给出了相应工艺流程。通过使用廉价的有机底物可以使PHA的生产价格降低到原来的一半，大约为每公斤4欧元左右。文章还讨论了控制工艺运行条件对PHA合成的重要性，并说明了不同底物组成对合成PHA性质的影响。     

ASBR处理热水解污泥的启动试验研究

进行了中温、高温厌氧序批式反应器(ASBR)处理热水解污泥的启动试验,同时与中温连续流搅拌反应器(CSTR)进行对比,ASBR 启动期包括种泥驯化期、过渡期和稳态期 3 个阶段.启动过程中污泥固体物质在 ASBR 中不断积累而保持较高的固体停留时间(SRT),有助于提高处理效率.污泥中蛋白质生化降解产生的氨氮提高了体系的缓冲能力,pH值保持在 6.60~7.72之间.当水力停留时间(HRT)为 20d、容积负荷为 2.71kg COD/(m3d) 时,中温 ASBR、高温 ASBR 和中温 CSTR 的总 COD(TCOD)去除率分别为 67.71%、64.55%、60.25%.相应地, ·中温、高温 ASBR 的平均日产气量比中温 CSTR 分别提高 15%、10%.     

水解酸化-序批式活性污泥法(ABR-SBR)处理电泳废水的研究

利用水解酸化 (采用缺氧折流板ABR反应器 ) -序批式活性污泥法 (SBR)工艺对汽车电泳涂装工艺废水进行实验研究 ,分析了ABR的反应时间、容积负荷、内置填料对废水可生化性改善的影响及SBR的运行方式、进水 pH、污泥负荷对有机物去除效果的影响