二氧化碳回收技术进展

CO2的过量排放对全球的气候变暖有着不可推卸的责任,同时CO2又是一种重要的碳资源,对它的回收和利用将具有很大的经济效益和社会效益。CO2回收的方法主要是膜吸收法、变压吸附法、化学吸收法和低温分离法,特别是离子液体对CO2的吸收,为CO2的减排提供了良好的手段。     

两性高分子螯合絮凝剂的合成及作用机理

合成了一种两性高分子螯合絮凝剂(ACPF),采用元素分析、IR光谱和紫外光谱对其结构进行表征.考察了其对含Ni2+废水的处理效果,测定了微絮体的ξ电位,通过扫描电镜和电子能谱考察了絮体的形貌和组成,初步探讨了螯合絮凝作用机理.结果表明,当ACPF中--CSS-与Ni2+的物质的量之比接近2:1时,对Ni2+的去除率大于...     

膜生物反应器（MBR）处理垃圾渗滤液的脱氮研究

采用一体式MBR处理垃圾渗滤液,系统考察MBR对COD、NH4＋-N和TN的去除效果。结果表明：可将垃圾渗滤液的COD降至650-1 500 mg·L-1范围;在HRT为1.5 d、DO为0.75-1.20 mg·L-1、不排泥条件下运行时,对TN质量浓度低于2 300 mg·L-1、容积负荷低于0.25 kg.m-3.d-1（以N计）的渗滤液进行处理,MBR对NH4＋-N与TN的去除率可分别达到87%和72%以上。在MBR处理垃圾渗滤液的运行中发现,膜的污染速度较快,并且呈现＂两段性＂的规律,采用碱＋氧化剂的清洗方式可有效去除膜污染,降低过膜压力。     

成品油库含油污水处理问题与对策

介绍了成品油库含油污水的排放特点,分析了现有工艺单元和处理流程存在的问题,并对成品油库含油污水处理设施的设计、选型、维护和运行提出了建议。     

农业气候资源变化对双季稻生产的可能影响分析

基于长江中游地区50 个气象台站自1960 年以来的历年地面气象观测资料,分1960-2009 及1960-1984、1985-2009 年3 个不同时间段,分温度生长期、早稻生长期、晚稻生长期分别分析了热量、光照、降水等农业的变化特征,并讨论对双季稻生产的可能影响。1960-2009年,该地区温度生长期平均气温、平均日最低气温、平均日最高气温的平均增速分别为0.08 ℃/10 a、0.09 ℃/10 a、0.07 ℃/10 a,≥10 ℃活动积温的平均增速为66.3 ℃/10 a,日照时数的平均减速为31.7 h/10 a,降水量的平均增速为3.7 mm/10 a。表现为温度上升、积温增加、温度生长期延长、日照时数减少、降水量微弱增加的变化特征。温度升高、积温增加可能导致发育速度加快、生育期缩短、病虫害加重,日照时数减少可能影响叶片光合及产量。早稻生长期的平均气温、≥10 ℃活动积温的增速分别为0.20 ℃/10 a、48.9 ℃/10 a,晚稻生长期分别为0.09 ℃/10 a、14.6 ℃/10 a,早稻和晚稻生长期间日照时数的下降速率分别为18.6 h/10 a、42.7 h/10 a,降水量的增加速率分别为1.9 mm/10 a、8.7 mm/10 a,表现为升温速率早稻大于晚稻,日照时数下降速率晚稻大于早稻,降水量增加速率晚稻大于早稻。早稻期间升温和积温增加明显可能有利于早稻提前播种、选用生育期稍长的品种、提高产量潜力和产量,晚稻期间升温不明显且日照时数下降则可能不利于群体光合和产量形成,影响其产量潜力和产量。区域中的江汉平原、洞庭湖平原等基础条件好的地区,其热量、日照、降水同步增加,其他地区则表现为热量、降水增加,但日照时数下降,要充分发挥其基础条件好与气候资源丰富且同步增加等优势,发展高效规模化生产,增强稻谷生产能力。     

基于后向轨迹对城市大气中二噁英长距离迁移来源的探讨

通过对广州某商住区大气中二噁英的季节性监测,结合后向轨迹的计算,对大气中PCDD/Fs的浓度及其长距离迁移来源进行分析.结果表明:大气中二噁英浓度有季节性变化特点,其趋势为冬季(14.4 pg·m^-3)>秋季(10.0 pg·m^-3)>春季(5.54 pg·m^-3)>夏季(3.88 pg·m^-3).同时,大气中PCDD/Fs单体特征也具有季节性特点,秋冬季节七氯代、八氯代PCDD/Fs百分比高于春秋两季,春夏两季低氯代单体百分比含量高于秋冬两季.追溯采样期间该城市大气的后向轨迹,发现秋冬两季到达广州的气团主要经过湖南、湖北和江西等北方或东北方的内陆省份,而春夏两季到达广州的气团主要经过我国东海和南海海域上空.而这种变化很可能是造成广州大气中二噁英浓度季节性变化的主要原因.     

砂石加工废水处理工艺研究

通过对砂石加工废水水质特性的研究可知,该类废水悬浮物浓度高、沉降性能好、且随时间推移,沉降泥渣的比阻呈增大趋势,泥渣的脱水越来越困难。在研究的基础上提出了处理该类废水的新工艺,并在中试规模将其与现行处理工艺进行了比较。结果表明,新工艺运行稳定、处理成本较低,为0.53元/吨水、泥渣脱水历时短、排泥管不易堵塞,较好地解决了废水中悬浮物沉降后泥渣的处理与排放之间的矛盾,SS去除率为99.8%,处理效果较好,可广泛应用于工程设计。     

脱硝副产物硫酸氢铵在飞灰表面沉积与演化特性

空预器堵塞常来源于脱硝副产物硫酸氢铵(ABS)与飞灰的共沉积,通过模拟空预器内温度场,探究ABS与飞灰共存条件下的沉积与演化特性,以期为空预器堵塞防治提供指导.飞灰对烟气中生成的ABS存在捕集和吸附作用,提高了ABS沉积速率与初始生成温度.在100μL/L SO₃与50μL/L NH₃条件下,ABS的初始沉积温度在240～270℃之间.高温段反应篮内无明显的ABS液滴存在,飞灰存在结块现象;低温段反应篮壁面出现少量小液滴,飞灰呈现大颗粒状.ABS沉积将导致飞灰颗粒的积聚和粘附,并在飞灰表面转化为分解温度较高的各种硫酸盐类物质.与低温段硫酸滴在飞灰上演化形成的硫酸盐相比,ABS转化形成的硫酸盐具有较低的相对分解温度.     

Preparation and evaluation of bis(diallyl alkyl tertiary ammonium salt) polymer as a promising adsorbent for phosphorus removal

Problems associated with water eutrophication due to high phosphorus concentrations and related environmentally safe solutions have attracted wide attention. A novel bis(diallyl alkyl tertiary ammonium salt) polymer, particularly poly(N~1,N~1,N~6,N~6-tetraallylhexane-1,6-diammonium dichloride)(PTAHDADC), was synthesized and characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance, scanning electron microscopy, mercury intrusion method, and thermogravimetric analysis. The adsorption characteristics in phosphorus were evaluated in dilute solution, and the recycling properties of PTAHDADC were investigated. Results showed that PTAHDADC possessed macropores with a size distribution ranging from 30 to 130 μm concentrating at 63 μm in diameter and had 46.52% of porosity, excellent thermal stability below 530 K, and insolubility. PTAHDADC could effectively remove phosphorus at p H = 7–11 and had a removal efficiency exceeding 98.4% at pH = 10–11. The adsorption equilibrium data of PTAHDADC for phosphorus accorded well with the Langmuir and pseudo-second-order kinetic models. Maximum adsorption capacity was 52.82 mg/g at 293 K. PTAHDADC adsorbed phosphorus rapidly and reached equilibrium within 90 min. Calculated activation energy Eawas 15.18 k J/mol. PTAHDADC presented an excellent recyclability with only 8.23% loss of removal efficiency after five adsorption–desorption cycles. The morphology and structure of PTAHDADC slightly changed as evidenced by the pre-and post-adsorption of phosphorus, but the process was accompanied by the partial deprotonation of the(–CH_2)_3-NH~+ group of PTAHDADC. The adsorption was a spontaneous exothermic process driven by entropy through physisorption, electrostatic attraction, and ion exchange. Survey results showed that PTAHDADC was a highly efficient and fast-adsorbing phosphorus-removal material prospective in treating wastewater.     

Roles of Scholars in the Practice of Combating-Desertification: A Case Study in Northwest China

This study investigated the perceived importance of scholars’ participation in combating-desertification programs in northwest China and analyzed the underlying factors and mechanisms. Our results show that, while various experts, professors, and researchers have participated in combating-desertification programs, their actions were often not effective. Only those scholars who understood the local situations adequately had important and positive impacts. These scholars served as information brokers between the governments and other stakeholders, entrepreneurial activity organizers for farmers, governmental representatives, or advocators for local affairs themselves. They played indispensible roles in facilitating efforts in combating desertification. The study also identified key factors that led to the success of scholars’ participation in combating-desertification activities. Our findings have practical implications for improving the effectiveness of scholars’ participation in land restoration and environmental management.