两性磁化炭添加比例对河流沿岸土吸附Cu2+的影响

将两性(十二烷基二甲基甜菜碱)修饰磁化炭分别以质量分数0、1%和2%加入嘉陵江流域(川渝段)内苍溪(CX)、南部(NB)、嘉陵(JL)和合川(HC)沿岸土中,考察各混合土样对Cu^2+的等温吸附和热力学特征。结果表明:混合土样对Cu^2+的最大吸附量为58.36 mmol/kg~366.85 mmol/kg,添加等量两性磁化炭时各混合土样对Cu^2+吸附量表现为JL>NB>CX>HC的趋势,且添加比越高吸附能力越强。各混合土样对Cu^2+的吸附为自发、吸热和熵增的反应过程,对Cu^2+的吸附量与温度和pH值均呈正相关关系。当离子强度为0.1 mol/L时,各混合土样(除HC外)对Cu^2+的吸附量最大。     

Spatial analysis of resources and environmental carrying capacity in Iran

Urbanization and mass movement of the population from rural areas and small cities to megacities have led to environmental, economic, and social problems in Iran. In dealing with these challenges, assessing resource and environmental carrying capacity (RECC) is considered an effective method to leverage space and capital to achieve sustainable development. This study aimed to rank the provincial RECC in Iran. Toward this purpose, environmental indices were generated from remotely sensed and statistical census data. Then, the provinces were scored in terms of environmental, economic, and infrastructural carrying capacities, and RECC using the mean variance analysis method. Results demonstrated that in most areas, there is no relationship between economic and infrastructural capacities and development. Statistically, a correlation coefficient of −0.53 between economic and environmental carrying capacities indicated excessive use of environmental capacities. Moreover, the spatial distribution pattern of environmental, economic, and infrastructural carrying capacity was entirely heterogeneous between the provinces; there was a northeast–southwest pattern in terms of infrastructural capacity and an economic pattern from north to south. The distribution pattern of RECC is most consistent with the environmental capacity, pointing at the high weight of the indicators of the RECC model. In conclusion, this research offers a new vision for policymakers and provides a theoretical and applicable framework for implementing sustainable strategies in land-use planning. It is recommended that the RECC concept and tools can be used not only for planning but also for measuring the efficiency of spatial development programs and establishing land balances in the region.     

Efficient removal of Cr(VI) by a 3D Z-scheme TiO2-ZnxCd1-xS graphene aerogel via synergy of adsorption and photocatalysis under visible light

Efficient and robust photocatalysts for environmental pollutants removal with outstanding stability have great significance. Herein, we report a kind of three dimensional (3D) photocatalyst presented as Z-scheme heterojunction, which combining TiO 2 and Zn x Cd 1- x S with graphene aerogel to contrast TiO 2 -Zn x Cd 1- x S graphene aerogel (TSGA, x = 0.5) through a moderate hydrothermal process. The as-prepared Z-scheme TSGA was used to remove aqueous Cr(VI) via a synergistic effect of adsorption and visible light photocatalysis. The adsorption equilibrium can be reached about 40 min, then after about 30 min irradiation under visible light (wavelength ( λ) > 420 nm) the removal rate of Cr(VI) almost reached 100%, which is much better than the performance of pristine TiO 2 and Zn 0.5 Cd 0.5 S, as well as TiO 2 graphene aerogel (TGA) and Zn 0.5 Cd 0.5 S graphene aerogel (SGA). The virulent Cr(VI) was reduced to Cr(III) with hypotoxicity after photocatalysis on TSGA, meanwhile the as-synthesized TSGA presented a good stability and reusability. The reduced graphene oxide (rGO) sheets between TiO 2 and Zn 0.5 Cd 0.5 S played a role as charge transfer mediator, promoting the photoinduced electrons transfer and photocatalysis ability of TSGA was enhanced significantly. Hence,such photocatalyst exhibits a potential application on removing heavy metals with high efficiency and stability from polluted aqueous environment.     

渤海湾入海溶解无机氮总量控制研究

基于渤海湾近岸海域的实际调查结果,采取生态物理耦合模型,对渤海湾的主要污染物-溶解无机氮(DIN)的基准环境容量和极小剩余海洋环境容量进行了计算。结果表明,渤海湾DIN的极小剩余海洋环境容量在Ⅰ类和Ⅱ类水质标准下均为负值,渤海湾的DIN已经超标。结合实际的海水功能区水质管理目标,应重点控制非点源的排放,加强上游携带入境污染物的处理,从总量上控制DIN入海污染通量,改善渤海湾水质。     

某电厂600MW火电机组脱硫增容改造方案探讨

按照国家环保部文件要求，大唐集团河北某电厂600 MW机组湿法脱硫系统需进行增容改造。该电厂根据实际情况，归纳了3种可行的脱硫增容改造方案，即原吸收塔增加喷淋层和高度、双吸收塔串联、双吸收塔双循环，阐述了各自的技术特点，结合性能保证、工程投资、施工周期等影响因素，比较了各方案的优缺点。经过对比和论证，双吸收塔方案比单吸收塔方案更适合于本次工程改造。     

A strategy for the next decade to address data deficiency in neglected biodiversity

Measuring progress toward international biodiversity targets requires robust information on the conservation status of species, which the International Union for Conservation of Nature (IUCN) Red List of Threatened Species provides. However, data and capacity are lacking for most hyperdiverse groups, such as invertebrates, plants, and fungi, particularly in megadiverse or high-endemism regions. Conservation policies and biodiversity strategies aimed at halting biodiversity loss by 2020 need to be adapted to tackle these information shortfalls after 2020. We devised an 8-point strategy to close existing data gaps by reviving explorative field research on the distribution, abundance, and ecology of species; linking taxonomic research more closely with conservation; improving global biodiversity databases by making the submission of spatially explicit data mandatory for scientific publications; developing a global spatial database on threats to biodiversity to facilitate IUCN Red List assessments; automating preassessments by integrating distribution data and spatial threat data; building capacity in taxonomy, ecology, and biodiversity monitoring in countries with high species richness or endemism; creating species monitoring programs for lesser-known taxa; and developing sufficient funding mechanisms to reduce reliance on voluntary efforts. Implementing these strategies in the post-2020 biodiversity framework will help to overcome the lack of capacity and data regarding the conservation status of biodiversity. This will require a collaborative effort among scientists, policy makers, and conservation practitioners.     

Mg3MnxAl1-xCO3类水滑石衍生NSR催化剂的制备及其性能评价

采用共沉淀法合成了三元类水滑石Mg_3Mn_xAl_(1-x)CO_3,通过高温煅烧得到其衍生氧化物Mg_3Mn_xAl_(1-x)O_m,再经浸渍负载Pt或BaO后制得新型NO_x存储/再还原(NSR)催化剂。XRD及SEM表征结果显示,当Mn与Al的摩尔比(Mn/Al)大于1时所制备的Mg_3Mn_xAl_(1-x)O_m有杂晶相出现且发生团聚,结合NO_x存储性能评价结果,确定最优Mn/Al为1。BaO负载不利于NO_x的存储,而当Pt负载量为1%(w)时NO_x存储性能最优,250℃条件下的存储量由负载前的0.52 mmol/g提升至0.61 mmol/g。CO_2与NO_x之间存在较强的竞争吸附。负载1%Pt催化剂的NSR性能评价结果表明,8个稀燃-富燃循环后NO_x的去除率为68%,表明催化剂的还原性能仍需加强。     

长庆油田4731B型非金属集输管道老化特性实验研究

为推广非金属复合管在油田集输油领域的应用，明确其在集输环境中的老化特性是关键问题。基于集输油现场的工程条件，针对长庆油田试用的4731B型钢丝缠绕增强复合管，以采出原油、采出水为实验介质，通过挂片实验、水压爆破实验，借助电镜扫描、拉伸测试对复合管内衬层老化行为、拉伸性能以及复合管极限承压与老化特性进行研究。结果表明:采出原油与采出水均可渗透扩散进入内衬层内部，还会发生局部深入渗透；采出原油、采出水的局部渗透速率分别可达3.4，10.6 mm/a；在某些工况下，内衬层表面产生裂纹；短时间（168 h）内的介质渗透甚至裂纹对其机械性能影响较小，而光氧老化影响显著；现场服役813 d后，复合管极限承压下降2.79%，表明复合管承压性能稳定。     

新型生物质活性炭烟气脱硫研究

以农业废弃物核桃壳为原料,天然软锰矿为添加剂共混制备得到的新型生物质柱状活性炭进行烟气脱硫的性能研究.采用固定床反应器进行脱硫实验,装填活性炭质量为16 g,考察了进口SO2含量、空速、床层温度、水蒸气和氧气含量等工艺参数对活性炭脱硫性能的影响.结果表明,进口SO2含量在0.1%～0.3%(体积含量)范围内时,活性炭的穿透硫容和穿透时间随着进口SO2含量的升高而降低;空速越大,活性炭越容易穿透,较佳的空速为600 h-1;最适的床层温度为80℃,过高会降低脱硫效率;水蒸气和氧气的存在大大促进了活性炭对SO2的吸附性能,最佳水蒸气含量为10%,最佳氧气含量为10%～13%.在最佳工艺操作条件下,当进口SO2含量为0.2%时,活性炭穿透硫容为252 mg.g-1,穿透时间可达26 h.     

Lindet ypeF(K)沸石对Zn~(2+)的吸附研究

利用粉煤灰合成Linde type F(K)沸石吸附重金属Zn2+,考察吸附剂量、pH值、反应温度对Zn 2+吸附效果影响,研究沸石吸附Zn2+的等温线与动力学,得到了相应的模型。结果表明:吸附剂量、pH值、反应温度均对Zn2+去除效果影响显著。随着吸附剂量增大,Zn 2+去除效果不断提高,饱和吸附量逐渐减小。初始pH值为3~7时,沸石对Zn2+去除率随pH值升高迅速提高。反应温度越高,沸石吸附Zn2+到达平衡时间越短。沸石对Zn2+吸附过程符合Langmuir吸附等温式,其吸附为单分子层吸附;准二级反应动力学方程能很好描述沸石对Zn2+的吸附行为。