Available Water Supplies in Beijing,China, Under Single‐ and Multi‐Year Drought

Since its implementation in 2015, the Middle Route of the South‐to‐North Water Diversion Project (MR‐SNWDP) has transferred an average of 45 billion cubic meters of surface water per year from the Yangtze River in southern China to the Yellow River and Hai River Basin in northern China, but how that supply is able to cope with droughts under different scenarios has not been explored. In this study, using the water demand for 2020 as the guaranteed water target, a Water Evaluation and Planning system was used to simulate available water supplies in Beijing under different drought scenarios. In the case of a single‐year drought, without the MR‐SNWDP, Beijing’s water shortage ratio was 16.7%; with the MR‐SNWDP, this ratio reduced to 7.3%. In the case of a multi‐year drought, without the MR‐SNWDP, Beijing’s water shortage ratio was 25.3%; with the MR‐SNWDP, this ratio reduced to 7.4% and domestic water supply was improved. Our research suggests that to prepare for multi‐year drought in the Beijing area, the SNWDP supports increased supplies to the region that would mitigate drought effects. This study is, however, mostly focused on water supply provision to Beijing and does not comprehensively evaluate other potential impacts. Multiple additional avenues could be pursued that include replenishing groundwater, increasing reservoir storage, and water conservation methods. Further research is needed to explore the relative costs and benefits of these approaches.     

北京市垃圾填埋气体排放模拟及CDM现状分析

为了理清北京固废系统潜在的环境影响及相关机制发展状况,本研究基于填埋气逸出模拟对北京市固废系统中的填埋气排放和CDM项目进行研究分析。将中国垃圾填埋气模型应用到北京市,预测其潜在垃圾填埋气排放总碳当量达0.97亿t,2026年左右迎来产气高峰,排放量为54 367 m3/h,碳当量达228万t,2015—2040年间的碳当量占比约53.3%;北京市CDM数据分析显示,2010年以来北京市CDM项目发展良好,但较全国水平稍显滞后,其垃圾填埋气回收利用项目占北京市获批CDM项目总量的11.1%,签发数比例约33.3%,远低于全国水平的41.82%。研究表明:北京市固废系统即将步入产气高峰期,潜在碳排放量巨大,势必将给北京市的温室气体减排工作带来切实压力,但是相关CDM项目发展不适应当前的减排需求,急需加强和改善北京市的城市固体废物管理,推进相关CDM项目在北京的良性发展。     

近二千年中国重大气象灾害气候变化背景初步分析

以不同分辨率建立了近二千年和近五百年中国重大气象灾害频率分布曲线。得出近二千年我国重大气象灾害频率分布，在１１世纪前低处于低发时期，１１～１２世纪灾害迅速增加，以后通过两峰两谷于１９世纪进入灾害群发时期。近五百年，１７世纪和１９世纪中叶后为两个灾害群发时期。上述灾害群发时期都发生在数百年气候变化暖的背景下的暖期和冷的背景下的冷期。另外在气候转折时期，我国重大气象灾害也群发。根据上述关系，估计现今至２０３０～２０５０年，具有灾害群的气候变化背景，我国重大气象灾害将群发，特别是洪涝与风暴潮增加，同时由于人类活动加剧，水资源开发力度加大，对于大面积干旱也不可忽视。     

防冲吸能构件应变特性及巷道支架应用研究*

为明确防冲吸能支护的力学特性及其应用效果,基于竖向准静态压缩试验研究防冲吸能构件的荷载位移曲线,采用ABAQUS模拟防冲吸能构件的变形压溃过程,并与试验结果进行对比,对变形过程中构件管壁的应变演化进行分析,进而研究吸能支架在冲击作用下的应变特性。研究结果表明:数值计算可以较好地对防冲吸能构件的变形吸能过程和荷载位移曲线进行模拟;采用该构件的液压支架能够满足防冲吸能支护的设计理念和原则;对吸能支架吸能特性研究,防冲吸能构件能够在冲击来临时更好地保护支架,研究成果可为冲击地压巷道支护体系提供设计参考。     

Preliminary evaluation of evaluation of the efficiency of aircraft liquid waste treatment using resolvable sanitizing liquid: a case study in Changchun

The physical, chemical, and biological indices of aircraft liquid wastes collected from multiple airplanes at Longjia Airport, Changchun, China were measured according to "Integrated Wastewater Discharge Standard," evaluating treatment efficiency of resolvable sanitizing liquid. The results indicate that, after being treated by the resolvable sanitizing liquid, the indices of all first-class pollutants met the requirements of the standard, while among the second-class pollutants, the suspension content, biochemical oxygen demand after 5 days, and chemical oxygen demand as well as the contents of amino nitrogen, total phosphorus, anionic surfactants, total copper, absorbable organic halogen, and phenolic compounds did not reach the discharge standard. Particularly, the level of fecal coliform bacteria in the aircraft liquid wastes can meet the standard specification by adding more than 1 mL/L resolvable sanitizing liquid. The aircraft wastewater treated by resolvable sanitizing liquid cannot be directly discharged back into the environment as well as urban drainage systems.     

北京斋堂黄土剖面主要温室气体组分初步研究

全球碳循环研究表明．在北半球中纬度地带可能存在一个陆地生志汇（植被和土壤）。中国黄土分布在北半球中纬度，在CO2未知汇的研究中很可能具有重要作用。通过自制钻机对北京斋堂黄土剖面（L2上部～L1）进行了不同层位（深度）的垂直或水平打钻，利用毛细管负压原理采集到游离气体并进行了主要温室气体CP2、CH4、N2O的浓度和CO2的碳、氧同位素组成分析。此外，还分析了土样的碳酸盐含量及其碳、氧同位素组成。初步研究结果表明，黄土剖面中主要温室气体浓度远比大气中高：CO2浓度为1434．4×10－6～2458．6×10－6，是大气中的3．8～6．5倍；N2O浓度为472．2×10－9～763．9×10－9，是大气中的1．3～2．1倍；CH4浓度在剖面上部与大气中相似，但在下部为13．1×10－6～24．8×10-6，为大气中的5．4～10．2倍。斋堂黄土剖面中的破酸盐含量为1．55％～9．75％，CO2浓度与碳酸盐含量成正比关系。尽管黄土－古土壤序列富含碳酸盐，但需进一步开展黄土中的CO2浓度及碳同位素工作，以便了解黄土中CO2在全球碳循环中的地位和作用。     

选择性复合电极的制备及其对硝酸盐的去除性能

以IRA 402强碱性阴离子交换树脂为原料,通过静电纺丝技术制备对硝酸盐具有选择去除性能的薄膜(nitrate selective removal membrane,NSRM),采用扫描电镜、傅里叶红外、Zeta电位分析仪等仪器对其进行分析和表征,考察了纺丝时间、操作电压、循环流速、硝酸盐初始浓度和共存离子等因素对NO₃⁻去除性能的影响。表征结果表明,NSRM膜表面粗糙多孔且带正电,薄膜上C≡N、C(O)NH、N—H等基团的存在促进NO₃⁻的优先吸附。电吸附结果表明,纺丝时间3 h制得的NSRM膜对NO₃⁻去除率最优,在初始质量浓度为50 mg·L⁻¹,操作电压为2.0 V,循环流速为100 mL·min⁻¹时硝酸盐去除率达88.17%。多离子混合条件下,NSRM薄膜对F^-、Cl^-有较好的选择性,对SO₄²⁻有一定选择性,对PO₄^3-选择性不佳,其中,当NO₃⁻与F⁻、Cl⁻物质量浓度比值为1：1时,NO₃⁻的选择性分别为4.23和2.09。     

碳氮比对高盐废水单室MFCs产电、污染物去除及微生物群落结构的影响

构建了 5套单室无膜空气阴极微生物燃料电池(microbial fuel cell,MFC),探讨了碳氮比对单室MFC产电及污染物去除效果的影响,并通过微生物高通量测序分析了电极生物膜的优势菌种.结果表明:当碳氮比分别是3∶1、4∶1、5∶1、6∶1和7∶1时,在产电性能方面,碳氮比的提高有利于电池电能的输出;当碳氮比...     

乌海市臭氧传输特征与潜在源区

乌海是典型的西北工业城市,O3污染问题突出但缺乏研究.本文基于乌海市环境监测数据、气象数据分析了乌海市O3污染特征.结果 表明:乌海市O3日最大8h平均值(MDA8O3)第90位百分数由2015年的131 μg·m-3上升至2018年的162 μg·m-3,超标天数由2015年的8d上升到2018年的44 d,O3超标...     

长江口近十年上覆水Pb浓度演变特征分析

为了解长江口南北支上覆水中溶解态重金属的演变特征,运用Mann-Kendall法和R/S分析法分析了徐六泾水域、青龙港水域、启东港水域、东风西沙水源区、石洞口水域、南港水域、北港水域等7个水域中溶解态Pb浓度近十年来的变化并对未来的变化趋势进行预测,结果表明:7个水域Pb年平均浓度均在0.15mg/L以下,均达到了Ⅱ类水标准指标;除启东港和青龙港水域Pb浓度较高外,其余5个水域上覆水中Pb浓度均处于较低水平,且变化幅度较小;7个水域的Pb浓度总体都呈轻微下降趋势;Pb浓度演变与工业废水排放等因素有关。