两性聚丙烯酰胺反相乳液的制备及其脱色性能

以2-丙烯酰胺基-2-甲基丙磺酸(AMPS)和丙烯酰胺(AM)为单体,通过反相乳液聚合制备阴离子聚丙烯酰胺,再通过Mannich反应制得两性聚丙烯酰胺.将制得的两性聚丙烯酰胺产品直接用于碱性品红溶液的脱色.实验结果表明:在n(AMPS)∶n(AM) =0.2、n(多聚甲醛)∶n(阴离子聚丙烯酰胺)=0.5、溶液pH为9...     

改性淀粉的合成及其对重金属离子的捕集效果

以玉米淀粉为原料，经过交联、间接醚化、胺化以及cs：亲核加成反应，得到二硫代氨基甲酸基（DTC）改性淀粉（DTCS），并对其合成条件进行优化；考察了交联度、醚化温度、氯含量及胺化剂对DTCS捕集重金属离子效果的影响。优化后的DTCS合成条件：交联淀粉（CS）沉降积为30—34mL，醚化温度为80℃，氯质量分数为7．82％，胺化剂为二乙烯四胺。实验结果表明，DTCS对Cu^2＋，Pb^2＋，Zn^2＋，Cd^2＋，Ni^2＋均有较好的去除效果，其对Cu^2＋，Pb^2＋，Zn^2＋，Cd^2＋，Ni^2＋的饱和吸附量分别为0．85，0．83，0．65，0．74，0．47mmol／g。     

Methane production potential of leachate generated from Korean food waste recycling facilities: a lab-scale study

This paper examines the applicability of food waste leachate (FWL) in bioreactor landfills or anaerobic digesters to produce methane as a sustainable solution to the persisting leachate management problem in Korea. Taking into account the climatic conditions in Korea and FWL characteristics, the effect of key parameters, viz., temperature, alkalinity and salinity on methane yield was investigated. The monthly average moisture content and the ratio of volatile solids to total solids of the FWL were found to be 84% and 91%, respectively. The biochemical methane potential experiment under standard digestion conditions showed the methane yield of FWL to be 358 and 478 ml/g VS after 10 and 28 days of digestion, respectively, with an average methane content of 70%. Elemental analysis showed the chemical composition of FWL to be C(13.02)H(23.01)O(5.93)N(1). The highest methane yield of 403 ml/g VS was obtained at 35 degrees C due to the adaptation of seed microorganisms to mesophilic atmosphere, while methane yields at 25, 45 and 55 degrees C were 370, 351 and 275 ml/g VS, respectively, at the end of 20 days. Addition of alkalinity had a favorable effect on the methane yield. Dilution of FWL with salinity of 2g/l NaCl resulted in 561 ml CH(4)/g VS at the end of 30 days. Considering its high biodegradability (82.6%) and methane production potential, anaerobic digestion of FWL in bioreactor landfills or anaerobic digesters with a preferred control of alkalinity and salinity can be considered as a sustainable solution to the present emergent problem.     

渔阳太守张堪

侯风地动仪的发明者——东汉伟大的科学家张衡,早已广为人知。对于张衡的爷爷,很多读者却比较陌生。《后汉书·张衡传》里也只有7个字: “祖父堪,蜀郡太守。”其实,张堪在《后汉书》里也有传,记载也比较详细:张堪,字君游, 南阳郡宛县(今河南南阳市)人。父母双亡后,张堪将数百万遗产让与侄子, 16岁到长安学习儒学,品行出众,被老     

基于复杂网络的台风灾害演化系统风险分析与控制研究

基于复杂网络理论,提出了一种针对自然灾害演化系统的风险分析与控制的思路与方法。以"莫拉克"台风为例,构建了包含30个危机事件与39条连接边的台风网络演化模型;采用网络节点的出入度、子网节点数和包含节点的支链数进行风险分析,并确定关键节点,进一步提出断链方案和控制建议。结果表明:狂风、暴雨、洪水、山体滑坡、泥石流、交通堵塞和村庄毁坏等事件风险较大,是台风灾害系统的关键节点。据此提出建议:提高城市排水系统运行能力,加强交通系统监管和调度力度,启动农村人员安置和灾后重建预案。     

A hybrid fuel cell for water purification and simultaneously electricity generation

● A novel hybrid fuel cell (F-HFC) was fabricated. ● Pollutant degradation and synchronous electricity generation occurred in F-HFC. ● BiOCl-NH₄PTA photocatalyst greatly improved electron transfer and charge separation. ● Pollutant could act as substrate directly in ambient conditions without pretreatment. ● The mechanism of the F-HFC was proposed and elucidated. The development of highly efficient energy conversion technologies to extract energy from wastewater is urgently needed, especially in facing of increasing energy and environment burdens. Here, we successfully fabricated a novel hybrid fuel cell with BiOCl-NH₄PTA as photocatalyst. The polyoxometalate (NH₄PTA) act as the acceptor of photoelectrons and could retard the recombination of photogenerated electrons and holes, which lead to superior photocatalytic degradation. By utilizing BiOCl-NH₄PTA as photocatalysts and Pt/C air-cathode, we successfully constructed an electron and mass transfer enhanced photocatalytic hybrid fuel cell with flow-through field (F-HFC). In this novel fuel cell, dyes and biomass could be directly degraded and stable power output could be obtained. About 87 % of dyes could be degraded in 30 min irradiation and nearly 100 % removed within 90 min. The current density could reach up to ~267.1 μA/cm²; with maximum power density (P_max) of ~16.2 μW/cm² with Rhodamine B as organic pollutant in F-HFC. The power densities were 9.0 μW/cm², 12.2 μW/cm², and 13.9 μW/cm² when using methyl orange (MO), glucose and starch as substrates, respectively. This hybrid fuel cell with BiOCl-NH₄PTA composite fulfills the purpose of decontamination of aqueous organic pollutants and synchronous electricity generation. Moreover, the novel design cell with separated photodegradation unit and the electricity generation unit could bring potential practical application in water purification and energy recovery from wastewater.     

Piezoelectric hydrogen production from aliphatic alcohols and acids in wastewater

Environmental Chemistry Letters - The growing energy demand in the context of climate change issues requires the development of green fuels such as hydrogen from water. Piezocatalytic water...     

Longevity of organic layers of vertical flow ponds for sulfate reduction in treating mine drainages in South Korea

This study was carried out to evaluate longevity of available organic materials used for sulfate-reducing bacteria (SRB) activity in vertical flow ponds (VFPs) to treat mine drainage in South Korea. Spent mushroom compost samples (SMC) were tested as substrates in VFPs and analyzed for total organic carbon in VFPs, and were collected to analyze total organic carbon (TOC), T-N, T-P, K, metals and residual cellulose to check the longevity assessment. Chemical analysis revealed that the average contents of Fe, Al and Mn in SMC of VFPs were 19,907, 32,137 and 434 mg/kg, respectively. The contents of Fe and Al in SMC of VFPs were much higher than those of the unused SMC (control), but to the contrary, those of Mn showed a reversed tendency. Average TOC content of the controls was 64.19% but in one of the VFP substrates was as low as 15.92%. This might be resulted from SRB consumed the available organic carbon in SMC as VFPs system aged. Contents of T-N in VFPs tended to decrease as VFPs aged. The residual cellulose ranged from 3.88 to 6.72% (g/g). There existed a negative relationship between residual cellulose contents and ages of VFPs. Assuming that SMC in all VFPs had similar compositions when the VFPs were initially established, trend analysis predicted that the amount of carbon source for SRB might be available for 12-15 years further, depending on VFPs.     

云南野生牛肝菌中砷元素含量测定及食用安全评价

通过ICP-AES法测定了26个云南野生牛肝菌居群中As元素含量,分析不同地区、种类牛肝菌对As的富集特征;采用单项污染指数法评价云南野生牛肝菌的As污染水平;根据FAO/WHO规定的每周As允许摄入量评估野生牛肝菌的As暴露风险。结果显示:(1)不同产地、种类牛肝菌中As含量差异明显,其中菌盖的As平均含量在(0.18±0.31)~(13.33±2.21)mg·kg~(-1)dw之间,菌柄的As平均含量在(0.06±0.10)~(17.09±5.8)mg·kg~(-1)dw之间;表明牛肝菌对As元素的富集程度与牛肝菌种类、生长环境等因素有关;(2)不同种类牛肝菌菌盖、菌柄的As污染指数分别在0.35~26.66及0.12~34.20之间,且多数牛肝菌的As污染指数大于1,表明多数牛肝菌的As含量超过GB2762-2012规定的限量标准,处于重污染水平;(3)若成年人每周食用500 g新鲜牛肝菌,则通过牛肝菌摄入的As均低于FAO/WHO规定的PTWI标准(As≤0.9 mg),未达到As暴露水平;然而日常生活中人们除了通过野生牛肝菌摄入As元素外还会通过其他食物(大米、肉类等)、饮水、呼吸等途径摄入As元素,因此,为了防止As暴露危害人体健康,不宜大量或长期食用野生牛肝菌。     

太湖聚藻区水华易发季节沉积物磷的分布特征

为了探讨太湖聚藻区月亮湾在水华易发季节及前后沉积物磷的赋存及迁移特征,采用欧洲标准测试委员会框架下发展的SMT磷形态分级方法对月亮湾由冬季至夏季（1～7月）表层沉积物（5 cm）分层的磷形态分析发现,总磷和无机磷呈现逐渐下降的趋势,平均含量分别为53553和42590 mg/kg。但有机磷则在冬季至夏初降低,随后从夏初开始上升并于7月达最大值,平均含量为8772 mg/kg,是冬季的14～18倍,表明藻类聚集和沉降对表层沉积物有机磷含量产生显著影响。在监测的这几个月中,无机形态磷均于春季4月达到最大值,而且与1、6和7月表现出显著的差异性（P <005）。铁磷为无机磷主要形态,平均含量达到18686 mg/kg,占无机形态磷质量分数的4443%,且4月、5月和6月沉积物铁磷含量表现出显著的差异性（P <005）。其次是铝磷和钙磷,平均含量分别达到12949和9748 mg/kg,为无机形态磷质量分数的3118%和2318%,各月份沉积物铝磷含量表现出显著的差异性（P<005）,而钙磷却无显著性差异。沉积物中可交换态磷的含量虽然较少（平均444 mg/kg）,但其冬季至春季逐渐升高、春季至夏季逐渐降低的现象,表明在生长季节可交换态磷从沉积物向上覆水柱释放,为藻类复苏和生长提供物资基础。分析还发现,铁磷、铝磷和有机磷均与可交换态磷存在较好相关性,无机磷与总磷的相关性最为显著,表明研究区沉积物中总磷的含量与分布主要受控于无机磷