美国校园安全管理探析与启示

美国是世界上最早探索如何有效保障校园安全的国家之一。本文以美国校园安全为研究对象,分别从校园安全治理组织框架、法律法规体系、安全管理模式、巩固提升与持续改进4个方面进行分析,较为系统、深入地对美国校园安全管理现状进行了剖析。依据美国校园安全管理经验,结合我国校园安全管理实际情况,提出对我国校园安全管理的一些启示。     

Preliminary investigation of phosphorus adsorption onto two types of iron oxide-organic matter complexes

Iron oxide(FeO)coated by natural organic matter(NOM)is ubiquitous.The associations of minerals with organic matter(OM)significantly changes their surface properties and reactivity,and thus affect the environmental fate of pollutants,including nutrients(e.g.,phosphorus(P)).In this study,ferrihydrite/goethite-humic acid(FH/GE–HA)complexes were prepared and their adsorption characteristics on P at various p H and ionic strength were investigated.The results indicated that the Fe O–OM complexes showed a decreased P adsorption capacity in comparison with bare Fe O.The maximum adsorption capacity(Q_(max))decreased in the order of FH(22.17 mg/g)FH-HA(5.43 mg/g)GE(4.67 mg/g)GE-HA(3.27 mg/g).After coating with HA,the amorphous FH–HA complex still showed higher P adsorption than the crystalline GE–HA complex.The decreased P adsorption observed might be attributed to changes of the Fe O surface charges caused by OM association.The dependence of P adsorption on the specific surface area of adsorbents suggests that the Fe O component in the complexes is still the main contributor for the adsorption surfaces.The P adsorptions on Fe O–HA complexes decreased with increasing initial p H or decreasing initial ionic strength.A strong dependence of P adsorption on ionic strength and p H may demonstrate that outer-sphere complexes between the OM component on the surface and P possibly coexist with inner-sphere surface complexes between the Fe O component and P.Therefore,previous over-emphasis on the contributions of original minerals to P immobilization possibly over-estimates the P loading capacity of soils,especially in humic-rich areas.     

Comparison of surface water chemistry and weathering effects of two lake basins in the Changtang Nature Reserve, China

The geochemistry of natural waters in the Changtang Nature Reserve,northern Tibet,can help us understand the geology of catchments,and provide additional insight in surface processes that influence water chemistry such as rock weathering on the Qinghai–Tibet Plateau.However,severe natural conditions are responsible for a lack of scientific data for this area.This study represents the first investigation of the chemical composition of surface waters and weathering effects in two lake basins in the reserve(Lake Dogaicoring Qiangco and Lake Longwei Co).The results indicate that total dissolved solids(TDS)in the two lakes are significantly higher than in other gauged lakes on the Qinghai–Tibet Plateau,reaching 20–40 g/L,and that TDS of the tectonic lake(Lake Dogaicoring Qiangco)is significantly higher than that of the barrier lake(Lake Longwei Co).Na+and Cl-are the dominant ions in the lake waters as well as in the glacier-fed lake inflows,with chemical compositions mainly affected by halite weathering.In contrast,ion contents of inflowing rivers fed by nearby runoff are lower and concentrations of dominant ions are not significant.Evaporite,silicate,and carbonate weathering has relatively equal effects on these rivers.Due to their limited scope,small streams near the lakes are less affected by carbonate than by silicate weathering.     

过渡金属元素掺杂改性SCR对零价汞的催化氧化性能

为提高商用SCR催化剂对Hg0(零价汞)的催化氧化活性,研究了过渡金属对其进行掺杂改性的方法,并利用固定床反应平台考察了不同试验条件下改性催化剂对Hg0的氧化效率. 结果表明:Y、Zn、Ni和Zr等过渡金属的掺杂可明显抑制SCR催化剂的催化活性,而Fe、Cu掺杂改性SCR催化剂对Hg0的催化氧化性能有显著提升. 在反应温度为350 ℃、空速比为370 000 h-1、φ(HCl)为1×10-5的条件下,Fe、Cu掺杂改性的SCR催化剂对Hg0的氧化效率均能达到90%以上,并且Fe掺杂改性后的SCR催化剂的脱硝性能也未受到明显影响. 借助XRD和XPS等表征手段,对反应前后Fe掺杂改性SCR催化剂进行了研究,表明Fe改性SCR催化剂遵循Mars-Maessen和Langmuir-Hinshelwood机制,可明显提高对Hg0的催化氧化效率,因此,应用前景较好.      

天津市挥发性有机物排放控制标准与污染源在线监控技术研究

大气中的VOCs和NOx在发生光化学反应后不易沉降,易造成大气能见度差等现象.“十二五”期间中国重点区域和重点行业开展了挥发性有机物(VOCs)污染防治工作,依据环境管理的需求,天津市开展了挥发性有机物排放控制标准制定与污染源在线监控技术研发,建立VOCs综合控制指标和苯系物单项控制指标,覆盖全部工业VOCs排放行业,推行VOCs在线监测与无组织泄漏检测,研发监测数据具有代表性和可比性、低成本、安全性高且易推广的VOCs污染源在线监测系统.     

Preparation of various thiol-functionalized carbon-based materials for enhanced removal of mercury from aqueous solution

In this work, biochar (BC), activated carbon (AC), and graphene oxide (GO) were thiol-functionalized using 3-mercaptopropyltrimethoxysilane (3-MPTS) (named as BCS, ACS, and GOS, respectively). BCS, ACS, and GOS were synthesized mainly via the interaction between hydrolyzed 3-MPTS and surface oxygen-containing functional groups (e.g., –OH, O–C=O, and C=O) and π-π interaction. The materials before and after modification were characterized and tested for mercury removal, including sorption kinetics and isotherms, the effects of adsorbent dosage, initial pH, and ionic strength. Pseudo-second-order sorption kinetic model (R² = 0.992~1.000) and Langmuir sorption isotherm model (R² = 0.964~0.998) fitted well with the sorption data of mercury. GOS had the most –SH groups with the largest adsorption capacity for Hg²⁺ and CH₃Hg⁺ (449.6 and 127.5 mg/g), followed by ACS (235.7 and 86.7 mg/g) and BCS (175.6 and 30.3 mg/g), which were much larger than GO (96.7 and 4.9 mg/g), AC (81.1 and 24.6 mg/g), and BC (95.6 and 9.4 mg/g). GOS and ACS showed stable mercury adsorption properties at a wide pH range (2~9) and ionic strength (0.01~0.1 mol/L). Mercury maybe removed by ligand exchange, surface complexation, and electrostatic attraction.

     

大气环境质量模糊积分评价新方法

本文提出了应用模糊积分进行大气环境质量综合评价的具体方法和步骤,并用这一方法进行大气环境质量评价,取得了令人满意的结果。该方法的优点是简便实用,评价结果可靠。     

Crystalline phase evolution behavior and physicochemical properties of glass–ceramics from municipal solid waste incineration fly ash

Journal of Material Cycles and Waste Management - Appropriate management and treatment of fly ash from municipal solid waste (MSW) incineration plant have become an urgent environmental protection...     

高温碟型双金属片动作响应特性技术研究

高温碟形双金属片是火警温度继电器的核心元件，结构复杂，为了研究其受热动作响应特性，采用有限元分析方法，通过Solidworks结合ANSYS对双金属片进行热-结构耦合场分析，获得了碟形双金属片的受热动作响应特性，并且通过不断改变高温碟形双金属片的外形结构进行求解分析，根据分析结果总结高温碟形双金属片的结构与其受热动作响应特性之间的关系，为高温碟形双金属片的结构参数设计和数据调节提供理论依据。