“非正常”凋落物对冰雪灾后南岭森林土壤有机碳的影响

2008年初,一场百年罕见的冰雪灾害袭击了我国南方地区,对南方19个省（区）的林区,相当中国森林面积的13%（1.86×107 hm2）的森林植被遭受整体性、毁灭性破坏,导致的大量“非正常”凋落物必将对森林土壤碳循环产生深远影响。本研究以广东乐昌杨东山十二度水省级自然保护区不同海拔梯度上受灾的常绿阔叶混交林3种森林群落为研究对象,采用去除冰雪灾害导致的“非正常”凋落物与受损林地进行对照试验,对冰雪灾害所导致“非正常”凋落物对土壤碳的影响进行了研究。研究结果表明：灾后3种森林群落中不同深度土壤的有机碳质量分数和储量持续增加,同一深度土壤有机碳质量分数和碳储量在不同年份之间差异显著。直至2011年“非正常”凋落物分解完毕时,10~50 cm的土壤有机碳质量分数与上一年相比有减少趋势;0~10 cm的土壤有机碳质量分数稍比2010年高,但变化差异不显著(p=0.36),说明在“非正常”凋落物分解结束后土壤有机碳质量分数有减小的趋势,致使土壤碳储量下降。去除“非正常”凋落物样地与对照样地相比,各土壤深度的土壤有机碳质量分数明显下降,年平均下降百分比例变化范围为12.14%~55.34%,0~10 cm和10~30 cm土壤的有机碳质量分数下降变化波动幅度要比30~50 cm大;不同深度土壤有机碳质量分数与凋落物有机碳失质量间具有显著的线性相关性。可见,冰雪灾害导致的“非正常”凋落物对土壤有机碳质量分数和储量都有十分显著的影响,“非正常”凋落物的分解输入能显著提高土壤有机碳质量分数和储量。     

继电保护省、地一体化整定计算关键技术研究

为了提高整定计算工作的效率和正确性,采用图形建模方式、分层加载模型技术和快速整定计算新方法,研究开发了一套继电保护省、地一体化整定计算系统。有效地保证了两级电网应用的安全。应用结果表明:该系统规范了宁夏区调继电保护信息管理工作,为实现多级电网联合整定计算提供了技术支持。     

水体Hg~(2+)对中华绒螯蟹肝胰腺和血淋巴酶活性的影响

以中华绒螯蟹(Eriocheir sinensis)作为暴露生物,检测了水体Hg2+对中华绒螯蟹肝胰腺、血淋巴谷丙转氨酶(GPT)、谷草转氨酶(GOT)、碱性磷酸酶(AKP)和酸性磷酸酶(ACP)活性的影响。结果表明,肝胰腺中GPT和GOT活性随水体中Hg2+浓度(0.01～0.30mg·L-1)升高而降低;中华绒螯蟹血淋巴中GPT和GOT活性变化趋于分化,0～0.05mg·L-1暴露组,随Hg2+浓度升高血淋巴GPT活性迅速上升,0.10～0.30mg·L-1暴露组,随Hg2+浓度升高血淋巴GPT活性迅速下降;GOT活性随着水体Hg2+暴露浓度的升高则持续上升,表现出"剂量-效应"正相关;两种组织中AKP和ACP活性随暴露浓度的升高都表现出"低-高-低"的变化趋势,并且最高值均出现在0.05mg·L-1的Hg2+处理组。4种酶活性对水环境中Hg2+反应灵敏,可作为中华绒螯蟹毒理学评价指标以及重金属监测指标。     

B类滤毒罐防护磷化氢性能评价探讨

磷化氢是粮食仓储企业使用效果最好的杀虫剂,是一种剧毒的气体熏蒸剂。所以对于从业人员来讲,安全防护就显得格外重要。长期以来粮食仓储企业一直使用自吸过滤式防毒面具(配套选用B类滤毒罐)为首选器材。近期业内对B类滤毒罐防护磷化氢的有效性提出质疑,为此,本文通过性能评价试验,说明B类滤毒罐防护磷化氢是有效的,并从理论上说明B类滤毒罐防护磷化氢是有科学依据的。     

风障联合压实防治煤堆自燃技术工艺参数优化

为提高煤堆自燃的防治效果,降低经济成本和提高施工的灵活性,基于煤堆自燃理论,使用COMSOLMultiphysics 5.0数值仿真软件,建立煤堆自燃模型,研究了煤堆最高温度和自然发火期变化及相关措施实施后最高温度降低规律,对比了单独压实、独立风障和风障联合压实的温度降低量,优化了联合措施的工艺。结果表明,煤堆孔隙率越小,自燃风速范围越宽,最小、最易、最大自燃风速越大;单独进行煤堆压实存在因孔隙率增加而降低的最低不宜风速;针对6 m高煤堆单独使用风障时,只有风障高12 m、距离煤堆25 m才能避免煤堆自燃;风障联合压实措施中,风障高7.5~9 m,设置距离煤堆10~30 m即能保证煤堆不自燃。说明联合的煤堆最高温度降低量更大,且能扩大压实的适用范围,降低风障高度,节约经济成本,增加风障现场施工的灵活性。     

铁矿石烧结行业二噁英类形成机制与排放水平

铁矿石烧结是我国重要的二噁英类(PCDD/Fs)排放源之一.本文总结了烧结过程PCDD/Fs的生成机制,以及典型烧结烟气的PCDD/Fs排放特征.针对影响PCDD/Fs生成的关键因素进行了分析,探讨了原料组成中关键元素的影响,以及温度、时间和氧气含量等条件的影响,进而对PCDD/Fs的减排技术等方面进行了讨论.最后本文还对部分发达国家和我国的铁矿石烧结行业PCDD/Fs排放现状进行了分析和展望.可为我国铁矿石烧结行业PCDD/Fs的管理和减排提供参考.     

钯/泡沫镍阴极对水中微量氯贝酸的电催化氢化还原脱氯研究

氯贝酸（Clofibric acid, CA）是一种常见药品和个人护理品（PPCPs）类物质,在环境中具有持久性和稳定性.常规的水处理技术难以去除微量的CA,采用电催化氢化脱氯的方法可有效实现脱氯.本研究考察了CA初始浓度、工作电位、阴极液初始pH、反应温度、钯载量和电解质Na₂SO₄的浓度等多种因素对氯贝酸降解的影响.结果表明,CA的脱氯降解符合一级动力学方程,在工作电位为-0.85 V vs Ag/AgCl,钯负载量为0.20 mg·cm^-2,Na₂SO₄浓度为10 mmol·L^-1,初始阴极液pH为4.6,反应温度控制在303 K时,经过120 min的反应后,初始浓度为5 mg·L^-1的CA降解率达98%.因此利用钯/泡沫镍电极电催化还原降解废水中的CA具有很大的应用潜力.     

关于加强我国企业环境保护审计工作的探讨

介绍了企业环境保护审计工作的现状，指出环保部门与审计部门联合是企业环境保护审计开展的关键，并提出开展企业环境保护审计工作的意义和相关建议。     

Characterization of mechanochemical treated fly ash from a medical waste incinerator

The mechanochemical treatment of fly ash generated from a medical waste incinerator was subjected to grinding for 2 hr at 400 r/min in a planetary ball mill. The treated fly ash was characterized by a suite of analytical methods including High Resolution Gas Chromatograph/High Resolution Mass Spectrometer, Mastersizer 2000 Particle Size Analyzer, QUADRASORBTM SI Surface Area Analyzer, Scanning Electron Microscopy and X-ray di raction. Results showed that abatement e ciency of polychlorinated dibenzop- dioxins and polychlorinated dibenzofurans (PCDDs/Fs) in terms of total concentration averagely amount to 76% which was relatively higher than that of I-TEQ concentration averagely amount to 56%; the most concentration of toxic congeners as well as isomers of PCDDs/Fs decreased after mechanochemical treatment. The treated fly ash was characterized by a more homogeneous distribution of concaves as well as the significant decreasing in overall particle size and great enlargement in surface area. The major crystallization phases or intensities were considerably changed by mechanochemical treatment, of which a new phase containing chlorine formed may be a possible factor suggesting chlorination reaction occurring on the crystalline surface.     

Interactive e ect of dissolved organic matter and phenanthrene on soil enzymatic activities

The investigation of dissolved organic matter (DOM) on urease, catalase and polyphenol oxidase activity in a phenanthrene (Phe)- contaminated soil was conducted under laboratory incubation conditions. Values of soil enzymatic activity depended mainly on incubation time. In the initial 16 days, urease activity increased, and was followed by a decrease. In the initial 8 days, catalase activity decreased and then increased. Variation of polyphenol oxidase activity was just the reverse of catalase activity. After 30 days of incubation, no pronounced di erence among treatments with Phe, Phe and DOM, and control were detected in urease, catalase and polyphenol oxidase activity. Phe might inhibit urease and catalase, and stimulate polyphenol oxidase. DOM could improve inhibition of Phe in soil urease and catalase activity during the initial period of applying DOM. Nevertheless, DOM had no significant e ect on polyphenol oxidase activity in the Phe contaminated soil. There was a negative correlation between catalase and polyphenol oxidase (r = –0.761***), and catalase and urease (r = –0.554**). Additionally, a positive correlation between polyphenol oxidase and urease was also detected (r = 0.701***). It is implied that the formed DOM after application of organic wastes into soils may counteract the inhibition of polycyclic aromatic hydrocarbons in soil enzyme activities.