从委托代理理论谈中国的环境影响评价制度

根据委托代理理论,分析了中国环境影响评价制度中存在的问题,立足于绿色招商的理念,理顺建设项目环评委托代理关系,明确了建设单位、环评单位、招商部门、环保部门等相互之间的关系和职责,以使中国的环境影响评价制度更适应新型工业化道路发展的要求。     

城市规划的环境影响评价研究初探

环境影响评价法的颁布是中国环境影响评价的一个新阶段。中国至今尚无明确的、系统的规划环境影响评价的技术导则和规范,其评价理论仍在探索之中。分析了国内外规划环境影响评价的历史和现状。从区域环境影响评价的实践经验总结出了城市规划环境影响评价应强调城市发展的可持续性。探讨了该层次评价的介入时间、评价原则、环境影响因素识别及评价内容,提出从生态合理性、绿色化程度等方面考虑城市规划的生态环境影响。     

高锰酸钾净水的氧化副产物研究

在高锰酸钾预氧化条件下 ,对北京京密引水渠水和松花江水进行混凝处理 ,并将原水与出水水样经色谱 质谱联用仪分析 ,以 1997年美国国家环保局 (USEPA)提出的饮用水规程和健康建议为标准 ,初步探讨了高锰酸钾净水过程中产生的副产物是否对人体有毒害作用 .试验结果表明 :在试验条件下 ,尚未发现高锰酸钾氧化生成USEPA规定的有毒有害副产物 ,并认为其原因可能与高锰酸钾氧化作用方式以及氧化过程中生成的新生态水合二氧化锰的吸附作用有关 .     

褐煤地下气化过程汞析出规律的研究

在褐煤地下气化模型试验的基础上 ,研究了褐煤中汞的赋存形态 ,褐煤地下气化煤气中汞含量的变化及存在形态 ,以及气化工艺的影响 ;分析了地下气化过程中汞的析出及反应机理 .实验结果表明 ,汞在试验褐煤中主要以硫化物结合态和残渣态形式存在 ;褐煤地下气化煤气中汞含量随气化时间的变化而变化 ,且主要以Hg0 (g)的形态存在 ;水蒸汽的存在会降低Hg0 (g)被其它气体氧化为Hg2 (g)的趋势 ;与地面气化及燃煤过程不同 ,煤地下气化产物中 ,气态汞占总汞比例低于 2 0 % ,明显低于地面气化及燃煤     

滇池水体和沉积物中营养盐的分布特征

在滇池外海不同方位选取6个采样点,研究了水质现状,沉积物Eh,pH,总氮,总磷以及间隙水重金属的剖面分布特征。结果表明,滇池水体仍属富营养化状态。在氧化表层下,Eh随沉积深度的增加迅速降低,沉积物深层为还原状态。pH在沉积物剖面变化不大,为7 0～8 5。滇池沉积物含有丰富的营养物质,总氮和总磷最高质量分数分别为8 67和3 46g kg。剖面分布表明,沉积物表层总氮和总磷含量远高于底层,在表层0～10cm含量随深度增加而迅速降低。重金属元素在水-土界面的浓度梯度为沉积物向水体的扩散提供了条件。不同采样点相比,位于昆明市附近的S6点沉积物内负荷较大。在外源减少的情况下,沉积物内负荷可能在一定时间内成为控制滇池水质的主导因子。      

基于位置误差概率模型的物流无人机安全间隔评估方法研究

针对未来多架物流无人机飞行在同一航线可能引起的安全冲突问题,提出规划无人机之间的安全间隔以规避运行风险.根据无人机在地面控制系统监控下的飞行特点,结合位置误差概率模型,综合考虑无人机定位误差、速度误差以及侧风的影响,依次建立无人机之间纵向、侧向和垂直方向的碰撞风险评估模型,并得出ICAO安全目标水平下的最小安全间隔.选...     

Improved product selectivity of electrochemical reduction of carbon dioxide by tuning local carbon dioxide concentration with multiphysics models

Environmental Chemistry Letters - Electrochemical reduction of carbon dioxide (CO2) is promising to alleviate carbon emissions and produce fuels and materials in a circular way, yet effective...     

Coupled electrochemical methods for nitrogen and phosphorus recovery from wastewater: a review

Environmental Chemistry Letters - Declining mineral resources, high fertilizer production cost and widespread eutrophication are calling for the recovery of nitrogen and phosphorus from wastewaters...     

China’s sponge cities alleviate urban flooding and water shortage: a review

Environmental Chemistry Letters - About one tenth of humans are impacted by water shortages around the globe. Water resilience is worsening under climate change because intensifying weather...     

Low-temperature caproate production,microbial diversity,and metabolic pathway in xylose anaerobic fermentation

● Converting xylose to caproate under a low temperature of 20 °C by MCF was verified. ● Final concentration of caproate from xylose in a batch reactor reached 1.6 g/L. ● Changing the substrate to ethanol did not notably increase the caproate production. ● Four genera, including Bifidobacterium , were revealed as caproate producers. ● The FAB pathway and incomplete RBO pathway were revealed via metagenomic analysis. Mixed culture fermentation (MCF) is challenged by the unqualified activity of enriched bacteria and unwanted methane dissolution under low temperatures. In this work, caproate production from xylose was investigated by MCF at a low temperature (20 °C). The results showed that a 9 d long hydraulic retention time (HRT) in a continuously stirred tank reactor was necessary for caproate production (~0.3 g/L, equal to 0.6 g COD/L) from xylose (10 g/L). The caproate concentration in the batch mode was further increased to 1.6 g/L. However, changing the substrate to ethanol did not promote caproate production, resulting in ~1.0 g/L after 45 d of operation. Four genera, Bifidobacterium, Caproiciproducens, Actinomyces, and Clostridium_sensu_stricto_12, were identified as the enriched caproate-producing bacteria. The enzymes in the fatty acid biosynthesis (FAB) pathway for caproate production were identified via metagenomic analysis. The enzymes for the conversion of (C_n+2)-2,3-Dehydroxyacyl-CoA to (C_n+2)-Acyl-CoA (i.e., EC 1.3.1.8 and EC 1.3.1.38) in the reverse β-oxidation (RBO) pathway were not identified. These results could extend the understanding of low-temperature caproate production.