Renewable hydrogen production: a technical evaluation based on process simulation

An evaluation of different hydrogen production technologies based on renewable raw materials and/or renewable energy is presented. The evaluation comprises alkaline electrolysis, steam reforming of both biogas and gasification gas, the coupled dark and photo fermentation as well as the coupled dark and biogas fermentation. Each technology is investigated with different plant layouts and/or different raw materials. All examined technologies are designed to produce hydrogen in a quality suitable for the use in mobile fuel cells. The presented evaluation is based on the hydrogen production efficiency and the energy efficiency of the processes.     

镇江市古运河和金山湖河湖上覆水体和沉积物氮及有机质分布特征及污染评价

镇江市位于长江和京杭大运河"十字黄金水道"的交汇处,是我国历史上最为重要的水上交通枢纽之一,区域内水量充沛、河网密布.近年来,该区域水环境存在不同程度的退化,故调查镇江市主要河湖水体及沉积物污染现状,将为当地水环境质量的改善提供重要的基础数据.基于此,本研究选择镇江市典型河湖水体共21个点位（金山湖10个点位,古运河及其支流共11个点位）,在冬夏两季采集上覆水及沉积物样品测定其理化指标和氮素含量,并通过有机指数及有机氮对沉积物污染程度进行评价.结果表明：①上覆水总氮（TN）浓度在冬夏季节分别介于1.95~15.71 mg·L^-1和0.64~12.09 mg·L^-1之间,平均值为4.01 mg·L^-1和4.07 mg·L^-1,平均值浓度高于地表水Ⅴ类标准.上覆水氨氮（NH₄⁺-N）浓度在季节上均表现为冬季<夏季,空间上则表现为河流>湖泊;②沉积物TN含量在冬夏两季分别介于394.61~3288.09 mg·kg^-1和869.21~3598.04 mg·kg^-1之间,平均值为1928.58 mg·kg^-1和2068.40 mg·kg^-1.湖泊沉积物TN、NH₄⁺-N、硝态氮（NO₃^--N）和有机氮（Org-N）含量均表现为冬季>夏季,而河流沉积物TN平均含量为冬季<夏季,NH₄⁺-N和NO₃^--N则表现为冬季>夏季,表明河流沉积物在季节上的分布规律更为复杂;空间上,冬夏两季沉积物NO₃^--N表现为湖泊>河流,NH₄⁺-N含量则表现为湖泊<河流.C/N结果表明研究区域沉积物有机质主要来源于内源污染;③湖泊和河流沉积物超过60%点位属于有机氮污染Ⅳ水平,即存在有机氮污染,而超过70%和54.55%的湖泊和河流沉积物处于有机指数Ⅱ类水平,即较清洁水平,表明镇江市河湖沉积物主要为氮素污染.以上研究结果将为镇江市河流水体及沉积物氮素控制提供重要的基础数据.     

Quantitative modelling of Ostracod bioassay: assigning toxicity index to potentially chemical contaminated swimming pools

Environmental Science and Pollution Research - One of the primary objectives of any public health programme is to design a protocol that will curtail a population from being predisposed to toxic...