Strategies to save energy in the context of the energy crisis: a review

Environmental Chemistry Letters - New technologies, systems, societal organization and policies for energy saving are urgently needed in the context of accelerated climate change, the Ukraine...     

Optimizing hydrogen production by alkaline water decomposition with transition metal-based electrocatalysts

Burning fossil fuels account for over 75% of global greenhouse gas emissions and over 90% of carbon dioxide emissions, calling for alternative fuels such as hydrogen. Since the hydrogen demand could reach 120 million tons in 2024, efficient and large-scale production methods are required. Here we review electrocatalytic water splitting with a focus on reaction mechanisms, transition metal catalysts, and optimization strategies. We discuss mechanisms of water decomposition and hydrogen evolution. Transition metal catalysts include alloys, sulfides, carbides, nitrides, phosphides, selenides, oxides, hydroxides, and metal-organic frameworks. The reaction can be optimized by modifying the nanostructure or the electronic structure. We observe that transition metal-based electrocatalysts are excellent catalysts due to their abundant sources, low cost, and controllable electronic structures. Concerning optimization, fluorine anion doping at 1 mol/L potassium hydroxide yields an overpotential of 38 mV at a current density of 10 mA/cm². The electrocatalytic efficiency can also be enhanced by adding metal atoms to the nickel sulfide framework.

     

国家清洁生产中心的金融可持续性:洪都拉斯国家清洁生产中心的经验

洪都拉斯国家清洁生产中心于2000年成立,加拿大国际开发署(CIDA)为中心前五年的运行提供资助.CIDA还在1998年资助了中心的可行性研究和项目设计.顾问们制定的实施战略把金融可持续性定为一个主要目标.推荐了用于成本回收的详细机制,以及一些中心服务费用分担办法.剩余资金将被加入可持续性基金.在这一方面已经取得了重大进展.到2003年这一基金的数目之大导致CIDA的捐款仅占中心业务预算的50%;剩余部分来自参与企业.本文介绍了中心所执行战略的基本内容、挑战、进展和在努力实现金融可持续性的过程中获得的经验.     

Concentrations of Cu and Pb in the offshore and intertidal sediments of the west coast of Peninsular Malaysia

Malaysia is now a developing country and on her way towards being an industrialised one by the year 2020. Most of her industries and urban areas are located on the west coast of Peninsular Malaysia. In addition, the offshore area of the west coast is now one of the busiest shipping lanes in the world. These two phenomena make the intertidal and offshore areas of the west coast of Peninsular Malaysia interesting for scientific studies. Therefore, this study focused on both the offshore and intertidal sediments of the west coast of Peninsular Malaysia. Sampling for sediment samples were done from the northern to the southern ends of the peninsula and these sediment samples were analysed for Cu and Pb. It was found that total Cu concentrations ranged from 0.25 to 13.8 and 0.40 to 315 microg/g dry weight (dw) for offshore and intertidal sediments, respectively. For Pb, it ranged from 3.59 to 25.4 and 0.96 to 69.8 microg/g dw for the offshore and intertidal sediments, respectively. The ranges of Cu and Pb found from the west coast of Peninsular Malaysia were low in comparison to regional data. However, some intertidal areas were identified as receiving anthropogenic Cu and Pb. Geochemical studies revealed that the 'nonresistant' fraction for Pb contributed about 70.0% to 75.0% and 54.0% of the total Pb concentration in the offshore and intertidal sediments, respectively. As for Cu, the 'nonresistant' fraction contributed about 46.2% to 60.4% and 46.3% of the total Cu concentration in the offshore and intertidal sediments, respectively. The 'nonresistant' fraction contained mostly of anthropogenic metals besides natural origins. These 'nonresistant' percentages indicated that both the offshore and intertidal areas could have received anthropogenic-derived metals, which could be influenced by physico-chemical properties of the sediments. Although the present data indicated that contamination due to Cu and Pb in the west coast of Peninsular Malaysia especially in the offshore areas were not serious, regular biomonitoring studies along the west coast of Peninsular Malaysia are recommended.     

Classification of a Malaysian river using biological indices: a preliminary attempt

Local biota and their ecological attributes as indicators of changing conditions in aquatic ecosystems were used to classify the Bernam River, Malaysia. A biological diversity index and a pollution index were adopted for comparison purposes, namely the Shannon–Weaver diversity index and the saprobic system concept of Kolkwitz and Marsson. The collected data on phytoplankton communities and the dissolved oxygen and nitrate concentrations permitted a comparative evaluation of the two indices in assessing the ecosystem health of the river. The Shannon–Weaver diversity index approach appeared to give interesting and interpretable classification results, as compared with the saprobic condition index. The study illustrates how ecological knowledge may be used in the integrated management of natural river environments. However, the identifed areas of uncertainty and practicability of the developed biological scheme need to be considered critically.     

Risk assessment for the daily intake of polycyclic aromatic hydrocarbons from the ingestion of cockle （Anadara granosa） and exposure to contaminated water and sediments along the west coast of Peninsular Malaysia

The concentration of carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) present in the sediment and water of Peninsular Malaysia as well as in the cockle Anadara granosa was investigated. Samples were extracted and analysed with gas chromatographymass spectrometry. The concentrations of total carcinogenic polycyclic aromatic hydrocarbons (t-PAHs) were measured between 0.80 0.04 to 162.96 14.74 ng/g wet weight (ww) in sediment, between 21.85 2.18 to 76.2 10.82 ng/L in water samples and between 3.34 0.77 to 46.85 5.50 ng/g ww in the cockle tissue. The risk assessment of probable human carcinogens in the Group B2 PAHs was calculated and assessed in accordance with the standards of the United States Environmental Protection Agency (US EPA). Case I in the toxicity assessment analysed the cancer risk to consumers of Malaysian blood cockle. Case II assessed the risk of cancer from exposure to PAHs from multiple pathways. The average cancer risk of case I and case II were found to be classifiable as unsafe according to the US EPA standard. The cancer risk due to c-PAHs acquired by the ingestion of blood cockle was (8.82 0.54) 10??6 to (2.67 0.06) 10??2, higher than the US EPA risk management criterion. The non-cancer risks associated with multiple pathways in Kuala Gula, Kuala Juru and Kuala Perlis were higher than the US EPA safe level, but the non-cancer risk for eating blood cockle was below the level of US EPA concern.     

Floating particles with high copper concentration in the sea-surface microlayer

This study sought to clarify whether suspended particles containing high Cu concentrations are present in the sea-surface microlayer (S-SML). For this reason, suspended particles (10–2000 μm) in the S-SML were collected periodically from a ship mooring pond during 2018–2020, and the acid-soluble Cu concentration in the suspended particles was measured as particulate Cu (P-Cu). The highest concentration of P-Cu in the S-SML of the pond was 75 μg L^?1 with a 90th percentile value of 2.5 μg L^?1. This is below P-Cu values reported for the S-SML in North American ports, but 140 times higher than this found in bulk seawater in the Atlantic Ocean. The highest P-Cu concentration in the S-SML of non-organism (abiotic) origin was 17 μg L^?1, and the abiotic P-Cu to P-Cu ratio varied from 0.2 to 100%, likely depending on the quality and quantity of biogenic material in the S-SML samples. It is assumed that the S-SML particles examined here contain high Cu concentrations originating from ship antifouling paints.

     

Correction to: Floating particles with high copper concentration in the sea-surface microlayer

Environmental Science and Pollution Research - A Correction to this paper has been published: https://doi.org/10.1007/s11356-021-14518-w     

Strategies to achieve a carbon neutral society: a review

Environmental Chemistry Letters - The increasing global industrialization and over-exploitation of fossil fuels has induced the release of greenhouse gases, leading to an increase in global...