The impact of traditional coffee processing on river water quality in Ethiopia and the urgency of adopting sound environmental practices

Although waste from coffee processing is a valuable resource to make biogas, compost, and nutrient-rich animal food, it is usually dumped into nearby water courses. We carried out water quality assessment at 44 sampling sites along 18 rivers that receive untreated waste from 23 coffee pulping and processing plants in Jimma Zone, Ethiopia. Twenty upstream sampling sites free from coffee waste impact served as control, and 24 downstream sampling sites affected by coffee waste were selected for comparison. Physicochemical and biological results revealed a significant river water quality deterioration as a result of disposing untreated coffee waste into running water courses. During coffee-processing (wet) season, the highest organic load (1,900?mg/l), measured as biochemical oxygen demand, depleted dissolved oxygen (DO) to a level less than 0.01?mg/l, and thus curtailed nitrification. During off season, oxygen started to recuperate and augmented nitrification. The shift from significantly elevated organic load and reduced DO in the wet season to increased nitrate in the off season was found to be the determining factor for the difference in macroinvertebrate community structure as verified by ordination analysis. Macroinvertebrate diversity was significantly reduced in impacted sites during the wet season contrary to the off season. However, there was a significant difference in the ratio of sensitive to pollution-tolerant taxa in the off season, which remained depreciated in the longer term. This study highlights the urgency of research exploring on the feasibility of adopting appropriate pollution abatement technologies to implement ecologically sound coffee-processing systems in coffee-growing regions of Ethiopia.     

Development and preparation of lead-containing paint films and diagnostic test materials

Lead in paint continues to be a threat to children's health in cities across the United States, which means there is an ongoing need for testing and analysis of paint. This ongoing analytical effort and especially development of new methods continue to drive the need for diagnostic testing materials that provide the analytical challenges of real-world paints. To this end, 31 different types of paint test materials were developed and prepared. Preparation of the materials included development of lead-containing paint films yielding an overall relative standard error for one individual test sample being less than 10%. The 31 diagnostic test materials prepared with these paint films included two lead pigments; lead concentrations from nominally 0 to 2.0 mg lead/cm(2) (0 to 5% lead by weight); overlayers of both "lead-free," oil-based and water-based paints; Al, Ba, and Mg as potential chemical interferents; red and black potential color interferents; and substrates of wood, metal, masonry, and plaster. These materials challenge each step in method development and evaluation, including paint sample collection and preparation, lead extraction, and measurement of solubilized lead. When the materials were used to test performance of a new lead-in-paint testing method based on extraction using a rotor/stator method and measurement using turbidimetry, the results agreed to within ±20% of the expected lead values for 30 out of 31 of the diagnostic test materials, thereby demonstrating their levels of quality and utility.     

An air quality balance index estimating the total amount of air pollutants at ground level

A new index named Air Quality Balance Index (AQBI), which is able to characterise the amount of pollution level in a selected area, is proposed. This index is a function of the ratios between pollutant concentration values and their standards; it aims at identifying all situations in which there is a possible environmental risk even when several pollutants are below their limit values but air quality is reduced. AQBI is evaluated by using a high-resolution three-dimensional dispersion model: the air concentration for each substance is computed starting from detailed emissions sources: point, line and area emissions hourly modulated. This model is driven with accurate meteorological data from ground stations and remote sensing systems providing vertical profiles of temperature and wind; these data are integrated with wind and temperature profiles at higher altitudes obtained by a Local Area Model. The outputs of the dispersion model are compared with pollutant concentrations provided by measuring stations, in order to recalibrate emission data. A three-dimensional high resolution grid of AQBI data is evaluated for an industrial area close to Alessandria (Northern Italy), assessing air quality and environmental conditions. Performance of AQBI is compared with the Air Quality Index (AQI) developed by the U.S. Environmental Protection Agency. AQBI, computed taking into account all pollutants, is able to point out situations not evidenced by AQI, based on a preset limited number of substances; therefore, AQBI is a good tool for evaluating the air quality either in urban and in industrial areas. The AQBI values at ground level, in selected points, are in agreement with in situ observations.     

乌鲁木齐采暖期TSP、PM10、PM5、PM2.5中重金属污染水平评价

采用石墨炉原子吸收分光光度法、双道原子荧光光谱法研究乌鲁木齐市采暖期前期与后期不同粒径大气颗粒物(TSP、PM_(10)、PM_5、PM_(2.5))中Hg、As、Zn、Pb、Ni等5种重金属元素的质量浓度,并对重金属污染水平进行评价。Hg质量浓度为0.3~5.7 ng/m3;As质量浓度为15.3~122.5 ng/m~3;Zn质量浓度为298.0~1 686.5 ng/m~3;Pb质量浓度为0.5~88.8 ng/m~3;Ni质量浓度为10.4~25.5 ng/m~3。Igeo计算得出采暖期后期的TSP、PM_(10)、PM_5、PM_(2.5)中各重金属Igeo值均高于采暖期前期,其中Hg元素为严重污染;富集因子分析得出Hg、Zn元素的EFi值大于10,说明这些元素是人为源贡献。通过研究乌鲁木齐市不同时期、不同粒径大气颗粒物中各种重金属污染状况,为乌鲁木齐大气污染治理提供科学支持。     

Characterisation of particulate matter on the receptor level in a city environment

Airborne particulate matter (PM) has become one of the dominant pollutants with the increasing material and energy demand due to global economic growth. The main objective of this research is to provide a comprehensive receptor level characterisation of the particulate matter collected in a city environment. Particulate matter samples were collected on Tapered Element Oscillating Microbalance (TEOM) filters from five monitoring sites over a period of 1 year. An Andersen eight-stage cascade impactor was also used to collect airborne PM samples from three other locations to compare with the samples collected by TEOM. All the samples were then subjected to individual particle morphology and chemical composition analysis by SEM/EDS. Bulk chemical composition of the samples were also analysed through ICP–OES. Based on these analyses, possible sources of the PM samples were identified. The results showed that the monitoring sites in residential environments were dominated by transportation-derived particles and other migratory particulates. Monitoring sites near the city centre were dominant by particles from transportation, with biological particles abundant for the site closer to a river. The monitoring station located close to the industrial area, despite only 200 m away from a motorway, has low contribution of non-exhaust particulates from vehicles. Instead, the particulates collected from this site were dominated by industrial sources. An air dispersion modelling package was also used to model the particulate matter dispersion in the city area for the period of sampling. The results from the model showed that the points of high emissions were around industrial areas.     

The decline and residues of hexaconazole in tomato and soil

The decline and terminal residues of hexaconazole in tomato and soil in open field were studied. Hexaconazole residues were determined by gas chromatography coupled with an electron capture detector. Recoveries were between 89% and 110% with RSD of 2.99–5.88% in tomato and 90–119% with RSD of 1.15–5.76% in soil at spiked levels of 0.01, 0.1, and 1 mg/kg, respectively. The limit of detection of hexaconazole was 6.3 × 10⁻¹² g. The decline rates of hexaconazole were described using first-order kinetics and the mean half-lives of hexaconazole in tomato and soil were 4.3 and 18.1 days, respectively. The terminal residues in tomato at interval of 7 days at the dosage of 150 g.a.i./hm² for three or four times were all below 0.1 mg/kg. This work would be the guidance of establishing the maximum residue limit of hexaconazole in tomato in China.     

澳大利亚金刚石的勘探和开发

1851年首次报道了澳大利亚发现金刚石。但是,直到1960年才用现代勘探理论和勘探技术初步证明该大陆存在着可能含金刚石的金伯利岩;高潮出现在1970—1980年期间,当时在西澳大利亚州金伯利地区的阿盖尔发现了具有经济价值的金刚石砂矿和钾镁煌斑岩岩管型原生金刚石矿床。本文重点阐述了阿盖尔金刚石矿床的发现史、金伯利地区的区域地质、勘探技术,以及阿盖尔金刚石选矿厂和预料1986年金刚石产量可达2800万克拉的矿山的发展。     

新西兰怀特岛火山─热液系统代表强硫化Cu-Au矿床地球化学环境

新西兰怀特岛火山-热液系统被认为充分地代表了导致强硫化Cu－Au矿床形成的化学条件。计算出了主要由脱气岩浆在1万年时期内活动所产生的Cu和Au量分别为106t和45t。现代火山口喷发的蚀变安山岩岩块含有明矾石、硬石膏和黄铁矿。它们的S同位素组成表明是在～380℃温度下进行脉体充填的。在此温度下，Cu和Au可高度溶解于酸性溶液中，这可解释喷出物中贫Cu和缺Au的现象。但是质量平衡计算表明，Cu和Au都是在酸性溶液排出到地表之前沉淀于冷却带中的。     

Beetle adhesive hairs differ in stiffness and stickiness: in vivo adhesion measurements on individual setae

Leaf beetles are able to climb on smooth and rough surfaces using arrays of micron-sized adhesive hairs (setae) of varying morphology. We report the first in vivo adhesive force measurements of individual setae in the beetle Gastrophysa viridula, using a smooth polystyrene substrate attached to a glass capillary micro-cantilever. The beetles possess three distinct adhesive pads on each leg which differ in function and setal morphology. Visualisation of pull-offs allowed forces to be measured for each tarsal hair type. Male discoidal hairs adhered with the highest forces (919?±?104?nN, mean?±?SE), followed by spatulate (582?±?59?nN) and pointed (127?±?19?nN) hairs. Discoidal hairs were stiffer in the normal direction (0.693?±?0.111?N?m^?1) than spatulate (0.364?±?0.039?N?m^?1) or pointed (0.192?±?0.044?N?m^?1) hairs. The greater adhesion on smooth surfaces and the higher stability of discoidal hairs help male beetles to achieve strong adhesion on the elytra of females during copulation. A comparison of pull-off forces measured for single setae and whole pads (arrays) revealed comparable levels of adhesive stress. This suggests that beetles are able to achieve equal load sharing across their adhesive pads so that detachment through peeling is prevented.