Geochemistry of high arsenic groundwater in Chia-Nan plain, Southwestern Taiwan: possible sources and reactive transport of arsenic

Major ion, trace element, and stable isotope analyses were performed on groundwater samples collected during November 2005 and 2006 in Chia-Nan plain of southwestern Taiwan to examine As mobilization in aquifers. The high concentrations of As, Fe and Mn in the groundwater is consistent with low Eh values (under moderately reduced state). Moreover, the observed Na/Cl and SO(4)/Cl molar ratios in groundwater demonstrate the influence of seawater intrusion. Seawater intrusion could provide required electron acceptors (i.e., SO(4)) for bacterial sulfate reduction and promote reducing conditions that are favorable for As mobilization. The concurrent increases in the concentrations of Fe and Mn from 2005 to 2006 may be caused by bacterial Fe(III) and Mn(IV) reduction. Geochemical modeling demonstrate that As(III) is the dominant As species and the presence of Fe-bearing carbonates, sulfides, and oxide phases may locally act as potential sinks for As. Mud volcano fluids were also collected and analyzed to assess the possible source of As in the Chia-Nan plain groundwater. The oxygen and hydrogen isotopic signatures indicate that the As-rich mud volcano fluids may have been modified by chemical exchange with (18)O-rich crustal rocks and possibly originated from mixing of deep brines with circulating meteoric water. Thus As in the Chia-Nan plain groundwater may have been evolved from deep crustal fluids or rock sources. The hydrogeochemistry and widespread As enrichment in groundwater of Chia-Nan plain result from multiple processes, e.g., de-watering of deep crustal fluids, seawater intrusion, and biogeochemical cycling of Fe, As, and S in alluvial sediments.     

Commodity booms and their impacts on the Western Australian economy: The iron ore case

Western Australia is a resource-rich province. Since the 1890s, resources booms have played a key role in the development of the state's economy. In the last few years, Western Australia's resources industry has continued to enjoy exceptional conditions created by strong international demand for commodities. This paper aims to examine the likely impact of this commodity boom in the iron ore sector on the Western Australian economy, using a general equilibrium approach. The modeling results indicate that the Western Australian economy will benefit from the expansion in iron ore exports and investment in terms of rising consumption and employment, although at the industry level there will be losers as well as winners.     

Monitoring of pathogenic microorganisms contamination during heat drying process of sewage sludge

The sewage sludge from wastewater treatment plant is a potential source of infectious organism. The number and type of pathogens in sludge depends on various factors namely, the wastewater source, the type of treatment plant, and other environmental factors such as the biological medium offered by the sewage sludge. The principal sludge-borne diseases are presented followed by discussion on biological aspect of growth and occurrence. The overall objective of this work is to estimate kinetic reduction of pathogen population in sludge during different thermal-drying process including: the agitated conductive drying, drum drying, solar drying, and fry-drying. The temperature curves were reported from literature except frying data which were determined in experiment. In order to apply the temperature influence on pathogens population, kinetic parameters for the thermal inactivation (D, z-values) were chosen from literature. Values of concentrations of each pathogen were also extracted from scientific review of pathogens in bio-solids. This study conducted to resolve the survival kinetic of Hepatitis A viruses. The result showed that a concentration of 7 × 10⁴ cfu/100 ml initially present in the sewage sludge is significantly reduced during the heat drying processes except the solar plant. The sewage sludge is completely disinfected when heated for 20 min, 10 min, and 10 s, respectively, during the agitated conductive process, vacuum fry-drying, and drum drying process.     

学龄儿童呼吸系统疾病、症状影响因素研究

用非条件 Logistic回归分析方法研究空气污染对学龄儿童呼吸系统疾病、症状的影响。结果表明 ,控制年龄、性别、父亲和母亲受教育水平、住房结构、家庭烹饪燃料、厨房抽风设备、被动吸烟等因素 ,污染区儿童因呼吸系统疾病住院、患支气管炎和出现喘息症状的危险性分别是相对清洁区的 1 .6、1 .5和 1 .2倍 ;不感冒咳嗽或不感冒咳痰的发生与室外空气污染水平的关系均不明显 ;家庭烹饪使用不洁燃料、厨房通风不良、被动吸烟使喘息症状的发生机会增加 (尤其是厨房的通风状况不良 )     

Cooling of bat hibernacula to mitigate white-nose syndrome

White-nose syndrome (WNS) is a fungal disease that has caused precipitous declines in several North American bat species, creating an urgent need for conservation. We examined how microclimates and other characteristics of hibernacula have affected bat populations following WNS-associated declines and evaluated whether cooling of warm, little-used hibernacula could benefit bats. During the period following mass mortality (2013–2020), we conducted 191 winter surveys of 25 unmanipulated hibernacula and 6 manipulated hibernacula across Pennsylvania (USA). We joined these data with additional datasets on historical (pre-WNS) bat counts and on the spatial distribution of underground sites. We used generalized linear mixed models and model selection to identify factors affecting bat populations. Winter counts of Myotis lucifugus were higher and increased over time in colder hibernacula (those with midwinter temperatures of 3–6 °C) compared with warmer (7–11 °C) hibernacula. Counts of Eptesicus fuscus, Myotis leibii, and Myotis septentrionalis were likewise higher in colder hibernacula (temperature effects = –0.73 [SE 0.15], –0.51 [0.18], and –0.97 [0.28], respectively). Populations of M. lucifugus and M. septentrionalis increased most over time in hibernacula surrounded by more nearby sites, whereas Eptesicus fuscus counts remained high where they had been high before WNS onset (pre-WNS high count effect = 0.59 [0.22]). Winter counts of M. leibii were higher in hibernacula with high vapor pressure deficits (VPDs) (particularly over 0.1 kPa) compared with sites with lower VPDs (VPD effect = 15.3 [4.6]). Counts of M. lucifugus and E. fuscus also appeared higher where VPD was higher. In contrast, Perimyotis subflavus counts increased over time in relatively warm hibernacula and were unaffected by VPD. Where we manipulated hibernacula, we achieved cooling of on average 2.1 °C. At manipulated hibernacula, counts of M. lucifugus and P. subflavus increased over time (years since manipulation effect = 0.70 [0.28] and 0.51 [0.15], respectively). Further, there were more E. fuscus where cooling was greatest (temperature difference effect = –0.46 [SE 0.11]), and there was some evidence there were more P. subflavus in hibernacula sections that remained warm after manipulation. These data show bats are responding effectively to WNS through habitat selection. In M. lucifugus, M. septentrionalis, and possibly P. subflavus, this response is ongoing, with bats increasingly aggregating at suitable hibernacula, whereas E. fuscus remain in previously favored sites. Our results suggest that cooling warm sites receiving little use by bats is a viable strategy for combating WNS.