The physico-chemical characteristics of granulated sludge lead us to develop its use as a packing material in air biofiltration. Then, the aim of this study is to investigate the potential of unit systems packed with this support in terms of ammonia and hydrogen sulfide emissions treatment. Two laboratory scale pilot biofilters were used. A volumetric load of 680 g H2S m(-3) empty bed day(-1) and 85 g NH3 m(-3) empty bed day(-1) was applied for eight weeks to a unit called BGSn (column packed with granulated sludge and mainly supplied with hydrogen sulfide); a volumetric load of 170 g H2S m(-3) empty bed day(-1) and 340 g NH3 m(-3) empty bed day(-1) was applied for eight weeks to the other called BGNs (column packed with granulated sludge and mainly supplied with ammonia). Ammonia and hydrogen sulfide elimination occur in the biofilters simultaneously. The hydrogen sulphide and ammonia removal efficiencies reached are very high: 100% and 80% for BGSn; 100% and 80% for BGNs respectively. Hydrogen sulfide is oxidized into sulphate and sulfur. The ammonia oxidation products are nitrite and nitrate. The nitrogen error mass balance is high for BGSn (60%) and BGNs (36%). This result could be explained by the denitrification process which would have occurred in anaerobic zones. High percentages of ammonia or hydrogen sulfide are oxidized on the first half of the column. The oxidation of high amounts of hydrogen sulfide would involve some environmental stress on nitrifying bacterial growth and activity. 相似文献
Adaptive management is an approach to managing natural resources that emphasizes learning from the implementation of policies
and strategies. Adaptive management appears to offer a solution to the management gridlock caused by increasing complexity
and uncertainty. The concept of adaptive management has been embraced by natural resource managers worldwide, but there are
relatively few published examples of adaptive management in use. In this article, we explore two watershed management projects
in southeastern Australia to better understand the potential of adaptive management in regional scale programs through qualitative,
case study–based investigation. The program logic of one case implies the use of passive adaptive management, whereas the
second case claims to be based on active adaptive management. Data were created using participant observation, semistructured
interviews with individuals and groups, and document review. Using thematic content and metaphor analysis to explore the case
data, we found that each case was successful as an implementation project. However, the use of both passive and active adaptive
management was constrained by deeply entrenched social norms and institutional frameworks. We identified seven “imperatives”
that guided the behavior of project stakeholders, and that have consequences for the use of adaptive management. Reference
to recent evaluations of the Adaptive Management Areas of the Pacific Northwest of the United States suggests that some of
these imperatives and their consequences have broad applicability. The implications of our findings are discussed, and suggestions
for improving the outcomes of regional scale adaptive management are provided. 相似文献
Climate services entail providing timely and tailored climate information to end-users in order to facilitate and improve decision-making processes. Climate services are instrumental in socio-economic development and benefit substantially from interdisciplinary collaborations, particularly when including Early Career Researchers (ECRs). This commentary critically discusses deliberations from an interdisciplinary workshop involving ECRs from the United Kingdom and South Africa in 2017, to discuss issues in climate adaptation and climate services development in water resources, food security and agriculture. Outcomes from the discussions revolved around key issues somewhat marginalized within the broader climate service discourse. This commentary discusses what constitutes “effective” communication, framings (user framings, mental models, narratives, co-production) and ethical dimensions in developing climate services that can best serve end-users. It also reflects on how ECRs can help tackle these important thematic areas and advance the discourse on climate services. 相似文献
Environmental Science and Pollution Research - This paper presents the treatment of a nitrite-limited wastewater by partial nitrification/anammox process under different dissolved oxygen (DO)... 相似文献
Individuals are always sensitive to their relative standing in interpersonal comparison processes of leader–member exchanges (LMXs) in teams. Little research, however, has investigated whether coworkers with a higher LMX influence the emotional and behavioral reactions of individuals with a lower LMX in different dyads. Drawing on social comparison theory and the symbolic model of procedural justice (PJ) climate, we conducted 2 independent studies—an experimental study focusing on the self‐perceived upward LMX comparison (i.e., an individual perceives that a coworker's LMX is higher than the LMX that he or she has with the supervisor; N = 203; Study 1: American working adults) and a field survey study focusing on the other‐perceived downward LMX comparison (i.e., a coworker perceives that his or her own LMX is higher than the LMX that the individual has with the supervisor; N = 177; Study 2: Chinese software engineers). Results from these studies consistently revealed that a coworker's higher LMX elicits an individual's hostile emotions when the PJ climate is low but that this relationship is buffered when the PJ climate is high. Results of both studies also showed that the coworker's higher LMX arouses the individual to direct harmful behavior toward that coworker (via the individual's feelings of hostility) when the PJ climate is low but not when it is high. 相似文献
Objective: This work aims at investigating the influence of some front-end design parameters of a passenger vehicle on the behavior and damage occurring in the human lower limbs when impacted in an accident.
Methods: The analysis is carried out by means of finite element analysis using a generic car model for the vehicle and the lower limbs model for safety (LLMS) for the purpose of pedestrian safety. Considering the pedestrian standardized impact procedure (as in the 2003/12/EC Directive), a parametric analysis, through a design of experiments plan, was performed. Various material properties, bumper thickness, position of the higher and lower bumper beams, and position of pedestrian, were made variable in order to identify how they influence the injury occurrence. The injury prediction was evaluated from the knee lateral flexion, ligament elongation, and state of stress in the bone structure.
Results: The results highlighted that the offset between the higher and lower bumper beams is the most influential parameter affecting the knee ligament response. The influence is smaller or absent considering the other responses and the other considered parameters. The stiffness characteristics of the bumper are, instead, more notable on the tibia. Even if an optimal value of the variables could not be identified trends were detected, with the potential of indicating strategies for improvement.
Conclusions: The behavior of a vehicle front end in the impact against a pedestrian can be improved optimizing its design. The work indicates potential strategies for improvement. In this work, each parameter was changed independently one at a time; in future works, the interaction between the design parameters could be also investigated. Moreover, a similar parametric analysis can be carried out using a standard mechanical legform model in order to understand potential diversities or correlations between standard tools and human models. 相似文献
Regional Environmental Change - Mediterranean forests are found in the Mediterranean basin, California, the South African Cape Province, South and southwestern Australia and parts of Central Chile.... 相似文献
Copper (Cu) is an essential element to humans; however, exposure to elevated concentrations through occupational hazard and/or environmental means may be detrimental. This paper provides results of a cross-sectional study aimed to determine the prevalence of copper sulphate (CuSO4) use in South African traditional medicine by traditional health practitioners (THPs) and details the use thereof. A total of 201 THPs were enrolled from two main municipal areas of KwaZulu-Natal (South Africa). Information on demographic characteristics of THPs, reasons for using or not using CuSO4 as well as administration methods and age groups of recipients were collected. Of the 201 THPs interviewed, 145 (72 %) use CuSO4 for healing purposes. The use of CuSO4 was strongly associated with gender (p = 0.009) where the proportion of CuSO4 users was higher for female than male THPs. CuSO4 was reportedly administered to individuals of all ages, including infants and children. The main routes of administration were enema (n = 110; 76 %), oral (n = 40; 28 %) and use in bath (n = 40; 28 %). The reasons cited for use are diverse and included skin rashes (n = 43; 30 %), aches, pains and swelling (n = 38; 28 %) as well as sexually transmitted diseases (n = 28; 19 %). This study identified a high prevalence of THPs using CuSO4 for healing purposes. These findings support the need to regulate South African traditional medicine to safeguard the user. 相似文献