To better understand the detonation characteristics of ammonium nitrate (AN) and activated carbon (AC) mixtures, steel tube tests were carried out for AN/AC mixtures of various compositions and different forms of AN (powdered, prilled, phase stabilized and granular), and the detonation velocity was measured. The powdered AN/AC mixtures gave higher detonation velocities than the other AN forms. For all the AN/AC mixtures, the experimentally observed detonation velocities at each loading density were far below the theoretically predicted values calculated by the CHEETAH code based on thermohydrodynamics, exhibiting so-called non-ideal detonation. The lowest detonation velocity of powdered AN/AC mixtures was obtained as D=1.25 km/s for an AC content of 0.1 wt%. This was considered to be close to the critical condition for stable detonation. 相似文献
Ashes from sewage sludge incineration have a high phosphorus content, approximately 8% (W/W), which indicates a potential
resource of the limiting nutrient. Incineration of sewage sludge with subsequent recovery of phosphorus is a relatively new sludge
treatment technique. In this article, the leaching of phosphorus by using sulfuric acid as well as hydrochloric acid by means of several
batch experiments was presented. At the same time a selective recovery of phosphorus by adsorption was also discussed. The e ects
of acid concentration, temperature and time on extraction were studied. The phosphorus leaching increased with the increase in acid
concentration and temperature. Kinetic studies showed that the complete leaching of phosphorus took place in less than 4 h. Selective
adsorption of phosphorus by using orange waste gel provided a hint for recovery of this natural resource, which eventually could meet
the ever-increasing requirement for phosphorus. The overall results indicated that the incinerated sewage sludge ash can be treated with
acid to e ciently recover phosphorus and thus can be considered a potentially renewable source of phosphorus. 相似文献
A doubling of the global food demand projected for the next 50 years poses a huge challenge for the sustainability of both
food production and global and local environments. Today’s agricultural technologies may be increasing productivity to meet
world food demand, but they may also be threatening agricultural ecosystems. For the global environment, agricultural systems
provide both sources and sinks of greenhouse gases (GHGs), which include carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). This paper addresses the importance of soil organic carbon (SOC) for agro-ecosystems and GHG uptake and emission in agriculture,
especially SOC changes associated with soil management. Soil management strategies have great potential to contribute to carbon
sequestration, since the carbon sink capacity of the world’s agricultural and degraded soil is 50–66% of the historic carbon
loss of 42–72 Pg (1 Pg=1015 g), although the actual carbon storage in cultivated soil may be smaller if climate changes lead to increasing mineralization.
The importance of SOC in agricultural soil is, however, not controversial, as SOC helps to sustain soil fertility and conserve
soil and water quality, and organic carbon compounds play a variety of roles in the nutrient, water, and biological cycles.
No-tillage practices, cover crop management, and manure application are recommended to enhance SOC storage and to contribute
to sustainable food production, which also improves soil quality. SOC sequestration could be increased at the expense of increasing
the amount of non-CO2 GHG emissions; however, soil testing, synchronized fertilization techniques, and optimum water control for flooding paddy
fields, among other things, can reduce these emissions. Since increasing SOC may also be able to mitigate some local environmental
problems, it will be necessary to have integrated soil management practices that are compatible with increasing SOM management
and controlling soil residual nutrients. Cover crops would be a critical tool for sustainable soil management because they
can scavenge soil residual nitrogen and their ecological functions can be utilized to establish an optimal nitrogen cycle.
In addition to developing soil management strategies for sustainable agro-ecosystems, some political and social approaches
will be needed, based on a common understanding that soil and agro-ecosystems are essential for a sustainable society. 相似文献
Journal of Material Cycles and Waste Management - Improving the solid-state digestion of food waste (FW) is important for recovering energy and utilizing the digested residue as fertilizer. Herein,... 相似文献
The first draft scenario toward net zero greenhouse gas (GHG) emissions by 2050 for the material cycles and waste management sector was presented by the Ministry of the Environment, Japan in August 2021. The details of the future GHG emission estimation used to create the draft scenario are described in this document. For multiple scenarios where more aggressive measures, such as carbon capture, utilization, and storage (CCUS), were included in addition to business-as-usual and the current policy continuity scenario, future GHG emissions were estimated as the sum of the products of activities and emission factors indicating changes in measures between scenarios. The estimation outcomes demonstrated that future GHG emissions from the solid waste management sector could be anticipated to be zero or even negative when material conversion to biomass, primarily for plastics, recycling to raw materials, and installation of CCUS at incineration facilities are assumed. Extensions of prior plans are not enough to reach the goal of net zero emissions, according to the measures necessary and the volume and pace of their implementation suggested in this study. Stakeholders should collaborate with great ambition.
Environmental Science and Pollution Research - In this study, nanoporous anodic film was produced by anodization of niobium, Nb in a fluoride ethylene glycol electrolyte. The effect of anodization... 相似文献