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Steen Jensby posted an update 1 week, 1 day ago
Directing to unwieldiness NOx emitted by the industry, the removal of NOx was implemented using yellow phosphorus (P4) emulsion and red mud slurry as composite absorbent. Where yellow phosphorus is considered to stimulate formation of the ecological ozone (O3) from O2, the oxidation of insoluble NO into water-soluble NOx species by O3, and the red mud as a pH buffer can be used to maintain the pH of the absorption liquid in a range that better absorbs NOx. NO is finally converted into NO2- and NO3-, whereas the yellow phosphorus is mainly PO43-. Single-factor influencing on the efficiency of denitration include the concentration of yellow phosphorus, reaction temperature, stirring intensity, gas flow rate, O2 content, and red mud solid-liquid ratio were investigated. Response surface methodology (RSM) was used to optimize the process parameters. It was indicated that the removal rate of NOx can reach 99.3% under the optimal conditions. Moreover, the possible denitration reaction mechanism was also discussed.Population growth, rapid urbanization, industrialization and economic development have led to the magnified municipal solid waste generation at an alarming rate on a global scale. Municipal solid waste seems to be an economically viable and attractive resource to produce green fuels through different waste-to-energy conversion routes. This paper reviews the different waste-to-energy technologies as well as thermochemical and biological conversion technologies for the valorization of municipal solid waste and diversion for recycling. The key waste-to-energy technologies discussed in this review include conventional thermal incineration and the modern hydrothermal incineration. The thermochemical treatments (e.g. pyrolysis, liquefaction and gasification) and biological treatments (e.g. S63845 anaerobic digestion and composting) are also elaborated for the transformation of solid wastes to biofuel products. The current status of municipal solid waste management for effective disposal and diversion along with the opportunities and challenges has been comprehensively reviewed. The merits and technical challenges of the waste-to-energy technologies are systematically discussed to promote the diversion of solid wastes from landfill disposal to biorefineries.The cement-based solidification/stabilization is commonly used to remediate heavy-metal-contaminated clayey soils. The major problem associated with this method is heavy-metal precipitation, which retards cement hydration. The objectives of this paper are to study the influence of pH-dependent lead solubility patterns on the solidification/stabilization of contaminated smectite and to overcome the problems associated with cement hydration in this process through NaOH treatment. A series of physicochemical experiments were performed on untreated and NaOH-enhanced samples. Contaminated smectite with 5-100 cmol/kg-soil of lead nitrate was solidified/stabilized by 10-50% cement. This research demonstrates that solidification/stabilization is a pH-dependent phenomenon. Enhancement increases the pH of contaminated soil in which lead components transfer to a soluble form. Hereafter, as the results of XRD reveal, a decrease in lead precipitation on cement components is observed. Consequently, a noticeable increase in CSH formation is detected. The capsulation of lead ions by CSH improves the setting-time and unconfined compressive strength of solidified/stabilized samples. Furthermore, the TCLP results show a significant reduction in samples’ lead-leaching abilities. Therefore, enhancement has changed the governing retention phenomena from precipitation/stabilization in lead carbonate form to mainly capsulation/solidification by CSH. Moreover, the results show a noticeable reduction in the required cement content.Though commonly used in the dewatering of textile dyeing sludge (TDS) before its incineration, chemical conditioning has yet to be evaluated in terms of its impact on the reaction mechanisms, emissions, and ash minerals. This study combined experiments and equilibrium simulations to disentangle the interaction mechanism among the combustion behaviors, gas emissions, ash minerals of TDS conditioned with(out) three blend ratios of the AlCl3 conditioner. The use of the AlCl3 conditioner slightly improved the performance of the combustion stage of volatiles and chars. No significant effect of AlCl3 conditioner was detected on the kinetic mechanism of its main combustion stage best elucidated by the nth-order and diffusion models. SO2 was the main evolved gas whose reduction between 600 and 800 °C was attributed to its increased retention rate by CaO from the decomposition of CaCO3. Aluminum compounds acted as a stimulator in SO2 emission between 800 and 1000 °C since the formation of calcium aluminosilicates. At above 1060 °C, CaSO4 decomposed rapidly, thus almost completely releasing inorganic S. This study supplies new insights into pollution `controls on the combustion of TDS conditioned with Al salt coagulant.Lead-halide perovskite nanocrystals (NCs) are limited in commercial applications due to their high lead content. Developing lead-free perovskite NCs becomes a new choice. Among them, the tin-halide perovskite NCs exhibit the excellent photoelectric conversion efficiency, but has worse stability. Herein we describe an effective approach to the preparation of highly-stable all-inorganic tin-based perovskite NCs by using gelatin via interfacial passivation and coating, which leads to the retention of 77.46% of photoluminescence intensity even after the dispersion of the NCs in water for 3 d. The results show that gelatin form a “rich ligand” state on NC surface, such as amino-Sn, carboxylate-Sn and halogen-ammonium hydrogen-bonding interactions. The amino-Sn coordination would be replaced by carboxylate-Sn coordination when NCs are dispersed in polar-media. Meanwhile, gelatin is imparted excellent anti-mildew properties by NCs, which ensures long-lasting effect to NCs. This will promote the stability and sustainable development of the perovskite device.Microplastics (MPs) are a class of emerging contaminants with diverse sizes. They influence the behavior of pollutants in the environment and cause harmful effects on organisms. To date, the size effects of MPs on the accumulation of organic pollutants by terrestrial invertebrates remain unclear. Here, we study the impacts and mechanisms of polystyrene MPs on the accumulation and elimination of phenanthrene in earthworms. Results showed that larger-size MPs (10 and 100 µm) facilitated the accumulation of phenanthrene by earthworms in the first week, whereas 100 nm MPs inhibited the elimination of phenanthrene in earthworms afterwards. Higher genotoxicity to earthworms was observed for co-exposure of micron-size MPs and phenanthrene, and 10 µm MPs were detected at the highest concentration and caused the most serious DNA damage to earthworm coelomocytes. Biomarkers and their mRNA gene expression levels suggested that larger-size MPs caused severer damage to earthworms, thus leading to increased accumulation of phenanthrene by earthworms at the beginning.