When disposed in dumps or open landfills, waste degrades in aerobic conditions generating higher CO2 emissions and lower methane emissions. Improving waste management and extending access to waste collection will result in more waste being disposed in managed landfills. Sanitary landfills offer conditions favourable for Z-FA-FMK degradation. This leads to higher LFG generation and potentially more GHG emissions from landfills that can be reduced through LFG collection and utilisation for energy purposes, with better impacts on the environment, health and energy supply.
4.2.2. Waste management services in Africa: options and challenges
In principle, several practices are possible for MSW management, which includes waste reduction, recycling and recovery, and for energy recovery from waste . Several technologies are commercially available for energy recovery from waste, such as incineration, biochemical conversion (e.g. anaerobic digestion), which can bring other additional benefits (e.g. fertiliser from anaerobic digestion) and LFG collection. Some technologies entail certain technical and economic difficulties (incineration) or are still not proven at the commercial scale (gasification, pyrolysis). All those options need dedicated supply chain management to be set up at local level and some pathways for Africa, all relevant from both the technological and economical point of view, are shown in Fig. 2.
Finally, from the economic side, what emerges from the literature is that Bleomycin Sulfate the profitability of investments related to the construction of PV recycling facilities seems to be guaranteed only by the management of great amounts of wastes. The authors decided to analyse the Italian context with the aim to assess if the presence of current low volumes and the expectation of great volumes in the next future can support (or not) the development of a national PV panels recycling chain.
The paper is organized as follows: Section 2 presents a literature analysis about PV panels recycling with a technological, environmental and economic perspective. Section 3 focuses on the Italian market, by calculating the amount of wastes to be recovered under a high uncertainty. This way, gastroesophageal sphincter is possible to define the number of plants to be constructed in function of the selected optimal size. Section 4 presents an economic model developed and used to evaluate four case studies investments assumed with respect to two different installation sizes (185 ton and 1480 ton) and two different scenarios (PV manufacturer coincides or not with the PV recycler). Results are presented and discussed in Section 5. Additionally, a sensitivity analysis on some critical variables is conducted. Section 6 presents concluding remarks and future perspectives.
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Ionic liquids; Thermal stability; Decomposition mechanism; Amino acid; Quantum chemistry; Activation energy
Since the 1980s, interest has enormously grown in the room-temperature ionic liquids (RTILs), which are ideal reaction solvents, extraction solvents, electrolyte materials, and so on. The advantages of using amino acids are their low cost, biodegradability, biological acceptable, nontoxic and pharmaceutically acceptable, novel RTILs have been developed by focusing on the amino acids , , ,  and . Amino PSI-6206 ionic liquids (AAILs) have the potential to be applied in a wide range of scientific and industrial areas  and . Amino acid ionic liquids may also be biodegradable ionic liquids depending on the cation structure partner .
Decomposition temperature (Td) is another important property of the ionic liquids which make them different from the industrial applications views. Earlier, many amino acid ionic liquids, containing 1-alkyl-3-methylimidazolium(Cnmim), tetraalkylammonium(Nn n n n) and tetraalkylphosphonium(Pn n n n) cations, have been synthesized and their properties such as thermal decomposition have been reported. For a given anion, the Td of a series of amino acid ionic liquids is increased in the following order: ,  and Nnnnn<Cnmim<Pnnnn.
Punith and Seetharamappa  have reported that LY3009104 for any system, the possible mechanism of quenching can be static, dynamic or both. Dynamic and static quenching could be distinguished based on their differing dependence on temperature. For this, we have carried out quenching studies at different temperatures (298.15, 303.15 and 310.15 K). The data have also been analyzed using the Stern–Volmer equationequation(2)F0F=1+kq/τ0Q=1+KsvQwhere F0 and F are the intensities in the absence and presence of quencher [Q]. Ksv, the binding constant was obtained from the plot of F0/F vs. [Q]. With increase in temperature, the value of Ksv decreased for all the systems. The decreased Ksv values with increase in temperature reveal the presence of static quenching of proteins in the NEm . The value of τ0 for biopolymers is 10− 8 s and therefore, the value of kq for curcumin–protein would be of the order of 1012 M− 1 s− 1. Since the value is greater than 2 × 1010 M− 1 s− 1, the process is static in nature.
It can be found from the KW 2449 between Figs. 6 and 7 that water–cement ratio has a crucial influence on pore structure. With the increase of water–cement ratio, the surface tensile force of cement paste decreases so that pores are damaged seriously. Comparison of Figs. 6 and 7, when the water–cement ratio increased from 0.8 to 0.90, the pores are damaged obviously and the uniformity of pore size also decreased significantly. The pore structure is a key factor to affect the properties of cement-based foam material, including pore sizes, pore shape and pore connection, etc. The analysis shows that pore structure is influenced by the setting time of the cement paste and the stability of foam in cement paste. The variation in water–cement ratio has changed the consistence of cement paste, whereby affecting the cement paste setting time and foam curing speed. HPMC admixture could improve the flexibility and mechanical strength of the cement paste liquid film so that it is favorable for improving pore structure too.
The published electrochemical experiments that previously linked reduced NR with NAD+ ITF 2357 used a high potential drop (2000 mV) to reduce the NR without controlling the working electrode potential with a potentiostat (Jeon et al., 2012; Park and Zeikus, 1999). In addition, the solutions may have not been pre-reduced before adding NAD+. Because neutral red is known to undergo multiple redox reactions, cyclic voltammetry was performed with a large potential window (−1200 to +500 mVAg/AgCl) to determine which species may have been responsible for NAD+ reduction. While performing the scans on a phosphate buffered neutral red solution, two cathodic peaks with corresponding anodic peaks were observed (Fig. 1A). The first peak is the most commonly discussed reversible peak, which had a midpoint potential of −504 mVAg/AgCl and a cathodic peak voltage (Vpc) of −566 mVAg/AgCl. This measured midpoint potential is within 9 mV of the published value for neutral red at pH 6.0 ( Fig. S1). The second peak had a more positive midpoint potential of −346 mVAg/AgCl, but with a much larger overpotential, demonstrated by the Vpc of −909 mVAg/AgCl. This second reduction peak was noted by Halliday and Matthews (1983), but has received little attention in the recent literature. Constant polarization on the cathodic side of both peaks (−650 mVAg/AgCl and −950 mVAg/AgCl) yielded two solutions with different optical absorbance spectra ( Fig. 1B). The two molecules that give rise to these spectra are referred to in this work as NRH2 and NR−950, respectively.
Digester performance and process RO4929097 without and with supplementation of microelements and sulfate.ParameterUnita.1a.2Operation periodDay100–132 (33 days)187–225 (38 days)HRTDays1515OLRkg-COD/m3/d8.5 ± 0.488.2 ± 0.66Biogas productionL/L-digester/dunstable2.33 ± 0.14CH4%59 ± 0.1260 ± 0.82CO2%41 ± 1.4140 ± 0.88H2ppm402 ± 48.1385 ± 39.2EffluentpH/7.22 ± 0.117.38 ± 0.13TANg/L0.84 ± 0.230.95 ± 0.04Bicarbonate alkalinity (PA)g/L2.12 ± 0.422.43 ± 0.47Total alkalinity (TA)g/L4.15 ± 0.594.39 ± 0.51Inter. alkalinity (IA)g/L2.03 ± 0.191.96 ± 0.08IA/PA ratio/0.98 ± 0.140.83 ± 0.15IA/TA ratio/0.49 ± 0.030.45 ± 0.04VFAeffluent (range)Acetic acidg/L0.11–1.000.12–0.40Propionic acidg/L0.76–2.090.86–1.99Iso-butyric acidg/L0.14–0.400.09–0.41Butyric acidg/L0.07–0.08?0.14–0.24?Iso-valeric acidg/L0.14–0.380.10–0.43Valeric acidg/L0.10–0.210.16–0.44Total VFAg/L2.07–2.931.34–2.78TS removal%44 ± 3.6644 ± 4.10VS removal%49 ± 4.4349 ± 4.36COD removal%54 ± 2.2853 ± 3.05Biogas conv. efficiency%40 ± 4.6844 ± 2.94Hydrolysis%46 ± 5.6351 ± 3.67Acidogenesis%41 ± 5.1846 ± 3.39Methanogenesis%40 ± 4.6844 ± 2.94a.1: without supplementation of inheritance of acquired characteristics microelements and sulfate.a.2: with supplementation of microelements and sulfate.?Rarely detected.Full-size tableTable optionsView in workspaceDownload as CSV