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Landfill leachate nanofiltration concentrate after ultrafiltration was treated. The experiments were carried out in an electrolytic cell which had an anode chamber and a cathode chamber and could be separated by a proton exchange membrane. Different electrochemical processes combined with peroxydisulfate/Fe3+ (PS/Fe3+) were compared and the reactions in anode chamber and cathode chamber were discussed. The Anode/PS/Fe3+-Cathode/PS/Fe3+ process shows the best effect on COD removal and color removal. The 3D-EEMFS results indicate that Anode/PS/Fe3+-Cathode/PS/Fe3+ process has the best effect on the destruction of organics. In anode chamber, the total COD removal is ascribed to (1) the oxidation by SO4 − produced from PS activation by original metal ions in the target solution, (2) direct and indirect oxidations by anode, and (3) coagulation caused by Fe3+ after pH adjustment. In cathode chamber, the total COD removal is due to (1) the oxidation by SO4 − produced from PS activation by the regenerated Fe2+ from Fe3+ reduction on cathode, and (2) coagulation caused by Fe3+ after pH adjustment. An optimal experimental condition with current of 80 mA, Fe3+ dosage of 15 mM and PS dosage of 37.5 mM is obtained for Anode/PS/Fe3+-Cathode/PS/Fe3+ process. The energy consumption between Anode/PS/Fe3+-Cathode/PS/Fe3+ (4.42 kWh/kgCOD) and (Anode + Cathode)/PS/Fe3+ (4.57 kWh/kgCOD) is similar when 55% of COD is removed. However, the toxicity increase in Anode/PS/Fe3+-Cathode/PS/Fe3+ process is obviously less than that in (Anode + Cathode)/PS/Fe3+ process.

HESS J1640-465 is an extended TeV $\gamma$-ray source and its $\gamma$-ray emission whether from the shell of a supernova remnant (SNR) or a pulsar wind nebula (PWN) is still under debate. We reanalyze the GeV $\gamma$-ray data in the field of HESS J1640-465 using eight years of Pass 8 data recorded by the Fermi Large Area Telescope. An extended GeV $\gamma$-ray source positionally coincident with HESS J1640-465 is found. Its photon spectrum can be described by a power-law with an index of $1.42\pm0.19$ in the energy range of 10-500 GeV, and smoothly connects with the TeV spectrum of HESS J1640-465. The broadband spectrum of HESS J1640-465 can be well fit by a leptonic model with a broken power-law spectrum of electrons with an exponential cut-off at $\sim$ 300 TeV. The spectral properties of HESS J1640-465 are broadly consistent with the characteristics of other sources identified as PWNe, such as the correlations between high-energy luminosity ratios and the physical parameters of pulsar, including spin-down luminosity $\dot{E}$ and characteristic age $\tau_c$. All these pieces of evidence support that the $\gamma$-ray emission of HESS J1640-465 may originate from the PWN powered by PSR J1640-4631 rather than the shell of the SNR G338.3-0.0., Comment: 10 pages, 6 figures, 3 tables. Accepted by ApJ

We report the detection of GeV $\gamma$-ray emission from supernova remnant HESS J1731-347 using 9 years of {\it Fermi} Large Area Telescope data. We find a slightly extended GeV source in the direction of HESS J1731-347. The spectrum above 1 GeV can be fitted by a power-law with an index of $\Gamma = 1.77\pm0.14$, and the GeV spectrum connects smoothly with the TeV spectrum of HESS J1731-347. Either a hadronic-leptonic or a pure leptonic model can fit the multi-wavelength spectral energy distribution of the source. However, the hard GeV $\gamma$-ray spectrum is more naturally produced in a leptonic (inverse Compton scattering) scenario, under the framework of diffusive shock acceleration. We also searched for the GeV $\gamma$-ray emission from the nearby TeV source HESS J1729-345. No significant GeV $\gamma$-ray emission is found, and upper limits are derived., Comment: 6 pages, 5 figures, 3 tables. Accepted for publication in ApJ

We report the detection of a GeV $\gamma$-ray source which is spatially overlapping and thus very likely associated with the unidentified very-high-energy (VHE) $\gamma$-ray source HESS J1427-608 with the Pass 8 data recorded by the Fermi Large Area Telescope. The photon spectrum of this source is best described by a power-law with an index of $1.85\pm0.17$ in the energy range of $3-500$ GeV, and the measured flux connects smoothly with that of HESS J1427-608 at a few hundred GeV. This source shows no significant extension and time variation. The broadband GeV-TeV emission over four decades of energies can be well fitted by a single power-law function with an index of 2.0, without obvious indication of spectral cutoff toward high energies. Such a result implies that HESS J1427-608 may be a PeV particle accelerator. We discuss possible nature of HESS J1427-608 according to the multi-wavelength spectral fittings. Given the relatively large errors, either a leptonic or a hadronic model can explain the multi-wavelength data from radio to VHE $\gamma$-rays. The inferred magnetic field strength is a few $\mu$G, which is smaller than typical values of supernova remnants (SNRs), and is consistent with some pulsar wind nebulae (PWNe). On the other hand, the flat $\gamma$-ray spectrum is slightly different from typical PWNe but similar to that of some known SNRs., Comment: 8 pages, 8 figures, 2 tables, Accepted for publication in ApJ

Puppis A is a very famous and extensively studied supernova remnant (SNR) that shows strong evidence of shock-cloud interaction. We re-analyze the GeV $\gamma$-ray emission of it using seven years Pass 8 data recorded by the Fermi Large Area Telescope (Fermi-LAT). The morphology of the $\gamma$-ray emission is more compatible with that of the thermal X-ray and IR emissions than the radio image, which suggests a possible correlation between the gamma-ray emitting region and dense clouds. The $\gamma$-ray spectrum in the energy range of 1-500 GeV shows a break at $7.92\pm1.91$ GeV with the photon indices of $1.81\pm0.08$ below the break and $2.53\pm0.12$ above the break, which can naturally explain the lack of TeV $\gamma$-ray emission from Puppis A. The multi-wavelength observations favor a hadronic origin for the $\gamma$-ray emission.