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A three-dimensional hollow NiCo2O4 structure was successfully prepared with a precipitation-hydrothermal method. A balance between magnetic and dielectric losses was achieved by using a hollow NiCo2O4 structure loaded with benzotriazole (BTA), and thus the performance of electromagnetic waves was attenuated. The minimum reflection loss value of BTA@NiCo2O4 at 16.01 GHz was −35.39 dB when the absorber thickness was 2 mm, at which the absorption bandwidth for an RL of less than −10 dB is as high as 4.64 GHz. The absorption mechanism was characterized by the synergy among interfacial polarization, multiple reflection, and dipole polarization enhancement between NiCo2O4 and BTA. Interestingly, the epoxy/BTA@NiCo2O4 coating not only exhibited an outstanding microwave absorption (MA) performance but also has excellent anticorrosion and self-healing properties, as shown by the results of electrochemical impedance spectroscopy and confocal laser scanning microscopy. This work would be very helpful to the development of novel coatings with excellent MA performance and anticorrosion and self-healing properties.

A three-dimensional hollow NiCo

In this work, the occurrence and removal of polycyclic aromatic hydrocarbons (PAHs) were investigated in a combination process of anoxic baffled reactor (ABR)-hybrid coagulation/membrane bioreactor (HCMBR) for real textile dyeing wastewater treatment. It was found that the target compounds except for the chrysene, benzo(b)fluoranthene, dibenzo(a,h)anthracene, and benzo(g,hi)perylene occurred widely in raw textile dyeing wastewater, treated effluent and sludge samples. In the raw wastewater, two-ring naphthalene was the dominant compound, while three-ring PAHs predominated in the final effluent. The dominant compounds in the raw sludge samples were phenanthrene, while they were pyrene and indeno(1,2,3-cd)pyrene for final discharge sludge. The combination process achieved over 88% removal for all the PAHs. Low molecular weight (LMW) PAHs might be mainly removed by volatilization, adsorption, and sedimentation in the ABR treatment unit. High molecular weight (HMW) PAHs might be mainly removed by adso...

In this paper, we investigated the kinetics and thermodynamics of phosphorus adsorption by a new efficient phosphorus removal composite (EPRC). Kinetic analysis showed that the adsorption of phosphorus by EPRC is best described by a pseudo-first-order equation. Thermodynamic analysis showed that the Gibbs free energy (ΔG°) is negative, implying that the reaction is spontaneous. Moreover, the change in enthalpy (ΔH°) of phosphorus adsorption by EPRC was always greater than 60 kJ/mol, indicating that the adsorption was an endothermic chemical process. Furthermore, EPRC adsorbs phosphorus better at higher temperatures.

Six horizontal subsurface-flow constructed wetlands were operated year round at a wastewater treatment plant (WWTP) in Nanjing, China, to investigate the influence of temperature on nitrogen removal, micro-environment and plant eco-physiological characteristics. The data obtained showed that the removal rates of DON, NH4+-N and TN were significantly temperature-dependent. The substrate ureases activity and microbial nitrification intensity dropped as temperature decreased. Urease activity and nitrification intensity in planted wetlands were distinctly higher than that in unplanted wetlands. DO concentration in mid- and upper-layer of the wetlands had greater seasonal variation than that in bottom-layer. The net photosynthetic rate and evaporation rate of reeds were both significantly positively correlated to temperature. Consequently, in order to obtain more consistent year round nutrient removal, it is suggested that some appropriate heat-preservation measures are used to cover the surface of the wetlands, cold resistant plants that are active year round, and enhanced aeration in mid- and upper layer should be adopted.

In this work the performance of a hybrid coagulation/membrane bioreactor (HCMBR) was assessed for real textile dyeing wastewater advanced treatment. Poly-aluminum chloride (PACl) was selected and used in the experiments. Batch experiment results showed that the optimal dosage was 40 mg Al/L. During the pilot-scale experiment, the suitable dosage and dosing interval were once per day at the dosage of 40 mg Al per L of amount of mixed liquor into the HCMBR system. It was found that membrane fouling was effectively retarded by PACl addition in the running MBR system. Additionally, removal of pollutants according to influent and effluent quality was monitored. HCMBR achieved much higher removal efficiencies than membrane bioreactor (MBR) in CODcr, UV254, and total phosphate, due to PACl coagulation in the HCMBR bioreactor. And the application of PACl was effective in decreasing the content of extracellular polymeric substances and the membrane fouling resistances. The transmembrane pressure of HCMBR ...

A pilot-scale combination process of anoxic baffled reactor -hybrid membrane bioreactor for the real textile dyeing wastewater treatment was investigated. Anoxic baffled reactor as a hydrolysis process pre-treatment was performed well, which achieved 35.6 % COD removal efficiency when hydraulic retention time (HRT) was 16 h. The total COD removal efficiency of the combined process was 83.8 %. GC-MS analysis results demonstrated that the main component of raw influent was alkanes including 13 types. After hydrolysis process, the types of alkanes decreased to 5. In subsequent aerobic treatment phase, alkanes of supernatant of HMBR increased to 19, but total organic compounds category decreased to 24. New intermediate CholestaN-3β-ol production demonstrated that some complicated structures or large molecules substances in raw wastewater could be decomposed. GC-MS quantitative analysis results further showed that some toxic and hazardous substances, such as toluene, styrene, 1,2-dichlorobenzene were still in the final effluent. However toxic compounds e.g. phenols could be removed in the subsequent aerobic process. Therefore, most organic pollutants could be removed using the combined process. There were still some amounts of toxic compounds present in the final effluent.

A pilot-scale hybrid coagulation/membrane bioreactor (HCMBR) was investigated for real textile dyeing wastewater advanced treatment. Poly-aluminum chloride (PACI) was selected and used in the experiments. The HCMBR performed well in the removal of organic matter and total phosphate (TP). As compared to membrane bioreactor (MBR), HCMBR achieved much higher removal efficiencies in CODcr, UV 254 and TP, due to PACI coagulation in the bioreactor. In light of relative hydrophobicity and extracellular polymeric substances (EPS) content variation, the results indicated that EPS was a significant factor affecting membrane fouling. The trans-membrane pressure (TMP) of HCMBR developed much slower than that of MBR, which revealed that coagulation with PACI in the membrane bioreactor could alleviate membrane fouling. PACI addition was practically feasible for real textile dyeing wastewater advanced treatment without large excess sludge production. Based on above results, HCMBR is being considered to be technically and economically promising combination for real textile dyeing wastewater advanced treatment.

A new method of tailoring stimulated Brillouin scattering (SBS) gain spectrum for slow light propagation is proposed by use of two Gaussian-shaped broadband pump beams with different powers and spectral widths. The central frequency interval between the two pump beams are carefully set to be two inherent Brillouin frequency shift, ensuring that the gain spectrum of one pump has the same central frequency with the loss spectrum of the other one. Different gain profiles are obtained and analyzed. Among them a special gain profile is found that ensures a zero-broadening of the signal pulse independent of the Brillouin gain. This is owing to the compensation between the positive gain-dependent broadening and the negative GVD (group velocity dispersion) dependent broadening. The relationship of two pump beams is also found for constructing such a gain profile. It provides us a new idea of managing the broadening of SBS-based slow pulse by artificially constructing and optimizing the profile of gain spectrum.