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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.

Radioactive contamination caused by nuclear leakage accidents and radioactive source diffusion accidents will pose a threat to the environment and public safety. In order to remove the contamination, an emergency decontamination technique based on strippable coating was studied. The strippable coating takes acrylate emulsion as the main film forming agent and lauryl sodium sulphate as surfactant. The decontamination performance and application dosage of the coating were tested. At the application dosage of 2.5 kg m−2, the single decontamination rate reached 92.26% for uranium dust on concrete surface, which indicates this technology is a promising method for engineering decontamination.

A three-dimensional hollow NiCo

An in-plane and out-of-plane 2-axis resonator is required for a roll/pitch rate integrating gyroscope (RIG), which is much more challenging in design and fabrication compared with an in-plane 2-axis resonator used in a yaw RIG. In this study, we propose a dynamically balanced out-of-plane resonator to increase the out-of-plane quality factor (Q-factor). A balanced dual-mass structure is designed to reduce the torque applied to the supporting substrate, and thus increase the Q-factor of the out-of-plane mode. Design optimization for frequency matching, reducing mechanical deformation and increasing Q-factor through finite element method (FEM) simulation has been demonstrated. Manufacturing method of the device employing Au-Au thermo-compression bonding has been developed. The fabricated resonator oscillated at around 4380 Hz after remove by using an externally stacked piezoelectric actuator and laser Doppler vibrometer (LDV).

Nanoscale zero-valent iron, named nano-Fe0, is a reagent used to degrade trichloroethylene in groundwater. However, the efficiency of nano-Fe0 is moderate due to issues of dispersion and reactivity. As an alternative we synthesized bentonite-supported nanoscale Fe/Ni bimetals, named bentonite-Fe/Ni, to test the degradation of trichloroethylene in the presence of Suwannee River humic acids, as a representative of natural organic matter. 0.1 mmol/L trichloroethylene was reacted with 0.5 g/L of nano-Fe0, bentonite-Fe, Fe/Ni, and bentonite-Fe/Ni nanoparticles. Results show first that without humic acids the reaction rate constants k obs were 0.0036/h for nano-Fe0, 0.0101/h for bentonite-Fe, 0.0984/h for Fe/Ni, and 0.181/h for bentonite-Fe/Ni. These findings show that bentonite-Fe/Ni is the most efficient reagent. Second, the addition of humic acids increased the rate constant from 0.178/h for 10 mg/L humic acids to 0.652/h for 40 mg/L humic acids, using the bentonite-Fe/Ni catalyst. This finding is explained by accelerated dechlorination by faster electron transfer induced by humic quinone moieties. Indeed, the use of 9, 10-anthraquinone-2, 6-disulfonate as a humic analogue gave similar results.

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.

This study characterized sludge from an anoxic baffled reactor (ABR) used to treat textile dyeing wastewater. The process was run over 150 days. On day 152, five sludge samples were collected from compartments 1–5 of the ABR and a set of captive tests was conducted to investigate their particle size distributions (PSDs), dye biosorption and biodegradation properties, and dehydrogenase activity (DHA). The results indicated that the PSD of the five sludge samples from the ABR were similar. Methylene blue biosorption to the sludge samples followed the pseudo-second-order kinetic model and the actual biosorption process was controlled by external and intraparticle diffusion, simultaneously. After the sludge samples were cultivated for 24 h, the acid red GR dye removal efficiencies were 59.5, 68.3, 76.4, 61.5, and 65.4%, respectively. Eliminating dye biosorption, the dye biodegradation efficiencies were only 38.8, 46.3, 52.6, 48.3, and 46.0%, respectively. Furthermore, the DHA values were 28.2, 45.3, 56.5, 41.0, and 35.0 µg TF mL−1 h−1, respectively, and the DHA variation was in accordance with the dye biodegradation efficiency variation.

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 ...

In this paper, the plasma spray technique was used to deposit coatings with reconstituted nanostructured Al 2 O 3 /TiO 2 powders. The abrasive wear resistance of the ceramic coatings was evaluated using diamond abrasives. The result showed that the abrasive wear resistance of the coatings produced using the nanostructured Al 2 O 3 /TiO 2 powders is greatly improved compared with the coating produced using the conventional Al 2 O 3 /TiO 2 powder (Metco 130). The highest abrasion resistance of the coating sprayed with nanostructured Al 2 O 3 /TiO 2 powder is about four times that of the coating sprayed with the conventional Al 2 O 3 /TiO 2 powder. Both as fabricated and after wear Al 2 O 3 /TiO 2 coatings were investigated by X-ray diffraction, SEM and indentation tests. The abrasive wear mechanism is also discussed.

An experiment was conducted in a batch reactor for a real printing and dyeing wastewater pretreatment using Fenton process in this study. The results showed that original pH, hydrogen peroxide concentration and ferrous sulfate concentration affected ORP value and pretreatment efficacy greatly. Under experimental conditions, the optimal original pH was 6.61, and the optimal hydrogen peroxide and ferrous sulfate concentrations were 1.50 and 0.75 g L−1, respectively. The relationship among ORP, original pH, hydrogen peroxide concentration, ferrous sulfate concentration, and color (COD or BOD5/COD) was established, which would be instructive in on-line monitoring and control of Fenton process using ORP. In addition, the effects of wastewater temperature and oxidation time on pretreatment efficacy were also investigated. With an increase of temperature, color and COD removal efficiencies and BOD5/COD ratio increased, and they were in proportion to the exponent of temperature reciprocal. Similarly, color and COD removal efficiencies increased with increasing oxidation time, and both color and COD removal obeyed the first-order kinetics. The BOD5/COD ratio could be expressed by a second-degree polynomial with respect to oxidation time, and the best biodegradability of wastewater was present at the oxidation time of 6.10 h.

The mechanism of phosphorus removal by iron-contactor process (PRICP) is illustrated from two aspects: metallic corrosion and phosphorus removal by ferric salt. Advances in PRICP are reviewed to shed some light on the research focus in the future for the sake of in-depth study and wide application.

In order to investigate the effect of different carbon resource on enrichment of polyphosphate accumulating organisms (PAO) from sediment samples as well as the effect of PAO on the cycle of phosphorus in lake sediments, sedimentary samples in Lake Taihu were taken and enriched through using four kinds of carbon sources (glucose, cellulose, sodium acetate and propionate) in laboratory-scale sequencing batch reactors (SBRs). The COD/P ratio in the feeding was 15:1. The cycle time was 24 h and consisted of feeding, anaerobic period, aerobic period settle/decant period. The hydraulic retention time was 48 h, and the solids retention time was controlled at approximately 20 days. The dissolved oxygen concentration in aerobic period was maintained at 2-3 mg/L using an pump, where air was supplied at a flow rate of about 1 L/min. The reactor was operated at 25°C with an initial pH of 7.5 ± 0.1. The results showed that the orthophosphate concentration increased at the anaerobic phase in four reactors more or less, and decreased at the aerobic phase, which confirmed that there existed polyphosphate accumulating organisms in sediments of Lake Taihu. While phosphorus release rate using propionate as single carbon resource was the highest, acetate and propionate as substrate were benefit for accumulation of PAO.

This study investigated phosphorus removal in the rivers inputting into Lake Taihu, Jiangsu Province. Ecological community properties of aquatic plants and algae in those rivers were surveyed with focus on diversity and density. The results showed that total phosphorus (TP) concentrations decreased along the runoff in the rivers, and the river with balanced algae community and integrated water plants ecological system had the ability of retention and decontamination of non-point source pollutant-phosphorus. The current velocity and water level also affected self-purification efficiency of the river. It seemed that the rivers inputting into Lake Taihu acted as natural protective screen for pollutants flowing into lake, and natural rivers could be explored for phosphorus removal.

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.

Phenanthrene is a typical polycyclic aromatic hydrocarbon (PAH) found in contaminated water. This study investigated physiological responses of four submerged macrophytes to phenanthrene stress with time, following 40-day exposure to two concentrations of phenanthrene solutions in an outdoor-simulated experiment. A number of parameters including malondialdehyde, soluble carbohydrate and soluble protein contents were monitored. Results showed that the concentrations of phenanthrene in solution decreased obviously with duration of exposure. Subsequently, these four submerged macrophytes could recovered, although several days of phenanthrene exposure resulted in some adverse effects on these plants such as increased malondialdehyde and water soluble protein contents as well as reduced water soluble carbohydrate contents. Changes of these physiological parameters in these submerged macrophytes reflected their continuous tolerance to phenanthrene.

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.

A bulk mass transfer coefficient (BMTC) equation was derived from the mechanism of mass transfer in surface liquid membrane in this study, which was based on the analysis of biosorption process, conservation of mass in sludge granule and the unification of the dimension. A biosorption experiment was carried out in which anoxic sludge from an anoxic baffled reactor for printing and dyeing wastewater treatment was used to adsorb Acid Red GR dye. The results showed that there was a linear regression curve between ln[qe/(qe-q)] (qe and q were the amount adsorbed at equilibrium and at time t, respectively.) and time t. There was also a good agreement between the adsorbate amount measured and that predicted by the equation of BMTC. The BMTC of Acid Red GR dye adsorbed by anoxic sludge was 6.816 kgm(-3)min(-1). Experimental results indicated that the BMTC determined by a simple adsorptive experiment using this equation was credible. It could be a feasible and effective way to determine BMTC of activated sludge for biosorption performance.

A study of the treatment of printing and dyeing wastewater was carried out using the combined process of anoxic baffled reactor-biological contact oxidation. The results showed the pH ascended continuously and the oxidation-reduction potential dropped gradually from compartment 1-6 in ABR. When hydraulic retention time was 12h, color removal efficiency was 92% and the color of effluent of ABR could satisfy the professional emission standard (grade-1) of textile and dyeing industry of China. The total COD removal efficiency of the combined process was 86.6% and the COD of effluent could satisfy the professional emission standard (grade-2) of textile and dyeing industry of China.