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Translocation and delivery of pesticides onto the molecular target is often a limiting step of efficacy, causing excessive use of pesticides and adverse effects on the environment and human health. Advances of nanomaterials have opened up a new avenue for effective translocation and delivery to increase the pesticide efficacy and reduce risks. We successfully synthesized and fully characterized a mesoporous silica nanoparticle-based mitochondria-targeted pesticide nanocarrier for the oxidative phosphorylation and ATP synthesis disruptor chlorfenapyr (Chl). The nanocarriers can be readily absorbed orally and translocated into the midgut and Malpighian duct of Spodoptera frugiperdalarvae and target mitochondria at the subcellular level. The Chl loading content on the nanocarrier was up to 35%. The toxicity of the Chl nanocarriers to the 3rd instar S. frugiperdalarvae (half-maximum lethal concentration (LC50), 16.4 μg g−1expressed by the Chl content) was almost doubled relative to Chl alone (LC50= 30.1 μg g−1). Further research showed that the mitochondria-targeted nanocarrier enhanced Chl efficacy by inducing mitochondrial damage in Sf9 cells, which led to the collapse of the mitochondrial membrane potential and reduction of ATP production. The mitochondria-targeted nanocarriers have great application potential in the formulation of oxidative phosphorylation and ATP synthesis disruptors, which can minimize their potential threats to food/environmental safety.

The present work demonstrated preparation of coal-based electrode materials (CEM)-derived low-rank coal for simultaneous removal of ammonia nitrogen (NH3-N) and chemical oxygen demand (COD) from coking wastewater by a three-dimensional electrode system (3DES). The influence of important parameters in 3DES such as processing time, applied voltage, electrode plate spacing, mass of commercially activated carbon (CAC), and initial pH were investigated. Based on the central composite design, the response surface method (RSM) was employed in order to optimize the variable parameters in removal process of pollutants. From the analysis of RSM, the optimum conditions for 3DES were 4.5 h of processing time, 5.5 V of applied voltage, 17 mm electrode plate spacing, 4.5 g CAC, and pH of 3 with higher simultaneous removal rate of COD (74.20%) and NH3-N (51.48%). Besides, the content of N element (4.9%) and N containing groups were traced by SEM-EDS and FTIR analysis in order to verify the removal effect. The experiment results showed the capability of CEM for electrode system removal of pollutants from coking wastewater and obtained considerable simultaneous removal rate of NH3-N and COD.

The contamination of water resources by phenolic compounds (PCs) presents a significant environmental hazard, necessitating the development of novel materials and methodologies for effective mitigation. In this study, a metallic copper-doped zeolitic imidazolate framework was pyrolyzed and designated as Cu-NC-20 for the activation of peroxymonosulfate (PMS) to degrade phenol (PE). Cu-NC-20 could effectively address the issue of metal agglomeration while simultaneously diminishing copper dissolution during the activation of PMS reactions. The Cu-NC-20 catalyst exhibited a rapid degradation rate for PE across a broad pH range (3-9) and demonstrated high tolerance towards coexisting ions. According to scavenger experiments and electron paramagnetic resonance analysis, singlet oxygen (1O2) and high-valent copper-oxo (Cu(III)) were the predominant reactive oxygen species, indicating that the system was nonradical-dominated during the degradation process. The quantitative structure-activity relationship (QSAR) between the oxidation rate constants of various substituted phenols and Hammett constants was established. It indicated that the Cu-NC-20/PMS system had the optimal oxidation rate constant with σ−correlation and exhibited a typical electrophilic reaction pattern. This study provides a comprehensive understanding of the heterogeneous activation process for the selective removal of phenolic compounds.

Microwave pyrolysis technology used for the efficient and clean conversion of low-rank coal is of concern in this study. An efficient and cheap Fe2O3/bluecoke (Fe2O3/BC) absorber with a wrapped structure was prepared by the hydrothermal synthesis method using ferric nitrate nonahydrate (iron source), sodium hydroxide (precipitation agent), and CTAB (protective agent), and the effects of BC, Fe2O3, and Fe2O3/BC absorbers on microwave pyrolysis of low-rank coal were investigated through some analytic methods, such as scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), and gas chromatography–mass spectrometry (GC–MS). The pyrolysis temperature, yields, and characteristics of pyrolysis products (bluecoke, pyrolysis water, tar, and coal gas) were examined and compared to verify the effect of the Fe2O3/BC absorber. Results showed that the temperature increment rate was improved by these absorbers, and the highest temperature increment rate was obtained with the Fe2O3/BC absorber, followed by Fe2O3and BC absorbers. The yield of the liquid product (pyrolysis water and tar) obtained with the Fe2O3/BC absorber was the highest, arriving at 14.31 wt %, in which the yield and carbon content of tar were 6.54 and 20.40 wt %, respectively. The characteristics of the products indicated that all of these absorbers enhanced the catalytic cracking reactions of coal, but Fe2O3/BC performed the best among the studied absorbers. A synergistic effect that promoted liquefaction and inhibited coal gasification was exerted by Fe2O3and BC, and it may have been caused by the composite component and wrapped structure of the Fe2O3/BC absorber.

A simple chemical route was adopted for the preparation of adsorbent to remove fluoride in the simulation solution. In this study, commercially activated carbon (CAC) was used as the raw material, HNO3(20 wt%), La(NO3)3·2H2O (0.05 mol/L), and Al(NO3)3(0.10 mol/L) were employed as modification reagents to successfully prepare the CAC adsorbent loaded with the elements La and Al (La(iii)–Al(iii)–CAC). The modified adsorbent was characterized by scanning electron microscopy, energy-dispersive spectroscopy, and Fourier-transform infrared spectroscopy measurements. The effects of variables such as solution pH, adsorption time, initial concentrations, and volume of solution were investigated on adsorption efficiency by the response surface method (RSM). Under optimum conditions, specified as a pH value of 6, an adsorption time of 1.2 h, an initial concentration of 30 mg/L, a solution volume of 25 mL, and the value of RFcan reach at 74.11%. From the RSM analysis, the pH value was a significant factor in the adsorption process and the order for these key factors was as follows: pH > adsorption time > solution volume. Meanwhile, there were interactions among these factors. Chemical modification had an important role in pore structure generation and functional group of adsorbent to improve the adsorption efficiency. The removal performance of adsorbent on simulation solution of fluoride also showed the feasibility of adsorbent to be applied in industrial purposes.

Accurate evaluation of power losses in a modular multilevel converter (MMC) is very important for circuit component selection, cooling system design, and reliability analysis of power transmission systems. However, the existing converter valve loss calculation methods using the nearest level modulation (NLM) method and the traditional sorting-based capacitor voltage balancing strategy are inaccurate since the submodule (SM) switching logics in the MMC arms are uncertain. To solve this problem, the switching principle of the SMs in the sorting-based voltage balancing strategy is analyzed. An accurate MMC power loss calculation method based on the analysis of loss distribution of various SM topologies, including half-bridge submodule (HBSM), full-bridge submodule (FBSM) and clamp double submodule (CDSM), is proposed in this paper. The method can accurately calculate the losses caused by the extra switching actions during the capacitor voltage balancing process, thus greatly increasing the calculation accuracy of switching losses compared with existing methods. Simulation results based on a practical ± 350 kV/1000 MW MMC-HVDC system with variety of MMC topologies with different voltage balancing strategies demonstrate the effectiveness of the proposed method.

A cyanide tailings slurry electrolyte (CTSE) was treated using a synergistic extraction system (P204-T) composed of di(2-ethylhexyl)phosphate (P204, (C8H17O)2PO2H, H2A2), trioctylamine (TOA, ([CH3(CH2)7]3N), R3N), and iso-alkanes, and a collaborative extraction technique involving oxalic acid stripping and photocatalysis was developed to separate and recover valuable metals and prepare ferrous oxalate. The results show that at a pH of 1.5, the P204 concentration of 15 vol%, TOA concentration of 10 vol%, O/A of 1:1, an oscillation time of 10 min, and an oscillation frequency of 190 rpm, the single-stage Fe(III) and Zn(II) extraction efficiencies of P204-T were 99.25% and 99.02%, respectively, and the saturated extraction capacities were 25.01 g•L−1and 1.20 g•L−1, respectively. TOA destroyed the dimer structure of P204 and promoted the –OH bond and –OP group in P204 to combine with TOA through hydrogen bonding to form N–H+···O–P and N–H+···OP bonds, resulting in the R3NHA·(HA) composite structure. During the collaborative extraction process, ion exchange with FeSO4+resulted in the formation of FeSO4A·(HA)3and ion exchange with the intermediate product (R3NH)2SO4and Zn(SO4)22-formed (R3NH)2Zn(SO4)2, which improves the extraction efficiency of metal ions. In addition, some amount of P204 underwent ion exchange with free Fe3+and Zn2+to produce FeA3(HA)3and ZnA2(HA)2, respectively. At oxalic acid concentration of 1 mol•L−1, an O/A of 1:3, the efficiencies of Fe(III) and Zn(II) stripped from the saturated organic phase reached 99.65% and 99.41%. Zn(II) formed the ZnC2O4·2 H2O precipitate and Fe(III) separation. FeC2O4·2 H2O was successfully synthesized by ultraviolet photocatalysis using iron oxalate complex as the stock solution.

The cyanide gold extraction wastewater from a gold smelter was treated using a persulfate-electrochemical oxidation (PS-EO) coupling process. The optimal process conditions and significance level of each factor were determined using orthogonal experiments, and the precipitates and cathodic precipitates in the system were analyzed and characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope-energy dispersive spectroscopy (SEM-EDS), and the oxidation removal reaction mechanism of cyanide was further explored. The results showed that voltage, time and PS concentration were the main influencing factors of the cyanide removal extent. When the voltage was 5 V, PS concentration 0.5 g L–1, pH 7, plate spacing 2.5 cm and reaction time 240 min, the removal extents of total cyanide (CNT), free cyanide (CN–), Cu and Zn ions in wastewater reached 98.33 %, 100 %, 99.53 % and 98.86 %, respectively. The removal of cyanide was mainly attributed to the indirect oxidation by SO4•–, •OH and O2•–active radicals produced by activated PS and the direct oxidation of S2O82–. The contribution rate of S2O82–direct oxidation was 42.38 %. The oxidation contribution rates of SO4•–, •OH and O2•–active free radicals were 15.75 %, 29.33 % and 12.54 %, respectively. Compared with simple PS and EO treatment processes, the PS-EO combined process reduced the amount of oxidants and helped to improve the current density of the system, as well as the generation of active free radicals such as SO4•–, •OH and O2•–. Additionally, after PS-EO treatment, there were almost no precipitates such as Zn(CN)2, CuCN, Zn(OH)2and Cu(OH)2produced in the wastewater. The cyanide ions in complex ions such as Cu(CN)32–and Zn(CN)42–were completely oxidized to N2and CO2, and then under the influence of an electric field, the released Cu2+and Zn2+ions were directed to migrate to the cathode and precipitate.Finally, the treated wastewater could be directly returned to the grinding or leaching the ore process, thus achieving the goals of being harmless and utilizing cyanide wastewater resources.

Sewage sludge-derived mesoporous biochars (SS-MBCs) were prepared by using cationic polyacrylamide (PAM+) as a template agent through a template-like method under high temperature and employed for getting rid of methylene blue (MB) from water. Textural evolution, mesostructured morphology, thermodynamic properties, and surface chemical groups of SS-MBCs were analyzed. It showed that PAM+not only played an important role in good nucleation that brought well-developed texture and novel pore size distribution to SS-MBCs but also improved the MB adsorption capacities of SS-MBCs by increasing the specific surface area and the content of oxygen functional groups, especially the lactone. Preparation factor analysis indicated that PAM+concentration, dosage of additive sludge, and carbonization temperature had distinct effects on material structure and adsorption performance especially above the pyrolytic temperature of 800 °C. The adsorption kinetics and isotherms were analyzed in detail, and it revealed that the kinetics and equilibrium adsorptions of SS-MBCs could be well-described by the Langmuir isotherm model and pseudo-second-order kinetics, respectively. Remarkably, the SS-MBCs showed higher removal efficiency and adsorption capacity than commercial activated carbon and most reported sludge-based adsorbents.

Blue coke-based activated carbon (BAC) was prepared via CO2activation with disused blue coke powder as raw materials at high temperature. The factor of activation temperature was intensively studied. The properties of sample were characterized by N2adsorption-desorption techniques, scanning electron microscopy (SEM) and Fourier transform infrared (FTIR), and the activation mechanism was also proposed. The results showed that, with the increase of temperature, the yield of BAC decreased, while the iodine adsorption increased first and then decreased. The N2adsorption-desorption isotherms revealed that the BAC had both micropores and mesopores, and the optimal temperature of porosity development was at 900-1000°C. When the activation temperature reached 1000°C, the maximum Brunauer-Emmett-Teller (BET) specific surface area and pore volume of BAC were 636.91 m2·g-1and 0.3627 cm3·g-1, respectively. The FTIR results indicated that BAC surface contained large amounts of surface functional groups such as hydroxyl, ester, carboxyl, and so on. The content of them decreased with the increase of temperature. Mechanism analysis shows that radial hole-making function happen first then transverd hole-enlarging function as the temperature increases, for the formation of large amount of microporous, the radial activation was the main controlling process.

Custom design of JMP software was used to optimize the iodine number of coal-based electrode materials. Taking the additive ratio (A), heating rate (B) and final pyrolysis temperature (C) into account and the significance sequence was C>B>A. Set the additive ratio as 0.2, the heating rate as 5°C/min and the final temperature as 900°C, the iodine number was improved to 403.14 mg·g-1, and the compressive strength was 2.01 MPa. Surface morphology of the coal-based electrode materials were characterized by scanning electron microscopy (SEM). The functional group species were explored by Fourier infrared spectrophotometer (FTIR). Then applied the voltage of 4 V, coal-based adsorption materials were set as cathodes and anodes in a 3-dimensional electrode system with the commercial activated carbon as a particle electrode. After 5 h treatment for cyanide wastewater, the removal rate of most ions was achieved to 72% or more. It was the collaborative effect in the combined action of electro-adsorption and electrodeposition.

With the short supply of phosphorus (P) resources all over the world, more and more phosphorus-rich excess sludge is produced. In this study, a pharmaceutical surplus activated sludge was subjected to alkali and ultrasonic treatment to promote the release of phosphorus. The optimisation of phosphorus release from pharmaceutical surplus activated sludge by alkali and ultrasonic treatment was investigated. The response surface methodology was adopted to optimise the conditions for phosphorus and organic matter release. A quadratic model was established to describe phosphorus and organic matter release. The variance was analysed by using the Design-Expert software, and the optimum operation conditions were decided on. The results indicated that the quadratic model could well fit the relationship between the release of phosphate phosphorus (PO43−-P) and chemical oxygen demand (COD) and the influencing factors. The order of influence on the release of phosphate phosphorus and COD was as follows: pH > total solids > ultrasonic power > time. The maximum release of phosphate phosphorus was 15·3%.

In this study, activated carbon (AC) was prepared from municipal sludge with peanut shell as the carbon additive and the ferric chloride as activator. Then the properties of AC activated by ferric chloride (FAC) and non-activated (NAC) were analyzed. Main results show that FAC has extremely higher BET surface area (781.5 m2/g) and pore volume (0.859 m3/g) than NAC, which implies that ferric chloride can effectively promote the formation of developed pore structures of AC. Moreover, the obtained ACs were used as adsorbent to remove phenol in aqueous solution. Results indicate that FAC and NAC have a higher adsorption capacity in the range pH of 7–9 and 1 g/L is the most suitable dosage of AC, considering of the removal rate and adsorption capacity. The adsorption kinetic data and adsorption isotherm data are well described by the pseudo-second order model and Freundlich isotherm model. The maximum equilibrium adsorption capacity is 109.58 mg/g (1 g/L, pH 8.0, 298K). In summary, it is an effective method to prepare AC from sludge and a small amount of peanut shell by using ferric chloride as activator and to remove phenol. This provides a potential option for sludge resource recovery.

Urbanization is a potential factor in economic development, which is a main route to social development. As the scale of urbanization expands, the quality of the urban water environment may deteriorate, which can have a negative impact on sustainable urbanization. Therefore, a comprehensive understanding of the functions of the urban water environment is necessary, including its security, resources, ecology, landscape, culture, and economy. Furthermore, a deep analysis is required of the theoretical basis of the urban water environment, which is associated with geographical location, landscape ecology, and a low-carbon economy. In this paper, we expound the main principles for constructing a system for the urban water environment (including sustainable development, ecological priority, and regional differences), and suggest the content of an urban water environmental system. Such a system contains a natural water environment, an economic water environment, and a social water environment. The natural water environment is the base, an effective economic water environment is the focus, and a healthy social water environment is the essence of such a system. The construction of an urban water environment should rely on a comprehensive security system, complete scientific theory, and advanced technology.

A lab-scale hybrid membrane bioreactor-microbial fuel cell system (hMBR) and a single MBR system (sMBR) were compared to investigate the characteristics of membrane fouling and biopolymers. The results indicated that both MBRs had excellent performance in the removal of chemical oxygen demand (COD) and ammonia nitrogen. Although the general compositions of the extracellular polymeric substances (EPS) and the soluble microbial products (SMP) were very similar, the concentrations in the hMBR were lower. An X-ray analysis indicated that Ca, Mg, Si and Fe were prone to accumulate on the membrane surface in the sMBR. An excitation-emission matrix (EEM) analysis showed that more aromatic proteins (I and II) and fewer humic/fulvic acid-like substances were observed in the hMBR. Moreover, almost half of the total components of EPS and SMP were soluble microbial metabolites in the hMBR. In conclusion, the hybrid system could alleviate membrane fouling by influencing the characteristics of the biopolymers.

To improve pyrolysis efficiency and tar quality, the effects of different amounts of additional molybdenum disulfide (MoS2) on the microwave pyrolysis of low-rank coal under the circulating gas atmosphere were studied in a coal–gas microwave co-pyrolysis experimental apparatus via self-research and development. Coal–gas analyzer, X-ray diffraction, combined scanning electron microscopy and energy-dispersive spectrometry, Fourier transform infrared spectroscopy, and gas chromatography–mass spectrometry were all used to conduct analysis and characterization of the pyrolysis products. The experimental results showed that both the yield of liquid products and valuable component (H2+ CH4+ CO) in the gas increased initially and then decreased with the increase of MoS2. When the optimum addition ratio of 8.3% MoS2was selected, the yield of liquid products and light oil content were up to 28.4 and 67.55%, higher by 7.6 and 49.48% compared to those of non-MoS2, respectively. The gas heat value was up to 15.14 MJ/m3, and the contents of CH4, CO, and H2were 25.34, 31.51, and 22.19%, respectively. The valuable component content in the gas was up to 79.04%. The ash content in bluecoke (i.e., solid product) was higher by 11.23% compared to that of non-MoS2, and the n(H)/n(C) value increased by 0.8%. The contents of alkanes and single-ring aromatic compounds in the tar increased as well as the n(H)/n(C) values in each of the light, intermediate, and heavy components. It indicated that MoS2could effectively promote the hydrocracking of coal tar and improve the stability of tar.

Both cyclic and noncyclic scrubbing experiments were conducted to remove NO from simulated flue gas in a lab-scale countercurrent spraying reactor. The effects of various operating parameters (initial solution pH, NaClO concentration, absorbent temperature, and inlet NO and SO2concentrations) on NO removal efficiencies were investigated in the noncyclic scrubbing mode. The results showed that NO removal efficiency increased greatly with the decrease of the initial pH value. However, there was a drop in NO removal efficiency, possibly due to the NO2absorption in the gas phase. NO removal efficiency increased gradually with the increase of the NaClO concentration. Complete removal of NO was achieved when the NaClO concentration was 24 × 10–3mol·L–1. However, the NO removal efficiency obviously decreased with the absorbent temperature increasing from 303 to 343 K. This could be mainly ascribed to the decrease of the water solubility of NO2and the absorption reaction of NO2with water vapor. Furthermore, NO removal efficiency increased quickly with the increase of the inlet NO concentration. The coexisting SO2in the simulated flue gas had little effect on the NO removal efficiency. Both NO and SO2could be removed simultaneously with a SO2removal efficiency of 100% and a NO removal efficiency of >93%. More importantly, the results of cyclic scrubbing experiments indicated that an average NO removal efficiency of 74% had been obtained for the whole cyclic scrubbing duration. The utilization of NaClO oxidant was calculated to be approximately 83%. The ion chromatographic analysis showed that there was no ON2–in the spent liquor. The results demonstrate that NaClO is a low-cost high-efficiency oxidant for NO removal from exhaust gas and that it has great potential for industrial applications.

The simultaneous nitrogen and phosphorus removal performance of the Johannesburg-Sulfur autotrophic denitrification (JHB-SAD) system was investigated in this study. The results showed that the JHB-SAD system achieved maximum removal efficiencies of 86.5, 96.0, 96.4 and 90.7% for COD, TN, NH4+–N and TP, respectively, with average effluent concentrations of 27.7, 1.26, 0.99 and 0.18 mg L–1, respectively. These results indicate that the nutrients could be almost completely removed by the JHB-SAD system if NH4+–N was sufficiently oxidized and that the JHB-SAD system could be a promising alternative to remove nutrients from municipal wastewater with a low COD/TN ratio. Meanwhile, bacterial communities in the JHB-SAD system were investigated using high-throughput sequencing technology. Taxonomic analysis found that 8 abundant phyla in the JHB-SAD system accounted for 86.8–91.1% of the total effective sequences, which were Proteobacteria (34.7–57.5%), Bacteroidetes (11.7–23.4%), Planctomycetes (8.71–20.1%), Chloroflexi (3.08–9.42%), Firmicutes (1.83–3.00%), Verrucomicrobia (0.41–1.81%), Gemmatimonadetes (0.44–1.27%) and Chlorobi (0.30–1.05%). In addition, redundancy analysis (RDA) showed that the phyla Bacteroidetes, Chlorobi, and Firmicutes were related to COD, NH4+–N concentration and COD removal, and the phyla Gemmatimonadetes and Chloroflexi were related to the SO42–concentration in the SAD reactor due to autotrophic denitrification.

Efficient and sustainable recovery of precious metals from the acidic leaching solution of solid waste is considered to be the main solution to the scarcity of precious metal resources. In this study, a hydrophobic deep eutectic solvent (HDES) was synthesized using trioctylmethylammonium chloride (N263) and oleic acid (OA). HDES was then used for the efficient recovery of Ir, Pt, Ru, and Rh from leaching solution containing precious metals. The effects of different molar ratios between N263 and OA, the initial pH of the aqueous phase, the oscillation time, and the phase ratio O/A of the extraction process were investigated. The organic phases were characterized analytically using ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, and electrospray ionization–mass spectrometry to further investigate the reaction mechanisms of the extraction process. The single-stage extraction percentages of Ir(IV), Ru(III), Pt(IV), and Rh(III) ions were 97.57%, 94.26%, 99.55%, and 15.1%, respectively. The high saturation extraction capacity of HDES enabled a high precious metal load, reaching 18.44gL−1. Hydrogen bonds were formed between Cl-, which was bound by electrostatic force in the N263 structure, and H in the -COOH group in the OA molecule. During the extraction process, metal chloride complex ions replaced Cl-and entered the organic phase as 2[C17H33-COOH···N263+]IrCl62-, 3[C17H33-COOH···N263+]RuCl63-, 2[C17H33-COOH···N263+]PtCl62-, and 3[C17H33-COOH···N263+]RhCl63-. After scrubbing for effective removal of Cu and Fe in the loaded organic phase, different systems were used for stripping. The stripping percentage of precious metal ions reached more than 96.3%, providing efficient separation of the four precious metals from wastewater.

AbstractA novel system integrating Johannesburg (JHB) and sulfur autotrophic denitrification (SAD) process was proposed with the purpose of efficient removal of organic matter and nitrogen when treating low COD/TN ratio municipal wastewater. The characteristics and fate of dissolved organic matter in the Johannesburg-Sulfur autotrophic denitrification (JHB-SAD) system were investigated using excitation–emission matrix fluorescence spectroscopy with a parallel factor analysis. Three components were identified including tryptophan-like (component C1), tyrosine-like (component C2), and fulvic-like (component C3) materials. The tyrosine-like and tryptophan-like materials, which were more abundant than fulvic-like materials, were the dominant components of the raw municipal wastewater in Shenyang North Wastewater Treatment Plant. In the JHB-SAD system, the tyrosine-like and tryptophan-like materials were more efficiently removed than the fulvic-like materials, and the removal efficiencies of the three components were 80.8% (tryptophan-like materials), 72.5% (tyrosine-like materials), and 33.4% (fulvic-like materials), respectively. Furthermore, the removal performance of the three components varied in the different zones of the JHB-SAD system. The tryptophan-like and fulvic-like materials were removed in the pre-anoxic, anaerobic, and aerobic zones. The tyrosine-like materials were mainly degraded in the anoxic and aerobic zones; then, they were released by the bacteria in the SAD reactor. In addition, the tryptophan-like materials had a very significant positive linear correlation with the concentrations of soluble chemical oxygen demand.

A novel system integrating Johannesburg (JHB) and sulfur autotrophic denitrification (SAD) process was proposed with the purpose of efficient removal of organic matter and nitrogen when treating low COD/TN ratio municipal wastewater. The characteristics and fate of dissolved organic matter in the Johannesburg-Sulfur autotrophic denitrification (JHB-SAD) system were investigated using excitation–emission matrix fluorescence spectroscopy with a parallel factor analysis. Three components were identified including tryptophan-like (component C1), tyrosine-like (component C2), and fulvic-like (component C3) materials. The tyrosine-like and tryptophan-like materials, which were more abundant than fulvic-like materials, were the dominant components of the raw municipal wastewater in Shenyang North Wastewater Treatment Plant. In the JHB-SAD system, the tyrosine-like and tryptophan-like materials were more efficiently removed than the fulvic-like materials, and the removal efficiencies of the three components were 80.8% (tryptophan-like materials), 72.5% (tyrosine-like materials), and 33.4% (fulvic-like materials), respectively. Furthermore, the removal performance of the three components varied in the different zones of the JHB-SAD system. The tryptophan-like and fulvic-like materials were removed in the pre-anoxic, anaerobic, and aerobic zones. The tyrosine-like materials were mainly degraded in the anoxic and aerobic zones; then, they were released by the bacteria in the SAD reactor. In addition, the tryptophan-like materials had a very significant positive linear correlation with the concentrations of soluble chemical oxygen demand.

AbstractIn order to investigate the effect of operational mode, temperature, and planting on the performance of tidal flow constructed wetland (TFCW), four lab-scale units were operated in parallel experiments. They were operated in three cycles d−1tidal flow mode with planting (3TF+P), three cycles d−1tidal flow mode without planting (3TF), one cycle d−1tidal flow mode with planting (1TF+P), and continuous flow mode with planting (CF+P), respectively. The results demonstrated that the multi-cycle tidal flow operational mode promoted the biofilm growth and pollutant removal with the low relative clogging coefficient (RCC) of 21.42% during the whole experimental period. The average COD, -N, and -P area removal rate in 3TF+P reached 18.00, 2.38, and 0.24 g m−2 d−1, respectively. Meanwhile, the influence of low temperature on the performance of TFCW in the winter was partially compensated by the multi-cycle operational mode, which made the performance of TFCW more stable than that of other systems under temperature variation. Planting Canna indicaL.(Cannaceae) led to an increase in average area removal rate of N with 24.17%. The net uptake of N by planting was 0.35 g m−2 d−1, which accounted for 17.95% of the total nitrogen removal. Besides the direct uptake, the combination of aerobic zone close to rhizosphere and anaerobic zone around rhizosphere may also play an important role in the nitrification–denitrification process. The direct P removal by Canna indicaL. (Cannaceae) was quantified as 0.01 g m−2 d−1, which only accounted for 4.17% of the -P removal.

In order to investigate the effect of operational mode, temperature, and planting on the performance of tidal flow constructed wetland (TFCW), four lab-scale units were operated in parallel experiments. They were operated in three cycles d−1tidal flow mode with planting (3TF+P), three cycles d−1tidal flow mode without planting (3TF), one cycle d−1tidal flow mode with planting (1TF+P), and continuous flow mode with planting (CF+P), respectively. The results demonstrated that the multi-cycle tidal flow operational mode promoted the biofilm growth and pollutant removal with the low relative clogging coefficient (RCC) of 21.42% during the whole experimental period. The average COD, NH4+-N, and PO43--P area removal rate in 3TF+P reached 18.00, 2.38, and 0.24g m−2 d−1, respectively. Meanwhile, the influence of low temperature on the performance of TFCW in the winter was partially compensated by the multi-cycle operational mode, which made the performance of TFCW more stable than that of other systems under temperature variation. Planting Canna indicaL.(Cannaceae) led to an increase in average area removal rate of N with 24.17%. The net uptake of N by planting was 0.35g m−2 d−1, which accounted for 17.95% of the total nitrogen removal. Besides the direct uptake, the combination of aerobic zone close to rhizosphere and anaerobic zone around rhizosphere may also play an important role in the nitrification–denitrification process. The direct P removal by Canna indicaL. (Cannaceae) was quantified as 0.01g m−2 d−1, which only accounted for 4.17% of the PO43--P removal.

Multi-walled carbon nanotube modified laccase-carrying electrospun fibrous membranes (MWCNTs-LCEFMs) were fabricated viaco-electrospinning a poly(d,l-lactide) (PDLLA)/laccase/MWCNT mixed solution. A triblock copolymer PEO–PPO–PEO (F108) was added as an emulsifier to promote the dispersion of the laccase and acid-treated short MWCNTs in the electrospinning solution. The characterization results illustrated that the electrospun nanofibers possess a feature of being bead-free, porous and having a core–shell structure, with active laccase encapsulated inside the fibers and one end of some MWCNTs inserted into the edge of the pores. After being modified by a small amount (1.5 wt%, vs.PDLLA) of MWCNTs, the specific surface area and mechanical tensile strength of MWCNTs-LCEFMs were enhanced by about 2 and 3 times compared to those of LCEFMs, respectively. The MWCNTs-LCEFMs were applied to remove the widespread phenolic organics from water, including bisphenol A (BPA), triclosan (TCS) and 2,4-dichlorophenol (2,4-DCP). Benefiting from the improved adsorption property for substrates and the promoted electron transfer in the laccase-catalytic reaction, the MWCNTs-LCEFMs showed higher activity recovery (88.9% vs.free laccase), and better storage and operational stability than LCEFMs. In addition, the adsorption efficiencies of MWCNTs-LCEFMs for BPA and 2,4-DCP were enhanced by more than 50%. The removal efficiencies of MWCNTs-LCEFMs for 2,4-DCP, BPA and TCS reached 92.6 ± 0.74%, 95.5 ± 0.46% and 99.7 ± 0.02%, respectively, with the degradation efficiencies reaching 81.7 ± 1.9%, 90.5 ± 1.1% and 85.6 ± 1.5%, respectively. Meanwhile, the removal half-life (t1/2) of 2,4-DCP, BPA and TCS by the MWCNTs-LCEFMs was shortened to 7.9 ± 0.07, 4.7 ± 0.04 and 0.76 ± 0.01 min, respectively. The removal mechanism of these phenolic pollutants by MWCNTs-LCEFMs was considered as a synergistic effect of membrane adsorption and laccase degradation, where the catalytic degradation of laccase was obviously strengthened by the improved adsorption (pre-concentration) process of the fibers and MWCNTs, and the enhanced electron transfer process of MWCNTs.

AbstractIn this study, the homogenous Fenton process was employed for the pretreatment of dry-spun acrylic fiber (DAF) manufacturing wastewater. Central composite design and response surface methodology (RSM) were used for the design and optimization of the Fenton process. A second-order polynomial regression equation was developed to describe the chemical oxygen demand (COD) removal efficiency of Fenton process and validated by the analysis of variance and residual techniques. The interaction effects of the operational parameters were investigated using response surface analysis. The optimum parameters were determined as 90.00 mM H2O2, 30.00 mM Fe2+, pH of 3.14, and reaction time of 114 min. Under the optimum reaction conditions, the COD removal efficiency was 47.1%, which was highly consistent with the value predicted by the model equation, with a deviation of 2.89%. Furthermore, the biodegradability and toxicity of raw and treated wastewater were compared; the results showed that the (BOD5)/COD (B/C) ratio increased from 0.35 to 0.67, whereas the light loss of Vibrio fisheribacteria decreased from 92 to 31%. The Fenton process was an effective method for pretreating DAF wastewater, and RSM was suitable for process design and optimization.

In this study, the homogenous Fenton process was employed for the pretreatment of dry-spun acrylic fiber (DAF) manufacturing wastewater. Central composite design and response surface methodology (RSM) were used for the design and optimization of the Fenton process. A second-order polynomial regression equation was developed to describe the chemical oxygen demand (COD) removal efficiency of Fenton process and validated by the analysis of variance and residual techniques. The interaction effects of the operational parameters were investigated using response surface analysis. The optimum parameters were determined as 90.00 mM H2O2, 30.00 mM Fe2+, pH of 3.14, and reaction time of 114 min. Under the optimum reaction conditions, the COD removal efficiency was 47.1%, which was highly consistent with the value predicted by the model equation, with a deviation of 2.89%. Furthermore, the biodegradability and toxicity of raw and treated wastewater were compared; the results showed that the (BOD5)/COD (B/C) ratio increased from 0.35 to 0.67, whereas the light loss of Vibrio fisheribacteria decreased from 92 to 31%. The Fenton process was an effective method for pretreating DAF wastewater, and RSM was suitable for process design and optimization.

AbstractAn integrated process of membrane bioreactor (MBR)—advanced ozonation (AO)—biological aerated filters (BAFs) was developed for the treatment of dry-spun acrylic fiber manufacturing wastewater in pilot scale. The results show that the removal efficiencies of chemical oxygen demand (COD) and ammonia nitrogen (-N) could exceed 90.0 and 95.0%, respectively. The COD concentration in the total effluent was maintained at 80.0–100 mg/L, and the -N concentration was below 10.0 mg/L. Both the MBR and BAFs could adapt to the influent of practical wastewater after a period of sludge acclimatization. The removal efficiencies of COD and -N in the MBR were maintained at 65.8–71.9 and 59.4–67.5%, respectively. Excitation–emission matrix spectroscopy confirmed that most of the easy degradable organics were removed in the MBR process. After the AO treatment, COD concentration in the wastewater was reduced by 106–157 mg/L and the biodegradability was enhanced. Simultaneous nitrification–denitrification was performed in the biofilm of BAFs, and the removal efficiency of total nitrogen was in the range of 58.2–71.6% after the entire integrated process.

An integrated process of membrane bioreactor (MBR)—advanced ozonation (AO)—biological aerated filters (BAFs) was developed for the treatment of dry-spun acrylic fiber manufacturing wastewater in pilot scale. The results show that the removal efficiencies of chemical oxygen demand (COD) and ammonia nitrogen (NH4+-N) could exceed 90.0 and 95.0%, respectively. The COD concentration in the total effluent was maintained at 80.0–100 mg/L, and the NH4+-N concentration was below 10.0 mg/L. Both the MBR and BAFs could adapt to the influent of practical wastewater after a period of sludge acclimatization. The removal efficiencies of COD and NH4+-N in the MBR were maintained at 65.8–71.9 and 59.4–67.5%, respectively. Excitation–emission matrix spectroscopy confirmed that most of the easy degradable organics were removed in the MBR process. After the AO treatment, COD concentration in the wastewater was reduced by 106–157 mg/L and the biodegradability was enhanced. Simultaneous nitrification–denitrification was performed in the biofilm of BAFs, and the removal efficiency of total nitrogen was in the range of 58.2–71.6% after the entire integrated process.

In this work, stable concentrated aqueous dispersions of size-controlled silver nanoparticles were prepared by microwave irradiation of silver nitrate (AgNO 3 )/polyvinyl pyrrolidone (PVP) solution using polyvinyl pyrrolidone (PVP) as a reducing and stabilising agent. Crystal structure, size, optical properties of the silver nanoparticles were characterised by means of X-ray diffraction (XRD), scanning electron microscope (SEM), ultraviolet visible spectroscopy (UV-vis), Fourier transform infrared (FT-IR). Quasi-spherical nanoparticles, nanocube and flake-like nanoparticles were synthesised by controlling the experimental parameters such as the ratio of PVP to AgNO 3 , and the particle size can be conveniently adjusted to 50 nm.

For the trace determination and automated continuous monitoring of volatile organic compounds (VOCs) in surface water, a large volume-direct aqueous injection-gas chromatography (LV-DAI-GC) method was optimized for the following parameters: packed sorbent, inlet temperature, injection volume, detector configurations and sample renewal. Using the packed sorbent lab-made with lithium chloride and diatomite 101 W, at an inlet temperature of 140 °C, 14 typical VOCs were separated from a 50 μL water matrix in 0.3 min. Coupled with a flame ionization detector (FID), an electron capture detector (ECD) and a flame photometric detector (FPD), the method quantification limits (MQLs) for the 14 typical VOCs were 0.008–7 μg L−1. For the samples from the simulated VOC pollution incidents, the relative standard deviations (RSDs) and relative errors (REs) were 5.9% and 9.5%, respectively. For real samples from a river polluted with VOCs, the quantitative results using LV-DAI-GC agreed well with those of purge-and-trap GC (PT-GC). The optimized reliable LV-DAI-GC could be applied to the automated continuous monitoring of VOCs in surface water and an early warning of VOC pollution incidents.

Urban regeneration is of considerable contemporary public interest and debate. Sustainable urban regeneration requires a comprehensive and integrated vision and action to address the resolution of urban problems and bring about a lasting improvement in the economic, physical, social, and environmental conditions of an area that has been subject to change. Thus, there are increased requirements for decision making and knowledge sharing by urban planners, local authorities, and other practitioners to achieve sustainability in urban regeneration activities. To address these challenges the research team of the Sustainable Urban Regeneration (SURegen) project (UK Government EPSRC funded, £2.5 Million, in the SUE programme) designed and implemented a prototype Regeneration Workbench, which addresses the key challenges in regeneration practice and provides a flexible and integrated e-platform. Over the past 20 years many Planning Support Systems (PSS) have been developed. Whereas most of these systems address a small range of issues, the SURegen workbench takes a holistic approach to all aspects that have influence sustainable regeneration. Furthermore, the workbench specifically addresses the management of urban regeneration projects and the skills gaps amongst regeneration professionals. This article describes the urban challenges addressed and details the SURegen approach to meeting these challenges.

A multistage permanent deformation (PD) test of geomaterials is more economical than the single-stage variety. Only one sample must be tested for the former, whereas several tests on multiple samples are required for the latter. Yet no standards exist for this test in the United States, nor is there a generally accepted procedure for determining the deviator stress to separate acceptable from unacceptable behavior in a multistage PD test. On the basis of both single- and multistage PD tests on a virgin aggregate and two recycled materials and their blends, this paper proposes a procedure to identify the material shakedown limit in a multi-stage PD test. Resilient modulus increases under low deviator stresses and decreases when deviator stresses are high or near failure. When applied to the materials tested, the multistage PD test predicted correctly the behavior of single-stage test samples 78% of the time. To validate the procedure, additional verification and a standard test load sequence are needed. The sequence proposed in NCHRP Report 598 presents a good starting point. The deviator stress intervals should be small enough to allow all three behavioral ranges to be captured and the load frequency low enough for the sample to drain and recover from viscous effects. One more recommendation is to use a confining stress representative of the field pavement section to be studied.

A multistage permanent deformation (PD) test of geomaterials is more economical than the single-stage variety. Only one sample must be tested for the former, whereas several tests on multiple samples are required for the latter. Yet no standards exist for this test in the United States, nor is there a generally accepted procedure for determining the deviator stress to separate acceptable from unacceptable behavior in a multistage PD test. On the basis of both single- and multistage PD tests on a virgin aggregate and two recycled materials and their blends, this paper proposes a procedure to identify the material shakedown limit in a multistage PD test. Resilient modulus increases under low deviator stresses and decreases when deviator stresses are high or near failure. When applied to the materials tested, the multistage PD test predicted correctly the behavior of single-stage test samples 78% of the time. To validate the procedure, additional verification and a standard test load sequence are needed. The sequence proposed in NCHRP Report 598 presents a good starting point. The deviator stress intervals should be small enough to allow all three behavioral ranges to be captured and the load frequency low enough for the sample to drain and recover from viscous effects. One more recommendation is to use a confining stress representative of the field pavement section to be studied.

In this study, the synergistic extraction system of trioctylmethyl ammonium chloride (N263)-tributyl phosphate (TBP)-n-octanol-sulfonated kerosene was used to enrich and recover valuable metals from cyanide gold extraction of wastewater. The effects of the proportion of N263 and TBP, contact time, initial pH of water phase, temperature, and phase ratio (O/A) on the extraction percentage of metal cyanide complex ions and the synergistic extraction reaction mechanism were mainly investigated. Results showed that the single-stage extraction percentages of Cu, Zn, and Fe ions in wastewater were 99.87%, 99.8%, and 96.2%, respectively, and the saturated extraction capacity was 4356.4 mg/L under the conditions of N263 (20 vol%)-TBP (20 vol%)-n-octanol (10 vol%)-sulfonated kerosene system at 25 °C, O/A of 1:1, pH of 10, and contact time of 5 min. Fourier transform infrared spectroscopy (FT-IR) and electrospray ionization mass spectrometry (ESI-MS) analyses showed that metals entered the organic phase in the form of metal cyanide complex ions during extraction. Metal cyanide complex ions preferentially combined with TBP to lose hydrophilicity and then reacted with N263 cations to enter the organic phase. The saturated organic phase was stripped by NaOH and NaSCN mixed solution, and the total concentration of metal ions in the stripping solution reached 11,996.6 mg/L.

A comparison of the California bearing ratio (CBR) for recycled glass (RG) with other recycled materials and a basaltic virgin aggregate, all having similar gradations, revealed that the CBR of RG is superior to that of recycled asphalt pavement but less than that of recycled concrete and virgin aggregate. Direct shear tests were then run on the as-received gradation to derive strength parameters for RG prepared at very high and very low relative densities. For "dense" RG, the peak failure envelope was nonlinear with secant friction angles varying from 50° to 61°. For "loose" RG, the peak and critical state failure envelopes were linear with friction angles of 41° and 38°, respectively. Bolton's postulate that the peak friction angle is approximately equal to the critical friction angle plus 0.8 times the maximum angle of dilation works well for the RG tested in direct shear. A friction angle of 38° at critical state is significant, implying that RG has the potential to be used in even more foundation and ground improvement applications that are so often associated with transportation infrastructure construction. With increased use of recycled materials, civil engineers can help comply with the demand for sustainable development, a major theme in society today.

A comparison of the California bearing ratio (CBR) for recycled glass (RG) with other recycled materials and a basaltic virgin aggregate, all having similar gradations, revealed that the CBR of RG is superior to that of recycled asphalt pavement but less than that of recycled concrete and virgin aggregate. Direct shear tests were then run on the as-received gradation to derive strength parameters for RG prepared at very high and very low relative densities. For “dense” RG, the peak failure envelope was nonlinear with secant friction angles varying from 50° to 61°. For “loose” RG, the peak and critical state failure envelopes were linear with friction angles of 41° and 38°, respectively. Bolton's postulate that the peak friction angle is approximately equal to the critical friction angle plus 0.8 times the maximum angle of dilation works well for the RG tested in direct shear. A friction angle of 38° at critical state is significant, implying that RG has the potential to be used in even more foundation and ground improvement applications that are so often associated with transportation infrastructure construction. With increased use of recycled materials, civil engineers can help comply with the demand for sustainable development, a major theme in society today.

Carbonaceous gold ores are difficult to treat because of the “preg-robbing” by carbonaceous matters and locking by minerals. Roasting is the most commonly used method that is useful in dealing with carbonaceous gold ores. In this study, flotation gold concentrates containing sulfides and carbonaceous matters were investigated to ascertain the reaction process and the matters’ transformation characteristics in different temperatures by vacuum roasting pretreatment. Calcine and volatile condensates were characterized with several techniques. In the process of vacuum roasting, the main chemical reactions were decomposition reaction and carbothermic reduction reactions of sulfide ores, carbothermic reduction reactions of SiO2, and thermal decomposition reactions of organic carbon. The bad effects of “preg-robbing” by carbonaceous matters were greatly weakened by the thermal decomposition and carbothermal reduction. The gold locking minerals were mainly removed by reduction reactions. The sulfides were removed in ways that did not produce SO2. The removal of sulfur and carbonaceous matters during the vacuum roasting process was 95.83% and 65.38%, respectively. Direct cyanidation of the calcine extracted from 2.13% to 88.37% of the gold content with a vacuum degree of 10 Pa and roasting from 25°C to 1,200°C for 30 min.