Coal fly ash (CFA), is a by-product of coal combustion which has been regarded as a recalcitrant solid waste. In this work, an effective and low-cost high alumina coal fly ash catalyst was synthesised by using of high alumina coal fly ash and Fe(II)/Fe(III) oxide and the catalytic capacity of o-methyl phenol (OMP) in the Oxidative degradation was investigated. XRD, SEM and XPS were used to characterize the catalyst and the results indicated that the Fe(II)/Fe(III) oxide was successfully introduced. The character results showed that the surface area of CFA increased with increasing the loading content of the Fe(II)/Fe(III) oxide and the biggest surface area is about 69.3 m(2)/g with the loading content of 15 wt.%. The degradation experiment results showed that the catalytic ozonation capacity was affected by the loading of Fe(II)/Fe(III) oxide and the solution pH. The biggest removal efficiency of OMP and the reveal rate of COD were 100.0% and 44.5% which appeared at pH of 11 with the loading content of Fe(II)/Fe(III) oxide of 15 wt.%. The kinetic study of the catalytic ozonation degradation process revealed that the degradation process follows the first order kinetic model. It is indicats that the degradation process of OMP was derived from the heterogeneous Fenton process and affected by the solution pH. (C) 2016 Elsevier Ltd. All rights reserved.

In this study, we explored an effective and low-cost catalyst and its adsorption capacity and catalytic capacity for Methyl Orange Fenton oxidation degradation were investigated. The catalyst was directly prepared by reuse of magnetic iron oxide (Fe3O4) after saturated adsorption of vanadium (V) from waste SCR (Selective Catalytic Reduction) catalyst. The obtained catalyst was characterized by FTIR, XPS and the results showed that vanadium (V) adsorption process of Fe3O4 nanoparticles was non-redox reaction. The effects of pH, adsorption kinetics and equilibrium isotherms of adsorption were assessed. Adsorption of vanadium (V) ions by Fe3O4 nanoparticles could be well described by the Sips isotherm model which controlled by the mixed surface reaction and diffusion (MSRDC) adsorption kinetic model. The results show that vanadium (V) was mainly adsorbed on external surface of the Fe3O4 nanoparticles. The separation-recovering tungsten (VI) and vanadium (V) from waste SCR catalyst alkaline solution through pH adjustment was also investigated in this study. The results obtained from the experiments indicated that tungsten (VI) was selectively adsorbed from vanadium (V)/tungsten (VI) mixed solution in certain acidic condition by Fe3O4 nanoparticle to realize their recovery. Tungsten (V) with some impurity can be obtained by releasing from adsorbent, which can be confirmed by ICP-AES. The Methyl Orange degradation catalytic performance illustrated that the catalyst could improve Fenton reaction effectively at pH = 3.0 compare to Fe3O4 nanoparticles alone. Therefore, Fe3O4 nanoparticle adsorbed vanadium (V) has a potential to be employed as a heterogeneous Fenton-like catalyst in the present contribution, and its catalytic activity was mainly evaluated in terms of the decoloration efficiency of Methyl Orange.

This paper studies on the preparation and application of a papermaking sludge bioflocculant (named PSBF). Compared to ultrasonic, thermal and alkaline-ultrasonic treatment, the optimal alkaline hydrolysis for bioflocculant preparation was confirmed with an alkali dosage of 2.25 g/g TS. This bioflocculant was used for practical papermaking wastewater treatment with an achievement of removing 75% of COD and 90% of colority at optimal dosage of 1 ml/L together with CaCl2 (1%, w/w) of 110 ml/L at pH 11. Pilot reactors were designed and installed with COD removal rate of 68% and colority reduction of 85%.

A novel combination of magnetic adsorptive and coagulative strategy which was applied to remove molybdenum (Mo) ions from surface water was investigated in this study. The ferromagnetic nanoclusters and ferromagnetic nanoclusters-ferric flocs composite coagulant were characterized in terms of typical properties, structure and morphological analysis (TEM, XRD, M-H hysteresis curves, particle size distribution). Different removal agents of Mo was investigated that the removal rate of Mo was ferromagnetic nanoclusters-FeCl3 > FeCl3 >AlCl3 >TiCl4. Jar tests were employed to evaluate the removal performances. The coagulation performances of ferromagnetic nanoclusters-ferric flocs were compared under different pH conditions and dosages. Various factors influencing the removal of Mo(VI), e.g. pH, the dose of ferromagnetic nanoparticle, FeCl3, were conducted using a 3(3) full factorial design approach. The results show that the newly addition of ferromagnetic nanoparticles obviously had a trend to form cluster, especially magnetic force acted as a key role that may promote the formation of ferromagnetic nanoclusters. The better removal performance of Mo could be attributed to the co-effect of ferromagnetic nanoclusters and ferric flocs. Meanwhile, in order to satisfy the national drinking water criterion, the reinforce effect of ferromagnetic nanoclusters on reducing the concentration of ferric (Fe) ions in effluent makes sure that the content of ferric ions under 0.3 mg/L. The experimental results indicated that mechanism of the molybdate removal was a physical surface adsorption which might combine with chemical action. (C) 2015 Elsevier B.V. All rights reserved.

A novel process, natural freezing, was developed to remove ammonia from wastewater in this study.A series of experiments were carried out to examine the ammonia removal and ice productivity in laboratory in Dalian, the effect of operating conditions such as solution concentration, pH, ice content formed, and Na + concentration were conducted.The results showed that the natural freezing method could effectively remove ammonia from wastewater; about 80 % ammonia was removed at about 500 mg/L initial ammonia concentration, while the fraction of ice formed was about 50% controlling the pH at 7. When the freezing process was carried out under natural temperature conditions, the obvious advantage was the savings in energy.Unlike mechanical freezing process, natural freezing usually did not require complex facilities and thus is simple and less expensive to operate.Therefore, the natural freezing method was characterized by low pollution, simple facility, low energy consumption, and it is feasible in most of regions north of China because of the long winter and low temperature conditions.This study could introduce the fundamental principle and research development of the natural freezing method.

Chitosan (CS) was modified by using sodium chloride as the porogen agent to remove nickel ions in seawater. The modified CS was characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and pH(pzc) analysis. The influence of pH, background electrolyte concentrations on nickel ions adsorption by CS and modified CS was investigated. The results showed that nickel ions adsorption capacity by CS and modified CS are greatly improve when background electrolyte concentration increase from 0 to 0.8556 mol/L, indicating the modified CS could be an excellent adsorbent to remove nickel ions from seawater. Langmuir, Freundlich, Redlich-Peterson, and Langmuir-Freundlich models were used to illustrate the isotherms of the adsorption process. The mechanism of the adsorption was a combination of electrostatic interaction and chemical adsorption. The nickel species distribution was predicted by Visual MINTEQ program, and the total content of Ni2+, NiOH+, and NiCl+ cation species increased with the increase of ion strength in aqueous, which could demonstrate the adsorption mechanism is dominantly an electrostatic interaction as well. The modified CS could be a potential material to remove nickel ions in pretreatment of seawater for mariculture or industrial applications.

Since commercial chitosan powder may dissolve in water to some degree and demands to be modified chemically to create its own exclusive pore canal we have synthetized two different modified chitosan beads in this investigation by using glutaraldehyde as crosslinking agent, significantly, novel porogen silica sol and methanol, and analysis means SEM, FTIR and BET demonstrated that the surface area and pore size improved signally. Moreover, the adsorption conditions pH and ionic strength have been considered, and the maximum adsorption capacity of nickel ions was 32.40 mg/g at the optimum condition. Furthermore, the main model equations on isotherm and kinetics have been deliberated and the results clearly revealed. that Freundlich, external mass transfer, intra particle diffusion and pseudo second order model fitted better to the experimental data (R2 > 0.99, all). It is expected that this results would be serviceable to remove metals from wastewater using chitosan and its derivatives.

Electrophoretic deposition (EPD) method was used to fabricate Carbon nanotubes (CNTs) and Ca-Selective zeolite composite electrode. The prepared electrode was employed in electrosorption of calcium ions in capacitive deionization. The morphology, porous size distribution, pore volume and electrochemical properties were characterized by scanning electron microscopy, N2 adsorption at 77K and Cyclic Voltammetry (CV), respectively. The results obtained from experiments showed that the optimum proportion between CNTs and zeolite was 1:4. It was also found that the optimum applied electrosorption voltage was 2.0V and the maximum equilibrium electrosorption capacity was 25mg/g with initial Ca2+ concentration of 750mg/L. The electrosorption process could be validated by both of pseudo first and second order kinetic models. Furthermore, the selective ion electrosorption experiments were repeated in solution with different ions, and it was observed that the electrosorption capacities of cations on the CNTs composite electrode followed the order of Ca2+>Mg2+>Na+. Finally, the prepared electrode can be reused in long-term electrosorption process.

Hydrogen gas production coupled with phenol electrochemical oxidation was investigated in a novel two-region equipment. The phenol degradation, COD removal, hydrogen production, kinetic, Instantaneous Current Efficiency for COD removal (ICECOD), and hydrogen gas yield (YH2) of simulated phenol solution electrochemical oxidation degradation at 3V applied voltage were surveyed. The results indicated that three stages were observed during the electrochemical oxidation of simulated phenol in this study. The kinetic study showed that first order model well described each stage of phenol electrochemical oxidation process. The ICECOD increased slightly at the initial stage, and dramatically at the second stage, while fell at the finally stage, indicating water molecules were finally participated in the formation of hydrogen due to the degradation of phenol and COD. Hydrogen products from redox reaction of H+ which release from the degradation of organics oxidation reaction at the anode. Furthermore, the mechanism was discussed and showed that phenol transformed into benzoquinone intermediate in the first step, then the ring was broken and further oxidized into organic compounds like muconic acid, maleic acid or oxalic acid as intermediates in the followed stage, and finally disintegrated into CO2 and H2O in electrochemical oxidation process, which demonstrated by the UV and LC–MS images analysis. It could be seen that hydrogen gas production coupled with organic wastewaters electrochemical oxidation would be an effective approach for energy recovery and wastewater reutilization.

Hydrogen production coupled with the electrochemical treatment of organic wastewater at the anode was investigated.Phenol,glucose,starch were used to investigate the degradation of organic matter,hydrogen production,and their relationship.The results indicated that degradation of organic matter was different due to the structure and properties of organic matter and hydrogen production changed as well.Meanwhile,degradation of phenol was effective,and hydrogen production volume and rate were higher than glucose and starch.Kinetic study of phenol showed a first order model,and the reaction constants at 5 V and 10 V were 0.01498 h 1and 0.1202 h 1respectively,which increased with the increase of voltage.These results could provide theoretical foundations for rational treatments of different organic wastewaters.

Constructed wetland was recognized as an economic and ecological-friendly technique to reduce excess nitrogen (N) and phosphorus (P) in secondary effluent from sewage treatment plants. In this study, the removal capacity of non-planted control treatment, one stage constructed wetland with different feeding strategies, and multi-stage constructed wetland on chemical oxygen demand (COD), total nitrogen (TN), ammonia nitrogen (NH4+-N) and total phosphorus (TP)were evaluated. The results showed that all the planted treatments displayed superior removal efficiency for COD and nutrients in compare with the non-planted control treatment. The feeding strategy could influence COD andN removal rate that the averageremoval rate of the COD, TN, and NH4+-N in intermittent feeding treatment (61.3%, 52.6% and 88.7%) was much higher than continuous feeding treatment (46.8%, 20.6% and 73.9%). Higher TN and TP removal rate was observed in multi-stage constructed wetland (74.1% and 98.1%) than the single-stage constructed wetland (20.6% and 96.9%). This implied that intermittent feeding strategy and the multi-stage constructed wetland may have a good potential for removing nutrients from secondary effluent.

The present study explores the potential of Mg-Ca-Al (NO3) hydrotalcite-like compounds (MgCaAlNO3-HTlcs) for the removal of fluoride from protein solutions. In this study, the Mg3-xCaxAlNO3-HTlcs (x = 0-3, x is the mol.% of Ca) were synthesized and characterized by SEM, XRD, FTIR, BET, ICP-AES and pHzpc analysis. The sorption experiments were conducted in protein systems of bovine serum albumin (BSA) and lysozyme (LSZ). The batch experiment results showed that the NO3-HTlc with Mg/Ca/Al molar ratio of 2.5/0.5/1 had remarkable fluoride sorption ability with maximum sorption capacities of 82.35 mg/g and 72.69 mg/g at pH 5.0 and 40 degrees C in BSA and LSZ system, respectively. Moreover, the loss of BSA of 0.71% was low and there was no loss of LSZ. It was evident that the Mg2.5Ca0.5AlNO3-HTlc could selectively adsorb fluoride from protein solutions. The equilibrium sorption data fitted well to the Langmuir model and the kinetic data conformed to the pseudo-second-order model. Thermodynamic parameters (Delta G degrees, Delta H degrees and Delta S degrees) were evaluated and revealed that the sorption process was spontaneous and endothermic in nature. Furthermore, the results from Antarctic krill processing wastewater study confirmed the feasibility and practicality of the Mg2.5Ca0.5AlNO3-HTlc for fluoride removal in fluoride bearing protein system. (C) 2012 Elsevier B.V. All rights reserved.

The influences to regular pattern of alkylation and the product distribution from the reaction temperature,molar ratio of toluene/propylene and weight hourly space velocity were investigated by isothermal fixed bed reactor,and substances comprised in the product detected with mass spectrometer.The results showed that the catalyst,made from β zeolites,had excellent catalytic activity and selectivity in alkylation reaction of toluene with liquid propylene.The optimum reaction conditions were that the temperature was 220 ℃,molar ratio of toluene/propylene,7.75,and mass space velocity,3.4 h-1.

Abstract The disposal concentration from seawater desalination plant has a significant impact on environment, which needs to pay strict attention due to the rapid development of desalination plant. The chemical elements extracted from seawater are very scarce on land such as potassium or very expensive such as lithium. The abstraction selectivity of them as the salt co-products using the synthesis solid inorganic material was tested in the lab. The results show that the technology is feasible to recover lithium as LiCl by ion sieve material (denoted IS-Li) which has good selectivity for lithium ions from the concentrated brine and the adsorption capacity is 25 mg g−1. And there are insignificant effect from the competed ions, although the order of effect on the capacity is K > Ca > Mg > Na. The material (denoted A-K) which obtained from zeolite has good adsorption capacity of potassium of about 20 mg g−1 in the condition of mixed concentrated brine, but the maximum adsorption amount decreased due to the e...

Magnetic Fe3O4/chitosan nanoparticles were synthesized for lysozyme separation from solution. The adsorption of lysozyme was investigated on magnetic Fe3O4/chitosan nanoparticles at fixed pH 6.0, because the enzymatic activity of lysozyme reaches its maximum in this condition. The influence of initial lysozyme concentration, temperature and contact time on lysozyme adsorption was studied. The results of lysozyme adsorption indicated that the adsorption isotherm fitted Sips model well. The maximum adsorption capacity was 144.11mg/g at 310 K. The thermodynamic parameters, ΔG0, ΔH0 and ΔS0, illustrated that the adsorption of lysozyme was endothermic and spontaneous process.

The removal of nickel ions in wastewater by enhanced ultrafiltration and adsorption was studied. Nickel ions was firstly complexed with PAA (Polymer acrylic acid) to increase the molecular weight which was larger than the molecular weight cut-off (WMCO) of the ultrafiltration membrane. Then the nickel ions contained in the concentrated solution was removed by peat. The effects of pH, dosage of PAA, background electrolyte and copper ions were studied as well. The results showed that the pH, dosage of PAA and existence of copper ions affected the removal of nickel ions, while the background electrolyte had no effects. And the treated peat is an effective adsorbent for the removal of nickel ions in the concentrated solution.

In this paper, a cost-effective material, Ca-Selective zeolite was synthesized and investigated to be used in the sorption of calcium. The adsorptive experiments were carried out in batch systems. Effects of contact time, initial concentration and ionic strength on the sorption of calcium were tested. Three different kinetic models including pseudo-first-order model, pseudo-second-order model and intra-particle diffusion model were used to evaluate the adsorption kinetics. The results obtained from the study illustrated that chemical exchange and intra-particle diffusion may be the rate-determining steps of the exchange process.

Lab experiment was conducted in order to optimize the condition of decolorizing Reactive X-3B Red dyestuff by using GTY, a strain of salt-tolerant bacterium. The findings have proved the capability of salt-tolerant GTY for decolorization of Reactive X-3B Red in a wide range of pH and dye concentrations. The best efficiency was achieved with pH 7～9 and initial dye concentrations less than 600mg/L. GTY growing in the logarithmic stage showed better per-forrnance with 90% of the decolorization rate in 24h. Higher inoculation concentration could speed up the decolorization, but had no evident improvement on final declorization efficiency. It is concluded that the best inoculation concentration was at 5% after balancing both the cost and declorization result.

A composite coagulant was prepared by magnetic nanoparticles and polyferric chloride (PFC) for Microcystis aeruginosa removal. The magnetic nanoparticles and composite coagulant were characterized in terms of typical properties, structure and morphological analysis (TEM, XRD and FTIR). The coagulation performances of magnetic nanoparticles/PFC (MPFC) and PFC were compared under different pH conditions and coagulant dosages. Natural water spiked with M. aeruginosa cells was also investigated to study the effect of natural organic matter (NOM) on the function of magnetic nanoparticles. The results show that the composite coagulant exhibits improved coagulation efficiency with higher removal values and slighter pH dependence. The better performance could be attributed to the co-effect of PFC and magnetic nanoparticles. The newly added magnetite acts as an adsorber, which favors the M. aeruginosa removal by facilitating the formation of settleable flocs and reducing the negative influence of NOM at optimal dosages. In addition, settling kinetic studies present accelerated settling velocity of MPFC under external magnetic field, emphasising the role plays by magnetic nanoparticles in promoting the coagulation efficiency.

With the rapid development of industry and agriculture, there are thousands of tons phosphate and nitrogen releasing into surface water. Phosphate becomes the main reason for eutrophication, resulting in deterioration of water quality. Ferric sludge from drinking waterworks was found to possess potential efficiency to remove phosphate ions from aqueous solutions. The maximum phosphate ions adsorption capacity was about 15.5 mg/g at pH around 5 and contact time above 4 hours in the batch system by newly dewatered sludge. Column experiments showed that higher concentration of the solution was in favor of fast equilibration. Adsorption characteristic studies have been carried out by Langmuir, Freundlich, Temkin and Dubinin-Radushkevick (D-R) isotherms. The results showed that the experimental data fitted better to Freundlich and Dubinin-Radushkevick (D-R) isotherms. Above studies suggested that the mechanism of phosphate ions removal followed inner-sphere complexes.