Effect of Ferric Chloride on the Properties of Biological Sludge in Co-precipitation Phosphorus Removal Process

This paper studied the effect of ferric chloride on waste sludge digestion,dewatering and sedimentation under the optimized doses in co-precipitation phosphorus removal process.The experimental results showed that the concentration of mixed liquid suspended solid(MLSS) was 2436 mg.L-1 and 2385 mg.L-1 in co-precipitation phosphorus removal process(CPR) and biological phosphorous removal process(BPR),respectively.The sludge reduction ratio for each process was 22.6% and 24.6% in aerobic digestion,and 27.6% and 29.9% in anaerobic digestion,respectively.Due to the addition of chemical to the end of aeration tank,the sludge content of CPR was slightly higher than that of BPR,but the sludge reduction rate for both processes had no distinct difference.The sludge volume index(SVI) and sludge specific resistance of BPR were 126 ml.g-1 and 11.7×1012 m.kg-1,respectively,while those of CPR were only 98 ml.g-1 and 7.1×1012 m.kg-1,indicating that CPR chemical could improve sludge settling and dewatering.

Synergistic coagulation of bauxite residue-based polyaluminum ferric chloride for dyeing wastewater treatment

Considering that Fe,Al elements in bauxite residue are active components for water purification,an effective polyaluminum ferric chloride(PAFC)coagulant derived from bauxite residue,with Fe2O3 content>5.1%,Al2O3%>6.5%,basicity>65%,was successfully prepared.The effect of as-prepared PAFC on the zeta potential for printing and dyeing wastewater was investigated.Comparing with polyferric chloride(PFC)and polyferric sulfate(PFS)for printing and dyeing wastewater treatment,prepared bauxite residue-based PAFC exhibited the optimal performance in the aspects of chromaticity and chemical oxygen demand(COD)removal rate.Furthermore,the combination of bauxite residue-based PAFC and PFS for synergy coagulation of such wastewater demonstrated an obvious positive effect.With the proportion between as-prepared PAFC and PFS to be 2.5:1,the COD of treated wastewater could be further reduced to meet the national level A standard of China,providing a promising route to solve the problem of substandard printing and dyeing sewage outfall by a simple coagulation strategy.

THE KINETICS OF FERRIC CHLORIDE LEACHING OF SPHALERITE IN THE MICROWAVE FIELD

The kinetics of ferric chloride leaching of sphalerite in the microwave field has being studied in this paper.According to the experimental data,the rate of dissolution of sphalerite microwave irradiation heating is faster than that with conventional heating.The dissolution of sphalerite in the microwave field was investigated in different condition of temperature,concentration of FeCl,and particle size and a nonisothermal kinetic equation has being obtained.

Pial iontophoresis of ferric chloride versus cortical ferric chloride injection in establishing iron-induced posttraumatic epilepsy animal models

BACKGROUND： In order to study the pathogenesis of iron-induced posttraumatic epilepsy （PTE）, foreign scholars have established several kinds of PTE animal models, among which, the iron- induced PTE animal models proposed by Willmore is the most famous. The iron-induced PTE animal models can be established by two methods： one is cortical ferric chloride injection （CFCI） and the other one is pial iontophoresis of ferric chloride （PIFC）. Because Willmore did not give out the elaboration of the behaviors and electroencephalograms （EEGs） of the iron induced PTE animal models established by these two methods, so we have known little about these animal models. OBJECTIVE： To observe the behaviors and EEGs of the iron-induced PTE animal models established by PIFC and CFCI, in order to compare the differences and the study value of these two methods. DESIGN： Qualitative controlled observation tria SETTING： Department of Neurosurgery, Urumqi General Hospital, Lanzhou Military Area Command of Chinese PLA. MATERIALS： Forty healthy adult male SD rats, weighing 200 to 250 g, were involved in this experiment. Reagents and instruments： Ferric chloride （FeCl3·6H2O, Sigma USA）, rat stereotaxic apparatus （ASI company, USA）, the wireless blue tooth electroencephlograms recording system （Nuocheng electric Co.Ltd, Shanghai）, a set of air turbine dental drill unit, dental base acrylic resin powder, microinjector （50 μL）, amperemeter （1 mA）, a pair of batteries, electric resistance （200 kΩ） , variable resistance （100 kΩ）, tubule with endo-meridians of 2 mm （used as import tube）, several silver wire segments and several acupuncture needles were employed in this study. METHODS： This study was carried out in the Experimental Animal Center of the Urumqi General Hospital, Lanzhou Military Area Command of Chinese PLA between November 2004 and April 2005. Establishing the PET animal models by CFCI method： Twenty SD rats were taken, intraperitoneally anesthetized with 50 mg/kg barbanylum and fixed on stereotaxic apparatus. A cranial burr hole with the diameter of 2 mm was drilled 3 mm behind the coronal suture and 2 mm lateral to the sagittal line on the left cranium. Another 5 cranial burr holes with diameter of 2 mm were drilled to place electrodes. The positions of holes were set that taking bregma as original point, sagittal line as Y-axis, the line through the original point and vertical to the Y-axis as X-axis. The unit of the coordinate axis was mm. The coordinate value of the electrodes were （4, 0）, （4, -6）, （-4, 0）, （-4, -6）, at last, a hole with the diameter of 2 mm was drilled on the center of the coronale. 5 μL ferric chloride solution （FeCl3, 100 mmol/L, pH 1.5） was injected into the sensorimotor cortex of rats using microinjector within 5 minutes. The needling depth was 3 mm. The needle was retained for 5 minutes so as to prevent the outflow of liquid. Establishing the PTE animal models by PIFC method： Twenty SD rats were chosen and weighed, and the procedures after weighing were as above.A cranial burr hole with the diameter of 4 mm was drilled in the position where needle inserted in animal models established by CFCI method. Cerebral dura mater was cut. Another 5 holes were drilled to place electrodes in the same position as above. The tip of tubule cotton stuffed inside （to prevent the rapid flow of FeCl3 solution, 100 mmol/L, pH 1.5） was gently connected to cerebral pia mater. The positive and negative electrodes of the amperemeter whose output current was 100 μA were connected to acupuncture needles. The acupuncture needle, which was connected to positive electrode, was inserted into ferric chloride solution, and that which was connected to negative electrode was inserted into the right forelimb of rats subcutaneously. The rats were galvanized for 10 minutes. Record of EEG： The silver wire with blunt anterior extremity was placed on the cerebral dura mater. Then, silver wire and cranial bones were firmly fixed with dental base acrylic resin power. The other side was connected to the wireless blue tooth electroencephlograms recording system to monitor EEG changes. Assessment criteria of seizure degree： Grade Ⅰ ： ＂wet dog-like＂ shudder, facial muscle convulsion and chewing;Grade Ⅱ： rhythmical nodding：Grade Ⅲ： forelimb clonus：Grade Ⅳ： forelimb clonus while standing： Grade Ⅴ： lost the balance, vert, limb＇s convulsion and the whole body＇s tic. MAIN OUTCOME MEASURES： Behaviors and EEGs changes of iron-induced PTE animal models established by PTFC and CFCI. RESULTS： All the 40 rats were involved in the result analysis. （1） The changes of the behaviors： The two animal models both had the epileptic seizures. The epileptic seizure of the animal model established by PIFC mainly presented automatic behavior of chewing, and facial muscle convulsion accompanied with chewing. Epileptic seizure reached the peak within 2.5 to 7 hours after model establishing.It was gradually decreased within 24 hours and hardly seen 1 day after model establishing. The epileptic seizure of the rat model established by CFCI mainly presented turnover upspring and limbs＇ convulsion and urinary incontinence accompanied. The epileptic seizure reached the peak within 3 to 8 hours.It was relatively frequent within 1 week and gradually decreased within 2 weeks after model establishing. The PTE animal models established by CFCI were more closed to clinical PTE process. （2） The form of seizures： The epileptic seizures of the rat model established by PIFC mainly presented grade Ⅰ , seldom presented grades Ⅲ, Ⅳ and Ⅴ; The epileptic seizures of rat model established by CFCI mainly presented the head turning to the right, body＇s rotation, then appeared as grades Ⅳ and Ⅴ, and the whole procedure lasted 1 minute. At the interval of big seizures, grade Ⅰ was observed. From the respect of seizure manifestation, the PTE models established by CFCI were more similar to human PTE. （3） EEGs changes： The sharp waves with average frequency of 9.66 Hz and average amplitude of 183.90 μV were observed on the EEGs of the model established by PIFC when the rats were suffering seizures. The spike waves with average frequency of 16.01 Hz and average amplitude of 143.60 μV were observed on the EEGs of the model established by CFCI when the rats were suffering seizures. CONCLUSTON： （1）Iron-induced PTE rat model is stable and credible. （2）Compared with PTE animal model established by PIFC, PTE animal model established by CFCI is a chronic animal model, and its seizure manifestation is more similar to human PTE. so it is worth further studies.

Metal Chlorides Supported Solid Catalysts for F-C Acylations of Arenes

A series of metal chlorides supported solid catalysts were prepared by simple wet impregnation method. Their catalytic performances for Friedel-Crafts acylation of toluene with benzoyl chloride were evaluated and the excellent results were obtained over FeC13/SiO2. These catalysts were characterized by BET, NH3-TPD and FT-IR of pyridine adsorption to clarify the structure-activity relationship. It was found that FeC13/SiO2 has larger pore size and pore volume than other catalysts, which increased the accessibility of the catalyst. In addition, FeC13/SiO2 ex- hibited higher molar ratio of Lewis acid sites and Brtpnsted acid sites, which might be another reason for the in- crease of toluene conversion. Furthermore, the reaction parameters, including temperature, time and molar ratio, were optimized. Under the optimized conditions, 91.2% conversion and 82.0% selectivity were obtained. Mean- while, the generality of the catalyst was demonstrated by the acylations of alkyl substituted aromatics. Finally, the catalyst was reused for four runs with slight loss in catalytic activity, which attributed to the drain of the active component.

Synthesis and characterization of colored layered double hydroxides for thermal stabilizer

Colored layered double hydroxides （LDHs） can be synthesized by introducing colored cations such as Fe^3＋ and Cr^3 ＋, which call be used as thermal stabilizers for polyvinyl chloride （PVC）. The yellowish Mg/Fe and bluish Mg/Cr LDHs are prepared by the co-precipitation method. The results show that the MgsCr_ CO3 and Mg3Fe_ CO3 colored layered double hydroxides can stabilize PVC for more than 30 min under the thermal aging temperature of 180 ℃. The preparation can use cheap Mg（OH） 2 instead of MgCl2, which produces a much smaller amount of the by-product NH4Cl. It is known that NH4Cl is a cheap fertilizer that is difficult to sell; therefore, the preparation is much greener and more economic than the one using magnesium salt.

Preparation and coagulation efficiency of polyaluminium ferric silicate chloride composite coagulant from wastewater of high-purity graphite production

The aim of the present work was to produce a polyaluminium ferric silicate chloride （PAFSiC） coagulant from acidic and alkaline wastewater of purifying graphite by roasting, and subsequently to evaluate coagulation efficiency of the reagent by treating surface water from the Yellow River as well as municipal wastewater in comparison with the conventional coagulant polyaluminium chloride （PAC）. The PAFSiC coagulant was prepared by co-polymerization. The effects of （Al＋Fe）/Si molar ratio, OH/（Al＋Fe） molar ratio （i.e., γ value）, coagulant dosage and pH value of test suspension on the coagulation behavior of FAFSiC and the stability of the PAFSiC were also examined. Results showed that PAFSiC performed more efficiently than PAC in removing turbidity, chemical oxygen demand （COD）, and total phosphate （TP）. The PAFSiC with a γ value of 2.0 and （Al＋Fe）/Si ratio of 5 （PAFSiC 2.0/5） showed excellent coagulation effect for both turbidity and COD, while PAFSiC 1.0/5 was the best for TP. The optimum coagulation pH range of PAFSiC 2.0/5 was 5.0–9.0, slightly wider than that of PAC （6.0–8.0）. The process can be easily incorporated into high-purity graphite production plants, thereby reducing wastewater pollution and producing a valuable coagulant.

Treatment of backwater in bauxite flotation plant and optimization by using Box-Behnken design

Flotation indexes gradually decrease with the increase of cycle time of the backwater in bauxite floatation,and discharge of backwater brings environmental risk.In this study,methods such as Fenton-oxidation,adsorption and coagulation were used in the treatment of backwater,the flotation indexes were checked after backwater treatments,and Box-Behnken design(BBD)was used in the optimization of the main operating parameters.The results reveal that flotation indexes are effectively improved after coagulation treatment by polyaluminum ferric chloride(PAFC).The optimum parameters predicted by BBD are pH 7.55,1.09 g/L PAFC dosage and temperature of 25℃.Under these optimum conditions,a maximum recovery of Al2O3 of 82.83%and a minimum A/S of 1.30 of tailings are gained,while the deviations are less than 3%from the predicted values.These findings encourage the application of BBD for the optimization of critical parameters in backwater treatment.

Effect of Water on Extractive Desulfurization of Simulated FCC Gasoline Using Ionic Liquid NMP-FeCl_(3)-H_(2)O

A series of novel aqueous ionic liquids(NMP-FeCl_(3)-nH_(2)O)were prepared and the effects of water in the aqueous ionic liquids on desulfurization rate and selectivity of simulated FCC gasoline were investigated.The results showed that adding a small amount of water into the ionic liquid NMP-FeCl_(3) could effectively improve the desulfurization rate and selectivity,and the optimal amount of water was equal to 5%-10% of NMP.Finally,the possible desulfurization mechanism activated by a small amount of water was proposed.

Nickel leaching from low-grade nickel matte using aqueous ferric chloride solution

Nickel leaching from low-grade nickel matte(LGNM) using aqueous ferric chloride solution was studied.The influence of factors such as leaching temperature and concentration of ferric chloride on the nickel leaching ratio was investigated.The results show that increasing leaching temperature and concentration of ferric chloride increases the nickel leaching ratio.The overall nickel leaching process follows the unreacted shrinking core model,and the surface chemical reaction is the rate-controlling step.The activation energy and the reaction order of the nickel leaching process,controlled by the surface chemical reaction,were calculated to be 52.96 kJ mol^(-1)and 0.5,respectively.Therefore,the kinetics equation for the nickel leaching was found to be 1-(1-α)^(1/3)=7.18×10~4C^(0.5)exp[-52,960/(RT)]t.

Removal of Turbidity and COD from a Synthetic Water Sample by Coagulation

The main objective of this research was to study the removal of turbidity and COD （chemical oxygen demand） from a synthetic water sample. The water sample was treated chemically by coagulation. Two inorganic coagulants were used, ferric chloride and the double salt potassium-aluminium sulphate. The optimum coagulant dosage and working pH were examined. The results for ferric chloride as coagulant showed that the maximum removal efficiency （%） of COD was achieved at pH 6 with a dosage of 100 mg-L-1 and the maximum removal efficiency （%） of turbidity at pH 5 with a dosage of 500 mg.L-1. For double salt, as coagulant, the maximum removal efficiencies （%） of COD and turbidity were achieved at pH 6 with a dosage of 3,500 mg.L-1. An extensive comparison with results from previous studies was also described in this research.

Synthesis and Characterization of Poly(N-Hexyl-2, 7-di(2-(4-hexylthiophene)carbazole)

One conjugated polymer consisting of carbazole and 3-hexylthiophene moiety, poly(N-Hexyl-2,7-di(2-(4-hexylthiophene)carbazole)(PNDC), has been synthesized by ferric chloride oxidative polymerization. The monomer N-Hexyl-2,7-di(2-(4-hexylthiophene)carbazole was synthesized and characterized by IR, 1H-NMR, 13C-NMR and MS. UV-vis absorption spectrum, fluorescence spectrum, photoluminescence spectrum and electrochemical properties of the polymer were investigated. Polymer PNDC shows maximum peak appearing at 394 nm in UV-vis absorption spectrum, strongest fluorescence-emission at 482 nm in fluorescence spectrum and maximum emission peak at 492 nm in photoluminescence spectrum. The band-gap(Eg), HOMO energy(EHOMO), and LUMO energy(ELUMO) of the polymer were obtained as 2.58,-5.32, and-2.74 e V, respectively.

A PRELIMINARY STUDY ON THE STABILITY OF TERNARY CoCl_2-FeCi_3 GRAPHITE INTERCALATION COMPOUNDS

The ternary CoCl2-FeCl3 graphite intercalation compounds (CoCl2-FeCl3 G/C) have been subjected to different treatments in various media. It is found that the CoCl2-FeCl3 GIC is stable 'when it is stored under conditions of opening to at-mosphere,whereas,acids,NaOH,boiling water,and heat treat-ments have different effects on the stability of the CoCl2-FeCl3 G/C.

System： Pattern of Phosphorus Sequestration in Different Depths of Sediment

The present study investigated potential effectiveness of certain chemical candidates for controlling internal phosphorus loading, and for delineating inactivation pattern in sediment depths of an eutrophic pond under simulated mesocosm condition. Chemical administration （@ 30 mg/dm3） resulted in phosphate precipitation from water column concomitant with inactivation in sediments, under specific pH range and/or redox regime. The alum-lime combination dosing wrought the maximum reduction in orthophosphate （65.6%） and soluble reactive phosphate （71.9%） in water plus the utmost increment in sediment-P （0.257 ppm）. The inactivated P forms typically exhibited a downhill concentration gradient with highest sequestration in the uppermost sediment stratum. Ironbound P displayed the highest mobility while calcium- and aluminum- bound P behaved almost immune to internal feedback dynamics. The combo-treatment was established as the most effective phosphate scavenging and confiscating agent, to be adopted as chemical remediation regime for de-eutrophication, restoration and rehabilitation of the water body.

Corrosion Study of Base Material and Welds of a Ni-Cr-Mo-W Alloy

Alloys containing chromium （Cr） and molybdenum （Mo）, as the major alloying elements, are widely used in various industries where the material experiences corrosive environments. Chromium （Cr）, when added in an optimum amount, forms a Cr203 passive film which protects the underlying metal in aggressive solutions. Molybdenum （Mo） forms its oxides in the low pH solutions, thus, enhances the uniform corrosion resistance of an alloy in reducing acids and assists in inhibition to localized corrosion. Minor alloying elements, like tungsten （W） and copper （Cu）, also improve the overall corrosion resistance of an alloy in specific solutions. In the present study, corrosion resistance behavior of commercial iron- based alloys （316L SS, 254 SMO and 20Cb3） and nickel-based alloys （Mone1400, Alloy 625 and C-276） was studied in the acidic solutions. While the corrosion behavior of wrought alloys has been widely studied, there is little to no information on the corrosion performance of their welds, typically being the weak regions for corrosion initiation and propagation. Therefore, an attempt was undertaken to investigate the uniform and localized corrosion performance of base metal, simulated heat-affected zone and all-weld-metal samples of a Ni-Cr-Mo-W alloy, C-276. The study was conducted in aggressive acidic solutions. Various corrosion and surface analytical techniques were utilized to analyze the results.

Diels-Alder Reactions of N-Functionalized Acryloyl α-Pyrrolidone Derivatives Using FeCl3·6H2O as an Efficient Catalyst under Solvent-free Conditions

Diels-Alder reactions of N-functionalized acryloyl α-pyrrolidone derivatives were investigated, which were catalyzed by FeCl3·6H2O as an efficient catalyst under solvent-free conditions at room temperature. The corresponding cycloadducts with functionalized-pyrrolidone were prepared in high yield with high stereoselectivity by a green chemistry procedure. N-Functionalized acryloyl pyrrolidone derivatives, a kind of pyrrolidone-functionalized chelating α,β-unsaturated ketone usable as a dienophile in Diels-Alder reaction, were synthesized by N-acylation procedure in ionic liquid as a novel synthetic method.

A coupled catalyst composed of CoFe_(2)O_(4) magnetic nanoparticle and[HMIM]Br-FeCl_(3) to intensify the oxidative desulfurization of FCC diesel

Ionic liquids have been extensively studied as solvents or catalysts for oxidative desulfurization(ODS)of diesel fuel,but it is still a challenge to reduce the desulfurization time and steps.In this work,a new highly efficient desulfurization system composed of CoFe_(2)O_(4) magnetic nanoparticle,[HMIM]Br-FeCl_(3) and H_(2)O_(2) was developed for the ODS of FCC diesel fuel.The desulfurization performances were investigated including desulfurization time,temperature,volume ratio of IL/oil,O/S molar ratio,dosage of CoFe_(2)O_(4),FeCl_(3) content in ILs,regeneration,and reuse of catalyst and solvent.Owing to the coupled catalytic roles of CoFe_(2)O_(4) magnetic nanoparticle and[HMIM]Br-FeCl_(3),where Co2t and Fe3t interact with H_(2)O_(2) to produce ·OH radical that converts S-compounds into sulfone and sulfoxide compounds,such a desulfurization system is highly effective in removing S-compound in diesel fuel.The S-content in FCC diesel fuel was reduced from the original 272.8 ppm to 0.5 ppm with 99.82%S-removal efficiency after one step within 8 minunder the optimal conditions of 25℃,8 min,V(IL/oil)=1:10,O/S=20,5 wt%CoFe_(2)O_(4) dosage and n([HMIM]Br)/n(FeCl_(3))=1:1;the desulfurization performance is much better in desulfurization time and steps than other desulfurization systems reported previously.The desulfurization system can be regenerated and reused without remarkable loss of desulfurization activity.A desulfurization mechanism was proposed.