A two-stage anaerobic system for biodegrading wastewater containing terephthalic acid and high strength easily degradable pollutants

The high strength easily biodegradable pollutants (represented by COD E) are strong inhibitors of terephthalic acid (TA) anaerobic biodegradation. At the same time, TA can inhibit easily biodegradable pollutants removal under anaerobic conditions to a limited extent. This mutual inhibition could happen and cause a low removal efficiency of both TA and COD E, when the effluent from TA workshops containing TA and easily biodegradable pollutants are treated by a single anaerobic reactor system. Based upon the treatment kinetics analysis of both TA degradation and COD E removal, a two stage up flow anaerobic sludge blanket and up flow fixed film reactor(UASB UAFF) system for dealing with this kind of wastewater was developed and run successfully at laboratory scale. An UASB reactor with the methanogenic consortium as the first stage removes the easily biodegradable pollutants(COD E). An UAFF reactor as the second stage is mainly in charge of TA degradation. At a COD E loading of 15.3 g/(L\5d) and a TA loading of 1.4 g/(L\5d), HRT 18.5h, the COD E and TA removal rate of the system reached 89.2% and 71.6%, respectively.

Towards recycling purpose:Converting PET plastic waste back to terephthalic acid using pH-responsive phase transfer catalyst

Converting polyethylene terephthalate(PET)wastes to its monomer and valuable chemicals via ecofriendly chemical method is still a challenge task.Previously,phase transfer catalysts used for alkaline hydrolysis were soluble in reaction media and hardly separated after reaction.Here,we reported several pH-responsive catalysts combined alkyl quaternary ammonium units with heteropolyacid anion for achieving stepwise product/catalyst separation and catalyst recycling.The properties of homogeneous/heterogeneous transfer behavior allow catalyst to be easily separated from reaction media by adjusting of pH value.Among them,[C_(16)H_(33)N(CH_(3))_(3)]_(3)PW_(12)O_(40)(abbreviated as[CTA]_(3)PW)exhibits the highest activity and the most suitable pH responsive values.Such a pH triggered switchable catalytic system not only shows good performance for depolymerization of pure PET,but also some real PET wastes such as coloured trays and PE/PET complex films could be completely degraded into terephthalic acid.Additionally,the reaction kinetics and activation energy of PET alkaline hydrolysis also studied with and without pH-responsive[CTA]_(3)PW.

Kinetics of the Mono-esterification Between Terephthalic Acid and 1,4-Butanediol

The chemical kinetics of the monoesterification between terephthalic acid(TPA)and 1,4-butanediol (BDO)catalyzed by a metallo-organic compound was studied using the initial rate method.The experiments were carried out in the temperature range of 463-483 K,and butylhydroxyoxo-stannane(BuSnOOH)and tetrabutyl titanate[Ti(OBu)4]were used as catalyst respectively.The initial rates of the reaction catalyzed by BuSnOOH or Ti(OBu)4 were measured at a series of initial concentrations of BDO(or TPA)with the concentration of TPA(or BDO)kept constant.The reaction orders of reagents were determined by the initial rate method.The results indicate that the reaction order for TPA is related with the species of catalyst and it is 2 and 0.7 for BuSnOOH and Ti(OBu)4 respectively.However,the order for BDO is the same 0.9 for the two catalysts.Furthermore,the effects of temperature and catalyst concentration are investigated,and the activation energies and the reaction rate constants for the two catalysts were determined.

Synthesis and Characterization of Poly(terephthalic acid-2,5-furandicarboxylic acid-1,8-octanediol) Copolyester

Terephthalic acid,2,5-furandicarboxylic acid and 1,8-octanediol were adopted as monomers and antimony trioxide as catalyst,and poly(terephthalic acid-2,5-furandicarboxylic acid-1,8-octanediol) copolyesters identified as PEOT-x,where x is the mole fraction of furandicarboxylic acid in the samples,were synthesized by direct esterification.The molecular structure of the copolyesters was characterized by FTIR and 1H NMR spectroscopy.Gel permeation chromatography (GPC),differential scanning calorimetry (DSC),and thermogravimetric analysis (TGA) were used to characterize the molecular weight,molar mass dispersity,glass transition temperature,and thermal stability of the copolyesters,respectively.The mechanical properties of the samples were also investigated.The number-average molecular weight (M_(n)) of the samples varies from 9 700-18 800 g/mol,and molar mass dispersity (■=M_(w)/M_(n)) from 2.15-3.34.The initial decomposition temperature of the copolyesters is in the 332-356 ℃ range,with maximum decomposition rates at 390-410 ℃,while the glass transition temperature (Tg) varies from 0-33 ℃.Mechanical test shows that PEOT-10 has the highest tensile strength,while PEOT-90 has the largest tensile modulus and elongation at break.The experimental results show that these copolyesters can be synthesized with relatively high molecular weights,good thermal stability,and fair mechanical properties,which makes them excellent replacements for commercial polyesters,such as PET,and these properties can be tuned through the relative amounts of biomass monomer 2,5-furandicarboxylic acid used in the reactions.

Research and Implementation of Decreasing the Acetic Acid Consumption in Purified Terephthalic Acid Solvent System

减少在净化的对苯二酸酸(PTA ) 的醋酸消费溶剂系统与普通担心成为了一个热问题。根据技术特征，电的传导性在到醋酸内容的直接比例。一般回归神经网络(GRNN ) 被用来与惯性重量的改进根据机制分析，然后粒子群优化(PSO ) 算法建立电的电导率的模型，人口差异被建议调整操作条件。因此，酸损失被导出并且在一家化学工厂适用于 PTA 溶剂系统的减少的方法。案例研究证明当模特儿和优化的精确更高。结果也提供最佳的操作条件，它减少花费并且改善利润。

Solvothermal Synthesis,Crystal Structure and Photoluminescence Property of a 3D Lead(Ⅱ)Coordination Polymer Based on Terephthalic Acid

Solvothermal reaction of Pb（NO3）2·6H2O with rigid linear ligand terephthalic acid（H2pta） in N,N-dimethylformamide（DMF） produced a new three-dimensional（3D） lead（Ⅱ）coordination polymer[Pb2（pta）1.5（μ4-OH）（DMF）]n 1,and its structure was characterized by single-crystal X-ray diffraction analyses.In polymer 1,the μ4-OH bridges the nearby lead（Ⅱ） ions into an infinite one-dimensional（1D） chain,and then the organic ligand pta^2- joins the neighbored chains into a 3D structure by two similar connection modes in different configurations.The solid-state photoluminescent studies revealed that 1 exhibits a strong greenish emission mainly originating from ligand-to-metal charge transfer between the delocalized π bonds of the aromatic carboxylate ligand pta^2- and the p orbitals of the Pb^2＋ centers.

Effects of Terephthalic Acid on Rat Lipid Metabolism

Objective To study the effect of terephthalic acid （TPA） on lipid metabolism in Sprague-Dawley （SD） rats. Methods Five groups of SD rats that ingested 0%, 0.04%, 0.2%, 1%, and 5% TPA, respectively, were included in a 90-day subchronic feeding study. Effects of TPA on levels of serum protein, total cholesterol （TC）, triglycerides （TG）, high-density lipoprotein cholesterol （HDL）, total antioxidative capability （T-AOC）, superoxide dismutase （SOD） and malondialdehyde （MDA） were observed. Urine samples were collected and analyzed for concentration of ion. Results TPA decreased the level of serum T-AOC in a dose dependent manner. The contents of serum and bladder MDA significantly decreased in 1% and 5% TPA ingestion groups. Serum CuZn superoxide dismutase （CuZnSOD） lowered in groups of 0.2%, 1%, and 5% TPA. TPA subchronic feeding had no significant influences on serum TC, LDL or HDL, but increased serum TG, TP and ALB after administration of 0.04% and/or 0.2% TPA. Concentrations of urinary Ca^2＋, Mg^2＋, Na^＋, and K^＋ were elevated in 1% and 5% TPA groups. Conclusion Antioxidative potential decreased after TPA exposure. MDAincrease in serum and bladder tissues was one of the most important reactions in rats which could protect themselves against TPA impairment. The decrease of serum CuZnSOD was related to the excretion of Zn^2＋.

Metabolism of Terephthalic Acid and Its Effects on CYP4B1 Induction

Objective To investgate the metabolism of terephthalic acid （TPA） in rats and its mechanism. Methods Metabolism was evaluated by incubating sodium terephthalate （NaTPA） with rat normal liver microsomes, or with microsomes pretreated by phenobarbital sodium, or with 3-methycholanthrene, or with diet control following a NADPH-generating system. The determination was performed by high performance liquid chromatography （HPLC）, and the mutagenic activation was analyzed by umu tester strain Salmonella typhimurium NM2009. Expression of CYP4B 1 mRNA was detected by RT-PCR. Results The amount of NaTPA （12.5-200 μmol-L^1） detected by HPLC did not decrease in microsomes induced by NADPH-generating system. Incubation of TPA （0.025-0.1 mmol-L^-1） with induced or noninduced liver microsomes in an NM2009 umu response system did not show any mutagenic activation. TPA exposure increased the expression of CYP4B1 mRNA in rat liver, kidney, and bladder. Contusion Lack of metabolism of TPA in liver and negative genotoxic data from NM2009 study are consistent with other previous short-term tests, suggesting that the carcinogenesis in TPA feeding animals is not directly interfered with TPA itself and/or its metabolites.

Comparative study of thermophilic and mesophilic anaerobic treatment of purified terephthalic acid (PTA) wastewater

The paper provides a critical comparison between mesophilic and thermophilic anaerobic treatment of PTA wastewater through diagnosis of a case study. Aspects covered are bioavailability, biodegradability, microbial population, thermodynamics, kinetics involved and bio-reactor design for PTA wastewater treatment. The results of the case study suggests that one- stage thermophilic anaerobic reactor coupled with coagulation-flocculation pre-treatment unit and an aerobic post treatment unit could be techno-economically viable for PTA wastewater treatment to ensure that the final effluent quality conforms to the international standard. The in-formation emanated from this study could be useful and thought provoking to the professionals and academia in the area of PTA wastewater treatment and can serve as impetus toward the development of research lines in similar problems like the treatment of other petrochemical wastewater such as phenol-con- taining wastewater, benzene/benzoic acid-con- taining wastewater or wastewater from other similar industrial settings.

Biodegradability of terephthalic acid in terylene artificial silk printing and dyeing wastewater

As the characteristic pollutant, terephthalic acid(TA)was in charge of 40%—78% of the total COD of terylene artificial silk printing and dyeing wastewater(TPW-water). The studies on biodegradability of TA were conducted in a serial of activated sludge reactors with TPW-water. TA appeared to be readily biodegradable with removal efficiency over 96.5% under aerobic conditions, hardly biodegradable with removal efficiency below 10% under anoxic conditions and slowly biodegradable with a turnover between 31.4% and 56.0% under anaerobic conditions. TA also accounted for the majority of BOD in TPW-water. The process combined by anoxic, anaerobic and aerobic activated sludge reactor was suitable for TA degradation and TPW-water treatment. Further, the aerobic process was essentially much more effective than the anaerobic or anoxic one to degrade TA in TPW-water.

Anaerobic biodegradability of terephthalic acid and its inhibitory effect on anaerobic digestion

The behavior of terephthalic acid (TPA) in anaerobic system has been studied bysemicontinuous bioassays under mesophilic condition with artificial TPA production wastewater. Theeffect of different loading rate of TPA on anaerobic digestion was studied under certain CODloading rate. The results showed that the TPA could be degraded anaerobically within a relativelylow range. The degradable concentration of TPA was less than 500 mg/L in the digester, higherconcentration of TPA could not be degraded totally and the rate of degradation might decrease withthe increase of feed amount. The inhibition is related to both loading rate and accumulatedconcentration of TPA in the digesters.

Purified terephthalic acid wastewater biodegradation and toxicity

The biodegradation and toxicity of the purified terephthalic acid（PTA） processing wastewater was researched at NJYZ pilot with the fusant strain Fhhh in the carrier activated sludge process（ CASP）. Sludge loading rate（SLR） for Fhhh to COD of the wastewater was 1.09 d^-1 and to PTA in the wastewater was 0.29 d^-1. The results of bioassay at the pilot and calculation with software Ebis3 showed that the 48h-LC50 （median lethal concentration） to Daphnia magna for the PTA concentration in the wastewater was only 1/10 of that for the chemical PTA. There were .5 kinds of benzoate pollutants and their toxicities existing in the wastewater at least. The toxicity parameter value of the pure chemical PTA cannot be used to predicate the PTA wastewater toxicity. The toxicity of the NJYZ PTA wastewater will be discussed in detail in this paper.

Synthesis and identification of dinitro- and diaminoterephthalic acid

Dinitroterephthalic acid （DNTPA） and diaminoterephthalic acid （DATPA） were prepared in 85% and 75% yields, respectively. These compounds were characterized by using FTIR and ^1HNMR. DATPA can be used as a monomer for the preparation of polyesters and polyamides. 2009 H. Migbani. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Solid-Liquid Equilibrium of Terephthalic Acid in Several Solvents

Terephthalic acid(PTA) is practically one of the main materials of polyester. Its corresponding solid-liquid equilibrium data will provide essential support for industry design and further theoretical studies. In this work,solid-liquid equilibriums of terephthalic acid in four solvents, N,N-dimethylformamide, N,N-dimethylacetamide,dimethylsulphoxide and N-methyl-2-ketopyrrolidene, were determined in the temperature range from 293.15 K to 364.6 K by dynamic method. All these data were regressed by λh model, Wilson model and NRTL model, average absolute relative deviations of which are 1.25%, 15.02% and 7.22% respectively. It indicates that λh model is mostsuitable for description of the solid-liquid equilibrium containing PTA.

Spectrofluorimetric determination of terbium with terephthalic acid

A Spectrofluorimetric method has been developed for the determination ofterbium(Ⅲ) based on the formation of a complex with terephthalic acid [benzene-1, 4-dicarboxylicacid (TPA)] in slightly acidic aqueous solution in the presence of gelatin. Terbium ion can form astable complex with TPA with the stoichiometry of 1:2. The best excitation and maximum emissionwavelengths are observed at 260 nm and 545 nm, respectively. The fluorescence intensity of terbiumcomplex gets the strongest within 20 min and remains stable up to 10 h, and it is proportional toterbium(Ⅲ) concentration in the range of 4.0x10^(-5)-1.6x10^(-7) mol·L^(-1) under the optimumconditions. The fluorescence system has good selectivity, sensitivity and stability. The relativestandard deviation is still within +-4% in the presence of 1200-fold amounts of the other lanthanideions when the concentration of terbium(Ⅲ) is 1.0x10^(-6) mol·L^(-1) and common co-existing ionshardly interfere the determination. It has been applied to the direct fluorimetric determination oftrace terbium (Ⅲ) in rare earth ores and oxides.

Induction of Bladder Lesion by Terephthalic Acid and Its Mechanism

To provide more information for rational evaluation of potential risks of terephthalic acid （TPA）, we studied the effects of TPA on rats＇ bladders in 90 days after TPA exposure. Methods Sprague Dawley rats were subdivided into five groups, ingesting 0 %, 0.04 %, 0.2 %, 1%, and 5 % TPA respectively for a sub-chronic feeding study lasting for 90 days. Urine, serum and samples of brain, liver, lung, kidney, bladder, etc. were collected and analyzed. Results TPA ingesting decreased the value of urinary pH, and increased the contents of Ca^2＋, Zn^2＋, Mg^2＋, Na^＋, K^＋ in urine. The volume of 24 h urine was significantly increased in male rats in the 1% and 5 % TPA groups. Urinary white sediment was found in both sexes, and its formation in male rats seemed more susceptible than that in female rats. Alpha 2u-globulin （AUG） in serum and urine of male rats was markedly increased in a dose-dependent manner. Fifteen cases of hyperplasia （simple or atypical） were determined in the 5 % TPA ingesting group, 14/52 in male rats and 1/23 in female rats. Among them 3 male rats had no stone or calculus. Those with either bladder stones or hyperplasia were accompanied with urinary white sediments. Conclusion White sediment accompanied with elevated urine AUG is the basis of TPA induced urolith formation, and is also associated with TPA induced bladder epithelial cell proliferation. It can act as an early biomarker for the potential toxic effect of TPA.

Dynamic Simulation and Analysis of Industrial Purified Terephthalic Acid Solvent Dehydration Process

为工业净化的对苯二酸酸溶剂的脱水过程的动态模型被调查理解并且描绘这个过程。温度微分表示被介绍，它保证方程到集中和短计算时间。模型被用来学习作为 entrainer 分开醋酸和水使用 n 丁基醋酸盐的 azeotropic 蒸馏列的动态行为。列的回答被模仿喂流动和水的倒流流动。温度前面的运动也被模仿。在模拟和工业价值之间的比较证明模型和算法是有效的。根据模拟和分析，控制策略，联机优化能等等在净化的对苯二酸酸的脱水过程有效地被实现溶剂。

Multi-objective Optimization of Industrial Purified Terephthalic Acid Oxidation Process

Multi-objective optimization of a purified terephthalic acid (PTA) oxidation unit is carried out in this paper by using a process model that has been proved to describe industrial process quite well. The model is a semiempirical structured into two series ideal continuously stirred tank reactor (CSTR) models. The optimal objectives include maximizing the yield or inlet rate and minimizing the concentration of 4-carboxy-benzaldhyde, which is the main undesirable intermediate product in the reaction process. The multi-objective optimization algorithm applied in this study is non-dominated sorting genetic algorithm Ⅱ(NSGA-Ⅱ). The performance of NSGA-II is further illustrated by application to the title process.

Fuzzy Neural Network Model of 4-CBA Concentration for Industrial Purified Terephthalic Acid Oxidation Process

A fuzzy neural network (FNN) model is developed to predict the 4-CBA concentration of the oxidation unit in purified terephthalic acid process. Several technologies are used to deal with the process data before modeling.First,a set of preliminary input variables is selected according to prior knowledge and experience. Secondly,a method based on the maximum correlation coefficient is proposed to detect the dead time between the process variables and response variables. Finally, the fuzzy curve method is used to reduce the unimportant input variables.The simulation results based on industrial data show that the relative error range of the FNN model is narrower than that of the American Oil Company (AMOCO) model. Furthermore, the FNN model can predict the trend of the 4-CBA concentration more accurately.

Syntheses and cofluorescence of complexes of Eu(Ⅲ)/Y(Ⅲ) with terephthalic acid, 2-thenoyltrifluoroacetone and trioctylphosphine oxide

A series of Eu( Ⅲ )/Y( Ⅲ ) complexes of terephthalic acid(TPA) with 2-thenoyltrifluoroacetone(HTTA) and trioctylphosphine oxide(TPPO) were synthesized. Compositions of these complexes are revealed to be Eu2(1-x)Y2x(TPA)(TTA)4- (TPPO)4 or Eu1-xYx(TPA)(TTA)(TPPO)2. Their IR spectra, fluorescent spectra and the thermal and optical stability were studied. The fluorescent excitation spectra of these complexes show more broad excitation bands than those of Eu2(TPA)3(TPPO)4 and Eu(TTA)3(TPPO)2 corresponding to their formations. In addition, both the binuclear complex EuY(TPA)(TTA)4(TPPO)4 and the chain complex Eu0.4Y0.6(TPA)(TTA)(TPPO)2 present higher thermal stability and better optical stability than the mononuclear complex Eu(TTA)3(TPPO)2 does. And their thermal and optical stabilities are preferably interpreted from the binuclear structure together with the chain polynuclear structure of the complexes. The fluorescence enhancement of cofluorescence Y3+ ions to the Eu(Ⅲ) complexes is clear. The optimum content of Y3+ is 0.6 (molar fraction) for the chain complexes Eu1-xYx(TPA)(TTA)- (TPPO)2 and 0.5 for the binuclear complexes Eu2(1-x)Y2x(TPA)(TTA)4(TPPO)4. The formation of polynuclear structure of the complex Eu1-xYx(TPA)(TTA)(TPPO)2 appears to be responsible for the good cofluorescence effect of Y3+ ions.