Difficulty Of Separation Research Articles

Liquid mixtures separation and heat consumption in the process of distillation

Objectives. The aim of this study is to investigate different distillation modes of a binary ideal mixture and determine how various factors affect heat consumption in the column boilers. In addition, it intends to assess the difficulty of separating mixtures. Our research is based on analyzing the characteristics of vapor-liquid equilibrium.Methods. To conduct our study, we used a graphic-analytical tool to calculate the distillation process of a binary mixture and mathematical models based on the Aspen Plus software package along with DSTWU, RadFrac, and the Sensitivity module. We also used the Peng-Robinson equation (PENG-ROB) to determine the liquid-vapor equilibrium.Results. We employed the graphical method and mathematical models to obtain the operation parameters of two column variants for the distillation of binary ideal benzene-toluene mixtures. In each variant the initial mixture contained the same amount of the low- and high-boiling component. The number of plates in the column sections, reflux ratio, energy consumption, and indicators of internal energy saving were determined.Conclusions. Study results show that using the coefficient of the component distribution between the vapor and liquid phases is a promising method for preliminary assessments of the separation difficulty and measurements of the expected heat consumption in the boilers of columns. Comparison studies showed that the heat consumption in the boiler decreases as the internal energy saving in the columns increases.

Separating mechanism of dandelion (Taraxacum officinale) seed: Results from model analysis and separation force measurement

Dandelion seeds can be elegantly released by a gentle wind, but their separating mechanism has not been revealed. Here, we investigated the separating mechanism via structure observation, model analysis and separation force measurement. Connecting region of a dandelion seed includes barbs distributed on the inserting region of achene and groove of the inflorescence head. The barbs have conical morphology with a length of 42–50 μm, and the groove has plenty of wrinkles to enhance its wrapping ability. Based on structure characteristics of the connecting region, we established a model to analyze the mechanical properties produced by barbs and wrinkles during their separation. Model result confirmed that the barbs in different part of the inserting region have considerable difference in degree of separation difficulty, and the calculated separation force decreases sharply when the separation angle increases from 20° to 80°. The measured separation force (10.67–0.35 mN) showed almost the same change tendency as the calculated separation force, confirming the validity of our established model. Our study reveals the separating mechanism of dandelion seeds, and provides an approach for the biomimetic design of controllable attachment/release device used in the field of mechanical engineering.

Production of Biodiesel from Desert Date Seed Oil Using Heterogeneous Catalysts

In the recent time, there is increasing research in the area of alternative fuels as the exhausts of presently used petroleum-based fuels have been identified to have negative effects on the environment. Fuels produced from plant oils and animal fats have the tendencies of replacing petro fuels since they are renewable in nature. One of these renewable fuels is biodiesel. However, the homogenous catalyst used in biodiesel production has some drawbacks such as difficulty in separation from the fuel, soap formation and corrosiveness of the product mixture. In this work, the use of heterogeneous catalyst sourced from local raw materials (kaolin and eggshell) for the production of biodiesel from oil of desert date seed has been investigated. The kaolin obtained from Alkaleri Mining Site, Bauchi, was calcined in an oven at 800 °C for 3 h. The calcined kaolin was then chemically activated. Also, the eggshell-based catalyst was produced from raw eggshells after washing, drying, grinding, sieving using 0.3 mm sieve size and calcining at 900 °C for 3 h. Furthermore, the oil content of the desert date seed, which was acquired from a local market in Bauchi, was extracted via solvent extraction in a laboratory with a yield of 42%. Then, the biodiesel was subsequently prepared by mixing the oil, methanol and catalyst in a flat bottom flask and heating the mixture for a specified period. The catalyst concentration, methanol to oil ratio and time of reaction were subsequently varied to obtain the best yield. The results obtained revealed that an optimum yield of 29% could be obtained at methanol to oil ratio of 6:1 and a reaction time of 60 min using 1.5 g of eggshell-based catalyst while an optimum yield of 22% was obtained with 0.6 g for kaolin-based catalyst at a reaction time of 60 min and methanol to oil ratio of 4:1. It is recommended that further work should be carried out to improve on the yield of the biodiesel obtained using the heterogeneous catalysts.

Treatment of wastewater reverse osmosis concentrate using alginate-immobilised microalgae: Integrated impact of solution conditions on algal bead performance

Alginate can be used for entrapment of microalgal cells in gel beads to achieve high-rate treatment of wastewater and can overcome the difficulties of cell separation that would occur in suspended microalgae treatment systems. The potential for alginate beads to disintegrate in the presence of high ion concentrations could limit the use of alginate entrapment for treating municipal wastewater reverse osmosis concentrate (ROC). The combined effect of the pH, alkalinity, and salinity of the ROC that impact the physical stability, chemical characteristics, biomass production, and nutrient removal performance of alginate-entrapped Chlorella vulgaris for treating the ROC was investigated. Water adsorption resulting from the loss of calcium from the alginate matrix was the initiating cause of reduction of the algal bead stability. The combination of alkalinity >400 mg/L and pH ≥9.5 led to a >65% reduction in compressive strength and thus disintegration of beads during ROC treatment. However, alginate beads of C. vulgaris were sufficiently stable and were capable of nutrient remediation (up to 100% TP and 85% TN per treatment cycle of 48 h over a 10-day period) and biomass production (up to 340 mg/L/d) when salinity, pH, and alkalinity levels were <8 g TDS/L, 7–9.5, and <400 mg/L, respectively. Empirical models that were developed and validated could enable the prediction of the performance of the algal beads for various ROC compositions. This study enhances the insight and decision-making regarding the feasibility of the alginate-immobilised microalgal system for treating municipal wastewater ROC streams.

LiMn2O4 prepared from waste lithium ion batteries through sol-gel process

Abstract The core issues that restrict the recycling of waste lithium-ion batteries (LIBs) are the difficulty of separation and the secondary pollution that occurs during the recycling process. In this paper, new LiMn2O4 (LMO) was prepared directly from the leaching solution of waste LIBs, which avoided the complex separation process. Citric acid was used as the leaching reagent, and glucose was used as the reducing agent. The structural properties of the resynthesized LMOs calcined at different temperatures were studied by X-ray diffraction (XRD) and further refined by the Rietveld method. XRD and Rietveld refinement confirmed that all the samples had cubic spinel structures, and the lattice parameters increased with increasing temperature. The surface morphology of the final products was characterized by SEM, TEM and XPS to determine the crystal structure, morphology and surface chemical constitution. The electrochemical properties were also tested. The results showed that the new LiMn2O4 prepared from waste LIBs possessed good electrochemical properties, and this method for recycling waste lithium-ion batteries is feasible.

Multiple Functions of Gas Separation and Vapor Adsorption in a New MOF with Open Tubular Channels

Separation or purification is one of the difficult problems in the petrochemical industry. To help solve the difficulty of separation or purification for C2H2/CO2 and C2Hn/CH4 in the chemical industry, we synthesized a new metal-organic framework (MOF), [Ni(dpip)]·2.5DMF·H2O (1), by a bipyridyl-substituted isophthalic acid ligand. The MOF includes two types of one-dimensional (1D) tubular channels with different sizes and porous environments. The unique tubular channels lead to not only remarkable gas sorption capacity of C2H4, C2H2, and CO2, but also good selectivity for C2H2/CH4, C2H2/CH4, CO2/CH4, and C2H2/CO2, as demonstrated by single-component sorption isotherm results, ideal adsorbed solution theory calculations, and dynamic breakthrough curves. Grand canonical Monte Carlo (GCMC) simulation reveals preferential adsorption sites in the MOF for CO2, C2H2, and C2H4. The MOF also exhibits an obvious size-selective absorption effect on vapor molecules.

Searching for a sliver of space: working psychotherapeutically with autistic states

ABSTRACT This paper explores the emotional and mental barriers autistic children may face in the process of relating to other people as separate individuals. Clinical examples will illustrate these difficulties as they manifested in the therapeutic relationship and in the separation anxiety of two autistic patients. I will also explore the working through of the children’s separation difficulties in their relationship with the therapist. This work entailed both understanding the nature of the patients’ anxiety, as well as actively searching for a sliver of space for the therapist, which the children could tolerate. The work with one patient, who had more pronounced autistic symptoms and was non-verbal for many years, centred on forming bodily-physical separation. The work with the moderately symptomatic patient, who was verbally fluent, focused on tolerating ideational differentiation between him and the therapist. The children’s separation dread was understood by considering both psychoanalytic and neuro-cognitive models of autism. As these issues were worked through, the nature of the therapeutic relationship changed, from mainly consisting of an adhesive connection with the therapist, to more communicative, emotional and personal interactions. The discussion will address the way that the therapist’s use of her body and personality motivated the patients to relate with, rather than adhere to her.

Development of a schwarzite-based moving bed 3D printed water treatment system for nanoplastic remediation.

The impact of micro and nanoplastic debris on our aquatic ecosystem is among the most prominent environmental challenges we face today. In addition, nanoplastics create significant concern for environmentalists because of their toxicity and difficulty in separation and removal. Here we report the development of a 3D printed moving bed water filter (M-3DPWF), which can perform as an efficient nanoplastic scavenger. The enhanced separation of the nanoplastics happens due to the creation of a charged filter material that traps the more surface charged nanoparticles selectively. Synthetic contaminated water from polycarbonate waste has been tested with the filter, and enhanced nanoplastic removal has been achieved. The proposed filtration mechanism of surface-charge based water cleaning is further validated using density function theory (semi-empirical) based simulation. The filter has also shown good structural and mechanical stability in both static and dynamic water conditions. The field suitability of the novel treatment system has also been confirmed using water from various sources, such as sea, river, and pond. Our results suggest that the newly developed water filter can be used for the removal of floating nanoparticles in water as a robust advanced treatment system.

Method of Partnership with the Private Sector in Iraq

The topic of public-private partnerships has been received with great interest by governments, societies and research centers around the world. After it became clear that the process of economic and social development is based on mobilizing and gathering all the potentials of society, including the energies, resources and experiences of both the public and private sectors, to participate in the institutional organizations that deal with the establishment and operation of projects of various kinds after the institutional arrangements faced separate and independent sectoral challenges and difficulties. In achieving the goals of development levels is an ambitious goal. Therefore, developed countries seek to develop institutions, legislation and institutional systems to adopt participatory organizations in which all sectors of society contribute to directing, managing and operating projects and businesses, developing and developing them in order to serve their purposes on the basis of cooperative participation, good governance, transparent accountability and mutual benefit. The success of the partnership is not limited to ensuring legislation and regulations only, but links must be established between it and the concept of governance. Both have multiple aspects related to administrative, legal, economic and social dimensions that meet at common points based on the principles of transparency, disclosure and accountability, and equal rights of stakeholders and responsibilities in order to raise the efficiency of resource use, enhance competitiveness, attract funding sources, and expand projects to create new job opportunities and support economic stability. The topic of public-private partnerships has been received with great interest by governments, societies and research centers around the world. After it became clear that the process of economic and social development is based on mobilizing and gathering all the potentials of society, including the energies, resources and experiences of both the public and private sectors, to participate in the institutional organizations that deal with the establishment and operation of projects of various kinds after the institutional arrangements faced separate and independent sectoral challenges and difficulties. In achieving the goals of development levels is an ambitious goal. Therefore, developed countries seek to develop institutions, legislation and institutional systems to adopt participatory organizations in which all sectors of society contribute to directing, managing and operating projects and businesses, developing and developing them in order to serve their purposes on the basis of cooperative participation, good governance, transparent accountability and mutual benefit. The success of the partnership is not limited to ensuring legislation and regulations only, but links must be established between it and the concept of governance. Both have multiple aspects related to administrative, legal, economic and social dimensions that meet at common points based on the principles of transparency, disclosure and accountability, and equal rights of stakeholders and responsibilities in order to raise the efficiency of resource use, enhance competitiveness, attract funding sources, and expand projects to create new job opportunities and support economic stability. Many researchers believe that the issue of partnership is still in its early stages of developing unified principles, rules and regulations that govern and regulate the various forms of partnerships between the public and private sectors to include all economic and social sectors as major topics. The concept, principles and standards are still being sought to develop, elaborate and categorize them in order to be placed in specific rules and frameworks.

A sustainable way to reuse Cr(VI) into an efficient biological nanometer electrocatalyst by Bacillus megaterium

The remediation of heavy metal is facing the great challenge of failing to achieve valuable transformation. Therefore, the development of a sustainable technology for heavy metal recycling and reuse is essential. The present study proposed a new way to convert Cr(VI) into value-added biological Cr2O3 nanoparticles (bio-Cr2O3 NPs) with B. megaterium-secreted tryptophan residues proteins (TPN). In this process, Cr(VI) was reduced extracellularly to Cr(III) by B. megaterium without additional reductant and electron donors. This study overcomes the difficulty of separation of NPs and biomass, and realizes the recovery of bio-Cr2O3 NPS from biomass. The conversing efficiency of bio-Cr2O3 NPs reached the highest level (96.56%) at the concentration of 10 ppm Cr(VI). In particular, bio-Cr2O3 NPs exhibited excellent catalytic activity for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in 1 M KOH, outperforming chemically synthesized Cr-base catalysts. Three-dimensional matrix fluorescence (EEM), verification of tryptophan reduction and computation chemistry fully confirmed that TPN was responsible for the bio-Cr2O3 NPs formation. This comprehensive approach to bioremediation, synthesis NPs and recovery, as well as application will open a window for sustainable energy development and heavy metal pollution remediation.

Adsorption of Diazo Dye from Aqueous Solutions by Magnetic Montmorillonite Composite

AbstractSynthetic dyes have complex molecular structures and are stable molecules against oxidizing agents, sunlight, and microbial attack. Therefore, the treatment of dye‐containing wastewater using appropriate techniques is of great importance. Difficulties in separation and recovery of an adsorbent from the solution limit the large‐scale applications of the adsorption process. A magnetic separation technique can be adapted to the adsorption process to overcome these limitations. In this study, a natural mineral‐based magnetic adsorbent is prepared by a co‐precipitation method. Adsorption performance of magnetic montmorillonite (MagMt) is evaluated in both batch and continuous systems as a function of initial pH, contact time, adsorbent dosage, ionic strength, flow rate, and bed depth. MagMt is characterized through infrared (IR) spectroscopy, scanning electron microscopy (SEM), energy dispersive X‐ray analysis (EDX), vibrating sample magnetometer (VSM), X‐ray diffraction (XRD), and zeta potential measurement. Sorption yield of MagMt for Bismark Brown‐Y (BB‐Y) is found as maximum (98.60%) at pH 4 with 40 mg adsorbent. Fast sorption equilibrium is attained within 10 min and the sorption data follow the pseudo‐second‐order kinetic model and Langmuir isotherm model. The maximum monolayer sorption capacity of MagMt is 138.70 mg g‒1.

Kinetics and mechanistic aspects of removal of heavy metal through gas-liquid sulfide precipitation: A computational and experimental study

The production of fine particles from extremely high supersaturation has challenged the application of sulfide precipitation in treating heavy metal wastewater due to the difficulty of solid-liquid separation. To this end, a gas-liquid sulfide precipitation reactor for the removal of Cu2+ was designed by controlling the mass transfer and supersaturation levels during sulfidation processes. Particularly, a computational fluid dynamics (CFD) model of the reactor, integrating sulfidation reaction kinetics with two-phase flow hydrodynamics, was first built, followed by examining the effects of H2S(g) bubble diameter and flow rate. Based on the CFD simulation, the rate-limiting step of the gas-liquid sulfide precipitation reaction is the gas-liquid mass transfer process. Either reducing H2S(g) bubble diameter or increasing H2S(g) flow rate can result in the control of reaction rate and supersaturation level in the system. In order to validate the CFD simulations, we measured Cu2+ concentrations during the sulfidation process with the batch experiments. The agreement between computational and experimental results indicated that our mechanistic model can provide a protocol for the design and optimization of the reaction system, allowing one to visualize the time-dependent reaction process and evaluate the performance of a reactor.

Fabrication of NanoCOF/Polyoxometallate Composites for Photocatalytic NADH Regeneration via Cascade Electron Relay

Covalent organic frameworks (COFs) as novel visible‐light responsive photocatalysts confront the problem of low photocatalytic activity due to the difficulty in separation of photogenerated charge carriers. Herein, the fabrication of nanoCOF/polyoxometallate (POM) composites to enhance the charge separation efficiency via cascade electron relay is reported. It is found that the photogenerated electrons in the π orbitals of nanoCOF quickly transfer to POM (electron mediator and electron storage tank) to form heteropolyblue (HPB), which is verified by electron paramagnetic resonance and ultraviolet (UV)–vis characterizations. In photocatalytic NADH regeneration, nanoCOF/POM composites afford NADH yield of 97% with turnover frequency of 72.0 mmolgCOF−1 h−1, which is the highest ever reported for COFs and is more than 360‐fold that of COF counterpart. The high photocatalytic activity of nanoCOF/POM composites is mainly attributed to the high concentration of charge carriers and long lifetime of photogenerated charges on the basis of transient absorption spectroscopy, which are achieved by the cascade relay of photogenerated electrons. The primary results suggest that the integration of COFs with electron mediators is an efficient approach to increase the photocatalytic activity via promoted charge separation efficiency.

Renieramycin-type alkaloids from marine-derived organisms: Synthetic chemistry, biological activity and structural modification.

Marine natural products are known for their diverse chemical structures and extensive bioactivities. Renieramycins, the member of tetrahydroisoquinoline family of marine natural products, arouse interests because of their strong antitumor activities and similar structures to the first marine antitumor agent ecteinascidin-743, approved by the European Union. According to the literatures, researches on the pharmacological activities of renieramycins mainly focus on their antitumor activities. In addition, by structural modification, derivatives of renieramycins show stronger antiproliferative activity and less accidental necrosis activity on cells. Nevertheless, the difficulties in extraction and separation hinder their further development. Hence, the synthetic chemistry work of renieramycins plays a key role in their further development. In this review, currently reported researches on the synthetic chemistry, pharmacological activities and structural modification of renieramycins are summarized, which will benefit future drug development and innovation.

Study on the feasibility of using monolithic catalyst in the in-situ catalytic biomass pyrolysis for syngas production

In-situ catalytic biomass pyrolysis for syngas production is a competitive technology for the recovery of energy in biomass. However, in conventional in-situ catalytic pyrolysis process, the mode of catalyst introduction makes it difficult to separate the catalyst from the char after pyrolysis, resulting in difficulty in catalyst recycling. We considered that the use of monolithic catalyst which has larger size than the biomass feedstock might solve the problem of the separation difficulty between the catalyst and char. In order to verify the feasibility of this strategy, NiO/γ-Al2O3 was respectively supported on ceramic honeycomb, metal foam, and metal wire mesh to produce three monolithic catalysts with different outer surface areas. Their catalytic performance for cattle manure pyrolysis was tested and the result revealed that compared with the granular NiO/γ-Al2O3, using monolithic catalysts with ceramic honeycomb, metal foam, and metal wire mesh carrier respectively increased the gas production by 37%, 33%, and 11%. The use of monolithic catalyst in in-situ catalytic biomass pyrolysis, not only simplified the separation process of catalyst and char, but also enhanced the catalysis performance.

Practice of using the magnetic treatment devices to intensify the processes of primary oil treating

During the primary treatment of oil, gas and water, complications arise associated with the presence of hard water-oil emulsions, which cause an increase in fluid pressure in the gathering systems, pipeline damage, as well as difficulties in gas separation and preliminary water discharge at the preliminary discharge unit (PRU). Additional problems arise during transportation of highly paraffinic oils associated with the crystallization of paraffin in the flow path of the oilfield equipment and on the inner surface of pipes, leading to a drop in the productivity of pipelines. &#x0D; Article discusses the technology of magnetic-reagent treatment of water-oil media, which allows intensifying the processes of primary oil treatment at the facilities of its production. Bench and pilot tests have shown the ability of the magnetic field to accelerate oil demulsification processes, increasing the percentage of separated water during subsequent settling, and to reduce asphalt-resin-paraffin deposits (ARPD) on the inner surface of oil and gas field equipment. &#x0D; Mechanism of the magnetic field effect on water-oil media is described. Effect of treatment on the integrity of the armour shells of oil-water emulsions was studied. Various modes of magnetic treatment have been investigated with evaluation of its effectiveness. It is shown that the best effect is achieved with the combined use of reagents and a magnetic field. Synergistic effect is observed, which consists in increasing their effectiveness. This made it possible to conclude that this method can be applied to reduce the consumption of reagents used in oil production while maintaining the treatment efficiency.

A comparative unit production cost prediction on isomerization by AlCl3 in comparison with HY(30) zeolite for the synthesis of tetrahydro tricyclopentadiene through a two-step process

In our previous study, we verified that a two-step process was superior to the one-pot process for the manufacture of THTCPD, assuming the pilot-scale production aspect of a comparative economic analysis by using an engineering estimation method to predict the unit manufacturing cost. Among the processes of the two-step process, our study was intended to focus on the isomerization to produce the final THTCPD products with outstanding physical properties including a specific gravity, a heat of combustion, a viscosity and a freezing point. Although HY(30) was used as an isomerization catalyst in the previous study, the catalytic activity of HY(30) did not surpass that of AlCl3 in terms of isomerization conversion, possibly due to lower exo-THTCPD selectivity by Bronsted acid sites of HY(30) than that by Lewis acid sites of AlCl3. However, AlCl3 has some drawbacks of the impossibility for the catalyst regeneration during the manufacturing process due to the difficulty of the catalyst separation and recovery after isomerization, which causes environmental problems and biological toxicity issues due to its corrosivity. Therefore, our study concentrated on catalyst regeneration assuming the real production process in a pilot scale using AlCl3 in comparison with HY(30). Then, we investigated whether the isomerization catalyst AlCl3 or HY(30) was more commercially favorable through a comparative unit production cost prediction applying an engineering estimation in this study. In conclusion, the unit production cost for AlCl3 was lower than that for HY(30) with the fresh catalyst. Reversely, unit production costs for HY(30) with increase in catalysts regeneration number (N) were lower than those for AlCl3 due to the drastic decrease in the unit material cost of HY(30) unlikely with that of AlCl3 due to its non-reusability.

A simple and efficient method for separation and purification of troxerutin on the SZ-3 resin

PurposeIn view of the current difficulty of separation of troxerutin, the purpose of the paper is to separate and purify semi-synthetic flavonoid compound troxerutin by macroporous adsorption resin (SZ-3).Design/methodology/approachComparing the adsorption performance and resolution of three different polar resins and choosing a resin to optimize the process parameters such as sample volume, eluent concentration and elution temperature to obtain high-purity troxerutin. After separating and enriching by resin column chromatography, detected the sample by LC-MS analysis.FindingsThis research found that the optimal conditions of the adsorption and desorption were sample volume S = 90 mg/g resin, methanol concentration C = 25%, T = 20 °C. the content of troxerutin increased significantly from 88% to more than 96%. Then confirmed the sample was troxerutin by LC-MS. In addition, the resin could be used for at least 10 cycles in the separation and purification experiments of troxerutin.Originality/valuePurification of troxerutin with new SZ-3 resin for the first time. Under the optimal conditions, the purity and recovery of troxerutin was 96.4% and 39%. In this study, the authors established a purification process of troxerutin successfully that was simple, economical, environment friendly, with high purity and high recovery rate to provide a reference program for changing the status of troxerutin separation difficulties.

Development of a separation method for rare earth elements using LN resin

The lanthanide elements and isotopes are analytes of significant interest for several nuclear-related fields, for example nuclear waste treatment, nuclear forensics, and nuclear safeguards. Chemical separation among these elements is uniquely challenging due to their nearly identical chemical properties. This difficulty in interelement separation can create obstacles for quantitative radiometric analysis, specifically for isotopes without distinct energy emissions easily measured by gamma spectrometry, e.g. 161Tb. This work presents an optimized method for the isolation of individual rare earth elements using LN resin.

HPLC and GC methods development for the analysis of key intermediate for synthesis of dicamba

• An efficient HPLC method was developed for analysis of 2,5-DCP and 2,4-DCP. • The HPLC method showed good linearity, precision and accuracy in the studied range. • The established methods were successfully employed in sample analysis in industry. • The efficient separation and analysis made the production of 2,5-DCP through hydroxylation practically feasible. The microreactor based hydroxylation process of 1,2,4-trichlorobezene for producing 2,5-dichlorphenol, the key intermediate of dicamba, is energy efficient and cost effective. But the 2,5-dicholorphneol is present in a mixed state after production. The reaction mixture contained the main by-product 2,4-dichlorophneol, low-content by-product 3,4-dichlorophneol, and other impurities. The difficulty in separation and analysis limits the application of this process widely. The current work aimed at establishing effective analysis methods by gas chromatography (GC) and high performance liquid chromatography (HPLC). The GC method was not able to separate 2,5-dichlorophenol and 2,4-dichlorophenol completely, but the developed HPLC method worked efficiently. The linear correlation coefficients of 2,5-dichlorophenol and 2,4-dichlorophenol were both higher than 0.999, and the average recovery was 100.33% for 2,5-dichlorophenol and 100.13% for 2,4-dichlorophenol, respectively. The relative standard deviations from precision tests were both less than 1%. The contents of 2,5-dichlorophenol and 2,4-dichlorophenol were determined with external standard method. The HPLC method has the advantages of simple operation, good separation efficiency, high accuracy and precision, and was successfully applied for both qualitative and quantitative analysis of 2,5-dichlorophenol and 2,4-dichlorophenol of the sample solution.