Organic Compounds In Wastewater Research Articles

Emerging organic contaminants and odorous compounds in secondary effluent wastewater: Identification and advanced treatment

This study aims to address organic micropollutants in secondary effluents from municipal wastewater treatment plants (WWTPs) by first identification of micropollutants in different treatment units, and second by evaluating an advanced treatment process for removals of micropollutants. In secondary effluents, 28 types of pharmaceutical and personal care products (PPCPs), 5 types of endocrine disrupting chemicals (EDCs) and 3 types of odorous compounds are detected with total concentrations of 513 ± 57.8 ng/L, 991 ± 36.5 ng/L, 553 ± 48.3 ng/L, respectively. An integrated process consisting of in-situ ozonation, ceramic membrane filtration (CMF) and biological active carbon (BAC) filtration is investigated in a pilot scale (1000 m3/d) for removal of micropollutants in secondary effluents. The total removal efficiencies of PPCPs, EDCs and odorous compounds are 98.5%, 95.4%, and 91.1%, respectively. Removal mechanisms of emerging organic contaminants (EOCs) and odorous compounds are discussed based on their physicochemical properties. The remarkable removal efficiencies of micropollutants by the pilot system is attributed to synergistic effects of combining ozonation, ceramic membrane filtration and BAC filtration. This study provides a cost-effective and robust technology with the capability of treating secondary effluents for reuse applications.

Kinerja Microbial Fuel Cell dengan Variasi Hambatan Eksternal dalam Menghasilkan Energi Listrik dan Menyisihkan Senyawa Organik pada Limbah Cair

wastewater into direct electrical energy. In this study, the applied external resistance in the MFC reactor was optimized to determine its optimum conditions in generating electrical energy and removing organic compounds in wastewater. The MFC reactor's performance was evaluated by cell potential, power density, Coulombic efficiency (CE), and organic removal efficiency. The purpose of measuring these parameters is to determine the MFC reactor's performance in producing electrical energy and removing organic compounds for each experiment variation. Biochemical tests were carried out to choose the type of microorganisms in the anode electrode. This measurement is essential for the optimization of environmental conditions for subsequent experiments. MFC reactor with 100 Ω was selected as an optimum condition since it produced the highest power density and efficiency organic removal. In this condition, the CE value was 57%, slightly lower than the MFC reactor with an external resistance of 50 Ω, 65%. Based on biochemical tests, microorganisms that grow on the anode electrode were closed to the Clostridium (Clostridium sp1 and Clostridium sp2), a type of bacteria that belongs to the class of the exoelectrogen. The results showed that the applied external resistance influenced the performance of the MFC reactor. Thus the selection of the proper external resistance is an essential factor in the MFC reactor's operation.

Synthesis of activated carbon from macadamia nutshells activated by H2SO4 and K2CO3 for methylene blue removal in water

Macadamia nutshell is a new absorbent material for wastewater treatment. This work is a report on the synthesis of activated carbon as an absorbent materials prepared from macadamia nutshells using H2SO4 and K2CO3 as activating agents for methylene blue (MB) removal in water. The results show that MB adsorption capacity reaches its highest at 250.22 mg/g in preparation conditions H2SO4:coke 1:1 after 45 min calcination time when using a H2SO4 agent. The MB adsorption capacity of the absorbent using the K2CO3 agent reaches the highest at 261.52 mg/g in preparation conditions K2CO3:coke 1:1 and 60 min calcination time. Activated carbon prepared from macadamia nutshells activated by H2SO4 agents achieved the best MB removal efficiency of 67.29% in optimal conditions at a dose of 1 g/L with a treatment time of 60 min. The K2CO3agent achieved the best MB removal efficiency of 98.55% in optimal conditions at a dose of 0.5 g/L at a treatment time of 45 min. Macadamia nutshells are a potential new material to prepare the activated carbon in order to remove toxic organic compounds in wastewater.

Impact of differences in speciation of organic compounds in wastewater from large WWTPs on technological parameters, economic efficiency and modelling of chemically assisted primary sedimentation process

The aim of the study was to supplement the information missing in the literature on the influence of organic compounds speciation (percentage of chemical oxygen demand (COD) fractions, readily biodegradable and non–biodegradable dissolved organic matter; slowly biodegradable and non‒biodegradable insoluble organic matter) in wastewater on chemically assisted primary sedimentation process and its potential impact on the energy and economic balance of the plant. The statistical modelling of the chemically assisted primary sedimentation process using artificial neural networks (ANN) was a novelty. It was also important to check the differences resulting from the use of coagulants, polyelectolites and their doses. For both large wastewater treatment plants (>500,000 people equivalent) located in the various regions of the country in Central Europe only ferric chloride had a positive balance. The addition of polyelectrolyte in the Wroclaw wastewater did not affect the chemically assisted primary sedimentation process but in the Bialystok wastewater it strengthened the process effect. In both plants only doses from 10 to 40 mgFe/dm3 are cost-effective. The results indicate that the addition of polyelectrolyte should be taken into account in this application and was correlated with the amount of colloidal COD fractions in wastewater. The developed ANN models reflected well the effectiveness of COD removal in both large WWTP while the sensitivity analysis of individual ANN models showed differences in the variables affecting the calculation process of both models, despite similar values of parameters characterizing wastewater in both wastewater treatment plants.

Akuntansi Manajemen Lingkungan: Metoda Akuntansi Lingkungan Guna Meningkatkan Eko-effisiensi Usaha Dan Mengatasi Krisis Ekologi Studi Pada CV. Andi Offset

Ecological issues have become one of the actual issues today. An anthropocentric mindsetmakes humans position themselves as masters of all creation. This view creates an act ofexploitation of nature which ends up in disaster in the form of environmental pollution.Environmental pollution that occurs today is a symbol of planning and design failure by thecompany. The negative impacts that occurs due to environmental pollution is that the cost ofrepair and control of the environment becomes high, and that there is the potential hiddencost in the income statement of the company. One effort that companies can take to preventand control waste is by managing environmental costs and performing eco-efficiencies thatserve to improve environmental performance.This research was conducted on CV. Andi Offset by using descriptive study approach. Datacollection was performed by means of observation; direct interview with related parties; anddocumentation. The results of this study indicate that the company has been accounting forenvironmental management as a form of compliance with Law No. 32 of 2009 on theenvironment and the Special Region of Yogyakarta Regulation number 7 of 2016 on wastewater quality standards. The use of environmental management accounting to the companyhas added to environmental costs as much as 2% of total production costs. In addition,environmental management accounting also has an effective impact on savings in the form ofwaste paper sales to third parties and improvement of eco-efficiency. However, eco-efficiencyhas not been able to reduce BOD5 levels in organic wastewater compounds; has not beeneffective in the stages of employee empowerment, innovation and enhancement of thecompany's competitive advantage. CV. Andi Offset is expected to make efforts to improveeco-efficiency on BOD5 organic compounds; employee empowerment; innovation andcompetitive advantage.

Application of a Solid Ceramic Membrane for Monitoring Volatile Organic Compounds in Industrial Wastewater.

A large quantity of volatile organic compounds (VOCs) can be released into water environments from oil spills and chemical exposure accidents. A recently developed solid ceramic dosimeter (SCD) could be used for long-term measuring of low VOCs concentrations in water. However, calibration and field testing of these SCDs have thus been far insufficient to apply for VOCs monitoring in a water environment in a chemical industrial area. We conducted laboratory calibration experiments and stability tests of the SCD. The mass accumulation of 14 target VOCs from 2 to 100 μg/L was increased linearly with time in the sampler. The absorption rate of the VOCs was related to Henry’s law constant. The average diffusion coefficient of the 14 VOCs in the SCD wall was 1.02 × 10−9 m2/s. The SCD was utilized in a petrochemical plant complex in South Korea with an industrial wastewater reservoir. After a total of 7 days of deployment, chloroform, ethylbenzene, and toluene were detected by both passive sampling and grab sampling at the same VOC concentrations.

Biotechnology for Gas-to-Liquid (GTL) Wastewater Treatment: A Review

Gas-to-liquid (GTL) technology involves the conversion of natural gas into several liquid hydrocarbon products. The Fischer–Tropsch (F–T) process is the most widely applied approach for GTL, and it is the main source of wastewater in the GTL process. The wastewater is generally characterized by high chemical oxygen demand (COD) and total organic carbon (TOC) content due to the presence of alcohol, ketones and organic acids. The discharge of this highly contaminated wastewater without prior treatment can cause adverse effects on human life and aquatic systems. This review examines aerobic and anaerobic biological treatment methods that have been shown to reduce the concentration of COD and organic compounds in wastewater. Advanced biological treatment methods, such as cell immobilization and application of nanotechnology are also evaluated. The removal of alcohol and volatile fatty acids (VFA) from GTL wastewater can be achieved successfully under anaerobic conditions. However, the combination of anaerobic systems with aerobic biodegradation processes or chemical treatment processes can be a viable technology for the treatment of highly contaminated GTL wastewater with high COD concentration. The ultimate goal is to have treated wastewater that has good enough quality to be reused in the GTL process, which could lead to cost reduction and environmental benefits.

Iron/Sulfur Co-Doped Titanium Dioxide Nanotubes: Optimization of the Photoelectrocatalytic Degradation of Phenol Red under Visible Light

Photoelectrocatalysis is a rapidly developing technology for degrading recalcitrant organic compounds in wastewater due to its ability to overcome electron-hole recombination. Herein, we synthesized Fe/S co-doped TiO2 nanotubes through an in-situ anodization technique. We developed a simple reduced quadratic model based on response surface modeling which can be used to adequately correlate the operating parameters with the photoelectrocatalytic performance of Fe/S-TiNTs in degrading phenol red. Predicted maximum dye degradation of 54.78% was achieved by the generated model using the optimized parameters: initial phenol red concentration = 5.22 mg L-1, applied voltage = 27.4 V, and dopant loading = 2.97 wt.%. Upon validation, experimental maximum phenol degradation of 53.24% was obtained, which agrees well with the predicted value within statistical significance. Overall, our model can be potentially used for process optimization within the design space studied.

A Transport-Phenomena Approach to Model Hydrodynamic Cavitation of Organic Pollutants

Hydrodynamic cavitation (HC) has been extensively studied for the Advanced Oxidation of organic compounds in wastewaters since it physically produces an oxidative environment at ambient conditions. This process is simple and economical since it can be realized through a properly designed restriction in a pipeline, even in retrofit solutions. Several experimental works individuated similar values of the optimal operating conditions, especially with regard to the inlet pressure. Up to now, the available modeling works rely on a single-bubble dynamics (SBD) approach and do not consider the actual process configuration and pollutant transport in proximity to the oxidizing environment. This work describes different experimental results (from this research group and others) and applies a novel mathematical model based on a transport-phenomena approach, able to directly simulate the effect of HC on the pollutant degradation. The novel proposed model is able to reproduce well a large number of experimental data obtained in different conditions, with different apparatus and different molecules, and allows to interconnect both SBD, fluid-dynamics, and physio-chemical variables in order to deeply study the interaction between the transport of pollutants and the reactive environment. This paper includes collection and discussion of several experimental results with the related main process parameters, description of the novel model and validation against the cited experimental results (to explain the effect of the operating pressure), sensitivity analysis, and the performance limit of the HC with the proposed modeling approach.

A 2D Convection-Diffusion Model of Anodic Oxidation of Organic Compounds Mediated by Hydroxyl Radicals Using Porous Reactive Electrochemical Membrane.

In recent years, electrochemical methods utilizing reactive electrochemical membranes (REM) have been considered as a promising technology for efficient degradation and mineralization of organic compounds in natural, industrial and municipal wastewaters. In this paper, we propose a two-dimensional (2D) convection-diffusion-reaction model concerning the transport and reaction of organic species with hydroxyl radicals generated at a TiOx REM operated in flow-through mode. It allows the determination of unknown parameters of the system by treatment of experimental data and predicts the behavior of the electrolysis setup. There is a good agreement in the calculated and experimental degradation rate of a model pollutant at different permeate fluxes and current densities. The model also provides an understanding of the current density distribution over an electrically heterogeneous surface and its effect on the distribution profile of hydroxyl radicals and diluted species. It was shown that the percentage of the removal of paracetamol increases with decreasing the pore radius and/or increasing the porosity. The effect becomes more pronounced as the current density increases. The model highlights how convection, diffusion and reaction limitations have to be taken into consideration for understanding the effectiveness of the process.

Biosurfactant-facilitated biodegradation of hydrophobic organic compounds in hydraulic fracturing flowback wastewater: A dose–effect analysis

Abstract This work investigated the effects of biosurfactant at varied dose on the bioremediation of hydraulic fracturing flowback wastewater (HFFW) and explored the associated mechanism. Initially, a biosurfactant-producing strain Pseudomonas sp. CH1 was isolated from oily sludge. The glycolipid biosurfactant produced by CH1 have a critical micelle concentration (CMC) of 80 mg/L, and showed high stability over a wide range of temperature (0–120 °C), pH (4–12), and salinity (0%–16%, w/v). Addition of sub-CMC dose of biosurfactant to HFFW greatly enhanced the microbial growth and activity, upregulated the expression levels of degradation-related genes, and effectively promoted the biodegradation of n-alkanes (reduction from 272.21 to 56.93 mg/L) and PAHs (reduction from 61.6 to 16.36 μ g/L) in 7 days. The results suggested the feasibility of applying biosurfactant with sub-CMC dose to remediate HFFW and contribute significantly to the optimization of surfactant-facilitated bioremediation strategies.

Smart Bifunctional Sb2 Se3 Nanorods for Integrated Water Purification: Insoluble Liquid Separation and Photoelectrochemical Degradation.

Antimony selenide (Sb2 Se3 ) nanostructures enable bifunctional water purification by a single membrane through i) physical separation of water-insoluble oil and ii) photoelectrocatalytic degradation of water-soluble organic compounds. Sb2 Se3 nanorods with exposed surfaces of {h 0 0} and {h 0 l} planes exhibit superhydrophobicity (water contact angle of ≈159°) owing to extremely low surface energy of those dangling-bond-free van der Waals planes. Based on crystallographic understanding, superhydrophobic Sb2 Se3 nanorods were produced on a mesh-type substrate for utilization as a membrane for physical water/oil separation. Sb2 Se3 exhibited an optimal photocathodic response with p-type electrical conductivity under visible light along the longitudinal crystal direction. This indicated that the nanorods could be used as photoelectrocatalytic material for chemical water purification. A smart membrane with Sb2 Se3 nanostructures was proposed as a candidate for integrated water purification that can simultaneously accomplish water/oil separation and photoelectrocatalytic degradation of organic compounds in wastewater. Linear sweep voltammetry measurements of the Sb2 Se3 -membrane showed cathodic photocurrent generation (up to approximately 10 mA cm-2 at 0 V vs. reversible hydrogen electrode), which was enough to reduce O2 to an oxygen radical (O2 .- ) for degradation of methyl orange. Consequently, solar-driven integrated water purification was demonstrated for the first time by using a single material with a dual function of superhydrophobicity and photoactivity.

Facile preparation of 3D GO with caffeic acid for efficient adsorption of norfloxacin and ketoprofen.

In this paper, a simple and green method was developed to fabricate a three-dimensional (3D) graphene-based material with the assistance of caffeic acid (CA). The prepared 3D graphene displayed fast and high sorption for norfloxacin (NOR) and ketoprofen (KP). Their adsorption equilibrium was achieved within 12 h for NOR and KP, which was attributed to their fast diffusion in the porous structure of the 3D graphene. The maximum adsorbed amount of this adsorbent was 220.99 mg/g for NOR and 125.37 mg/g for KP according to the Langmuir model at pH 6.6, 298 K. In the competitive adsorption of six pharmaceuticals, the organic compounds in the form of cations are preferentially adsorbed on the adsorbent. The co-existing organic compounds in the actual wastewater do not seriously inhibit the adsorption of NOR and KP. This study provides the theoretical basis for the facile and low-cost preparation of high-performance 3D graphene adsorbents. The results of this study demonstrate the potential utility of 3D graphene as a very effective adsorbent for pharmaceuticals removal from contaminated water.

Study on Correlations between Total Organic Carbon and Organic Matter Indexes in Industrial Wastewater from Busan

The introduction of total organic carbon (TOC) as a new organic matter index for industrial wastewater is under consideration. In this study, we investigated characteristics of organic pollutant indexes (TOC, BOD5, CODMn, CODCr) for 11 industrial categories comprising 210 industrial wastewater samples from Busan, Korea. Average organic concentrations for chemical manufacturing and food manufacturing industries are higher than that for other industries. The organic matter oxidation rates of CODCr and CODMn for TOC are 88.7% and 51.9%, respectively. Furthermore, the COD test can be underestimated for organic compounds in wastewater. The correlation between TOC and organic matter indexes was in the order of CODMn (r = 0.970) > CODCr (r = 0.956) > BOD5 (r = 0.812)(p < 0.01). In conclusion, the introduction of TOC, which has higher oxidation rate than COD and high correlation with existing organic matter indexes, is appropriate as an organic index to replace COD. Key Words: Organic matter index, Industrial wastewater, TOC, BOD5, CODMn, CODCr

Advances in carbon-based anode materials for microbial fuel cells

The overuse of resources and the frequent occurrence of environmental problems have necessitated the use of sustainable energy technologies. The microbial fuel cell (MFC) is a kind of green energy-generation technology that metabolizes the organic compounds in wastewater by the catalytic oxidation of microorganisms. This new technology provides the dual advantages of cleaning the environment and generating electricity. As MFCs can potentially convert biodegradable and recyclable wastes into clean energy, they are a promising application prospect in environmental treatment and energy utilization. However, the practical applicability of present-day MFCs is limited by their low power-generation efficiency. Anode electrodes can enrich the power generation and electron transfer of microorganisms, but require high polarization, electronic conductivity, and biological compatibility with the fuel cell. Broadly speaking, the anode electrode affects the performance and operating costs of an MFC. Commonly used carbon-based materials include graphite sheets, carbon cloths, carbon paper, and carbon felt. However, most of these materials are two-dimensional structures providing few attachment sites for microorganisms; other materials have few reactive sites, which limits their electrochemical reactive surface areas and slows the initiation of the MFC. Carbon nanomaterials have been extensively researched for their high electrical conductivity, large specific surface area, high porosity, and low cost. All of these properties are demanded in the anode materials of MFCs. This paper summarized and analyzed methods for improving the biological compatibility of electrodes, increasing the adhesion of electrically-producing microorganisms, and improving the reactive activation sites. To this end, it discussed various types of anode electrodes, electrode structure designs, and electrode material modifications. A mechanism that improved the electricity generation performance was also discussed. Finally, carbon-based electrode materials might provide theoretical guidance for preparing anode materials with high electrochemical activity.

Assessment of Biological and Persistent Organic Compounds in Hospital Wastewater After Advanced Oxidation Process UV/H2O2/O3

This work studies the reduction of biological and organic compounds in hospital wastewaters (HWW) by advanced oxidation process (AOP). The HWW samples were previously treated with an extended aeration process and, thereafter, a post-treatment with AOP based on UV/H2O2/O3 system with a medium pressure mercury lamp was applied. After using the AOP system, the water samples were characterized using chemical oxygen demand (COD), turbidity, color test, coliforms and E. coli test, gas chromatography coupled to mass spectrometry (GC-MS), and UV-Visible absorption spectra. The results showed that 73% of organic compounds were removed in 20 min and the HWW sample was sterilized; nevertheless, 10 persistent organic compounds and 8 by-products formed after AOP UV/H2O2/O3 were observed, some of them are toxic compounds. In this sense, current HWW treatment plants cannot eliminate all contaminants in HWW; therefore, it is necessary to improve current processes by techniques as AOP and create standards to control biological and organic compounds in HWW in Mexico

Efficient degradation of indole by microbial fuel cell based Fe2O3-polyaniline-dopamine hybrid composite modified carbon felt anode

Indole is a high-toxic refractory nitrogen-containing compound that could cause serious harm to the human and ecosystem. It has been a challenge to develop economical and efficient technology for degrading indole. Microbial fuel cell (MFC) has great potential in the removal of organic pollutants utilizing microorganisms as catalysts to degrade organic matter into the nutrients. Herein, a novel anode of Fe2O3-polyaniline-dopamine hybrid composite modified carbon felt (Fe2O3-PDHC/CF) was prepared by electrochemical deposition. The degradation efficiency of indole by the MFC loading Fe2O3-PDHC/CF anode was up to 90.3 % in 120 h operation, while that of the MFC loading CF anode was only 44.0 %. The maximum power density of the MFC loading Fe2O3-PDHC/CF anode was 3184.4 mW·m−2, increasing 113 % compared to the MFC loading CF anode. The superior performances of the MFC with Fe2O3-PDHC surface-modified anode owned to the synergistic effect of high conductive Fe2O3 and admirably biocompatible polyaniline-dopamine. MFC with the Fe2O3-PDHC/CF anode could produce considerable electricity and effectively degrade indole in water, which demonstrated a practical approach for the efficient degradation of refractory organic compounds in wastewater.

Enhanced ibuprofen removal by heterogeneous-Fenton process over Cu/ZrO2 and Fe/ZrO2 catalysts

The aim of this work is to develop new heterogeneous catalysts for the mineralization of Ibuprofen, a pharmaceutical compound commonly found in wastewaters, using a Fenton like process. Copper and Iron catalysts supported over zirconia, eventually doped with strontium were developed. Structural and morphological properties of the materials were investigated by conventional techniques and Fenton-like reactions were carried out in a batch system. Copper/iron-doped zirconia samples exhibited a promising activity in terms of Ibuprofen degradation and mineralization. The best catalyst, copper supported over zirconia, achieved an almost complete degradation of ibuprofen (98 %) with 50 % of mineralization. Optimization of the reaction variables (oxidant dose, pH, catalyst loading and temperature) led to increase process efficiency. Moreover, these catalysts do not produce toxic metabolites which is important when considering the degradation of water pollutants. The present study highlights the potential of copper/iron supported catalysts for the removal of organic compounds in wastewaters via heterogeneous Fenton-like process.

Modeling of azo dyes adsorption on magnetic NiFe2O4/RGO nanocomposite using response surface methodology.

Azo group dyes are the largest group of synthetics dyes that widely used in industries, especially in textile industry. The presence of these organic compounds in wastewaters and their discharge into environment without efficient treatment may cause adverse effect on human, living and aquatic environment. The purpose of this study was to optimize the adsorption of azo dye of Direct Red 81 (anionic dye) and Basic Blue 41 (cationic dye) from aqueous solution onto magnetic NiFe2O4/RGO nanocomposite. In this study the response surface methodology (RSM) based on the central composite design (CCD), was used to optimization and modeling of adsorption process DR81 and BB41 dye on NiFe2O4/RGO. in order to investigating the effect of the operating parameters on the adsorption efficiency DR81 and BB41, four influential factors were chosen that includes of pH (3-9), contact time (5-25min), adsorbent amount (0.02-0.05g) and initial dye concentration (40-200mg/L). A total of 30 experiments were performed for each dye in this study. The concentration of dye in solution was measured by spectrophotometer. The structure of synthesized adsorbent was investigated using Scanning Electron Microscope (SEM), X-ray diffraction (XRD), Fourier transform irradiation (FTIR), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). Analysis of variance (ANOVA) showed that regression model for both dye adsorption with value of P value <0.001 is significant statistically. The correlation coefficient (R2) for DR81 (R2 = 0.9968) and BB41 (R2 = 0.9948) indicated which there is a good agreement between predicted values and the results of the experiments and the model also well predict the adsorption efficiency. Furthermore, the factors of pH, dye concentration and adsorbent dose, have the greatest effect on adsorption, respectively, while contact time have the lowest effect on adsorption of both dyes. The adsorption behavior of the DR81 and BB41 onto NiFe2O4/RGO was best described by the Langmuir and Freundlich isotherm, respectively. The optimum conditions for maximum removal of DR81 (96.41%) was found to be at pH3, contact time 19.68min, adsorbent dose 0.02g and initial dye concentration 40mg/L. However, the optimum conditions for maximum removal of BB41 (97.87%) was found to be at pH9 contact time 18.16min, adsorbent dose 0.02g and initial dye concentration 40mg/L. The present study shows that magnetic NiFe2O4/RGO nanocomposite have much potential as a powerful adsorbent for the rapid adsorption of anionic (DR81) and cationic dyes (BB41) from aqueous solution.

Identification of unknowns in industrial wastewater using offline 2D chromatography and non-target screening

Industrial wastewater is characterised by a complex composition of trace organic compounds (TrOC) in a difficult matrix. The identification of unknown pollutants is of high interest. On the one hand to ensure protection of the environment by elucidating contaminations and on the other hand to protect the biological treatment step in the wastewater treatment plant (WWTP). Due to the high variability of the matrix, the identification of compounds of interest is very time consuming and often unsuccessful. To overcome this limitation, a prioritisation method was developed to identify so called ‘known unknowns’, i.e. compounds frequently detected but not identified, as prioritised compounds in industrial wastewater. The method based on an offline two-dimensional (offline 2D) liquid chromatography (LC) approach with ultra violet (UV) detection in the first and high-resolution mass spectrometry (HRMS) in the second dimension. As a proof of concept, an identification process of one ‘known unknown’ is described. The compound was identified as a dichlorodinitrophenol isomer by retention time in two dimensions, UV spectrum, exact mass, mass fragmentation and 1H- NMR. As prioritisation method, the offline 2D LC in combination with non-target analysis provides a powerful workflow to determine tentative structures of unknown organic compounds in industrial wastewater.