Industrial Effluent Streams Research Articles

Monitoring WAD cyanide concentration in river waters with a glassy carbon electrode modified with 9,10‐Phenanthroquinone

AbstractHeavy metal‐containing industrial effluent streams from electroplating and metalworking industries represent a major environmental issue. They contain metal cyanide complexes ([Ni(CN)4]2− and [Cu(CN)3]2−) referred to as weak acid dissociable cyanide (CN‐WAD), which require continuous in situ monitoring. In this scenario, a glassy carbon (GC) electrode superficially decorated with 9,10‐phenanthroquinone (FNQ) is manufactured and employed for the simultaneous electrochemical monitoring of cyanide WAD complexes. The interaction between GC and FNQ was characterized by Raman and electrochemical impedance spectroscopies, cyclic voltammetry, and chronocoulometry. The electrochemical evaluation was conducted by differential pulse voltammetry (DPV) and CV. The GC/FNQ electrochemical sensor simultaneously detected cyanide complexes with an average linear range of 9–93 μmol L−1, and a detection limit of 0.15±0.04 μmol L−1 and 1.2±0.6 μmol L−1 for [Ni(CN)4]2− and [Cu(CN)3]2−, respectively. The sensor demonstrated remarkable selectivity in the presence of multiple interfering species with a percentage variation range of 89.2–109.4 %. Moreover, a computational DFT study provided valuable insights into the electrode/electrolyte interface. Finally, the developed sensor was applied for the electrochemical detection of WAD cyanide in river water samples.

Effect of the Standardized ZnO/ZnO-GO Filter Element Substrate driven Advanced Oxidation Process on Textile Industry Effluent Stream: Detailed Analysis of Photocatalytic Degradation Kinetics.

A simple process of synthesizing coated filter element substrates (FES) containing zinc oxide (ZnO) nanorods and ZnO graphene-oxide nanocomposite for a pilot-scale industrial dye-effluent treatment plant is proposed. This work reports a detailed analysis of the photocatalysis mechanism on real industrial effluent streams containing a mixture of dyes. The analysis is very relevant for conducting advanced oxidation process-assisted effluent remediation at a field-level treatment operation. Estimation of the dye concentration shows nearly complete (≥98%) degradation from an initial dye sample concentration. A detailed study for the analysis of the initial reactive dyes and their degradation products was performed for quantification and identification of the degradation products through various spectral techniques. A design of the remediation mechanism through degradation pathways is proposed for characterizing the organic compounds in the degraded dye products. A regeneration and reusability study was performed on the FES presenting the durability of the FES-designed synthesis process originally for 11 cycles and regenerated FES for six cycles for achieving a threshold of 60% degradation efficiency. The experimental results demonstrate the efficacy of FES through the designed immobilized approach for the complete remediation of textile dye effluents for a 4 h treatment plant process and the consistent operability of the FES for the combined dye wastewater treatment operations.

Optimal Operational Profiles in an Electrodialysis Unit for Ion Recovery

Electrodialysis is an efficient process for the cleaning of industrial water effluent streams from toxic ionic substances with the simultaneous recovery of valuable ions for reuse. Energy consumption and waste recovery are the two key goals of the process. A dynamic optimisation program aims to determine the optimal operating conditions in terms of applied voltage and effluent flow rate in a batch operating scheme. A model is developed that accounts for the ion transfer through the ion selective membranes and the dynamics of the system. A combination of three objective functions targeting the minimisation of the overall batch process time, the minimisation of the electrical energy consumption required for the ion transfer, and the maximisation of the overall degree of separation is investigated. The manipulated variables applied voltage and feed stream flow rate are considered as piecewise constant during each time interval, spanning the duration of the entire batch. The dynamic optimisation problem is solved through standard non-linear programming techniques which calculate the optimal batch duration and condition profiles for the system. A multi-objective analysis is presented for various combinations of weight values for the joint objective function through the development of the Pareto optimal front. The current approach has been implemented in the removal and recovery of sulfuric anions from an aqueous solution and resulted in the achievement of a high degree of separation in a shorter period at a much lower energy consumption.

Harnessing Photoelectrochemistry for Resource Recovery from Wastewater Nitrates

Nitrates are present in industrial effluent streams from fertilizer production, iron/steel production, coal mining, and municipal wastewater streams. Typically, nitrates are eliminated from wastewater through biological nitrification-denitrification treatment processes, but these are energy and carbon intensive, are not applicable for all waste streams and have not prioritized nitrogen recovery. We propose a photoelectrochemical device is proposed to transform wastewater nitrates to ammonia, nitrous oxide, and dinitrogen, coupled with water oxidation. Numerical models are developed to quantify process efficiencies and nitrogen-removal as a function of light absorber band gaps, electrocatalytic kinetic parameters, competing oxygen reduction and hydrogen evolution reactions, and the reacting nitrate species concentrations. A device-scale model was also developed to capture the coupled effects of light absorption, species transport and reaction kinetics. With a single light-absorber and state-of-the-art catalysts, optimal solar-to-chemical efficiencies of 7% and 11% and nitrogen-removal rates of 251.3 and 451.6 gN m-2 day-1 are predicted for the formation of ammonia and nitrous oxide respectively. Theoretically predicted peak nitrogen removal rates and specific energy intensities are competitive with reported estimates for bioelectrochemical and Sharon-Anammox processes that recover ammonia from waste streams. This result, together with the added benefit of harnessing sunlight to effect the nitrate transformation to value-added products, indicates promise in the proposed photoelectrochemical pathway for wastewater nitrogen removal coupled with resource recovery. Figure 1

Device-Scale Modeling of a Photoelectrochemical Wastewater Nitrate Treatment Device: Effects of Competing Reactions and Effluent Stream Composition

Nitrate contaminants dominate low-level nuclear wastes and agricultural runoff streams; nitrates and ammonium are present in industrial effluent streams from fertilizer production1, iron/steel making and finishing2,3, coal mining4,5, and municipal wastewater streams6. Most conventional wastewater treatment plants use the biological nitrification-denitrification treatment processes in which microbes consume and metabolize the dissolved contaminants to eliminate nitrates present in wastewater7,8. However, biological processes are energy intensive and are not effective in effluent streams that harbor conditions unsuitable for microbial growth9–11. We previously proposed a solar-powered photoelectrochemical device to treat wastewater nitrates12 and determined that reducing wastewater nitrates to ammonia and nitrous oxide facilitated an improved scope for energy recovery as compared to the traditional electrochemical denitrification processes that convert nitrates to dinitrogen (Figure, left). In this study, a device-scale model transport and kinetic model was developed to specifically investigate the influences of competing redox reactions and the effluent stream composition on the overall performance of this device. Competing reactions of interest were hydrogen evolution reaction, hydrogen oxidation reaction, oxygen reduction reaction, and reactions resulting from other ions present in the considered waste stream (Figure, right). The different effluent stream compositions considered were alkaline waste solutions from nuclear processes and ion-exchange brines from ion-exchange water treatment applications. The developed model predicts various performance metrics including the rates of product formation, solar energy conversion efficiency, the time required to reduce the initial concentration of nitrates to 0.1 mM, which is on the order of magnitude of what the US Environmental Protection Agency has deemed safe for human consumption, and faradaic efficiencies to quantify the effects of competing reactions. Model results demonstrate that the hydrogen evolution reaction competes with the nitrate reduction reaction at the cathode. However, the extent of competition was dependent on the cathode electrocatalytic parameters, the initial waste stream composition, and the light-absorber bandgap that dictated the operating potential. It was also found that the oxygen reduction reaction and the hydrogen oxidation reaction have negligible effects on the solar energy conversion efficiency of the device.

Sustainable Wastewater Treatment via Dye–Surfactant Interaction: A Critical Review

Dye containing industrial effluent streams are cause of major environmental concerns, especially those which are not easily biodegradable. Many techniques have been developed to remove dyes from th...

Analysis of Evaporation Data from an Enclosed Pond Ventilated by Solar Chimney

Water removal from industrial effluent streams, salt cultivation farms, biodiesel conversion process from microalgae, and food drying by using pond evaporation with a higher rate of mass flux can be considered as an economical and energy saving scheme. The objective of this study is to utilize a method of enhancing the pond natural evaporation rate to improve the sustainability of industrial operations. In this study, canopied ventilation technology was employed to enhance the pond evaporation. This technology caused the natural draft enhancement by installing a wire mesh on the chimney. The unit consists of a solar irradiated solid wall chimney installed on the evaporation pan as a means to increase the evaporation rate of existing water body. Experiments were conducted in square pan at the same size as class-A pan in three configurations. The experimental result showed that the evaporation flux from configuration YY (Solar chimney with wire mesh) averaged at 13 per cent more than configuration NN (Open Pond) and at 20 per cent more than configuration YN(Solar chimney without wire mesh). Counter to intuition, for configuration YN the evaporation averaged at 6 per cent lower than the evaporation from the open pond configuration. The pan evaporation flux was found to be predicted satisfactorily by the Rayner[5] evaporation model showing it is able to aggregate reasonably the effect of changing characteristics of the three configurations in terms of net radiation, vapor pressure deficit and natural ventilation draft.

Hollow fiber gas membrane-based removal and recovery of ammonia from water in three different scales and types of modules

Ammonia present in many industrial process streams and effluent streams is beginning to be recovered by means of microporous hydrophobic hollow fiber-based membrane contactor devices with gas-filled pores; the process is often characterized as supported gas membrane (SGM) process. Ammonium sulfate is usually obtained in a sulfuric acid stream on the other side of the membrane. It is useful to develop a quantitative basis for the extent of ammonia removal in such devices. Unlike deoxygenation of aqueous streams in such devices, membrane resistance is quite important for ammonia transport. Ammonia transport modeling in such devices is hampered by the complexity of feed liquid flow in the shell side of commercially used devices and lack of information on membrane resistance where membrane tortuosity introduces considerable uncertainty. The approach adopted here involves studying ammonia transport with the feed solution flowing through the hollow fiber bore where the fluid mechanics is simpler than shell-side flows. Comparison of model-based predictions of overall mass transfer coefficient (ko) with experimentally observed values allows estimation of the membrane mass transfer coefficient (km). One can use such estimates of km to model the observed ammonia transport in small crossflow devices and develop an empirical guidance of the dependences of the shell side mass transfer correlations. Guided by such information and deoxygenation SGM literature, a model was developed for large modules used for ammonia recovery via SGM. Model predictions of performances of the large modules are likely to be useful for various process considerations including the effect of temperature and feed flow rate variations on ammonia removal.

A review on emulsion liquid membrane (ELM) for the treatment of various industrial effluent streams

The excessive release of toxic metal ions by the several industrial effluent streams into the environment has imposed a serious threat to the ecological system. Therefore, the removal of these toxic metal ions from the wastewater of various industrial effluent streams has received a considerable amount of interest and also currently becoming an imperative area of research. Since last few decades, ELM based separation processes have been become an attractive and efficient way for the removal of toxic metal ions, organic and inorganic acids, and industrial pollutants of the various aqueous waste effluent streams. ELM is an emerging alternative technique to the conventional solvent extraction processes with an additive advantage of low solvent inventory and energy requirements. Moreover, it also preconcentrates the solute by performing both extraction and stripping operations simultaneously in a single unit. The main aim of this review paper is to elucidate the comprehensive review on the ELM (its pertinent properties/characteristics), its membrane phase compositions, its stability, and its process parameters respectively and also to delineate the applications of this technique for the removal of various low concentrated solutes.

Extraction of hexavalent chromium by environmentally benign green emulsion liquid membrane using tridodecyamine as an extractant

In this present investigation, the potentiality of rice bran oil (RBO) and tridodecylamine (TDDA) to be incorporated as the key constituents in the formulation of new environmentally benign green emulsion liquid membrane (GELM) to extract hexavalent chromium (Cr(VI)) from aqueous feed phase was explored. The pertinent constituents of GELM were RBO (70%, v/v) and hexane (30%, v/v) as green and organic diluent, respectively; TDDA (0.75 (%, v/v) of diluent solution) as carrier; emulsifying agent (span 80: 1.75 (%v/v) of diluent solution); and NaOH as internal reagent. The investigation of optimum process conditions for various parameters has resulted in 0.45pH of aqueous solution, 0.25 [M] internal phase concentration, 2:1 (v/v) treat ratio, 0.40 (v/v) phase ratio, 550 (rpm) agitation speed, 25 (min) extraction time, and 30±2 (°C) feed phase temperature. The highest achievable extraction efficiency (η, %) and dynamic stability (min) of GELM have been obtained as 97±2% and 150±2min, respectively under these optimum process conditions. The present finding has revealed that RBO as a green diluent has huge capability to be further utilized for the extraction of Cr (VI) from various industrial effluent streams.

Removal of copper ions from dilute synthetic solution using staple ion exchange fibres: Dynamic studies

Heavy metals such as copper (Cu2+) ions can have detrimental effects on the environment and human health if present at high concentrations in industrial effluent streams. Unfortunately, conventional techniques are ineffective in removing these metals from effluent streams. Therefore, it is imperative that new methods with exceptional qualities are found. This paper presents the removal of Cu2+ ions using ion exchange fibres (IEFs). The study focused on the effect of bed packing density and flow rate on loading and elution of Cu2+ ions. The optimal bed packing density, superficial velocity and residence time which corresponded to the highest removal of Cu2+ ions were 0.16g/cm3, 5.2cm/min and 2min, respectively. Overall, metal removal increased with a decrease in packing density and flow rate. All the loaded Cu2+ ions were completely eluted in all the bed packing densities and flow rate studied. Nevertheless, the elution rate of Cu2+ ions was not affected by bed packing density, but it increased with an increase in acid flow rate. Amongst the fitted empirical models, the Yoon-Nelson model best described the adsorption of Cu2+ ions from synthetic wastewater onto the selected IEFs .

Synergistic Degradation of 4-Nitrophenol Using Hydrodynamic Cavitation in Combination with Hydrogen Peroxide

p-Nitrophenol (PNP), a widely utilized intermediate, is a persistent pollutant present in industrial effluent streams. The inherent toxicity of PNP necessitates its treatment before releasing it in the environment. The conventional approach pertaining to degradation of PNP is based on chemical and biological methods for decomposition. Alternatively, Hydrodynamic Cavitation (HC) is emerging as a promising technology for waste water treatment. This study investigates HC as an alternative technology to degrade PNP and subsequently enhance efficiency by varying involved parameters. The HC-H2O2 system is reported to exhibit synergism for pollutant oxidation, the applicability of which is also investigated for degrading PNP. A PNP solution of fixed concentration was subjected to HC using a circular Venturi. Degradation was studied by varying time, pressure, pH and H2O2 concentration. Decompostion of p- Nitrophenol was quantified by UV-Visible Spectroscopy at 405nm. Degradation of PNP was observed to be directly proportional to time at constant pressure and an initial increase in pressure led to higher degradation. However, on achieving a peak decomposition level, the extent of decomposition declined with further increase in pressure. Experiments done at acidic pH resulted in over two times the decomposition than those done at basic pH. The PNP- H2O2 system exhibited 91% more degradation than the sum of degradations affected by PNP and H2O2 individually. Moreover, subjecting PNP:H2O2 in a molar ratio of 1:5 to HC resulted in near-complete (>95%) degradation. This study proposes variations of parameters for optimum decomposition of PNP using HC and explores the HC-H2O2 system as a promising alternative for the degradation PNP.

Application of Nanomaterials for the Removal of Pollutants from Effluent Streams

Rapid industrialization with the increase in the population leads to the water crisis. The number of industries using heavy metals such as copper, chromium, nickel, zinc, etc. in their process is also leaving behind the effluent containing a large amount of heavy metals which discharged directly to the water bodies. There are constraints set by the regulatory bodies of government on the industries to maintain an upper level discharge limit for each of the metal ion. There are various methods available for the removal of metal ions which are selected according to the requirement. Adsorption is one of the optimal solutions for the removal of metal ions from industrial effluent streams. It is helpful in reducing the operational cost and size of equipment along with the increase recovery of metal ions. Adsorption is a surface phenomenon so the foremost property required for a perfect adsorbent is the higher surface area. Nanoparticles are now being preferred to be used as an adsorbent due to their large surface area which is a very important characteristic for a desired adsorbent. Development of nanoparticles has been the subject of enormous interest since the past decade. They have incredible adsorption properties due to the presence of high-energy adsorption sites and they also have excellent binding energies or interaction potentials for physisorption than traditional adsorbents. This study summarized the use of nanomaterial for the removal of metal ions from wastewater streams. It also highlights the various types of nanomaterials, their fabrication method and characteristics. The mechanism of metal adsorption onto various nanomaterials is also described in this study.

Fe-TAML/hydrogen peroxide degradation of concentrated solutions of the commercial azo dye tartrazine

Here we describe a catalytic oxidation process for decomposing concentrated dye solutions, as a model for the treatment of concentrated industrial effluent streams. The prototype Fe-TAML/H2O2 oxidizing system rapidly and extensively degrades the recalcitrant azo dye, tartrazine, in water at ambient temperatures and at dye concentrations that are industrially important. Nearly complete dye removal can be obtained with performance-optimized dosing and pH control. At higher, but still remarkably low catalyst and oxidant concentrations, the dye is removed to below detection limits. 3D surface plots reveal that optimum decolorization at high dye concentration (16.5 g L−1, 30.9 mM) requires 50 times less catalyst and 5 times less oxidant per substrate than at low dye concentration (16.5 mg L−1, 30.9 μM), demonstrating a clear process benefit of higher substrate concentrations. The Fe-TAML/H2O2 system generates environmentally benign and/or biodegradable products from tartrazine: small organic acids, 4-phenolsulfonic acid, and a small amount of 4-nitrobenzenesulfonic acid. The acute toxicity of the Fe-TAML/H2O2/tartrazine reaction mixture toward luminescent bacteria is approximately half that of tartrazine as determined by the Microtox® assay. The results suggest a potential utility of the Fe-TAML/H2O2 technology for treating wastewaters containing high substrate concentrations from the dyeing industry in a straightforward manner to ameliorate environmental impacts, and because of the degradation resistance of tartrazine, that this potential utility might extend to other industries.

Removal of toxic metal Cr(VI) from aqueous solutions using sawdust as adsorbent: Equilibrium, kinetics and regeneration studies

In the present study, a low-cost adsorbent is developed from the naturally and abundantly available sawdust which is biodegradable. The removal capacity of Cr(VI) from aqueous solutions and from the synthetically prepared industrial effluent of electroplating and tannery industries is obtained. The batch experiments are carried out to investigate the effect of the significant process parameters such as initial pH, change in pH during adsorption, contact time, adsorbent amount, and the initial Cr(VI) concentration. The maximum adsorption of Cr(VI) on sawdust is obtained at an initial pH value of 1. The value of pH increases with increase in contact time and initial Cr(VI) concentration. The equilibrium data for the adsorption of Cr(VI) on sawdust is tested with various adsorption isotherm models such as Langmuir, Freundlich, Redlich–Peterson, Koble–Corrigan, Tempkin, Dubinin–Radushkevich and Generalized equation. The Langmuir isotherm model is found to be the most suitable one for the Cr(VI) adsorption using sawdust and the maximum adsorption capacity obtained is 41.5 mg g −1 at a pH value of 1. The adsorption process follows the second-order kinetics and the corresponding rate constants are obtained. Desorption of Cr(VI) from sawdust using acid and base treatment exhibited a higher desorption efficiency by more than 95%. A feasible solution is proposed, for the disposal of the contaminant (acid and base solutions) containing high concentration of Cr(VI) obtained during the desorption process. The interference of other ions which are generally present in the electroplating and tannery industrial effluent streams on the Cr(VI) removal is investigated.

Metals Removal, Recovery, Leaching, and Disposal—Many Ways, One Goal!

Mankind’s association with metals can be traced back to 6000 B.C. The Mesopotamians, Egyptians, Greeks, and Romans would never have thought that metals in trace amounts could pollute our ecosystems, namely, water, air, and soil. Moreover, growing industrialization and urbanization have put pressure on government agencies and lawmakers to make stricter environmental policies. The introduction of new stringent environmental regulations means that industries are now being forced to comply with the strict discharge consent levels for both solid wastes and industrial effluent streams. One of the main causes of industrial pollution is the discharge of effluents containing heavy metals, which have adverse environmental and health impacts. Besides having health and environmental effects, heavy metals are nonrenewable resources, and therefore effective recovery of heavy metals is as important as their removal from waste streams. The management of metals in wastes is a significant current topic and debatable issue. The actual and apparent risks associated with metals and their persistence in the environment and disposal pervade every aspect of the metals debate. The varied understandings of risk influence political, regulatory, economic, and social decisions, which in turn influence technical decisions. Metal waste issues are even more complex when coordination is required among programs of various countries to achieve individual management and disposal goals and to set universal regulatory norms. The resolution of this debate is complex, with technical and nontechnical issues of arguably equal merit. This special issue on metal removal and recovery seeks to provide a forum for discussion of the issues associated with metals removal from soils and residues, wastewater and wastewater sludge, leaching, recovery, disposal, and value-addition decisions. Releases of metals and metal compounds to the environment have long been a concern for many regulatory and nonregulatory programs of the U.S. Environmental Protection Agency USEPA due to risks they can pose to human and ecological health. The USEPA conducts a wide range of actions to assess and manage these risks. In June 2002, the USEPA Metals Assessment Work-

Toxicity Evaluation of the Process Effluent Streams of a Petrochemical Industry

The physico-chemical characteristics and the acute toxicity of several wastewater streams, generated in the industrial production of synthetic rubber, were determined. The acute toxicity was evaluated in bioassays using different organisms: Danio rerio (fish), Lactuca sativa (lettuce) and Brachionus calyciflorus (rotifer). The removal of toxicity attained in the industrial wastewater treatment plant was also determined upstream and downstream of the activated sludge process. The results obtained indicate that the critical streams in terms of acute toxicity are the effluents from the liquid polymer unit and the spent caustic butadiene washing stage. The biological treatment was able to partially remove the toxicity of the industrial wastewater. However, a residual toxicity level persisted in the biotreated wastewater. The results obtained with Lactuca sativa showed a high degree of reproducibility, using root length or germination index as evaluation parameters. The effect of volatile pollutants on the toxicity results obtained with lettuce seeds was assessed, using ethanol as a model compound. Modifications on the assay procedure were proposed. A strong correlation between the toxic responses of Lactuca sativa and Danio rerio was observed for most industrial effluent streams.

Desalination and water recovery: control of membrane fouling

Ultrafiltration (UF), Nanofiltration (NF) and Reverse Osmosis (RO) technologies are widely used for the production of safe drinking water, and for the recovery of reusable water from various industrial effluent streams. The most commonly encountered phenomenon in these processes, especially in water recovery application, is membrane fouling, and control of membrane fouling is regarded as a significant challenge. Membranes with charged and hydrophilic surfaces are reported to be less susceptible to fouling and often reversible. UF/RO membranes containing negatively charged and/or neutral hydrophilic functional groups on the surface were prepared by surface modification of suitable membranes. The surface modified membranes exhibited separations of 68%–85% for Na2SO4, 19%–31% for MgSO4, 10%–26% for NaCl and 2%–12% for CaCl2 with water permeation rates of 9–50 l/m²-h at the operating pressure of 4 kg/cm². The UF membranes were tested for water recovery from reactive dye effluents containing solutes with molecular sizes in the range of 600–1000 Da along with inorganic solutes. Surface-modified RO membranes were utilised for desalination of brackish water.

Ammonium Binding Resins: Polymer-tethered Tetraphenylborate

A novel approach to the problem of removing (organo)ammonium ions from industrial effluent and agricultural wastewater streams is proposed. Capitalizing on the insolubility of (organo)ammonium tetraphenylborate in water, we have designed, synthesized, and tested a polymer-tethered system that eliminates the ammonium ion from aqueous solution. Furthermore, the binding can be controllably reversed, thereby regenerating the material by deprotonating the ammonium ion in strong base, without significantly reducing the binding properties of the matrix. This work thus presents the synthesis and characterization of a polymeric system bearing anionic tetraphenylborate groups that reversibly sequester (organo)ammonium cations.

A novel application for Neurospora crassa: Progress from batch culture to a membrane bioreactor for the bioremediation of phenols

The capacity of a Neurospora crassa fungal system to produce oxidative enzymes, and their application in the biodegradation of phenolic compounds, was demonstrated in static and shaken non-immobilized batch cultures, and by capillary membrane-immobilized biofilms. Extracellular laccase activity was produced at 10–12 U/mL (800 U/g wet mass) in static flask cultures, and 1.5 U/mL (130 U/g wet mass) in shaken batch cultures, respectively, over 8–15 days. Polyphenol oxidase was shown to be produced as an intracellular enzyme, at levels of 374 U/g wet mass. The production of laccase in a capillary membrane bioreactor was sustained at a level of 10 U/mL of permeate (1080 U/g wet biomass), typically over 30–40 days. Two phenolic substrates, phenol and p-cresol, both common components of industrial effluent streams, were chosen as model pollutants for bioremediation studies using the N.crassa enzyme system. In flask cultures, 18 mg p-cresol and 23 mg phenol respectively were removed from 5 mM solutions/g wet biomass, over a 6 day period. Over the same time period, immobilized cultures were found to convert 10 mg p-cresol or 8 mg phenol/g biomass. The immobilized biomass in a continuous reactor was found to have the capacity to sustain this removal efficiency continuously for a 4-month period, whereas the batch liquid culture systems remained active for approximately 8–15 days, after which cultures were no longer viable. This is the first demonstration of the use of immobilized N.crassa biofilms and their continuous application for bioremediation of phenols.