Biosorptive removal of Pb(II) and Cu(II) from wastewater using activated carbon from cassava peels

The ability of activated carbon from cassava peels to remove heavy metals like Cu(II) and Pb(II) from hospital wastewater was investigated. The study showed that a pH of 8 was the best for the sorption of both metal ions onto the biosorbent. The time-dependent experiments for the metal ions showed that the binding of the metal ions to the biomass was rapid and occurred within 20–120 min. Sorption efficiency increased with a rise in adsorbent dosage. It increased from 12 to 73 % for Pb(II) and 26 to 79 % for Cu(II) when the adsorbent dose increased from 2 to 12 g. An increase in temperature led to an increase in sorption for both metal ions. The Langmuir model showed that the biomass has a higher sorption capacity for Cu(II) than Pb(II), with q _m = 5.80 mg g^?1 for Pb(II) and 8.00 mg g^?1 for Cu(II). The Freundlich isotherm K _f was 1.4 for Pb(II) and 1.8 for Cu(II), indicating a preferential sorption of Cu(II) onto the biosorbent. Adsorption capacity was found to decrease with an increase in particle sizes. Sorption occurred by physical mechanisms and was mainly controlled by intraparticle diffusion.     

Sorption of strontium on bentonite

Sorption of Sr on bentonite was studied using the batch technique. Distribution coefficients (K_d) were determined as a function of contact time, pH, sorbent and sorbate concentration and temperature. The data were interpreted in terms of Freundlich, Langmuir and Dubinin-Radushkevich isotherms. Thermodynamic parameters for the sorption system were determined at three different temperatures. The positive value of the heat of sorption, ΔH° = 30.62 kJ/mol at 298 K, shows that the sorption of strontium on bentonite is endothermic. The negative value of the free energy of sorption, ΔG° = −10.69 kJ/mol at 298 K, shows the spontaneity of the reaction. ΔG° becomes more negative with increasing temperature, which shows that the sorption process is more favorable at higher temperatures. The mean free energy for sorption, E 9 kJ/mol, suggests that ion exchange is the predominant mode of sorption in the Sr concentration range studied, i.e. 0.01 – 0.3 mol/dm³. The presence of complementary cations depresses the sorption of strontium on bentonite in the order Ca²⁺>Mg²⁺>K⁺>Na⁺. Some organic complexing agents and natural ligands also affect the sorption of strontium. The desorption studies with ground water at low strontium loadings on bentonite show that about 90% of Sr is irreversibly sorbed on the bentonite.     

Effect of Sediment Humic Substances on Sorption of Selected Endocrine Disruptors

Characterizing sorption processes is essential to understand the environmental distribution and toxicity potential of endocrine disruptors in terrestrial and aquatic systems. The sorption behaviors of three endocrine disruptors (bisphenol A (BPA), 17β-estradiol (E2), and 17α-ethynylestradiol (EE2)) on sediments were investigated using batch techniques. Samples were taken from some representative reaches in several major Chinese rivers. More attention has been paid to the effect of sediment organic components on the sorption of BPA, E2, and EE2. The results show that the sediment organic carbon-normalized partition coefficients (K _oc (sed)) for three endocrine disruptors are in the order of EE2 > E2 > BPA, which corresponds to the octanol-water partitioning coefficients (logK _ow) of the compounds. Moreover, the K _oc values for humic substances (K _oc (hs)) are comparable with the K _oc (sed) values and highly dependent on the physico-chemical properties of humic substances in sediments. The UV absorptivity at 272 nm (A ₂₇₂), which suggests the abundance of aromatic rings in humic substance structure, correlates well with the K _oc (hs) values. In addition, the infrared spectra of the humic substances extracted from sediments show four strong bands centered at 3,400 cm⁻¹, 1,625 cm⁻¹, 1,390 cm⁻¹, and 1,025 cm⁻¹. The K _oc (hs) values have a positive linear relation with the peak area ratio for peak at 1,025 cm⁻¹ and a negative linear relation with the peak area ratio between peaks at 1,625 cm⁻¹ and 1,025 cm⁻¹. Hence, the hydrogen bonds play a critical role to the sorption of selected endocrine disruptors.     

Sensitivity of Water Quality Model Results for the Dutch Coastal Zone to the Distribution Coefficient of Cadmium

Results of a water quality model of the Dutch coastal zone appeared to be highly sensitive for the distribution coefficient particulate/dissolved (K_d) of cadmium.Field data of the Dutch coastal zone were used to calculate the annual and seasonal trend in the distribution coefficient of cadmium over the years 1983–88. A strong seasonal and spatial gradient in the distribution coefficient was found with relatively high values in summer and lower values in winter (K_d=3.0–7.0 log l/kg). Near the coast (2 km) the K_d was lower than more offshore (70 km from the coast). In addition, values for the distribution coefficient for cadmium were extracted from the literature (K_d=2.9–4.7 log l/kg).The range of K_d values obtained from the field data was used to perform model simulations for cadmium, in order to determine the sensitivity of the model to the distribution coefficient. The modelled yearly averaged concentrations of dissolved cadmium at one location 10 km from the coast, ranged from 0.005–0.035 μg/l, depending on the magnitude of the K_d used in the simulation. These concentrations are low compared to measured values (0.053 μg/l) due to an underestimation of the cadmium input to the North Sea, or possibly the occurrence of bottom-water exchange processes which the model does not include.     

Diffusion coefficients of organics in high density polyethylene (HDPE)

Only limited data are available on the diffusion of volatile organic solvents through flexible membrane liners (FMLs) used for lining impoundments and landfills. To expand this database, a rapid, inexpensive method is needed to measure the diffusion coefficients of volatile organic solvents through FML materials. An absorption method has been developed to determine the diffusion coefficients of volatile organic solvents through FML materials. The method is based on the depletion of an organic compound from an aqueous solution due to absorption by a submerged sample of FML. A numerical solution of Fick's second law of diffusion was used to develop a graph which can be used to determine the diffusion coefficient from the time dependent concentration data. The diffusion coefficients obtained from the absorption tests were validated by comparing them with coefficients determined using a two chamber diffusion cell. The diffusion coefficients determined for toluene and xylene in high density polyethylene (HDPE) were 5.1 × 10⁻⁹ cm²s⁻¹ and 1.0 × 10⁻⁹ cm²s⁻¹ by the two methods, respectively. The data indicate that the coefficient of distribution (K_d) between the FML and the organic solution, a value which is needed to calculate the diffusion coefficient from the data, can be estimated from the log of the octanol-water partition coefficient (K_ow), a commonly measured and reported value for many chemicals.     

Integration of the Pesticide Impact Rating Index with a Geographic Information System for the Assessment of Pesticide Impact on Water Quality

The pesticide impact rating index (PIRI) has been integrated with a Geographic Information System (GIS) to enable regional assessment of pesticide impact on groundwater and surface water resources. The GIS version of PIRI (PIRI-GIS) was used to assess the impact of pre-planting atrazine use in the pine plantations on the Gnangara Mound, Western Australia. The impact on groundwater was found to be spatially variable, mainly dependent on soil type and depth to groundwater, because land use variables were spatially constant. Areas with the greatest impact on groundwater were those where the soil had a low sorption capacity for atrazine. Knowledge of the spatial distribution of the sorption coefficient based on organic carbon (K _oc) for atrazine was found to significantly improve the results from PIRI-GIS. Average values for K _oc (i.e. based on overseas data) were too low for most of the local soil types, resulting in a general overestimation of pesticide impact on groundwater resources, but an underestimation of impact in areas that should be of greatest concern (i.e. where the soil has a low sorption capacity for atrazine).     

Effect of soil solids concentration in batch tests on the partition coefficients of organic pollutants in landfill liner-soil materials

 The effect of the soil solids concentration in batch tests on the measured values of the partition coefficient (K _p) of organic pollutants in landfill liner-soil material was investigated. Since this study was based on the results of batch and column tests conducted independently, there were limitations to the conclusions derived. The organic compounds tested were benzene, methylene chloride, toluene, trichloroethylene, and p-xylene. The results of this study showed that as soil solids concentrations increased, the measured K _p values of these organic compounds strongly decreased. The observed values of K _p stabilized when the soil solids concentration was above a certain value. Typical K _p values obtained from batch tests conducted under high soil solids concentrations were close to those obtained from column tests. It was concluded that the K _p values of organic compounds measured under low soil solids concentrations, i.e., less than 100 g/l, may not correctly simulate the field situation. Consequently, the values of K _p obtained with low soil solids concentrations can result in an overestimation of the retardation factor of the landfill liner material. Received: March 14, 2002 / Accepted: August 25, 2002     

Determining distribution coefficients for low cost adsorbents

As with other construction materials, coal fly ash contains trace metals that can leach into the natural environment. As part of a broader effort to encourage appropriate coal combustion product use in infrastructure applications (e.g., road construction, stabilization, and structural fill), this study evaluated traditional and low‐cost adsorbent alternatives for their capacity to attenuate trace metals. Batch sorption tests were used as a preliminary screen for a wide variety of low cost (e.g., steel byproducts, rubber dust, and compost) and innovative materials (e.g., kudzu, biofilm, and pond weed) as well as conventional materials (activated carbon, alumina, and zeolites). The removal rates were demonstrated in this study by observing the calculated distribution coefficient (K_d) which were determined using a program called MATLAB. Limestone and steel byproducts were found to be particularly effective with large K_d values of 15,740, 1,520, and 540 L kg^?1 for cadmium, chromium, and selenium and, for ladle refractory and mill scale, K_d values of 3,910, 670, and 1,760 L kg^?1 were observed. Among the three metals tested for this study, it was observed that most low cost and innovative materials removed cadmium quite efficiently; however, the removal of selenium and chromium depended on the substrate and prevailing pH. In general, these results suggest that alternative materials may have relevance in niche applications where leaching is a concern that can be addressed through enhanced attenuation capacity via blending or layering of adsorbents.     

Streambed Sediment Geochemical Controls on In-Stream Phosphorus Concentrations during Baseflow

A spatially extensive geochemical data set of stream water and bed sediment composition across the Tamar catchment in south-west England was analysed to identify the key bed sediment properties that control the in-stream dissolved reactive phosphorus (DRP) concentrations during baseflow conditions. Linear regression analysis of the streamwater DRP concentrations and the distribution coefficient K _d for DRP revealed that the former is positively correlated with total SiO₂ and Al₂O₃, and negatively correlated with K₂O. The primary control on these major element distributions is the dominant bedrock geology. The data suggest that streamwater DRP concentrations are mainly controlled by adsorption to clay minerals. Where P concentrations in streamwater were considerably elevated by inputs from point sources, DRP concentrations are also controlled by precipitation of hydroxyapatite.     

Dry-thermophilic anaerobic digestion of organic fraction of municipal solid waste: methane production modeling

The influence of particle size and organic matter content of organic fraction of municipal solid waste (OFMSW) in the overall kinetics of dry (30% total solids) thermophilic (55 °C) anaerobic digestion have been studied in a semi-continuous stirred tank reactor (SSTR). Two types of wastes were used: synthetic OFMSW (average particle size of 1 mm; 0.71 g Volatile Solids/g waste), and OFMSW coming from a composting full scale plant (average particle size of 30 mm; 0.16 g Volatile Solids/g waste).A modification of a widely-validated product-generation kinetic model has been proposed. Results obtained from the modified-model parameterization at steady-state (that include new kinetic parameters as K, Y_pMAX and θ_MIN) indicate that the features of the feedstock strongly influence the kinetics of the process. The overall specific growth rate of microorganisms (μ_max) with synthetic OFMSW is 43% higher compared to OFMSW coming from a composting full scale plant: 0.238 d⁻¹ (K = 1.391 d⁻¹; Y_pMAX = 1.167 L CH₄/gDOC_c; θ_MIN = 7.924 days) vs. 0.135 d⁻¹ (K = 1.282 d⁻¹; Y_pMAX = 1.150 L CH₄/gDOC_c; θ_MIN = 9.997 days) respectively.Finally, it could be emphasized that the validation of proposed modified-model has been performed successfully by means of the simulation of non-steady state data for the different SRTs tested with each waste.     

Influence of groundwater conditions and co‐contaminants on sorption of perfluoroalkyl compounds on granular activated carbon

Per and polyfluoroalkyl substances (PFAS) are emerging and persistent organic pollutants that have been detected in many environmental media, humans, and wildlife. A common method to effectively remove PFAS from water is adsorption by activated carbon. Preliminary sorption experiments were conducted using five characterized Calgon Corporation coal‐based granular activated carbon (GAC; F100, F200, F816, F300, and F400), one coconut‐based GAC (CBC‐OLC 12 × 30), and one Jacobi Corporation coal‐based GAC (Omni‐G 12 × 40). Sorption of four representative PFAS onto each GAC was measured to select the most favorable carbon sources. F400 and CBC were chosen based on their performance in preliminary PFAS sorption experiments and contrasting properties. Freundlich and Langmuir isotherm models were developed for perfluorooctanoic acid (PFOA) and perfluorooctanoic sulfonate (PFOS) at an initial concentration of 1 mg/L. Sorption capacities were determined for PFOA and PFOS individually and in the mixture. Individual compounds showed higher sorption than when present in the mixture for both PFOA and PFOS. PFOS showed higher sorption than PFOA both individually and in the mixture and F400 showed higher sorption capacity than CBC. The presence of co‐contaminants (kerosene, trichloroethylene, and ethanol), and variations in groundwater conditions (pH, presence of anions, naturally occurring organic matter, and iron oxides) demonstrated limited impact on the sorption of PFAS onto GAC under the experimental conditions tested.     

Removal of substituted phenols onto iron‐treated Nostoc sp. biomass

This study explored the possibility of removing 4‐nitrophenol (4‐NP) and 2,4‐dichlorophenol (2,4‐DCP) from water by using a dead blue‐green algae, Nostoc sp., dried and untreated and dried and treated with iron (Fe‐treated with 0.1 M ferric chloride solution for 1 day). The Nostoc sp. untreated and Fe‐treated biomass were used to study the sorption and desorption of 4‐NP and 2,4‐DCP. The effects of solute concentration, ionic strength, and temperature on sorption and desorption in the presence of untreated and treated Nostoc sp. biomass were investigated. The Fe‐treated Nostoc sp. biomass sorbed higher amounts of both 4‐NP and 2,4‐DCP than the untreated biomass. The percent cumulative desorption decreased from 6.41% to 0.28% and 1.84% to 0.19%, respectively, for 4‐NP and 2,4‐DCP for the Fe‐treated biomass. Biosorption of 4‐NP and 2,4‐DCP onto untreated and Fe‐treated Nostoc sp. biomass conformed to Freundlich isotherms. Iron treatment of Nostoc sp. biomass increased the value of ln K from 8.07 to 8.59 for 4‐NP and from 8.04 to 8.51 for 2,4‐DCP but decreased their desorption. An increase in ionic strength (0.003–0.03) increased the biosorption of both substituted phenols and decreased their percent desorption. An increase in temperature in the range of 15–35°C decreased the sorption of 4‐NP and 2,4‐DCP onto both untreated and Fe‐treated Nostoc sp. biomass and increased their desorption, indicating that the biosorption of both substituted phenols onto untreated and Fe‐treated Nostoc sp. biomass was principally a physical process. The results of this study suggest that Fe‐treated dried Nostoc sp. biomass could be explored as an inexpensive and eco‐friendly material for the effective removal of these phenols and, potentially, other chemicals from industrial wastewater and contaminated groundwater.     

Compost mixture influence of interactive physical parameters on microbial kinetics and substrate fractionation

Composting is a feasible biological treatment for the recycling of wastewater sludge as a soil amendment. The process can be optimized by selecting an initial compost recipe with physical properties that enhance microbial activity. The present study measured the microbial O₂ uptake rate (OUR) in 16 sludge and wood residue mixtures to estimate the kinetics parameters of maximum growth rate μ_m and rate of organic matter hydrolysis K_h, as well as the initial biodegradable organic matter fractions present. The starting mixtures consisted of a wide range of moisture content (MC), waste to bulking agent (BA) ratio (W/BA ratio) and BA particle size, which were placed in a laboratory respirometry apparatus to measure their OUR over 4 weeks. A microbial model based on the activated sludge process was used to calculate the kinetic parameters and was found to adequately reproduced OUR curves over time, except for the lag phase and peak OUR, which was not represented and generally over-estimated, respectively. The maximum growth rate μ_m, was found to have a quadratic relationship with MC and a negative association with BA particle size. As a result, increasing MC up to 50% and using a smaller BA particle size of 8–12 mm was seen to maximize μ_m. The rate of hydrolysis K_h was found to have a linear association with both MC and BA particle size. The model also estimated the initial readily biodegradable organic matter fraction, MB₀, and the slower biodegradable matter requiring hydrolysis, MH₀. The sum of MB₀ and MH₀ was associated with MC, W/BA ratio and the interaction between these two parameters, suggesting that O₂ availability was a key factor in determining the value of these two fractions. The study reinforced the idea that optimization of the physical characteristics of a compost mixture requires a holistic approach.     

The effect of bed properties on methane removal in an aerated biofilter--model studies

The capacity of laboratory-scale aerated biofilters to oxidize methane was investigated. Four types of organic and mineral-organic materials were flushed with a mixture of CH₄, CO₂ and air (1:1:8 by volume) during a six-month period. The filter bed materials were as follows: (1) municipal waste compost, (2) an organic horticultural substrate, (3) a composite of expanded perlite and compost amended with zeolite, and (4) the same mixture of perlite and compost amended with bentonite. Methanotrophic capacity during the six months of the experiment reached maximum values of between 889 and 1036 g m⁻² d⁻¹. Batch incubation tests were carried out in order to determine the influence of methane and oxygen concentrations, as well as the addition of sewage sludge, on methanotrophic activity. Michaelis constants K_M for CH₄ and O₂ were 4.6-14.9%, and 0.7-12.3%, respectively. Maximum methanotrophic activities V_max were between 1.3 and 11.6 cm³ g⁻¹ d⁻¹. The activity significantly increased when sewage sludge was added. The main conclusion is that the type of filter bed material (differing significantly in organic matter content, water-holding capacity, or gas diffusion coefficient) was not an important factor in determining methanotrophic capacity when oxygen was supplied to the biofilter.     

Comparison of percolation to batch and sequential leaching tests: Theory and data

Leaching tests are becoming more relevant in assessing solid waste material, particularly with respect to groundwater risks. In the field, water infiltration is the dominant leaching mechanism, which is simulated in the lab with batch and column tests. In this study, we compared percolation, through analytical solutions of the advection–dispersion equation, to laboratory batch and sequential leaching tests. The analytical solutions are supported with comprehensive data from various field and laboratory leaching of different solutes from waste materials and soils collected in long-term joint research projects funded by the German Federal Ministry for Education and Research and the Federal Environment Agency. The comparison of theory and data is facilitated if concentrations and cumulative release are plotted versus the liquid–solid ratios (LS). Both theory and data indicate that leaching behaviour is independent of duration and physical dimensions of the leaching tests. This holds even if field lysimeters are compared to laboratory columns of different size, different flow velocities as well as different contact times. In general, laboratory batch tests over predict effluent concentrations (for LS < K_d). Leaching of solutes from solid samples of certain materials (e.g. chloride from incineration ashes or sulphate from demolition waste) in column and lysimeter tests compares very well and agrees with the analytical solutions. Overall, reproducibility and agreement with theory of column tests are better than batch tests, presumably because the latter are prone to artefacts (e.g. in liquid–solid separation steps). Theory and data fit surprisingly well, despite the fact that the theory is based on the local equilibrium assumption; non-linear sorption and chemical reactions in the solid waste materials are not considered.     

Terrestrial physical and chemical processes for liquid waste treatment

Experiences gained from full-scale evaluation of advanced treatment processes used for reclaiming wastewaters should help in the evaluation of potential treatment systems for treatment and reuse of water in space. Water Factory 21 is a 0.66 m³s⁻¹ (15 million gallons per day) water reclamation plant in California that has been in operation since 1976. The plant receives biologically treated wastewater. Lime treatment is effective for removal of heavy metals. Volatile organic constitutes are efficiently removed by air stripping. Non-volatile organic constituents are removed by activated carbon adsorption and reverse osmosis (RO). RO is a highly effective polishing step, and removes most of the remaining materials including inorganic salts, heavy metals, and organics. RO removed 85% of the total organic carbon, down to about 1 mg 1⁻¹, which is lower than in many treated drinking waters. The series of treatment processes used insured virus and pathogen removal, with lime treatment and chlorination together proving highly effective. Sufficient data has been collected to provide statistically reliable confidence limits to be set on the performance of each unit process.     

Effective Removing of Remazol Black B by the Polyacrylamide Cryogels Modified with Polyethyleneimine

In this study, modified polyacrylamide (PAAm) cryogels with high dye holding capacity were synthesized with an easily and cheaply process and adsorption of Remazol Black B (RBB) with the synthesized materials was investigated. Firstly, PAAm cryogels were synthesized with free radical cryo-copolymerization method and they were modified with Hofmann reaction to form amine groups in the structure of the cyrogels. Then, to increase the removal efficiency of cryogels, polyethylenimine (PEI) molecules were crosslinked onto the cryogels via NH₂ groups present in the PAAm gels modified by the Hofmann reaction. The original and modified cryogels were characterized with fourier transformed infrared spectroscopy, ¹³C nuclear magnetic resonance spectroscopy, scanning electron microscopy and thermogravimetric analysis. The point of zero charge (pH_pzc) of the modified cryogels was found to be 7.13 and RBB removing capabilities of PEI-modified PAAm cryogels were investigated at pH between 2 and 7. In addition, the adsorption treatments were performed at different process time, incubation temperature, initial dye concentration and adsorbent amount to find maximum removal capacity of the adsorbent. The modified cryogels adsorbed maximum amount of RBB at pH 2 and the sorption process reached equilibrium in 6 h. It was observed that the adsorption efficiency did not change much with the increase in temperature. The maximum RBB removal capacity of the modified cyrogels was determined to be 201 mg/g when the initial RBB concentration was 200 mg/L, treatment time was 6 h at pH 2. Moreover, the adsorption of RBB dye with the modified cryogels takes place with a second order kinetic and RBB dye adsorption data showed compliance with the Langmuir isotherm. The findings of the study expose that the obtained PEI-modified PAAm cryogels are a hopeful material for RBB removal in aqueous environment.

     

Assessment of Potential Capability of Water Bamboo Leaves on the Adsorption Removal Efficiency of Cationic Dye from Aqueous Solutions

Removal of toxic pollutants from water and wastewater is becoming an important process with the increase of industrial activities. The present study focused on assessing the suitability and efficiency of water bamboo leaves (WBL) for the removal of cationic dye from aqueous solutions. The effect of different variables in the batch method including solution pH (2–12), initial dye concentration (50–250 mg L^?1), adsorbent dose (0.05–0.30 g), contact time (5–180 min) and temperature (283–333 K) on the dye removal was investigated. The adsorption kinetics was discussed in view of four kinetics models. The results showed that the pseudo-second-order kinetics model described dye adsorption on WBL very well. The experimental equilibrium data were also tested by four isotherm models. It was found that adsorption of dye on WBL fitted well with the Langmuir isotherm model, implying the binding energy on the whole surface of the adsorbent was uniform and the dye molecules onto the surface of the adsorbent were monolayer coverage. Calculation of various thermodynamic parameters of the adsorption process indicated feasibility and exothermic nature of dye adsorption.     

Photochemical Degradation of Aqueous Polyvinyl Alcohol in a Continuous UV/H<Subscript>2</Subscript>O<Subscript>2</Subscript> Process: Experimental and Statistical Analysis

Polyvinyl alcohol (PVA), being a dominant contributor of total organic carbon (TOC) in textile wastewater, is not easily degradable by conventional methods of wastewater treatment. This study investigates the degradation of aqueous PVA in a continuous UV/H₂O₂ photoreactor since the feeding strategy of hydrogen peroxide proves to have considerable effects on the process performance. Response surface methodology involving the Box–Behnken method is adopted for the experimental design to study the effects of operating parameters on the process performance. Experimental analysis shows that the TOC removal varies from 16.11 to 42.70 % along with a reduction of the PVA molecular weights from 56.7 to 95.3 %. The TOC removal is significantly lower than the molecular weight reduction due to the generation of the intermediate products during oxidation. Operating the UV/H₂O₂ process in a continuous mode facilitates the degradation of highly concentrated polymeric solutions using a relatively small hydrogen peroxide concentration in the feed with a small residence time ranges from 6.13 to 18.4 min.     

Balance of NH3 and behavior of polychlorinated dioxins and furans in the course of the selective non-catalytic reduction of nitric oxide at the TAMARA waste incineration plant

Investigations were performed on the selective non-catalytic reduction (SNCR) of nitric oxide (NO) at TAMARA, the pilot-scale waste incineration plant of the Karlsruhe Research Center. Aqueous ammonia (NH₃) was injected into the combustion chamber as reductant. The influence of NH₃ on various inorganic and organic compounds in the flue gas was investigated. The concentrations of NO were reduced by up to about 90% by NH₃ injection. The concentrations of most of the other inorganic and organic compounds, including in particular PCDD and PCDF, did not change significantly.