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The present study investigated the phycoremediation efficacy of two freshwater green microalgae Chlorella ellipsoidea and Desmodesmus opoliensis for treatment of water of Ellenga beel, a wetland located in the vicinity of Nagaon paper mill and into which effluents of the paper mill are drained-off. After inoculation of water samples with the two freshwater green microalgae, the culture medium were analyzed for various physicochemical parameters such as pH, electrical conductivity, total dissolved solids, phosphate, nitrate, potassium, chloride, phenol, cyanide, biological oxygen demand, chemical oxygen demand and heavy metals at every seven days interval for a period of 42 days. A reduction of phosphate (85%), sulfate (96%), nitrate (76%) and chloride (48%) was observed after 42 days of incubation in the tested beel water. The micro algal incubation also resulted in decrease of heavy metal such as Pb (54%), Zn (98%), Cr (59%), and Cu (61%). Comparison of Fourier transform infrared spectra of beel water samples (control) with those inoculated with the test micro algal species showed presence of binding sites for certain functional groups like phosphate, amide, carbohydrate and alkyl halides in inoculated samples. D. opoliensis exhibited higher phycoremediation efficiency than C. ellipsoidea in removal of pollutants from the beel water samples. [ABSTRACT FROM AUTHOR]

Industrial processes and municipal wastes largely contribute to the fluctuations in iron (Fe) content in soils. Fe, when present in unfavorable amount, causes harmful effects on human, flora, and fauna. The present study is an attempt to evaluate the composition of Fe in surface soils from paper mill and municipal landfill sites and assess their potential ecological and human health risks. Geochemical fractionation was conducted to explore the chemical bonding of Fe across different fractions, i.e., water-soluble (F1) to residual (F6). Different contamination factors and pollution indices were evaluated to comprehend Fe contamination extent across the study area. Results indicated the preference for less mobile forms in the paper mill and landfill, with 26.66% and 43.46% of Fe associated with the Fe–Mn oxide bound fraction (F4), and 57.22% and 24.78% in the residual fraction (F6). Maximum mobility factor (MF) of 30.65% was observed in the paper mill, and 80.37% in the landfill. The enrichment factor (EF) varied within the range of 20 < EF < 40, signifying a high level of enrichment in the soil. The individual contamination factor (ICF) ranged from 0 to >6, highlighting low to high contamination. Adults were found to be more vulnerable towards Fe associated health risks compared to children. The Hazard Quotient (HQ) index showed the highest risk potential pathways as dermal contact > ingestion > inhalation. The study offers insights into potential Fe contamination risks in comparable environments, underscoring the crucial role of thorough soil assessments in shaping land use and waste management policies. [Display omitted] • Geochemical fractionation unveils less bioavailable Fe in contaminated soil. • EF, ICF, and I geo indicate high Fe contamination. • Adults are more susceptible to potential health risks from surplus Fe exposure. • HQ analysis pinpoints dermal contact as the primary pathway for Fe exposure risks. [ABSTRACT FROM AUTHOR]

• Two sub-period division strategies with MPCA are evaluated in SBR process. • Correlations between the different stages of SBR process are considered. • Four SBR parameters of field data from paper mill are utilized for fault diagnosis. • Sub-period division strategy based on similarity principle demonstrates best. Fault diagnosis of sequential batch reactor (SBR), a widely applied wastewater treatment technology in papermaking industry with huge discharge, has been a significant challenge due to the inherent multi-period characteristics of the process. In this paper, based on the conventional multi-way principal component analysis (MPCA) method (Scenario 0), two sub-period division strategies based on the processing phases of SBR process (Scenario 1) and the similarities of the loading matrices between the adjacent time slices (Scenario 2) are proposed for the detection of faults. Combined with Scenario 0, using the field data of blower current, level of SBR reactor, dissolved oxygen of wastewater and the blower valve opening in the SBR process of paper mill, two different fault diagnosis models with Scenarios 1 and 2 are developed and evaluated, respectively. The study results revealed that, both the calculated statistics of T2 and sum of prediction errors (SPE) of the fault diagnosis models with Scenarios 1 and 2 could detect the faults and identify the fault locations and sources. Compared to Scenario 0 which neglects the correlations between the different stages of SBR process, the fault diagnosis model by Scenario 2 demonstrated a superiority ability in fault identification in terms of the fault's time onset and fault's sources with adequate accuracy. The results enable the feasible and reliable implementation of the developed sub-MPCA diagnosis model with Scenario 2 in the actual SBR plants. [ABSTRACT FROM AUTHOR]

A Midwestern pulp and paper mill had arc-flash ratings around 100 cal/cm2 on 50 480-V unit substations. New relays were installed to replace the existing protection and add light detection to improve arc-flash detection times. During a couple of one-day outages, sample installations took place. During the cold mill outage, 44 installations were completed over 12 days by working around the clock. Old relays were removed, new plates were mounted and wired in, and fiber sensors were routed through the buswork and into the breaker cubicles. Updated arc-flash studies show an average arc-flash rating reduction of 90%. [ABSTRACT FROM AUTHOR]

As a great amount of chemicals are employed to carry out the coating process of paper, the wastewater from paper mill making coated products is characterized by high levels of chemical oxygen demand (COD), colour, and total suspended solids (TSS). In this study, wastewater from a paper mill making coated products was treated by a sequencing batch biofilm reactor (SBBR) after a lab-scale coagulation, resulting in COD, colour, and TSS removal efficiencies of 87.7 ± 1.0%, 33.5 ± 5.2%, and 41.4 ± 3.7%, respectively, which exceeded the biological treatment performance in the paper mill. The removal of COD and colour was attributed to the removal of recalcitrant organic matter, and the removal of TSS was attributed to the biofilm. [ABSTRACT FROM AUTHOR]

A major reason for biomarker failure is the selection of candidate biomarkers based on inaccurate or incorrect published results. Incorrect research results leading to the selection of unproductive biomarker candidates are largely considered to stem from unintentional research errors. The additional possibility that biomarker research may be actively misdirected by research fraud has been given comparatively little consideration. This review discusses what we believe to be a new threat to biomarker research, namely, the possible systematic production of fraudulent gene knockdown studies that target under-studied human genes. We describe how fraudulent papers may be produced in series by paper mills using what we have described as a 'theme and variations' model, which could also be considered a form of salami slicing. We describe features of these single-gene knockdown publications that may allow them to evade detection by journal editors, peer reviewers, and readers. We then propose a number of approaches to facilitate their detection, including improved awareness of the features of publications constructed in series, broader requirements to post submitted manuscripts to preprint servers, and the use of semi-automated literature screening tools. These approaches may collectively improve the detection of fraudulent studies that might otherwise impede future biomarker research. [ABSTRACT FROM AUTHOR]

This study used data from the Retraction Watch website and from published reports on retractions and paper mills to summarize key features of research misconduct in China. Compared with publicized cases of falsified or fabricated data by authors from other countries of the world, the number of Chinese academics exposed for research misconduct has increased dramatically in recent years. Chinese authors do not have to generate fake data or fake peer reviews for themselves because paper mills in China will do the work for them for a price. Major retractions of articles by authors from China were all announced by international publishers. In contrast, there are few reports of retractions announced by China's domestic publishers. China's publication requirements for physicians seeking promotions and its leniency toward research misconduct are two major factors promoting the boom of paper mills in China. [ABSTRACT FROM AUTHOR]

Treatment of upflow anaerobic sludge blanket (UASB) effluent from a paper mill in aerated activated sludge reactors involves high aeration costs. Moreover, this calcium-rich effluent leads to problematic scale formation. Therefore, a novel strategy for the aerobic treatment of paper mill UASB effluent in microalgal bacterial floc sequencing batch reactors (MaB-floc SBRs) is proposed, in which oxygen is provided via photosynthesis, and calcium is removed via bio-mineralization. Based on the results of batch experiments in the course of this study, a MaB-floc SBR was operated at an initial neutral pH. This SBR removed 58 ± 21% organic carbon, 27 ± 8% inorganic carbon, 77 ± 5% nitrogen, 73 ± 2% phosphorus, and 27 ± 11% calcium. MaB-flocs contained 10 ± 3% calcium, including biologically-influenced calcite crystals. The removal of calcium and inorganic carbon by MaB-flocs significantly decreased when inhibiting extracellular carbonic anhydrase (CA), an enzyme that catalyses the hydration and dehydration of CO 2 . This study demonstrates the potential of MaB-floc SBRs for the alternative treatment of calcium-rich paper mill effluent, and highlights the importance of extracellular CA in this treatment process. [ABSTRACT FROM AUTHOR]

The paper industry is heavily using energy during all the phases of the manufacturing process. This is especially the case in Nordic mills where pressure ground wood is the source of fiber. The purpose of this case study is to show how energy consumption behaves on a monthly basis in a Finnish paper mill that has several paper machine lines. The research examines different categories of energy usage, as well as the overall costs. The results show that the monthly energy usage varies significantly. The electricity consumption of the case mill is rather steady, but there is significant monthly variation in steam and natural gas consumption. Moreover, steam and electricity unit costs increased significantly when coming to the end of the research period. The longitudinal case data shows that it is difficult to enhance energy consumption per produced unit at the paper mill. One reason for this is the bleak demand outlook for the end products, which often result in downsizing and closing operations inside the integrated unit. [ABSTRACT FROM AUTHOR]

This paper describes a new option for integrated recovery and esterification of carboxylates produced by anaerobic digestion at a pH above the pK a . The carboxylates (acetate, propionate, butyrate, valerate and lactate) are recovered using a strong anion exchange resin in the bicarbonate form, and the resin is regenerated using a CO 2 -expanded alcohol technique, which allows for low chemicals consumption and direct esterification. Paper mill wastewater was used to study the effect of pH and the presence of other inorganic anions and cations on the adsorption and desorption with CO 2 -expanded methanol. Calcium, which is present in paper mill wastewater, can cause precipitation problems, especially at high pH. Esters yields ranged from 1.08 ± 0.04 mol methyl acetate/mol of acetate in to 0.57 ± 0.02 mol methyl valerate/mol of valerate in . [ABSTRACT FROM AUTHOR]

Due to the huge amounts of wastewater discharge and the high pollution loads in papermaking industry, many greenhouse gases (GHG) are emitted in the papermaking wastewater treatment process. The wastewater dissolved oxygen (DO) control has been considered as the most cost-effective control solution for GHG reduction in wastewater treatment plants (WWTP). However, the competition between contaminant removal efficiency and GHG reduction hinders the drastic reduction of GHG emissions from WWTP. In this study, based on the established integrated GHG emission model, explicitly considering the total GHG reduction targets on the premise of effluent compliance, an intelligent control scheme has been developed for an activated sludge process in a paper mill. Regarding DO as the controlled variable, the proposed hierarchical optimal proportional-integral (HOPI) control scheme was established consisting of three layers: 1) Layer 1 for the effluent quality estimation, 2) Layer 2 for the optimal DO set point determined by genetic algorithm with the influent variations to obey discharging norms and reduce GHG emissions, 3) Layer 3 for the DO tracking proportional integral (PI) control with the controller parameters adjusted by the back propagation neural network to track the dynamically optimized DO set points. The simulation results showed that, compared with the open-loop (OL) operation (averaged aeration, 10/h), the proposed HOPI control (averaged aeration, 7.9/h) reduced the GHG emissions by 12.54% under the premise of discharging norms, which was mainly attributed to the reduction of the aeration electricity consumption. In contrast, the PI control (averaged aeration, 12.9/h) increased the GHG emissions by 7.48% compared with the OL operation. Thus, the proposed HOPI control strategy has demonstrated potential for the application of GHG reduction in industrial WWTPs. [ABSTRACT FROM AUTHOR]

Due to the huge amounts of wastewater discharge and the high pollution loads in papermaking industry, many greenhouse gases (GHG) are emitted in the papermaking wastewater treatment process. The wastewater dissolved oxygen (DO) control has been considered as the most cost-effective control solution for GHG reduction in wastewater treatment plants (WWTP). However, the competition between contaminant removal efficiency and GHG reduction hinders the drastic reduction of GHG emissions from WWTP. In this study, based on the established integrated GHG emission model, explicitly considering the total GHG reduction targets on the premise of effluent compliance, an intelligent control scheme has been developed for an activated sludge process in a paper mill. Regarding DO as the controlled variable, the proposed hierarchical optimal proportional-integral (HOPI) control scheme was established consisting of three layers: 1) Layer 1 for the effluent quality estimation, 2) Layer 2 for the optimal DO set point determined by genetic algorithm with the influent variations to obey discharging norms and reduce GHG emissions, 3) Layer 3 for the DO tracking proportional integral (PI) control with the controller parameters adjusted by the back propagation neural network to track the dynamically optimized DO set points. The simulation results showed that, compared with the open-loop (OL) operation (averaged aeration, 10/h), the proposed HOPI control (averaged aeration, 7.9/h) reduced the GHG emissions by 12.54% under the premise of discharging norms, which was mainly attributed to the reduction of the aeration electricity consumption. In contrast, the PI control (averaged aeration, 12.9/h) increased the GHG emissions by 7.48% compared with the OL operation. Thus, the proposed HOPI control strategy has demonstrated potential for the application of GHG reduction in industrial WWTPs. [ABSTRACT FROM AUTHOR]

This paper quantitatively investigates the compositions of the gaseous pollutants in the ambient air of a secondary fiber paper mill. Total volatile organic compounds (TVOC), formaldehyde (HCHO), sulfur compounds (H2S), and hydrocarbon compounds (CxHy) were analyzed on six sampling sites with photo-ionisation detector, acetylacetone spectrophotometric method, and gas detector. The results revealed that, the high levels of TVOC and CxHywere detected at the wet end of paper machine and the office area, respectively; all the H2S contents on the six sites exceeded the limit (0.06 mg m−3) seriously; the HCHO concentrations at other five sites were out of the limit (0.10 mg m−3) except for the wastewater treatment plant. Furthermore, the necessary discussions about the possible pollution sources were considered on the process flow, the chemical agents used, and the ambient conditions in the paper mill. For the sake of air pollution control in paper mills, these remarkable results and analysis lay some technical basis in the following researches that should attract more attentions. [ABSTRACT FROM AUTHOR]

Cogeneration is considered as one of the promising energy efficient techniques for producing electricity and useful thermal energy from a single fuel source. This paper describes a feasibility study of the implementation of different cogeneration options to a paper mill to evaluate their energy saving potentials and economic benefits. The investigated systems in this paper are gas turbine, steam turbine and combined cycle cogeneration options evaluated and compared based on energy utilisation factor and Annualised Life Cycle Cost (ALCC) analysis. The results of energy analysis show that all Combined Heat and Power (CHP) systems satisfy the thermal energy needs of the mill while the combined cycle cogeneration option generates the highest amount of electric energy equal to 10.91 MW. The gas turbine cogeneration system is shown as the most advantageous system from overall energy point of view with the highest energy utilisation factor of 78% meeting the heat and electric requirements of the mill and exporting 21,329 MWh of additional electricity to the grid. Economic feasibility results also show that an overall saving of 5.12 million US$ can be achieved by implementing the gas turbine cogeneration system to the mill making it as the best cogeneration option with the least overall ALCC of 1.34 million US$ and the maximum percentage of CO 2 emission reduction (68%) when compared with the other options. [ABSTRACT FROM AUTHOR]

Due to increasing generation of solid wastes from papermaking industry, major concerns arise about the disposal of the solid wastes and their adverse impacts on environments, in which the disposal of paper sludge massively produced from paper mills has become one of the most serious solid waste problems worldwide. In this study, laboratory experiments were conducted to evaluate the feasibility and applicability of incorporating solid wastes from paper mills into controlled low strength material (CLSM), in which fly ash was used as a substitute for cement, bottom ash was added by partially replacing fine aggregate, and paper sludge was treated as a fibrous admixture. Results show that both fly ash and bottom ash could be effectively used in production of CLSM mixtures with desired performances. By limiting the amount of cement used in the mixture, the ultimate strength of CLSM could be controlled for easy excavation. Fly ash could effectively increase flowability of the mixture, thus improving self-compactibility. Both bottom ash and paper sludge had an adverse effect on the flowability. The strength of CLSM was reduced when a higher content of fly ash was incorporated to replace cement, while the strength was increased when more river sand was replaced with bottom ash. Due to a high water absorption and poor dispersibility of paper sludge, the CLSM made with additional paper sludge exhibited a relatively low flowability and a reduction in strength. However, with proper mixture design, paper sludge could still be effectively used in CLSM. [ABSTRACT FROM AUTHOR]

In this work, volatile organic compounds (VOCs) in the ambient air of a secondary fiber paper mill were analyzed. For the sake of studying pollution comprehensively, four sites in the paper mill were analyzed and active sampling methods were used. Desorption was carried out with two solvents, carbon disulfide and dichloromethane. The compositions of VOCs were determined by gas chromatography-mass spectrometry (GCMS) method. The main identified substances in the four sites were as follows: (1) waste paper sorting room: alkanes, phenols, and esters; (2) papermaking workshop: benzene series, alkanes, ethers, and phenols; (3) vacuum pump outlet: benzene series and phenols; and (4) office area: benzene series and phenols. Two main toxic substances in VOCs, the benzene series and phenols, were detected in the ambient air of the paper mill. The benzene series existed in three places along the main process of the paper mill and even existed in the office area, which was far away from the production line. Additionally, phenols were detected in all sampling locations in the paper mill. [ABSTRACT FROM AUTHOR]

Slime deposition on paper is a major problem confronted in paper-mills resulting in spoiled quality of the final product and huge economic losses. Conventional methods use chemical biocides for slime eradication which lead to effluent toxicity. Eco-friendly compounds can be used as alternatives for inhibition of biofilm/slime formation by bacteria. Autoinducer-2 (AI-2) based quorum sensing (QS) is a universal communication mechanism present in bacteria. In this study, bacteria isolated from paper-mill slime samples were identified for biofilm forming potential and AI-2 activity. Natural and synthetic compounds from PubChem library were selected by docking with AI-2 producer-LuxS, and were tested for inhibition of biofilm formation by the consortium of all paper-mill bacterial isolates. Triclosan was found to be the best as it reduced the expression of luxS and inhibited biofilm formation, as shown by Field Emission Scanning Electron Microscope (FE-SEM), to 50% at a concentration of 23.43 μg/ml and acted as biocide at 30 μg/ml for complete inhibition of growth when tested in the Research and development (R and D) set-up of paper mill. The pleiotropic inhibition of bacterial communities in paper mills by triclosan at environmentally safe concentrations can therefore stop slime formation and paper deterioration in an eco-friendly way and can prevent economic losses. • Thermophilic bacteria from paper-mill formed biofilm and showed AI-2 quorum sensing. • Triclosan docked molecularly with AI-2 producer (LuxS) and inhibited its expression. • Commercial grade triclosan inhibited bacterial consortium biofilm/slime formation. • Triclosan acted as biocide at 30 μg/ml in R and D set-up of paper mill. [ABSTRACT FROM AUTHOR]

The eicosapentaenoic acid (EPA) containing marine microalga Nannochloropsis oculata was grown in an effluent from anaerobic digestion of excess activated sludge from a wastewater treatment plant serving a combination of a pulp and a paper mill and a municipality (digester effluent, DE), mixed with the effluent of the same wastewater treatment plant. The maximum specific growth rate and photosynthesis of N. oculata were similar in the DE medium and in artificial sea water medium (ASW) but after 7 days, algae grown in the DE medium contained seven times more triacylglycerols (TAGs) per cell than cells grown in ASW, indicating mild stress in the DE medium. However, the volumetric rate of EPA production was similar in the ASW and DE media. The results suggest that N. oculata could be used to produce EPA, utilizing the nutrients available after anaerobic digestion of excess activated sludge of a pulp and paper mill. [ABSTRACT FROM AUTHOR]

The paper production process is significantly affected by direct and indirect effects of microorganism proliferation. Microorganisms can be introduced in different steps. Some microorganisms find optimum growth conditions and proliferate along the production process, affecting both the end product quality and the production efficiency. The increasing need to reduce water consumption for economic and environmental reasons has led most paper mills to reuse water through increasingly closed cycles, thus exacerbating the bacterial proliferation problem. In this work, microbial communities in a paper mill located in Italy were characterized using both culture-dependent and independent methods. Fingerprinting molecular analysis and 16S rRNA library construction coupled with bacterial isolation were performed. Results highlighted that the bacterial community composition was spatially homogeneous along the whole process, while it was slightly variable over time. The cultureindependent approach confirmed the presence of the main bacterial phyla detected with plate counting, coherently with earlier cultivation studies (Proteobacteria, Bacteroidetes, and Firmicutes), but with a higher genus diversification than previously observed. Some minor bacterial groups, not detectable by cultivation, were also detected in the aqueous phase. Overall, the population dynamics observed with the double approach led us to hypothesize a possible role of suspended bacteria in the re-formation mechanisms of resistant biofilms. [ABSTRACT FROM AUTHOR]

Highlights: [•] An unique co-digestion strategy to improve degradation of rice straw was investigated. [•] Different ratios of piggery wastewater and paper mill sludge were used as inocula. [•] Specific methane yields above 330LCH4/kgVS were achieved in 92days. [•] Increased quantities of paper mill sludge directly increased hydrolysis of the straw. [•] The most stable digester contained equal parts of straw, wastewater and sludge. [Copyright &y& Elsevier]

This paper evaluates economically build a new cogeneration plant with clean energy from forest biomass company Norske Skog Bio Bio (NSBB). This is to show that this plant-based forest biomass for electricity generation is a viable option in Chile from the economic and environmental perspective. For this evaluation, we propose an approach that uses “real options theory" based on the application of log-transformed binomial method with six steps. Also, comparing the results obtained with this approach, the results using traditional methods. It is found that for all cases studied, the value yielded by the real options method was higher than estimated by traditional methods. It is concluded that this alternative profitable investment. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to present a hybridized technique for analyzing the behavior of an industrial system stochastically by utilizing vague, imprecise, and uncertain data. In the present study two important tools namely Lambda-Tau methodology and particle swarm optimization are used to formulate the hybridized technique PSOBLT (Particle swarm optimization based Lambda-Tau) for analyzing the behavior of the complex industrial system stochastically up to a desired degree of accuracy. Expressions of reliability indices like failure rate, repair time, mean time between failures (MTBF), expected number of failures (ENOF), reliability and availability for the system are obtained by using Lambda-Tau methodology and particle swarm optimization is used to construct the membership function. Fault tree is used to model the system. The press unit of a paper mill situated in a northern part of India, producing approximately 200 tons of paper per day, has been considered to demonstrate the proposed approach. Sensitivity analysis of a system's behavior has also been done. The behavior analysis results computed by PSOBLT technique have a reduced region of prediction in comparison of existing Lambda-Tau and GABLT (Genetic algorithm based Lambda-Tau) technique region, i.e. uncertainties involved in the analysis are reduced. Thus, it may be a more useful analysis tool to assess the current system conditions and involved uncertainties. Thus the paper suggests an approach to improve the systems' performance. [ABSTRACT FROM AUTHOR]

The disposal of untreated paper mill effluent is a major environmental concern today. The purpose of this paper is to highlight the available treatment units for the paper mill effluent and to recommend a possible best option for the developing nations, like Pakistan. Various physciochemicals, anaerobic, aerobic, combination of different treatment units have been evaluated, on the basis of their treatability performance, especially in terms of COD, BOD and AOX removal efficiency. It is concluded that the physcio-chemical and aerobic processes are uneconomical and impracticable, owing to their high operational cost. Whereas, the anaerobic processes seem to be more reliable, simple and feasible for the developing world, both in terms of pollution reduction and low operational costs. [ABSTRACT FROM AUTHOR]

Highlights: [•] Bioconversion of tea factory and paper mill coal ash is a novel effort. [•] Solubility of Cr and Ni in coal ashes is reduced due to vermiconversion. [•] Vermicomposted coal ashes improve soil health. [•] Vermicomposted tea factory coal ash enhances crop yield. [Copyright &y& Elsevier]

Abstract: The pulp and paper industry is one of the most energy-intensive industries worldwide. In 2007, it accounted for 5% of total global industrial energy consumption and 2% of direct industrial carbon dioxide (CO2) emissions. An energy audit is a primary step toward improving energy efficiency at the facility level. This paper describes a plant-wide energy audit aimed at identifying energy conservation and CO2 mitigation opportunities at a paper mill in Guangdong province, China. We describe the energy audit methods, relevant Chinese standards, methods of calculating energy and carbon indicators, baseline energy consumption and CO2 emissions of the audited paper mill, and nine energy-efficiency improvement opportunities identified by the audit. For each of the nine options, we evaluate the energy conservation and associated CO2 mitigation potential. The total technical energy conservation potential for these nine opportunities is 967.8terajoules (TJ), and the total CO2 mitigation potential is equal to 93,453tonnes CO2 annually, representing 14.4% and 14.7%, respectively, of the mill’s total energy consumption and CO2 emissions during the audit period. [Copyright &y& Elsevier]

Identifying the source and the distribution of bacterial contaminant communities in water circuits of industrial applications is critical even when the process may not show signs of acute biofouling. The endemic contamination of facilities can cause adverse effects on process runability but may be masked by the observed daily variability. The distribution of background communities of bacterial contaminants may therefore be critical in the development of new site-specific antifouling strategies. In a paper mill as one example for a full-scale production process, bacterial contaminants in process water and pulp suspensions were mapped using molecular fingerprints at representative locations throughout the plant. These ecological data were analyzed in the process-engineering context of pulp and water flow in the facilities. Dispersal limits within the plant environment led to the presence of distinct groups of contaminant communities in the primary units of the plant, despite high flows of water and paper pulp between units. In the paper machine circuit, community profiles were more homogeneous than in the other primary units. The variability between sampled communities in each primary unit was used to identify a possible point source of microbial contamination, in this case a storage silo for reused pulp. Part of the contamination problem in the paper mill is likely related to indirect effects of microbial activity under the local conditions in the silo rather than to the direct presence of accumulated microbial biomass. [ABSTRACT FROM AUTHOR]

Abstract: The use of paper-mill residuals in concrete formulations provides an alternative to landfill disposal. A response surface statistical methodology was carried out to model the influence on the slump and compressive strength of concrete containing paper-mill residuals with and without Class F fly ash replacement. The variables considered in this study included the water/cement ratio (w/c), paper-mill residual content and fly ash content to total cementitious material (FA/CM). The performance of the derived models to achieve good balance between the workability and compressive strength were further discussed by using the contour diagrams. The results showed that the compressive strength of concrete containing paper-mill residuals could be predicted from the referred slump value. [Copyright &y& Elsevier]

Abstract: The systematic, transparent and accurate on-line energy information of the production process is quite the basis of mill energy management and conservation. An Energy Management System (EMS) was built according to the characteristics of the energy usage in a typical newsprint paper mill. The EMS first realized the process data acquisition and integration, second fulfilled the on-line energy information calculation from the integrated data. A water and steam properties query component based on IAPWS-IF97 was developed and plugged into the EMS to facilitate the energy calculation of water and steam. The practical performance in the paper mill showed that the integrated energy information of the whole mill was gained and the on-line energy supervisory was achieved. In the end a systematic, transparent and accurate energy usage profile is obtained and it would provide the valuable fundamental energy data for the further energy analysis and optimization in the EMS. [Copyright &y& Elsevier]

Abstract: Water is critical to paper production and increasing competition from other users has reduced water availability to paper mills in recent years. The study was conducted at a large-scale integrated pulp and paper industry. The study conducted at laboratory for recycling of effluents was aimed at reducing water foot print of the paper mill. Paper machine section effluent was identified for treatment and reuse based on the flow and characteristics. Chemical aided clarification and simple membrane filtration systems were used for water recovery. Closing the water loop through suitable treatment for reuse of wastewater in the paper mills provides an assured and continuous source of water. Pollutant reductions at the rate of 87.5%, 75% and 89% were obtained on SS, COD and turbidity, respectively. Operational and capital costs were delineated for selection of treatment option and enhanced water recovery. Feasibility of micro/ultra filtration combination was assessed to reduce costs for water recovery. This combination removed up to 93% and 91.7% of SS and COD from the effluents. The treatment options assessed for water recovery reduced freshwater consumption by about 40% and the excess treated water was stored in ponds for process use during the lean season. [Copyright &y& Elsevier]

In order to characterize the pollution discharged into the Moselle River and some of its tributaries, spectroscopic techniques, namely UV-vis spectroscopy and synchronous fluorescence spectroscopy, have been combined. UV-visible spectra were analysed using the maximum of the second derivative at 225 nm (related to nitrates), the SUVA254 and E2/E3 indices (related to the nature of organic matter). Synchronous fluorescence spectra (Δ&#x03BB: = 50 nm) presented different shapes depending upon the type of pollution. The pollution results from anthropogenic activities: untreated domestic sewage due to misconnections in a periurban river, effluent from urban WWTPs, agricultural runoff (nitrates) in several streams, discharge from a paper mill (humic-like substances due to wood processing) and from steel mills (PAHs). [ABSTRACT FROM AUTHOR]

Abstract: In this study, the performance and the efficiency of physico-chemical effluent treatment in a paper mill was investigated, with the aim of evaluating the treatment rationality and running stability. The effluent treatment plant (ETP) uses alum as a coagulant and polyacrylamide as a flocculant in multi-stage water purification. Inadequate efficiency and some operational problems were observed and their occurrences were investigated. Several simple measures inside the mill and some technical measures can prevent or postpone expensive end-of-pipe treatment investments, such as biological treatment. Chemically enhanced primary treatment under optimal operating conditions can be a stand-alone technique for achieving high quality effluent. Furthermore, reductions in wastewater generation in combination with fiber and filler recovery provide environmental benefits as well as significant economic savings in production. The advantages of the cleaner production approach in existing treatment units compared to expensive biological end-of-pipe technologies are obvious. This study demonstrated that the examined mill could easily and cost-effectively change its water system toward strict discharge limits by continuing to use the existing treatment units. [Copyright &y& Elsevier]

Abstract: Aroclor 1242 contains a high percentage of lightly chlorinated congeners, which makes it susceptible to congener profile alterations as a result of physical–chemical environmental weathering by water washing, evaporation, and volatilization. The analysis of the variability of congener profiles in paper sludge samples using PCA, mixing models, and correlation (R 2) analysis, provided an integrated description of the behavior of Aroclor 1242 after its release in the environment. The results showed that the total PCB concentration decreased as the sample experienced weathering, with the congener profile of Aroclor 1242 shifting towards resembling heavier Aroclors as lighter congeners were lost. Mixing model analysis confirmed that a sample containing weathered Aroclor 1242 could easily be misidentified by laboratories as containing a mix of heavier Aroclors. The R 2 analysis showed that the profile of the congeners within a homologue group remained the same after weathering. This analysis showed that congeners that belong to the same level of chlorination behave similarly in such a manner that retains their overall profile when exposed to physical weathering. [Copyright &y& Elsevier]

Paper mills processing recycled paper suffer from biofouling causing problems both in the mill and final product. The total bacterial community composition and identification of specific taxa in the process water and biofilms at the stock preparation and paper machine areas in a mill with recycled paper pulp was described by using a DNA-based approach. Process water in a similar mill was also analyzed to investigate if general trends can be found between mills and over time. Bacterial community profiles, analyzed by terminal-restriction fragment length polymorphism (T-RFLP), in process water showed that the dominant peaks in the profiles were similar between the two mills, although the overall composition was unique for each mill. When comparing process water and biofilm at different locations within one of the mills, we observed a separation according to location and sample type, with the biofilm from the paper machine being most different. 16S rRNA gene clone libraries were generated and 404 clones were screened by RFLP analysis. Grouping of RFLP patterns confirmed that the biofilm from the paper machine was most different. A total of 99 clones representing all RFLP patterns were analyzed, resulting in sequences recovered from nine bacterial phyla, including two candidate phyla. Bacteroidetes represented 45% and Actinobacteria 23% of all the clones. Sequences with similarity to organisms implicated in biofouling, like Chryseobacterium spp. and Brevundimonas spp., were recovered from all samples even though the mill had no process problems during sampling, suggesting that they are part of the natural paper mill community. Moreover, many sequences showed little homology to as yet uncultivated bacteria implying that paper mills are interesting for isolation of new organisms, as well as for bioprospecting. [ABSTRACT FROM AUTHOR]

Abstract: Hyphenated techniques like Py-GC/MS (pyrolysis-gas chromatography/mass spectrometry) result often in complex chromatograms containing a high information density. Extracting meaningful information is difficult and time consuming. Especially with automatic sampling, data evaluation becomes a major bottleneck. An effective approach to automate the characterization of chromatograms is presented. The database approach consists basically of three steps: measuring reference substances to generate a database, measuring unknown or difficult samples and using the database for the identification of these samples. The compiled database contains a collection of mass spectra of pyrolysis products with data such as retention index and additional information from which reference substances the pyrolysis products may derive. The developed database approach has been tested on designed mixtures of compounds forming “white pitch”. “White pitch” is a typical type of deposit found in paper production processes deriving from chemicals used in coating processes. [Copyright &y& Elsevier]

Abstract: Retrofit process design can be seen as a multi-criteria decision-making (MCDM) problem aiming at selecting the best alternative for improving the performance of a chemical process. There is a growing consensus that environmental considerations, including the environmental impact associated with all life cycle stages of materials, should be integrated in chemical process design. Life cycle assessment (LCA) is a technique that allows quantification of those impacts. However, implementing this technique would increase the decision-making complexity and thus would necessitate systematic tools and methods. The analogy between LCA and MCDM has been recognized, but the systematic evaluation of LCA methodological choices and interpretation in this context is rarely discussed. The importance of those is demonstrated in this paper using a case study involving the implementation of de-inked pulp capacity and cogeneration and an integrated newsprint mill. [Copyright &y& Elsevier]

Annual ryegrass (Lolium perenne L.) is an important cool-season forage grass in the southeastern US. Since large portions of soils in this region are too acidic for optimum ryegrass production, there exists an opportunity to use lime mud waste from numerous regional pulp and paper mills as an agricultural liming material. In this study, four lime mud application rates, 2.25 (L1). 4.51 (L2), 9.01 (L3), and 22.50 (l4) ton ha-1 dry weight basis, and a control (L0) were evaluated for response to ryegrass growth during the first 6 weeks to estimate an optimum application range over the testing soil for future field test. Results indicated that applied lime mud slowed ryegrass germination and seedling emergence, with differences of whole plant length among treatments L0-L4 significant only during the first three weeks. Differences of whole plant dry weight among treatments L0-L4 reduced thereafter. The initial soil pH increase due to the lime mud application dropped in treatments L1-L4 by the end of the 6-week experiment. The optimum lime mud application range was estimated between L2 and L3, which provided higher ryegrass yields (kg ha-1) of 84 and 80 over 77 of the control and complied with the Code of Federal Regulation, CFR 40 Part 503 for land application. [ABSTRACT FROM AUTHOR]

Abstract: Paper industry generates a considerable amount of wastes. Their composition mainly depends on the type of paper produced and the origin of cellulose fibres. Nowadays, in Spain, 40% of solid wastes generated by the paper and pulp industry are deposited directly in landfill, 25% are used in the agriculture, 13% in the ceramic industry and 7% in the concrete production. In the last years, thermal treatment methods like combustion, pyrolysis and gasification have been widely study as alternative techniques for the valorization of different organic waste materials. The main objective of the present work is to study the pyrolysis behaviour of different paper mill waste materials. For this reason, a wide characterization of eight paper mill waste materials from different origins was performed using SEM, FTIR, DRX and thermogravimetric techniques. Paper mill sludges from recycled paper, mainly wastes obtained from deinking process, showed high CaCO3 and clays contents. Compared with the elevated total organic matter content (TOM) of paper mill waste materials their low organic carbon content determined by Cr2O7 2− oxidation reveals the elevated chemical stability of organic matter, due to high content on cellulose fibres. Analysis of samples by SEM indicates that successive recycled processes of paper leads to paper mill waste materials with more degraded fibres. XRD analyses show as crystalline cellulose was present in reject and primary sludge from paper mills that produced paper from virgin wood. However, crystalline cellulose content significantly decreased in waste materials from recycled paper. Finally, thermogravimetric analysis indicates that presence or mineral matter and degradation of cellulose significantly influences their pyrolysis behaviour. In general, weight loss of paper mill waste materials started at lower temperatures than pure cellulose. In waste materials from recycled paper weight loss continues at temperatures highest than 500°C due to kaolinite dehydration and carbonates decomposition. [Copyright &y& Elsevier]

Abstract: Between 2001 and 2004 a wear test was conducted in an operating Oregon paper mill. The objectives were to determine if there was a significant wear difference between two refiner alloys and to monitor and record wear while minimizing the impact on production. Four complete circles of plates were installed in a Sprout refiner. One circle was all Andritz A10 alloy, one was 17-4PH and the other two were alternating 17-4PH and A10 plates. Before installation and after removal bar height was measured with a micrometer. Wear surface replicas were taken five times during and after the test which started in August 2001 and ended in October 2004. It was found that 17-4PH wore at a slightly higher rate than the A10 in this application. The replica method of measuring and recording wear was very effective, producing data with good precision and accuracy and also minimizing disruption to the operating mill. [Copyright &y& Elsevier]

Abstract: Pulp and paper mills are one of the major effluent generating industries in the world. In most cases, mill effluent (treated or raw) is discharged back into a river, creek, stream or other water body; resulting in negative environmental impacts, as well as social concerns, among the downstream users. Pulp and paper mill effluent management, which could result in zero discharge into downstream water bodies, would present the best management option to address socio-environmental concerns. This paper presents such an effort aimed at closing the water cycle by using treated effluent from the mill to irrigate forage and fodder crops for producing animals feed. The treated effluent is delivered from the mill through gravity into a winter storage dam of 490ML capacity. For irrigation applications on 110ha of farmland, which is 42% of the total farmland, the water is pumped from the winter storage dam to five individual paddocks with Centre Pivot (CP) irrigators and one rectangular paddock with a Soft Hose Travelling (SHT) irrigator. From October 2001 to June 2006, a total of 2651mm of wastewater was applied at the farm. The impact assessment results, obtained from field monitoring, investigations and analysis, indicated that the closed water cycle effluent management strategy described had resulted in a lessening of the impact on water resources usually associated with paper mills. However, social attitudes to the use of crops that have been irrigated with recycled waters and the resulting impact on market value of the produce may still be a major consideration. [Copyright &y& Elsevier]

Abstract: Pulp and paper mill wastewater was characterizated, before (influent) and after (effluent) biological wastewater treatment based on an activated sludge process, by microfiltration (8, 3, 0.45 and 0.22μm) and ultrafiltration (100, 50, 30 and 3kDa) of the wastewater samples into different size fractions. Various parameters were measured on each fraction: molecular weight distribution (MWD) using high performance size exclusion chromatography (HPSEC), total organic carbon (TOC), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total phosphorus (Tot-P), phosphate phosphorus (PO4-P), electrical conductivity, pH, turbidity, charge quantity and zeta potential. The MWD, TOC and CODCr results indicated that the majority of the material present in both the influent and effluent was in the medium molecular weight (MW) range (i.e. MW<10kDa) with three main MW sub-fractions. There were no significant differences in the range of the MWD between the influent and effluent samples. The magnitude of the MWD in the effluent was about one half that in the influent, the greatest reduction being in the 6kDa fraction. The 3kDa fractions of both the influent and effluent showed a considerable increase in BOD7, probably due to the removal of compounds harmful to bacteria in 3kDa ultrafiltration. Influent turbidity decreased considerably in microfiltration (8–0.22μm). As the turbidity was removed by 0.22μm filtration, the anionic charge quantity started to decrease. Particles in the influent and effluent contained 19–29% and 14–20% of the total phosphorus, respectively. The major phosphorus fraction was in the form of soluble phosphate. [Copyright &y& Elsevier]

Progesterone, androstenedione, and androstadienedione were previously identified in the water and sediment of the Fenholloway River (Taylor County, FL, USA), a river that contains populations of masculinized female mosquitofish downstream of a paper mill, at levels higher than those in the nearby Spring Creek. Plant sterols, such as β-sitosterol in mill effluent derived from pine tree pulp, were suggested to be metabolized by bacteria to progesterone and androgens to account for the masculinization phenomenon. The current study made use of standard solid-phase methanol extraction procedures, high-performance liquid chromatography, liquid chromatography-mass spectrometry, and a cell-based, androgen-receptor transcription assay to determine naturally occurring progesterone levels in mature pine trees. Progesterone concentrations in the loblolly pine (Pinus taeda L.) were 49.34 ± 4.1 nmol/g dry mature wood (15.5 ± 1.29 μg/g), 12.26 ± 1.78 nmol/g pine needles (3.85 ± 0.56 μg/g), and 3.81 ± 0.36 nmol/g pine bark (1.19 ± 0.11 μg/g). The results suggest that naturally occurring progesterone from pine wood pulp contributes to increased progesterone levels downstream of paper mill effluent discharges and may serve as the natural steroid precursor for environmental androgen production that causes masculinization of female mosquitofish. [ABSTRACT FROM AUTHOR]

Aims: A public beach was frequently cited for health advisories because of high Escherichia coli levels, the source suspected to be a paper mill located upstream. This investigation sought to confirm whether or not the paper mill was the pollution source, and to characterize the risk to recreational bathers imposed by the source. Methods and Results: Quantification of E. coli in river water collected at incremental distances showed that paper mill effluent caused elevated E. coli levels in beach samples. Samples collected throughout the mill were variably positive for heterotrophic bacteria, total coliforms and E. coli, but negative for pathogenic E. coli O157 and Salmonella. Escherichia coli O157 or Salmonella spiked into mill samples (4·2 log10 or 5·6 log10 CFU per 100 ml, respectively) fell below detection levels within 14–24 h in raw (unaltered) samples, while in heat-sterilized replicates, the counts remained at initial levels or increased over 36 h. Conclusions: Pathogenic E. coli O157 and Salmonella were not isolated from paper mill samples. The absence of native bacteria allowed the survival of pathogens, while their presence accelerated pathogen decline. Significance and Impact of the Study: The co-existence of paper mill and swimming beach may be reasonable for now in spite of the limitations of an E. coli-based assay for beach water. [ABSTRACT FROM AUTHOR]

Abstract: From the utilization point of view, it is notable that the total element concentrations in the precipitated calcium carbonate (PCC) waste were significantly lower than the maximal allowable heavy metal concentrations for fertilizers used in agriculture and in forestry, set on the basis of the EU and Finnish legislation. The easily soluble Ca concentration of 168.5gkg−1 (d.w.) in PCC waste was 105 times higher than the typical value of 1.6gkg−1 (d.w.) in the coarse mineral soil in Finland indicates that the PCC waste is a potential agent for soil remediation and for improving soil fertility if it is used as fertilizer. According to a five-stage sequential extraction procedure, the highest concentrations of most of the elements occurred either in HF+HNO3 +HCl or H2O2 +CH3COONH4 fraction. This means that the major part of the elements retained in the PCC waste are not easy to extract (leach) under conditions normally found in nature. This is beneficial since, if inorganic materials and by-products are utilized in earth construction, the content of harmful compounds must be low and the harmful components must be tightly bound to the matrix. [Copyright &y& Elsevier]

The objective of this study was to commercially produce soda pulp and medium paper from empty fruit bunches (EFB) of Elaeis guineensis. In this work, EFB fibrous strands collected in Malaysia were shipped to China where they were pulped using a continuous pulping system. EFB soda pulp was shipped back to Malaysia for papermaking at three paper mills in Peninsular Malaysia. The EFB pulp was blended with recycled pulp from old corrugated container (OCC) at different ratios of blending to produce medium paper. Our results showed that EFB could be pulped by the soda process commercially. Evaluation of EFB soda pulp produced in this study had properties similar to pulps from two commercial hardwood species, namely, Acacia mangium and Eucalyptus globulus. [ABSTRACT FROM AUTHOR]

The operation of existing activated sludge treatment plants at paper mills in the world is often characterized by disturbances, caused by bad biosolids settling, sludge bulking, and reduction of biomass activity. This paper presents a comparison between the results obtained in a case study based on a full-scale activated sludge treatment (AST) system working as the only biotreatment and the AST working with anaerobic pretreatment by upflow anaerobic sludge blanket (UASB). The study was performed at paper mills in Hedera, Israel. The data was collected during 8 years. The anaerobic/aerobic system (2002–2004) provided steady operation performance, while the AST system without anaerobic pretreatment (1997–2001) produced effluent characterized by oscillatory values. The results indicate much lower levels of total suspended solids in the anaerobic/aerobic treatment system effluent, 5–10 mg/L, compared to 50–85 mg/L in the AST system only. Similar improvement was observed in terms of the organic matter removal: 220–250 mg/L vs. 80–120 mg/L as CODt, and 20–40 mg/L vs. 4–7 mg/L as BODt with low corresponding fluctuations. After the operation of the anaerobic pretreatment, the sludge age increased from 8–10 days to 30–40 days and the activated sludge performance substantially improved: the sludge volume index decreased from 200 to 80 mL/g with significant reduction of the excess sludge amount. The data collected during the operation monitoring clearly indicates that the anaerobic process followed by AST considerably reduced electrical and chemicals consumption in the biological treatment plant and provided low operational cost. [ABSTRACT FROM AUTHOR]

As opposed to effluents from chemical pulp production, very little is known about the endocrine potential of papermaking effluents. To evaluate the endocrine potential of biologically treated effluents from the main grades produced in Germany (fine, graphic and packaging papers), 16 samples were studied by means of the Recombinant Yeast Estrogen Assay (R-YEA). 10 samples were tested positive; seven of them were effluents from recovered paper processing mills. Possible sources of endocrine disruptors in addition to wood components include papermaking chemicals, paper converting chemicals, if recovered paper is used, and/or detrimental substances introduced by impurities in these chemicals. Six of the above samples were subjected to individual substance analyses to detect endocrinologically active or potentially endocrinologically active substances. Even though phthalate compounds were detected in concentrations between 0.46 and 2.36 micro;g/L, only two of the six samples were tested positive in the R-YEA, because the test fails to adequately detect this compound's class. Despite this drawback, the R-YEA will be used for further studies because of the great variety of potential endocrine substances present in paper mill effluents. In particular, mechanical and recycled fibre pulps as well as the constituents of chemical additives must be investigated in more detail. [ABSTRACT FROM AUTHOR]

The study was based on a full scale activated sludge plant (AS) compared to a parallel operated pilot membrane bioreactor (MBR) with flat sheets membranes. Both systems received their influent from an anaerobic bioreactor treating paper mill wastewater. MBR produced an effluent of much better quality than AS in terms of suspended solids, containing 1 mg/L or less in 80% of the monitoring time, while the AS effluent contained 12 mg/L, This could save the necessity of further treatment by filtration in the case of MBR. Other effluent quality parameters, such as organic matter (COD and BOD), phosphorus and ammonia nitrogen, did not indicate substantial differences between AS and MBR. Calcium carbonate scaling and formation of a bacterial layer on the membrane caused severe flux reduction. The membrane blockage because of scaling and biofouling proved to be vet/serious, therefore, it required proper and more complicated maintenance than the AS system. This study leads to the conclusion that in the ease of paper mill wastewater, after anaerobic biotreatment, if there is no need for excellent effluent quality in terms of suspended solids, the replacement of the AS by the MBR would not be strongly justified, mainly because of maintenance cost. [ABSTRACT FROM AUTHOR]

The fungus Pleurotus sajor-caju secretes phenol-oxidases that enable the use of recalcitrant compounds as substrates. The residues of paper manufacture contain high lignin levels, which gives the effluents a characteristic brownish colour. To test the potential of P. sajor-caju cultures on reducing these parameters, we used 90% of raw effluents from medium consistency oxygen delignification and bleaching stages plus 10% of mineral solution and different levels of glucose (5-15 g L-1) as substrate. We observed a greater fungal biomass in cultures using effluent than in controls. Cultures containing 10 to 15 g L-1 of glucose resulted in about 42% colour reduction. The polyphenol content was also reduced by 58.9% by the 13th day of culture. In addition, we observed the secretion of laccases (211.44 U mL-1 and 45.98 U mL-1 using ABTS and syringaldazine, respectively) and peroxidases (6.11 U mL-1-ABTS) both peaking at the 7th day of culture and with similar kinetics of production in different glucose concentrations. [ABSTRACT FROM AUTHOR]

This paper shows the methodology and results of the evaluation of the cleaning system of a Kraft paper mill. This evaluation was made keeping in mind variables of that system such as the pulp stock consistency percentage, ash content, air level in the pulp stock, and differential of pressure through the cleaners, for the analysis of a series of samplings carried out during the production of the different paper grades. On the basis of the results, possible modifications or improvements of the cleaning system were proposed, which will allow a reduction in pulp and water losses, energy consumption, and the amount of air required in the paper machine. [ABSTRACT FROM AUTHOR]

Abstract: Using data from the North Carolina School Asthma Survey about the respiratory health of 64,432 adolescents attending public schools in North Carolina and data provided by school employees about the environmental health conditions of the school buildings, we assessed the prevalence of daytime wheezing during the past year among students estimated to be exposed to air pollutants arising from pulp and paper mills located near the schools. Of the schools the students attended, 14% (37/266) were located within 30 miles of one or more pulp and paper mills and odor from the mills was identified by survey respondents for 9 of the 266 schools. The prevalences of daytime wheezing in smokers and nonsmokers with household cigarette smoke exposure were elevated among students attending schools located within 30 miles of a pulp and paper mill, compared to the prevalence among students attending schools located beyond 30 miles (⩽10 miles, prevalence ratio (PR): 1.21, 95% confidence interval (95% CI): 0.99, 1.43; 10–⩽30 miles, PR: 1.06, 95% CI: 0.96, 1.16) and among students attending schools with noticeable odor from a pulp and paper mill (PR: 1.12, 95% CI: 0.93, 1.31). These results indicate a possible association between paper mill location and wheezing symptoms among adolescents and suggest that community-based exposure to pulp and paper mill emissions may have a greater impact on smokers and individuals exposed to cigarette smoke in the home than on nonsmokers without such household exposure. [Copyright &y& Elsevier]