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A simple electrochemical approach has been strategically developed for in situ generations of ZnO nanoparticles using Zn rods as electrodes and hydrogen peroxide as the oxidant without the formation of any by-product. These ZnO nanoparticles were extended for remediation of pollutants present in paper mill effluents, and separation efficiency was found to be above 90% for hydrocarbons, 92% for lignin, 99% for phenol, and 93% of chemical oxygen demand (COD), as confirmed by gas chromatography-mass spectrometry and COD analysis. It was also observed that the experimental setup could successfully remove 99% of the color from the sample. These ZnO nanoparticles have been proven in the past to be antibacterial and were explored for its ability to inhibit the growth of both Gram-positive and Gram-negative bacteria in the effluent samples after the removal of toxic pollutants. Therefore, we proposed an electrochemical reaction for the in situ synthesis of ZnO nanoparticles for remediation of paper mill effluent as well as inhibit the bacterial growth in the treated effluent sample. [ABSTRACT FROM AUTHOR]

Abstract Phenol and its derivatives are pollutants present in the effluents of major industries such as paper mill, oil refineries and petrochemical plants. Removal of phenol from industrial effluent is extremely important because of its toxicity to the aquatic life and environment. In the present study, an attempt has been made to eradicate the phenol from wastewater using isolated bacteria from chronically contaminated effluent samples of a paper mill industry. The pH value of the effluent has been observed to be 8.2. The presence of high concentration of phenol has been observed in the effluent samples. The total sixteen bacterial isolates as obtained were checked for growth on minimal salt medium amended with different concentrations of phenol by flask culture technique. In the present study, the two isolate species of SP-4 and SP-8 were found to be very tolerant to degrade a phenol concentration up to 1800 mg/L.

Pollutants emerging from the effluents of paper mills eventually destroy the environment of our ecosystem. To find a proper solution of it, a cost-effective and environmentally benign technique is proposed here to remediate contaminants present in the effluent of paper mill in a sequential steps using advanced oxidation processes including Fenton reaction (FO) (Fe(II)/H2O2), modified Fenton oxidation (MFO) (Fe(II)/Zn(II)/H2O2) and biological flocculation process. A comparison and compilation among these techniques were carried out on the basis of the percentage removal of chemical oxygen demand (COD) as well as the observed degradation pattern in gas chromatography–mass spectrometry. Results revealed that MFO could remove ≥ 90% of COD at ~ 90 min, whereas FO could eliminate ≥ 80% COD at ~ 120 min. Further, the bioflocculation technique was found to reduce the heavy metal contents such as Fe, Mn, Zn, Co, Cd and Pb by ≥ 60%. In the sequential treatment process, lignin, phenolic and colour contents were also found to be reduced by ~ 84% ~ 97% and ~ 96%, respectively. Again, the bioassay tests were performed to verify the toxicity reduction in the industrial effluent after the application of the sequential treatment process. This study demonstrates that the sequential treatment technique could be an effective alternative for the treatment of paper mill effluent. [ABSTRACT FROM AUTHOR]

Biohydrogen and biomethane production via two stage sequencing system from paper mill effluent (PME) was evaluated to enhance its COD reduction. Heat-shock pretreatment of anaerobic sludge at 90 °C for 15 min was chosen to obtain a mixed microbial inoculum for dark fermentative hydrogen production. The effect of initial pH (5, 6 and 7) on the efficiency of hydrogen fermentation at different concentrations of substrate (3, 5 and 7 g-COD/L) was investigated, which the maximum hydrogen yield was obtained at initial pH 5. After that, the effects of substrate concentration (3, 5, 7, 10 and 15 g-COD/L) and fermentation temperature (37 and 55 °C) were investigated on the hydrogen production yield. The efficiency of dark hydrogen fermentation for all substrate concentrations was higher at 55 °C. The hydrogen production was enhanced as substrate concentration increased up to 5 g-COD/L, but then it was reduced, and the optimum hydrogen yield of 38.8 mL H 2 /g-COD initial was obtained at substrate concentration of 5 g-COD/L at 55 °C. The highest hydrogen (35.1 mL H 2 /g-COD initial) was obtained at 5 g-COD/L and 55 °C and the highest methane (553.8 mL CH 4 /g-COD initial) was obtained at 3 g-COD/L and 37 °C. Maximum COD reduction of 88.1% was obtained in two-stage sequencing dark fermentation/anaerobic digestion system at 3 g-COD/L and 37 °C. • BioH 2 and bioCH 4 were generated in expend of COD reduction from PME. • Effects of initial pH, COD loading and temperature were studied. • Primary step dark fermentation showed higher hydrogen yields at 55 °C. • Max COD reduction 88.1% was obtained in 2-stage sequencing system (3 g-COD/L, 37 °C). • 38.8 mL H 2 /g-COD initial at 55 °C and 553.8 mL CH 4 /g-COD initial at 37 °C were obtained. [ABSTRACT FROM AUTHOR]

The histopathological changes in the liver and kidney of Rasbora daniconius have been investigated after exposed to sublethal concentration of paper mill effluent. The result of acute toxicity shows that the paper mill effluent was highly toxic. The fish, Rasbora daniconius were exposed two sub-lethal concentrations of paper mill effluent [1.9% (1/5) and 0.95 % (1/10) LC50 of 96hr] for 30 days to study the impacts on the histology of liver and kidney. Histopathological examination reveled, swollen hepatocytes, nuclear hypertrophy, rupture sinusoids, hemorrhages, vacuolation in hepatic cells and broken central vein in liver. Kidney showed hypertrophy of hematopoietic tissues, cell necrosis, blocked glomerules with full of blood stain, dilated renal tubules with pyknotic nuclei and tubular necrosis. Histopathological changes were dose dependent. The results of histopathological changes in liver and kidney of Rasbora daniconius shows that, fish were under high stress during exposure to sublethal concentration of paper mill effluent. [ABSTRACT FROM AUTHOR]

Paper mill effluent (PME) was used as an organic feedstock for production of biohydrogen via dark fermentation using heat-shock pretreated anaerobic sludge under mesophilic conditions. The influence of substrate concentration (5, 10 and 15 g-COD/L) and the initial pH (5 and 7) on the efficiency of dark hydrogen fermentation from PME were investigated. The highest hydrogen yield of 55.4 mL/g-COD was obtained at substrate concentration and pH of 5 g-COD/L and 5, respectively. By increasing the concentration of substrate from 5 to 10 and 15 g-COD/L, at fixed initial pH, the hydrogen production efficiency was reduced from 55.4 mL/g-COD to 38.5 and 32.7 mL/g-COD. Furthermore, by increasing pH from 5 to 7, biohydrogen efficiency was reduced up to 40.8%. Different hydrolysis of PME including acidic, acidic-thermal and alkaline hydrolysis prior to fermentation were studied which the alkaline hydrolysis led to the highest hydrogen yield of 62.2 mL/g-COD. Moreover, methane production efficiency of 569 mL/g-COD was obtained at substrate concentration and pH of 5 g-COD/L and 7, respectively. Paper mill effluent (PME) was used as an organic feedstock for production of biohydrogen via dark fermentation using heat-shock pretreated anaerobic sludge under mesophilic conditions. The influence of substrate concentration (5, 10 and 15 g-COD/L) and the initial pH (5 and 7) on the efficiency of dark hydrogen fermentation from PME were investigated. The highest hydrogen yield of 55.4 mL/g-COD was obtained at substrate concentration and pH of 5 g-COD/L and 5, respectively. By increasing the concentration of substrate from 5 to 10 and 15 g-COD/L, at fixed initial pH, the hydrogen production efficiency was reduced from 55.4 mL/g-COD to 38.5 and 32.7 mL/g-COD. Furthermore, by increasing pH from 5 to 7, biohydrogen efficiency was reduced up to 40.8%. Different hydrolysis of PME including acidic, acidic-thermal and alkaline hydrolysis prior to fermentation were studied which the alkaline hydrolysis led to the highest hydrogen yield of 62.2 mL/g-COD. Moreover, methane production efficiency of 569 mL/g-COD was obtained at substrate concentration and pH of 5 g-COD/L and 7, respectively.

The present paper reports the heavy metal uptake by water lettuce (Pistia stratiotes L.) from paper mill effluent (PME) with its prediction modeling studies. Lab scale phytoremediation experiments were performed in glass aquariums to grow P. stratiotes in 0% (bore well water as a control), 25%, 50%, 75%, and 100% concentrations of PME. The influence of pH and heavy metal concentration in PME for the effective uptake and accumulation of heavy metal contents (∆Y: mg/kg) in plant tissues was modeled using two-factor multiple linear regression. The results showed that the selected input variables were supportive to develop prediction models with higher linear regression (R2 > 0.72), high model efficiency (ME: 0.92–0.99), low mean average normalizing error (MANE < 0.02), and statistically significant F > Prob values. Kruskal-Wallis one-way post hoc test indicated that the contents of Cd, Cu, Fe, Pb, and Zn in the roots, leaves, and whole plant were affected by PME concentration while the contents of Mn did not. The correlation studies showed that the bioaccumulation of heavy metals was found both element and PME concentration specific. This work represents an effective method to model heavy metal uptake by P. stratiotes from PME. Furthermore, this methodology can also be adopted for predicting effective metal uptake by plant species being used for the phytoremediation of heavy metals from industrial effluents. [ABSTRACT FROM AUTHOR]

Abstract Pulp and paper industry is one of the high priority sectors that generates large amount of solid (sludge) and liquid (paper mill effluent) wastes. Making use of this huge quantity of paper mill sludge (PMS) in an environment friendly manner is challenging and cost involving. Similarly the present wastewater treatment strategies based on physical and chemical methods encounter certain serious setbacks including secondary pollution generation with expensive mode of abatement processes. The present study aims at a "waste treats waste" strategy for the bioremediation of paper mill effluent in fluidized bed reactor (FBR) using another waste of the same industry, PMS as immobilizing matrix for Planococcus sp. TRC1, a wastewater bacterial isolate. This study simultaneously explores this isolate for the yellowish orange pigment it produces (2.3 ± 0.2 mg/gm of dry bacterial biomass) and characterizes it as a member of the pharmacologically important carotenoid pigment family via UV-Vis spectrophotometry, TLC, FT-IR and 13C NMR. The antioxidant potential of this pigment was studied by DPPH assay (IC 50 = 33 ± 0.4 μg/ml) and H 2 O 2 assay (IC 50 = 147.4 ± 2.2 μg/ml). In FBR, the PMS immobilized bacteria showed removal of phenol, lignin, colour and COD from the effluent by 96%, 74%, 81% and 85% respectively after 60hr of treatment. The experimental data on immobilization fitted well with pseudo second-order (R2 = 0.955) and Freundlich adsorption isotherm (R2 = 0.996) models. The alterations in PMS before and after bacterial immobilization, as revealed by SEM and FT-IR, depicted the success of PMS as immobilization matrix. Phytotoxicity (90% seed germination) and mutagenicity studies confirmed that the treated effluent was substantially less toxic than its raw state. This study highlights a novel utilization possibility of PMS in an eco-friendly and economic way as immobilization matrix for Planococcus sp.TRC1 for paper pulp mill effluent treatment along with production of carotenoid pigment from this potential bacterial isolate as value added product. Graphical abstract Image 1 Highlights • Carotenoid production and abatement of paper pulp mill effluent by Planococcus sp.TRC1 was studied. • Paper mill sludge (PMS) was characterized for immobilizing the bacteria to be used in fluidized bed reactor. • Reusability of PMS and scale up possibility was described. • Toxicity studies revealed reduced phytotoxicity and mutagenicity of the effluent by this approach. [ABSTRACT FROM AUTHOR]

In this study, membrane fouling caused by paperboard mill treated effluent (PMTE) was investigated based on a dead-end ultrafiltration (UF) pilot-scale study. The membranes employed were commercial hydrophobic UF membranes made of polyethersulfone (PES) with a molecular weight cut-off of 10 kDa, 50 kDa, and 100 kDa. Membrane fouling mechanism during dead-end filtration, chemical analysis, field emission scanning electron microscopy (FESEM), energy-dispersive spectrophotometry (EDS), attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy and 3D fluorescence excitation−emission matrix (3DEEM) analysis were applied to understand which fraction of the dissolved and colloidal substances (DCS) caused the membrane fouling. The results indicated that the phenomenon controlling fouling mechanism tended to be cake layer formation (R2 ≥ 0.98) for all membranes tested. The 3DEEM results indicate that the majority of the organic foulants with fluorescence characteristics on the membrane were colloidal proteins (protein-like substances I+II) and macromolecular proteins (soluble microbial products, SMP-like substances). In addition, polysaccharide (cellulosic species), fatty and resin acid substances were identified on the fouled membrane by the ATR−FTIR analysis and play an important role in membrane fouling. In addition, the FESEM and EDS analyses indicate that the presence of inorganic foulants on the membrane surfaces, such as metal ions and especially Ca2+, can accelerate membrane fouling, whereas Mg and Si are linked to reversible fouling.

This study was focused on removal of various parameters in paper mill effluent using a method called bioremediation by Azolla caroliniana. The experimental investigations have been carried out using Azolla caroliniana for conducting the sorption study with various dilution ratios (2, 4, 6, 8, and 10), pH (3, 4, 5, 6, 7, 8 and 9) and biomass (200, 400, 600, 800 and 1000 g). The maximum removal percentage of TDS, BOD and COD in a paper mill effluent was obtained at the optimum dilution ratio of 6, pH of 8 and biomass of 800 g. The results of this study indicated that the maximum removal percentage of TDS, BOD and COD in a paper mill effluent was 82.3 %, 88.6 % and 79.1 % respectively. Also, the study focused on uptake of TDS, BOD and COD in paper mill effluent by Azolla caroliniana through bioaccumulation factor and translocation factor. The results of bioaccumulation factor revealed that TDS, BOD and COD in paper mill effluent were adsorbed by Azolla caroliniana. The results of translocation factor revealed that the roots of Azolla caroliniana translocate the TDS, BOD and COD in a paper mill effluent to the shoots of Azolla caroliniana. From the results, this study concluded that bioremediation by Azolla caroliniana could be effectively used for removing TDS, BOD and COD in a paper mill effluent. This study also suggested that Azolla caroliniana may be used for removing various contaminants, not only from paper mill effluent, but also from any other industrial effluents.

Suaeda maritima is a halophyte that has been evolutionary adapted to cope with saline and heavy metal conditions. The aim of the present study was to examine the biochemical response of Suaeda maritima against phytoextracting heavy metals and salts from paper mill effluent. Suaeda maritima seedlings have been grown for 120 days with an irrigation solution of 250 ml of 75% raw paper mill effluent after four drenching. Analysis of biochemical parameters revealed that maximum synthesis of chlorophyll, protein, phenol, proline and glycinebetaine may be involved in their ability to cope with heavy metal and salt stress. The present study confirms that the accumulation and increase of biochemical constituents can be considered as an efficient ROS scavenger and also maintain cellular homeostasis and metabolic functions in photosynthetically active leaves in Suaeda maritima, during phytoextraction studies. [ABSTRACT FROM AUTHOR]

Laboratory experiments were carried out to assess the phytoremediation potential of water hyacinth (Eichhornia crassipes [Mart.] Solms) for the removal of different parameters of the paper mill effluent. The maximum removal efficiency of E. crassipes and phytokinetic removal rate were recorded at 50% concentration of the paper mill effluent followed by 60 days of phytoremediation experiments. The most percent reduction was observed in the contents of electrical conductivity (EC; 62.23%), total dissolved solid (TDS; 72.54%), biochemical oxygen demand (BOD; 79.93%), chemical oxygen demand (COD; 85.66%), total Kjeldhal nitrogen (TKN; 89.27%), P (72.39%), Ca2+ (51.79%), Mg2+(51.02%), Na+ (57.10%) and K+(71.47%) and phytokinetic removal rate in the subjects of EC (0.00011 mg l−1d−1), TDS (0.045 mg l−1d−1), BOD (0.0314 mg l−1d−1), COD (0.0461 mg l−1d−1), TKN (0.0034 mg l−1d−1), P (0.0050 mg l−1d−1), Ca2+ (0.0045 mg l−1d−1), Mg2+ (0.003 mg l−1d−1), Na+ (0.004 mg l−1d−1) and K+ (0.004 mg l−1d−1) after phytoremediation at 60 days. The maximum plant height (120.73 cm), fresh plant biomass (383.54 ± 0.15 gkg−1) and total chlorophyll content (3.74 ± 0.05 mgg−1 fwt), crude protein (19.11 mg 100 g−1 fwt), crude fiber (29.92 mg 100 g−1 fwt), total carbohydrate (35.22 mg 100 g−1 fwt) and total ash (26.88 mg 100 g−1 fwt) of E. crassipes were observed with 50% concentration of the paper mill effluent at 60 days of phytoremediation experiments. The maximum relative growth rate (13.86 gg−1 d−1) of E. crassipes was detected with 50% concentration of paper mill effluent at 60 days of phytoremediation experiments. Therefore, E. crassipes was recorded to be feasible for the removal of different pollutants of paper mill effluent, responsible for the eutrophication of the aquatic resources. [ABSTRACT FROM AUTHOR]

In this study, Moringa oleifera ( M. oleifera ) performance as an eco-friendly coagulant in the enhanced primary treatment of paper mill effluent was investigated. Its performance in terms of turbidity removal and COD abatement was examined. Local M. oleifera seed powder from ADRAR-city, South of Algeria, was used. Conventional jar tests were conducted for enhancing the primary treatment of paper mill effluent from paper factory. For this reason, comparative coagulation tests were performed using aluminum sulfate (alum). Indeed, in terms of turbidity abatement, 96.02% and 97.1% were obtained for Moringa and alum, respectively. However, in the case of COD abatement, the abatement rate of M. oleifera seeds was slightly higher than that of alum, 97.28% and 92.67%, respectively. Because M. oleifera is a natural resource that is locally available, an eco-friendly coagulant, non-toxic, and biodegradable and does not affect the pH of water; thus, its use allows to avoid numerous disadvantages of conventional coagulants like alum. [ABSTRACT FROM AUTHOR]

A laboratory study was conducted to assess the performance of a Hybrid Upflow Anaerobic Sludge Blanket (HUASB) Reactor in order to treat the effluent from a paper mill. The maximum organic loading rate (OLR) is 12 kg COD/m3.day. The OLR was calculated on the basis of COD inlet in the reactor for different flow rates. A hydraulic retention time (HRT) of 12 hrs was maintained in the reactor. The maximum TCOD and SCOD reduction was 92% and 88% respectively. The maximum biogas production was 3.27 m3/m3.day. Development of granulation with two different inoculums in early start-up was also studied. The study revealed that earlier start-up and granulation of biomass could be achieved using mixed sludge (cow dung and effective microorganisms). Scanning Electron Microscope (SEM) study of the granules showed predominance of Methanosarcina and Methanothrix type of species on the surface of granules. The process efficiency and biogas production were found to be increased with an increase in the organic loading rate. The size of the granules was 1-3 mm and exhibited good settling tendency. [ABSTRACT FROM AUTHOR]

[Display omitted] • Evaluation of dark fermentative hydrogen production using paper mill effluent (PME) • Investigation of the impact of different HRTs on the biofilm reactor performance. • H 2 production rate was enhanced to 6.21 L H 2 d−1 L−1 by decreasing HRT to 2 h. • Max. yield of H 2 was 0.96 mmol H 2 g−1 COD at 8 h HRT. • Production of VFAs as valuable by-products as well as COD removal. This study assessed the feasibility of continuous hydrogen production in an anaerobic packed bed biofilm reactor (APBR) using paper mill effluent (PME) without any pretreatment or modification. To form a microbial biofilm on supports, the reactor was seeded with a thermal pretreated anaerobic sludge. After the start-up stage, under mesophilic conditions and pH control, the system performance in the case of hydrogen production as biofuel and VFAs as valuable by-products as well as COD removal was investigated at different hydraulic retention times (HRTs) (24, 16, 12, 8, 4, 2 and 1.2 h). The highest hydrogen concentration in the produced gas was 41.5 % obtained at HRT 4 h. The highest hydrogen production rate and yield were 6.21 L H 2 d−1 L−1 at HRT 2 h and 0.96 mmol H 2 g−1 COD at HRT 8 h, respectively. With decreasing the HRT from 24 to 1.2 h, the OLR was increased from 27.35 to 547 g COD L−1 d−1 that positively affect the hydrogen production rate for all HRTs except for the shortest HRT. Furthermore, COD removal efficiency was reduced from 25.2 to 6 %. Low value of COD removal efficiency is because of conversion of organic inlet to valuable metabolites such as VFAs in the effluent. [ABSTRACT FROM AUTHOR]

This work reports the details of the design components and materials used in a linear compound parabolic trough reactor constructed with an aim to use the photocatalyst for solar photocatalytic applications. A compound parabolic trough reactor has been designed and engineered to exploit both UV and visible part of the solar irradiation. The developed compound parabolic trough reactor could receive almost 88% of UV radiation along with a major part of visible radiation. The performance of the reactor has been evaluated in terms of degradation of a probe pollutant using the parameters such as rate constant, residence time and photonic efficiency. An attempt has been made to assess the performance in different ranges of solar spectrum. Finally the developed reactor has been employed for the photocatalytic treatment of a paper mill effluent using Degussa P25 as the photocatalyst. The paper mill effluent collected from Nagaon paper mill, Assam, India has been treated under both batch mode and continuous mode using Degussa P25 photocatalyst under artificial and natural solar radiation, respectively. The photocatalytic degradation kinetics of the paper mill effluent has been determined using the reduction in total organic carbon (TOC) values of the effluent. [ABSTRACT FROM AUTHOR]

The optimization of water management in industrial processes is paramount in diminishing or mitigating, as far as possible, the negative externalities generated by its current use within the linear economy model. This research presents methods for the optimization of wastewater from paper mills which are associated with the new sustainability and circular economy model. In this way, the concept of circular economy was applied to the wastewater treatment from a paper mill, with the objective of recovering the resources contained in this type of effluent. The wastewater treatment plant is based on a biological reactor of activated sludge, and treats a flow of 4868 m3·day−1. This study proposes the development and evaluation of indicators of circular economy applied to wastewater from a paper mill, as well as the assessment of the removal performance of color, total suspended solids (TSS), biochemical oxygen demand on the fifth day (BOD5), and chemical oxygen demand (COD), which are higher than 96% in all cases. Per 1 m3 of wastewater from a paper mill, a volume of 0.9 m3 of potentially reusable water and a recovered sludge mass of 0.7 kg are generated; the latter is reused as a mineral filler during the process itself. In light of this, a multivariable statistical analysis was applied to determine the relationship of the operation variables and indicators of circular economy. In this way, wastewater from the paper mill can be regarded as a technological nutrient, which is partially reintroduced into the production process, enabling the recovery of the water and mineral fillers that it contains.

The fishes, Rasbora daniconius were exposed to lethal concentration at 9.5% (LC50 of 96 hrs) for 96 hrs and sublethal concentrations [1.9 % (1/5) and 0.95 % (1/10) LC50 of 96hrs] of paper mill effluent, for 30 days to study the impacts on the histology of gill. Many pathological changes were observed in the gill lamellae such as bulging at the tip of primary lamellae, epithelial hypertrophy, Fusion, curling, reduction in secondary gill lamellae, disorganization and rupture in secondary lamellae, swelling in pillar, mucous, and chloride cells. Hemorrhage at the primary and secondary lamellae.

Two fungi (unidentified) were isolated from soil and marine environ-ments. These isolates were used for bioremediation of pulp and paper mill effluent at the laboratory scale. The treatment resulted in the reduction of color, lignin, and COD of the effluent in the order of 78.6%, 79.0%, and 89.4% in 21 days. A major part of reductions in these parameters occurred within 5 days of the treatment, which was also characterized by a steep decline in the pH of the effluent. The enzyme activity of these fungi was also tested, and the clearance zone was obtained in the plate assay.

A comparative pot experiment was conducted in 2014 to study heavy metal contamination in soil and bioaccumulation in leaves and roots of Spinacia oleracea (spinach) on irrigation with paper mill effluent (PME). Study revealed that there was significant increase in the content of copper (Cu, +81.62 %) at (P<1%), iron (Fe, +79.62 %), zinc (Zn, +90.73 %), cadmium (Cd, +98.99 %), lead (Pb, +95.91 %), nickel (Ni, +98.40 %), chromium (Cr, +97.54 %) at (P<0.1%) in the soil irrigated with PME as compared to soil irrigated with pond water (PW) (control). Increasing PME doses from 10 % (10 % PME + 90 % PW) up to 80 % (80 % PME + 20 % PW) caused a progressive increase in the accumulation of metals, i.e. Fe, Zn, Cd, Cu, Pb, Ni and Cr in the roots and leaves of S. oleracea. The metals accumulated in the plant parts (root and leaves) of S. oleracea showed significant (p<5%) and a positive correlation with different concentrations of PME. Among various metallic concentrations high values of heavy metals such as Fe (10.97±0.02 mg/kg), Zn (8.45±0.10 mg/kg), Cd (7.63±0.08 mg/kg), Cu (12.12±0.09 mg/kg), Pb (6.47±0.04 mg/kg), Ni (8.48±0.10 mg/kg), and Cr (5.81±0.02 mg/kg) were found in roots compared to Fe (9.58±0.06 mg/kg), Zn (6.68±0.06 mg/kg), Cd (5.67±0.01 mg/kg), Cu (10.30±0.11 mg/kg), Pb (4.83±0.03 mg/kg), Ni (6.84±0.02 mg/kg) and Cr (4.50±0.09 mg/kg) in leaves of S. oleracea irrigated with 80 % (80 % PME + 20 % PW) dose. Thus, the practice of using undiluted PME as agro-based organic fertilizer for irrigation increased the concentration of heavy metals which were accumulated in S. oleracea, posing a potential threat to human health from this practice of irrigation. Therefore, proper dilution of PME appears to be necessary for irrigation purpose for the minimum accumulation of heavy metals in soil and plants. [ABSTRACT FROM AUTHOR]

Recently, researchers working with aerated bioreactors identified a different microbial organization in the form of aerobic granules. In this configuration, bacteria clump together more tightly than conventional floc, which reduces biofilm formation on the membrane surface of membrane bioreactors and allows higher flux for longer time periods during filtration. This study examined the possible formation of aerobic granules treating paper mill effluent and compared the removal efficiency of organic matter from granular with the conventional flocculent sludge. The filterability of both types of sludge was also compared. Two reactors were operated in parallel with aerobic granular and flocculent sludge. Both systems achieved very high Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD)-removal efficiencies. Sludge filtration tests showed a higher critical flux for granular sludge with total suspended solids (TSS) equal to 2,700 mg L−1. However, the opposite behavior was observed when the reactors were operated with a TSS value of 4,400 mg L−1. [ABSTRACT FROM PUBLISHER]

Due to high pollution load and colour contributing substances, pulp and paper mill effluents cause serious aquatic and soil pollution. A lignin-degrading bacterial strain capable of decolourising Azure-B dye was identified as lignin peroxidase (LiP) producing strain LD-5. The strain was isolated from pulp and paper mill effluent contaminated site. Biochemical and 16S rDNA gene sequence analysis suggested that strain LD-5 belonged to the Serratia liquefaciens . The strain LD-5 effectively reduced pollution parameters (colour 72%, lignin 58%, COD 85% and phenol 95%) of real effluent after 144 h of treatment at 30 °C, pH 7.6 and 120 rpm. Extracellular LiP produced by S. liquefaciens during effluent decolourisation was purified to homogeneity using ammonium sulfate (AMS) precipitation and DEAE cellulose column chromatography. The molecular weight of the purified lignin peroxidase was estimated to be ∼28 kDa. Optimum pH and temperature for purified lignin peroxidase activity were determined as pH 6.0 and 40 °C, respectively. Detoxified effluent was evaluated for residual toxicity by alkaline single cell (comet) gel electrophoresis (SCGE) assay using Saccharomyces cerevisiae MTCC 36 as model organism. The toxicity reduction to treated effluent was 49.4%. These findings suggest significant potential of S. liquefaciens for bioremediation of pulp and paper mill effluent. [ABSTRACT FROM AUTHOR]

In paper processes, the variability of effluent composition and flow is impossible to predict and generally depends on the type of production method used and the manufacturing breakdowns suffered. Wastewater treatment plant operators find it difficult to maintain the efficiency of biological treatment processes. This paper focuses on activated sludge treatment modelling of paper mill wastewater to provide operators with additional support. Based on both standard activated sludge models (ASM) and those specific to pulp and paper, a number of relevant modifications are put forward so as to easily identify model parameters and obtain a validated model from the dynamic data available. Model validation is performed at a pilot plant fed with industrial effluent. Dynamic steps are applied to the process inputs (flow rates and concentrations), which induces dynamic behaviour in the biological reactor. Measurement uncertainties are taken into account in both the identification and validation steps, while the confidence ranges for the parameters identified are estimated. Significant biological activity is indicated by the high values obtained for the parameters identified, which is confirmed by model validation. Because the size of the pilot plant is sufficient to reproduce realistic hydrodynamics, the validated model accurately describes a treatment plant's behaviour and can be used by operators as a decision-support tool. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate the toxic impact of wastewater from sites 1 and 2 of Tung Dhab drain in the state of Punjab, India, on fish behaviour, morphology and gill histopathological biomarkers in comparison to control group. Static non-renewal tests were conducted for 96 h to determine LC50 of the wastewater for both sites using five concentrations (6.25-100 %). Fish were regularly noticed for any deviation in behaviour and external morphology. Physico-chemical analysis of wastewater was done using standard methods recommended by APHA/AWWA/WEF (). Chronic toxicity tests were conducted for 15 and 30 days with sublethal concentrations of wastewater (50-90 % of LC50) and gill histopathology was assessed. Wastewater near a paper mill was more toxic as observed from LC50 values of 72.45 %. There was evident deterioration of water quality as the recorded values of some parameters were higher than the standard discharge limits. The test fish exhibited increased air gulping and surfacing, erratic movements initially and decreased opercular movements as the exposure period increased. Morphological observations include increased body colouration, mucus secretion, scale loss and haemorrhages on the skin and lower lip. Alterations in the gill histology such as complete lamellar fusion, epithelial lifting and intraepithelial oedema, haemorrhages, lamellar necrosis and aneurysm were noted in the test fish. Results demonstrate that the fish exposed to wastewater from both sites showed significantly greater change in gill organ index (I) as compared to control fish for 15 and 30 days. [ABSTRACT FROM AUTHOR]

Present study relates to the corrosivity of paper mill effluent and corrosion performance of stainless steel (SS) as a construction material for the effluent treatment plant (ETP). Accordingly, immersion test and electrochemical polarization tests were performed on SS 304 L, 316 L and duplex 2205 in paper mill effluent and synthetic effluent. This paper presents electrochemical polarization measurements, performed for the first time to the best of the authors' information, to see the influence of chlorophenols on the corrosivity of effluents. The corrosivity of the effluent was observed to increase with the decrease in pH and increase in Cl−content while the addition oftends to inhibit corrosion. Mill effluent was found to be more corrosive as compared to synthetic effluent and has been attributed to the presence of various chlorophenols. Corrosion performance of SS was observed to govern by the presence of Cr, Mo and N contents. [ABSTRACT FROM PUBLISHER]

The present study was carried out for the treatment of paper mill effluent using combination of activated sludge process and membrane separation. An integrated paper mill employing OCEHH sequence (oxidation, chlorination, alkali extraction re-enforced by oxygen and peroxide, hypo-1, and hypo-2) for the bleaching of hardwood pulp was selected for the study. The purpose of this work was to examine the water quality and membrane performance when combining activated sludge process with different membrane separation processes in series. Pollutant removal including adsorbable organic halides (AOX) was compared among different treatment combinations; (i) ASP + microfiltration (MF), (ii) ASP +MF + ultrafiltration (UF), (iii) ASP +MF + UF + nanofiltration (NF), and (iv) ASP +MF + UF + NF + reverse osmosis (RO) to select the optimal treatment scheme for water recycling in the paper mill. Different initial inlet pressures were used for the UF and NF (6.8, 10.3, and 13.7 bar) and for RO (10.3, 13.7, and 17.2) The retentate from each membrane was recycled back to the feed and retreated until the inlet pressure increased to the maximum cut-off pressure for each membrane. After separation, 100 % total suspended solids, total dissolved solids, color removal and 94.2 % chemical oxygen demand, and 86 % AOX removal was observed. This study suggests the potential application of the combination of membrane separation with activated sludge process for recycling water in the paper industry. [ABSTRACT FROM AUTHOR]

The in vitro potential of sensitizers and related compounds (SRCs) originating from impurities in waste paper in activating the human aryl hydrocarbon receptor (AhR) α was assessed using yeast reporter gene as well as cytochrome P450 (CYP)1A1 and ethoxyresorufin O-deethylase (EROD) assays. In the yeast assay, eight compounds exhibited agonist activity, and their activity relative to β-naphthoflavone (BNF) ranged from 1.4 x 10-4 to 8.3 x 10- 2, with the highest activity observed for benzyl 2-naphthyl ether (BNE). In the EROD assay, six compounds caused a more significant induction of CYP1A-dependent activity than did the vehicle control at 50 µM (p < 0.01), and their induction levels were 5.1- to 11-fold more potent; 1,2-bis(3-methylphenoxy)ethane (BME) was the most effective inducer. The water from the waste paper recycling area was fractioned using solid-phase extraction (SPE) combined with a C18 disk and florisil cartridge. In gas chromatography-mass spectrometry (GC-MS) analysis, SRCs were detected in the first fraction, at a total concentration of 5.5 µg/L. This fraction also activated AhR, and its activity, expressed as a BNF equivalent value, was 0.42 nM in the yeast assay. The contribution ratio of active compounds accounted for up to 34% and 4.4% observed activity of the fraction and total samples, respectively. To our knowledge, this is the first study to show that paper industry-related compounds, namely aromatic sensitizers, activate AhR by using a yeast assay and HepG2 cells. [ABSTRACT FROM AUTHOR]

The potential of agrobased paper mill effluent (PME) as ferti-irrigant was assessed. Ferti-irrigation responses to 5, 10, 25, 50, 75, and 100% of PME doses onPhaseolus vulgarisL., cv. Annapurna, in the rainy and summer seasons were investigated. The fertigant concentrations produced changes in electrical conductivity (EC), pH, organic carbon (OC), sodium (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), total Kjeldahl nitrogen (TKN), phosphate (PO43–), sulfate (SO42–), iron (Fe2+), cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), and zinc (Zn) of the soil in both seasons. The agronomic performances ofP. vulgarisincreased from 5 to 25% in both seasons compared to controls. The accumulation of metals increased in soil andP. vulgarisfrom 5 to 100% PME concentrations in both seasons. The contamination factor (Cf) of various metals was in order of Cr > Mn > Cu > Cd > Zn for soil and Mn > Zn > Cu > Cd > Cr forP. vulgarisin both seasons after fertigation with PME. Therefore, PME can be used to improve the soil fertility and yield ofP. vulgarisafter appropriate dilution. [ABSTRACT FROM PUBLISHER]

Released effluent form paper mill percolates though soil and slowly mixes with ground water aquifers. Water samples were collected from 5 sampling stations (S1, S2, S3, S4, S5) around the paper mill. Samples were analyzed for their water quality for various parameters. Statistical analysis was employed to evaluate the water quality for 5 monitoring stations. Water quality variables such as, TDS, Sulphate, Chloride exceeded WHO guidelines of drinking water. The pollution threat to ground water is from TDS, Sulphate and Chlorides, which are associated with pulp waste in the studied area. The study reveals that wastewater even from a single mill can affect the ground water quality of nearby area. [ABSTRACT FROM AUTHOR]

Objective: The objective of the present study was to isolate a potential and novel Bacillus strain from paper mill effluent for the production of an industrially important xylanase. Material and Methods: A potent xylanase producing microorganism was isolated from paper mill effluent based on zone of clearance on xylan agar medium. The strain was identified based on 16S rRNA analysis and biochemical characterization. Xylanase produced by the isolated strain was partially purified and characterized for its activity and stability. Results: The xylanase produced by this Bacillus aerophilus KGJ2 was thermophilic, shows higher activity and stability at 70°C. Xylanase had activity peak at pH 4.0 and was very acid stable. Birchwood xylan and beef extract were identified as best suited carbon source and nitrogen source, respectively. Conclusion: The results confirm that Bacillus aerophilus KGJ2 produced a unique acidothermotolerant xylanase. [ABSTRACT FROM AUTHOR]

Highlights: [•] CNTs have offered higher hydrophilicity to PES/f-MWCNTs nanocomposite membranes. [•] PES/f-MWCNTs membranes showed good rejection capability. [•] Rejection efficiency has improved without compromising the permeability. [Copyright &y& Elsevier]

The present study report physiochemical properties of paper mill effluent and fungal diversity present in effluent. The fungi were further studied for production of organic waste degrading enzymes. Water quality analyzer, turbiditymeter and spectroquant nova 60 and titration method were used to physiochemical properties of paper mill effluent. Fungi were isolated from effluent in agar plate. Organic waste degrading amylolytic and cellulolytic enzyme produce by fungi were recorded in agar plate. The mean value of different physiochemical properties were found as follows: pH 7.50, EC 4.26 mS, TSS 0.28 mg/L, TDS 436.4 mg/L, Turbidity 145.26 NTU, DO 4.48 mg/l, BOD 48.26 mg/L, COD 54.14 mg/L, fluoride 1.15 mg/L, lead 1.78 mg/L and iron 0.51 mg/L. Aspergillus niger, A. fumigates and Penicillium oxalicum were found as dominant species. Fungi isolated from paper mill effluent produced enzymes to degrade the organic waste substances. [ABSTRACT FROM AUTHOR]

The JK Paper industry located at Rayagada discharges biologically untreated effluent more than the permissible limit prescribed by Pollution Control Board, Odisha in to the environment. The industry is seriously polluting the surrounding aquatic and terrestrial environment. No detailed intensive study was carried out by previous workers on this industry earlier. The present study aims at finding out the impact of effluent on the flora at the contaminated site. The chemically treated effluent (TE) contained significant amount of mercury and cadmium. The TE has high BOD, COD, dissolved solids and suspended solids when compared to normal river water at the site of discharge. The TE deteriorated the natural water bodies changing the physico-chemical properties of natural river water. After meeting the river water the TE was diluted after 1 km distance from the meeting point of the river. Crop plants collected from the contaminated site showed higher level of residual Hg and Cd and significant depletion in pigment was observed. Plants collected from both the sides of the treated effluent canal showed significant amount residue mercury and cadmium in the plant leaves. The plants exposed to the TE, showed variation in chlorophyll and Phaeophytin pigment content when compared to their respective control values in all terrestrial plants collected from the contaminated site. In some plant leaves little increment in the pigment level was noted but the values were not significant. The changes observed in the plant pigment might be due to heavy metal accumulation. The presence of residual Hg and Cd in crop plants and plant leaves grazed by grazing animals after absorption, accumulation and enrichment may lead to a possible biological magnification, warrants attention. Proper biological treatment, treatment of effluent by modern methods and removal of heavy metals from the effluent before discharge by the industry is suggested. • Biological treatment of the effluent was not carried out by the industry & chemicals present in the effluent were significantly high.. • The water quality of the river water deteriorated due to the discharge of effluent of the paper mill. • Plants collected from the contaminated site showed significant accumulation of cadmium and mercury in leaf tissues • Significant depletion in pigment content of exposed plant leaves was noticed. • Depletion in plant pigment was due to accumulation of cadmium and mercury in plant tissues absorbed from the effluent. [ABSTRACT FROM AUTHOR]

In the present study, plant-scale process integration was applied to an Indian paper mill using the water cascade analysis (WCA) technique. Three limiting constraints, chemical oxygen demand (COD), total dissolved solids (TDS), and adsorbable organic halides (AOX), were considered for the study. A nearest neighbor algorithm was used to distribute the freshwater and recycled water among the plant operations. It was found that the limiting critical constraint depends upon the types of processes and streams involved in the integration. The limiting critical constraint can differ for different sections of the same industry, and can differ in different schemes of integration. After process integration, a 55.6% reduction in effluent flow, a 36% reduction in COD, and a 73% reduction in AOX were observed. After process integration, a 35.21% reduction in pollution costs can be achieved and, assuming the average production of the mill to be 225 tons per day, a savings of Indian rupees (INR) 1.73 per kg of paper produced can be achieved by employing process integration. The water cess was calculated as INR 3024.77 per day without integration for the sections that were considered for integration, while after integration, a 41.53% savings in the form of water cess was calculated. [Copyright &y& Elsevier]

The present investigation aims to assess the phytoremediation potential of six aquatic macrophytes, viz. Eichhornia crassipes, Hydrilla verticillata, Jussiaea repens, Lemna minor, Pistia stratiotes and Trapa natans grown in paper mill effluent of JK Paper mill of Rayagada, Orissa, for remediation of heavy metals. The experiment was designed in pot culture experiments. Assessment of physico-chemical parameters of paper mill effluent showed significant decrease in pH, conductivity, total dissolved solids, total suspended solids, chlorine, sulphur, biological and chemical oxygen demand after growth of macrophytes for 20 days. Phytoremediation ability of these aquatic macrophytic species for copper (Cu) and mercury (Hg) was indicated by assessing the decrease in the levels of heavy metals from effluent water. Maximum reduction (66.5 %) in Hg content of untreated paper mill effluent was observed using L. minor followed by T. natans (64.8 %). L. minor showed highest reduction (71.4 %) of Cu content from effluent water followed by E. crassipes (63.6 %). Phytoextraction potential of L. minor was remarkable for Hg and Cu, and bioaccumulation was evident from bioconcentration factor values, i.e. 0.59 and 0.70, respectively. The present phytoremediation approach was considered more effective than conventional chemical treatment method for removing toxic contaminants from paper mill effluent. [ABSTRACT FROM AUTHOR]