Pulp Effluent Research Articles

Hemp derived activated carbon supported nanoscale zero–valent iron as a heterogeneous Fenton catalyst for the treatment of pulping effluent

Activated carbon (AC) and nanoscale zero–valent iron (nZVI) have been widely used in wastewater treatment, respectively, for the removal of organics. In this study, hemp fibers were applied to prepare AC by phosphoric acid activation at a carbonization temperature of 400°C. Then nZVI particles were immobilized onto the surface of hemp derived AC (HAC), and the composites (nZVI@HAC) were used as heterogeneous catalysts for Fenton–like treatment of pulping effluent. The as–prepared catalysts were characterized. The optimum conditions for Fenton–like reaction and the reusability of catalyst were investigated. Results showed that nZVI particles were well distributed on the surface of HAC without aggregation. Both HAC and nZVI@HAC have microporous structure. With the loading of nZVI, the catalysts were endowed with magnetism and more active sites. Under the optimal conditions (initial pH 3.0, H2O2 35 mmol/L, 2–nZVI@HAC 3.0 g/L), COD removal rate reached 87.74% of the highest. This work illustrated that the feasibility of HAC as a carrier of nZVI, and nZVI@HAC was an effective heterogeneous Fenton catalyst.

Microbiological evaluation of nano-Fe3O4/GO enhanced the micro-aerobic activate sludge system for the treatment of mid-stage pulping effluent

Nano-Fe3O4/graphene oxide (MGO) was composited and applied to the micro-aerobic sludge for the treatment of the mid-stage pulping effluent, eliminating the adverse effect of using the single nano-Fe3O4 and GO. Effects of MGO on treatment efficiency, sludge physicochemical performance, microbial community during the acclimation process and electron transport activity were studied. The results indicated that CODCr removal rate, flocculating performance and settleability of the sludge were obviously promoted by the addition of MGO compared to that of blank, GO and Fe3O4. The presence of MGO conduced to form a stable co-metabolic microbial community and enhance the electron transfer activity.

Evaluation of aerated lagoon modified with spongy support medium treating Kraft pulp mill effluent

The pulp industry generates high effluent flows, which contain high chemical oxygen demand (COD), biochemical oxygen demand (BOD5), colour and ecotoxicity. This study aimed to evaluate the treatment of Kraft pulp effluent by aerated lagoon modified with sponge support media (APG). It was assessed the arrangement of the support media in the aerated lagoons in the organic load rate (OLR) of 0.2 kgCOD m-3 d-1, and after that, with OLR variation from 0.2 to 1.2 kgCOD m-3 d-1. The parameters evaluated were BOD5, COD, colour, lignin derivatives, total phenolic compounds and acute ecotoxicity in D. magna. COD and BOD5 removals were 32% and 88%, respectively, for free and confined support media in 0.2 kgCOD m-3 d-1. There was no colour or total phenolic compounds removal under these conditions. Considering the treatment in which there was a variation of the organic load rate, 1.2 kgCOD m-3 d-1 had the best performance. In this case, 50% and 75% of COD and BOD5 were removed, respectively. Removal of colour, total phenolic compounds and lignin derivatives were around 20%, 18% and 10%, respectively. The acute ecotoxicity was reduced to toxicity factor equal to 1 in all treatments. Comparing the aerated lagoon modified systems with those without the APG, it was suggested to apply spongy support in higher organic load rate than these typically used in aerated lagoons.

Isolation of Cellulolytic Actinomycetes from Soil and its Potent Application in Decolorization of Paper and Pulp Effluent

Isolation of Cellulolytic Actinomycetes from Soil and its Potent Application in Decolorization of Paper and Pulp Effluent

Effect of Hot-Pressing Temperature on Characteristics of Straw-Based Binderless Fiberboards with Pulping Effluent.

This study aimed to improve straw-based fiberboard properties without resins by adding pulping effluent as well as to investigate the difference among boards under variable hot-pressing temperatures. The characterization of fiberboards produced from wheat straw under pressing temperatures ranging from 160 to 200 °C was first described. The surface appearance, surface chemistry, thermal transitions, and mechanical performance of the boards were evaluated to investigate the effect of varying hot-pressing temperature. The results indicated that the surface color of boards became darker when the temperature was above 190 °C. Additionally, Fourier transform infrared (FT-IR) measurements showed that more low-molecular constituents and hydrogen bonds were produced under higher pressing temperatures. Furthermore, the physical and mechanical property data were analyzed statistically using one-way analysis of variance (ANOVA) and Tukey’s tests (α = 0.05). The results demonstrated that straw-based fiberboards with effluent under 190 °C exhibited superior strength and water resistance capacities, and showed great potential in commercial decorating and packaging applications.

English

English

Optimization of Cultural Conditions for the Treatment of Pulp and Paper Industrial Effluent by Pleurotus ostreatus (L.)

Optimization of Cultural Conditions for the Treatment of Pulp and Paper Industrial Effluent by Pleurotus ostreatus (L.)

Fe/C micro electrolysis and Fenton oxidation process for the removal of recalcitrant colored pollutants from mid-stage pulping effluent

The pulp and paper industry produces a large amount of colored effluent in the pulping, bleaching, and papermaking processes. The wastewater from the pulp washing and bleaching stages is also known as mid-stage pulping effluent, which is difficult to treat due to its toxicity and dark dolor. This paper reports a novel Fe/C micro-electrolysis process for the treatment of the mid-stage pulping effluent. Results show that this process is effective in removing the color under optimal reaction conditions. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analyses indicate that the colored pollutants were removed from the wastewater in the Fe/C micro-electrolysis by adsorption, collection and filtration mechanisms. The Fe 2+ ions produced in the micro-electrolysis process functioned as Fenton’s reagents with H 2 O 2 in the follow-up oxidation stage, which enhanced the removal of chemical oxygen demand (COD) and color.

Extraction of ligninolytic enzymes from novel Klebsiella pneumoniae strains and its application in wastewater treatment

The presence of lignin and its derivatives in pulp effluent increases the pollution load on the environment. With an aim of better degradation and decolourization of wastewater, this study proposes the utilization of different ligninolytic enzymes from novel bacterial strains. Four novel bacterial strains of Klebsiellapneumoniae (K. pneumoniae strains NITW715076, NITW715076_1, NITW715076_2 and NITW715076_3) were isolated and identified. The ligninolytic enzymes were characterized by plate assay method. For the optimization of various process parameters of effluent sample, different approaches were used like one factor at a time and statistical optimization through response surface methodology (RSM). Further to validate the above data, enzyme activity, total phenolic concentration, GC–MS analysis and seed germination test were also performed. The ligninolytic enzymes produced were characterized as laccase and Manganese peroxidase (MnP). In lignin degradation and decolourization studies, consortia 1 (K. pneumoniae NITW715076_2 + K. pneumoniae NITW715076_1) (82.31%) was found more effective when compared to axenic culture (K. pneumoniae NITW715076_2) (74.1%). In RSM studies, Laccase and MnP activities were increased by 20% and 18%, respectively, as compared to one factor at a time optimization method. In addition, the enzyme activity for laccase and MnP after prediction by RSM was found 53338 IU/L and 147900 IU/L, respectively. The R2 values for both the enzymes were found to be significant. Further, GC–MS analysis also showed the degradation of different organic pollutants in effluent. Lastly, the seed germination test using consortia 1 corroborated the evidence of detoxification of industrial effluent. Effluent treated by consortia 1 showed better results in degradation and decolourization of lignin and their derivatives. Therefore, consortia 1 can be used for various industrial purposes like fruit juice clarification, diagnostic purposes and enhanced bioethanol production.

Combined biological and advance oxidation processes for paper and pulp effluent treatment

During recent years, the socio political pressure to develop suitable technologies capable of treating wastewater from the paper and pulp industry has increased due to strict environmental regulations. System closure could potentially lead to substantial operating and discharge cost savings. This study evaluates the potential of combining an aerobic moving bed biofilm reactor (MBBR) (biological) and a Fenton-like system (advanced oxidation processes) for treating recycle mill effluent (RME). The performance of the moving bed biofilm reactor (MBBR) was evaluated at three different hydraulic residence times (HRT). The HRT used were 24, 16 and 5 h and the corresponding total chemical oxygen demand (COD) removals were 55, 49 and 43% respectively. The volatile organic acids (VOA) removals were 63.5, 58.7 and 53% respectively. The Kincannon-Stover model was used to describe the kinetic behaviour of the MBBR. The calculated KB and Umax parameters for the COD were 26.37 g.L−1.d−1 and 15.06 g.L−1.d−1 respectively. For the VOA, the KB and Umax parameters were 11.81 g.L−1.d−1 and 8.87 g.L−1.d−1. The Fenton-like experiments were carried out in batch runs. The first experiments were carried out to determine the optimal reaction parameters. Maximum COD removals were found to be at a pH of 3.33, Fe3+ dosage of 1,000 mg/L and H2O2 of 14.55 mM. Pseudo-first order reaction kinetics was used to describe the kinetic characteristics of the Fenton-like treatment system. The calculated kinetic parameters ηmax (%) and kCOD (min−1) were 53.8% and 0.112 min−1 respectively at a pH of 3.24, Fe3+ dosage of 250 mg/L and a H2O2 dosage of 77 mM.

Developing performance-property correlation for fly ash as adsorbent for pulping effluents

Wood based fly ash has a limited use in industry currently, but it can be used as an adsorbent in wastewater treatment systems. In this work, physical (e.g., surface area, pore size) and chemical (e.g., compositions) properties of fly ash were investigated and related to its performance in removing lignocelluloses from a pulping spent liquor (SL). To achieve this goal, two different industrially produced wood-based fly ash (FA) samples, FA1 and FA2, were used. The results revealed that the removals of COD, lignin and turbidity were 80%, 95% and 96% for FA1 and 30%, 25% and 50% for FA2, respectively, under the experimental conditions of 100 g/L dosage at 25 °C for 1 h. The heating value of fly ash was also increased after adsorbing the organic compounds. To investigate the impact of inorganic components, fly ash samples were incinerated at 525 and 900 °C, and then they were used for removing organic materials. The analysis depicted that the removals were limited when incinerated FA1 was used, while incinerated FA2 at 900 °C had more organics removal than FA2. Overall, it was concluded that even though the physical properties of fly ash impacted the adsorption of organics, the chemical compositions of fly ash played a more crucial role on its performance in removing lignocelluloses.

Impact of Coffee Pulp Effluent on Biological and Chemical Properties of the Soil

Impact of Coffee Pulp Effluent on Biological and Chemical Properties of the Soil

Hetero-catalytic hydrothermal oxidation of simulated pulping effluent: Effect of operating parameters and catalyst stability

In the present study, activated carbon (AC) supported bi-metallic catalyst (3.3Cu/2.2Ce/4.4AC) was subjected to catalytic wet oxidation (CWO) of simulated pulping effluent at moderate operating conditions (temperatures = 120–190 °C and oxygen partial pressures = 0.5–1.2 MPa). The oxidation reaction was performed in a high pressure reactor (capacity = 0.7 l) with catalyst concentration of 1–5 g/l for 3 h duration. During CWO at 190 °C temperature and 0.9 MPa oxygen pressure, the chemical oxygen demand (COD), total organic carbon (TOC), lignin and color removals from the wastewater were 79%, 77%, 88% and 89%, respectively, while the wastewater biodegradability was enhanced to 0.52 from an initial value of 0.16. TOC mass balance suggested that nearly 86–97% of the degraded TOC was mineralized whereas copper and cerium leaching from the catalyst were in the range of 1–15% and 0.7–1% with respect to their initial amounts. Metal leaching was reduced with increase in the reaction temperature. Global kinetic rate model was also developed using TOC degradation data and the activation energies of two step (rapid followed by slower TOC removal) CWO reaction were determined as 34.2 kJ/mol and 28.5 kJ/mol, respectively.

Utilization of dissolved iron as catalyst during Fenton-like oxidation of pretreated pulping effluent

Abstract Effluent arising from kraft or soda pulping section of a pulp and paper mill is difficult to treat due to the presence of recalcitrant organics such as lignin. In this study, FeCl3 pretreated pulping effluent was subjected to Fenton-like oxidation. Residual dissolved iron from pretreatment step and H2O2 were utilized as catalyst and oxidant, respectively while the initial wastewater pH was 4.0 (unadjusted). The maximum lignin and total organic carbon (TOC) removals of 85% and 48% could be achieved within 2 h of reaction. The oxidation reaction was mediated by hydroxyl radicals (HO ) which were detected by electron spin resonance (ESR) spectroscopy. Moreover, the addition of tertiary butyl alcohol and chloroform (both radical scavengers) as well hydroxyl amine (a ferrous ion recycler) affected TOC removal significantly. The TOC degradation data could adequately be fit in a lumped kinetic model (LKM) and the activation energy was calculated as 50.85 kJ/mol. The nature of chemical compounds in treated wastewater was also predicted using Fourier transforms infrared (FTIR) spectroscopy.

English

English

Pretreatment and in Situ Fly Ash Systems for Improving the Performance of Sequencing Batch Reactor in Treating Thermomechanical Pulping Effluent

In this work, two methods were applied for improving the performance of activated sludge in treating the effluent of thermomechanical pulping process. In one attempt, the effluent of the pulping process was pretreated with 0.2 wt.% of fly ash (FA) at room temperature and 100 rpm for 1 h, and the FA-pretreated samples were further processed by a sequencing batch reactor (SBR) system. In another work, FA (0.2 wt.%) and activated sludge were mixed with the effluent simultaneously in an in-situ system. The results showed that FA asimilation would benefit the removal of non-biodegradable substances, and thus facilitate the decomposition of contaminants by activated sludge in both systems, especially in the in-situ system. The removal efficiencies of 96.1%, 99.1%, 95.2%, 90.51% and 99.5% were achieved for COD, BOD, TOC, lignin and sugar from the effluent, respectively. In addition, the sludge volume index (SVI) of the FA-pretreated and in-situ systems decreased to 100.7 and 75.5 mL/g and the effluent suspended ...

Physico-chemical treatment of pulping effluent: Characterization of flocs and sludge generated after treatment

ABSTRACTThe present study deals with the treatment of simulated pulping effluent (pH = 11, and total organic carbon (TOC) = 1900 mg/L) by acid precipitation and coagulation-flocculation processes. The maximum TOC removal (= 4845 mg/g Al3+) from the effluent was found with Al2(SO4)3 coagulant. Addition of sufloc (a flocculant) improved the sludge settling significantly. Hydrolyzed mono- and polynuclear species generated from Fe and Al coagulants could have resulted in TOC removal. Thermal analysis of sludge showed release of gases like CO, CO2, HCHO, CH3SH and SO2 during combustion. Afterwards, the dissolved metal species in treated wastewater samples should be removed.

Removal of Recalcitrant Organic Compounds From an Industrial Complex Effluent by Heterogeneous Fenton‐Type Treatment

Because of their chemical complexity, industrial chemi‐mechanical pulping effluents are evaporated and burned, in spite of the high associated cost involved in these processes. The aim of this study was to remove recalcitrant compounds from this kind of wastewater using a Fenton‐type treatment. The main parameters involved in the process and their influence on the results were determined. Homemade catalysts based on CuO, Fe2O3, NiO, and ZnO, supported on γ‐Al2O3 have been tested for catalytic oxidation, and the CuO/γ‐Al2O3 catalysts showed the greatest effect on total organic carbon (TOC) reduction (52.7%). A series of two‐level factorial experiments was subsequently applied to evaluate the most favorable range of conditions for CuO/γ‐Al2O3 application. The studied variables were hydrogen peroxide concentration ([H2O2], g/L), active phase content (metal oxide supported on alumina,%), mass of catalyst (metal oxide/alumina system, g), and reaction temperature (°C). The highest reduction of all parameters was obtained at the superior level of all variables with CuO/γ‐Al2O3, achieving reductions of chemical oxygen demand (COD) and TOC between 40 and 50%. Increasing catalyst mass did not produce additional benefit. This variable has a significant effect only on the reduction of aromatic compounds. At its low level, reduction in aromatic content exceeded 80%. Color reduction was influenced only by temperature (maximum reduction of 90%).

Microbial Growth Kinetics and Effluent Characteristics of Paper And Pulp Wastewater under Aerobic Digestion using SBR

The present study is investigated with the treatment of paper and pulp effluent under aerobic using Sequential batch reactor. Various effluent characteristics like, COD, BOD, Color removal efficiency, Turbidity, SVI, AOX and lignin removal were studied with time for different wastewater concentrations. Various effluent characteristics like, COD, BOD, Color, Turbidity, SVI, AOX and lignin removal were studied with time (days). COD of the influent and effluent and MLSS of reactor were determined at different aeration time to generate data for kinetic coefficients. Results proclaim that COD is reduced from 1205 mg/L to 222 mg/L, 2014 mg/L to 452 mg/L and 3368 mg/L to 890 mg/L for low, medium and high concentration respectively. Further, optimization study is carried out for wastewater concentrations using fuzzy logic control. The optimized operating parameters for achieving the maximum removal of effluent found to be microbe dosage of 55 ml and aeration time of 5 hours.

Application of Potent Actinomycete Strains for Bio-Degradation of Domestic Agro-Waste by Composting and Treatment of Pulp-Paper Mill Effluent

Actinomycetes are known to produce an extensive range of bioactive compounds as well as variety of enzymes having multiple biotechnological applications. They are an important source of lignocellulose hydrolyzing enzymes and constitute considerable proportion of the soil or aquatic micro-flora responsible for degradation of biomass in natural environment. Presently, most of the commercially exploited lignocellulases and commercial biodegradation processes rely mostly on fungal or bacterial micro-organisms. Actinomycetes are relatively less explored for biodegradation processes that utilize lignocellulases for solid agro-waste management and waste water treatment. There is also a need to search and explore novel actinomycete strains for various biodegradation applications. This study involved examining the possibility of using only potent actinomycetes strains for the composting process by creating the consortium of such strains that could produce thermo-tolerant and alkali-tolerant key enzymes necessary for the degradation of cellulose, hemi-cellulose and lignin. The newly developed actinomycete consortium was tested for the composting activity and the composting process was optimized. The analysis of the composted material generated under ideal condition, demonstrated desirable physical and chemical characteristics. Paper pulp effluent poses a hazard to waterways due to toxicity. The toxicity of this mill effluent can be attributed to a compound called lignin and its chlorinated derivatives that are let out during the treatment of lignocellulosic constituents. Current study also involves the use of a strain of actinomycete having ability to produce enzyme laccase, which is active under alkaline condition for the treatment of paper pulp effluent. Enzyme laccase is known for its ability to attack phenolic components of lignin and common hazardous component of effluent, polycyclic aromatic hydrocarbons (PAH). Aerobic treatment of effluent by actinomycete strain indicated 21% reduction in COD at pH 7.5 after 14 days under optimum condition. This strain was identified as Streptomyces rochei based on molecular fingerprinting and was reported to be the producer of laccase probably for the first time. LCMS analysis of the treated effluent sample showed the presence of degradation compounds forming after 7 and 14 days of treatment. These compounds showed the degradation of lignin components and other phenolic, non-phenolic components of the effluent by intra molecular re-arrangement, oxidation and ring opening reactions. Overall, potent thermo-tolerant and alkali-tolerant actinomycete strains were successfully isolated and applied for bio-degradation of domestic agro-waste by composting and treatment of pulp-paper mill effluent. The consortium of these strains may be further utilized for scale-up studies in order to assess its commercial feasibility for biodegradation processes.