Paper Mill Industry Research Articles

Influence of Residual Black Liquor in Pulp on Wastewater Pollution after Bleaching Process

The influence of residual black liquor in pulp on wastewater pollution after the bleaching process was studied. The results show that the CODCr in bleaching effluent has a remarkable linearity with bleaching loss of pulps without residual black liquor. For pulps with some residual black liquor, more than 34% of the overall CODCr is produced by the residual black liquor. It follows that more effective washing to reduce the residual black liquor is an appropriate way to control the pollutant discharges from pulp and paper mill industry.

Separation of pollutants from pulp mill wastewater by electrocoagulation

The paper and pulp mill industry is facing major problems in the disposal of wastewater generated from bleaching and pulping processes. Hence, effective treatment of pulp and paper mill wastewater is still a challenging task. In view of these factors, a research study was undertaken to investigate the feasibility of electrocoagulation process for the treatment of paper mill wastewater. The studies were conducted in an EC reactor of 1.50 L capacity with aluminium electrodes. The effects of operating parameters such as pH, current density, electrolysis duration and applied voltage on turbidity, TOC and COD removal efficiency have been investigated. The maximum COD, turbidity and total organic carbon (TOC) removal efficiencies of 89%, 96% and 72% respectively were obtained at pH 7 when the applied voltage was 12 V at electrolysis duration of 40 minutes. The specific energy consumption for the electrochemical treatment of a paper and pulpmill wastewater was estimated.

Separation of pollutants from pulp mill wastewater by electrocoagulation

The paper and pulp mill industry is facing major problems in the disposal of wastewater generated from bleaching and pulping processes. Hence, effective treatment of pulp and paper mill wastewater is still a challenging task. In view of these factors, a research study was undertaken to investigate the feasibility of electrocoagulation process for the treatment of paper mill wastewater. The studies were conducted in an EC reactor of 1.50 L capacity with aluminium electrodes. The effects of operating parameters such as pH, current density, electrolysis duration and applied voltage on turbidity, TOC and COD removal efficiency have been investigated. The maximum COD, turbidity and total organic carbon (TOC) removal efficiencies of 89%, 96% and 72% respectively were obtained at pH 7 when the applied voltage was 12 V at electrolysis duration of 40 minutes. The specific energy consumption for the electrochemical treatment of a paper and pulpmill wastewater was estimated.

Determination of nanofiltration membranes for reuse of paper mill industry wastewater

Determination of nanofiltration membranes for reuse of paper mill industry wastewater

Potential use of sludge cake from paper mill wastewater treatment as degradable flower pot.

Sludge cake produced in paper mill industries is disposed into a landfill and may cause the environmental and health problems. Now many researchers have tried to recycle rigid materials from it for the purpose of decreasing its volume. The aims of this study were to clarify three hypotheses: (1) whether a flower pot would be economically made from sludge cake, (2) whether it would be safe for environment, and (3) when vegetables would grow enough in it, whether they would be safe for human consumption. Sludge cake was mixed with soil (soil texture: heavy clay). The circular plaster mold was used as a fixed mold. As the toxicological testing, leaching test and seed germination test were used. Heavy metal concentrations in vegetables grown in the flower pot were measured. The flower pot was sufficiently formed by drying in natural open air. The results of leaching test showed three heavy metals, lead, nickel and copper, were lower than the standard in Thailand. The seed germination test suggested no negative effects of the flower pot on the germination of Chinese kale. Lead concentrations in the Chinese kale were higher than the recommended maximum level in leafy vegetables. The new flower pot can be made from sludge cake with soil. It has the possibility to have no negative effect on the environment. Although the vegetables grown in this flower pot are not suitable to eat, this flower pot has the possibility to solve the environmental and health problems.

Dynamic Modeling of an Activated Sludge Process: Case Study on Paper Mill Effluents

AbstractThe aim of this paper is to propose a step by step method to establish and validate a relevant, dynamical model of the activated sludge process for the paper mill industry. The model is established by considering the specificities of the effluent to be treated. It uses the biochemical oxygen demand (BOD) measurement, which allows a direct correlation between the state variables of the model and the measurements. This model is validated on a pilot plant of semi-industrial size fed with industrial paper mill effluents. The parameter estimation is based on an analysis of the sensitivities. The results are compared with a model based on chemical oxygen demand (COD) partitioning which is issued from the simplification of the activated sludge model number 1 (ASM1) model. Finally, the model dealing with BOD measurements not only shows the best performances, but is also the easiest to implement, overcoming one main obstacle to efficient monitoring and control in paper mill wastewater treatment plants.

ASSESSMENT OF HEAVY METALS LEACHING FROM (BIO)CHAR OBTAINED FROM INDUSTRIAL SEWAGE SLUDGE / IŠ GAMYBINIO NUOTEKŲ DUMBLO PAGAMINTOS BIOANGLIES SUNKIŲJŲ METALŲ IŠPLOVIMO ĮVERTINIMAS

Biochar can be produced from many various feedstock including biomass residues such as straw, branches, sawdust and other agricultural and forestry waste. One of the alternatives is to obtain biochar from industrial sewage sludge, however, the use of such a product could be limited due to high quantities of heavy metals in the biochar as a product. Total concentration of heavy metals provides only limited information on the behavior of heavy metals, therefore, batch leaching and up-flow percolation leaching tests were applied to study the leaching of heavy metals (Cd, Pb, Cr, Ni, Zn, Cu) from (bio)char produced from two types of sewage sludge: from paper mill and leather industries. Bioanglis gali būti gaminama iš daugelio įvairių pramonės žaliavų, įskaitant biomasės liekanas, pavyzdžiui, šiaudus, šakas, pjuvenas ir kitas žemės ūkio ir miškininkystės atliekas. Viena iš alternatyvų – bioanglį gaminti iš pramonės nuotekų dumblo, tačiau tokį produktą galima naudoti ribotai dėl jame esančio didelio sunkiųjų metalų kiekio. Iš bendrosios sunkiųjų metalų koncentracijos tyrimų galima tik ribotai spręsti apie sunkiųjų metalų pasiskirstymą, todėl buvo taikomi du tyrimai: tyrimas, perkoliuojant atliekas vienakrypte srove, bei dvipakopis partijos (tyrinio) tyrimas siekiant išanalizuoti sunkiųjų metalų (Cd, Pb, Cr, Ni, Zn, Cu) išplovimą iš bioanglies, pagamintos iš dviejų rūšių nuotekų dumblo: popieriaus gamybos ir odos pramonės.

Assessment of Fish Health Status Under Long-Term Water Pollution : Vygozero Reservoir , North-West Russia

Environmental pollution and its effects on the health of aquatic ecosystems is a great problem that has been studied intensely in the last years. The Vygozero reservoir is one of the largest water bodies of the Karelian Republic. Its ecosystem has undergone significant changes since the 1930s mainly due to anthropogenic influence from the development of pulp and paper mill industry leading to accumulation of toxic contaminants and eutrophication. At present, the water body has been shown to be also polluted by hydrocarbon products and heavy metals. Among the huge changes in Vygozero ecosystem is the decrease of some fish populations and partial loose of commercial fishing importance. Despite the obvious changes in fish population the chronic biological effects of the Vygozero reservoir pollution on fish organism are poorly studied. This study is concerned with the evaluation of pollution influence on fish health status and establishment relation between fish health and environmental quality. The parameters selected for this aim were the occurrence of gills, liver and kidney alterations, as histopathological changes are widely used as biomarkers in the evaluation of the health of fish exposed to contaminants. Our findings confirm chronic pollution of the Vygozero reservoir. Histological analysis of fish tissues revealed a variety of progressive, regressive, inflammatory, circulatory disturbances and neoplastic changes. Observed histological alterations indicate that organism of fish from Vygozero reservoir responses to the impaired environment quality. Revealed histopathologies are sings of metabolic disorders, immunity suppression, compensatory reactions development and functional abnormalities in vital organs of studied fish. The results of the study correspond to the prior research devoted to ascertain tissue changes in different fish species taken from an area with chronic multiple anthropogenic impact. So it can be concluded that histopathological lesions are result of long-term effect of toxic xenobiotics.

Fast Pyrolysis of Residues from Paper Mill Industry to Bio-oil and Value Chemicals: Optimization Studies

Biomass is a renewable energy and had been recognized as a promising feedstock for producing bio-fuels. In this work, pyrolysis of black wattle residues was investigated with the aim to study the product distribution and their chemical composition and predicting the optimal condition for maximized bio-oil especially aromatics content by using a two level factorial design of experiment. The pyrolysis were performed at temperature of 380 – 580 oC, Under screw feeder carried the biomass residues and weight of dolomite as catalyst of 1-5 wt% inside pyrolyzer with nitrogen gases flow rate of 20 to 80 cm3/min The detention time was controlled by reactor screw feeder at feeding rate of 120 to 240rpm. Based on the analysis from a design-expert program to determine the appropriated condition of experiment was 515.18 oC, 120.01rpm of feed rate and 20.00 cm3/min of nitrogen flow rate using 5.00wt% of dolomite catalyst. The elemental and physicochemistry analysis of bio-oil were determined, the chemical composition also investigated using gas chromatography-mass spectrometry and 1H NMR. The composition of bio-oil mainly oxygenated compound with high molecular weight and phenol. The results show that the biomass residual can be considered as a potential alternative fuels and relevant to valuable chemical feedstock.

Recovering organic matters and ions from wastewater by genetically engineered Bacillus subtilis biomass

Water pollution causes substantial damage to the environment and to human health, and the current methods to treat pollution suffer from high cost and low efficiency, resulting in increased environmental damages. Using genetic modification and functional selection, we developed a novel biosorbent from Genetically Engineered Bacillus subtilis (GEBS) cells. At a ratio of biosorbent to direct blue dye of about 1:1.25 in a water solution, the dye pigments can be completely adsorbed in 40 s, decreasing COD to zero. Contrary to other biosorbents, ions such as Fe2+ and Cu2+ have significant advantages in terms of the adsorbing efficiency. The GEBS biomass can therefore capture both organics and ions from wastewater simultaneously and achieve co-precipitation in 2–10 min, which are features critical for practical applications of wastewater treatment. In addition, we used six different eluting solutions to regenerate used biomass, all resulting in renewed, highly efficient color and COD elimination capacities, with the best elution solution being NaHCO3 and Na2CO3. For practical applications, we showed a high COD elimination rate when using the GEBS biomass to treat raw water from textile enterprises, paper mill, and petrochemical industries. Compared with currently available adsorbing agents, the GEBS cells can adsorb organic and ion waste much faster and with much higher efficiency, can be regenerated and recycled efficiently, and may have broad applications in treating organic water pollution.

Effect of Methylisothiazolinone on Biological Treatment: Efficiency of SBRs and Bioindicative Studies

Methylisothiazolinone (MIT) is widely used as biocide in hair and skin care products and in high concentrations, more than 150 mg/L, in cooling towers in the paper mill and refinery industry. This product has been recognized as a potent contact allergen and is discharged to the wastewater treatment plants (WWTP) from industrial processes or domestic usages. However, the role of MIT in biological treatment has not been characterized, and therefore, the effect of MIT on the composition and performance of activated sludge has been analyzed. For this purpose, a sequential batch reactor was fed with a synthetic solution containing 5 mg/L of MIT. Addition of MIT had shown no significant effect on organic matter metabolization (dissolved organic carbon [DOC] removal remained constant at 80–90%). On the contrary, a loss of efficiency in the nitrification process occurred (ammonium removal decreased from 90% to 20% per cycle throughout the experiment), first affecting the nitrite oxidizing bacteria and, after around 40 cycles, also the ammonium-oxidizing bacteria disappeared, as shown by fluorescence in situ hybridization analysis. Bioindicative studies based on counts of protozoa and sludge biotic index indicated that, at the end of the process, a stable and well-colonized protozoa community was obtained. Finally, respirometric tests indicated some acclimatization of the heterotrophic bacteria to MIT, as shown by shorter lag periods when the sludge was previously fed with MIT. The role of MIT in biological treatment has been characterized to increase the knowledge about this pollutant effects on activated sludge to improve WWTP performance.

Metal Mobilization in Tailings Covered with Alkaline Residue Products: Results from a Leaching Test Using Fly Ash, Green Liquor Dregs, and Lime Mud

The in situ dynamics of repeated percolation of rainwater through unoxidized mine tailings was simulated using a modified column test to predict long-term weathering characteristics. Fly ash, green liquor dregs, and lime mud waste materials from the paper mill industry were used in the column tests to assess the effect of alkaline paper mill residue on pH buffering and controlling the mobility of metals and semi-metals from the tailings. The experiment was continued for 15 cycles, each comprising reaction, leaching, and idle steps (1 week per step). The cumulative percolated water through the tailings represented a liquid:solid ratio of 1.6. The leached content of inorganic elements decreased with time in both the covered and the uncovered tailings. The presence of the alkaline materials consistently reduced the mobility of most contaminants (e.g. Cd, Co, Cr, Mn, Ni and Zn), but not As. The leachate was modeled using PHREEQC. XRD analysis of the remaining tailings samples after termination of the test showed detectable variations in mineral composition. The alkaline residue products all fulfilled the requirements as a cover material from a geochemical prospective, with the exception of As. The green liquor dregs and lime cover increased the pH of the tailings more rapidly than did the fly ash.

Construction technique of disposable bin from sludge cake and its environmental risk.

Now, a lot of researchers have tried to make recycled rigid materials from the sludge cake produced in paper mill industries for the purpose of decreasing its volume. In this study, the researchers tried to make economically a disposable bin and to examine whether it is toxic or not to the outside environment. To make a disposable bin, the researchers used the sludge cake, a plastic basket, as a fixed mold, white cloth or newspaper, as a removable supporter for wrapping around the mold, and latex or plaster, as a binder. The strength of the samples was measured by tensile-stress testing. The water absorption was evaluated by Cobb test. As toxicological tests, leaching test and seed germination test were selected. It was possible to form the disposal bin from the cleaned sludge cake. They seemed safe to carry garbage in the industry judging from the results of tensile-stress testing. Some of them showed less water absorptiveness (higher water resistance) in the results of Cobb test. The results of leaching test showed small values of three heavy metals, lead, nickel and copper, in the leachate. The seed germination test suggested no adverse effects of the bins in the clay and sand on the tomato growth. The results of these tests suggest that the bins have good strength, sufficient water resistance and no toxicological effect on the environment. This new recycled bin has the possibility to solve the environmental and health problems at disposing the sludge cake.

Nghiên cứu chế tạo vật liệu compozit trên cơ sở PbO2 ứng dụng làm điện cực anôt để xử lý nước thải nhà máy sản xuất giấy bằng phương pháp điện hóa

PbO2 was electrosynthesized on 304 stainless steel substrates by current impose method in 0.1M Pb (NO3)2 + 0.1M HNO3 solution with and without TiO2 micro-particles. The results of durability testing of the material in 1M H2SO4 acid solution at 200 mA/cm2 current density for duration of 5400 seconds showed that 0.1M Pb(NO3)2 + 0.1M HNO3 solution with 3 g/L TiO2 is suitable for synthesis of PbO2-TiO2 composite electrode. The analysis by scanning electron microscopy combined with energy dispersive X-ray showed the presence of TiO2 in the PbO2 plating. The decomposition yield of polluted organic compounds in wastewater of Lua Viet paper stock company on PbO2-TiO2/TKG304 (92.9%) anode was found higher than that of PbO2/TKG304 electrode (82.1%) and the polluted organic compound treatment in wastewater of paper mill industry by Fenton electrochemical method is better than electrochemical method.

Effect of process parameters in surface roughness during turning of GFRP pipes using PCD insert tool

Glass fiber reinforced polymer (GFRP) composite pipes are finding its increased applications in variety of engineering applications such as water softening plants, desalination plants, paper mill industry, marine water treatments. However, the users of FRP are facing difficulties to machine it, because of fiber de-lamination, fiber pull out, short tool life, matrix de-bonding and formation of powder like chips. The present investigation focuses on the effect of process parameters for surface roughness of glass fiber reinforced polymer (GFRP) composite pipes. Experiments were conducted based on the high speed turning centre (CNC) using poly-crystalline diamond (PCD) tool. The process parameters considered were cutting speed, feed, depth of cut, and work piece type (E-Glass mat and E-Glass woven specimen). Both pipes are fabricated using the filament winding process. The pipe consists of 70 percent epoxy polyester resin and 30 percent glass fiber. A comparative study has been undergone between the E-Glass woven and E-Glass mat fiber reinforced composite material. The mechanical properties were also conducted as per ASTM standards. Based on the results, it was observed that good machinability was obtained at lower cutting speed, feed rate, depth of cut for mat fiber reinforced GFRP pipe and at high cutting speed, lower feed rate, depth of cut for mat fiber reinforced GFRP pipe.

Effectiveness of Electrooxidation Process for Stabilizing and Conditioning of Urban and Industrial Wastewater Sludge

The objective of this research was to investigate the performance of an electrochemical process for enhancing dewaterability and stabilize wastewater sludge from paper mill industry (PMS) and municipal wastewater (MWS) treatment plants. The treatment was conducted using 13.2 kg of sulfuric acid (H2SO4) per ton of dry sludge (TDS) and 200 kg of NaCl/tds as electrolytes, at a current intensity of 8A for 60 min. The process was efficient for increasing the dryness of PMS with an average value of 25.3 +/- 1.2% (w/w). By comparison, the electrochemical treatment using MWS allowed increasing the dryness to 33.4 +/- 1.4% (w/w). Simultaneously, the process was found to be effective in removing pathogen indicators (abatement > 4 to 5 log units of total and fecal coliforms) using either PMS or MWS. At the same time, it preserved the fertilizing properties of sludge by maintaining the concentration of P(tot), N-TKN and COD in dewatered sludge. The substitution of sodium chloride (used as electrolyte) by sodium sulfate (Na2SO4) combined with hydrogen peroxide (H2O2) allowed reducing the formation of organo-chlorinated compounds: more than 50% of chloroform was reduced, 86% of toluene was reduced and 59% of phenolic compounds was reduced.

Treatment of wastewater from pulp and paper mill industry by electrochemical methods in membrane reactor

The treatment of wastewater from a pulp and paper mill plant using electrochemical methods was performed at a laboratory bench-scale at ambient temperature (∼30 °C). The effects of wastewater dilution (10- to 100-fold), circulating water flow rate (0–3.95 l/min), current density (1.90–3.80 mA/cm2) and sodium chloride concentration (0–3.75 g/l) were ascertained. The results demonstrated that this methods can facilitate the disappearance of the oxidative coupling unit of lignin as well as other organic and inorganic compounds, measured in terms of the removal of color, total biological- and total chemical oxygen demand (BOD and COD), and the total suspended and dissolved solids (TSS and TSD). In addition, the electrochemical method was more effective at reducing the pollutant levels, produced a smaller quantity of low-density sludge and had a low operating cost per unit quantity of COD. After optimization, the electrochemical method operating in a batch mode enhanced the removal of color, BOD and COD at around 98%, 98% and 97%, respectively, whilst in a continuous mode at the steady state condition (8 h after the start-up time) the color, BOD and COD levels were reduced by around 91%, 83% and 86%, respectively.

Industrial wastewater re-use: closure of water cycle in the main water consuming industries – the example of paper mills

Paper mill, chemistry, textile and food processing industries are high water consumers. Within the framework of the European project Aquafit4Use, the possibility to close the on-site water loop is studied. The aim is to find new technologies or innovative treatment trains to produce water that is ‘fit for use’ in the industrial process; an example of a paper mill is given. Laboratory-scale tests on nine technologies were carried out to determine the best suitable treatment train: anaerobic process (already on site) → aerobic process (already on site) → Flexible Fibre Filter Module → softening → nanofiltration → evapoconcentration or ozonation on nanofiltration (NF) concentrate. This treatment train is currently compared on site at pilot scale to another treatment train including some modifications on the existing on-site biological treatment: anaerobic process → softening → membrane bioreactor → nanofiltration → evapoconcentration or ozonation of NF concentrate.

Study on Physico-Chemical Parameters of Waste Water Effluents from Taloja Industrial Area of Mumbai, India

The present research work deals with the study of some of the important physico-chemical parameters of industrial waste water effluents collected from Taloja industrial belt of Mumbai. The study reveals that engineering, paper mill, fine chemical, dyes, paint, pharmaceutical, petrochemical and textile industries are some of the major industries re- sponsible for polluting the surrounding aquatic environment. It was observed that pH values of effluent samples collected from paint, pharmaceutical and dyes industries were slightly above and below the limit of 6.5 to 8.5 by ISI and WHO. The effluent samples collected from textile industries shows extremely high Total Dissolved Soild (TDS) content of 12023.6 mg/L and correspondingly high Total Solid (TS) content of 13499.2 mg/L. The chloride content in the effluents from textile industries was 238.4 mg/L which was significantly high than acceptable limit of 200 mg/L set by WHO. The BOD values of effluent samples collected from pharmaceutical, dyes, engineering and paint industries were 1047.3, 776.2, 604.8 and 535.8 mg/L respectively which lie above the maximum permitted BOD content of < 100 to 300 mg/L. The COD values in the different industrial effluent samples were also very much higher than maximum permissible limit of 4.0 mg/L according to USPH Standard. The overall results highlight towards the discharge of highly polluted waste water effluent from indus- tries of Taloja Industrial area of Mumbai. These industrial effluents have resulted in pollution of nearby Kasardi River thereby affecting the growth of vegetation and aquatic life. The results of the present investigation point out the need to implement common objectives, compatible policies and programmes for improvement in the industrial waste water treat- ment methods.

Reuse of Paper Mill Ash in Plaster Blends

This work is part of a broad research conducted to study the re-use of industrial wastes in an economical and environmentally sustainable manner. Re-use of lightweight ash from the paper mill industry in the manufacture of plaster blends is examined in this study. Lightweight ash is produced during the combustion process of de-inking sludge. Studies demonstrate that lightweight ash is an excellent ingredient in the production of cement mortars and/or pozzolanic mortars to be used as plaster. In this research, ash valorization was researched by investigating the efficacy of the ash as it is, as a substitute for very fine sand. If properly mixed at an optimal mix proportion, the mechanical strength ranges from 4÷10MPa with specific gravity between 1150 and 1350 Kg/m 3 . Water absorption may be reduced to a very low level with silane-based surface treatment.