Introduction The complexity and diversity in production of Paper and high volume of water consumption in each steps, has made the Paper industry as one of the largest industrial consumer of water after the chemical and metal industry (Covinich, et al, 2014). High water consumption is between 76 to 227 cubic meters per ton of product (Ginini et al, 2014). The wastewater, in addition to high flow, contains high concentrations of BOD, COD, pH, suspended solids, color and turbidity. Pollution of water bodies created by these industries is one of the major world concerns (Khansothong, 2009). More than 250 chemical substances have been identified in various stages of Paper production. Apart from a large variety of air pollutants and their complex building, many compounds in wastewater are poorly water soluble, and their resistant to harsh treatment processes, particularly biological filtration and reddish-brown color of has created many problems for treatment processes (Birjandi, et al, 2014). The other part of these pollutants, consist of chemical compounds such as chlorinated compounds, phenols, absorbable organic compounds (AOX), and also additives that are used during the Paper-making industry processes such as chemical pulping process. All of this factors have caused that wastewater of Paper industry has one of the most difficult water treatment, which associated with the complexity of processes (Zahrim et al, 2007). The majority of industrial wastewater arises from pulp and Paper pulping process Depending on the type of pulping process, wood and Paper industry produce various pollutants. Raw materials for pulp of Old Corrugated Container (OCC) unit supplied from waste Paper and cardboard waste. Raw material to produce Kraft pulp is hardwoods and softwoods (karmali 2014). Research studies show that a variety of methods have been used for wastewater treatment in factory of pulp and Paper. It can be noted that in the following ways: physicochemical treatment, settling and filtration, coagulation and sedimentation, adsorption, chemical oxidation, membrane filtration, ozonation, biological treatment, activated sludge, aerated lagoons, aerobic biological reactor, anaerobic treatment method, fungal treatment, combined treatment process (Buyukkamaci and Koken 2010). Biological treatment methods are generally preferred due to environmental impacts and low cost and it is a Conventional method for treating wastewater containing organic materials. One method of biological treatment is Activated Sludge. This method produces variable sludge settling characteristics and Often is sensitive to shock loading and toxicity. Their capacity to remove toxic biodegradable substances is extremely low (Katal 2011). The barriers to biological systems require large surface area, difficult to control the population of microorganisms, control of pH, temperature and nutrients for creating bulking sludge (Tambosi et al 2006). Wastewater of Pulp & Paper has restricted the use of biological methods, due to the presence of toxic compounds with Low capable of biodegradation. For this reason, the uses of chemical methods have become more acceptable (Bianco 2011). Among chemical processes, advanced oxidation processes are used for organic load reduction or toxicity of waste water (Martinez et al 2003). So this method has become a competitive technology to remove organic contaminants that are refined by conventional methods. Chemical oxidation is based on the production of hydroxyl radicals oxidizing agent in order to mineralization as a complex chemical composition of wastewater. Hydroxyl radicals are a strong oxidizing with power of oxidizing 2. 23 V in comparison to conventional oxidizers (Perez et al 2002). Fenton process (H2O2/ Fe+ 2) One of the most common advanced oxidation process that is used for wastewater treatment and it is possible to use it in different scales used because of the ease of implementation, low reaction time, process of coagulation and flocculation, non-toxic compounds and low economic cost in comparison with the other methods (Neyens 2003) (Barreto-Rodrigues et al 2009) (Badawy et al 2009). Materials and methods Studied Wastewater was prepared from pulp and Paper mill in Iran. In the investigated factory, Depending on the used process, a Kraft pulp or OCC pulp generally produced two main wastewaters. One of them is Wastewater fiber and other is alkaline Wastewater. Considering the type and volume of produced waste water, a mixture of the two wastewaters (in the ratio 3: 1) was moved to laboratory to evaluate the treatability. In this study for optimizing variables, five factors pH, temperature, reaction time, concentration of iron and hydrogen peroxide concentration are considered, the response surface methods (RSM) was used in the application minitab17 for Optimizing of these factors. Response surface methodology is based on central composite design is one of the statistical methods for design of experiments, modelling, evaluating the effects of several factors, optimal conditions for favorable response and reduce the number of tests. 33 designed tests on the Fenton process with a batch Pilot scale was done in a Pyrex cylinder with capacity of 500 ml. After transferring the mixture of fiber and alkaline Wastewater, the Pyrex was placed on a magnetic stirrer equipped with a thermostat to adjust the temperature. Since the Fenton reaction occurs in an acid environment, Wastewater after acidification with sulphuric acid (H2SO4) to set a normal pH was subjected to specified concentrations of iron salt As a catalyst (FeSO4· 7H2O, Merck) and finally, the concentration of hydrogen peroxide (H2O2) 30% w/w were added to it slowly and at a constant temperature until the hydroxyl radical OH° will be produced. When hydrogen peroxide was added to solution, it was considered as the start time of reaction and at the end of reaction time to neutralize, added to hydroxide sodium sewage compound to get PH=8 (NaOH, merck) and after the addition of 0. 5 ml of polyelectrolyte as a coagulant enter into the tank of solid liquid separation. COD measurement, using reactor and close reflex method was performed according to methods described in standard methods. Results and discussion: The results showed to remove organic material and achieve maximum COD removal, optimum values of pH, reaction time, reaction temperature, concentration of Fe (II) and H2O2 concentrations, are respectively 3. 5, 17. 5min, 32. 5° C, 6Mm and 27. 5Mm. In these condition, if chemical oxygen demand percent of waste wood and water in the following diagram showed that more than 90% of COD will be removed. The results of analysis of variance (ANOVA), to test the utility of model are according to table 1. Table1: results of Analysis of Variance response surface model in COD removal p-value F-value Mean square Sum of squares Degrees of freedom source 0. 001(significant) 50. 46 38. 8 3445. 3 28 model-7. 59 53. 11 5 residual 0. 878(insignificant) 1. 4 0. 91 23. 6 2 Lack-of-fit--6. 68 29. 51 3 Pure error--46. 39 3498. 11 33 total Press=515 R2adj=0. 965 R2predic=0. 83 R2=0. 985 The high amount of R2 and its proximity to number one implies that the COD removal can be well defined by the model and version of the utility is sufficient. Significantly of model for COD removal is expressed by the amount of F, which is equal to 50. 46. also, no significantly of the test, confirming the lack of fitting data with selected model is good fit. This means that there isn't significant portion between lack of fit and amount of pure error. Survey results show that, RSM is an effective way to optimize variables of Fenton process. And there is good agreement, between the predicted values by the model and the results of test. Wastewater of wood and Paper, to a large extent is purified by the Fenton reaction. This treatment will depend on many variables. pH should be adjusted to ensure the stability of the catalyst. Iron remains stable in an acid environment and reduction potential of response system will be reduced. In pH lower than 3. 5, there is (Fe (II) (H2o)) +2 which is less reactive with hydrogen peroxide. Producing a smaller amount of hydroxyl radicals reduces efficiency of the organic matter decomposition. What is important at very low pH, aggregation effect of hydroxyl radicals is by.

Background and objectives: Paper bleaching is a concern of many conservationists. Research has been conducted with the aim of evaluating some traditional bleaching materials used in the preservation of documents and books, such as hydrogen peroxide and sodium borohydride, which shows that these materials do not significantly improve the mechanical properties of historical Papers. Also, investigating the effect of reducing agents on oxidized Papers has shown the effectiveness of tert-butylamine borane complex. In another study, five dyeing processes with oxidizers (calcium hypochlorite, hydrogen peroxide in two concentrations, light bleaching and potassium permanganate) and two dyeing processes with reducing agents (sodium borohydride and tert-butylamine borane) were compared. And their effect on pure cellulose (Whatman filter Paper) and two different historical Papers have been investigated. The results indicate that all the tested dye removal methods have led to a clear increase. Due to the differences of opinion, in this research, the effectiveness of two reducing agents sodium borohydride and sodium dithionite on the appearance and structural characteristics of Paper is investigated.Methodology: In this research, Whatman Filter Paper No. 1 (Whatman Filter Paper No. 1) made in England with a thickness of 180 microns, a diameter of 11 cm, a base weight of 87 grams per square meter and an ash percentage of 0.06% was used. Chemical reagents including potassium persulfate, sodium borohydride and sodium dithionite in the highest purity were prepared in a laboratory from Merck, Germany.Three solutions including potassium persulfate (2% by weight/volume), sodium borohydride (1% by weight/volume), sodium dithionite (1% by weight/volume) in distilled water (distilled water, pH; 7), to perform tests on zinc. Paper samples have been used by immersion.Whatman filter Paper samples were subjected to oxidation in 2% peta persulfate in distilled water for 2 days (48 hours) and then the samples were immersed. Next, the identified samples were modified by two solutions of sodium borohydride and sodium dithionite 1% in distilled water for 1 to 5 hours and then purified in holy water. Also, the samples were subjected to accelerated aging according to ASTM standard number D4714-96 at a temperature of 90±2 centigrade and a relative humidity of 50±2% for 384 hours. Test methods include potentiostat, colorimetry, tensile strength, pH measurement, scanning electron microscope and infrared examination.Results: The results show that potassium persulfate is the most neutralizing solution among the three solutions used on the first day, and it also indicates the reducing power of two solutions of sodium dithionite and sodium borohydride, which according to the test results, sodium borohydride is the reducing power. Compared to sodium dithionite. The sample prepared with pH 92.3, after accelerated aging, was accompanied by an increase of several units of pH after modification with two reducing substances. Examining the data obtained from the tensile strength test shows that in comparison with the tested samples with a tensile index of 1.06, the samples modified with sodium borohydride and sodium dithionite increased the index in all five modified periods. Tensile of Paper samples. The infrared spectrometry investigation of the samples modified with sodium borohydride and sodium dithione shows that this old material improves the structure of cellulose after aging by reviving the C=O bonds to C-O and reducing the area of 1640 cm-1. Accelerated. The reduction of the absorption band in the region of 1640 cm-1 has been opened in almost all time cases with this material compared to the modified sample. Based on the data, samples modified with sodium borohydride and sodium dithionite had a significant increase (approximately 25 units) in the L-factor (light-darkness) after aging, indicating that two substances have increased the brightness of the sample by reviving the color compounds. In the microscopic examination of the surface of the fibers, in the samples identified with potassium persulfate, local separation of the fibers is observed. In the samples modified with sodium borohydride and sodium dithionite, fibers with higher consistency and entanglement are observed.Conclusion: Double bonds and carbon groups in Paper samples formed with potassium persulfate have been the main responsible for the yellowness and darkness of the Paper, the reducing agents sodium borohydride and sodium dithionite reduce this aldehyde and ketone to hydrocarbon and as a result. With the loss of multiple conjugates, the light absorption of the Paper is reduced and this causes the Paper to lighten. The double bonds and their regeneration also cause rearrangement of the chain cells, which has resulted in increasing the mechanical resistance and strength of the Paper samples.

Monitoring and evaluation of transformers are essential to prevent their insulation failure. In this Paper, the use of 2-furan-carboxaldehyde (2-FAL) and methanol (MeOH) concentrations as the main products of Paper insulation degradation, and insulation condition markers, has been studied. In order to study the degradation process and production of degradation products, the thermal aging process of the transformer insulation system was implemented in laboratory conditions. The results of laboratory studies show that in the early stages of degradation the amount of MeOH is significant compared to 2-FAL. Also, the estimation of the degree of polymerization (DP) in the early stages of degradation (DP>800) through MeOH concentration and with decreasing DP (DP <800) through 2-FAL concentration is closer to the real value. The results of studies performed on 35 distribution transformers confirm the production of significant amounts of MeOH in the early stages of degradation. Also, the estimated DP values for the studied transformers were obtained through 2-FAL and MeOH concentration. The results show that estimating the amount of DP through MeOH concentration is associated with a probability of error of about 9% compared to estimating DP through 2-FAL concentration.

Paper turns yellow over time. Bleaching with oxidizing agents is one of the most common methods, which creates a colorless result by breaking down the light-absorbing chromophores. In this research, the changes in the properties of Paper by applying oxidizing agents are studied. The Paper samples were characterized by colorimetric, infrared spectroscopy, tensile, acidity, and SEM microscopes. Four oxidizing solutions were deployed for whitening the samples of Whatman Paper using the Immersion method, including Hydrogen Peroxide (2 % V/V), Sodium Peroxide (2 % W/V), Potassium Periodate (2 % W/V), and Potassium Persulphate (2 % W/V) all solved in distilled water. The samples were treated within 48 hours, and characterizing tests were deployed. The results show that hydrogen peroxide with the highest tensile strength (17. 75 Nm/g) and the lowest color difference (∆E= 1. 48) after accelerated aging has the best performance among other samples. Also, hydrogen peroxide can be improved tensile strength, increase brightness, reduce yellowing, cause fibers stability, and keep the Paper at an almost neutral acidity.

Aluminum alloys are one of the most attractive materials due to their high specific strength, low density, and very abundance reserves in the earth’s crust. Aerospace, automobile, building, and so on are some of the industrial fields where aluminum and its alloys are utilized. However, it has some disadvantages, namely softness, lower wear resistance and lower corrosion resistance, decreases the service life of machine components. An effective approach to defeat these above disadvantages is coating the aluminum components with alumina-based composites coatings. Among alumina-based composites coatings, Al2O3-ZrO2 system has demonstrated unique features. Micro Arc oxidation (MAO) technique was employed to grow zirconia–alumina porous layers. The layers were grown under alternative current in the electrolytes of ZrOCl2 salt. Considering XPS, XRD, and EDX results, the layers mainly consisted of a-Al2O3, g-Al2O3, monoclinic ZrO2, tetragonal ZrO2. Increasing the voltage resulted in higher zirconium concentration. AFM studies revealed that the surface roughness increased with voltage. Morphological evaluations, performed by SEM, showed that the microstructure of the layers strongly depended on the applied voltage.

The pulp and Paper industries are one of the largest water-consuming industries in the world. The high organic load of wastewater makes conventional treatment methods like biological and coagulation, ineffective for making the discharge effluent meet environmental standards. Advanced oxidation processes have been considered a promising solution due to their high oxidation power and low operating cost compared to other methods. These processes based on the type of radical production have different types, which are divided into two main categories of hydroxyl radicals and sulfate radicals, which are selected depending on the conditions and their purpose. In this research, by using the Response Surface Method (RSM) experiment design, sulfate radical efficiency, the initial oxidizing concentration and pH were optimized. To investigate the effect of factors, Chemical Oxygen Demand (COD) removal was measured at the end of each experiment as an index for organic pollutant removal. In the maximum state whit this method, 75% of the initial COD can be removed. In the economic optimal mode, with the initial dimensionless peroxy-disulfate dose = 0.407 and initial pH = 8.37, COD removal% = 53.53% is demonstrated.