(LUẬN văn THẠC sĩ) investigation on a combination of chemical and biological methods for the treatment of pulp and paper mill wastewater in vientiane

TECHNICAL UNIVERSITY OF DRESDEN VNU UNIVERSITY OF SCIENCE Vienglasy Mangnomek INVESTIGATION ON A COMBINATION OF CHEMICAL AND BIOLOGICAL METHODS FOR THE TREATMENT OF PULP AND PAPER MILL WASTEWATER IN VIENTIANE MASTER THESIS Hanoi, November 2011 i TIEU LUAN MOI download : skknchat@gmail.com TECHNICAL UNIVERSITY OF DRESDEN VNU UNIVERSITY OF SCIENCE Vienglasy Mangnomek INVESTIGATION ON A COMBINATION OF CHEMICAL AND BIOLOGICAL METHODS FOR THE TREATMENT OF PULP AND PAPER MILL WASTEWATER IN VIENTIANE Major: Waste Management and Contaminated Site Treatment MASTER THESIS SUPERVISOR: ASSOC PROF DR BUI DUY CAM ASSOC PROF DR DO QUANG TRUNG Hanoi, November 2011 ii TIEU LUAN MOI download : skknchat@gmail.com Table of contents Abbreviations iv List of tables v List of figures vi Abstracts vii Acknowledgement viii Introduction CHAPTER I LITERATURE STUDY 1.1.Status of environmental management in Vientiane 1.1.1 Introduction of Vientiane 1.1.2 Environmental issues in Vientiane 1.1.3 Situation of pulp and paper mill in Vientiane 1.2 The pulp and paper mill wastewater treatment technologies 11 1.2.1 Pulp and paper mill production 11 1.2.2 Sources of pollution in the production of pulp and paper mill 12 1.3 Some methods commonly using to treat with the wastewater 15 1.3.1 Physicochemical treatment 15 1.3.2 Membrane filtration 19 1.3.3 Biological treatment 21 CHAPTER II EXPERIMENT 25 2.1 Research objective 25 2.2 Equipment and Chemicals………………… ……………………………… 26 iii TIEU LUAN MOI download : skknchat@gmail.com 2.2.1 Equipments 26 2.2.2 Chemicals 26 2.3 Analitycal methods in the study 28 2.3.1 Determination of Chemical Oxygen Demand 28 2.3.2 Determination of Biochemical Oxygen Demand……………………… …29 2.3.3 Analysis of Ammonia content 30 2.3.4 Analysis of Nitrite and Nitrate 31 2.3.5 Procedure for the determination of Phosphate 33 2.4 Preparation of Pulp and paper mill samples 34 2.5 Physicochemical method for the pretreatment of pulp and paper mill wastewater……………………………………………………………………… 35 2.5.1 Coagulation experiments for sample and 35 2.5.2 Reduce of COD value by pH change for sample 35 2.6 Removal of COD in pulp and paper mill wastewater by combinated Aerobic and Anaerobic circulatory System ……………………………………………….35 2.7 Material filling in column 36 CHAPTER III RESULTS AND DISCUSSION 39 3.1 Pretreatment of pulp and paper mill wastewater by physicochemical methods39 3.1.1 Coagulation experiments for sample and 39 3.1.2 Effect of the pH and PAC doseage to the reduction of COD in sample 41 3.2 Investigation of the biological treatment with activated sludge 43 3.2.1 Effect of retention time on COD removal for sample 43 3.2.2 Effect of retention time on COD removal for sample 2………………… 44 3.2.3 Effect of retention time on COD removal for sample ………….……….45 3.3 Primary investigation on the treatment of pulp and paper mill wastewater by the combination of circulatory aerobic and anaerobic system 46 iv TIEU LUAN MOI download : skknchat@gmail.com 3.3.1 The reduction of COD 47 3.3.2 The change of Ammonia 48 3.3.3 The change of Nitrite 49 3.3.4 The change of Nitrate…………………………………………………… 50 3.3.5 The change of Phosphrus 51 3.3.6 A proposed model for pulp and paper mill wastewater treatment for Vientaine factories 52 Conclusions 54 References ……………………………………………………………………….55 v TIEU LUAN MOI download : skknchat@gmail.com Abbreviations AC Anaerobic Contact process AF Anaerobic Filter AOX Adsorbable organic halogens BOD Biological Oxygen Demand COD Chemical Oxygen Demand CSOCA&A Circulatory system of combination of Aerobic and Anaerobic DO Dissolved Oxygen MLSS Mixed Liquor Suspended Solids PAC Poly Aluminum Chloride TSS Total suspended solids vi TIEU LUAN MOI download : skknchat@gmail.com List of tables Table Wastewater Quality in Vientiane Capital Jan-Dec 2000[2]………… …5 Table Industrial Growth in Lao PDR [2]………………………………… ……6 Table 3.Pollutants in the wastewater in the factory’s ponds[8]………………… Table Typical efficiencies of aerobic systems [9]…………………………… 22 Table Anaerobic degradability of pulp and paper mill wastewater[19]… … 23 Table Data of standard curve 30 Table Data of ammonia standard curve……………………………………….32 Table Data of nitrite standard curve making………………………………… 33 Table Data of nitrate standard curve……………………………………… …34 Table 10 Data of phosphorus standard curve………………………………… 35 Table 11 Effect of PAC dosage to COD reduction for sample 1…………….….41 Table 12 Effection of coagulant PAC to COD removal …………………… …42 Table 13 Effection of pH changed to COD removal……………………………44 Table 14 Effection of coagulant PAC to COD removal ……………………… 44 Table 15 Data of effection of aerobic to COD removal ……………………… 46 Table 16 Data of effection of aerobic to COD removal…………………………47 Table 17 Data of effection of aerobic to COD removal…………………………48 Table 18 Data of effection of CSOCA&A to COD removal…………………….49 Table 19 Data of effection of CSOCA&A to NH4+ due to times……………… 51 Table 20 Data of effection of CSOCA&A to NO22- due to times……………… 51 Table 21 Data of effection of CSOCA&A to Nitrate due to times………………52 vii TIEU LUAN MOI download : skknchat@gmail.com Table 22 Data of effection of CSOCA&A to Phosphorus due to times……… 53 List of figures Figure Map of Lao PDR………………………………………………… ….2 Figure2 Source flowchart from the production line in KPS paper mill in Laos [8]………………………………………………………………….……… 10 Figure Process description for pulp and paper mill factory[10]………….… 12 Figure Pollutants from various sources of pulping and papermaking [11]…………………………………………………………………………….….15 Figure Diagram of Flocculate w11………………………………………… 27 Figure Diagram of Aerobic system W11………………………………………27 Fignure COD standard curve 30 Figure Ammonia standard curve…………………………………….……… 32 Figure Nitrite standard curve……………………………………………… …33 Figure 10 Nitrate standard curve………………………………………….…… 34 Figure 11 Phosphorus standard curve……………………….…………….…….35 Figure12 Diagram of combining Anaerobic and Aerobic system………… … 38 Figure 13 : Surface of porous material………………………………………… 39 Figure14 Microorganism layer……………………………………………… …38 Figure 15 Membrane of porous material after three times circularly pumping water containing nutrient……………………………………………………… 38 Figure 16 Diagram of effection of PAC dosage to COD removal………… …38 Figure 17 Diagram of effection of coagulant PAC to COD removal…………….41 Figure 18 Diagram of effection of pH changed to COD removal… 42 Figure 19 Diagram of effection of coagulant PAC to COD removal………… 43 viii TIEU LUAN MOI download : skknchat@gmail.com Figure 20 Diagram of effection of aerobic to COD removal…………….… … 44 Figure 21 Diagram of effection of aerobic to COD removal……………….……45 Figure 22 Diagram of effection of aerobic to COD removal……………….……46 Figure 23 Diagram of effection of aerobic to COD………………………… …48 Figure 24 Diagram of effection of aerobic to Ammonia………………….…… 49 Figure 25 Diagram of effection of aerobic to Nitrite………………………… 50 Figure 26 Diagram of effection of aerobic to Nitrate……………………………51 Figure 27 Diagram of effection of aerobic to Phosphrus…………………… …51 Figure 28 : A purposed model wastewater treatment process using activated sludge…………………………………………………………………….…… 54 ix TIEU LUAN MOI download : skknchat@gmail.com Abstract Lao PDR is a country rich in natural resources and its water resources are vital in providing the basic needs for its people, socio-economic development of the country The scale and extent of environment problems in the urban areas of Vientiane is relatively small compared to other cities in the region due to its relatively small size and population, low population density, and relatively low level of industrial activity However, there are some water pollution problems in major urban areas caused by various water uses by communities (households, hotels, hospitals and entertainment centers) In addition, the actions of the agricultural and industrial sectors have resulted in water pollution, including mineral exploitation, pulp and paper mills factories and hydropower generation Therefore, in accordance with the Millennium Development Goals, the government set targets in order to improve the local people’s access to safe drinking water by the years 2015 For in Vientiane is one looking for manage methods for treatment wastewater discharges In this study, the situation of environmental pollution in Vientiane in general and from the pulp and paper mill wastewater in particularly was evaluated These are recognized that the environmental issues in Vientiane having problem The wastewater samples were collected from pulp and paper mill factories in Laos and Vietnam for the experiments in laboratory of Environmental Chemistry, Hanoi University of Science The physicochemical and biological methods for the treatment of wastewater were investigated The results shown that, the pulp and paper mill wastewater can be pretreated by the reduction of pH with dilute H2SO4 acid at pH = 3; and by the coagulation with poly aluminum chloride (PAC) The COD removal from 74.21% of sample and 62.16% of sample Then the wastewater samples can be treated by using combined aerobic and anaerobic system with efficiency of COD removal 94.99% of anaerobic and 90% for aerobic x TIEU LUAN MOI download : skknchat@gmail.com adding PAC over mL, the line graph tented to go down However, the trend fluctuated slightly, nearly 1%, so we could consider as a stable trend The optimal dosage of PAC is mL of 10% solution per 100 mL of wastewater, or 2000 mg PAC per liter of wastewater After using PAC with volume of 2.0 mL, COD was decreased to 503.11 mg/L Table 12 Effect of PAC dosage on COD removal for sample VPAC(mL) 1.0 1.5 2.0 2.5 COD (mg/L) 2140 566.01 515.53 503.11 506.07 Removal Efficiency (%) 73.55 75.90 76.49 76.35 3.5 4.0 4.5 5.0 VPAC(mL) 3.0 506.07 506.07 518.69 512.38 515.53 Removal Efficiency (%) 76.35 76.35 75.76 76.05 75.91 COD removal(%) COD (mg/L) 77 76.5 76 75.5 75 74.5 74 73.5 73 VPAC(mL) Figure 17 Diagram of effect of PAC dosage on COD removal 3.1.2 Effect of the pH and PAC dosage on the reduction of COD in sample 3.1.2.1 Effect of the pH to the reduction of COD The sample had initial black color, pH value of 13.5 and COD value of 161740.36 mg/L Firstly, sample was diluted to the COD value of 6469.61 mg/L This solution was used to investigate the effect of pH on the reduction of COD content in the solution Diluted sulfuric acid solution was added to three wastewater samples to reduce the pH of solution, stirred in 2-3 minutes at 40 rpm and settled for hours The solution was separated into two phases; the liquid phase was taken to determine the COD value The results of experiments are shown in table 13 and figure 18 The diagram shows that, at pH = 2, the COD removal efficiency is the highest and attained 62.16% However, at pH of 3, the COD removal was lower 0.15% (62.01%) than at pH of 2; therefore the pH of was selected for the next experiments xlvi TIEU LUAN MOI download : skknchat@gmail.com Table 13 Effect of pH on COD removal pH COD (mg/L) 2507.62 2448.1 2457.8 61.24 62.16 62.01 Efficiency (%) 62.5 COD removal(%) 62 61.5 61 60.5 60 59.5 59 0.5 1.5 pH 2.5 3.5 Figure 18 Diagram of effect of pH on COD removal 3.1.2.2 Effect of the PAC dosage to the reduction of COD After pretreatment by adjusting the pH to 3, the COD value was 2457.8 mg/L and the sample was taken to the next step of coagulation by PAC The experiments were carried out as follows: six samples were adjusted to the pH of 6, then added 0.5 to 3.0 ml of 10% PAC solution, stirred for 15 minutes at 40 rpm and settled in 30 minutes The results are showed in table 14 and figure 18 The optimal dosage was 2ml of 10% PAC solution Table 14 Effect of coagulant PAC on COD removal VPAC(mL) 0.5 1.0 1.5 2.0 2.5 3.0 COD (mg/L) 2457.8 941.17 1024.00 995.33 922.06 931.61 934.79 61.55 58.17 59.34 62.33 61.94 61.82 Efficiency (%) xlvii TIEU LUAN MOI download : skknchat@gmail.com 64 COD removal(%) 62 60 58 56 54 52 50 0.5 1.5 VPAC(mL) 2.5 3.5 Figure 19 Diagram of effect of coagulant PAC on COD removal According to the diagram above, when added PAC with the volume of 2mL, the highest COD removal gained is 62.33% Thus, the volume of PAC solution is chosen at 2mL to be the optimal condition for coagulation method When adding PAC over 2mL, the line graph tented to go down However, the trend fluctuated slightly, nearly 1%, so we could consider as a stable trend Similar to sample and 2, the optimal dosage of PAC to the COD removal of sample is 2000mg PAC/ L 3.2 Investigation of the biological treatment with activated sludge 3.2.1 Effect of retention time on COD removal for sample After pretreatment with coagulation process, the COD value of sample was 846.76 mg/L and the value gained after days of BOD or BOD5 was 450.00 mg/L As a result, the ratio BOD/COD was 0.53 This ratio was rather suitable for using aerobic treatment The table 15 below showed the COD removal efficiency versus retention time of treatment Table 15 Data of effect of retention time on COD removal Time (Hour) COD(mg/L) 846.76 624.57 540.57 303.49 Removal Efficiency (%) 26.24 36.16 64.16 Time COD (mg/L) 268.84 244.21 234.30 199.66 Removal Efficiency (%) 68.25 71.16 72.33 76.42 xlviii TIEU LUAN MOI download : skknchat@gmail.com COD removal (%) 90 80 70 60 50 40 30 20 10 0 Time (hours) Figure 20 Diagram of effect of retention time on COD removal The line graph of diagram above indicated the trend of treatment, the COD removal went up during the time of reaction At the time of t = hours the COD value tested was 199.66 mg/L The wastewater sample should go to further treatment 3.2.2 Effect of retention time on COD removal for sample The COD value of sample after coagulation step was 503.11mg/L After days, BOD5 gained the result of 297.00 mg/L The BOD/COD (297 / 503.11) ratio was 0.59; therefore it was suitable for applying aerobic treatment to this sample (according to Rodriguez et al (2007)) The effect of retention time on COD removal of sample is shown in table 16 and figure 21 Table 16 Data of effect of retention time to COD removal Time (hours) COD (mg/L) 503.11 468.22 310.49 209.54 121.21 80.20 48.66 8.05 39.02 58.85 76.19 84.24 90 Removal Efficiency (%) xlix TIEU LUAN MOI download : skknchat@gmail.com 100 90 COD removal(%) 80 70 60 50 40 30 20 10 0 Time (hours) Figure 21 Diagram of effect retention time on COD removal The line graph of diagram above indicated the trend of treatment; COD removal went up during the time remaining reaction After hours, the COD value tested was 48.66 mg/L The color, the COD value and the pH of have met the standard to release to the environment (according to Lao and Vietnam industrial wastewater quality 2005) 3.2.3 Effect of retention time on COD removal for sample In order to compare the COD removal efficiency by activated sludge process with two samples from Laos, the experiments of sample were carried out and the results are shown in table 17 and figure 22 l TIEU LUAN MOI download : skknchat@gmail.com Table 17 Data of effect of aerobic on COD removal Time ( hours) 922.2 884.92 878.7 580.47 561.83 555.62 543.19 Efficiency (%) 4.04 4.71 37.05 39.07 39.75 41.09 Time 10 11 12 - COD (mg/L) 524.55 518.34 437.57 418.93 363.93 338.15 - Efficiency (%) 43.12 43.79 52.55 54.57 60.63 63.33 - COD (mg/L) ( hours) COD removal(%) 100 80 60 40 20 0 10 20 30 40 50 60 time( hours) Figure 22 Diagram of effect of aerobic on COD removal At the time of hours the COD value was 524.55mg/L The wastewater sample should go to further treatment methods 3.3 Primary investigation on the treatment of pulp and paper mill wastewater by the combination of circulatory aerobic and anaerobic system The wastewater sample after pretreatment by pH change and coagulation in the above experiments (3.1.2.2) getting COD value of 922.2mg/L was used to test the treatment efficiency by circulatory aerobic and anaerobic system 60 liters of wastewater were adjusted to pH of 7-8 and pumped to the first column which is filled with porous film The organic compounds were degraded by the microorganisms living in the porous film The analytical samples were taken and determined the values of COD, NH4, NO2-, NO3-, and PO43- 3.3.1 The reduction of COD The results showed that after 57 hours the COD removal was 94.99% which reduced COD value from 922.20 mg/L to 46.2 mg/L The gained COD value was good for outflow standard li TIEU LUAN MOI download : skknchat@gmail.com When comparing aerobic using alone with the circulatory system of combination of aerobic and anaerobic (CSOCA&A), it is clear that, the CSOCA&A gained the higher efficiency (94.99%) than aerobic system (90%) In anaerobic column, without oxygen, the persistent organic chemicals were broken down to other chemicals forms which are then easy to treat by aerobic method Table 18 Data of effect of CSOCA&A on COD removal Time (hours) 24 25 26 28 COD (mg/L) 922.22 915.98 829.01 505.91 487.27 481.06 462.42 Efficiency (%) 4.04 4.71 45.47 47.16 47.83 49.85 Time ( hours) 29 31 46 47 56 57 - COD (mg/L) 462.42 394.07 300.88 288.45 52.45 46.13 - Efficiency 49.85 57.26 67.37 68.72 94.32 94.99 - COD removal(%) (%) 100 90 80 70 60 50 40 30 20 10 0 10 20 30 40 50 60 time( hours) Figure 23 Diagram of effect of aerobic to COD 3.3.2 The change of ammonia concentration lii TIEU LUAN MOI download : skknchat@gmail.com Monitoring the change of ammonia concentration, it was seen that ammonia reduced to 3.02 mg/L after 57 hours treated by CSOCA&A This is suitable for the output standard required Table 19 Data of effect of CSOCA&A to NH4+ due to time Time( hour) 24 25 26 NH4+concentration(mg/L) 13.30 11.50 8.23 6.69 5.73 5.54 Time( hour) 28 46 47 56 57 - NH4 concentration(mg/L) 5.41 3.17 3.12 3.16 3.02 - + Amonia Concentration(mg/L) 14 12 10 0 10 20 30 40 50 time( hour) Figure 24 Diagram of effect of aerobic to Ammonia 3.3.3 The change of nitrite concentration Nitrite and nitrate concentrations were also measured to determine the amount of nitrogen and how nitrogen compounds work under CSOCA&A Over hours, the diagram reached the highest peak with the value of 12.46 mg/L of nitrite The reduction over 46 hours was 94.6% Table 20 Data of effect of CSOCA&A on NO2- due to time Time(hours) NO2 9.46 12.09 24 25 26 28 29 31 4.71 2.62 1.61 1.36 1.17 0.97 46 - Concentration (mg/L) 10.47 liii TIEU LUAN MOI download : skknchat@gmail.com 0.51 Nitrite Concentration(mg/L) 14 12 10 0 10 20 30 40 50 Time( hours) Figure 25 Diagram of effect of aerobic on Nitrite concentration 3.3.4 The change of nitrate concentration Over 46 hours the nitrate reduction was 77.4% and the output standard for nitrate was hopeful to release Table 21 Data of effect of CSOCA&A on Nitrate due to time Time(hours) 24 25 Concentration Nitrate(mg/L) 7.89 4.31 2.42 2.13 2.23 Time(hours) 26 28 29 31 46 Concentration Nitrate(mg/L) 2.10 2.06 2.01 2.07 1.78 20 Time(hour) 30 Nitrate Concentration(mg/L) 0 10 40 50 Figure 26 Diagram of effect of aerobic on Nitrate 3.3.5 The change of phosphorus concentration liv TIEU LUAN MOI download : skknchat@gmail.com The amount of phosphorus over 46 hours was reduced from 23.10 mg/L to 9.3 mg/L This concentration has met the standard to release to the environment (wastewater discharge standard 2005 VN) Table 22 Data of effect of CSOCA&A on phosphorus due to time Time (hours) 24 25 Phosphorus Concentration (mg/L) 23.10 21.74 17.71 14.37 14.37 Time (hours) 26 28 29 31 46 Phosphorus Concentration (mg/L) 14.21 14.07 13.39 13.15 9.31 25 Phosphorus Concentration(mg/L) 20 15 10 0 10 20 30 40 50 Time( hours) Figure 27 Diagram of effect of aerobic on phosphorus From the results of COD values and sum amount of nitrogen and phosphorus concentration it is possible to conclude that the quality of effluent after treatment is suitable to release into the environment (according to Lao and Vietnam industrial wastewater quality standard 2005) 3.3.6 A proposed model for pulp and paper mill wastewater treatment for Vientiane factories From the experimental results above, a model for pulp and paper mill wastewater treatment of Vientiane factories was proposed as in figure 28 Firstly, pulp and paper mill wastewater is equalized and diluted to suitable conditions, then the pH of solution is adjusted to by diluted sulfuric acid The sludge is converted to solid form for further treatment The liquid phase is adjusted to the pH of and coagulated by 10% PAC solution to remove suspended matters and also reduce COD The sludge of this stage also goes to solid form for further treatment and the liquid phase comes to the next treatment lv TIEU LUAN MOI download : skknchat@gmail.com step Finally, all so used above wastewater samples were pumped to combined anaerobic and aerobic system Pulp and paper mill wastewater H2 SO4 Equalization Sludge Precipitation (pH=3) Sludge press Wastewater Solid waste PAC Coagulation (pH=6) Sludge press Solid waste Wastewater Aerobic Anaerobic Figure 28 A proposed models for pulp and paper mill wastewater treatment system Discharge Vientiane factories lvi TIEU LUAN MOI download : skknchat@gmail.com for Conclusions During the time of doing master thesis at Lab of Environmental Chemistry, Hanoi University of Science I have some conclusions as follows: The current environmental issues in Vientiane in general and the pulp and paper mill wastewater in particularly were evaluated It is obvious that the environmental issues in Vientiane are becoming serious and urgently require the attention of the government as well as relative agencies The selected analytical methods are suitable for monitoring the value of COD, BOD and NH4+, NO2-, NO3-, PO43- contents in pulp and paper mill wastewater in Vientiane The application of physicochemical method to pretreat pulp and paper mill wastewater by adjusting the pH value to and coagulating high suspended solids with 10% PAC solution is suitable for tissues paper factory in Vientiane The preliminary results of using the combined Aerobic and Anaerobic circulatory system for the pretreatment of pulp and paper mill wastewater have shown that the combined system gets higher efficiency of COD removal (94.99%) and than the aerobic one (90%) A model for the wastewater management of pulp and paper mill industry in Vientiane is proposed and will be evaluated for further application lvii TIEU LUAN MOI download : skknchat@gmail.com References [1] Environmental protection law (1999), Lao people’s democratic republic, 20, 10- 16 [2] Lao PDR Environment Monitoring (2005), 67, viii - ix [3] National water resources profile (June 2008), Department of Water Resources and Environment Administration (WREA), 81, 47- 66 [4] Mekong River Commission (2010), The Mekong River Report Card On Water Quality, Assessment of potential Human Impacts on Mekong River Water Quality, 1-16 [5] Souphasay Komany (2009), Water Environment Partnership in Asia(WEPA) Outlook of Water Environmental Management Strategies in Asia, Ministry of Environment Japan, 341-68 [6] Government Counterpart Agency: Ministry of Industry and Handicrafts (2003), Lao PDR: Medium-term Strategy and Action Plan for Industrial Development Final Report, UNIDO INTEGRATED PROGRAMME FOR LAO PDR, 11 1-140 [7] Japan International Cooperation Agency(JICA), Public Works and Transport Institute(PTI),Ministry of public Works and transport(MPWT), Lao People’s Democratic Republic ( 2009), The study on improvement of water environment in Vientiane city, Progress report (1) 134, 81-82 [8] Kaisorn Thanthathep, Phousavanh Douangphila, Somphone Kkhamphanh (2009), An Assessment of paper mill wastewater impacts and treatment options in Vientiane Capital City, Lao P.D.R, Economy and Environment Program for Southeast Asia, 27 1-15 [9] D.Pokhrel, T Viraraghavan (2004), Treatment of pulp and paper mill wastewater-a review,Science of the Total Environment 333, 37 – 58 [10] G Thompson, J Swain, M Kay, C.F Forster (2000), The treatment of pulp and paper mill effluent: a review, Bioresource Technology, 77, 275 – 286 [11] Tiina Leiviska , Jaakko Ramo, Hannu Nurmesniemic, Risto Poykio, Toivo Kuokkanene ( 2009 ), Size fractionation of wood extractives, lignin and trace elements in pulp and paper mill wastewater before and after biological treatment, water research, 433 199 – 3206 [12] A Helbe,W Schlave, P Andr, R Jenny, C Mobius(1999), Advanced effluent treatmentin the pulp and paper industry with a combined process of ozonation and fixed bed biofilm reactors, Water Science and Technology 40 343–350 [13] W De los Santos Ramosa,T.Poznyaka, I Chairezb, I Córdova R (2009), Remediation of lignin and its derivatives from pulp and paper industry wastewater by the combination of chemical precipitation and ozonation, Journal of Hazardous Materials 429, 428-434 [14] Tiina Leiviska, Jaakko Ramo, Hannu Nurmesniemic, Risto Poykio, Toivo Kuokkanene( 2009 ), Size fractionation of wood extractives, lignin and trace elements in pulp and paper mill wastewater before and after biological treatment, water research 43 3199-3206 [15] I Akmehmet Balcıoglua,E Tarlanb, C Kıvılcımdanc,M.Turker Sacan (2006), Merits of ozonation and catalytic ozonation pre-treatment in the algal treatment of pulp and paper mill effluents, Journal of Environmental Management 85, 918–926 lviii TIEU LUAN MOI download : skknchat@gmail.com [16] A Kostamo, B Holmbom, J.V.K Kukkonen (2004), Fate of wood extractives in wastewater treatment plants at kraft pulp mills and mechanical pulp mills, Water Research 38, 972–982 [17] A.L Ahmad, S.S Wong, T.T Teng, A Zuhairi (2007), Improvement of alum and PACl coagulation by polyacrylamides(PAMs) for the treatment of pulp and paper mill wastewater, Chemical Engineering Journal 137, 510–517 [18] Angela Claudia Rodrigues, Marcela Boroski, Natalia Sueme Shimada, juliana Carla Garcia, Jorge Nozaki, Noboru Hioka (2007),Treatment of pulp and paper mill wastewater by coagulation-flocculation followed by heterogenous photocatalysis, Journal of Photochemistry and Photobiology 194, 1-10 [19] M.Sarioglu (2005), Removal of ammonium of municipal wastewater using natural Turkish (Dogantepe) zeolite, Separation and purification Technology 1-11 [20] Kati Eskelinen, Heikki Särkkä (2010), Removal of recalcitrant contaminants from bleaching effluents in pulp and paper mills using ultrasonic irradiation and Fenton-like oxidation, electrochemical treatment, and/or chemical precipitation: A comparative study, Desalination 255, 179–187 [21] Yadav B.R & Gaarg A(2011), Treatment of pulp and paper mill effluent using Physico-Chemical Processes,IPPTA 155-160 [22] N Kaushalya Herath, Yoshito Ohtan, Hideaki Ichiura (2011) , Color and phenolic compounds reduction of Kraft Pulp Mill effluent by ozonation with some pretreatments, AMERICAN JOURNAL OF SCIENTIFIC AND INDUSTRIAL RESEARCH800 798806 [23] Z Beril Gonder, Semiha Arayici, Hulusi Barlas (2010), Advanced Treatment of Pulp and Paper Mill Wastewater by Nanofiltration Process: Effects of Operating Conditions on Membrane Fouling,Separation and Purification Technology 50 1- [24]E.Dialynas,E.Diamadopoulos (2007),Integration of immersed membrane ultration with coagulation and activated carbon adsorption for advanced treatment of municipal wastewater,Desalination 230,113-127 [25] Yuzhong Zhanga,Chunming Maa,Feng Yeb,Ying Konga,Hong Li(2009),The treatment of wastewater of paper mill with integrated membrane process, Desalination 236 349–356 [26] Ulas Tezel,Engin Guven,Tuba H Erguder,Goksel N Demirer(2001) , Sequential (anaerobic/aerobic) biological treatment of Dalaman SEKA Pulp and Paper Industry effluent, Waste Management 21 717–724 [27] Jukka A.Rintala & Jaakko A Puhakka(1994),Anaerobic treatment in pulpand paper mill waste management: Areview, Bioresource Technology 47,1-14 [28] Tomas Alexadersson (2003),Water Reuse in Paper Mills Measurements ans Control Problems in Biological Treatment, Department of Industrial Electrical Engineering and Automatio Lund University 119, 38-39 [29] K.V.Raajeshwari, M.Balakrishnan, A.Kansal, Kusum Lata, V.V.N.Kishore (2000),State of the art of anaerobic digestion technology for industrial wastewater treatment, Renewable and Sustainable Energy Reviews 135-156 [30] Jack R Stabley, Raymond M.Stewart, Tablec International Relative Atomic Weights, 500-516, 508 lix TIEU LUAN MOI download : skknchat@gmail.com [31] Lenore S.Clesceri, Arnold E.Greenberg, Andrew D.Eaton (20th Edition), Standard Method for the Examination of Water and wastewater, 364 4000 – 6000 lx TIEU LUAN MOI download : skknchat@gmail.com ... further treatment methods 3.3 Primary investigation on the treatment of pulp and paper mill wastewater by the combination of circulatory aerobic and anaerobic system The wastewater sample after... environmental issues in Vientaine in general and the pulp and paper mill wastewater in particularly b) To identify and evaluate the analitycal methods which are suitable for the monitoring and control... wastewater treatment The amount and characteristics of the pulp and paper mill wastewater depend highly on raw materials and processing conditions The pulp and paper mill wastewater may cause oxygen