Luận văn investigation on a combination of chemical and biological methods for the treatment of pulp and paper mill wastewater in vientiane

For the wastewater sample 2 taken from tissues paper factory in Vientiane, the coagulation and follwing by biological treatment with activated sludge are suitable methods Acknowledgement

TECHNICAL UNIVERSITY OF DRESDEN YNU UNIVERSITY OF SCIENCE

Vienglasy Mangnomek

INVESTIGATION ON A COMBINATION OF CHEMICAL AND

BIOLOGICAL METIIODS FOR TIT TREATMENT OF PULP AND

PAPER MILL WASTEWATER IN VIENTIANE

MASTER THESIS

Hanoi, November 2011

TECHNICAL UNIVERSITY OF DRESDEN: NU 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 111¿/518

SUPERVISOR: ASSOC PROF DR BUI DUY CAM

ASSOC PROF, DR DO QUANG TRUNG

Hanoi, November 2011

1.1.3 Sieuation of pulp and paper mill in Vientiane 7

1.2 The pulp and paper mill wastewater treatment technologies - 11

1.2.1, Pulp and paper mill production

1.2.2 Sources of pollution in the production of pulp and paper mill

1.3 Some methods commonly using to treat with the wastewater - 15

2.31 Bquipments - - - 26

2.3.1, Determination of Chemical Oxygen Demand - 28 2.3.2, Determination of Biochemical Oxygen Demand 29

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

2.5.1, Coapulation experiments for sample 1 and 2 Bl tr ip - - 35

2.5.2, Reduce of COD value by pH change for sample 3

2.6 Removal of COD in pulp and papor mill waslewaler by combinated Acrabic

CHAPTHR HI, RKHSULTS AND DISCUSSION

3.1 Pretreatinent of pulp andl paper mill wastewaler by pliysicochermical methods39

3.1.1, Coagulation experiments for sample 1 and 2 - - 39

3.1.2 Effect of the pH and PAC doseage to the reduction of COD in sample 3 41 3.3 Tnvesligalion of the biological ireatrnent with aclivated sludge 43

3.2.1 Effect of retention time on COD removal for sample 1 - 4

3.2.2 Hffect of retention time on COD removal for sample 2 weed

3.2.3 Effect of retention time on COD removal for sample 3 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

3.3.1 The ređuction of COD - - Aq

3.3.3 The change of Nitrite do 3.3.4 The change of Nitrate 50

3.3.5 ‘The change of Phosphrus

Abbreviations

AC Anaerobic Contact process

AOX Adsorbable organic halogens

CSOCA&A Circulatory system of combination of Aerobic and Anaerobic

MLSS Mixed Liquor Suspended Solids

PAC Poly Aluminum Chloride

TSS Total suspended solids

List of tables

Table 1 Wastewater Quality in Vientiane Capital Jan-Dec 2000[2]

Table 2 Industrial Growth in Lao PDR [2]

Table 3.Pollutants in the wastewater in the factory’s ponds[8]

Table 4 Typical efficiencies of aerobic systems [9]

Table 5 Anaerobic degradability of pulp and paper mill wastewater[19]

Table 6 Data of standard curve - - as

Table 7 Data of ammonia standard curve

Table 8 Data of mitrite standard curve making

Table 9 Data of nitrate standard curve

Table 10 Data of phosphorus standard curve

Table 11 Effect of PAC dosage to COD reduction for sample 1

Table 12 Effection of coagulant PAC to COD removal

Table 13 Effection of pH changed to COD removal

Table 14 Effection of coagulant PAC to COD removal

Table 15 Data of effection of aerobic to COD removal

Table 18, Data of effection of CSOCA&A to COD removal

Table 19 Data of effection of CSOCA&A to NH," due to times

Table 20 Data of effection of CSOCA&A to NO,” due to times

Table 21 Data of effection of CSOCAGA to Nitrate due to times

vii

Table 22 Data of effection of CSOCA&A to Phosphorus due to times .53

List of figures

Figue 1 Map of Lao PDR s22 2222022252222 2221155 se2

Figure2 Source flowchart from the production line in KPS paper mill in

Figure 3 Process description for pulp and paper mill factory[10] 12

Figure 5 Diagram ofElocculate w11 cóc s2 Figure 6 Diagram of Aerobic system W11 cue 27

Ripniits 7.- COD standard Giry 6 jssccceenecconsiontnenmonteennanentoeen 30

Figure 8 Ammonia standard curve Rete Mee

Figure 10 Nitrate standard curve xiàšocšilg42gZ08E š wenn

Figurel2 Diagram of combining Anaerobic and Aerobic system eae R Figure 13 : Surface of porous materiaL 2c se tesco vee 639) Figurel4 Microorganism layer "— see ees eteneeerets erties teense 38

Figure 15 Membrane of porous material after three times circularly pumping

Figure 16 Diagram of effection of PAC dosage to COD removal 38

Figure 17 Diagram of effection of coagulant PAC to COD removal AI 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

Figure 20 Diagram of effection of aerobic to COD removal

Figure 21 Diagram of effection of aerobic to COD removal

Figure 22 Diagram of effection of aerobic to COD removal

Figure 23 Diagram of effection of aerobic to COD

Figure 24 Diagram of effection of aerobic to Ammonia

Figure 25 Diagram of effection of aerobic to Nitrite Figure 26 Diagram of effection of aerobic to Nitrate

Figure 27 Diagram of effection of aerobic to Phosphrus 51

Figure 28 : A purposed model wastewater treatment process using activated „54 sludge

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 counby 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 sive and population, low population density, and relatively low

level of industrial activity However, there are some water pollution problems in

major urban arcas caused by various waler uses by commnuniies (houscholds,

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, m accordance with the Miullenmum Development Goals, the

government set targets in order to improve the local people’s access to safe drinking water by the years 2015 Vor in Vientiane is one looking for manage methods for treatment wastewater discharges

Jn 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 Invironmental Chemistry, Hanoi University of Science The physicochemical and biological methods for the treatment of wastewater were investigated The resulis shown that, the pulp and paper mill wastewater can be pretreated by the reduction of pI with dilute II,SO, acid at pHi = 3; and by the coagulation with poly alumimumn chloride (PAC) The

COD removal from 74.21% of sample 1 and 62.16% of sample 3 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

alone the reduction of the COD For the wastewater sample 2 (taken from tissues paper factory in Vientiane), the coagulation and follwing by biological treatment with activated sludge are suitable methods

Acknowledgement The time of doing thesis in HUS is very special to me It is the time for to harvest my knowledge and lo mel inleresting Vietnamese friends Thank you for accepting the long hours, weekends and holidays 1 have spent working, for taking, good varc of me during this time and for pushing just hard cnough to make sure I finally completed my thesis

1 would like to express my ubmost appreciation and thanks lo Prof Dr Bui Duy Cam and Assoc Prof Dr Do Quang Trung for them valuable guidance, endurance, encouragement and support throughout this research

Several people have given me assistance with the work in this thesis I

thank Mr Mai Xuan Thang and the lale Mrs Hoang Thu Trang for assistance in

the laboratory, and for assistance wilh the experimental set up

Special thanks are extending to Prof Berd Bilitewski, Prof Nguyen Thi

Diem Trang for your role in this circumstance

Finally, the generous financial support by the DAAD Also the support of

the Hanoi University of Science and Dresden University of ‘Technology is acknowledged

Introduction

‘Water are vital element for both of demand’s people and socio-economic

development of the country As the population has grown, demand is also increscd and has had to travel further in scarch of good quality water, marginal and pollut:

have started being lapped Therefore, investigation of the water quality in Vientaine is

sourecs

very important because ILaos is ane of developing comniry looking for the suitable system

for wastewaler treatment

“rhe amount and characteristies of the pulp and paper mill wastewater depend

highly on raw materials and processing conditions, ‘the pulp and paper mill wastewater

may cause oxygen deficiency, acute or chronic toxicity, mutagenicity in recipient water

bodies In some countries the discharge standands for pulp and paper mills include

conventional biochemical oxygen demand (BOD), chemical oxygen demand (COD) and

Las adsorbabte

suspended solide also mutstenis and organochlorine compounds expr

organic halide (AON) There are number of Lectmigne to reduec the discharged pulp and paper milf wastewaler The mechanical trealment method with primary dlariic

usually applied to remove the wastewater solids and the organic load while dissolved organics are removed in aerated lagoons and/or activated sludge system, the most commonly

applied biological processes Llowever, these processes are expensive and none is

consider to be economically viable when this is done as standard process Biological

method have been found to be more effective and eco-friendly since they are capable of degrading not only lignin but also chloro-oganics contributing to AOX,

In my study, the overview of the wastewater treatment technologies for pulp and paper mill factories are conducted for the purpose of applying to Laos and both methods

af chemical and biclogical ones arc investigated for the treatment of pulp and paper mill wastewaler in Vientiane The rcal samples frorn Laos, Vietnam pulp and paper mill

wastewater have been tested

CHAPTER L LITERATURE STUDY 1.1 Status of environmental management in Vientiane

1.1.1 Introduction of Vientiane

“The Lao People’s Democratic Republic (Lao PDR) is near to Myanmar,

Cambodia, the People’s Republic of China , Thailand, and Viet Nam The total land area

of the country is 236,800 square kilometers (km?) with a largely mountainous

topography The capital, Vientiane (See picture 1 - Map of Lao PDR), however lies ona plain The country is bordered on the west by the Mekong River, making the river an

important artery for transportation, communications, and trade with other countries

sharing tributaries of the Mekong River

Set in the heart of Vientiane, Laos from the north latitude 17 45'50 - 22'38 18

09'37 5'40 and 102 - 103 east longitude and the natural area 3.920 km Vientiane is the 9

District: Chanthabuly, Sikottabong, Xaysettha, Sisattanak, Naxaythong, Saythany,

Hatsaiphong, Saengthong Phakngum area and population density level of economic

development of each district is different Entire Vientiane has 500 villages, of which

urban area accounts for 76% of villages, rural areas account for only 24%, Population Vientiane has highest level of culture, a spirit of hard-working, patriotic tradition and

unyielding will to revolution [1]

Figure 1 Map of Lao PDR Lao PDR is a rich country in natural resources and its water resources are vital in providing the basic needs for its people, for socio-economic development of the country

and for the ecological systems The availability of water resources has created favourable

conditions for the Laos and for the socio-economic development of the country, but it is essential that the country protects and manages water and water resources in a sustainable way Despite this a scarcity of water for both drinking and imgation purposes is common

in some provinces particularly in remote areas As the population has grown, and has had

to travel further in search of good quality water, marginal and polluted sources have

started being tapped, The major surface water resources are from rivers, streams and via

gravity fed systems and through the protection of spring water Groundwater is sourced

1.1.2 Environmental issues in Vientiane

“rhe scale and extent of environment problems in the wan 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, despite recent investments, there remain few systems in place to ensure that all, and in particular the poor, benefit from environmental improvements and environmental problems can be controlled in the future (EPL, 1999),

The Watcr Quality Laboratory of the Ministry of Agriculture and Forestry

reported that the quality of watcr in Lao PDR has generally been good according to the past 15 years of monitoring data, Tlowever, there are some waler pollution problems in major urban areas caused by various waler used by communities households, hotels,

hospitals and entertainment centers) in addition, the actions of the agricultural and

industrial sectors have resulted in water pollution, including mmeral exploitation and

hydropower generation ‘The degradation of water bodies and catchments due to

sedimentation, land erosion and drying out continues [3},14]

Poverty and Access to Clean Water and Sanitation throughout Lao PDR, there is

a high incidence of diarrhea and dysentery caused in part by inadequate water supply,

populations i urban and aptand arcas,

districts have less than haif the national average of daily water use, due to less access to water for either personal use or imigation purposes For this reason, various challenges exist in the field of water quality monitoring, modeling and other technical strengthening however, there is a need for a mote systematic approach Currently, some ministries and departments are responsible for water resources independently carry out water quality

mariagement, such as water quality monitoring and analysis I'he Water Resources and

Environment Administration (WREA) needs to play an active and leading role in water quality management in line with its mandate on water resources and environment Also, strongor watcr quility policias and strategies arc nected to dsal with the rapid

development of wator resonrass and possible impacls ơn walor qualily and ecosystems

‘The updaling of the National Water Resources Policy and Strategy and the

possible review of the Law on Water and Water Resources will provide the opportunity for this policy and strategy development Reviewing and setting coordinated water

quality monitoring standards and procedures need to be considered Furthermore,

capacity and systematic coordination procedures and mechani

ng amos ager responsible for overall and scctored water quality monitorinys and management nsed to be built [4]

Environmental measures used in solid waste management in Vientiane, including market and non-market instruments as well as public education and training programmers {moral suasion), Under pressure from rapid demographic growth, socio-economic

development and urbamzation, however, water quality is deteriorating, In urban areas, pollutants from roads, commercial and industrial areas, and private properties wash into drains and watercourses Litter, dust and ditt, oil and grease, particles of rubber

compounds ftom tires, particles of metal, glass and plastic ftom vehicles, and lead are common pollutants Residential propertics and open spaces contribute sediments and

nutrients [5] Urban drains also act

contaminated with faecal matter from latrines and coli-form septic tank effluent,

Wastewater monitoring was conducted in Vientiane in 2002 Samples were collected

fiom 15 monitoring stations Parameters were measured: pH, conductivity, alkalinity, BODs, COD and temperature, The monitoring results showed that the average of all

parameters were within acceptable limits, although certain samples exceeded standards

for Class A wastewatcr discharge, issued by the Goverment in 1994 [2]

Table 1 Wastewater Qualify in Vientiane Capital Jan-Dec 2000 (2]

Parameters | Unit ‘Range of Avg Results | Standard

1993, the institutional iamework has been established and followed up by a place of

logal framework for instances: Environmental law, land law, forestry law, water and

walor resources law, and others [3] Howaver, the growing number of industries has

incrcased (he risk af'pollution The larger mills and industries of concern in Tao PDR are pulp and paper, timber, food processing and garment manufacturing Most of these have

only limited wastewater treatment systems for reducing waste concentrations and loads in

the final effluents to waterways, Likewise, the inereasingly large number of smaller

industries also produces an increasing tisk of pollution There has been an increase in the output of in the industrial sector from 8 percent of GDP in 1999 to 11,3 percent in 2003 The total number of industries has grown ncarly four-fold fiom 1994 to 2003 (Table 2) Therefore, in accordance with the Millennium Development Goals, the government set targcts in oder to improve the local people’s access to safe drinking, water by the years

roanagement of natural resources, specifically water Moreover, the Environment

Protection Law (EPL), the Water and Water Resources Law and the zegulation on

wastewater discharge forbid any water pollution and propose that the personal sector be responsible for the environmental damage and the related social and economic effects

that result from their industrial activitics, specifically from wastewater and air cmissians

‘The Government's increasing focus on the importance of the private sector, in

(SMES), is commendable, Tr however, more strangly emphasize the importance of export oricntation and rove away

particular small and medium

from import substitution by various means of protection, » policy that most countries in the world, often after having experienced costly mistakes, have abandoned [6]

Kinally, in according by the presentment of the Minister of Industry and

Conmerce, in 2005 has regulation issued of the main condition on the industrial factories 17| are follows :

a) To prohibit discharging directly or indireetly into public waler thal may have adverse impacts on ecology of water body, health of peaple or use of water,

Đ To require getting approval on wastewater treatment system before starting construction of factories from Director of Industiy Department of the Ministry or Province as well as sulanil a treatment approach, wasle management system plan

©) ‘To rein stalling wastewater treatment system, volume measurement equipment, and other necessary facilities for monitoring, and sample analysis,

@ Tor

raporl the anatysis resulls to Director of Industry Department of the Ministry or

sire frequently monitoring moniloring and analysing the waslewater, and

Province,

e) To require recording the daily use of chemical substances and explaining the purpose of their use

1.1.3 Situation of pulp and paper mill in Vientiane

There are six pulp and paper mills in which five factory located in Vientiane

Capital City and one in Vientiane Province, Kor pulp and paper mills factories were

processed as to less than 200 tones of output per day, and small scale have to compared with in near countries KPS Paper mill is one factory in Vientiane Capital, this is factory using water fom stored in thưse underground buffer tanks and from supply water to the manufacture process The raw material processed is bamboo, which is reduced to chips bya cutter For delignification, the chips are immersed in a sequence of five tanks

containing caustic soda, an alkaline solution Sul fur is also added Aflor concentration, the chips are removed manually and placed in a grindor The pulp produced in the grinder station is mixed with recycled paper (which includes rejected and surplus paper) in

water tank 'the flow chart of the production line is shown in figure 2 After screening the mixture is transferred into the paper-making machines The finished paper is then

colored, cut and stamped before being packed for export The plant uses sodiwn

carbonate (NazCO,) or sodium hydroxide (NaOH) (ar cold sods) mixed with sul (S) amount, 1,688 lones‘year Lo deepen of the paper if nanufactures and exports In the

factory is gencral discharged effluent water amount 600 m’/day

Wastewater discharges from the factary has not installed any efiluent treatment system even though it is pre-determined in the factory's project document ‘Therefore, the

wastewater from the factory are two types of first black wastewater from the

delignification stage of the pulping process, and second white wastewater trom the paper making process, The black wastewater is discharged directly addicted to the local steam

and a scrics of ponds in the factory through two scparated pipclinc systems according [8]

is shown in table1.

Table 3.Ppllutants in the waslewafer in the faclory°s pands [8]

wastewater | wastewater | (industrial wastewater

discharged | discharged | Discharge regulation

——+] Delignification |.-—-_—» Black wastewater

Pulping Process Grinding |——>y Soliđwaste

igure 2 Source flawchart fra the productien line in KPS paper mill in Laos [8 1.2 The pulp and paper mill wastewater treatment technologies

1.2.1 Pulp and paper mill production

‘The charaeteristics of the wastewater generated from various processes of the pulp and paper industry depend upon the type of process, type of the wood materials,

process technology applied, management practices, internat recirculation of the effluent

for revovery, and (he ammount of waicr to be used inthe particular pra

‘That ths load of chlorinated phenols and acids in the wastewaters of hardwood kaaft mill was three to eight times lower than it was in the soft wood kraft mill The

pulping and paper making process is prominent compotind in the produce polfutants at various stages ‘Ihe wastewater pollution load from individual pulping and papermaking process, ‘There have

1, Mechanical forces in the presence of water (mechanical pulping), The process involves passing a block of wood, usually debarked, through a rotating grindstone where the fires are stipped of and suspended in water

2 Chemnical pulping which ulitiz

rocycted or disposed of by burring for hoat rzcovery,

3 A combination of the two (chemical thermo-mechanical pulping) ‘The wood is first partially softened by chemicals and the remainder of the pulping proceeds with

mechanical force According by G, Thompson, J Swain, M Kay, C.F, Forster | [0| in conventional mechanical pulping, the dissolved organic malarial from the wood is split

Lichweon the pulp passing onto the paper machine and that going to waste The

preponderance of the polhalants which go forward to the paper machine will subsoquenlly exist released in the paper machine wastewater, except where the process is operated in a closed loop system in difference, chemical pulping plants, with recovery systems in

place, find that most of the organic pollutants dissolved during pulping are retained in the recovered liquors which are generally incinerated The highest wastewater losses are

found in mills which operate chemi-mechanical process However, the wood pulping and production of the paper products gencrate a considerable amount of pollutants

characterized by biochemical oxygen demand (BOD), chemical oxygen demand (COD), suspended solids ($8), toxicity, and color when untreated or poorly treated cfflucnts are dis

depending upon the type of the pulping process This is made from cellulose fibers,

ged to receiving waler Pulp and paper mills generale varistias of pollutants

carbohydrates as sugar and Lignin, and is adhesive substance for the cellulose fibers ‘The current environmental limitations have cansed the decrease of the consumption of the natural resources for this industrial use So, in this industry the recycling of fibrous raw materials and/or alternative is the high water usage, between 20,000 and 60,000 gallons/t

of produets, results in large amounts of wastewater generation |11, |12| For the water utilization dependents on the technology and the product obtained were 3-8 m’/t Carton

af'preduel, 10-15 m/l Newspaper of product, 15-20 124 Paper tissue of product, and

Writing paper 10-20 m?/ of product [13] The wastewater from the papermaking and de~ inking process differs from the pulping process due to there being no breakdown of raw material, other than the discards of cleaning and screening Foremost sources of pollutant releases in pulp and paper mamnfacture in figure 3 Process description for pulp and paper mill factory 1t show below:

Thermo-mechanical pulping (TMP)

Figure 3 Prod 1.2.2 Sources of pollution

‘The pulp and paper industry possessions (wood, water) and fossil fuels, electricity anda significant contributor of pollution discharges to [he omissions (rom pulp and paper mills to air, water and land gives ø sơrions impael on environment quality thal ullimnately affects the healif of both human and ceosysiems, Howaver, the reeavery and rouse of water can increase the concentration of organic and inorganic species, whieh in turn can affect paper formation, increase bacterial loading or lead to corrosion and odours

According by D Pokhrel, T Viraraghavan [10| in boring the wood pulping and

production of the paper products cause a significant quantity of pollutants characterized

by biochemical oxygen demand (BOD), chemical axygen demand (COD), suspended solids (SS), toxicity, and color as untreated cfflucnts arc discharged to recciving water

The concentration of total wood cxtractives in the different fractions of the

influent and efflucnt from the activated shudge plant 88% of the wood extractives were removed in the activated sludge process In the determination of wood extractives the

normal procedure is Lo ternove targer particles by centrifiygation before extraction in

order to obtain reproducible results for dissolved and colloidal substances [11] However, integrated Kraft pulp and paper mill wastewater was characterized before (influent) and after (efiluent) the activated sudge process by micro-filtration and ultra-filtration into different size fiactions Wood extractives, lignin, suspended solids and certain trace

elements were determined in each fraction Forty four percent of the resin and fatty acids inthe influent (12.8 mg/L) occured in particles, 20% as colloids (0.45 mm 3kDa) and

In the effluent, resin and fally acids (1.45 mg/T) and sterals (0.26 mg/T),

small proportion in particles, b-sitosterol was present in particles in the effluent (88 _ 50

mg/L) [14]

‘The nsed effluents were obtained ftom the biggest pulp and paper mill in the mill produces about 140 tid of pulp from soft and hard woods A six-stage bleaching process chlorination, extraction, hypochlorite, chlorine dioxide, extraction, chlorine dioxide is usefidl to the cooked Kraft pulp, Combined leaching chlorination, extraction,

hypochlorite, chlorine dioxide, extraction, chlorine dioxide and the first three steps of the bleaching effluents constitute 30% and 60% of the total flow rate of pulp mill effluent,

respectively Spent ¢fucnis from th:

chlorinated compounds in the effluents has decreased, a discussion about the possible

nontal-chlorinc-frev (ECF) and total-chlorinc-fieu (TCF) Licached pulp mill cfflucnis has arisen, and chronic effects on aqualic organisms have

environmental 2ffe

slill been found{1 6} The charactcristies of the wastewaler gencraled from various

processes of the pulp and paper industry depend upon the type of process, type of the

wood materials, process technology applied, management practices, internal recirculation

of the effluent for recovery, and the amount of water to be used in the particular process and others are generated in the pulp and paper making process show in figure 3

Pollution from the pulp and paper industry can be minimized by various internal process

changes and management measures such as the Best Available Technology (BAT)

Therefore, there were necessary to bring in some kind of treatment of the

wastewater For the treatment method and increased knowledge about the underlying

there is a complete preference af different mechanical physical, chemical and

Liclogical methods thal can be combined in different ways in order to achieve cost

efficient wastewater treatment ‘he wastewater composition and the amounts of different

substances in wastewater, and one fundamental dissection are between dissolved

substances and particular matter For the common methods are analyses of total solids (T8), total suspended solids (FSS), and volatile suspended solids (VSS), ane more large division is between inorganic and organic compounds The determination of ammonium - nitrogen, other phosphate and nitrate-nitrogen are examples of some of these specific

methods Organic compounds arc applying measured by humping methods, such as total organic carbon (TOC) and dissolved organic carbon (DOC) A lal of methed have heen developed in order to determine how much pollutants a wastewater is made are chemical oxygen demand (COD) and biological oxygen demand (BOD) Tlowever, have many different methods represent the most common ones in the wastewater treatment field The mainly important method for characterizing the wastewater is COD Beside that methods comparable to TOC could also be used but then they have to be correlated to COD The amount of degradable matter in the wastewater can be determined with BOD but this

method while only gives au estưnate, VSS is the best measure of the amount of microbial biomass in the wastewater treatment plant TSS could also be used but inorganic :nafter

preparation

Figure 4 Pollutants from various sources of pulping and pupermaking [11]

1.3 Some methods commonly using to treat with the wastewater

1.3.1 Physicochemical treatment

Physicochemical treatment processes include removal of suspended solids,

colloidal particles, floating matters, colors, and toxic compounds by sedimentation,

flotation, screening, adsorption, coagulation, oxidation, ozonation, electrolysis, reverse osmosis, ultvafiltration, and nano-filtration technologies

1.3.1.1, Coagulation and preci

mill wastewater treatment and not commonly adopted in the primary treatment It carried

cut a comparative sludy of harscradish poroxide (chitosan) and other cougulants such as (Al{(S0,);), hoxamalhyienc diamine cpichtarohydrin polycondansats (HE),

polyclhyloncinine (PED, ta remove adsorbable organic halides (AOX), total organic

carbon (LOC), and color [9] Coagulation is mainly induced mainly reduced by inorganic metal salts, e.g aluminum and ferric sulphates and chloride Polyelectrolytes of various structures, e.g polyacrylamides, chitosan, polysaccharides, polyvinyl and many more are usually used as coagulant aids to enhance the formation of larger floc in order to improve the rate of'sedimentation, According to AL, Ahmad, 8.8, Wong, T.T Teng, A Zuhairi [17] pulp and paper mill wastewater was treated by using the alum and polyaluminum chloride (PACI) alone and in coupled with cationie polyacrylamide (C-PAM) and anionic polyacrylamide (A-PAM) The reduction efficiency of tmbidity and chemical oxygen demand (COD), removal efficiency of Lolal suspended solids (TSS), sludge volume index (SV1) and seilling time are the main evaluating parameters In coagulation-foceulation process using single coagulant, coagulant dosage and pH play an important role in

determining the coagulation efficiency At ths optimum alum dosage of 1000 mg/L and

optimm pH of 6.0, turbidity reduction is found to be 99.8%, I'SS removal is 99.4% and

COD reduction is 91% The optimum dosage and pH for PACI are 500 mg/L and 6.0, respectively, at which it gives 99.9% reduction of twbidity, 99.5% of TSS removal and 91.3% of COD reduction, A combination of inorganic coagulant and flocouilant or

polymer is applied in which ahun and PACI are used coupled with the CPAM

(Organopot $415) and A-PAM (Chernloc 430A) Overall, alm conpled with Organopol

3415 is ths best system among all systems studied It gives 99.7% reduction of turbidity,

99.5% removal of TSS and 95.6% reduction of COD, and at the same time with low SVI

(38 mL‘g) and low settling time

“rhe combined method (coagulation followed by photocatalysis) has been

developed by Angela Claudia Rodrigues et al [18] to improve the efliciency of the

treatment of wastewater from pulp and paper mill factories First, the effluent was

submitted to the coagulation flocculation treatment by applying FeCl as the coagulating agent and chitosan as an awdliary, In sequence, the aqueous soluble phase obtained from the fit tre s submitted ln a UWiTIOW HO 8

d coagulation experimental conditions were chosen: pH 6.0, 80 mg 17 of

cm using mercury lamps The

optir

FeCl; 6H20, and 50 mg 17! of chitosan The optimized photoealalysis conditions were:

pli 3.0in 0.50 ¢ L of Ti0- and 10 mmol L™ of 11-0., COD values for the in natura

sample was 1303 mg L | and after the optimized conditions of coagulation without

chitosan and in chitosan prssenoe were 545 and 516 ing L", respectively, Effluent

after coagulation Additionally it was observed an absorbance reduction of 90% at the

wavelength of 500 nm and of 70-80% in regions corresponding to aliphatic and aromatic

Ä-organie, rrlrale, nitrite, phoaphøtz,

aroups (254, 280, and 310 nm) The use of chitosan for quantitative purposes was not so efficient, however, it improves sedimentation and compaction COD results of

photolyzed samples by UW/H202 were 344 mg L"!, UV/TiO2 326 mg Lt, and

UV/TI02/H202 246 mg L™., The reduction in absorbance intensity was approximately 98% for aliphatic and aromatic chromophores, and 100% for chromophores absorbing at

500 nm with color disappearance The wastewater treatment canied out in association at

optimized experimental conditions provided goad results,

1.3.1.2 Adsorption

Adsorption is the incorporation of a substance in one state into another of a

different state (e.g, liquids being absorbed by a solid or gases being absorbed by a liquid)

Is the physical adherence or bonding of ions and molecules onto the surface of another phase (e.g, reagents adsorbed to solid catalyst surface) Amongst various tertiary

treatinent processes, adsorphon has been found to be attractive for the removal of most erganie compounds in wastewaters, especially al lower comacntrations Activated carbon

Jas been the mnost eormmonty used adsorbent Howaver, high cost of activation, and

regeneration and the disposal of the concentrate ftom the cleaning cycles pose problems

in the use of activated carbon Hence, the search of new low cost adsorbents has attracted

a number of investigators Several low cost adsorbents like wood, coir pith, coal fly ash, bagasse fly ash (3FA) and coal-fired boiler bottom ash have been used for the treatment ofa wide variety of wastewaters, A high removal of color by activated charcoal, fuller’s earth, and coal ash have reported ‘the removat of color, COD, DOC, and AOX from

bleached wastewater by the adsorption process, using activated coke as an adsorbent,

have concluded by activated carbon and ion exchange The lignin removal efficiency to rộnco color and chloride to levels aecoptibls for rense have investigated [17-19]

Accordimg by [20] has reposted the adsorption process was performed at ambicnt temperature in an orbital shaker cum incubator During the test, 50 ml of wastewater was

added in five conical Masks In ecach flask, different amounts activated carbon was

vi

added, Afier optimizing the adsorbent dose, pH of the wastewater was adjusted by adding

TMNHOH or £.8 M H280, The flasks wore then shaked al 120 rptn for 1h duration The

treated samplocs wars Gilferad by passing throngh a filler paper and the fillrale was

analyzed for different parameter(such as pH, COD and TOC)

1.3.1.3 Chemical oxidation

Chemical oxidation were most commonly employed to date include peroxide,

‘ozone, and permanganate, Advanced oxidation processes (AOPs) such as ultrasonic

irradiation in combination vvith Fenten-like oxidation(Fe' “H:O;) ơr photo-Fenton

degradation (Fe* /H,O.UV) were also separately tested, Effects of operating parameters such as pH and oxidant’s dosc on the removal of organic compounds were investigated in tems of COD removal [18] Chemical oxidation of Krait pulp bleaching wastewater was investigated by many researchers [17] showed that the use of horseradish peroxide to

decotorize Kraft effluent by 50% within hres hours of reaction time The degradation of phenotic and polyphenolic compounds presaut in the bleaching effluent was studied using

advanced oxidation systems such as photocatalysis with Oo/ZnO/LV, O+ (UV, Os

and O,/UV ‘The authors concluded that OyZnO/UY and Os/IiOz/U V were the best

systems to oxidize the effluent in a short period of time ‘Ihhe combination of Fenton and photo-fenton reactions proved to be highty effective for the treatment of bleaching Kratt mill effluent, Ozonation is a process for infusing water with ozone, this is commonly

done to kill bacteria and other organisms, but also for color, taste and odor control | 19

All ozonation experitnents were carricd out af room Letmperature (23-30°C) in a semni-

continous glass reactor (230 mi.) with the initial ozone concentration of 30 mg/l during

60 min The ozone/oxygen mixture, with the gas flow of 0.5 mL/min, by the porous

ceramic in the inferior part of the reactor was distributed The ozonation of the diluted and filtered samples after precipitation was carried out at the initial pII 1, 3, 8 and 12

[21]

Ð Pokhrel, 1, Viraraghavan [9] have give overall reviews of application of the ozonation processes for the removal of COD, TOC, and toxicity from pulp mill effluent and increased biodegradability of the effluent were achieved after treatment with ozone Their summarized that a 90% removal of ethylenediaminetetraacetic acid (EDTA) and a 65% removal of COD by ovauc Irealment of the pulp mill effluent, after 60 min of exo nation Lotal organic carbon, total phenols teduecd to 12% and 70% respectively, and

cffucnt colors to 35% of bleached pulp mill effluent Several authors reported on toxic compounds, COD, and color removal by ozone treatment Some authors indicated that a high dosage of ozone (100-300 me/ dm*) was required to remove S0% of lippphilic wood

xi

extractives, The ozone doses of 0.2 mgO,finitial mg COD can elimmate over 90% resin acid High removals of TOC, COD, AOX, and color from bleached kraft anill cffluctt (RKME1) using hotorngoncous photocalatysis and oxonc troalmenl ean be achieved by

diluting Kraft pulp mill effluent in distilled water Sarnple pIT we

adjusted to 18 fferent levels (4, 7 and 16) 100 mÏ, samples were filled into cellulose menubrane sacks, The

sacks were kept dipped in 1000 mb distilled water baths for 24hrs and removed Samples for ozonation were taken from the water bath, which contained efiluent molecules passed through the membrane [22] However, membrane filtration is defined under the rule as a pressure or vacuum-driven separation process in which particulate matter larger than 1 năm is rejected by an engineered barrier, primaily through a size exclusion mechanism, and which has a measurable removal efficiency of a target organism that can be verified

st The membrane surfaces were

through the application ofa dirccl integrity

characterized inter of the mean rough

and the mean difference in height between the highest and the five lowest point (R.)

Membrane characterization are Atomic force microscopy (AFM) imaging allowed

comparison of surface of clean and fouled membrane and Scanning electron

85 (Ra), the rool mean squarer roughness (Rane)

microscopy(SEM) measurements were used to provide detailed structural

information of membranes including pores inside the membrane [23]

According by E.Dialynas, E.Diamadopoulos [24] has reported high removals were also observed for vaitous heary metals, The removal values were above 90% for

Co, Ni, Mn, and Sr Ultrafiltration membranes can achieve similar results for heavy

inciais whon thuy are so in a membrane bicreactor (MBR) systom arrangerent,

efflucnt pH showed srnall variation and il ranged between 8.0 and 8.1, and the

ullaGiltration owing tovast improvement in their manufacturing tockmologies,

posseess very high permeability Phis has allowed many ultrafiltration applications

operate under much lower trasmembrane pressure, as low as 7 KPa (1.01 psi) according

xvil

by [25] has reported the treatment of wastewater of paper mill with integrated membrane

process, the conventional realment can nat mel the requirements of waler qualily Cor the

papor making process The integrated membrane process in pilot scale which consists of the membrana bioreactor (MBR), the continuous tombrane filtration (CMF) and the

reverse osmosis (20) is used to treat the wastewater of this paper mill ‘The discharged

water from the first sedimentation tank was treated with the anoxie/aerobic/MIR

menibrane system fo eliminate NH; N and dissolved organic compound

1.3.3 Biological treatment

1.3.3.1, Aerobic treatment

Actobic treatment usc of fice or dissolved oxygen by microorganisms (acrobes)

in the degradation of organic wastcs Since oxygen is available to working acrobes as an electron acceptor, the bicdcgradation proccss can be significantly acccleratcd, leading to increased throughput capacity of a treatment, system There are numerous liological

treatruenl systems available, the most common being the activated sludge process The distribution of organic loading rate values is similar ‘The full range of operational

parameters of a typical activated sludge plant treating effluent from pulp and paper mills

‘The performances achieved by activated shudge plants being used for the treatment of paper mill wastewaters That very high removal efficiency can be obtained both far BOD and COD removal Aerobic cultures were obiained from the aeration tanks of the

activated sludge units of the Ankara Municipal Wastewater Treatment Plant, Turkey,

with a sludge age and organic loading of 2.8 days and 165,000 kg BOD,/day,

respectively [9], [26]

Several authors [17] have reported a high reduction of BOD and soluble COD by

a two-stage activated sludge process They suggested upgrading the activated sludge

plant by the addition of Floobeds (floating biological bed) in series that increased COD

and BOD removal from 51% to 90% and 70% to 93%, respectively ‘he microorganisms

such as Pseudomonas putida, Citrobacter sp., and Enterobacter sp, were found efficiency for the removal of color, BOD, COD, phenolics, and sulfide in the activated sludge

process, The removal of chlorinated phenols, 1,1-dichlorodimethyl sulfone (DDS), and chlorinated acetic acids in an oxygen activated shudge effluent treatment plant were also

Teported The removal of 90% BOD,, 70% COD, 40-60% AOX, and 60-95% chlorinated

phonols ernoval in the activated sludge proc

(1994) stated that 70% roroval of the AOX from the acraled lagoon was altribuled fo a short residence time section of the treatment system where the chlorinated stage effluents were mixed with general mill wastewaters ‘Ihe effect of simple mixing was reported to

was achieved Stulhridge and Mefarlans

xữx

be responsible for 15 46% removal, Other researcher reported removal of BOD, ranging bebweon 50% and 75% and chlorinated phenolics 10-50% by an acrated lagoon High removals of organic pollutants of Krafl mill wastewater by sequencing batch reactor

(SBR) treater! have ropood by other searchers The removel of methanol COD sols

are 100% and 90% respectively by SBR Substantial removal of COD, TOC, BOD, lignin

and resin acids of 'MP wastewater using high rate compact reactors (LICRs) at a

retention time of 1.5 h had been reported, Removal of COD by a moving bed bifilm

reactor (MBBR) had been demonstrated and concluded that suspended carrier biotilm reactor (SCBR) was highly efficient in removing chronic toxicity from the effluent The usc of a biofiltcr can achiove 76%, 62%, 81%, and 48% removal of BOD, COD, $8, and AOX, respectively Typical cffioienics of acrobic systems arc presented ina table 4

Table 4 Typical efficiencies of aerobic systems [9]

System ‘Aeration Organic loading (Ib Efficiency (%)

time (day) = BOD/1000 ff)

wastes It has many potential advantages in comparison to aerobic treatment, such as

lower sludge production, lower chemical consumption, smaller land requirements due to smaller reactors and energy production in the form of methane, The use of a two-stage anaerobic - aerobic approach to remove COD and sulphate trom the wastewaters

gonoralcd al an integrated newsprint mill COD and sulphur removals wore 66 por

and 73 perosnl, respectively In goncral, anaerobic digastion is carticd oul at mesophilic toruperaturas, 35 Io 37°C However, the use of the thermophilic temperature range is

value considering as it will give faster reaction rates and a higher gas production rate [9]