Studying the capability of greywater treatment on site by using laterite material

1.1 The aim of research Determination of greywater characteristics from some buildings in Hanoi city; Explaination of the principle of removing the main pollutants out of greywater by u

MINISTRY OF EDUCATION

AND TRAINING

MINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT

WATER RESOURCES UNIVERSITY

KHUONG THI HAI YEN

STUDYING THE CAPABILITY OF GREYWATER

TREATMENT ON SITE

BY USING LATERITE MATERIAL

Major: Water resources engineering Code: 62580212

DOCTORAL THESIS ABSTRACT

HANOI, 2016

The research is completed in Water Resources University, Hanoi, Vietnam

Advisor 1: Assoc Prof., Dr PHAM Thi Minh Thu

Advisor 2: Assoc Prof., Dr NGUYEN Thi Kim Cuc

Reviewer 1: Dr TRINH Xuan Lai, Vietnam Water Suply and Sewerage Association Reviewer 2: Assoc Prof., Dr NGUYEN Ngoc Dung, Ministry of Construction Reviewer 3: Prof., Dr TRAN Huu Uyen, Expert of Water Treatment

The doctoral thesis has been presented at Water Resources University,

INTRODUCTION

1 Urgency of research:

Greywater accounts for 69%1 of domestic wastewater flow and contaminant concentrations lower than the blackwater but most of the pollution parameters are not meet up the Regulation to discharge directly into the environment Wastewater treatment technology such as SBR, A2O only effective in treatment

of organic matter but not effective in treatment of nitrogen to reach the require level; and often apply to big wastewater treatment plants Need to research a suitable processing solution with the scale and characteristics of greywater as the criteria for: simple operation, high nitrogen removal efficiency, area of land occupied is less and towards sustainable technologies

Laterite is local materials, available in many areas in Vietnam country Laterite

is form structure, contains many kinds of minerals such as clay (kaolinite, bentonite), the hydroxides of iron, the hydroxides aluminum, zeolite, brucite, gibbsite, goethite2 are substances that the polarity inside the water, with the ability to exchange ions, in the crystal structure, manies void and large specific surface area Therefore the laterite is easy to join the adsorption, ion exchange, electrostatically with some pollution matter and having the potential of wastewater treatment field However, these ability is reduced with time, together with the clog process because the developed of microbial membranes This problem can improve with using laterite according multilayer soil layering engineering3

Thesis "Studying the capability of greywater treatment on site by using laterite material" was conducted to determine the ability to treat the greywater of laterite with multilayer layering engineering The success of the studing is opened up a new direction in the use of local materials, environmentally friendly to treat greywater on-site; contribute to reduce pressure on the

1 Barnes, D và cộng sự, Water and Wastewater Engineering Systems, Pitman Books Ltd., ed London, 1981

2 Nyle C.Brandy, The nature and the Properties of soils, 2nd ed.: ISBN: 9780130167637, 2001.

3

T.Masunaga et al, "Characteristics of wastewater treatment using a Multi Soil Layering system in relation to wastewater

contamination level and hydrolic loading rates," Soil Science and Plant Nutrition, pp 123-125, 2007.

wastewater treatment plants, the length of urban pipelines and environmental pollution The treated of greywater can be used for irrigation, control the distribution domestic buildings and saving water resources for the future

1.1 The aim of research

Determination of greywater characteristics from some buildings in Hanoi city; Explaination of the principle of removing the main pollutants out of greywater

by using laterite with multi soil layering engineering; Determination of decomposition rate coefficients of BOD5, COD and NH4

+

-N The number of laterite layer is calculated based on these coefficients; Successful greywater treatment from building by using laterite with Multi Soil Layering engineering and the treated effluent meet up the National Regulations (QCVN 14:2008/BTNMT; QCVN 08-MT:2015/BTNMT)

1.2 Object and scope of research

1.5 The scientific and practical significances

1.5.1 Scientific significances

- Determination of decomposition rate coefficients of BOD5, NH4

+

-N and COD The number of laterite layer is calculated based on these coefficients

- Determination of efficiency, explaination of the principle of removing the main pollutants out of greywater by using laterite with multi soil layering engineering;

Applying for greywater treatment from buildings in Hanoi city The quality of effluent meet up the National Regulation QCVN 14:2008/BTNMT; QCVN 08:2008/BTNMT

1.6 The structure of the thesis

The structure of the thesis beyond the preamble; conclusions and recommendations; lists of articles were published; reference section; annexes; Thesis is presented in threes chapters, including:

Chapter 1 Overview of the research problems

Chapter 2 Basic of scientific, material and studying method for greywater

treatment by using laterite with Multi Soil Layering Engineering

Chapter 3 The research results of greywater treatment on-site by using laterite

with Multil Soil Layering engineering

CHAPTER 1 : OVERVIEW OF THE RESEARCH PROBLEMS

Greywater is part of the waste water without treatment and collected from showers, lavabol, tub, kitchen sink… (except toilet and urine sink) and accounted for 69% of domestic wastewater The pollution concentrations of organics and nutiens such as BOD5, COD, N, P are lower than the concentration of black wastewater The pollution concentrations in greywater depends on habit and level of living, traditional, economic conditions, management, methods of greywater collection and source of drainage etc each area

Greywater is treated by chemical – physical, biological, mechanical method These are many researchs of greywater in the world, the greywater is treated to seek of resources water saving in future or reducing of environmental pollution Some case studies such as M Halalsheh, 2008 (Jordan); Peter L.M Veneman and Bonnie Stewart, 2002 (USA); Elmitwalli et al, 2000 (Netherlands) In Vietnam, Stefania Paris and Celine Schlapp, 2010; N.V.Anh

et al, 2012; K.T.H Yen et al, 2014 studies greywater, the results show that most

of the contaminants concentrations exceed the allowable value specified in the QCVN14: 2008/BTNMT Therefore, the greywater are required to treat before being discharged into the environment

1.2 Laterite and Application for wastewater treatment

These the mineralogy of laterite are clay (kaolinite, bentonite), the hydroxides

of iron, alumina, zeolite, diatomite, and has been characterized by the topology

of the form -O-H H-O-H-O loose Group OH- ions easily combined with oppositely in retail gas oxygen atoms in this link may be involved in the process of cellular respiration of the microorganism; the basic structural unit consisting of a tetrahedron made of Si and O, the octahedral blocks from OH- and metal cations Al3+, Fe3+ Al3+ ions, Fe3+ is likely linked to the opposite ion

is the glue sound in wastewater4

These are a lot of researches which using laterite as absortion material for wastewater treatment Such as R B Wood and C F Mc Atamne, 1996 (USA); Avinash M et al, (India); Mitali Sarkar et al, 2006 (India); Saynor MJ & Harford, 2010 (USA); Yu Xiaohong et al, 2009 (China); Felix Udoeyo et al,

2010 (USA); Liang Zhang et al, 2011 (China); I.M.M Ranhman et al, 2008 (Japan) In Vietnam, Nguyen Thi Hang Nga, 2014; Tran Hong Con, 2010; Dang Duc Truyen, 2011 research on laterite and heat denaturation to made filter material for water treatment The result show that laterite can treat the fluoride,

4 Đỗ Thị Vân Thanh, "Laterit - đá ong hóa và sự thoái hóa đất của một số tỉnh vùng đồi Trung du miền Bắc Việt Nam," 1995

heavy metal with high performance; the organics concentration is reduced but creating of residues, it’s the cause to make flog inside the multi soil layering system Most of researches processed inside the laboratories with assuming pollution matter then different distance when application in real

1.3 Multi Soil Layering

Multi Soil Layering is using multi- layers of material with original from soil, arranged in a certain sequence to treat the contaminants inside wastewater T.Matsunaga research and develop the Multi Soil Layering from the 1990s in Japan as a wastewater treatment solution with low cost (Fig 1.12)

Fig 1.12: Structural diagram of multi soil layering

In this thesis used the results of some laboratory researches, such as: With the soil unit are thick then effect to treat nitrogen but making the clog quickly; With soil unit are thin then effect to treat organics but not effective for nitrogen; With the soil units are thickness and narrow then the perfomance of contaminants are average but can work well with high hydraulic loading, less clog and the hydraulic retention time inside the multi soil layering is inversely related to the hydraulic loading5 The pollution levels of contaminants inside wastewater input less effection to treatment performance of suspended solid, organics and nitrogen but more effective to phosphorus; Hydraulic loading is is inversely related to performance of phosphorous; The arrangement of the

5 Sato K., Masunaga T., Inada K., Tanaka T., Arai Y., Unno S and Wakatsuki T., "The development of high speed treatment of polluted river water by the multi-soil-layering method, Examination of various materials

and structure," Jpn J Soil Sci Plant Nutr., vol 200, 2005

Influent

Effluent

Soil units: These units are made from soils, complete the decomposition process of organics, nutrients base on the activities of exotic, aerobic and anerobic bateria

Lining: Using of material such as activated carbon, zeolite, gravel for adsorption and decomposition the contaminants base on the adsorption capactity of material and activities of materia

material structure is meaningful and high treatment performance when hydraulic loading is less than or equal 2.000 L/m2.day When the wastewater loading is beyond 2.000 L/m2.day then the structure arrangement of material is not effective much to the treatment performance6 Until now, there is not any research of application the multi soil layering engineering in Vietnam

CHAPTER 2 : BASIC OF SCIENTIFIC, MATERIAL AND STUDYING METHOD FOR GREYWATER TREAMENT BY USING LATERITE WITH MULTI SOIL LAYERING ENGINEERING

2.1 Basic of scientific for greywater treatment by using laterite with multi soil layering engineering

- The adsorption reaction occurs with the adsorption kinetic model The ability

of the contaminants adsorption of laterite was evaluated using the Langmuir equation (2-1):

(2-1)

- Organics, nutrients inside the greywater are removed through the action of available microorganisms Model of decomposition Monod is used to determine the biodegradation coefficients and is written as follows7:

Laboratory models made of stailess steel, cube with dimension Length x Wide

x High = 15x50x(33-76) cm; inside made of 3,4,5,6,7 laterite layers and the laterite unit is stagger between up and next down layers, like brick wall (MSL3,

6

Xin CHEN et al, "Effect of structural difference on wastewater treatment efficiency in Multil Soil Layering

systems: Relationship between soil mixture," Soil Science and Plant Nutrition, vol 53, p 206–214, 2007.

7 Lawrence A.W and McCarty P.L., "A unified basis for biologycal treatment design and operation," Journal

of the Sanitary Engineering Division , American Society of Chemical Engineers, vol 96, p 757, 1970.

MSL4, MSL5, MSL6, MSL7); row distance is 3 cm, column distance is 2,5 cm and insertion by heat denaturation laterite with diamter 1-3 mm; the gravel is bottom of laboratory madel with diameter 4-6 cm, thickness of this support gravel is 10 cm (Fig 2.14)

Fig 2.14: Lab model of Multi Soil Layering After removing the rubbishs, the greywater is distributed with the 2.000 littre/m2.day hydraulic loading to every laboratory models The samples are took at influent and efflent point of every model

MSL7 MSL6

MSL5 MSL4

MSL3

some apartments of the B5-Yen Thuong MSL6-PL made of force glass, 1.2 thickness and placed in a steel frame inside with 6 natural laterite layers arranged in staggered layers; Grades 3 cm apart and rows spaced 2.5 cm and inserted laterite heat denaturation granular 1-3mm diameter; bottom gravel layer 4-6 cm thick support diameter 10 cm Gray waste water collected from the B5-Yen Often garbage removal and lead to a 200-liter tank, then pumped into the tissue quantification Fig with hydraulic load of 2,000 liters / m2.ngay Below the water sampling valve for later processing The system is operated continuously for 24 hours/day Samples were taken at the beginning of the in and out of scale Fig 10 days (Fig 2.18)

Notice: 1 Influent of greywater; 2 Storage tank 200littres; 3 Pump; 4 Flow meter; 5 Weir of distribution; 6 Distribution system; 7 Laterite; 8 Heat laterite; 9 Gravels; 10 Collection of treated; 11 Storage; 12 Pipeline; 13 Over flow; 14 Dosing equipment

2 1

Fig 2.18: Diagram of pilot model of MSL6-PL

CHAPTER 3 : THE RESEARCH RESULTS OF GREYWATER

TREATMENT ON-SITE BY USING LATERITE WITH MULTI SOIL LAYERING ENGINEERING

3.1 Characteristics of greywater from buildings in Hanoi city

The results of laboratory analysis: the average concentration of contaminants inside the greywater samples which collection from some buildings (CT5B –

Me Tri, 11 floor condominiums of Duc Giang, building of B5 Yen Thuong) at Table 3.1 showed that the concentration of organics, nitrogen, suspended solids total exceeded many time value which certificated in Regulation

QCVN14:2008/BTNMT (B)- National technical regulation on domestic

wastewater Therefore, the greywater forced to treat before discharge into the environment

Table 3.1: Characteristics of greywater from some building in Hanoi city

3.2 The research results on laboratory model of Multi Soil Layering

After 1st day, the total water column is reduced about 30cm, equivelent 30% total of influent flow, because water come inside the material From 2nd da, the total water column is reduce less about 1,5% and mostly have no change from 3st day, it show that the material is saturation and the flow of effluent is stable Thus the reduction just occurred mainly in the first 2-3 days of water soaked into the material and forming saturated state The reduction of flow is proportional to the number of laterite layers in the system

soil layering

The performance of BOD5 reached from 77,22% to 90,60%, the concentration

of effluent reduced below 20 mg/L for greywater; The performance of BOD5

reached from 70,50% to 80,33%, the concentration of effluent reduced below 10mg/L for dilute greywater (Fig 3.3, Fig 3.4)

8 Harremoes Henze and La Cour Jansen Arvin , "Wastewater Treatment: Biological Process," 1996.

Fig 3.3: Concentration of BOD5 before and after treatment of greywater

Fig 3.4: Concentration of BOD5 before and after treatment of dilute greywater The performance of BOD5 BOD5 proportional to the number of laterite layers and BOD5 concentrations in influent The concentrations of BOD5 droped fastest through 3 - 4 upper laterite layer

After 6-7 laterite layers then COD concentration of effluent is stable For greywater, the performance of COD reached 45,72%- 71,61%, COD concentration of effluent reduced below 30mg/L (Fig 3.5, Fingure 3.6)

Fig 3.5: Concentration of COD before and after treatment of greywater

Nước thải đầu vào Nước sau MSL4 Nước sau MSL3 Nước sau MSL5 NTPL

Nước sau MSL6 Nước sau MSL7