Wastewater Treatment In Public Market Using External Membrane Bioreactor

WASTEWATER TREATMENT IN PUBLIC MARKET USING EXTERNAL MEMBRANE BIOREACTOR

A Seminar Paper

In Partial Fulfilment of the Requirements for the Course Industrial Waste Management and Control

By Jan Cecilia A. Bautista

May 2017

LETTER OF TRANSMITTAL May 2017 ENGR. CEASAR P. LLAPITAN Instructor Chemical Engineering Department Cagayan State University-Carig Campus

Dear Engr. Llapitan: I am herewith submitting my report entitled “Wastewater Treatment in Public Market using External Membrane Bioreactor” in partial fulfilment of the requirement for the Course Industrial Waste Management and Control. The main objective of this report is to design a wastewatertreatmentfacilityfor public markets. This study shows the membranebioreactorparameters and calculations needed for the design. I hope that this will merit your approval

Very Truly Yours, Jan Cecilia A. Bautista

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Table of Contents Title Page Letter of Transmittal ................................................................................................................................... i

Table of Contents .......................................................................................................................... ii Chapter I: INTRODUCTION .............................................................................................................. 1 A. Aim and Objectives .............................................................................................................1 B. Sources of Wastewater .........................................................................................................2 C. Public market .......................................................................................................................2 D. Wastewater Treatment Plant ................................................................................................3 E. Legal Basis of Wastewater Treatment .................................................................................4 F. Tuguegarao Public Market ...................................................................................................5

Chapter II: PROCESS DESCRIPTION AND SELECTION....................................................6 A. Market Wastewater ..............................................................................................................6 B. Treatment of Market Wastes ................................................................................................7 C. Membrane Filtration ...........................................................................................................7 D. Membrane Bioreactor ................................................................................................................... 9 1. Configurations of Membrane Bioreactor .......................................................................9 Chapter III DESIGN ............................................................................................................................. 12 A. Wastewater Characteristics ........................................................................................................ 12 1.

Raw Wastewater Characteristics ..................................................................................1

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B. Process Flow and Information ...........................................................................................13 C. Component of the Designed MBR Facility .......................................................................14 1.

Anoxic Tank..............................................................................................................15

2. Activated Sludge Tank ...............................................................................................15 D. Operational Parameters ......................................................................................................16 E. Design Calculations ...........................................................................................................17 1. Screening ....................................................................................................................17 2. Equalization Tank.......................................................................................................18 3. Activated Sludge Tank ...............................................................................................22 4. Oxygen Requirements ................................................................................................24 5. Sludge Wasting...........................................................................................................25 6. Membrane Design ......................................................................................................26 Chapter IV CONCLUSION ........................................................................................................27 REFERENCES ....................................................................................................................................... 28

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CHAPTER1

INTRODUCTION

Nature has an amazing ability to cope with small amounts of water wastes and pollution, but it would be overwhelmed if we treat the billions of gallons of wastewater and sewage produced every day before releasing it back to the environment. (T.Subramani, Porkodi, & Jayalakshmi, 2014)

We consider wastewater treatment as a water use because it is so interconnected with the other uses of water. Much of the water used by homes, industries, and businesses must be treated before it is released back to the environment. (Rakesh Kumar, 2006)

Wastewater is used water. It includes substances such as human waste, food scraps, oils, soaps and chemicals. In homes, this includes water from sinks, showers, bathtubs, toilets, washing machines and dishwashers. Businesses and industries also contribute their share of used water that must be cleaned.

Wastewater also includes storm runoff. Although some people assume that the rain that runs down the street during a storm is fairly clean, it isn't. Harmful substances that wash off roads, parking lots, and rooftops can harm our rivers and lakes.

A. Aim and Objectives Treating wastewater has the aim to produce an effluent that will do as little harm as possible. The objectives of the study is to design a wastewater treatment facility that discharges an effluent complying with the standards stated in DENR Administrative Order (DAO) No. 35.

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And to reuse the highly treated wastewater as water supply for the public market for human recreation, i.e. washing meat, fish, fruits, and vegetables; flushing, and bathing.

B. Sources of wastewater

a.) Domestic Sewage

This includes all wastewater generated by home dwellings, public restrooms, hotels, restaurants, motels, resorts, schools, places of worship, sports stadiums, hospitals and other health centers, apartments and the like. They all produce high volumes of wastewater.

b.) Non-Sewage

These include water from floods (stormwater), runoff (rain water running through cracks in the ground and into gutters), water from swimming pools, water from car garages and cleaning centers. They also include laundromats, beauty salons, commercial kitchens, energy generation plants and so on.

Wastewater is also generated from agricultural facilities. Water used for cleaning in animal farms, washing harvested produce and cleaning farm equipment.

C. Public market

Public markets in the Philippines generate high in strength wastewater and in effect, may pollute the nearby bodies of water destroying aquatic life and as well as the whole water body. Wastewater from these establishments is generated from different sources and activities. Sources of these are meat, fish, poultry, fruits and vegetables that are sold. Food stalls and public restrooms are also present contributing to the wastewater. These sources are able to

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generate wastewater containing high levels of organic material, suspended solids, fats, oils, and grease that contains about two to three times the organic matter and solids typically found in domestic wastewater.

The construction of a MBR treatment facility is very important and can be very useful to the public market. The facility can contribute to the sustainable development and can treat wastewater to the extent that it can be reused again as a water supply for commercial and domestic purposes for the market area. The MBR facility can also reduce the level of organic material, suspended solids and other particles that comprises the wastewater up to the point that the effluent will be meeting the quality of effluent standards (Lazaro, Miura, & Perez, 2014).

D. Wastewater Treatment Plant Wastewater treatment is the process of removing contaminants from wastewater, primarily from household sewage. There are numerous processes that can be used to clean up wastewaters depending on the type and extent of contamination. Wastewater can be treated in wastewater treatment plants which include physical, chemical and biological treatment processes to remove these contaminants and produce environmentally safe treated wastewater (or treated effluent). One type of aerobic treatment system is the activated sludge process, based on the maintenance and recirculation of a complex biomass composed of micro-organisms to be able to absorb the organic matter carried in the wastewater. Anaerobic wastewater treatment processes (UASB, EGSB) are also widely applied in the treatment of industrial wastewaters and biological sludge. Some wastewater may be highly treated and reused as reclaimed water. Wastewater collection and treatment is typically subject to local, state and federal regulations and standards. 3

Treating wastewater has the aim to produce an effluent that will do as little harm as possible when discharged to the surrounding environment, thereby preventing pollution compared to releasing untreated wastewater into the environment. E. Legal Basis of Wastewater Treatment In the Philippines, Republic Act 9275, otherwise known as the Philippine Clean Water Act of 2004, is the governing law on wastewater management. It states that it is the country's policy to protect, preserve and revive the quality of our fresh, brackish and marine waters, for which wastewater management plays a particular role. The table below are the Significant Effluent Quality Parameters for Water Supply; Sewerage, Waste Management and Remediation Activities based from (DAO, 2016). Industry Category

Significant Parameters

Water collection, treatment and supply pH, Total Suspended Solids, (except those intended to prevent pollution) Fluoride,Iron

Chloride,

Sewerage (operation of sewer systems or BOD, Fecal Coliform, Ammonia, Nitrate, sewage treatment facilities that collect, treat, Phosphate, Oil and Grease, Surfactants and dispose of sewage) Treatment and disposal of non-hazardous Color, Temperature, pH, COD, Total waste Suspended Solids, Total Coliform, Ammonia, Nitrate, Phosphate, Sulfate, Chloride, Oil and Grease Treatment and disposal of hazardous waste

Color, Temperature, pH, COD, Total Suspended Solids, and other parameters depending on the nature of their activities

Remediation activities and other waste Color, Temperature, pH, COD, Total management services Suspended Solids, and other parameters depending on the nature of remediation activity Table 1: Significant Effluent Quality Parameters (DAO, 2016)

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F. Tuguegarao Public Market Don Domingo Tuguegarao Public Market, located along Balzain East, Tuguegarao City. it is the second public market in the city after the old Pamilihang Bayan ngTuguegarao which is now Mall of the Valley. However at present, it has no existing wastewater treatment plant. Thus, the construction of a MBR treatment facility is very important and can be very useful to the public market.

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CHAPTER 2 PROCESS DESCRIPTION AND SELECTION

Conventional wastewater treatment is currently widely used globally, however it has limitations since its scale is predominantly large and more capital investment is needed. As cited by Cele, 2014, it requires skill to operate which hinders its success in developing countries. Its implementation in remotely developed residential complexes is difficult since more capital investment is required; rural areas also experience a disadvantage from this technology since inhabitants are scattered. Amongst the technologies that have been developed for wastewater treatment is membrane bioreactors (MBRs). MBRs are increasingly being specified as a viable alternative for the reclamation of wastewater for reuse. According to Alibardi, 2015, Municipal wastewaters are, currently, mainly treated by the use of activated sludge systems which, although effective, require a great deal of energy. As a result, anaerobic technologies have been widely investigated for the treatment of municipal wastewater.

A. Market Wastewater As cited by Lazaro et al., 2014, wastewater from public markets is generated from distinct sources and activities. These include: meat, poultry, fish preparation and sales, fruit and vegetable sales prepared food stalls, and public restrooms. When combined into a common outfall, the resulting wastewater mixture typically contains high levels of organic material, suspended solids, fats, oils and grease. It commonly contains two to three times the organic matter and solids typically found in residential wastewater, classifying market sources as “high strength.”

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To effectively manage high-strength wastewater, treatment infrastructure must be designed and sized not only to address hydraulic loading in terms of volume (cubic meters per day), but also organic loading, which is expressed in terms of kilograms of BOD (Biochemical Oxygen Demand) per day, and solids loading, which is expressed in terms of Total Suspended Solids (TSS).

B. Treatment of Market Wastes Market wastewater containing high levels of organic material, suspended solids, fats, oils, and grease can be treated using the activated sludge process. Like the conventional process, wastewater will be passing through physical and biological treatment processes. 

Physical Treatment Coarse screens, particularly, mechanical bar screens, are used for screening large solids to lessen the labor costs and improve the flow conditions of the wastewater. It will also serve as the preliminary treatment for the wastewater before entering the primary sedimentation tank.



Biological Treatment Biological treatment process in an MBR begins after screening the wastewater. The

biological process takes place involving vigorous agitation, coming from air bubbles generated from a blower system. This acts to scour and clean the surface of the membrane to prevent buildup of a material and also to provide sufficient oxygen concentration for biological action that supports the growth of bacteria.

C. Membrane Filtration Membrane separation is currently used as support or replacement for traditional water and wastewater treatment technologies such as physical filtration or biological and chemical

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treatment. It is rapidly gaining acceptance throughout the world as the most effective and economical water treatment method available (Fraunhofer MOEZ). Membrane filtration, according to USEPA, involves the flow of wastewater containing pollutants across a membrane. Water permeates through the membrane into a separate channel for recovery (Figure 2.C). Because of the cross-flow movement of wastewater and the waste constituents, materials left behind di not accumulate at the membrane surface but are carried out of the system for later recovery or disposal. The water passing through the membrane is called permeate, while the water with the more-concentrated materials is called the concentrate. Membranes are constructed of cellulose or other polymer material, with a maximum pore size set during the manufacturing process. The requirement is that the membranes prevent passage of particles the size of microorganisms, or about 1 micron (0.001 millimeters), so that they remain in the system. This means that the MBR systems are good for removing solid material, but the removal of dissolved wastewater components must be facilitated by using additional treatment steps.

Figure2.C: Membrane Separation

D. Membrane Bioreactor 8

Membrane bioreactor (MBR)

is the combination of a membrane process like

microfiltration or ultrafiltration with a suspended growth bioreactor, and is now widely used for municipal and industrial wastewater treatment with plant sizes up to 80,000 population equivalent (i.e. 48 million liters per day). Membrane bioreactor technologies are those technologies that provide biological treatment with membrane separation. This is more appropriately applied to processes in which there is a coupling of these two elements, rather than the sequential application of membrane separation downstream of classical bio-treatment. Conventional treatment of municipal wastewater (sewage) usually proceeds through a three stage process: sedimentation of gross solids in the feed water followed by aerobic degradation of the organic matter and then a second sedimentation process to remove the biomass. An MBR can displace the two physical separation processes by filtering the biomass through a membrane. As a result the product water quality is significantly higher than that generated by conventional treatment, obviating the need for a further tertiary disinfection process (Judd,2008). Some advantages of MBRs over conventional processes include small footprint, easy retrofit and upgrade of old wastewater treatment plants. It is possible to operate MBR processes at higher mixed liquor suspended solids (MLSS) concentrations compared to conventional settlement separation systems, thus reducing the reactor volume to achieve the same loading rate. 1. Configurations of Membrane Bioreactor Two MBR configurations exist: internal/submerged, where the membranes are immersed in and integral to the biological reactor; and external/sidestream, where membranes are a separate unit process requiring an intermediate pumping step.

a.) Internal/submerged 9

The filtration element is installed in either the main bioreactor vessel or in a separate tank. The membranes can be flat sheet or tubular or combination of both, and can incorporate an online backwash system which reduces membrane surface fouling by pumping membrane permeate back through the membrane. In systems where the membranes are in a separate tank to the bioreactor, individual trains of membranes can be isolated to undertake cleaning regimes incorporating membrane soaks, however the biomass must be continuously pumped back to the main reactor to limit MLSS concentration increase. Additional aeration is also required to provide air scour to reduce fouling. Where the membranes are installed in the main reactor, membrane modules are removed from the vessel and transferred to an offline cleaning tank.

b.) External/sidestream The filtration elements are installed externally to the reactor, oftenin a plant room. The biomass is either pumped directly through a number of membrane modules in series and back to the bioreactor, or the biomass is pumped to a bank of modules, from which a second pump circulates the biomass through the modules in series. Cleaning and soaking of the membranes can be undertaken in place with use of an installed cleaning tank, pump and pipework.

Bioreactor influent

10 Effluent Treatedwater

Bioreactor

Sidestream membrane Effluent

influent Treated water wastewater Recirculation Airsparging(Aeration)

Figure 2.D.1. Internal MBR (top) and External MBR (bottom)

CHAPTER 3 11

DESIGN

The design of wastewater treatment plants is usually based on the need to reduce organic and suspended solids loads to limit pollution of the environment. Pathogen removal has very rarely been considered an objective but, for reuse of effluents in agriculture, this must now be of primary concern and processes should be selected and designed accordingly.

A. Wastewater Characteristics

An understanding of physical, chemical, and biological characteristics of wastewater is very important in design, operation, and management of collection, treatment, and disposal of wastewater. The nature of wastewater includes physical, chemical, and biological characteristics which depend on the water usage in the community, the industrial and commercial contributions, weather, and infiltration/inflow (Shun Dar Lin, 2007).

Market wastewaters are known to be high in organic content. They are also high in protein content from fish, poultry, and meat processing activities. These characteristics identify market wastewater from domestic wastewater. Desirable treatment must be conducted in order to decrease the organic content of the water before discharge or reuse.

1. Raw Wastewater Characteristics

The ff. data on the characteristics of the market wastewater are obtained through tests for the BOD5, COD, and TSS. The Average Design Flow is taken through estimation based on existing data of different wastewater flow of several public markets in the Philippines. The temperature is set to a standard of 200C (as cited by Lazaro et al., 2014).

Raw Wastewater Characteristics

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BOD5

1314 mg/L

COD

2240 mg/L

TSS

700 mg/L

Wastewater Temp.

20 0C

Average Design Flow

52.3 m3 /day

Table 3.A: Market Wastewater Characteristics B.Process Flow and Information The MBR Facility is installed after the process of Activated Sludge Tank to perform the separation volatile and semi-volatile organic compounds. The facility is a tool designed to remove biological and chemical waste products from water, thereby permitting the treated water to be used for other purposes. The proposed project will be placed at the Public Market. The MBR facility is a treatment process consisting of the following:

Screening is applied to remove the large inorganic and organic particles to prevent clogging of pipe lines and pumps. Since the wastewater contains high nitrogen content,Anoxic Tank isapplied to denitrify wastewater where the electron donor is carbon from domestic sewage and electron acceptor is nitrate. By denitrifying bacteria, nitrate will be converted to nitrogen gas which able to escape from the tank. Sludge will conveys to Activated Sludge Tank whichinvolves mixing air with the wastewater to provide the suitable condition for microorganisms to digest organic matter and nutrients to sustain their life process. To sustain the food to microorganism ratio, the treatment of domestic wastewater in the treatment facility was also included. During this phase, flocculation will take place by the slime layer of the bacteria, glycocalyx, and cause to bind them together with the wastewater. Biomass then conveys to the external MBR to separate and remove pathogens particularly fecal coliform and

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E. coli without applying disinfectant. Part of the biomass will return to the reactor. A high flow recirculation pump used for External MBR facility to utilize the membrane. Feed

MechanicalScreening

AnoxicTank

ActivatedSludgeTank

MBRFacility

Effluent

Figure 3.B: Process Flow of Wastewater Treatment C. Component of the Designed MBR Facility This section explains the required design parameter of the proposed project(Figure3.C). Each treatment phase is briefly explained to complete the facility. This component covers the idea of the designed MBR Facility from the start up to the ending conclusion.

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Figure 3.C: Proposed MBR Facility

1. Anoxic Tank An anoxic tank is a tank after primary screening where raw untreated wastewater enter and is being mixed for the equalization of sludge under the absence of oxygen. The size of the tank can be determined by the daily flow rate of sewage into the tank. The volume wastewater sample collected would be constant and its time would be variable. A sample will be collected on an hourly interval for 24 hours for the accuracy of the dimensions of the tank. This method is also applicable for solving the volume of an Equalization Tank.

2. Activated Sludge Tank In order to determine of size of the activated sludge tank, the flow rate of sewage in the public market must be identified. The Hydraulic Loading Rate (HLT) will then be solved. HLT is expressed as rate of flow in cubic meters per second over the surface area of the wet tank. This value is used to prevent the overflow of incoming wastewater in the aeration tank. 15

The Food to Microorganism Ratio (F/M) depends on the country’s climate. According to the stated standards, Philippines which lies under warm climate regions, the range generally lies between 5 days in warmer climates to 10 days in temperate ones. In this climate, nitrification is desired along with good BOD removal, and complete mixing systems are employed. Mixed Liquor Suspended Solids (MLSS) assumed to have a value of 2500 mg/l due to high level of MLSS clogging of membrane filter preventing the passage of permeate leading to failure and degradation of the effectiveness in the system treatment process. Furthermore, the volume of MLSS concentration will determine the HRT, or the number of hours that wastewater stay in the aeration tank to perform a complete aeration process.

D. Operational Parameters Parameters of the wastewater during and after treatment should always be considered in the design and operation as a guide in the design calculation and specifications of the treatment facility and equipment. According to DAO 35, effluent standards of Class B water must not be greater than 30 mg/L and 50 mg/L of BOD and Total Suspended Solids (TSS), respectively. These standards make the water suitable for bathing and cleaning. The table below is the Operational Parameters to be followed for the Design based from Shun Dar Lin, 2007.

Operational Parameters

Effluent BOD

≤ 30 mg/L

Effluent TSS

≤ 50 mg/L

Design Mean Cell Residence Time (θc)

5 days

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MLVSS

3000 mg/L

Yield Coefficient (Y )

0.5

Decay Constant (kd)

0.06 / day

BOD u BOD 5

0.67

MLVSS MLSS

0.8 Table 3.D: Operational Parameters

Assume: 

BOD and TSS removal in screening are 15% and 25%, respectively.



BOD and TSS removal in Equalization Tank are 30% and 55%, respectively.



Air weights 1.202 kg/m3 and contain 23.2% oxygen by weight



Oxygen transfer efficiency for air diffuser is 8% and safety factor of 2 is used to determine the actual volume for sizing the blowers.



S.G. of raw market wastewater is less than 2.65 and 4.5% of solid content



Oxygen consumption is 1.45 mg per mg of cell oxidized

E. Design Calculations 1. Screening Screening is first operation that the wastewater will be undergoing for treatment. It is a physical unit operation that removes large particles, such as paper, plastics, rags, that contributes to the clogging of pipes. It also helps in preventing damage to the equipment, piping, and other appurtenances downstream. The calculation of BOD and TSS entering the equalization tank is taken from the removal rate of the screen basket. With the aid of screens, about 15% and 25% of BOD and TSS is removed, respectively. (Lin 2007) Removal rate of BOD and TSS in screening: 17

BOD Loading: BOD loading = BOD5 Qave   mg 1 kg 1000 L  BOD loading  1314   52.3 m 3 / day 3  L 1,000,000 mg 1 m   BOD loading = 68.72 kg/day





TSS Loading: TSS loading = TSS Qave   mg 1 kg 1000 L  TSS loading  700   52.3 m 3 / day 3  L 1 , 000 , 000 mg 1 m   TSS loading = 36.61 kg/day





BOD removal:

BOD removed = BOD loading 15% removed    kg BOD removed  (68.72 )0.15 day   BOD removed = 10.31 kg/day TSS Removal:

TSS removed = TSS loading 25% removed    kg BOD removed  (36.61 )0.25 day   BOD removed = 9.15 kg/day

2. Equalization Tank After passing through the wire mesh basket, the wastewater enters an equalization tank. The equalization tank, from the term itself, equalizes the volume of wastewater entering the activated sludge tank and as well as the proceeding treatment processes. It prevents the passage of wastewater in the activated sludge tank in order not to disrupt the wastewater being aerated and also not to agitate the settling particles during the sedimentation process.

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An effective size of the tank must be strategically computed. Having a daily flow of 52.3 m3 per day and very small area for the tank, the volume of wastewater per treatment cycle must be able to contain. The average hourly flow rate is computed for 12 hours of market operation per day. The treatment facility can accommodate two (2) cycles of treatment per date having a Hydraulic Retention Time (HRT) of 12 hours. HRT is the number of hours the wastewater is being retained or held in the equalization tank. Given: Wastewater Influent

52.3 m3/day

Market Operation

12 hrs

Cycles of Treatment per Day

2 cycles per day

Hydraulic Retention Time



12 hrs

Average hourly flow rate during operation: m3 52.3 m3 day  4.36 12 hrs. hr.



Since the MBR treatment operation takes 12 hrs V  Qt





V  4.36 m 3 / hr. 12 hrs.  V  52.32 m



3

Let the depth be 3m with a free board of 0.6 m , and the length and width to have a ratio of 3:1. Calculate the width and depth:

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V  L WD Length  3Width  52.32 m 3  3W W 3m  3W 2 

52.32 m 3 3m

W = 2.4 m L= 7.2 m



Calculate the depth with freeboard of 0.6 meters D = 0.6 m (free board) + 3 m D = 3.6 m L × W × D = 7.2 m × 2.4 m × 3.6 m



Calculate for the remaining BOD and TSS from screening entering the equalization tank.  BOD Remaining: BOD remaining = 68.72 kg/day - 10.31 kg/day BOD remaining = 58.41 kg/day

 TSS Remaining: TSS remaining = 36.61 kg/day - 9.15 kg/day TSS remaining = 27.46 kg/day According to the Water and Wastewater Calculations Manual, 30% of BOD and 55% of the COD entering the equalization tank is retained. The other percentage of these values passes through and enters the activated sludge tank. The sludge flow rate (SFR) is also subtracted since it will also be retained in the equalization tank. The SFR

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is the amount of sludge that has settled on the bottom of the equalization tank. The sludge that settled below the tank is pumped out with the use of a sludge pump.  BOD Removal: BOD removed = (58.41 kg/day)(30%) BOD removed = 17.53 kg/day

BOD remaining = BOD loading-BOD removed BOD remaining = 40.89 kg/day

 TSS Removal: TSS removed = (27.46 kg/day)(55%) TSS removed = 15.10 kg/day

TSS remaining = TSS loading-TSS removed TSS remaining = 12.36 kg/day

 Sludge Flow Rate:

SFR 

TSS Removed S.G  D water  %solid content

SFR 

15.10 kg/day 2.65  1000 kg/m 3  0.045

SFR  0.13 m 3 /day

3. Activated Sludge Tank The activated sludge tank is where the wastewater is converted into its reusable form and decanted into a water tank for storage and reuse. The entire process of aeration, settling, and membrane filtration takes place in this tank. 21



Dimensions of the Tank The computations below must be followed in order to come up with the

volume and dimensions of the tank.  Flow of the BOD and TSS in Activated Sludge Tank Q in  Q ave - SFR Q in  52.3m 3 /day - 0.13m 3 /day

Q in  52.17 m 3 /day 50% will only proceed  Q in  26.09 m 3 /day

 BOD Loading - BOD removed  BOD in  50%   Q in    58.41 kg/day - 17.53 kg/day  BOD in  50%   26.09 m 3 /day   BOD in  0.7834kg/m 3 BODin = 783.44mg/L So = 783.44mg/L

 TSS Loading - TSS removed  TSS in  50%   equalizati on Q in    27.46 kg/day - 15.10 kg/day  TSS in  50%  26.09 m 3 /day   TSS in  0.23687kg/ m 3 TSSin=236.87mg/L

 Estimation of Soluble BOD5 that will enter to the membrane. To estimate, determine the BOD5 of the effluent suspended solids assuming 85% biodegradable solids and 1.45 mg of oxygen is consumed per mg of cell oxidized. Biodegradable Effluent Solids = (Effluent BOD5)(% biodegradable) = (30 mg/L)(85%) = 25.5 mg/L 22

BODu of Bio. Eff. Solids = (25.5mg/L)(1.45 mg O2/ mg cell) = 36.98 mg/L BOD5 = 0.67 (BODu) = 0.67 (36.98 mg/L) = 24.8 mg/L ←approx. twice the BOD5

COD = 2 (BOD5) = 2 (24.8 mg/L) = 49.6 mg/L

Effluent BOD = influent soluble BOD + BOD of eff. suspended solids 30 mg/L= S + 24.8 mg/L S = 5.22 mg/L



Dimensions of the Aeration Tank A minimum depth of 3 meters was set. But since the rate of flow is very low, the value must be accepted. A free board of 0.6 m is also added and the length to width ratio must be 2:1.  Calculating the width and depth

V  L WD Length  2Width  26.09 m 3  L W D  26.09 m 3  2W W 3 W = 2.1 m L = 4.2 m  Calculate the depth with free board of 0.6 m D = 3 m + 0.6 m D = 3.6 m

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L × W × d = 4.2 m × 2.1 m × 3.6m V = 31.752 m



Hydraulic Retention Time HRT 

V Q in

31.75m 3 52.3m 3 /day HRT  0.6 day

HRT 

HRT ≈𝟏𝟐𝐡𝐫𝐬

4.Oxygen Requirements Calculating the oxygen requirements gives the amount of air needed to be injected per day of aeration. Its theoretical requirements are taken from the BOD5 and the concentration of microorganisms that should be present in the wastewater per day. For the theoretical air requirements, the biomass yield observed and the sludge production per day must be calculated.

 Q S - S BOD used   in o   0.67   26.09m 3 /day 783.44mg/L - 5.22mg/L  1000 L  1kg   6  BOD used    3  0.67   1m  10 mg  BOD used  30.3kg/day

5. Sludge Wasting Sludge wasting is very essential in activated sludge treatment. It is the amount of sludge that is removed per day in the tank. The tank must contain a sufficient amount of sludge to support the growth of microorganisms. The following steps are to be followed in calculating for the sludge wasted. 24



Sludge Wasting Flow Rate



V MLVSS 



c     Q SW MLVSS   Q O X E  





  31.75m 3 3000mg/L  5days    3  QSW 3000mg / L   26.09 m /day(50mg/ L  0.8  Q SW  6.0m 3 /day 

The increase in mass of MLSS (Py) from the increase of MLVSS production (Px=7.81 kg/day) as computed. Px 7.81 kg/day  0.80. 0.80. Py  9.76 kg / day Py 



Calculate TSS lost in the effluent (PL) PL= (Qin−Qsw)(Effluent TSS) = ( 26.09 m3/day− 6.00 m3/day)(50mg/L) PL= 𝟏.𝟎𝟎𝟒𝟓𝐤𝐠/𝐝𝐚𝐲



Estimate the quantity of sludge to be wasted daily. Wastewater sludge= Py−PL Wastewater sludge= 9.76 kg/day−1.0045 kg/day Wastewater sludge= 𝟖.𝟕𝟔𝐤𝐠/𝐝𝐚𝐲

6. Membrane Design Assuming the Design Flow is 20 L/hr-m2 and the Standard Filter Area is 25 m2. 

Computing for daily permeate flow per cycle:

  L 1 m3 12 hr Q P  20    25 m 2  5 cassetes  2  hr  m 1000 L 1 cycle  = 30 m3/cycle

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CONCLUSION The study entitled “Wastewater Treatment in Public Market using External Membrane Bioreactor” is able to design an advanced treatment facility for discharging an effluent complying with standards as stated in DAO 35. Different biological and physical treatments applied to the wastewater resulted to an effluent passing the standards for bathing, cleaning and etc. Membrane Bioreactors provides an advanced level of wastewater treatment making it sufficient for reuse. Since the expected effluent quality is water classification class C, the treatment provided an effluent overly meeting the said requirement with the production of class B water. As to this, the public market can therefore, use the treated water as a water supply for human recreation. The construction of the facility would be of great benefit for the market and in the promotion of sustainable development, and a healthy and pollution free environment for everybody.

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REFERENCES 

Alibardi, N. Bernava, R. Cossu, A. Spagni, (2015).Anaerobic dynamic membrane bioreactor for wastewater treatment at ambient temperature, Chemical Engineering Journal



Cele, Mxolisi Norman,2014.Development and Evaluation Of Woven Fabric Immersed Membrane Bioreactor For Treatment Of Domestic Waste Water For Re-Use.



DAO, D. A. (2016, March 30). Water Quality Guidelines and General Effluent Standards of 2016. Department of Environment and Natural Resources , pp. 1-25.



FraunhoferMoez.Membrane Technologies for Water and Wastewater Treatment on the European and Indian Market



Judd, Simon,2008. The status of membrane bioreactor technology.



Lazaro, L. S., Miura, A. R., & Perez, I. C. (2014). Design of a Membrane BioReactor (MBR) Facilityfor Treating Market Wastewater Using Hollow Fiber Ultrafiltration Membrane. Mapúa Institute of Technology, 20.



Rakesh Kumar, R. N. (2006). Municipal Water and Waste Water Treatment. The Energy and Resources Institute (TERI).



ShunDarLin,2007.Water and Wastewater Calculation Manuals 2nd Ed.



T.Subramani, Porkodi, D., & Jayalakshmi, J. (2014). Sewage Treatment In Salem District. IOSR Journal of Engineering (IOSRJEN), 08-13.

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TERM PAPER PRESENTATION In Industrial Waste Management and Control (Written Report)

TOPIC: _________________________________________________________________________________________________

PRESENTER: ___________________________________________

Unacceptable

Marginal

Exceptional

(1)

(3)

(5)

Criteria Organization & Style

Score Little or no structure or organization; no subheadings or proper paragraph structure

Material are generally organized well, but paragraphs combine

Organizes written materials in a logical sequence to enhance

Used

multiple thoughts or sections and subsections are not identified clearly

the reader's comprehension

Uncomfortable with content. Only basic concepts are demonstrated and interpreted.

Demonstration of full knowledge of the subject with explanations and elaboration.

(2) Content & Knowledge

No grasp of information. Clearly no knowledge of subject matter. No questions are answered. No interpretation made.

(3)

29i

(paragraphs, subheading, etc.)

Application of Engineering

No application of engineering and/or scientific principles

Serious deficiencies in proper selection and use of engineering principles.

Critical selection and application of engineering principles ensuring reasonable results.

Principles (4) Documentation (2)

Design is done Incompletely without the proper equations and

Design is done, but procedures and equations are not documented or referenced

Supports design procedure with

Seeks no extra information other than what is provided by instructor

Seeks information from a few sources mainly from the textbook or the instructor

Seeks information on problems from multiple resources

Graphs, tables or diagrams are used, but no reference is made to them

Uses graphs, tables, and diagrams, but only in a few instances are they applied to support, explain or interpret information

Uses graphs, tables, and diagrams to support points-to explain, interpret, and assess information

Several spelling and grammatical errors.

Minor misspellings and/or grammatical errors.

Negligible misspellings and/or grammatical errors.

No figures or graphics are used at all

Figures are present but are flawed-axes mislabeled, no data

Figures are all in proper format

without references Outside Resources

documentation and references

(2) Use of Supporting Graphs, Tables, etc (3)

Spelling & Grammar (1) Figure Formatting (1)

points, etc

30

References (2)

Inadequate list of references or references in text. Inconsistent or

Minor inadequacies in references. Consistent referencing system.

illogical referencing system.

Reference section complete and comprehensive. Consistent and logical referencing system.

TOTAL

Rater:

____________________________________

Signature: _________________________________

Date: _____________________________

31

TERM PAPER PRESENTATION In Industrial Waste Management and Control (Oral Presentation)

TOPIC: _________________________________________________________________________________________________

PRESENTER: ___________________________________________

Unacceptable

Marginal

Exceptional

(1)

(3)

(5)

Criteria

Delivery (2) Length and Detail

Score Talk is poorly organized, e.g. no clear introduction or summary of talk is Presented

(4)

Plans and delivers an oral presentation effectively; applies the principle of "(tell them)" –well organized

Presentation is inappropriately short or excessively long; omits key results during presentation

Presentation contains excessive or insufficient detail for time allowed or

Major difficulties with the mechanical aspects of the presentation. No eye contact. Difficult to hear or understand speaking. Reads from prepared

Has some minor difficulties with the mechanical aspects of the presentation. Eye contact is sporadic. Occasionally difficult to hear or understand speaking. Overuses prompts or does not use prompts enough

(3) Mechanics

Presents key elements of an oral presentation adequately, but "tell them" not clearly applied

level of audience

32

Presentation has enough detail appropriate and technical content for the time constraint and the audience

Presents well mechanically. Makes eye contact Can be easily heard. Speaks comfortably with minimal prompts (notecards). Does not block screen. No distracting nervous habits

Dialect

Script. Blocks the screen. Distracting nervous habits (um, ah, clicking

occasionally stumbles or loses place; appears to

pointer, etc.)

have memorize presentation. Occasionally blocks screen Some nervous habits (um, ah, clicking pointer, etc.)

Uses poor English

Occasionally uses an inappropriate style of English-too conversational

Uses proper American English

Multiple slides are unclear or incomprehensible

Visual aides have minor errors or are not always clearly visible

Uses visual aids effectively

Inappropriate attire, slovenly or too revealing

Appearance is too casual for the circumstances

Professional appearance

Does not listen carefully to questions, does not provide an appropriate

Sometimes misunderstands

Listens carefully and responds to questions appropriately; is able

(2) Visual Aides (2) Appearance (3) Listening and Response to

answer, or is unable to answer questions about presentation material

Questions

questions, does not respond appropriately to the audience, or has some trouble answering questions

to explain and interpret results for various audiences and purposes

(4) TOTAL

Rater:

____________________________________

Signature: _________________________________

Date: _____________________________

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