A presentation required for the course of Advance Industrial Microbiology (MCB260) at University of the Philippines. An overview of waste water treatment process. Some policies in the Philippines were cited. BOD and COD were explained and the Microorganisms involve in different types of bioreactors and wastewater treatment are also briefly describe.

1. Prepared by: Elijah M. Avante
MS Microbiology 2012-98147
WASTE TREATMENT

2. WHAT IS WASTEWATER?
 domestic sewage or liquid industrial waste
that cannot be discarded in untreated form
into lakes or streams due to public health
 Industrialsources: –dairy, food, pharmaceutical
etc. (~1500 BOD units)
 Domestic sources: – Form households and non-
industrial businesses (~200 BOD units) (Madigan et
al.,2012)

3. WASTEWATER TREATMENT
 majority of wastes generated by humankind
were disposed of directly into the
environment. (Waites et al., 2001)
 employs physical and chemical methods as
well as industrial-scale use of
microorganisms. (Madigan et al., 2012)

4. WHY TREAT WASTEWATER?
 So that they can be safely discharged
directly into the environment (rendering them
chemically and biologically harmless) (Waites et al.,
2001)
(http://musicminers.org/)

5. SEWAGE
 liquid effluent contaminated with human or
animal fecal materials
 may also contain potentially harmful
inorganic and organic compounds as well as
pathogenic microorganisms (Waites et al., 2001)
(waterdesalinationplants.com)

6. On average, each person in the United States
uses 100–200 gallons of water every day for
washing, cooking, drinking, and sanitation. (Madigan
et al.,2012)
(http://sadmanstongue.com)

7. SCREENING FOR SUITABLE TREATMENT
 Before establishing the most suitable method for
treating and disposing of any given pollutant,
analytical methods are required to assess the
polluting strength of the waste.
 Biochemical Oxygen Demand (BOD)
 Chemical Oxygen Demand (COD)
 Total Organic Carbon (TOC)
 Total Suspended Solids (TSS)
 Total Solids (TS) (Waites et al.,2001)

8. BIOCHEMICAL OXYGEN DEMAND (BOD)
 The efficiency of treatment is expressed in
terms of a reduction in the biochemical
oxygen demand (BOD)
 High levels of organic and inorganic
materials in the wastewater result in a high
BOD (Madigan et al.,2012)

9. BOD
 The BOD test estimates the amount of
oxygen required by aerobic microorganisms
to oxidize biodegradable material in polluted
waste-waters over a fixed period of time
(normally 5 days), at constant temperature
(20°C) in the dark (prevents the possibility of
photosynthetic (algae) production of DO) (Waites
et al.,2001)

10. BOD
 ―Seed" bacteria
 bacteria from receiving waters (rivers, ponds)
 soil suspensions
 raw wastewater *most commonly used
 lypholyzed commercial seed

12. BIOLOGICAL OXYGEN DEMAND (BOD)
(http://www.hach.com)

13. CHEMICAL OXYGEN DEMAND (COD)
 Because of the drawback of BOD test having
a long incubation period required Chemical
Oxygen Demand test was developed
 This determines the amount of oxygen
required to chemically oxidize any oxidizable
material present in a wastewater

14. COD
 Each test involves adding a known volume of
sample to a mixture of oxygen-rich potassium
dichromate and concentrated sulfuric acid.
 This is refluxed for 2–4h and the residual
concentration of dichromate is determined by
titration with ferrous sulfate or ferrous
ammonium sulfate.
 The concentration of oxidizable compounds is
proportional to the potassium dichromate
utilized and the results are expressed in
milligrams of oxygen per liter.

15. COD
(www.news.thomasnet.com

16. COD VS BOD
 BOD only measures the amount of oxygen consumed
by microbial oxidation and is most relevant to waters
rich in organic matter.
 COD and BOD do not necessarily measure the same
types of oxygen consumption.
 COD does not measure the oxygen-consuming potential
associated with certain dissolved organic compounds
such as acetate. However, acetate can be metabolized
by microorganisms and would therefore be detected in
an assay of BOD.
 In contrast, the oxygen-consuming potential
of cellulose is not measured during a short-term BOD
assay, but it is measured during a COD test.
(http://science.jrank.org)

17.  The overall efficiency is in the order TDS <
COD < TSS < BOD in Mailasandra STP
while in Nagasandra STP, it is TDS < COD <
BOD < TSS.

18. COD VS BOD
 COD values are always higher than the BOD
values. Because COD includes both
biodegradbale and non-biodegradable
substances whereas BOD contains only bio-
degradable.
 BOD analysis is performed mainly to satisfy
permit requirements.
 COD measured provides a quantitive estimate
of everything currently in the waste stream that
can be oxidized. *thereby permitting closer operational control of
the treatment process (Abdul et al., 2012)

19. WASTE TREATMENT PROCESSES
 The aerobic/anaerobic self-purification
sequence that occurs when organic matter is
added to lakes and rivers can be carried out
under controlled conditions in which natural
processes are intensified (Willey et al.,2008)

20. PRIMARY TREATMENT
 Physically removes 20 to 30% of the BOD
that is present in particulate form.
 In this treatment, particulate material is
removed by screening, precipitation of small
particulates, and settling in basins or tanks.
 The resulting solid material is usually called
sludge (Willey et al.,2008)

21. SECONDARY TREATMENT
 promotes the biological transformation of
dissolved organic matter to microbial
biomass and carbon dioxide.
 About 90 to 95% of the BOD and many
bacterial pathogens are removed by this
process (Willey et al., 2008)

22. SECONDARY ANAEROBIC WASTEWATER TREATMENT
 a series of degradative and fermentative
reactions carried out by various prokaryotes
under anoxic conditions.
 used to treat wastewater containing large
quantities of insoluble organic matter (and
therefore having a very high BOD) such as
fiber and cellulose waste from food and dairy
plants (Madigan et al.,2012)

23. SECONDARY ANAEROBIC WASTEWATER TREATMENT
(Madigan,2012)

24. SECONDARY ANAEROBIC WASTEWATER TREATMENT
(Madigan et al.,2012)

25. (Madigan et al.,2012)

26. SECONDARY AEROBIC WASTEWATER TREATMENT
 uses oxidative degradation reactions carried
out by microorganisms under aerobic
conditions to treat wastewater containing low
levels of organic materials
 wastewaters that originate from residential
sources can be treated efficiently using only
aerobic treatment (Madigan et al.,2012)

27. SECONDARY AEROBIC WASTEWATER TREATMENT
 These systems are of two types
 Trickling Filter System - sewage is sprayed over a
bed of rocks (coated with a slimy film of aerobic
organisms such as Sphaerotilus and Beggiatoa) and
removes about 80% of the organic matter in the
water
 Activated Sludge System - the effluent from primary
treatment is constantly agitated, aerated, and added
to solid material remaining from earlier water
treatment (Black,2012)

28. TRICKLING FILTER SYSTEM
(Willey et al.,2008)

29. (ETI,1998)

30. AERATION
 The underdrain system is designed to meet
two objectives:
 collecttreated wastewater
 create a plenum that allows for the transfer of air
throughout the trickling filter media. (Daigger & Boltz,2011)

31. AERATION
 The vertical flow of air through trickling filter
media can be induced by mechanical
ventilation or natural air draft.
 Mechanical ventilation enhances controls airflow
with low-pressure fans that continuously circulate
air throughout the trickling filter.
 Adequate underdrain and effluent channel
permits free airflow. (vent stacks ventilating
manholes or louvers on the sidewall of the tower)
(Daigger & Boltz,2011)

32. SLOUGHING
 As the layer thickens (with microbial growth),
oxygen cannot penetrate to the media face,
and anaerobic organisms develop. As the
biological film continues to grow, the
microorganisms next to the surface lose their
ability to cling to the media, and a portion of
the slime layer falls off the filter. This is
known as sloughing and is the main source
of solids picked up by the underdrain system.
(ETI,1998)

33. BIOMASS CONTROL
 Mechanical removal
 Backwashing can be applied only with no-fluidizing
packing. After any mechanical removal, biotrickling
filters require some days to reach the elimination
capacities they had before the treatment. *Simple and
effective but also very expensive
 Chemical Removal
 First attempts were carried out with NaOH(0.1M)
solution in toluene degrading bioreactor
 NaOH, sodium dodecylsulphate, NaN3, NaClO, H2O2,
ethanol, saturated iodine, NH3 and HCO are the
chemicals often use in chemical treatment. Many of
these attempts completely deactivated the biomass.
NaClO seems to be the most promising chemical.
(Della

34. ACTIVATED SLUDGE SYSTEM
(Willey et al.,2008)

35. AERATION
 Supplying the required oxygen to the organisms to
grow and providing optimum contact between the
dissolved and suspended organic matter and the
microorganisms.
 Mechanical aerators physically splash the wastewater
into the atmosphere above the tank and create
turbulence assuring effective wastewater mixing.
brushes, blades or propellers that introduce air from
the atmosphere. Surface aerators float at the surface
or are mounted on supports in or above the basin.
Mechanical aerators tend to incur lower installation
and maintenance costs. (Pipeline,2003)

36. AERATION
 A diffused air system introduces compressed
air through a perforated membrane into the
wastewater. Diffusers are classified by the
physical characteristics of the equipment, or
by the size of the air bubble. The choice of
bubble size, diffuser type, and diffuser
placement can have a great effect on the
efficiency of the aeration process. (Pipeline,2003)

37. FLOC FORMED BY AN ACTIVATED SLUDGE SYSTEM
(Case et al.,2011)

38. SOME MICROORGANISMS INVOLVE IN AEROBIC
WASTE TREATMENT
 Bodo sp.
 Vorticella sp.
 Actinophrys sp.
 Euplotes sp.
 Nematoda
 Mastigophora sp.
 Zoogloea sp.
*The organisms that can be found in a trickling filter do not differ much
from the ones found in activated sludge

39. BULKING
 Occasionally, the sludge will float rather than
settle out and this will result into bulking
 Organic matter in the floc flows out with the
discharge effluent, resulting in local pollution.
 Sphaerotilus natans
 Nocardia sp.
(Case et al.,2011)

40. BULKING
 Here are several methods on treating bulking
on the activated sludge system.
 Chlorination - chlorine and hydrogen
 Flushing – high water pressure to clean the tank
 Distillation and pH Titration Method – treating
septicity
*Adjust parameters for to prevent bulking
(Richard,2003)

41. DIFFERENT PROCESS FOR WASTE TREATMENT
 Fixed film processes — microorganisms are
held on a surface, the fixed film, which may be
mobile or stationary with wastewater flowing
past the surface/media. These processes are
designed to actively contact the biofilm with the
wastewater and with oxygen, when needed
 Suspended growth processes — biomass is
freely suspended in the wastewater and is
mixed and can be aerated by a variety of
devices that transfer oxygen to the bioreactor
(Schultz,2005)

42. FIXED-FILM OPTIONS
 Biotowers (trickling filters)
 Rotating biological contactors
 Submerged biological contactors
(Schultz,2005)

43. ROTATING BIOLOGICAL CONTACTORS
 consist of vertically arranged, plastic media
on a horizontal, rotating shaft
 biomass- coated media are alternately
exposed to wastewater and atmospheric
oxygen as the shaft slowly rotates at 1–1.5
rpm
(Schultz,2005)

44. ROTATING BIOLOGICAL CONTACTORS
(Schultz,2005)

45. SUBMERGED BIOLOGICAL CONTACTORS
(www.sswm.info)

46. SUBMERGED BIOLOGICAL CONTACTORS
 operate at nearly 90% submergence with
coarse-bubble diffused aeration providing a
means of both aeration and motive force for
rotation

47. SUSPENDED-GROWTH OPTIONS
 Diffused aeration
 Jet aeration
(Schultz,2005)

48. DIFFUSED AERATION
(www.brightwaterfli.com) (www.ecosafeindia.com)

49. JET AERATION
(Schultz,2005)

50. DIFFUSED AERATOR
 Diffused aerators add air to wastewater,
increasing dissolved oxygen content and
supplying microorganisms with oxygen
necessary for aerobic biological treatment
(Schultz,2005)

51. JET AERATION
 It is designed to provide required aeration as
well as maintain suspension of biological solids,
with the flexibility to either aerate or mix
independently without the need for additional
equipment
 When air is not available pumps provide the
required mixing action
 Since jet aeration requires no moving parts in
the basin, the system offers long life with no in-
basin routine maintenance required
(Schultz,2005)

52. (Black,2012)

53. SLUDGE DIGESTION
 Primary sludge - accumulates in primary
sedimentation tanks
 Sludge - accumulates in activated sludge
and in trickling filter secondary treatments
 Undergo further treatment in a anaerobic sludge
digester
 The process of sludge digestion is carried out in
large tanks from which oxygen is almost
completely excluded
(Case et al.,2011)

54. SLUDGE DIGESTION
 There are essentially three stages:
 The first stage is the production of carbon dioxide
and organic acids from anaerobic fermentation of the
sludge by various anaerobic and facultatively
anaerobic microorganisms.
 In the second stage, the organic acids are
metabolized to form hydrogen and carbon dioxide,
as well as organic acids such as acetic acid.
 These products are the raw materials for a third
stage, in which the methane-producing bacteria
produce methane (CH4).
(Case et al.,2011)

55. (Case et al.,2011)

56. SLUDGE DIGESTION
 After anaerobic digestion is completed, large
amounts of undigested sludge still remain.
 To reduce its volume, this sludge is pumped to
shallow drying beds or water-extracting filters.
 can be used for landfill, as a soil conditioner or
fertilizer (biosolids)
 Classified as class A & B which means doesn’t
contain any pathogen and the one that has and
needs to be treated because of the presence of
pathogens
(Case et al.,2011)

57. DRYING BED
(http://www.defence.gov.au)

58. TERTIARY TREATMENT
 Fine sand and charcoal are used in filtration
and involves physical and chemical methods
 Chlorine or Ultraviolet Light is used to
destroy any remaining organisms (Black,2012)

59. (Black,2012)

61. MICROBIAL FUEL CELLS
 Directly generating electricity from organic
matter in wastewater, while simultaneously
treating the wastewater
 Electrons released by bacterial oxidation of the
organic matter are transferred through the
external circuit to the cathode where they
combine with oxygen to form water.
*Treatment was examined here in terms of
maximum power densities, Coulombic efficiencies
(CEs), and chemical oxygen demand (COD)

62. MFC
(http://www.sciencedaily.com)

63. MFC
 In the first step of the MFC, an anode
respiring bacterium breaks down the organic
waste to carbon dioxide and transfers the
electrons released to the anode.
 Next, the electrons travel from the anode,
through an external circuit to generate
electrical energy.
 Finally, the electrons complete the circuit by
traveling to the cathode, where they are
taken up by oxygen and hydrogen ions to
form water.

64. MFC
 At COD concentrations of 200 and 350 mg/L,
the maximum power densities with the
brewery wastewater were 53 and 63 mW/m2,
respectively.

65. MEDICAL WASTE
 Covers all wastes produced in health-care or
diagnostic activities
 75 % to 90 % of hospital wastes are similar
to household refuse
(International Committee of the Red Cross,

66. (International Committee of the Red Cross,

67. (International Committee of the Red Cross,

68. METHODS OF TREATING MEDICAL WASTES
 Incineration
 Chemical Disinfection
 Autoclaving
 Needle Extraction or
Destruction
 Shredders
 Encapsulation
 Disposal in a sanitary
landfill or waste burial pit
(International Committee of the Red Cross, (www.health.ny.gov

69. METHODS OF TREATING MEDICAL WASTES
 chemical: addition of disinfectants (chlorine
dioxide, sodium hypochlorite, peracetic acid,
ozone, alkaline hydrolysis
 irradiation: UV rays, electron beams
 biological: enzymes
 Thermal:
 low temperatures (100° to 180°C): vapour
(autoclave, micro-waves) or hot air (convection,
combustion, infrared heat)
 high temperatures (200° to over 1000°C):
incineration (combustion, pyrolysis and/or
gasification);

70. METHODS OF TREATING MEDICAL WASTES
 mechanical processes: shredding (a process
which does not decontaminate the waste)
 encapsulation (or solidification) of sharps
 burial: sanitary landfills, trenches, pits.

71. WASTE MANAGEMENT IN PHILIPPINES
 Republic Act (RA) No. 9003 (―The Ecological
Solid Waste Management Act of 2000‖)
 Department of Environment and Natural
Resources (DENR) Administrative Order
(DAO) No. 2001-34, the Implementing Rules
and Regulations (IRR) of RA 9003. (Manila Standard
Today,2005)

72. LA MESA TREATMENT PLANT
(http://www.mayniladwater.com.ph

73. PUTATAN TREATMENT PLANT
(http://www.mayniladwater.com.ph

74. DENR & DOH
 Toxic Substances, Hazardous Waste, and
Nuclear Waste Control Act of 1990 [Republic Act
6969]
 Ecological Solid Waste Management Act of
2000 [Republic Act 9003]
 Clean Water Act of 2004 [Republic Act 9275]
 Hospital Licensure Act [Republic Act 4226] (Manila

75. (http://www.pwp.org.ph)

76. REFERENCES
 Waites, M.J, Morgan, N.L. Rockey, J.S. & Higton, G. (2001). Industrial Microbiology: An
Introduction. USA: Blackwell Science Ltd.
 Madigan, M.T., Martinko, J.M., Stah, D.A. & Clark (2012). Brock Biology of Microorganism. San
Francisco, CA: Madigan Education, Inc.
 Willey, J.M., Sherwood, L.M. & Woolverton, C.J. (2008). Prescott,Harley, and Klein’s
Microbiology. New York: The McGraw-Hill Companies, Inc.
 Robinson, T., & Singh Nigam (2008). Remediation of Textile Dye Waste Water using a white-Rot
Fungus Bjerkandera adusta. Applied Biochemical Biotechnology 15: 618-628.
 Black, J.G. (2012). Microbiology: Principles and Explorations. USA: John Wiley & Sons, Inc.
 Abdulkareem, A.S. (2004). Modeling of Microbial Growth in a Wastewater Treatment Plant: A
Case Study of Textile Industry in Kaduna, Nigeria. AU J.T. 8(1): 45-54.
 Davies, P.S. (2005). The Biological Basis of Wastewater Treatment. Kelvin Campus, West of
Scotland Science Park Glasgow G20 0SP, UK Strathkelvin Instruments Ltd
 International Committee of the Red Cross (2011). Medical Waste Management. shop@icrc.org
www.icrc.org
 Gozun, E.G. (2003) Handbook On The Ecological Solid Waste Management Act Of 2000 (RA
9003) and Its Implementing Rules and Regulations (IRR). Manila: The Philippine Environmental
Governance Program, Department of Environment and Natural Resources.