A FACTORY VISIT TO THE
DEPARTMENT, UCH, IBADAN.
ENVIRONMENTAL
HEALTH
OBJECTIVES OF THE VISIT:
 To have a vivid knowledge of the activities done at the environmental health
science department.
 To learn how and understand how waste is being handled, treated and
disposed at the incineration site.
 To understand the science behind purifying the dirtiest of water so it can go
back into the environment as a member in good standing of the water cycle.

HISTORY OF
DEPARTMENT
THE
ENVIRONMENTAL
HEALTH
SCIENCE
Environmental Health Department was formerly known as health department and it
was established in March 1958. It was one of the departments that had been
established from the inception of the hospital. It was under the preventive and social
medicine department before it became autonomous in October 1958.
In 2006 to 2007, when some reform activities were done in Nigeria, Environmental
Health Department was part of the reformed departments and environment healthrelated work like cleaning of the hospital and waste management were outsourced
to private contractors.
In March 2011, the former CMD, Professor Temitope Alonge restored
Environmental health as a new unit under Total Facility Management Department
which was later changed to Works department. In 2013, Mrs. Bukola Akerele
became the head of the unit up until July 1st 2020 when the Board of Management
approved the reinstatement of the department and I was pronounced the head of the
department.
The leadership of this department goes as far back as 1958, from 1958-1978 Mr. A.
Adesola; Mr. A.A. Babatunde 1978-1986; Mr. J.O Oladosun 1987-2007. In 2011
when the Environmental health unit was restored under the Total Facility
Management Department, Mr. A.A. Adewumi and Mrs. Bukola Akerele were the
two sanitarians that started the unit. The department has close to a 100 staffs or more.
The objective and goal of the department is to maintain a standard hygienic
environment for quality healthcare delivery in line with the vision of the Hospital
which is to be the flagship of healthcare institution in West-Africa sub-region. The
Environmental Health Department duty is to ensure adequate waste disposal, sewage
treatment, pest control and flood control by adequate evacuation of blocked
drainages and also monitor contract staffs that are still around.
The tour guide during the visit to the environmental health science department was
anchored by Mrs. obisesan adefolake and Mrs. Mustapha where they shared in
details what the department does and how activities are being done. The first aspect
that was looked into was the incineration site then later the waste water treatment
facility.
THE PROCESS AND
INCINERATION SITE:
PROCEDURES
EMPLOYED
AT
THE
Arriving to the Incineration Plant first we listened to a short presentation about its
history and then took a walk around the site. They have very strict rules about which
waste can go into the site and the use of personal protective equipment (PPE) was
being emphasized on.
The incineration site is where waste is being managed in the hospital. It has a special
way of handling, treating and disposing of waste. There are two broad categories of
waste in the hospital setting at UCH, Ibadan are;
 NON HAZARDOUS (GENERAL WASTE)
This type of waste is generated in offices and residential buildings and that
does not cause harm to people or the environment. The Waste can be offensive
but not hazardous in nature.
 HAZARDOUS WASTE
hazardous waste is a waste with properties that make it dangerous or capable
of having a harmful effect on human health or the environment. Hazardous
waste is generated from many sources, ranging from industrial manufacturing
process wastes to batteries and may come in many forms, including liquids,
solids gases, and sludge.
Household hazardous wastes can include anything corrosive, chemical-based,
pesticides among others. It is important for households to be sure these are
stored and disposed of properly.
The classification of hazardous waste at the incineration site are as follow:
 Highly infectious waste
 Infectious waste
 Pharmaceutical waste
 Radioactive waste
 Sharp waste
 Chemical waste
At the incinerator plant, there were three incinerator machines used and has the type
of waste that should go into it.
 INCINERATOR 1; used for handling pathological waste
 INCINERATOR 2 (electrically driven); used for handling highly infectious
waste
 INCINERATOR 3 (manually driven); used for handling hazardous waste.
PROCESS OF HOW THE GENERAL WASTE IS BEING HANDLED AND
TREATED.
SORTING
In this stage, waste segregation is being carried out. It is a method of keeping
wet and dry wastes separately, so that dry can be recycled and wet waste can
be composted. Known contractors are being contacted to come and retrieve
the recycle waste and use them for other products. Contractors take the
recyclables to be recycled into pellets as raw materials.
Other parts of the non-hazardous waste such as food waste, paper are loaded
into trucks to government approved dumpsites. UCH Ibadan, uses the
dumpsite located at awotan-apete, Ibadan.
PROCESS OF HOW THE HAZARDOUS WASTE IS BEING HANDLED
AND TREATED.
 The hazardous waste is being carefully handled and the best method to deal
with it is by incineration. The hazardous wastes are not being sorted and it
goes straight into the incinerator on getting to the site. it comes from different
segments of the hospital like the theatre, laboratories, labor wards. Groupings
are done to classify what waste are found under the various types of hazardous
waste:
1. SHARP BOX: needles, syringes are being found in the sharp box
2. PATHOLOGICAL WASTE: It contains body parts for example
amputated legs or arms and mass burial is carried out for these type
of waste which is done at a place called akufor.
Another way to know which of the waste to tamper with, grouping is done by the
color of nylons the waste is being found in:
 RED NYLON: this contains highly infectious waste which could come from
the theatre and these type of waste cannot be sorted.
 YELLOW NYLON: this contains infectious waste which comes from the
laboratory
 BLACK NYLON: this contains general waste and can be sorted out.
Products of the incineration is being added to the waste going to the dumpsite for
disposal.
THE SECOND ASPECT OF THE FIELD TRIP WAS A VISIT TO THE
SEWAGE TREATMENT PLANT.
This is where the liquid waste is being sorted and treated. The liquid waste comprises
of sullage and sewage. the primary objective of the sewage treatment plant is to
ensure that waste water generated is safe before being released into the surrounding
water bodies. The general processes of sewage treatment are primary, secondary and
tertiary treatment. Primary treatment involves physical separation of sewage into
solids and liquid . The liquid sewage is then transferred to secondary treatment which
focuses on removing the dissolved biological compound by the use of microorganisms. The micro-organisms usually use aerobic metabolism to degrade the
biological matter in the liquid sludge. Then tertiary treatment is required to disinfect
the sewage so that it can be released into the environment.
The contaminants typically found in untreated wastewater are grouped into four
basic classes which are: organic contaminants, inorganic contaminants, pathogens
and other contaminants.
ROLE OF A SEWAGE TREATMENT PLANT TO THE ENVIRONMENT:
 Sewage treatment plant helps in putting the brakes over water pollution thus
giving a stable hold to maintain the balance in the ecosystem.
 It reduces organic material and pollutants by the controlled action of helpful
bacteria and other microorganisms that consume organic matter in
wastewater.
WHAT IS A SULLAGE:
It is also called grey water and it refers to domestic wastewater generated in
households or office buildings from streams without fecal contamination, i.e., all
streams except for the wastewater from toilets. Sources of greywater include sinks,
showers, baths, washing machines or dishwashers.
WHAT IS SEWAGE:
It is also called black water and it is generated in toilets and also contain some flush
water besides urine and excreta. Blackwater can contain feces, urine, water and toilet
paper from flush toilets.
CHARACTERISTICS OF SEWAGE;
it is grouped into three which are physical, chemical, and biological characteristics.
PHYSICAL CHARCTERISTICS
1. Temperature:


Temperature of sewage depends upon season. However, temperature is slightly
higher than that of ground water.
High temperature of sewage is due to evolution of heat during decomposition
of organic matter in sewage.
2. Color:


Color of sewage indicates its strength and age.
Fresh domestic sewage is grey in color but septic sewage is dark in color
3. Odor:
Fresh domestic sewage is almost odorless.
Septic or stale sewage is putrid in odor which is due to generation of H2S during
anaerobic decomposition of organic matters.


4. Turbidity:


Sewage is highly turbid.
Turbidity of sewage is due to dissolved substances, colloidal matters,
suspended solids and microbial cells.
II. CHEMICAL CHARACTERISTICS OF SEWAGE:
1. Organic matter:


In general sewage contains large amount of organic matters. However,
amount of organic matter depends on types and condition of sewage.
Organic matter in sewage may be found in the form of dissolved substances,
colloidal matter, suspended or in sediment form.
2. Chloride:




Human beings discharge large amount (8-15gm/day) of chloride in the form
of NaCl, especially through urine and sweat. So domestic sewage from toilet
and bathroom contains higher level of chloride.
Sulfite:
In sewage sulfite in the form of H2S (hydrogen sulfite) is generated during
anaerobic decomposition of organic matters by anaerobic bacteria.
H2S gives putrid odor to sewage.
3. Biological oxygen demand (BOD):


Sewage usually have high BOD due to presence of large amount of organic
matters.
Value of BOD ranges from 100mg/litre for very dilute sewage to 600mg/litre
4. Dissolved oxygen (DO):


Due to high level of microbial cells and biodegradable organic matters,
sewage have very low level of dissolved oxygen. In some sewage, DO is
completely absent.
Level of Do depends on age and condition of sewage. Low level DO is also
due to lower solubility of oxygen in sewage. Oxygen is only 95% soluble in
sewage than in pure water).
5. pH:

sewage is slightly alkaline in pH
6. Nitrogen:



In sewage nitrogen is found in variety of form like organic nitrogen, ammonia,
nitrite, nitrate etc
Fresh sewage mainly contains organic nitrogen and very little inorganic form
of nitrogen. On the other hand, organic septic sewage contains high inorganic
nitrogen and low organic nitrogen.
In sewage nitrite never accumulate in concentration greater than 1mg/ltr
because it is intermediate product during conversion of ammonia into nitrate
(NO3). In sewage treatment plant, NH3 and NO2 are finally converted to NO3.
7. Oxidation-Reduction (O-R) potential:



Oxidation-Reduction potential indicates energy state of sewage in terms of its
oxidizing or reducing potential.
O-R potential is very valuable index to monitor sewage treatment plant.
In aerobic treatment process like tripling filters, positive OR potential of about
+2 to +600 is needed. In anaerobic treatment process like sludge digestion,
negative OR potential of about -100 to -200 is needed.
III. Biological characteristics of sewage:
1. Bacteria:

Two types of bacteria are found in sewage.
 Intestinal bacteria:
 Non-pathogenic intestinal bacteria are normal flora of
gastrointestinal tract of human and animals and enter into sewage
together with stool. Examples; feacal coliform, feacal
streptococci, Clostridium perfingens.
Pathogenic intestinal bacteria such as Salmonella, Shigella,
Vibrio cholera, Yersenia enterocolitica etc enter into sewage
through stool of patients.
Real sewage bacteria
 The natural habitat of these bacteria is sewage. Both aerobic as
well as anaerobic bacteria are found in sewage.
 Aerobic bacteria play important role in oxidation of organic
matter during aerobic process. Examples of Common anaerobic
bacteria includes;
 Clostridium sporogens
 Bifidobacterium
 Peptococcus
 Methanogenic
bacteria
like
Methanobacterium,
methanosarcina
 Common aerobic bacteria include;
 Zeoglea remigera
 Noacrdia
 Flavobacterium
 Achromobacter
 Nitrosomonas

Zeoglea remigera is the main organism found in trickling filter.


2. Algae:

Some algae found in sewage includes Chlorella phormidum, Ulothrix etc.
3. Fungi:

Fungi like Fusarium and Sporotricum are found in sewage which play
important role in trickling filter.
4. Virus:

Some viruses causing human disease such as Poliovirus, Rotavirus, Hepatitis
A and E etc. are found in sewage which get access through stool of patients.
5. Protozoa:

Some protozoa that cause disease of intestinal tract enter into sewage together
with stool of patient.


Examples: Entamoeba histolytica, Giardia, Balantidium coli etc. are
pathogenic protozoa
Few protozoa such as Vorticella and Opercularia are found in trickling filter.
PRIMARY TREATMENT STAGE PROCESS OF SEWAGE TREATMENT
Any form of solids are removed, e.g. pads. There is a collection box within which
the screen bar and the communitor shred solids into liquids. Rake is used to rake any
solid in the face of the screen bar.
After the collection box, waste water goes to the primary settling tank where sludge
settles at the bottom and clearer effluent in the middle and floatable particles at the
top.
SECONDARY
TREATMENT
TREATMENT
STAGE
PROCESS
OF
SEWAGE
Here trickling filter beds are used and the waste water enters through the base of the
filter beds. The filter bed is arranged in layers; the biggest stones are layered at the
base while the smallest stones at the top layer of the filter bed. The water enters the
base through a gadget on the filter bed (watering) and water is being sprinkled on
top of the bed surface which filters and cleans the effluent going to the next stage.
The stones used in the trickling filter beds are always removed and set back after
proper cleaning.
Aeration tanks: they contain aerators which are like fans.one rotates in a clockwise
manner and the other in an anticlockwise manner causing agitation which is a way
of making the water to gain enough oxygen to help aid the microorganisms in water
gain enough organic matter to produce a clearer effluent.
TERTIARY TREATMENT STAGE
The treatment carried out here is to compensate for anything that has not been taken
care of at the secondary treatment stage. The tertiary treatment stage is called the
final settling tank and in this tank there is no agitation or aeration. The water is
allowed to settle down and accumulated sludge are evacuated and used as fertilizers.
The water goes through a chlorine dosing tank and chlorine is added and stirred for
proper mixing before disposal into the environment.
ANOTHER SECTION OF THE ENVIRONMENTAL HEALTH SCIENCE
DEPARTMENT IS THE LABORATORY
The mini laboratory runs a full analysis to check the quality of the wastewater that
is about to be discharged into the environment. It checks for the physical, chemical
and biological parameters of the wastewater in order to know the quality of the
wastewater being discharged and the quality of treatment methods used.
After the analysis have been carried out, standard for wastewater is being used to
compare with the actual figures to know if its within limits or have exceeded the
maximum limits and adjusts can then be made.
GENERAL OBSERVATIONS MADE DURING THE VISIT:

Workers were not using the appropriate protective wear and this can pose a
serious problem to the health of the workers due to the toxins produced by
health care wastes.
RECOMMENDATIONS
 Flame retardant clothing – including gloves, arm guards, jackets and coveralls
are all essential pieces of PPE. These help minimize any potential risk if stray
sparks, incinerated material or simmering ash lands on an operator.
 Awareness should be done on a regular basis on the essence of the use of PPE
when at the plant or within the premises.
 Proper monitoring and supervision should be put in place during the
segregation of waste
 The 3R’s should be imbibed as one of the ethics of recycling at the plant in
order to reduce the amount of waste being taken to the dumpsites.
 Personal protective equipment should be worn at all times.
CONCLUSION
The visit to environmental health science department wastewater treatment plant and
incineration site was an educative and informative field
The Visit which gave an insight on how wastewater is being treated and made safe
for the environment and also for use and also proper handling and sorting and
disposal of waste.