physico-chemical and heavy metal analysis of effluent

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6

Physico-Chemical and Heavy Metal Analysis of Effluent Water from Port Harcourt Refinery Depot, Nigeria

Abstract: Physico-chemical and heavy metal analysis of effluent water from Port

Harcourt Refinery Company Ltd. was done. Water samples were collected from

the fall out (station 1), 100m away (station 2) and 200m away (station 3) and

taken to the laboratory for analysis. The pH for station 1=5.0, station 2=5.5 and

station 3=6.0 which is below the DPR specification. The electrical conductivity

ranged from 60-75µS/cm. The TDS values of station 1 and 2 were recorded as

19mg/L and station 3 was 20mg/L. Salinity was low in all stations. The TSS was

above the DPR specification at station 1 but at station 2 and 3 was within the

specification of 30mg/L. BOD was high in all stations and was above the DPR

specification of 10mg/L, the result ranged from 28-43mg/L. The value of COD

exceeded the DPR specification of 40mg/L, the result for all stations ranged from

42-61mg/L. The level of oil and grease in station 1 and 2 were higher than the

DPR specification of 10mg/L but station 3 was observed to be within. The heavy

metals (Lead (Pb), Nickel (Ni), Manganese (Mn), Cadmium (Cd) and Chromium

(Cr)) were estimated using Atomic Absorption Spectrophotometer. The result

obtained for Pb in station 1=0.051mg/L, station 2=0.062mg/L and station

3=0.030mg/L. Ni in station 1=0.009mg/L, station 2=0.001mg/L and station

3=0.012mg/L. Mn, Cd and Cr were=0.001 in all. Pb was observed to be higher

than all other heavy metals in the effluent water.

Keywords: Effluent water, physico-chemical parameters, heavy metals, refinery.

INTRODUCTION Nigeria is blessed with a vast gas and crude oil deposits and exploring it has

left the country with vulnerabilities (Nduka and Orisakwe, 2009). There is a

strong relationship between human activities and pollution of the environment.

The recognition of this connection and the need to protect human health,

recreation and fisheries production led to the early development of water quality

regulation and monitoring methods (Daka et al., 2007; USEPA, 1986). Industrial

effluents, agricultural run offs, transport, burning fossils, animal and human

excretes, contribute to the metal level in water bodies (Altindag and Yigit, 2005;

Awofolu et al., 2005; Adeniyi and Okedeyi, 2004). Rapid urbanization and

industrialization of Port Harcourt and its environs between 1965 and 2003 created

pollution potentials that are high. The rivers estuaries, creeks and air have been contaminated for decades (Egborbe, 1995). The Port

Harcourt Refinery at Alesa Eleme has a processing capacity of producing 60,000 barrels of petroleum per day of crude oil. Nigerian

Crude is known to contain heavy metals in varying proportions (Nwadinigwe and Nworgu, 1999). The metallic components in crude

oil are in the form of transition metal complexes, organometallic compounds, carbonyl acid salts of polar functional groups,

metalloporphyrin chelates and colloidal minerals (Lewis and Sani, 1981). Other inorganic constituents of crude oil are Sulphur,

Nitrogen, Lead, Cadmium, Chromium and Manganese (Achi and Shide, 2004). Discharge of some metals into natural waters at

increased concentration in sewage, industrial effluents or from mining and industrial operations can have severe toxicological effects

on aquatic environment and humans (DWAF, 1996). These environmental pollutants which are environmentally mobile tend to

accumulate in organism and become persistent because of their chemical stability or poor biodegradability (Emoyan et al., 2005).

Heavy metals gain access into the river system from both natural and anthropogenic sources and these get distributed into the water

body and sediment during the course of their transport. A catchment area containing solid minerals will usually have elevated metal

level as the trace metal content of the river waters is normally controlled by the abundance of metals in the river catchment and their

mobility (Olajire and Imeokparia, 2000). In coastal environments, the influence of salt water intrusion is often significant.

Underground water quality is dependent on pollution status of its environment (Olabaniyi and Owoyemi, 2006). The subsurface flow

system of the Niger Delta is complex as the braided nature of the streams and rivers there in (Ekundayo, 2006), coupled with the

problems of environmental pollution, degradation, river situation, coastal erosion as well as extermination of wildlife, fauna and flora

that are of the fate of oil bearing communities in the Niger Delta region. The Port Harcourt Refinery makes it more noticeable that

these problem by discharge of its untreated effluents into natural receptors (adjoining surface waters) hence the essence of this study is

to ascertain the pollutant loads of water in the study area (Ekerekana creek) with a view of comparing the pollution profile of the water

supply of the coastal creek areas in Port Harcourt in order to assist policy makers and regulatory agencies on policy issues.

Research Article

Article History

Received: 05.09.2020

Accepted: 02.10.2020

Revision: 07. 10.2020

Published: 10.10.2020

Author Details Orodu, Victor Enearepuadoh., and

ALALIBO, Minainyo Emmanuel

Authors Affiliations

Department Of Chemical Sciences, Faculty Of Science, Niger Delta University P.M.B 071, Wilberforce Island, Bayelsa. Nigeria

Corresponding Author* Orodu, Victor Enearepuadoh

How to Cite the Article: Orodu, Victor Enearepuadoh., and ALALIBO,

Minainyo Emmanuel (2020); Physico-

Chemical and Heavy Metal Analysis of

Effluent Water from Port Harcourt Refinery

Depot, Nigeria. Int Aca. J App Biomed Sci.

1(1)6-17.

Copyright @ 2020: This is an open-access article distributed under the terms of the Creative Commons Attribution license which permits unrestricted use, distribution, and reproduction in any medium for non commercial use (NonCommercial, or CC-BY-NC) provided the original author and source are credited.

Orodu, Victor Enearepuadoh., and ALALIBO, Minainyo Emmanuel; Int Aca. J App Biomed Sci; Vol-1, Iss- 1 (Sep-Oct, 2020): 6-17

7

Port Harcourt Refining Company Ltd, is an oil

refinery and the problems of pollution arising at oil

refinery with the main emphasis on effluent water. Oily

water can accumulate from variety of process units and

the immediate surroundings of tanks and pump houses

plus water drained from tanks; process water and

chemical draining. The nonoil containments which

appear are sulphides, ammonia, organic acid, phenols,

sodium chloride and other inorganic salt are likely to be

present in the crude oil tankage and desalter. These

compounds are toxic to aquatic organism if discharged

to the sea without treatment. The physico-chemical,

biological and geological characteristics of water

determined gives us its usefulness for industry,

domestic and agricultural uses. The study of water

chemistry gives the important indications of geological

history of the enclosing rock, the velocity and direction

of water movement (American Public Health

Association, 2012). In developed countries, strict

adherence to standards is maintained to ensure good and

efficient pollution control. Industrial effluents are

treated to very low levels of toxicity before discharge

into the environment. However, in developing countries

like Nigeria, there is no strict adherence to antipollution

standard but with establishment of Federal

Environmental Protection Agency (FEPA), there is a

ray of hope. This poses a threat to human existence if

not checked, since pollution effect on man are

cumulative (American Standard for Testing Material,

1997). Waste water is a Refinery effluent from various

units of the Refinery and passes through treatment

before discharging into Ekerekena creek then into the

ocean. There is a great need for proper control of waste

treatment process to ensure very low toxic levels of

pollution discharge into receptor environment. Water is

an extraordinary substance, anomalous in nearly all of

its physical-chemical properties and easily the most

complex of all the familiar substances that are single

chemical compounds. The physico-chemical properties

of water are of great importance. Pure water has no

taste, odour or turbidity. At one atmosphere of pressure

pure water has the following properties; molecular

weight 18.01, density of 0.998g/mol, vapour pressure of

4.58mmHg melting point of 00C, boiling point of

1000Cand heat of ionization of 55.71kg/mL. One

property that makes water such a good solvent is that it

is not linear but rather tetrahedral making it have a

strong dipole moment. Water is never entirely 100%

pure as it carries traces of other substances which

bestow to its physical, chemical and bacteriological.

Port Harcourt Refining Company Ltd, is an oil

company which provides qualitative refining services

for domestic and internal markets at competitive prices.

Port Harcourt Refining Company Ltd, is a subsidiary of

Nigeria National Petroleum Cooperation (NNPC) and

its Nigeria’s biggest Refinery sited at Alesa Eleme, one

of the suburbs of Port Harcourt in Rivers State.

Contaminants such as phenol, mercaptan, sulphides,

ammonia, organic compounds and inorganic salts are

present in crude oil tankage and desalting. The

pollution of water by industries located within urban

settlements is a cause of concern in most parts of the

world (Nyamangara et al., 2008; Rajaram and Das,

2008). Pollution by heavy metals occurs from

industries, agricultural wastes and automobile exhausts.

Many of these wastes are toxic and the heavy metals

found their ways to land, water and sediments. These

problem is worse in developing countries where rapid

urban population growth and increased industrialization

has increased the hydraulic lead and complexity of

effluents handled by public owned treatment work

(POTW) (Oberholster et al., 2008; Ntuli T et al., 2011).

STUDY AREA The sample area for this study is indicated in

the figure below. Port Harcourt Refinery Company Ltd.

is located in a region of Rivers State in Nigeria with its

geographic coordinates are 4o45’33”N, 7

o05’53”E at

Alesa-Eleme. Ekerekana is one of the towns that make

up Okrika local government area of Rivers state. It is

host to Nigeria’s biggest refinery and petrochemical

company established in 1978, with a processing

capacity of 60,000 barrels per day of crude oil. The host

community that donated their land jointly for the

establishment of the company was AlesaEleme in

Rivers state. The surface water of the host communities

receives effluents directly from the company. The area

experiences tropical climate with significant rainfall in

most month of the year. The average annual

temperature of 250C


8

Figure1. Map showing the sample location

Collection of Samples

The samples were collected from Port Harcourt

Refinery fall out on the 21st of March 2019 around

2:00pm. The samples were then transported to

JachPetroanalytical Company in a cooler with ice in it

to maintain the temperature of the samples.

Name of Samples

Samples were collected directly from the fall out(station

1), 100m away (station 2) and 200m away (station 3).

Heavy metals determined: Lead, Manganese,

Chromium, Cadmium, Nickel

Materials and Instruments

water samples (from 3 stations), sampling

bottles, spatula, weighing balance, pH meter (model HI

98107), conductivity meter (model DDS-307), digestion

flask, hot plate, plastic bottles, atomic absorption

spectrometer (shimadzu AAS-6300), burette,

spectrophotometer (model 7000 UV spec), distillation

apparatus, wash bottles, distilled water, volumetric

flask, pipettes and reagents.

METHODS The method used for sampling and laboratory

analysis is according to the America Standard Testing

Material (ASTM), American Petroleum Institute (API)

and Petroleum Institute of India (PII). The parameters

monitored for toxicity levels of refinery effluents are;

pH, Temperature, Electrical conductivity, Oil and

grease, Total dissolved solids, Total suspended solids,

Biochemical oxygen demand, Chemical oxygen

demand, Cyanides, Salinity, Metals: Nickel, Lead,

Manganese, Cadmium and Chromium.

Parameters of Pollution Monitored in Refinery

Effluent

Pollution parameters are generally used for

characterizing the various forms of pollutants. The

parameters are largely dependent on the sources of

effluents whereas domestic sewage contains impurities.

These parameters of pollution in refinery effluents can

be classified under physical, chemical and microbial

qualities.

Physical Parameters

This are generally reported in terms of temperature,

colour, odour, turbidity and pH

a) Temperature: The temperature of the water

samples monitored is in degree centigrade. The

temperature of the refinery wastewater in warm

climate is slightly lower than air temperature

during most of the year and it has effect on

microbial activities.

b) pH: This is the negative logarithms base 10 of

hydrogen ion concentration(pH=-log10[H+]). The

pH of refinery wastewater was monitored with a

pH meter and made sure it was accordance with the

international standard before being discharged.

c) Turbidity: This is caused by a variety of

suspended and colloid solids. The turbidity is

expressed in the form of total dissolve solids and

conductivity.

d) Electrical conductivity and resistivity of water: The unit electrical conductivity is Siemens per

centimeter. The actual resistance of the cell Rx is

measured in Ohms. The conductance 1/Rx is

directly proportional to the length of the path L

(cm). 1/Rx=K*A/L where K is the conductivity and

expressed in millisiemens/centimeter at a specified

temperature normally at 25oC.

e) Electrical Resistivity: Resistance in Ohms

measured between opposite faces of centimeter

cube of an aqueous solution at specified

temperature[Rx=R*L/A]. The values are usually

expressed in Ohm centimeter at a specified

temperature of 25oC.

Chemical Pollution Parameters

In refinery waste, there are mainly organic and

inorganic constituents including fat and grease. The

constituents are stable and decomposed slowly by

microorganisms. Organic constituents are monitored by

Biochemical oxygen demand(BOD) and Chemical

oxygen demand(COD), phenolic compounds and

cyanides. Inorganic parameters are acidity and

alkalinity, chloride, phosphate, ammonia and heavy

metals. All these are monitored to make sure that they

are within FEPA specifications before they are

discharged into sea.

Laboratory Analysis

Determination of Total Suspended Solids in Water

a) Summary of method: The total matter is

determined by evaporation of an appropriate

aliquot or the particulate are separated by filtration

and dried and weighed.

b) Method: 100mL of water samples was measured

and filtered through 0.45µm filter membrane.

Before filtration, the filter paper was dried in oven

at 105oC and cooled in the desiccator and weighed.

The particulate matter was dried and weighed.

c) Calculation:

Total suspended solids=

ie

Result expressed in ppm or mg/L d) Significance: It is important for biologically

treated effluents and for many industrial wastes.

The suspended matter is largely organic and thus

responsible for significant proportion of the oxygen

demand. Thus if discharged to steam it would

consume undesirable amount of dissolved oxygen.


9

Determination of Oil and Grease

a) Scope: This is to determine the oil and grease in

water by gravimetric method.

b) Procedure: 200mL of the wastewater sample was

placed in 300mL separating funnel and acidified

with 5mL of conc. HCl. 40mL of CCl4 was added

and shaken vigorously for extraction. The pressure

was always released at intervals; the 100mL beaker

was dried and weighed. The CCl4 layer was filtered

though a filter paper containing anhydrous sodium

sulphate into a known weight 100mL beaker. The

anhydrous sulphate is to remove the traces of water

from oil. The beaker and the contents were placed

on a hot plate in a fume cupboard evaporated to

dryness. The beaker was removed and cooled in a

dessicator for 30mins before reweighing.

c) Calculation:

Oil/grease

content=

ie

d) Significance: The presence of oil and grease in

domestic and industrial wastewater is of concern to

the public because of its deleterious aesthetic

effects and its impacts on aquatic life. Regulation

and standards have been established that requires

monitoring of oil and grease in wastewater. Oil and

grease standard in water is 0.5ppm.

Determination of Phenolic Compounds by Direct

Colorimetric Method

100mL of the distillate was transferred to

100mL volumetric flask or suitable aliquot diluted to

100mL. Blank was prepared with 100mL of distilled

water measured into 100mL volumetric flask. 5mL of

NH4OH solution was added to the 100mL distillate and

adjusted the ph 9.8-10.2 with NH4OH. 2mL 0f 4-amino

antipyrine and 2mL of Potassium ferric cyanide was

added and mixed vigorously. The mixture was left for

15mins for colour development. The mixture was later

scan at 510nm with10mm absorption cell. The colour

intensity is proportional to the amount of the phenolic

compounds present in the sample.

Calculation: Conc. from UV dillutor factor =Phenol

mg/L or ppm

Determination of Cyanide

Scope: The method covers the determination of total

cyanide in water and saline water

Significance: The presence of cyanide in industrial,

domestic and surface waters is of concern because of its

toxicity.

Summary of methods: This is based on the

decomposition of nearly all of the metalo-cyanide

complexes and simple cyanides from a strongly

acidified sample during a one hour reflux distillation

procedure. To ensure the breakdown of the very tightly

complexed iron cyanide compounds; a decomposition

catalyst magnesium chloride is added to the sample

before distillation. The cyanide content of the

absorption solution is determined colourimetrically.

Procedure: 250mL of water sample were collected in

500mL beaker and 20mL of Zinc acetate into 500mL

distillation flask and refluxed for 1hr. The distillation

was collected in a 100mL cylinder containing 20mL of

sodium hydroxide (0.04N)

The sodium hydroxide absorbed the cyanide and

converted to sodium cyanide 10mL 0f the aliquot was

collected in 50mL volumetric flask. 4mL of phosphate

buffer, 2mL of chloramines T and 5mL of pyridine

solution were added into the sample and development

and measures with 10mm absorption cell at 578nm.

For blank monitoring, 10mL of 0.04N 9f NaOH was

collected in 50mL volumetric flask and other reagents

were added and scan at 578nm.

Reagents: Phosphate k buffer, anhydrous sodium,

hydrogen phosphate, 3N NaH2PO4.H2O, (138g/L).

Barbatric pyridine preparation: 15g Barbaric into a

250mL volumetric flask and 75mL pyridine and mixed

vigorously. 15mL of HCl was added to the mixture and

cool to room temperature, then diluted to mark with

distilled water and mixed until all the barbituric acid

has completely dissolved.

Calculation ppm

µg/50mL=

50/10=Aliquot in 50mL

100mL=Distilled collected

250g-quality of the sample

Determination of Chemical Oxygen Demand using

Digital (COD) Meter

Scope: This method describes a procedure for the

determination of the total oxidizable material in

Refinery effluent and other industrial waste water

Definition: COD is the amount of oxygen consumed

under prescribed test condition in the oxidation of

organic matter in waste water

Outline: The COD meter is the testing set for COD

measurement based on test method of industrial

effluent.COD is an index of organic contamination in

factory effluent which can ne measured through a

simple operation by colometry titration. The PPM is

digitally given on the meter.

Principle: A certain quantity of KMnO4(Potassium

Permanganate)is added to a water sample and after its

acid heating reaction by H2S04 the residual KMnO4

which remains without reacting to the organic matter in


10

the water sample is made to react with Ferrous ions by

electro-reduction is detected by an indicator electrode

which is directly indicated on the display for COD

value. Hence the amount of oxidizable material is

directly proportional to KMnO4 consumed.

Reagents: H2SO4/FeNH4(SO4)2: 60g of Ammonium

Ferric Sulphate into 400mL of distilled water and 5mL

of concentrated sulphuric acid.

N/40 KMnO4 solution: 0.8g of KMnO4 into 1litre of

distilled water and store in amber bottle.

Electrode internal solution: Dilute 3.0g KCl into 100mL

distilled water.

Determination of Biochemical Oxygen Demand

(BOD)

Definition: BOD is the oxygen consumed for biological

depredation.

Summary of Method: This is a biological procedure,

which attempts to stimulate the natural processes of

oxidation of organic matter occurring in a river or

stream. The test is carried out by suitably diluting the

sample with aerated water and divides the diluted

sample between two bottles.

The dissolved oxygen is determined immediately in one

bottle and in the second bottle after it has been

incubated as a standard temperature of 20oC for 5 days.

The period of 5 days is the time at which the rare

oxygen consumption would attain a minimum value

under natural condition.

Many industrial effluent contain toxic metals phenolic

compounds, cyanides which depress the oxidation of

organic matter and reducing compound and organic

compounds not early amendable to biological oxidation,

thus making the BOD test unreliable.

Reagents

Seeding reagents are :

i) Solution A=FeCl3(0.25g/l)

B=CaCl2(27.5g/1)

C=MgSO4(22.5g/1)

D=K2HPO4(21.75G/1)

KH2PO4(8.5G/1)

Na2HPO4(44.6g/l)

NH4Cl(1.7g/l)

ii) MnSO4(240g/500mL) (solution 1)

iii) KOH 350g, Kl 75g, NaN3 10g/500mL (solution

2)

iv) Na2S2O3.5H2O 6.205g/L

v) KlO3 3.567g/L

vi) Arrow starch

Procedure: Seeding water was prepared by collecting

5000mL of distilled water and 1% of treated Biodisk

water sample added. 5mL of the solution A, 4mL of B,

5mL of C and 5mL of solution D were added to the

5000mL distilled water and aerated for 1hr.

About 3 BOD bottles were used and various

dilutions were used for the samples with the seeding

water, in each of the bottles containing both samples

and seeding water. 1mL of Manganese Sulphate was

added to convert the oxygen present at Manganese (iv)

oxide and 1ml of (KOH, KI and NaN3) solution was

also added to precipitate the sample Manganese

hydroxide.

The excess oxygen liberated was then titrated with

0.025N of Na2S2O3 with starch solution as indicator.

Calculation: BOD is calculated as Dissolved Oxygen

Dissolved

Oxygen=

)

BOD= Where T=Titre value of Na2S2O3

Factor for BOD

20mlLof 1/40N KIO3+5mL of (1:5H2SO4)

+Starch solution. Keep in dark for 5mins

Titrate the solution with 1/40N Na2S2O3

N1V1=N2V2

0.025g KIO3×20=0.025g Na2S2O3×V2 Na2S2O3

Factor=20/V2=

For example

To calculate for BOD of an observation pond

Dissolved oxygen=

Determination of Heavy Metals

Scope: To determine the toxicity level of heavy metals

in the effluent.

Summary of Method: The samples were digested with

HCl and into solution with distilled water. The solution

was scanned at various wavelengths with Atomic

absorption spectrophotometer.

Procedure: The samples was digested with 5mL of

concentrated HCl, some water was added and filtered to

remove particles. The digested solution was transferred

into a 100mL volumetric flask and filled to mark.

Different metals where scanned at various wavelengths.

The metals observed are: Nickel (Ni) at 248.3nm, Lead

(Pb) at 217.0nm, Manganese (Mn) at 279.48nm,

Cadmium (Cd) at 228.8nm and Chromium (Cr) at

357.9nm.


11

RESULTS 3.1.1 Presentation and Analysis of Result

Parameter DPR Specification Refinery fall out

(station 1)

100m away

(station 2)

200m away

(station 2)

pH 6.5-8.5 5.0 5.5 6.0

Conductivity(us/cm) NO LIMIT 74.9 71.9 60.4

Temperature (0C) 35 32.3 32.3 22.4

TDS 2000 19 19 20

Chlorine (mg/L) 250 21.3 24.85 14.2

Salinity (ppt) 600 0.0278 0.0266 0.0218

TSS (mg/L) 30 31.65 30.56 26.44

BOD (mg/L) 10 28.65 40.75 42.56

COD (mg/L) 40 42.55 59.70 60.79

Phenol (mg/L) 0.001 0.05 0.041 0.040

Oil and grease (mg/L) 10 13.62 12.72 10.51

Cyanide (mg/L) NO LIMIT <0.001 <0.001 <0.001

Heavy Metals in Refinery Effluents

The heavy metals in Port Harcourt Refinery effluent was monitored, the findings is tabulated below.

Parameters DPR Specification Refinery fall out

(station 1)

100 away

(station 2)

200 away

(station 3)

Nickel (mg/L) NO LIMIT 0.009 <0.001 0.012

Lead (mg/L) 0.05 0.051 0.062 0.030

Manganese (mg/L) NO LIMIT <0.001 <0.001 <0.001

Cadmium (mg/L) NO LIMIT <0.001 <0.001 <0.001

Chromium (mg/L) <0.001 <0.001 <0.001 <0.001

Fig 3.1 showing pH levels of the different sampled sites. Acidity was noticed to be weakening. Tending toward neutrality.


12

Fig 3.2 showing conductivity of the different sampling points. DPR does not have a limit.

Fig 3.3 showing the temperature of the different sampled sites. Temperature was observed to decrease as you move away from refinery

fall station 1 =2>3.

Fig 3.4 showing TDS. It was observed to be very minute/insignificant when compared with the DPR standard for all the

sampling sites.


13

Fig 3.5 showing the chloride levels for all the sampled sites. It was found to be infinitesimal when compared to the DPR

standard.

Fig 3.6 showing the salinity levels for all the sampled sites. It was found to be infinitesimal when compared to the DPR standard.

Fig 3.7 showing the TSS levels for all the sampled sites. It was found to be above in station 1 and 2 when compared to

the DPR standard but lower in station 3


14

Fig 3.8 showing the BOD levels for all the sampled sites. It was found to be higher for all the sampled sites as you move

further from station 1 to station 3, when compared to the DPR standard.

Fig 3.9 showing the COD levels for all the sampled sites. It was found to be higher for all the sampled sites as you move

further from station 1 to station 3, when compared to the DPR standard


15

Fig 3.10 showing the phenol levels for all the sampled sites. It was found to be higher for all the sampled sites when

compared to the DPR standard. As you move further from station 1 to station 3, it started reducing.

Fig 3.11 showing the oil and grease levels for all the sampled sites. It was found to be higher for all the sampled sites

when compared to the DPR standard. As you move further from station 1 to station 3, oil and grease level started

decreasing

Fig 3.12 showing cyanide. It was observed to be very minute/insignificant


16

Fig 3.13 showing Heavy metals at all Stations. Lead and Nickel were observed to be high when compared with the DPR

standard for all the sampled sites

DISCUSSION The level of both the metallic and non-metallic

pollutants of this study showed a range of variations.

This can be attributed to the differential derivations of

these inorganic pollutants from the discharge of

untreated water effluents originated from industries.

Heavy metals are harmful to most organisms at some

level of exposure and absorption (Chan et al., 1995).

The physico-chemical properties measured in

the study are pH, temperature, conductivity, TDS,

chlorine, salinity, TSS, BOD, COD, phenol, oil and

grease, cyanide and some heavy metals such as Nickel,

Lead, Cadmium, Chromium and Manganese. The pH

values were below the DPR specification of 6.5-8.5 and

the pH of the samples worked on were of the range of

5.0-6-0 which is acidic; the low pH could have been as

a consequence of carbon dioxide saturation. The

temperature did not show variations at station 1 and

station 2 but reduced at station 3. The absence of

variation at station 1 and station2 is due to the fact that

water has a great specific heat capacity, the response to

major change in temperature is slow since water bodies

must absorb vast quantities of heat in order to increase

its temperature by 10oC. The implication of high

temperature is that it will reduce the amount of

dissolved air in water which could lead to death of

aquatic organisms. The electrical conductivity reduces

as the effluents move down from station 1 to station 3,

from this study it observed that the sample contain

appreciable amount of dissolved ions thus forming

barrier for survival of organisms. There was no much

significant difference in salinity measured and the

salinity of each station was lower than the DPR

specification, the low level of salinity indicates low

amount of salt content in the sample. Oil and grease

were high at station 1 and station 2 which normally

receive effluent discharged from the company and

station 3, was slightly above the DPR specification of

10. The study has shown high level of oil and grease in

the studied areas.

The value of BOD from all stations was quite

higher than the DPR specification of 10. The BOD test

is useful for determining the relative waste leading to

treatment of plants and the degree of oxygen demand

removal provided by primary treatment, a high BOD

therefore indicates the presence of large amount of

organic pollution caused by microbial organisms in

water and thereby increase the BOD load (Vilia-Elena,

2006). The value of TDS was significantly lower in all

sample stations, it was observed that the TDS value had

a slight difference. The TSS was higher than the TDS in

all stations, station 1 and station 2 had a higher TSS

value and it is above the DPR specification but at

station 3, the TSS value was lower the DPR

specification of 30. The heavy metals present in the

water examined are in much lower concentration and

doesn’t really give a cause of concern like Manganese,

Cadmium and Chromium which were all at the DPR

specification range. Metals like Lead and Cadmium are

highly toxic and harmful to humans and other living

organisms. The level of Lead is quite high in all stations

and it is above the DPR specification, Lead exposure

has been associated with microcytic, hypochromic

anemia with basophilic stippling of erythrocytes

(Emory et al., 1999). Nickel toxicity through

wastewater occurs from Nickel compound itself since

Nickel is not water soluble, exposure to Nickel in

wastewater is less common than airborne exposure, so


17

it’s important to properly treat wastewater to prevent

any underground contamination. Unlike organic

pollutants, metals are not chemically or biologically

biodegradable but may be bioconcentrated in the food

chain. The process of biomagnifications or

bioaccumulation is responsible for pollution indicators,

the concentration of heavy metals in this study were not

high, apart from Lead and Nickel but were at the range

of the maximum allowable limits set by the Federal

Ministry of Environment in Nigeria (FEPA).

CONCLUSION The study revealed that there is need for

improvement on the treatment of effluent by Port

Harcourt Refining Company Ltd. before it is discharged

into the environment. It was found that some physico-

chemical parameters of the effluents been discharged

into the creek is within the limit set by the Federal

Ministry of Environment Nigeria while some of the

parameters determined for the receiving water bodies

from the sample stations is not entirely free from gross

pollution and renders Ekerekana creek water unsuitable

for domestic purposes. This work suggests that there are

other sources of pollution besides refinery effluent that

is responsible for elevated levels of some physico-

chemical parameters in the studied area. This study also

indicates the need for continuous study of surface water

especially in areas where industries are located with

high industrial activities.

REFERENCES 1. Achi, S.S., & Shide, E.G. (2004). Analysis of trace

metals by wet ashing and spectrophotometric

techniques of crude oil samples. J ChemSoc

Nigeria, 29(11), 11-4.

2. Adeniyi, A.A., & Okedeyi, O.O. (2004). Assessing

the speciation pattern of lead and zinc in surface

water collected from Abegede Creek, Ijora, Lagos.

Pak J Sci Indus Res, 47, 430-434.

3. Altindag, A., & Yigit, S. (2005). Assessment of

heavy metal concentrations in the food web of lake

Beysehir, Turkey.Chemosphere, 60, 552-556.

4. American Public Health Association. (2012).

Standard methods for the Examination of water and

wastewater 22nd

Edition.

5. American Standard for Testing Materials. 1997.

6. Awofolu, O.R., Mbolekwa, Z., Mtshemla, V., &

Fatoki, O.S. (2005). Levels of trace metals in water

and sediment from Tyumeriver and its effects on an

irrigated farmland. Water South Africa, 31, 87-94.

7. Chan, H.M., Kim, C., Khoday, K., Receveur, O., &

Kuhnlein, H.V. (1995). Assessment of

dietaryexposure to trace metals in Baffin Inuit

food.Environ Health Perspect, 103, 740-746.

8. Daka, E.R., Moslen, M., Ekeh, C.A., & Ekweozor,

I.K.E. (2007). Sediment quality status of two

creeks in the upper bonny estuary, niger delta, in

relation to urban/industrial activities. Bull Environ

ContamToxicol, 78, 515-521.

9. DWAF. (1996). South Africa water quality

guidelines.Aquatic ecosystem, 1st ed. Department

of Water Affairs and Forestry, 7(1).

10. Egborge, A.B.M. (1995). Water pollution in

Nigeria. Bodiversity and chemistry of Warri

River.Ben Miller Books.Nig Ltd Warri.

11. Ekundayo, (2006). Geoenvironmental properties of

the ground water protective soil layers in Brass,

Nigeria.Int J Environ Waste Manag, 1(1), 75-84.

12. Emory, E., Pattilo, R., Archiobold, E., Bayorn, M.,

& Sung, F. (1999). Neurobehavioral effects of low

level exposure in human neonates. Am J

ObstetGynecol, 181, 2-11.

13. Emoyan, O.O., Ogban, F.E., & Akarah, E. (2005).

Evaluation of Heavy metals loading of River Ijana,

Nigeria.J ApplSci Environ Manag, 10(2), 121-127.

14. Jenkins, P., Southern, T., Truesdale, V., & Jeary,

A. (1996). Waters. In: Watts S, Halliwell L, Eds.

Essential Environmental Science. Methods and

Techniques London: Routledge, 336-350.

15. Lewis, F.H., and Sani, M. (1981). From

Hydrocarbon to Petrochemicals, 1st edition. Gulf

Publishing: Saudi Arabia, 38-47.

16. Nduka, J.K.C., & Orisakwe, O.E. (2007). Heavy

metal levels and physciochemical quality of

portable water supply in Warri nigeria. Annali di

Chem, 97 (9), 867-874.

17. Nduka, J.K.C., & Orisakwe, O.E. (2009). Effects of

effluents from Warri Refinery and Petrochemical

Company (WRPC) on water and soil qualities of

contigious host and impact on communities of

Delta State, Nigeria.The Open Environ.

Pollut.Toxico.Journ, 1, 11-17.

18. Ntuli, F., Kuipa, K.P., & Muzenda, E. (2011).

Designing of sampling programmes for industrial

effluent monitoring.Environ. Sci. Pollut. Res, 18,

479-484.

19. Nwadinigwe, C.A., & Nworgu, O.N. (1999). Metal

contaminants in some Nigerian Wellheads

crudes.Comparative analysis.J ChemSoc Nigeria,

24, 118-121.

20. Nyamangara, J., Bangira, C., Taruvinga, T.,

Masona, C., Nyemba, A., & Ndlovu, (2008).

Effects of sewage and industrial effluent on the

concentration of Zn, Cu, Pd and Cd in water and

sediments along waterfall streams and lower

Mukuvisi river in Harare, Zimbabwe, Physics and

Chemistry of the earth, 33, 708-713.

21. Oberholster, P.J., Botha, A.M., & Cloete, T.E.

(2008). Biological and chemical evaluation of

sewage water pollution in the Rietvlei nature

reserve wetland area, South Africa, Environmental

Pollutin, 156, 184-192.

22. Olajire, A.A., & Imeokparia, F.E. (2000). A study

of the water quality of the Osun River: Metal

monitoring and geochemistry. Bull ChemSoc

Ethiopian, 14(1), 1-8.

23. Olobaniyi, S.B., & Owoyemi, F.B. (2006).

Characterization by factor analysis of the chemical

faciesof ground water in the deltaic plain sands


18

aquifer of Warri, Western Niger-delta, Nigeria. Afr

J Sci Tech, 7(1), 73-81.

24. Rajaram, T., & Das, A. (2008). Water pollution by

industrial effluents in India: Dischrge scenarios and

case of participatory ecosystem specific local

regulation, Futures, 40, 56-59.

25. United States Environmental Protection Agency.

(1986). Quality criteria for water. United States

Environmental Protection Agency Office of Water,

Regulations and Standards: Washington DC,

20460.

26. Vilia-Elena, S. (2006). Parkinson’s disease and

exposure to manganese during welding.Tech J

Welding Allied Process, 2(5), 106-111.

physico-chemical and heavy metal analysis of effluent

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