Bio-Purification of River Kaduna Water Using Moringa Oleifera Seed Powder

: The study was designed to investigate the effect of Moringa Oleifera seed powder in purifying raw water. Water samples were collected in plastic bottles on monthly basis, for six months in the dry and wet season along the Southern axis of river Kaduna (Kakuri). Physicochemical parameters of the water such as Turbidity, DO/BOD, Hardness, pH and Electrical Conductivity were carried out using Standard Methods. Heavy metals of the water such as Copper, Arsenic, Chromium and Lead were analyzed using Atomic Absorption Spectrophotometer. The effect of various concentrations of the seed powder on physicochemical parameters and heavy metals of the water were determined using jar test in the dry and wet seasons. The result of the physicochemical parameters such as turbidity (278.00±38.62 FAU), BOD (204.73±111.63 mg/L), E.C (2195±107.39 µmhos/cm ) in the wet season indicated a high level of pollution in the water while in the dry season, low levels of turbidity (35.00±6.43FAU), BOD (0.53±0.13mg/L), and E.C (89.33±14.73µmhos/cm) showed a low level of pollution. The pH of the water in both seasons was neutral (7.07±0.64 and 7.94±0.59) and within the WHO limits of 6.5-8.5. The result of heavy metals in the dry season; Cu (0.015±0.001), As (0.793±0.001) and wet season, Cr (0.019±0.001) and Pb (0.084±0.001). The result obtained revealed that the extract has high potential to reduce turbidity, improve low DO’s, reduce high BOD’s in the water, with high antimicrobial properties that can be used in reducing bacteria load.


INTRODUCTION
Water purification is the removal of contaminants such as parasites (Giardia, Cryptosporidium), bacteria, algae, viruses, fungi, minerals (including toxic metals such as Lead, Copper, Chromium, Arsenic, Iron etc.) from pure water, to produce water that is safe for human consumption and for other industrial purposes.The main aim of purifying water is to produce water that is safe for drinking as well as for other domestic needs.Most water sources are treated for human consumption, domestic and industrial uses.However, water may also be purified for different purposes such as fulfilling the requirements of medicine, pharmacology, chemistry and environmental applications.
The use of plant materials to purify water has been in use for over a hundred years and most of the plants that have been tested over the years, seed powder of Moringa oleifera Lam was found to be an effective primary coagulant for water treatment that is similar to alum [1].Previous reports have shown that Moringa seed powder has antimicrobial properties, it is non-poisonous and non-synthetic.Thus, its use in bio-purification of water is recommended in developing nations [2].

Moringa oleifera
Moringa oleifera is a native of India grown widely throughout the tropics.It is also known as "horse radish" tree.It ranges in height from 5-12m with an open, umbrella-shaped crown, straight trunk and corky, whitish bark with tuberous tap root.The ever green foliage (depending on climate) has leaflets of about 1-2cm in diameter, with white cream colored flowers.The fruits (pods) are initially light green, slim and tender, eventually becoming dark green, firm and tip to 120cm long, depending on the variety.
Fully matured, dried seeds are round or triangular, with the kernel surrounded by a lightly, wooded shell with three papery wings [3].

Kingdom Plantae
Sub-kingdom Tracheobionta

Super division Spermatophyta Division Magnoliophyta
Class Magnoliopsida

Purification Ability of Moringa oleifera
Moringa oleifera seeds treat water on two levels by acting both as a coagulant and an antimicrobial agent.It is generally accepted that Moringa works as a coagulant due to its positively charged watersoluble proteins which bind with negatively charged particles (silt, clay, bacteria, toxins, etc.) allowing the resulting "flocks" to settle to the bottom or be removed by filtration.The antimicrobial property of Moringa is however, under investigation.
Findings support recombinant proteins both removing microorganisms by coagulation as well as acting directly as growth inhibitors of the microorganisms.While there is ongoing research being conducted on the nature and characteristics of these components, it is accepted that treatments with Moringa solutions will remove 90-99.9% of the impurities in water [4].

Coagulation Properties of Moringa oleifera
The seed kernels contain high quantities of a series of low molecular weight water soluble proteins which in solution, carry an overall positive charge.The proteins act similarly to synthetic, positively charged polymer coagulants.When added to raw water, the proteins bind to the predominant negatively charged particulates that cause turbidity (raw water, silt, clay, bacteria etc.).
Under frequent agitation these bound particulates increase in size and form flocs, which may be left to settle by gravity or be removed by filtration.The seed is rich in copper which acts as a Coagulant in raw water and waste water treatment [3].

Comparison between the Mechanism of Water Purification of Alum powder and Moringa oleifera Seed Powder
Alum, also known as Potassium Aluminium Sulphate has been in water purification for a very long time.Environmental Science Activities for the 21 st Century Project, stated that purifying water is very important as it produces water that is free of pathogens and fit for drinking.Novak and Watts (2005) [5], pointed out phosphorus as a common contaminant present in water sheds where there has been an accumulation of excess phosphorus in the soil where animal production is practiced and is linked to the increasing concentrations of dissolved Phosphorus in rivers and streams.
Alum in its powdered form when added in a vessel of water, is stirred using a stirring stick for a few minutes (5minutes at least) and sedimentation takes place as the phosphorus particles in the water bind with the powdered alum forming flocs.The water is filtered using a filter apparatus that traps the phosphorus and alum mixture while allowing the water to pass through.Although Alum purifies water of its phosphorus content, the water may still be unsafe for drinking and for other domestic uses until it is sterilized by adding a microbe killing agent to the purified water to disinfect and make it safe for human consumption [5].
Whereas, Moringa oleifera seed powder when used in water purification acts as a coagulant and an antimicrobial agent (disinfectant).The water-soluble proteins with positive charges present in the M.oleifera seed bind with the negatively charged particles allowing the resultant "flocs" to settle to at the bottom [4].The phytochemical composition of the Moringa oleifera seed powder such as Flavonoids, Saponins, Steroids, Tannins and Terpenoids are responsible for the antibacterial activity of the seeds on pathogenic organisms in water [6].Tannins have been reported to prevent the development of micro-organisms by precipitating microbial protein and making nutritional protein unavailable for them [7].

Figure 1a. Map of the study area Figure 1b. Study area with sampling points
The study was carried out in selected locations within Kakuri and Sabon-tasha, southern areas of Kaduna State, with sampling points properly labelled and demarcated in the maps above.University for identification.Samples were collected in duplicate from the Southern axis of river Kaduna, for physicochemical parameters/Heavy metal analysis in plastic bottles with screw caps and taken to the laboratory in an ice chest for analysis as used by Zakky et al., (2016) [8].

Water Sampling within the Study Areas
Moringa oleifera seeds were air-dried on a non-absorbent tray for a week and peeled to obtain nuts.The dried nuts were milled to a fine powder and sieved to a mesh size of 150µm to obtain the seed powder.

PHYSICOCHEMICAL PARAMETERS ANALYSIS Turbidity Determination
Using the Absoptometric Method, a colorimeter with model number DR/890, (Sherwood, USA) was switched on and the stored program number for turbidity 0-1000 FAU "Formazin Attenuation Units" was displayed on the colorimeter.A sample cell was filled with 10ml deionized water and placed into the cell holder and tightly covered with an instrument cap to serve as blank (so as to zero the meter to 0 FAU).After which raw water samples from the southern axis of river Kaduna were thoroughly mixed.
Using a pipette, 10ml was transferred into another sample cell tightly covered with the instrument cap and placed in a cell holder on the colorimeter and the results were taken in FAU.The same procedure was used to determine the turbidity of the treated water samples dosed with varying concentrations of Moringa oleifera seed powder from 0.5-180mg/l in the dry season and 200-1000mg/l in the wet season.

BOD and DO Determination
The BOD and DO of the water sample collected from the Southern axis of river Kaduna were tested on the same day the samples were collected (both the untreated and the treated water samples) with varying doses of the Moringa oleifera seed powder ranging from 0.5mg/l-180mg/l in the dry season and 200-1000mg/l in the wet season.The samples were initially used to rinse the BOD/DO bottles made by Kimax Company, England were filled up with 300mls of the water, ensuring no air bubble remained in the bottle.
Two (2) ml of alkali-iodide-acid reagent was also added.The bottle was capped and shaken vigorously.As a result of this; it formed a brownish to whitish precipitate, which was also allowed to settle then made up to 100ml.Two (2) ml sulphuric acid (H2SO4) was also added into the bottles.Two hundred (200) m1 of the sample (treated water) were measured into a conical flask and titrated with sodium thiosulphate (0.025N) until a pale yellow colour was formed, titration continued until the sample became colourless.
The volume of the sodium thiosulphate used for titration was noted.At this point; D.O was estimated as 1ml of sodium thiosulphate = 1mg per liter of DO.After the test of the first day the BOD bottles were rinsed again and filled with the sample.The samples were then incubated for five (5) days in an incubator at 20°C.On the fifth day, the same DO test was carried out as DO5 and the BOD is calculated as follows: BOD Difference between DO1 on the first day, and DO5 after 5 days.

Determination of Optimum Dosage Using Jar Test Machine
Jar test was carried out at the Department of Water Resources and Environmental Engineering, Ahmadu Bello University, Zaria, Kaduna State.Jar testing was carried out by the method described by APHA (2005) using a Novatech Jar Testing Machine with Model number F105A0111, FC4S made in USA.Preparation of stock solution was done by weighing one gramme (1g) of the seed powder of Moringa oleifera and transferring same quantitatively into a 1000ml flask, made up to 100ml with distill water and shaken vigorously for 10-15mins.
This procedure was carried out on monthly basis, in six months (each sample was tested three times to obtain the mean) and grouped in Batches "A, B, C, D, and E" with variations in the gramme of Moringa oleifera seed powder measured for the preparation of the stock solution for each batch as shown below; Batch A-one gramme(1g) M.O powder in 100ml distill water for concentrations 0.

Statistical Data Analysis and Experimental Design
All data collected from this study were subjected to the analysis of variance (ANOVA) using the general linear model of Statistical Analysis System (SAS, 2001) to analyze the differences among group means in the treated sample.Significant differences among means were separated using the Duncan multiple range test [14] in the SAS package.The experimental design for the treatment was a Complete Randomized Design (CRD), replicated three times.The layout (CRD) of the experiment is shown below:  The result of some physicochemical parameters of water from the Southern axis of river Kaduna in the dry and wet season showed low turbidity levels in the dry season (35.00±6.43FAU)and high levels of turbidity in the wet season (278.00±38.62FAU).

Dry
The DO levels in the dry and wet season ranged from 1.97±0.12 to 2.10 ± 0.1,BOD levels in the dry season were lower(0.53±0.13)than the wet season which were extremely high(204.73±111.63).The amount of hardness in the water was higher in the dry season than in the wet season with mean values ranging from 80.84±10.06 to 128.33±25.85.pH mean values of the water in the dry and wet season were in the range of 7.07±0.64and 7.94±0.59while the Electrical Conductivity(E.C) of the water was lower in the dry season(89.33±14.71)andsignificantly high in the wet season(2195±107.39µmhos/cm).The result in table 2 shows the presence of some heavy metals such as Copper, Arsenic, Chromium and Lead in the water from river Kaduna at higher concentrations in the dry and wet season.The concentrations of Copper in the dry and wet season ranged from 0.015±0.001to 0.012±0.001and the concentrations of Arsenic in the dry and wet seasons were from 0.793±0.001to 0.062±0.001.While the concentrations of Chromium in the dry and wet season ranged from 0.012± 0.001 to 0.019 ±0.001 and the concentrations of Lead in both seasons were from 0.068±0.001to 0.084±0.001respectively.

DISCUSSION
The result of the physicochemical parameters of water from the Southern axis of river Kaduna in the dry and wet season showed low turbidity levels in the dry season (35.00±6.43FAU)and high levels of turbidity in the wet season (278.00±38.62FAU), although the turbidity levels in the dry season were low, they were above the WHO limits of 5.0 FAU.
This observation is similar to that of Ogbozie et al. [9], who recorded high turbidity values in the dry season ranging from 0.6-26.8FAUand 28.9-196.4FAU in the wet season at different sampling points of the river Kaduna.The high turbidity values in the wet season, may be due to a high amount of suspended particles and organic matter in the water.The DO levels in the dry and wet season were low (1.97±0.12 to 2.10 ± 0.1) and below the WHO limits of 4.0 mg/l.The low DO levels in the water indicates that the water is polluted and the rate of pollution was more in the dry season as seen in the extremely low DO levels recorded.
This may be due to the inflow of phosphorus and nitrogen from farming and industrial activities into the river that enhance the growth of algae and phytoplankton.According to the classifications of McGowan [10], the water samples in the dry and wet season were moderately hard.pH mean values of the water in the dry and wet season(7.07±0.64 to 7.94±0.59 ) were all within the WHO limits of 6.5-8.5 and similar to the reports of Yusuf, Durojaye and Salawudeen [11], who reported pH values for all the sampling points of the river Kaduna between 7.23-8.32for the wet season and 6.9-10.1 for the dry season with the highest pH value of l0.l at the Nasarawa Bridge sample where effluent from the activities of textile, food and beverage industries are introduced into the Kaduna River.
The low Electrical Conductivity(E.C) of the water in the dry season (89.33±14.71)and significantly high E.C in the wet season(2195±107.39µmhos/cm)observed in the river during the wet season are a measure concern because rain water has low conductivity and the addition of rain water in rivers lowers the conductivity of the river but the reverse was the case in the reports on the study carried out on the southern axis of river Kaduna which may be an indication that the river may be highly polluted.
This report is similar to the reports of Ogbozige et al. [9], who also reported slightly low conductivity values in the dry season ranging from 88-915µmhos/cm and 87-890µmhos/cm in the wet season at different sampling points.
The result in table 2 shows the presence of some heavy metals such as Arsenic, Chromium and Lead in the water from river Kaduna in concentrations higher than the WHO permissible limits in the dry and wet season except for the concentrations of Copper in the dry and wet season (0.015±0.001 and 0.012±0.001)that were below the WHO limits of 2.0mg/l.This observation is supported by Abui et al. [12], who also reported higher concentrations of Copper, Arsenic, Chromium and Lead in both the dry and wet season at the southern part of river Kaduna(Kakuri)were all above the WHO limits of 2.0mg/l for Copper,0.01mg/lfor Arsenic,0.05mg/lfor Chromium and 0.01mg/l for Lead.The high concentrations of Arsenic, Chromium and Lead in the dry and wet seasons could be as a result of the activities of industries that manufacture batteries, paint, petroleum refining and spillage that are located in the southern parts of the river Kaduna [12].
This also means that the river is adversely polluted during both seasons but the rate of pollution is less during the wet season due to the heavy rains, as the concentrations of some of the metals such as Copper and Arsenic were lower in the wet season.High concentrations of Arsenic, Chromium and Lead in the river are a source of concern as aquatic lives and aerobic conditions may be affected.This observation is similar to the findings of Abubakar et al. [13],who reported high concentrations of some heavy metals in the surface waters of the river Kaduna from point A (Kakuri -Makera drain) such as; Chromium (3.72mg/l), Arsenic (2.59mg/l), Iron (5.20mg/l), Copper (3.16mg/l), Lead (3.67mg/l) which were all above the WHO limits of 0.05mg/l for Chromium,0.01mg/l for Arsenic,0.3mg/lfor Fe,2.0mg/l for Copper, and 0.01mg/l for Lead, except for Zinc(2.32mg/l)which were within the WHO limits of 5.0mg/l.

CONCLUSION
Moringa oleifera seed powder had significant effect on some of the physicochemical parameters tested.In the dry season, treatment with concentrations 165.5mg/l achieved 56.2% turbidity removal, 18.3% DO and 79.2% BOD improvement.While in the wet season, concentrations 300.5mg/l achieved 93.6% reduction in BOD.Treatment with Moringa seed concentrations (900.5mg/l)improved DO by 21.9% and reduced E.C by 88.0%.Comparatively, it can be said that M. oleifera was more effective in the dry season than in the wet season.

Sampling point- 1 : 2 :
Along Nigerian Breweries Sampling point-Around Romi/Abuja junction Sampling point-3: Around Kaduna textile Sampling point-4: Control (Upstream reach of Kaduna River along Southern Kaduna Axis) Material (Moringa oleifera) Collection and Preparation Moringa oleifera seed pods were purchased from Kasuwan Barchi, Tudun Wada market in Kaduna State and taken to the Herbarium unit of the Department of Biological Sciences Kaduna State Therefore, BOD = (DO1 -DO5) x volume of BOD Bottle.(ml of samples used)Determination of the presence of Some Heavy Metals of Water from River Kaduna and the effects of Moringa oleifera Seed Powder Concentrations on the Heavy MetalsThe presence of some heavy metals such as Copper, Arsenic, Lead and Chromium in the water were determined using a Buck Scientific 210 Atomic Absorption Spectrophotometer (AAS) made by Agilent Technology, USA using air-acetylene flame at various wavelength for each of the heavy metals in the dry and wet seasons as described by the Standard Methods of Association of Official Analytical Chemistry (AOAC,1990).The effect of various concentrations of Moringa oleifera seed powder on the heavy metals present of after treatment with varying concentrations of Moringa ranging from, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 10.0, 20, 30, 40, 50, 60, 70, 80, 90, 100, 120, 130, 140, 150, 160, 170 and 180mg/l in the dry season and 200-1000mg/l in the wet season.

5 - 5 .
0mg/l, B-2g M.O powder in 100ml distill water for concentrations 5.5-10mg/l, C-10g M.O powder in 550ml distill water for concentrations 20-100mg/l, D-50g M.O powder in 1200ml for concentrations 110-180mg/l, E-150g M.O powder in 5400ml distill water for concentrations 200-1000mg/l.A total of one hundred and fourteen (114) clean beakers labelled with the various concentrations (0.5-5.5 and up to180mg/L) in the dry season and twenty-seven (27) clean beakers labelled with the concentrations 200-1000mg/L (including that of the untreated water) in the wet season were placed on a working bench.A measure of one (1) litre of untreated water was transferred into the beakers labelled with various concentrations of Moringa.A dose of 0.5-5.5up to 180mg/L of the stock solution during the dry season and a dose of 200-1000mg/L during the wet season were measured and transferred into the beakers respectively.
Individual observation, µ is the overall mean i α is the treatment effect eijk is the experimental errorRESULT AND DISCUSSION

Table 1 . Physicochemical Parameters of Water sample from the Southern Axis of River Kaduna in the Dry and Wet Season
All values in each table are expressed as Mean ± SE (Standard Error).DO -Dissolve Oxygen, BOD -Biochemical Oxygen Demand, E.C-Electrical Conductivity; Mg/L-Milligram per Liter, FAU-Formazin Attenuation Units, WHO-World Health Organization.

Table 2 . Heavy Metals of Water from the Southern Axis of River Kaduna in the Dry and Wet Season
Note: All values in each table are expressed as Mean ± SE (Standard Error).