Scholarly article on topic 'Estimation of Pollution Load of Domestic Sewage to Oued Bechar (SW Algeria) and its Impact on the Microbiological Quality of Groundwater'

Estimation of Pollution Load of Domestic Sewage to Oued Bechar (SW Algeria) and its Impact on the Microbiological Quality of Groundwater Academic research paper on "Chemical sciences"

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{Algeria / "Bechar Oued" / "Urban reject" / "Physicochemical load" / "Microbiological load"}

Abstract of research paper on Chemical sciences, author of scientific article — Badri Abdelkader, Maazouzi Abdelhak, Kabour Abdeslam, Makhloufi Ahmed, Zahraoui Brahim

Abstract In urban areas, population growth generates significant quantities of wastewater that is treated in sewage treatment plants discharged directly or specialize in short uncontrolled water in Bechar Oued. Because of their different origins (domestic waste), these waters are often loaded with organic elements, minerals and microorganisms in which some could be harmful to health and contributes heavily to the degradation of groundwater that may be irreversible. This study was conducted on seven sites rated (R) wastewater localized in Bechar Oued (river), in April 2008, 2009 and 2010. It revealed alarming levels of nitrates, nitrites, nitrogen Kjeldahl (TNK) and ammonium and the presence of chromium and iodine is also detected. Eighteen groundwater samples tested SBi (bacteriological) are showing signs of recent contamination confirmed by the high rate of organisms sought (1400 CFU coliform, fecal coliform CFU 210, D 240 CFU streptococci, Clostridium sulfite reducers 5 CFU).

Academic research paper on topic "Estimation of Pollution Load of Domestic Sewage to Oued Bechar (SW Algeria) and its Impact on the Microbiological Quality of Groundwater"

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Procedía Engineering 33 (2012) 261 - 267

Procedía Engineering

www.elsevier.com/Iocate/procedia

ISWEE'11

Estimation of Pollution Load of Domestic Sewage to Oued Bechar (SW Algeria) and its Impact on the Microbiological Quality of

Groundwater

Badri Abdelkadera*, Maazouzi Abdelhakb, Kabour Abdeslamc, Makhloufi Ahmedd,

Zahraoui Brahime

"LApEHLaboratory, Saad dahleb University Blida 09000,Algeria bWater Science Research Laboratory (LRS-EAU) EL HARACHE Algiers 16000, Algeria cDepartment of Hydraulic, (ENERGARID) Laboratory, Bechar University 08000, Algeria. dDepartment of Biology, Bechar University, Bechar 08000, Algeria. e Department of Process Engineering, (ENERGARID) Laboratory, Bechar University,Bechar 08000, Algeria.

Abstract

In urban areas, population growth generates significant quantities of wastewater that is treated in sewage treatment plants discharged directly or specialize in short uncontrolled water in Bechar Oued. Because of their different origins (domestic waste), these waters are often loaded with organic elements, minerals and microorganisms in which some could be harmful to health and contributes heavily to the degradation of groundwater that may be irreversible.

This study was conducted on seven sites rated (R) wastewater localized in Bechar Oued (river), in April 2008, 2009 and 2010. It revealed alarming levels of nitrates, nitrites, nitrogen Kjeldahl (TNK) and ammonium and the presence of chromium and iodine is also detected. Eighteen groundwater samples tested SBi (bacteriological) are showing signs of recent contamination confirmed by the high rate of organisms sought (1400 CFU coliform, fecal coliform CFU 210, D 240 CFU streptococci, Clostridium sulfite reducers 5 CFU).

© 2012 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of ISWEE' 11

Keywords: Algeria, Bechar Oued, Urban reject, Physicochemical load, Microbiological load;

1. Introduction

The population growth in the town of Bechar generates considerable quantities of sewage discharged into the oued of Bechar which divides the city into two banks of large agglomeration where water resources are heavily used for various activities.

* Corresponding author. Tel.: +213771723076; fax: +21349819024. E-mail address: barimust2000@yahoo.fr.

1877-7058 © 2012 Published by Elsevier Ltd. doi:10.1016/j.proeng.2012.01.1203

Degradation of water quality of the water is caused, firstly, by the nature of the limestone-dominated soil that allows easy infiltration, and secondly by waste liquids. The burden of these releases is increasingly growing with the population development of the town of Bechar. The discharge of this sewage is a source of pollution for agricultural land and wells. The groundwater depth and the distance between wells and pollution source are two important criteria in determining the quality of groundwater. A physicochemical study releases preliminary study showed the possibility of contamination of groundwater by seepage of wastewater [1].

2. Material and methods

The physical parameters are: pH, salinity, TDS and conductivity. The chemical parameters are: calcium, magnesium, sulfate, chloride, nitrate, nitrite, bromine, iodine, zinc, manganese, sodium, potassium, and phosphate, using standard techniques of analysis. Assay methods used are as follows [2]:

• pH, salinity, TDS and conductivity, potentiometric method (Consort 861)

• The nitrogen Kjeldahl after mineralization AFNOR T 90-110 [3]

• The volumetric method : applied to the quantitative analysis of calcium and magnesium. The calcium and magnesium samples were determined by complexometric titration with disodium salt of ethylenediaminetetraacetic acid (EDTA); NFT90-003;

• Nitrates are determined by the potentiometric method (HI 121) with a specific electrode;

• Spectrophotometry was used for the determination of sulfates;

• Colorimetry for the determination of content: Chromium and iodine;

• Flame spectrophotometry to determine the content of sodium and potassium.

2.1. Sampling campaigns

The sampling of rejection was made between April 2008, 2009 and 2010 (Fig.1). Site selection was determined after a preliminary study of the physicochemical parameters, frequency of use by local residents, and according to the direction of the wastewater flow.

Parameters (temperature, conductivity and pH) were measured in situ using a multi-parameter analyzer (Consort 861).

Fig.1. (a) Study site releases; (b) environmental effect

3. Results and discussion

The results of this study are explained in discussing the measured parameters, including in-situ measurements and those performed in the laboratory.

3.1. Estimation of pollution load of domestic sewage to Oued Bechar 3.1.1 Conductivity, TDS (Total Dissolved Salt) and pH

Samples R4 and R6 shown in Fig.2, show the highest conductivities, respectively, 3130 and 4013S/cm. Conductivity increases from south (1899 mS / cm) to the north (4013 mS / cm) [4] denoting the same shape of the dissolved salts carried by these waters, which proves that the samples analyzed are loaded. The wastewater from the Oued Bechar characterized by alkaline gave pH values ranging between 7.57 and 8.13.

Fig.2. Evolution of Conductivity, Salinity and TDS of different samples (Ri)

3.1.2. Calcium and magnesium

The calcium content of wastewater reached a maximum of 201.51 mg/L of Ca2+ for R5 and 165.93 mg/L Mg2+ for R4 north of Oued Bechar. A lower concentration was observed to the south, reaching 122.87 mg/L of Ca2+ and 85.68 mg / L Mg2+. Complexation of these ions with others can explain the evolution from South to North. This decrease appears sufficient to cause the infiltration of wastewater. The solubility of CaCO3 is increased in the presence of proteins and acids, resulting in oxidation of organic matter [5].

Calcium (m g/l) Magnesium (m g /l)

Fig.3. Evolution of Calcium and Magnesium of different samples (Ri)

3.1.3. Nitrate, nitrite, Kjeldahl nitrogen (TNK) and ammonium

Nitrates, nitrites, nitrogen Kjeldahl (TNK) and ammonium concentrations were significant, a maximum of 39.07, 21.06, 20.74 and 17.6 mg / l was observed in (R5, R4, R2 and R1) respectively, see Figure 4. Urine is the main indicator of the presence of nitrogen in urban wastewater and detergents based on ammonium, ammonification reactions can occur that transforms organic nitrogen into ammonium NH4+ (reduced form of nitrogen), because the oxygen demand for ammonia is very high they are molecules (nitrogen compounds) to the origin of fragrant odors[6]. Kjeldahl nitrogen present alarming level.

Fig.4. Evolution of Nitrate, Nitrite, TNK and Ammonium of different samples (Rj)

3.1.4. Sulfate and chloride

Sulfates and chlorides present very high concentrations, a maximum of 658.76 mg/L recorded in R4 and 1236.42 mg/L for R5, respectively. These levels may be probably caused by the use of detergents based on sulfites (metastable state), which transforms this to sulfate (oxidation). A much larger spatial variation observed for chloride, which varies between 767.45 and 1236.42mg/L (Fig. 5). The concentration of chloride undergoes a significant increase from 767.45 to 1236.42 mg/L, this level corresponds to an increasing gradient from south to north.

Fig.5. Evolution of Chloride and Sulfate of different samples (Ri)

3.1.5. Dissolved oxygen

The dissolved oxygen in wastewater (Fig. 6), ranges from small (1 mg O2/L) for R1, to important R3 (5.06 mg O2/L) which may be an indicator of the presence of the organic load is low (organic matter); the degradation of the organic matter by micro-organisms that consume oxygen.

Fig.6. Evolution of dissolved Oxygen of different samples (Ri)

3.1.6. Sodium and Potassium

The sodium content (Fig. 7) moving from north to south to reach a maximum rate of 1630.36 mg/L observed in R1, spatial variation is found for the other samples, this decrease is probably due to adsorption phenomena or imperviousness soil. The high concentration may be toxic to some floras. The analysis results show that the potassium levels ranged from 3.28 mg/l for R3 and 8.48 mg/L for R6 thus having a low spatial evolution.

Fig.7. (a) Evolution of Sodium;(b) evolution of Potassium of different samples (Ri)

3.1.7. Phosphbtes bnd Phosphorus

The levels of phosphate in the waters studied are important, they indicate a fairly large variation from south to north (22.5 to 2 mg/L), but the phosphors show a small change compared to phosphate, the average content of P- PO43-by 50 mg/L is regarded as a signal of eutrophication [7], which can be classified the Oued of Bechar as an euthrophes environments.

Fig.8. Evolution of Phosphates and Phosphorus of different samples (Ri)

3.1.8.Iodine and Chrome

Iodine concentrations Fig. 9 which ranging from 0.26 mg/L for R1 to 1.8 mg/L for R5 thus having a relatively high fluctuation in the sample sets analyzed, share account chromium having a relatively low maximum concentration was observed in R1 with a content of 0.036 mg/L and a minimum of 0.00073 mg/L in R4.

Iodine (mg/l) Chrome(mg/l)

Fig.9. Evolution of Iodine and Chromium of different samples (Ri)

3.1.9. Chemical Oxygen Demand

The Chemical Oxygen Demand (COD) is the amount of oxygen consumed, mg/L, for the chemically oxidizab matter contained in an effluent. It is representative of most organic compounds but also minerals oxidizabl (sulfides, chlorides ,...). The wastewater from the Oued of Bechar has a maximum COD of 150 mg/L.

3.2. Microbiological characteristics of groundwater in the town of Bechar

The microbiological analysis of water allows assessing the risk from pathogenic microorganisms, may be found i waters used by humans, and thereby cause disease, and can also monitor the effectiveness disinfection treatments These pathogens are normal habitat the intestines of man or of some warm-blooded animals. Thus, it has bee proven that water is subjected to pollution by fecal material there is a risk that it contains pathogeni microorganisms from this source [5].

Microbiological analysis indicated that the microbial load is very important Fig. 10 and reveal that there are signs c contamination in the samples where the majority number of organisms sought exceeds the standard (1400 CFU coliforms and fecal coliform CFU 210 Fig.11.

D 240 CFU streptococci Fig.12), except for two sampling (SB9et SB11) where there is no sign of contamination.

1400 1200 1000

£ 800

| 600 | 400 200 0

□ GTaGTC □ GTa20C

[Irin nnrl.-_ri.rlri ri

Fig.10. Representation of germs in ground'

250 200

^ 150 ä

t5 100 c

12 22 CD CD IS) <S>

la(Coliformes) □(Coliformes fecaux) I

Fig.11. Representation of germs in groundwater

300 250 o. 200

- 190

n n n - n n n

cûcûcûcûcûcûcûcûcû

□ (Streptocoques)

Fig.12. Representation of Streptococci in groundwater

4. Conclusion

The results obtained during this study (Analysis of physicochemical and microbiological urban discharges of groundwater) show that the majority of groundwater contamination by sewage in Oued Bechar infiltration process depends on several environmental and climate factors. The treatment of urban wastewater is essential to protect groundwater and the ecosystem.

With maximum levels of 39.07 mg/L nitrate, 20.33 mg/L nitrite, 20.73 mg/L of nitrogen Kjeldahl, 1236.41 mg/L chloride, 658.7 mg/L sulfate 201.5 mg/L of Ca2+ and 165.93 mg/L Mg2+, 1630.36 mg/L of Na+, 8.48 mg/L K+, 22.5 mg/L phosphate, 7.33 mg/L of phosphorus, 1.8 mg/L of iodine, 0.036 mg/L of chromium and low dissolved oxygen levels (1 mg O2/L), wastewater from Bechar Oued prove quite generally carry pollutants and constitute a real threat to the environment of the region, particularly for groundwater.

References

[1] Kabour A, Hani A, Chebbah L. Impact des rejets urbains sur les eaux souterraines dans une région aride cas de la ville de Béchar SW Algérien. GIGE09, Fès, Maroc; 2009.

[2] Rodier .J. L'bnblyse de l'eau.. 8ème éd. Dunod. Paris; 1996.

[3] Norme AFNOR T 90-110 Essais des eaux. Dosage de l'azote de kjeldahl 1981.

[4] Maazouzi A, Badri A, Kettab A, Naceur. M. W, Zahraoui B. Contribution à la caractérisation physicochimique des eaux usées domestique d'Oued Béchar (Algérie). 2éme Congrès International: Gestion Intégrée des Ressources en Eaux et Défis du Développement Durable, Agadir, Maroc. 2010

[5] Hagedorn C, Robinson SL, Filtz JR, Grubbs M, Angier TA, Renaud R.B. Determining sources of fecal pollution in rural Virginia watershed with antibiotic resistance patterns in fecal streptococci. Appl. Environ Microbiol 1999; 65.

[6] Turin A. Lb pollution des eaux souterraines en Lorraine, le cas des nitrates. Thèse Univ. Nancy II, France;1991, 266 p.

[7] Nassali H, Ben Bouih H, Srhiri A. Effect of wastewater on the degradation of water quality in the case of Fouarat lake in Morocco. Proceedings of International Symposium on Environmental Pollution Control and Waste Management, Tunis 7-10 January 2002 (EPCOWM2002), p.3-14.