Impact of Tap Water Conservation in a Clay Jar:
Microbiological and Physicochemical Evaluation after 24 Hours
Bhirich Nihal1,2*, Ghita Salime Meknassi1,2, Ali Cherif Chefchaouni1,2,
Soumaya El Baraka3,4, Brahim Mojemmi1,2
1Department of Analytical Chemistry, Faculty of Medicine and Pharmacy,
Mohammed V University, Rabat, Morocco.
2IBN Sina University Hospital Center, Rabat, Morocco.
3Department of Analytical Chemistry, Faculty of Medicine and Pharmacy,
Cadi Ayyad University, Marrakech, Morocco.
4Mohammed IV University Hospital Center, Marrakech, Morocco.
*Corresponding Author E-mail: bhirich.nihal@gmail.com
ABSTRACT:
Access to clean and uncontaminated drinking water is essential for preventing waterborne diseases, which remain a significant cause of morbidity and mortality, particularly in low-income and developing countries. In regions lacking modern refrigeration or water treatment infrastructure, clay jars are traditionally used for water storage due to their natural cooling properties and partial filtration capabilities. This study aims to evaluate the impact of storing tap water in a clay jar for 24hours, focusing on two primary parameters: microbiological and physicochemical stability. Physicochemical Analysis: Seven physicochemical tests were conducted in accordance with the procedures and sampling conditions outlined by the National Office of Drinking Water (ONEP). The analyses adhered strictly to established protocols to ensure the reliability and reproducibility of results. Microbiological Analysis: The microbiological evaluation was performed using the filter culture method, enabling quantification of bacterial colonies in the water sample. This approach provided insights into the total microbial load and potential contamination. Results support the use of clay jars as a natural and effective way to store drinking water, particularly in domestic or rural environments where access to modern water treatment methods is limited. Conclusion: Storing water in a clay jar has significant benefits for its quality, which supports some of the claims and hypotheses widely shared on social media and websites. The reduction of chloride and sulfates, the stability of pH, as well as the inhibition of microbial growth by cooling and provide a scientific basis for the benefits associated with clay jars for purifying and maintaining the freshness of water.
KEYWORDS: Microbiological stability, Drinking water, Clay jar, Conservation, Quality, Physico-chemical.
INTRODUCTION:
The functioning of the human body requires water, in addition to other organic and inorganic substances. Water is present in large quantities in many tissues. Whenever losses occur due to metabolic reactions, the need for water remains constant to allow for proper recovery1. Water constitutes 50% of body weight, it is essential for physiological homeostasis and cellular processes. It is essential for normal cell growth and multiplication. The body is supplied with water through both drinks and food.
In Morocco, access to drinking water is widespread in urban areas with an individual connection rate of 94% to the network, the rest of the population, located in peripheral neighborhoods in semi-urban areas, is served by standpipes. In rural areas, the rate of access to drinking water has experienced spectacular growth in recent years. Good quality water is characterized by chemical, physical, biological and radiological criteria that comply with local and international standards, such as those of the World Health Organization. The deterioration of this quality can be due to contamination occurring at various stages of the water supply system, particularly during distribution and storage2.
HISTORICAL AND CULTURAL CONTEXT:
Morocco is a country very rich in natural resources: Moroccans have always drunk water directly from the source. Mountainous regions such as the Rif, the Middle or the Great Atlas have the purest water. This water was transported and then preserved in jars made from terracotta, a raw material obtained by cooking clay. In the Moroccan dialect, this jug is called "khabia"3,4.
Drinking water must be pure and free from contamination, as waterborne diseases are a leading cause of morbidity and mortality, particularly in poor and developing countries. It plays a fundamental role in public health, but its quality can be impaired depending on storage conditions5,6 . In many regions where modern refrigeration or water treatment infrastructure is limited, the traditional use of clay jars for water storage remains common. These clay containers are renowned for their thermal properties of natural cooling and partial filtration. However, their ability to preserve the physicochemical and microbiological quality of water, particularly in an urban environment where water is often treated by chlorination, raises questions about possible alterations during storage7,8 .
OBJECTIVE OF THE STUDY:
1. Microbiological stability: Check whether storing water in a clay jar for 24 hours results in microbial proliferation, particularly bacteria or other pathogens, which could compromise the potability of the water.
2. Physicochemical stability: Examine possible changes in the physicochemical parameters of the water (pH, turbidity, temperature, mineral composition, etc.) during 24 hours of storage and determine whether these alterations affect the quality of the water according to consumption standards.
The study seeks to identify whether the use of clay jar for water storage can be considered a safe and effective method or whether health risks exist after prolonged storage.
MATERIALS AND METHODS:
1- Water:
As part of this study, and according to the standards of good sampling practices,9 two samples of 200mL of tap drinking water, from the supply of the city of Rabat, were taken using sterile glass bottles. The first sample was analyzed immediately after sampling (T0), while the second was stored in a sterile glass bottle as a control for 24hours (T). A third sample was taken by pouring 2 L of water from the same tap directly into a clay jar, it is an experimental and partial volume of the total volume of the jar. This sample was subjected to analyses after a storage time of 24hours (T24) in the jar, in order to compare the evolution of the physicochemical and microbiological parameters compared to the control sample. The operation was repeated 3 times for three successive days for the same tap, giving a total of 9 tests.
2- The clay jar:
The clay used for the manufacture of earthenware jars in the Oulja region of Morocco is renowned for its fine texture and high plasticity, facilitating the shaping of the containers. This clay is rich in minerals such as silica, alumina, and metal oxides, which give it increased resistance after firing. Due to its specific composition, Oulja clay allows the production of jars with moderate natural porosity, ideal for the storage of liquids10,11. After purchasing the clay pot, we carried out the same manipulations done at home: rinsing with running water only, the use of laundry soap is not recommended. The ambient temperature for 24 hours was 23C°.
Seven tests were carried out in accordance with the procedures and sampling conditions specified by the National Office for Drinking Water (ONEP). These analyses were carried out in strict compliance with the established protocols to ensure the reliability and reproducibility of the results obtained. The tests are in the form of a KIT which sometimes gives results in the form of an interval of values.
· AQUANAL ® plus Chloride
· AQUANAL ® plus Sulfates
· Microquant ® Ammonium
· AQUAMERCK ® Nitrates
· Lovidond ® Water Testing
· AQUANAL ® plus Iron
· AQUAQUANT ® plus Nitrites
· Microquant ® Phosphate
On the other hand, we carried out other tests such as:
· PH meter
· Bain Marie LB
· Mettler Toledo ® Conductivity Meter
· Thermometer ®
The tests will be applied for the tap water sample at T0, for the control after 24hours and for the sample stored in the jar after 24hours.
The microbiological analysis was carried out by the filter culture method. For each sample, a determined volume of water was filtered through a sterile membrane with a porosity of 0.45µm. The filter was then transferred to a specific culture medium and incubated at the appropriate temperature and for the appropriate time, in accordance with the normative recommendations. This method allows the bacterial colonies present in the water sample to be counted, to determine the total microbial load and identify possible contaminations. No potential microbiological contamination test of the pot itself was carried out.
RESULTS:
The analyses were conducted in accordance with drinking water quality standards, comparing nine samples: three from tap water immediately after sampling (T0), three from water stored for 24hours in a clay jar (T 24h clay), and three control samples stored in a sterile glass bottle for 24hours (T 24h control). The results are shown in Table I.
Table I: Results of the analysis.
|
Setting |
Standard |
T0 |
T24 clay |
||||||
|
Simple 1 |
Simple 2 |
Simple 3 |
Average |
Simple 1 |
Simple 2 |
Simple 3 |
Average |
||
|
Appearance |
Clear, colorless |
Compliant |
Compliant |
Compliant |
Compliant |
Compliant |
Compliant |
Compliant |
Compliant |
|
Chlorides |
≤ 750 mg/L |
600 |
650 |
610 |
620 |
150 |
140 |
160 |
150 |
|
Sulfates |
≤ 200 mg/L |
200 |
200 |
200 |
200 |
150 |
160 |
160 |
156 |
|
Ammonium |
≤ 0.5 mg/L |
0.1 |
0.1 |
0.3 |
0.1 |
0.1 |
0.1 |
0.1 |
0.1 |
|
Nitrates |
≤ 50 mg/L |
5 |
5 |
5 |
5 |
0 |
1 |
0 |
0.3 |
|
Residual chlorine |
≤ 0.3 mg/L |
0.3 |
0.1 |
0.3 |
0.2 |
0.2 |
0.1 |
0.3 |
0.2 |
|
pH |
6.5 - 8.5 at 20-25°C |
7.2 |
7.0 |
7.3 |
7.1 |
7.0 |
7.0 |
7.0 |
7.0 |
|
Conductivity |
110 - 2700 µS/cm at 20°C |
1114 |
1120 |
1118 |
1117 |
1005 |
1000 |
1110 |
1038 |
|
Evaporation residue |
100 - 2000 mg/L |
980 |
1000 |
980 |
986 |
916 |
921 |
912 |
916 |
|
Iron |
≤ 0.3 mg/L |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Nitrites |
≤ 0.1 mg/L |
0.04 |
0 |
0.02 |
0.02 |
0 |
0 |
0 |
0 |
|
Phosphates |
≤ 5 mg/L |
0.2 |
0.2 |
0.2 |
0.2 |
0 |
0 |
0 |
0 |
|
Temperature |
- |
22°C |
18°C |
18°C |
19.3 |
18°C |
16°C |
16°C |
16 |
|
Microbiological analysis |
- |
32 colonies |
30 |
30 |
30 |
26 colonies |
25 |
25 |
25
|
Contineu Table 1
|
Setting |
Standard |
T24 witness |
|||
|
Simple 1 |
Simple 2 |
Simple 3 |
Average |
||
|
Appearance |
Clear, colorless |
Compliant |
Compliant |
Compliant |
Compliant |
|
Chlorides |
≤ 750 mg/L |
600 |
600 |
600 |
600 |
|
Sulfates |
≤ 200 mg/L |
200 |
210 |
200 |
203 |
|
Ammonium |
≤ 0.5 mg/L |
0.1 |
0.1 |
0.2 |
0.1 |
|
Nitrates |
≤ 50 mg/L |
5 |
5 |
5 |
5 |
|
Residual chlorine |
≤ 0.3 mg/L |
0.3 |
0 |
0.2 |
0.2 |
|
pH |
6.5 - 8.5 at 20-25°C |
7.7 |
7.5 |
7.5 |
7.5 |
|
Conductivity |
110 - 2700 µS/cm at 20°C |
1107 |
1110 |
1115 |
1110 |
|
Evaporation residue |
100 - 2000 mg/L |
972 |
980 |
976 |
976 |
|
Iron |
≤ 0.3 mg/L |
0 |
0 |
0 |
0 |
|
Nitrites |
≤ 0.1 mg/L |
0 |
0 |
0 |
0 |
|
Phosphates |
≤ 5 mg/L |
0.4 |
0.2 |
0.2 |
0.2 |
|
Temperature |
- |
23°C |
20°C |
18°C |
20 |
|
Microbiological analysis |
- |
Tablecloth |
32 |
Tablecloth |
Tablecloth |
INTERPRETATION OF RESULTS AND DISCUSSION:
1. Appearance: The water remains compliant (clear and colorless) in all samples (T0, T24 clay jar, and T24 control). No noticeable change in visual appearance, which is a good sign that the clay jar has not altered the appearance of the water.
2. Chlorides (Cl⁻): T0 (620mg/L) vs. T24 clay (150 mg/L): Significant decrease in chlorides after storage in the clay jar, which could be due to adsorption of chloride ions by the porous surface of the clay. T24 control (600mg/L): No significant change in the control sample, indicating that the clay jar played a role in reducing chlorides.
3. Sulfates (SO₄²⁻): T0 (200mg/L) vs T24 clay (156 mg/L): Moderate reduction of sulfates in the sample stored in the clay jar. T24 control (203mg/L): Slight increase in the control, probably due to minor environmental variations.
4. Ammonium (NH₄⁺): No significant change in all samples, ammonium concentrations remain very low (< 0.1mg/L).
5. Nitrates (NO₃⁻): T0 (5mg/L) vs T24 clay (0.3mg/L): Strong reduction of nitrates after storage in the clay jar. T24 control (5 mg/L): No variation in the control.
6. Residual chlorine: T0 (0.2mg/L) vs T24 clay (0.2 mg/L): Residual chlorine in the clay jar remains stable. T24 control (0.2mg/L): Slight decrease but persistent presence in the control.
7. pH: T0 (7.1) vs T24 clay (7.0): pH remains stable in the clay jar, indicating little effect on water acidity or alkalinity. T24 control (7.5): Slight increase in control, possibly due to environmental interactions.
8. Conductivity: T0 (1117µS/cm) vs T24 clay (1038 µS/cm): Slight decrease in conductivity in water stored in the jar, indicating a reduction in dissolved ions. T24 control (1110µS/cm): Stability of conductivity in the control.
9. Evaporation residue: T0 (986mg/L) vs T24 clay (916mg/L): Slight decrease in evaporation residue in the clay jar. T24 control (976mg/L): No notable change in the control.
10. Iron, Nitrites, Phosphates: No notable variation between samples for these parameters, remaining below detection limits or in compliance with standards.
11. Temperature: T0 (22°C) vs T24 clay (19.3°C): The water stored in the clay jar is cooler than in the control (20°C), probably due to evaporation through the porous walls of the jar.
12. Microbiological analysis: T0 (30 colonies) vs T24 clay (25 colonies): Slight reduction in the microbial load in the water stored in the jar. T24 control (water table): Significant proliferation of microorganisms in the control, sign of significant contamination.
These results support the use of clay jars as a natural and effective way to store drinking water, particularly in domestic or rural environments where access to modern water treatment methods is limited. Its porosity contributes to gas exchange and slight evaporation, which can have a cooling effect on the water while influencing its physicochemical and microbiological characteristics.
Storing water in a clay jar for 24 hours has significant effects on several physicochemical and microbiological parameters, providing benefits in terms of quality. The reduction of chlorides is favorable for water quality, as a high concentration of these ions can alter the taste12,13.
Several studies have shown that clay can adsorb certain ions such as chlorides, making it a natural medium for water purification14,15. The clay jar also appears to decrease sulfates, helping to improve water quality by reducing unwanted ions, as observed by Al- Harahsheh and Kingman16,17 in their work on the adsorption of sulfate ions on different media.
The stability of the ammonium concentration shows that the clay jar does not interfere with this parameter, which is essential to maintain the balance of dissolved elements in water18,19. The filtering effect of clay appears to significantly reduce nitrates, a favorable result for human health, since high levels of nitrates can be harmful and are associated with public health risks, as demonstrated in a study20,21. The stability of the pH in the clay jar, which remains within neutral limits, is a positive point that avoids any acid or alkaline imbalance, which is important for safe consumption22,23.
The reduction in conductivity is consistent with the decrease in chloride and sulfate ions, reinforcing the role of clay as a filter medium for some dissolved salts24,25. In addition, the constancy of the levels of residual chlorine, iron, nitrites, and phosphates demonstrates that the water maintains its characteristics within the required standards without compromising health safety, as recommended by the WHO in its drinking water quality guidelines1.
Another advantage of the clay jar is the natural cooling of the water by evaporation, which maintains a lower temperature than the control; this phenomenon is well documented in studies on the natural conservation of water in porous containers26,27,28. Finally, the clay jar seems to inhibit microbial growth, probably due to the antibacterial properties of clay, which is supported in some studies29,30 that show the inhibitory effects of certain clays on microorganisms.
CONCLUSION:
Storing water in a clay jar has significant benefits for its quality, which supports some of the claims and hypotheses widely shared on social media and websites. The reduction of ions, such as chlorides and sulfates, the stability of pH, as well as the inhibition of microbial growth by evaporative cooling provide a lower temperature and provide a scientific basis for the benefits associated with clay jars for purifying and maintaining the freshness of water. However, these positive effects appear to be optimal over a 24-hour storage period. Beyond this period, changes may occur, such as a decrease in residual chlorine, which could reduce the disinfectant effect of the water, or potential microbial proliferation depending on the porosity of the clay and the initial water quality. These limitations must be considered for safe use, especially in contexts where water is stored for longer periods.
CONFLICT OF INTEREST:
The authors have no conflicts of interest regarding this investigation.
REFERENCE:
1. World Health Organization (WHO). Guidelines for drinking-water quality. 4th ed. Incorporating the 1st addendum. Geneva: World Health Organization; 2017. 631 p.
2. Manga M. Ngobi T.G. Okeny L. et al. The effect of household storage tanks/vessels and user practices on the quality of water: a systematic review of literature. Environ Syst Res. 2021; 10(18). https://doi.org/10.1186/s40068-021-00221-9
3. Zhang B. Wang BH. Shen L. Influence of Raw Materials on the Preparation of Terracotta Panel. MSF. 2011; 695: 267–70. https://doi.org/10.4028/www.scientific.net/msf.695.267.
4. Daoudi L. El Boudour El Idrissi H. Saadi L. Albizane A. Bennazha J. Waqif M. et al. Characteristics and ceramic properties of clayey materials from Amezmiz region (Western High Atlas, Morocco). Appl. Clay Sci. 2014; 102: 139-147.
5. Subba Rao J. Suryanarayana Raju D. Vidyadhara S. Venkateswara Rao J. Analysis of Various Components in Water Samples. Asian J. Pharm. Ana. 2018; 8(2): 86-90. doi: 10.5958/2231-5675.2018.00017.0
6. Al-Hiti, M., and Khalaf, A. Physico -Chemical and Microbiological Assessment of Drinking Water Stored in Pottery Vessels in Semi-Arid Regions. Water Science and Technology. 2023; 77(1): 234-243.
7. Gupta S.K. Singh A. Kumar B. Sharma B. Chemical Analysis Case Study of Underground Water in Hapur (West). Asian J. Pharm. Ana. 2017; 7(2): 113-116. doi: 10.5958/2231-5675.2017.00018.7
8. Thakuria M.N. Talukdar A.K. A Study on Physicochemical and Bacteriological Properties of Drinking Water in and around Dhaligaon Area of Chirang District of Assam. Asian J. Research Chem. 2011; 4(1): 91-94.
9. International Standards Organization (ISO). 2008(a). Draft. Water Quality Sampling –Part 6: Guidance on Sampling in Rivers and Streams. ISO 5667-6:2005(E).
10. Boutraa T.Bani-Hani M. “Traditional Pottery in Morocco: A Socio-Cultural and Economic Insight.” Journal of North African Studies. 2011; 16(2): 287-299.
11. Zeroual A. et al. "Physical and chemical characterization of clay raw materials from the Moroccan central Plateau: Application to traditional ceramics." Applied Clay Science. 2008; 42(1-2): 479-485.
12. Zhang Y. Chen J. Liu C. Influence of chloride ions on water taste quality: Mechanisms and implications. Journal of Water Chemistry and Technology. 2020; 42 (4): 340-349. ISSN(P): 2250-1584; ISSN(E): 2278-9383
13. Prashant Kumar. Suman Saurabh. Calibration of QUAL2K water quality model in Pattipul stream (Saran) with Site-specific Parameters. Research Journal of Science and Technology. 2023; 15(2): 105-0. doi: 10.52711/2349-2988.2023.00018
14. Hamad HN, Idrus S. Recent Developments in the Application of Bio-Waste-Derived Adsorbents for the Removal of Methylene Blue from Wastewater: A Review. Polymers (Basel). 2022; 14(4): 783. Published 2022 Feb 17. doi:10.3390/polym14040783
15. Kumar Sanu. Md Jawaid Equabal. Water quality and Catfish (Clarias batrachus) production in selected ponds of Siwan district. Research Journal of Science and Technology. 2023; 15(2): 99-4. doi: 10.52711/2349-2988.2023.00017
16. Tao, X., Xu, N., Xie, M. et al. Progress of the technique of coal microwave desulfurization. Int J Coal Sci Technol. 2014; 1: 113–128. https://doi.org/10.1007/s40789-014-0006-5
17. Dileep Kumar. Braj Bhushan. Prasad Singh. Water Quality Parameters and Ecological status of Eutrophicated Taj Baj Pond Hajipur (Vaishali). Research Journal of Science and Technology. 2023; 15(2): 88-4. doi: 10.52711/2349-2988.2023.00015
18. Li S, Huang G, Kong X, et al. Ammonium removal from groundwater using a zeolite permeable reactive barrier: a pilot-scale demonstration. Water Sci Technol. 2014; 70(9): 1540-1547. doi:10.2166/wst.2014.411
19. Shashank Suman. Prashant Kumar. Water Quality Evaluation in Akilpur lake, Dighwara, Saran of North Bihar. Research Journal of Science and Technology. 2022; 14(1): 47-2. doi: 10.52711/2349-2988.2022.00007
20. Igbinosa, E. O. Okoh A. I. Impact of discharge wastewater effluents on the physico-chemical qualities of a receiving watershed in a typical rural community. Int. J. Environ. Sci. Tech. 2009; 6 (2): 175-182. ISSN: 1735-1472
21. Ashwani Awasthi. Abhishek Dubey. Rajman Singh. Uday Pratap Singh. Shashikant Tripathi. Assessment of Water Quality in Mandakini River at Chitrakoot. Research J. Science and Tech. 2018; 10(3): 223-224. doi: 10.5958/2349-2988.2018.00031.1
22. Grandpré I. FortierD. Stephani E. 2012. Degradation of permafrost beneath a road embankment enhanced by heat advected in groundwater. Canadian Journal of Earth Sciences. 2012; 49(8): 953-962. https://doi.org/10.1139/e2012-018
23. Urmila Barwar D.D. Gudesaria R.P. Mathur. Assessment of Ground Water Quality in some villages of Lachhmangarh Tehsil -Western part, Sikar District, Rajasthan, India. Research J. Science and Tech. 2018; 10(1): 58-67. DOI: 10.5958/2349-2988.2018.00008.6
24. Bhatnagar A. Sillanpaa,M. Utilization of Agro-Industrial and Municipal Waste Materials as Potential Adsorbents for Water Treatment: A Review. Chemical Engineering Journal. 2010; 157, 277-296. http://dx.doi.org/10.1016/j.cej.2010.01.007
25. Ashok Kumar Tiwari. Ground and Drinking Water Quality of Karwi City, Chitrakoot District (U.P.). Research J. Science and Tech. 2015; 7(4): 201-204. doi: 10.5958/2349-2988.2015.00028.5
26. Tahmasebi A. Indigenous knowledge for water management in Iran’s dry land – Siraf. International Journal of Environmental Studies. 2009; 66(3): 317–325. https://doi.org/10.1080/00207230902722481
27. Milan Hait. Shivi Sharma. Leena Sahu. Sangeeta Sharma. Analytical Study of Selected Physicochemical Characteristic of Surface and Underground Water Bodies At Ameri and Its Surrounding Areas. Research J. Science and Tech. 2011; 3(4): 197-199.
28. Mansour O. Habib A. Harfouch R. Analyze Study of Water in Emergency Departments at General Hospitals of the Syrian Coast. Research J. Pharm. and Tech. 2017; 10(1): 01-04. doi: 10.5958/0974-360X.2017.00001.4
29. Bhattacharyya K.G. Gupta S.S. Adsorption of a few heavy metals on natural and modified kaolinite and montmorillonite: A review. Advances in Colloid and Interface Science, 2008; 140 (2): 114-131. ISSN 0001-8686, https://doi.org/10.1016/j.cis.2007.12.008.
30. Natarajan S. Sukanya Devi R. Surya R. Development of Eco-friendly water repellent fabrics. Research J. Engineering and Tech. 2017; 8(4): 389-392. doi: 10.5958/2321-581X.2017.00069.1
|
Received on 05.11.2024 Revised on 15.03.2025 Accepted on 21.05.2025 Published on 05.09.2025 Available online from September 08, 2025 Research J. Pharmacy and Technology. 2025;18(9):4358-4362. DOI: 10.52711/0974-360X.2025.00624 © RJPT All right reserved
|
|
|
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Creative Commons License. |
|