Bulletin de la Société Royale des Sciences de Liège
Surface waters are usually exposed to industrial, urban, and agricultural wastes. This study asse... more Surface waters are usually exposed to industrial, urban, and agricultural wastes. This study assessed the water and the sediments quality of the important primary watercourse in Tunisia and the principal source of domestic and irrigation purposes, the Medjerda River. Water samples were analyzed for total suspended solids, calcium, magnesium, total hardness, carbonates, bicarbonates, residual sodium hazard, and magnesium hazard. They were collected from five sampling sites along the Medjerda watercourse from upstream to downstream through two campaigns, one at the end of the moist period and the other at the half of the dry one in line with irrigation. The presence of high concentrations of (i) magnesium, which varied from 25.51 to 61.65 mg l-1 for the moist period and from 27.58 to 133.10 mg l-1 for the dry one; (ii) carbonates that varied from 18.0 mg l-1for the two campaigns to respectively 49.8 and 66.0 mg l-1 for the humid and the dry periods and (iii) total hardness that varied...
Advances in Science, Technology & Innovation, 2018
In recent decades, a pressure on water resources has increased at a same time of demand increase ... more In recent decades, a pressure on water resources has increased at a same time of demand increase in the world and particularly in Tunisia.
The present study aims the assessment of surface water and sediment qualities of the transboundar... more The present study aims the assessment of surface water and sediment qualities of the transboundary Medjerda River and its tributaries, influenced by industrial, urban, and agricultural wastes. Surface water samples, taken from five control points during humid and dry periods, were analyzed for physico-chemical, heavy metals, by atomic absorption, and bacteriological parameters (most probable number technique (MPN)). The highest values obtained respectively during the humid and the dry periods were 8.08 and 8.05 for pH; 5300 and 6440 μS cm-1 for conductivity; 1320 and 1325.21 mg L-1 for chloride; 3.22 and 4.37 mg L-1 for nitrates; 4240 and 5152 mg L-1 for total dissolved solids; 7.1.104 and 5.18.106 MPN /100 ml for fecal coliforms; 3.82.104 and 7.59.105 MPN/100 ml for Escherichia coli; and 6.99.102 and 9.25.106 MPN/100 ml for fecal streptococci. In parallel, sediments were assessed (n=4) for metallic and bacteriological contamination. Results of the calculation of the geo-accumulation index, enrichment factor, ecological risk, and risk index depicted severe metal contamination mainly by lead and cadmium, particularly in the Kasseb tributary. Anthropogenic activities are the main origins of metal pollution. The study also proves that the Medjerda ecosystem suffers from severe bacteriological contamination, expressed in MPN per Dry Matter (DM) (4.26 108 MPN g-1 of DM for fecal coliforms and 4.57 108 MPN g-1 of DM for fecal streptococci). Two water quality indexes (CCME-WQI and AWQI) were used, for the first time, to ascertain the overall quality and the suitability of the Medjerda River water for drinking. Both argued on its poor and unsuitable quality. The extent of the assessed pollution implies that the situation is frightening to the biota and its users. Regular quality assessment of this ecosystem is compulsory to control its pollution and to guarantee human health safety.
International Journal of Environmental Research and Public Health, 2022
Wastewater sludge represents an important resource for reuse in agriculture. However, potentially... more Wastewater sludge represents an important resource for reuse in agriculture. However, potentially harmful pathogens are a main threat in this context. Thus, the aim of this study was to examine the presence of helminth ova and protozoan cysts in dried sewage sludge samples collected from ten wastewater treatment plants (WWTPs) located in eight governorates in Tunisia. Based on morphological criteria, protozoan cysts of Giardia spp., Entamoeba histolytica/dispar/moshkovskii, and Entamoeba coli, were detected in all dried sludge composite samples (N = 116) from the investigated WWTPs. The mean concentration ranged from 1.4 to 10.7 cysts per 100 g dry matter (DM). The identified helminth eggs were Ascaris spp., Strongyles, Taeniid eggs, Hymenolepis nana, Enterobius vermicularis, and hookworm species. Ascaris spp. and Taeniid eggs were detected in 56.9 and 74.1% of analyzed samples, respectively. The presence of Trichuris spp., Hymenolepis diminuta, and Toxocara spp. eggs in dried sewag...
Une etude parasitologique a ete realisee sur des echantillons d’eaux usees et de boues residuaire... more Une etude parasitologique a ete realisee sur des echantillons d’eaux usees et de boues residuaires collectes a partir de sept stations d’epuration situees en Tunisie entre les mois de septembre et de decembre 2005. Parmi les 28 echantillons etudies, 100 % sont retrouves positifs avec une predominance constante des kystes de protozoaires sur les œufs d’helminthes. Les resultats obtenus ont permis d’evaluer la technique de detection adoptee (technique de Bailenger) et l’efficacite relative du procede de traitement (boues activees et lagunage). Tous les echantillons d’eaux usees brutes contiennent des kystes d’Entamoeba coli, d’Entamoeba histolytica/dispar et des kystes de Giardia sp. Au cours du traitement, la totalite des œufs et la majorite des kystes sont eliminees. Dans les echantillons d’eaux usees traitees, les rendements epuratoires sont donc de 100 % pour les œufs d’helminthes et compris entre 82 et 100 % pour les kystes de protozoaires suivant la filiere de traitement et le m...
Water and Sanitation for the 21st Century: Health and Microbiological Aspects of Excreta and Wastewater Management (Global Water Pathogen Project), 2019
Private cisterns or underground tanks may be at risk for certain types of contamination associate... more Private cisterns or underground tanks may be at risk for certain types of contamination associated with adverse health effects. This first and preliminary study evaluated the parasitological quality of drinking water stored in home-based cisterns in rural areas in seven delegations of the Kairouan Governorate in the center of Tunisia. The practices of water management and hygiene were also surveyed in addition to details related to the age and the kind of material used to make these home-based tanks. To achieve this purpose, 39 samples from five different sources—(i) rain water, (ii) truck cisterns, (iii) a mix of these two, (iv) wells, and (v) stored tap water—were collected and examined for the presence of parasites using the Bailenger modified technique. Microscopic/morphological analysis showed the presence of three gastrointestinal protozoa: Giardia duodenalis (10–380 cysts/L), Entamoeba histolytica/dispar/moshkovskii (30–400 cysts/L), and Entamoeba coli (20–200 cysts/L). These...
Le processus de photosensibilisation (phototraitement) de l'eau suscite beaucoup d'intérê... more Le processus de photosensibilisation (phototraitement) de l'eau suscite beaucoup d'intérêt, car il implique trois composants qui sont individuellement inoffensifs pour le milieu biologique, à savoir le photosensibilisant, la lumière et l'oxygène moléculaire. La photostabilité de la porphyrine tétra-méso-cationique (T4MPyP) dans l'eau usée et l’efficacité du phototraitement dépend de la concentration du photosensibilisant, de la qualité de l'eau (contaminants organiques, turbidité, pH, taux d'oxygène dissous et épaisseur de la lame d'eau) ainsi que de l'intensité et de la nature du rayonnement lumineux. L’étude expérimentale consistait à apporter à un sol sableux i) de l’eau usée secondaire traitée par boues activées, ii) la même eau usée, mais phototraitée avec 5 μM∙L-1 de T4MPyP pendant 6 h d’ensoleillement, et iii) une eau de puits. L’eau usée phototraitée était conforme aux normes tunisiennes (NT 106.03) pour l’irrigation sans restriction au niveau...
Limited access to safe water enhances poverty, hunger and diseases. This study evaluated the drin... more Limited access to safe water enhances poverty, hunger and diseases. This study evaluated the drinking water quality stored in home-based systems, located in rural areas of Tunisia. Water management was also documented as an improvement of good practice as most of the water contamination could be related to behavioral patterns. Thirty-nine water samples from five different sources (rainwater, truck cistern, mix, etc.) were screened for enteric parasitic contamination with the modified Bailenger technique. This technique allowed the detection of three protozoa: Giardia spp.; Entamoeba histolytica/dispar/moshkovskii; Entamoeba coli and one helminth specie: Ascaris spp. The overall prevalence of these intestinal parasites was approximately 97% with a relatively high frequency of protozoa over helminths and more specifically E. histolytica/dispar/moshkovskii. This incidence could be correlated to the lack of hygiene practices, sanitation and education. This situation requires the need fo...
The present study aimed to: (i) identify helminth eggs and protozoan cysts in wastewater samples ... more The present study aimed to: (i) identify helminth eggs and protozoan cysts in wastewater samples to which both human and animals could be exposed when they are reused in agriculture; and (ii) evaluate the efficiency of their removal by two wastewater treatment systems (activated sludge and lagoon). For these purposes, 234 wastewater samples (117 raw, 117 treated) were collected from 20 wastewater treatment plants (WWTPs) in Tunisia over a one-year sampling period. Parasitic load was enumerated by the modified Bailenger method. The results showed that helminth eggs found were Nematodes mainly represented by Ascaris sp. (95%), Hookworm species (50%), and Enterobius vermicularis (45%). For Cestodes, species identified were Taeniid eggs (85%), Hymenolepis nana (70%), Hymenolepis diminuta (55%) and digestive Strongyles. Among protozoa, Giardia sp., Entamoeba histolytica/dispar/moshkovskii and Entamoeba coli cysts were found in 100% of raw wastewater samples. The overall removal efficienc...
Helminth eggs and protozoan cysts were enumerated in raw and treated wastewater in Tunisia in ord... more Helminth eggs and protozoan cysts were enumerated in raw and treated wastewater in Tunisia in order to determine their removal by wastewater treatment and to provide quantitative data for developing regulations for wastewater quality that are currently lacking. Raw and treated wastewater samples were collected from 17 plants in Tunisia during 2006-2007 and analyzed for parasites using the modified Bailenger method. Two groups of parasites, namely, Ascaris sp., Entamoeba coli, Enterobius vermicularis, and Taenia sp. (group 1) and Entamoeba histolytica/dispar, Giardia sp., and Taenia sp. (group 2) could statistically be distinguished according to their removal by wastewater treatment. Group 1 parasites were removed by 1.1 log(10) (92.4%) and group 2 parasites by 0.61 log(10) (76%). The ubiquitous presence of parasitic protozoa in Tunisian wastewater and ineffective wastewater treatment lead to their proliferation in surface waters with a high probability of exposure of human and animals to these parasites and consequent adverse health effects, as is apparent from epidemiologic data as well. This study provides a quantitative basis for risk assessment studies and development of mitigation strategies, such as improving wastewater treatment efficiency.
The aim of this study was to evaluate the photobactericidal effect of four photosensitizers (PSs)... more The aim of this study was to evaluate the photobactericidal effect of four photosensitizers (PSs) with different structural and physico-photochemical properties, namely mesotetracationic porphyrin (T4MPyP), dianionic rose Bengal (RB), monocationic methylene blue (MB) and neutral red (NR). Their photokilling activity was tested in vitro on pathogenic bacteria such as Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) suspended in nutrient broth (NB) and in phosphate buffered saline (PBS) through following their influence on the PSs antimicrobial efficacy. Photodynamic inactivation (PDI) experiments were performed using visible light (L) and different PSs concentrations (20–70 μM). The ability of these PSs to mediate bacterial photodynamic inactivation was investigated as a function of type of PS and its concentrations, spectral and physico-chemical properties, bacterial strain, irradiation time and suspending medium. Indeed, they showed antibacterial effects...
Bulletin de la Société Royale des Sciences de Liège
Surface waters are usually exposed to industrial, urban, and agricultural wastes. This study asse... more Surface waters are usually exposed to industrial, urban, and agricultural wastes. This study assessed the water and the sediments quality of the important primary watercourse in Tunisia and the principal source of domestic and irrigation purposes, the Medjerda River. Water samples were analyzed for total suspended solids, calcium, magnesium, total hardness, carbonates, bicarbonates, residual sodium hazard, and magnesium hazard. They were collected from five sampling sites along the Medjerda watercourse from upstream to downstream through two campaigns, one at the end of the moist period and the other at the half of the dry one in line with irrigation. The presence of high concentrations of (i) magnesium, which varied from 25.51 to 61.65 mg l-1 for the moist period and from 27.58 to 133.10 mg l-1 for the dry one; (ii) carbonates that varied from 18.0 mg l-1for the two campaigns to respectively 49.8 and 66.0 mg l-1 for the humid and the dry periods and (iii) total hardness that varied...
Advances in Science, Technology & Innovation, 2018
In recent decades, a pressure on water resources has increased at a same time of demand increase ... more In recent decades, a pressure on water resources has increased at a same time of demand increase in the world and particularly in Tunisia.
The present study aims the assessment of surface water and sediment qualities of the transboundar... more The present study aims the assessment of surface water and sediment qualities of the transboundary Medjerda River and its tributaries, influenced by industrial, urban, and agricultural wastes. Surface water samples, taken from five control points during humid and dry periods, were analyzed for physico-chemical, heavy metals, by atomic absorption, and bacteriological parameters (most probable number technique (MPN)). The highest values obtained respectively during the humid and the dry periods were 8.08 and 8.05 for pH; 5300 and 6440 μS cm-1 for conductivity; 1320 and 1325.21 mg L-1 for chloride; 3.22 and 4.37 mg L-1 for nitrates; 4240 and 5152 mg L-1 for total dissolved solids; 7.1.104 and 5.18.106 MPN /100 ml for fecal coliforms; 3.82.104 and 7.59.105 MPN/100 ml for Escherichia coli; and 6.99.102 and 9.25.106 MPN/100 ml for fecal streptococci. In parallel, sediments were assessed (n=4) for metallic and bacteriological contamination. Results of the calculation of the geo-accumulation index, enrichment factor, ecological risk, and risk index depicted severe metal contamination mainly by lead and cadmium, particularly in the Kasseb tributary. Anthropogenic activities are the main origins of metal pollution. The study also proves that the Medjerda ecosystem suffers from severe bacteriological contamination, expressed in MPN per Dry Matter (DM) (4.26 108 MPN g-1 of DM for fecal coliforms and 4.57 108 MPN g-1 of DM for fecal streptococci). Two water quality indexes (CCME-WQI and AWQI) were used, for the first time, to ascertain the overall quality and the suitability of the Medjerda River water for drinking. Both argued on its poor and unsuitable quality. The extent of the assessed pollution implies that the situation is frightening to the biota and its users. Regular quality assessment of this ecosystem is compulsory to control its pollution and to guarantee human health safety.
International Journal of Environmental Research and Public Health, 2022
Wastewater sludge represents an important resource for reuse in agriculture. However, potentially... more Wastewater sludge represents an important resource for reuse in agriculture. However, potentially harmful pathogens are a main threat in this context. Thus, the aim of this study was to examine the presence of helminth ova and protozoan cysts in dried sewage sludge samples collected from ten wastewater treatment plants (WWTPs) located in eight governorates in Tunisia. Based on morphological criteria, protozoan cysts of Giardia spp., Entamoeba histolytica/dispar/moshkovskii, and Entamoeba coli, were detected in all dried sludge composite samples (N = 116) from the investigated WWTPs. The mean concentration ranged from 1.4 to 10.7 cysts per 100 g dry matter (DM). The identified helminth eggs were Ascaris spp., Strongyles, Taeniid eggs, Hymenolepis nana, Enterobius vermicularis, and hookworm species. Ascaris spp. and Taeniid eggs were detected in 56.9 and 74.1% of analyzed samples, respectively. The presence of Trichuris spp., Hymenolepis diminuta, and Toxocara spp. eggs in dried sewag...
Une etude parasitologique a ete realisee sur des echantillons d’eaux usees et de boues residuaire... more Une etude parasitologique a ete realisee sur des echantillons d’eaux usees et de boues residuaires collectes a partir de sept stations d’epuration situees en Tunisie entre les mois de septembre et de decembre 2005. Parmi les 28 echantillons etudies, 100 % sont retrouves positifs avec une predominance constante des kystes de protozoaires sur les œufs d’helminthes. Les resultats obtenus ont permis d’evaluer la technique de detection adoptee (technique de Bailenger) et l’efficacite relative du procede de traitement (boues activees et lagunage). Tous les echantillons d’eaux usees brutes contiennent des kystes d’Entamoeba coli, d’Entamoeba histolytica/dispar et des kystes de Giardia sp. Au cours du traitement, la totalite des œufs et la majorite des kystes sont eliminees. Dans les echantillons d’eaux usees traitees, les rendements epuratoires sont donc de 100 % pour les œufs d’helminthes et compris entre 82 et 100 % pour les kystes de protozoaires suivant la filiere de traitement et le m...
Water and Sanitation for the 21st Century: Health and Microbiological Aspects of Excreta and Wastewater Management (Global Water Pathogen Project), 2019
Private cisterns or underground tanks may be at risk for certain types of contamination associate... more Private cisterns or underground tanks may be at risk for certain types of contamination associated with adverse health effects. This first and preliminary study evaluated the parasitological quality of drinking water stored in home-based cisterns in rural areas in seven delegations of the Kairouan Governorate in the center of Tunisia. The practices of water management and hygiene were also surveyed in addition to details related to the age and the kind of material used to make these home-based tanks. To achieve this purpose, 39 samples from five different sources—(i) rain water, (ii) truck cisterns, (iii) a mix of these two, (iv) wells, and (v) stored tap water—were collected and examined for the presence of parasites using the Bailenger modified technique. Microscopic/morphological analysis showed the presence of three gastrointestinal protozoa: Giardia duodenalis (10–380 cysts/L), Entamoeba histolytica/dispar/moshkovskii (30–400 cysts/L), and Entamoeba coli (20–200 cysts/L). These...
Le processus de photosensibilisation (phototraitement) de l'eau suscite beaucoup d'intérê... more Le processus de photosensibilisation (phototraitement) de l'eau suscite beaucoup d'intérêt, car il implique trois composants qui sont individuellement inoffensifs pour le milieu biologique, à savoir le photosensibilisant, la lumière et l'oxygène moléculaire. La photostabilité de la porphyrine tétra-méso-cationique (T4MPyP) dans l'eau usée et l’efficacité du phototraitement dépend de la concentration du photosensibilisant, de la qualité de l'eau (contaminants organiques, turbidité, pH, taux d'oxygène dissous et épaisseur de la lame d'eau) ainsi que de l'intensité et de la nature du rayonnement lumineux. L’étude expérimentale consistait à apporter à un sol sableux i) de l’eau usée secondaire traitée par boues activées, ii) la même eau usée, mais phototraitée avec 5 μM∙L-1 de T4MPyP pendant 6 h d’ensoleillement, et iii) une eau de puits. L’eau usée phototraitée était conforme aux normes tunisiennes (NT 106.03) pour l’irrigation sans restriction au niveau...
Limited access to safe water enhances poverty, hunger and diseases. This study evaluated the drin... more Limited access to safe water enhances poverty, hunger and diseases. This study evaluated the drinking water quality stored in home-based systems, located in rural areas of Tunisia. Water management was also documented as an improvement of good practice as most of the water contamination could be related to behavioral patterns. Thirty-nine water samples from five different sources (rainwater, truck cistern, mix, etc.) were screened for enteric parasitic contamination with the modified Bailenger technique. This technique allowed the detection of three protozoa: Giardia spp.; Entamoeba histolytica/dispar/moshkovskii; Entamoeba coli and one helminth specie: Ascaris spp. The overall prevalence of these intestinal parasites was approximately 97% with a relatively high frequency of protozoa over helminths and more specifically E. histolytica/dispar/moshkovskii. This incidence could be correlated to the lack of hygiene practices, sanitation and education. This situation requires the need fo...
The present study aimed to: (i) identify helminth eggs and protozoan cysts in wastewater samples ... more The present study aimed to: (i) identify helminth eggs and protozoan cysts in wastewater samples to which both human and animals could be exposed when they are reused in agriculture; and (ii) evaluate the efficiency of their removal by two wastewater treatment systems (activated sludge and lagoon). For these purposes, 234 wastewater samples (117 raw, 117 treated) were collected from 20 wastewater treatment plants (WWTPs) in Tunisia over a one-year sampling period. Parasitic load was enumerated by the modified Bailenger method. The results showed that helminth eggs found were Nematodes mainly represented by Ascaris sp. (95%), Hookworm species (50%), and Enterobius vermicularis (45%). For Cestodes, species identified were Taeniid eggs (85%), Hymenolepis nana (70%), Hymenolepis diminuta (55%) and digestive Strongyles. Among protozoa, Giardia sp., Entamoeba histolytica/dispar/moshkovskii and Entamoeba coli cysts were found in 100% of raw wastewater samples. The overall removal efficienc...
Helminth eggs and protozoan cysts were enumerated in raw and treated wastewater in Tunisia in ord... more Helminth eggs and protozoan cysts were enumerated in raw and treated wastewater in Tunisia in order to determine their removal by wastewater treatment and to provide quantitative data for developing regulations for wastewater quality that are currently lacking. Raw and treated wastewater samples were collected from 17 plants in Tunisia during 2006-2007 and analyzed for parasites using the modified Bailenger method. Two groups of parasites, namely, Ascaris sp., Entamoeba coli, Enterobius vermicularis, and Taenia sp. (group 1) and Entamoeba histolytica/dispar, Giardia sp., and Taenia sp. (group 2) could statistically be distinguished according to their removal by wastewater treatment. Group 1 parasites were removed by 1.1 log(10) (92.4%) and group 2 parasites by 0.61 log(10) (76%). The ubiquitous presence of parasitic protozoa in Tunisian wastewater and ineffective wastewater treatment lead to their proliferation in surface waters with a high probability of exposure of human and animals to these parasites and consequent adverse health effects, as is apparent from epidemiologic data as well. This study provides a quantitative basis for risk assessment studies and development of mitigation strategies, such as improving wastewater treatment efficiency.
The aim of this study was to evaluate the photobactericidal effect of four photosensitizers (PSs)... more The aim of this study was to evaluate the photobactericidal effect of four photosensitizers (PSs) with different structural and physico-photochemical properties, namely mesotetracationic porphyrin (T4MPyP), dianionic rose Bengal (RB), monocationic methylene blue (MB) and neutral red (NR). Their photokilling activity was tested in vitro on pathogenic bacteria such as Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) suspended in nutrient broth (NB) and in phosphate buffered saline (PBS) through following their influence on the PSs antimicrobial efficacy. Photodynamic inactivation (PDI) experiments were performed using visible light (L) and different PSs concentrations (20–70 μM). The ability of these PSs to mediate bacterial photodynamic inactivation was investigated as a function of type of PS and its concentrations, spectral and physico-chemical properties, bacterial strain, irradiation time and suspending medium. Indeed, they showed antibacterial effects...
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