Molecular and computational characterization of ABCB11 and ABCG5 variants in Tunisian patients with neonatal/infantile low-GGT intrahepatic cholestasis: Genetic diagnosis and genotype-phenotype correlation assessment.

Many inherited conditions cause hepatocellular cholestasis in infancy, including progressive familial intrahepatic cholestasis (PFIC), a heterogeneous group of diseases with highly overlapping symptoms. In our study, six unrelated Tunisian infants with PFIC suspicion were the subject of a panel-target sequencing followed by an exhaustive bioinformatic and modeling investigations. Results revealed five disease-causative variants including known ones: (the p.Asp482Gly and p.Tyr354 * in the ABCB11 gene and the p.Arg446 * in the ABCC2 gene), a novel p.Ala98Cys variant in the ATP-binding cassette subfamily G member 5 (ABCG5) gene and a first homozygous description of the p.Gln312His in the ABCB11 gene. The p.Gln312His disrupts the interaction pattern of the bile salt export pump as well as the flexibility of the second intracellular loop domain harboring this residue. As for the p.Ala98Cys, it modulates both the interactions within the first nucleotide-binding domain of the bile transporter and its accessibility. Two additional potentially modifier variants in cholestasis-associated genes were retained based on their pathogenicity (p.Gly758Val in the ABCC2 gene) and functionality (p.Asp19His in the ABCG8 gene). Molecular findings allowed a PFIC2 diagnosis in five patients and an unexpected diagnosis of sisterolemia in one case. The absence of genotype/phenotype correlation suggests the implication of environmental and epigenetic factors as well as modifier variants involved directly or indirectly in the bile composition, which could explain the cholestasis phenotypic variability.

Hypoparathyroidism in children: a study of eight cases.

BACKGROUND: Hypoparathyroidism is a rare pediatric endocrine disease, which is caused by low circulating levels of PTH or insensitivity to its action in the target tissues. AIM: To report the clinical and biochemical characteristics and theoutcome of 8 patients with hypoparathyroidism. METHODS: We analyzed retrospectively the results of clinical, biochemical, radiological findings of patients with hypoparathyroidism diagnosed in pediatric department of Hedi Chaker Hospital during the period 1994-2013. RESULTS: Eight patients (5 females and 3 males) were diagnosed with hypoparathyroidism during 20 years's period. The median age at the onset of first symptoms was 17,5 months (15 days- 5 years and 10 months). Seizures were the most commonly presenting symptom and were seen in seven cases. Eight patients were diagnosed with hypoparathyroidism (Di-Georges syndrome: one case, Sanjad Sakati syndrome: 3 case, kearns sayre syndrome: 1 case, autoimmune polyendocrinopathy candidiasis- ectodermal dystrophy: one case, idiopathic hypoparathyroidism: two cases. Conventional treatment was based on calcium and vitamin D analogs. The average of follow up was 5 years. Nephrocalcinosis was noted in two patients. The death occurred in five patients; it was related to hypocalcaemia in one patient. CONCLUSION: The diagnosis of hyperparathyroidism is easy; it's established on the association of hypocalcaemia and hyperphosphatemia. Etiologic approach is based on molecular findings. Vitamin D analog treatment of hypoparathyroidism in children involves the challenge, of adjusting treatment dosage to minimize both symptomatic hypocalcemia and asymptomatic, but potentially kidney-damaging, hypercalciuria causing nephrocalcinosis and renal insufficiency.

Report of the Tunisian Registry of Primary Immunodeficiencies: 25-Years of Experience (1988-2012).

PURPOSE: Primary immunodeficiencies (PIDs) are a large group of diseases characterized by susceptibility to not only recurrent infections but also autoimmune diseases and malignancies. The aim of this study was to describe and analyze the distribution, clinical features and eventual outcome of PID among Tunisian patients. METHODS: We reviewed the record of 710 patients diagnosed with Primary Immunodeficiency Diseases (PIDs) from the registry of the Tunisian Referral Centre for PIDs over a 25-year period. RESULTS: The male-to-female ratio was 1.4. The median age at the onset of symptoms was 6 months and at the time of diagnosis 2 years. The estimated prevalence was 4.3 per 100,000 populations. The consanguinity rate was found in 58.2 % of families. According to the International Union of Immunological Societies classification, spectrums of PIDs were as follows: combined T-cell and B-cell immunodeficiency disorders account for the most common category (28.6 %), followed by congenital defects of phagocyte (25.4 %), other well-defined immunodeficiency syndromes (22.7 %), predominant antibody deficiency diseases (17.7 %), diseases of immune dysregulation (4.8 %), defect of innate immunity (0.4 %) and complement deficiencies (0.4 %). Recurrent infections, particularly lower airway infections (62.3 %), presented the most common manifestation of PID patients. The overall mortality rate was 34.5 %, mainly observed with combined immunodeficiencies. CONCLUSION: The distribution of PIDs was different from that reported in Western countries, with a particularly high proportion of Combined Immunodeficiencies and phagocyte defects in number and/or function. More is needed to improve PID diagnosis and treatment in our country.

Hemolytic anemia and metabolic acidosis: think about glutathione synthetase deficiency.

Glutathione synthetase deficiency (GSSD) is a rare disorder of glutathione metabolism with varying clinical severity. Patients may present with hemolytic anemia alone or together with acidosis and central nervous system impairment. Diagnosis is made by clinical presentation and detection of elevated concentrations of 5-oxoproline in urine and low glutathione synthetase activity in erythrocytes or cultured skin fibroblasts. The prognosis seems to depend on early diagnosis and treatment. We report a 4 months old Tunisian male infant who presented with severe metabolic acidosis with high anion gap and hemolytic anemia. High level of 5-oxoproline was detected in her urine and diagnosis of GSSD was made. Treatment consists of the correction of acidosis, blood transfusion, and supplementation with antioxidants. He died of severe metabolic acidosis and sepsis at the age of 15 months.

Neonatal purulent meningitis in southern Tunisia: Epidemiology, bacteriology, risk factors and prognosis.

OBJECTIVES: To study the epidemiological, clinical and bacteriological aspects and outcome of purulent neonatal meningitis (PNM). METHODOLOGY: Retrospective analysis of 55 cases of PNM hospitalized in the pediatric ward of Hedi Chaker Hospital from 1990 to 2012. Infants less than 29 days of age were included. The diagnosis was made on either the presence of bacteria in the cerebrospinal fluid (CSF) or the combination of pleocytosis >30 cells/mm(3), protein level >1.3 g/l and glucose level <2.2 mmol/l or CSF/blood glucose ratio <0.4. RESULTS: The male:female sex ratio was 1.75. One or more maternal risk factors for infection were found in 24 cases. The main symptoms were fever and poor feeding. Soluble antigen was positive in four cases and cultures had isolated the bacteria in 28 cases. The mortality rate was 40%. The sequelae rate in the survivors was 16.4%. CONCLUSION: This study emphasizes the severity of PNM with high rates of mortality and neurological sequelae.

Congenital heart disease in 37,294 births in Tunisia: birth prevalence and mortality rate.

AIM: To investigate the previously unknown birth incidence, treatment, and mortality of children with congenital heart disease in Tunisia. METHODS: We undertook a retrospective review of medical records of all patients who were born in 2010 and 2011, and were diagnosed in Sfax (Tunisia) with congenital heart defect. RESULTS: Among 37,294 births, 255 children were detected to have congenital heart disease, yielding a birth incidence of 6.8 per 1000. The most frequently occurring conditions were ventricular septal defects (31%), ostium secundum atrial septal defects (12.9%), and pulmonary valve abnormalities (12%). Coarctation of the aorta, tetralogy of Fallot, univentricular physiology, pulmonary atresia with ventricular septal defect, and transposition of the great arteries were found in 4.3%, 6.2%, 3.4%, 2.7%, and 2.7%, respectively. During the follow-up of 1 year, 23% of the children died. About three-quarters of those deaths happened before surgery. CONCLUSION: The present study is in line with the general estimates in the world. It has revealed a high case of mortality among the patients awaiting corrective surgery. These children need more facilities.

Hemolytic anemia and progressive neurologic impairment: think about triosephosphate isomerase deficiency.

We have reported the first Tunisian case of triosephosphate isomerase (TPI) deficiency in a 2-year-old girl. She was the first child of a nonconsanguineous couple. The disease included a neonatal onset of chronic hemolytic anemia, recurrent low-respiratory infections then progressive neurological involvement. The diagnosis was made after her death from the TPI values of her parents who exhibited intermediate enzyme deficiency. Molecular study of TPI genes showed that the father and the mother are heterozygous for Glu105Asp mutation. Pediatricians must be alert to the differential diagnosis in patients having hemolytic anemia and other concomitant manifestations.

[Bacterial meningitis in children: epidemiological data and outcome]. / La méningites purulentes de l'enfant dans le sud Tunisien: aspects épidémiologiques et évolutifs.

BACKGROUND: The bacterial meningitis in children remains a worrisome affection both by its frequency and by its gravity. AIM: describe the epidemiological, clinical and evolutionary data of bacterial meningitis in children aged between 3 months and 15 years. METHODS: we conducted a retrospective study of all cases of bacterial meningitis collected in the department of pediatrics of Hedi Chaker hospital, during a period of 6 years (2006-2011). We analyzed the files retrospectively and we studied the epidemiological data and the outcome. RESULTS: Thirty cases of bacterial meningitis were recorded. The most frequent species were Streptococcus pneumoniae and Haemophilus influenzae followed by Neisseria meningitidis with respectively 43%, 40%, and 6% of cases. The yearly distribution of these bacteria showed an increase of the rate of the bacterial meningitis during the last 2 years. The average age of our patients was 1 year 6months (3 months-13 years). All the patients were vaccinated according to the Tunisian vaccination calendar; and none of them had pneumococcal vaccine or the Hib vaccine. The main clinical manifestations were fever (100 %), seizures (14 %) and vomiting (44 %). Bulging fontanel was noted in 15cas (55 %), somnolence in 11 cases (40 %) and axial hypotonia in 12 cases (44 %). In the outcome, the neurological sequelae were showed in eight patients (26%). CONCLUSION: In our study, H. influenzae and S. pneumoniae were the main microorganisms responsible for bacterial meningitis. We strongly recommend the introduction pneumococcal vaccine in our vaccination calendar.

[Cerebral imaging in epileptic children: study of 140 cases]. / Magerie cérébrale de l'épilepsie de lenfant. Etude de 140 observations.

BACKGROUND: Epilepsy is a chronic disease, often with an onset during childhood and characterized by spontaneous and recurrent seizures. It concerns 0.5-1% of children under 16 years of age. Being much more sensitive than computed tomography, magnetic resonance imaging is the technique of choice to identify an underlying cause. CT scan is used in emergency situations. AIM: To describe cerebral lesions in epilepetic children and to identify predicative factors of abnormal neuroimaging. METHODS: Authors present a retrospective descriptive study of Neuroimaging data of 140 epileptic children evaluated for a period from 2000-2007 in the paediatric departement of Sfax. RESULTS: The mean age at onset of seizures was 3 years. The sex ratio was 1.12. Psychomotor retardation was noted in 75 patients. The seizures were generalized in 75% of case. Neurological examination was abnormal in 73 cases (52%). The main indications for conducting a brain imaging were psychomotor retardation (65 cases) and focal onset seizures (25 cases). Anoxo-ischemic lesions were the most frequent cerebral anomalies followed by brain malformations. Predictors of pathological MRI were an age at onset of seizure <3 years, psychomotor retardation and abnormal neurological examination. CONCLUSION: The morphological imaging is recommended for recent seizures of the child with the exception of idiopathic epilepsies. MRI is the best imaging modality in exploration of epilepsy in this context.

[Primary immune thrombocytopenia in childhood: a regional study in the south of Tunisia]. / Thrombocytopénie immune primaire de L'Enfant: etude régionale dans le sud Tunisien.

BACKGROUND: the primary immune thrombocytopenia (ITP) in children has a favorable evolution in most of cases. aim: describe the epidemiological and therapeutic data and the outcome of primary immune thrombocytopenia in our patients and propose a treatment plan to standardize the management of this disease in our region. methods: We conducted a retrospective study of 140 cases of primary immune thrombocytopenia collected in department of pediatrics and hematology of Hedi Chaker hospital during a period of 15 years. Patients who had a platelet count ≤ 20 000 and / or mucosal or troublesome lifestyle hemorrhage were treated. results: The mean age was 6 years 7 months with extremes varying from 3 months to 15 years. The bleeding manifestations were dominated by cutaneous bleeding in the form of petechiae or bruise (100%). Epistaxis and gingivorragia were noted in 32,9% and 25,7% of the cases respectively. The most of patient were treated with corticosteroids (79%). Intravenous immunoglobulin was associated with corticosteroids in 7%. An acute ITP occurred in 94 cases (67%) and a chronic ITP in 30 cases (21%). CONCLUSION: In the recently diagnosed ITP, the response delay under association Intravenous immunoglobulin and corticoids is shorter than that of corticoids alone, but the high cost of Intravenous immunoglobulin associated with their immediate side effects compels us to recommend corticoids as a first line of treatment.

[Rheumatic cardiopathies and its risk factors: about 50 cases]. / Les complications cardiaques du rhumatisme articulaire aigu et ses facteurs de risque : étude de 50 observations.

INTRODUCTION: Acute rheumatic fever (ARF) is a multi-systemic disease, in which cardiac involvement is the most serious major manifestation of disease. The aim of this study was to analyse cardiac involvement in children with ARF and his risk factors. MATERIALS AND METHODS: It were a retrospective study including all children under the age of 14 years who were hospitalized for ARF in the pediatric department of the CHU Hédi Chaker of Sfax, during a period of twelve years (2010-2022). RESULTS: We collected 50 cases (31 boys and 19 girls). Twenty-two patients (44%) developed cardiac lesions. The mean age at diagnosis was 9.6 years [5-14 years]. A pathological heart murmur was detected in 14 cases (n = 14/22) was classified as mild carditis in 15 cases, moderate carditis in 5 cases and severe in 2 cases. The median follow-up time was 3,3 years. Nineteen patients developed valvular sequelae Risk factors of cardiac lesions was: age more than 8 years, heart murmur, allonged PR, CRP > 100 mg/l and VS > 100 mm. CONCLUSION: CR is still a public health problem in Tunisia. It is a serious pathology that can cause serious increases in morbidity rates. Thus, we must strengthen preventive strategies.

A novel MT-CO1 m.6498C>A variation associated with the m.7444G>A mutation in the mitochondrial COI/tRNA(Ser(UCN)) genes in a patient with hearing impairment, diabetes and congenital visual loss.

Mitochondrial diseases are a clinically heterogeneous group of disorders that arise as a result of dysfunction of the mitochondrial respiratory chain. Sensorineural hearing loss (SNHL) has been described in association to different mitochondrial multisystem syndromes, often involving the central nervous system, neuromuscular, or endocrine organs. In this study, we described a Tunisian young girl with hearing impairment, congenital visual loss and maternally inherited diabetes. No mutation was found in the mitochondrial tRNA(Leu(UUR)) and the 12S rRNA genes. However, we detected the m.7444G>A mutation in the mitochondrial COI/tRNA(Ser(UCN)) genes. This mutation eliminates the termination codon of the MT-CO1 gene and extends the COI polypeptide by three amino acids (Lys-Gln-Lys) to the C-terminal. The whole mitochondrial genome screening revealed the presence of a novel mutation m.6498C>A (L199I) in the mitochondrial DNA-encoded subunit I of the cytochrome c oxidase (COX). This "probably damaging" transversion affects a highly conserved domain and it was absent in 200 Tunisian controls. The studied patient was classified under the haplogroup H2a.

Nephropathic infantile form of cystinosis about one case.

Cystinosis is the major cause of inherited Fanconi syndrome, and should be suspected in young children with a failure to thrive and with signs of renal proximal tubular damage. This is a study of a case report of cystinosis revealed by a growth failure and chronic dehydration. A 9-month-old boy was referred to our department for evaluation of polyuria and polydipsia. Clinical examination showed dehydration and enlarged wrists and rachitic rosaries. The presence of metabolic acidosis, hypokalemia, hypochloremia with proteinuria, polyuria, and hypercalciuria was suggestive of inherited Fanconi syndrome. The diagnosis of cystinosis was confirmed by an increased leukocyte cystine level.

[Primary immunodeficiency disorders in 51 cases]. / Les déficits immunitaires primitifs de l'enfant. Etude de 51 observations.

BACKGROUND: Primary immunodeficiency disorders (PID) are a heterogeneous group of diseases, characterized by an increased susceptibility to infections. AIM: To determine the frequency of PID in south of Tunisia to collect information on clinical experience with these disorders. METHODS: Over a period of 16 years (1995 - 2010), primary immunodeficiency was confirmed in 51 patients (31 boys and 20 girls). The immunological investigation included a study of specific and/or non specific humoral and cellular immunity. RESULTS: These 51 patients belonged to 47 families among which 37 were consanguine (80%). The immunological investigations revealed a cellular or combined immunodeficiency in 21 cases, with a majority of ataxia-telangiectasia syndromes (11 cases), HLA class II deficiency (9 cases). A predominant antibody defect was found in 3 patients and a chronic granulomatous disease in seven cases. Deaths occurred So far in 19 patients (37 %). CONCLUSIONS: PID are relatively frequent in Tunisia, probably because of the high rate of consanguinity among the general population. The distribution of the different groups of primary immunodeficiencies is characterized by high frequency of ataxia - telangiectasia and HLA class II deficiency.

Clinical and therapeutic characteristics of childhood uveitis in a tertiary center in Tunisia.

INTRODUCTION: Childhood uveitis is a rare condition with various associated diagnostic and therapeutic challenges. AIM: We proposed to describe the distribution, clinical findings, treatment, complications, and visual outcomes of uveitis in children at a tertiary referral center in Sfax, Tunisia. METHODS: A retrospective study of 33 children (54 eyes) with uveitis collected over the period from January 2009 to December 2018 was carried out at the Ophthalmology Department of Habib Bourguiba University Hospital, Sfax, Tunisia. The data from the clinical examination, the etiological assessment, and the used treatments were collected. Standard diagnostic criteria were used for all uveitic syndromes or entities. RESULTS: The mean age of the patients was 11.42 years with a male-to-female ratio of 0.74. Uveitis was bilateral in 63% of the patients. The most common anatomical form was intermediate uveitis (39%). Idiopathic cases accounted for 52%. The major complications were posterior synechiae, optic disc edema, cataract, and cystoid macular edema. Anti-infective treatment was prescribed in 24% of the patients. Oral corticosteroid therapy was used in 67% of the patients. 18% of the patients received immunosuppressive therapy and 6% received a biological agent. The mean final visual acuity was 4.6/10. CONCLUSION: Childhood uveitis is a serious pathology with frequent and vision-threatening complications. The etiologies are variable and the assessment can remain negative. A rigorous diagnostic approach, an oriented etiological assessment in collaboration with the pediatrician, and an appropriate therapy are necessary for management.

Preparation and Characterization of New and Low-Cost Ceramic Flat Membranes Based on Zeolite-Clay for the Removal of Indigo Blue Dye Molecules.

Composite flat membranes were prepared using a dry uniaxial pressing process. The effect of the sintering temperature (850-950 °C) and smectite proportion (10-50 wt.%) on membrane properties, such as microstructure, mechanical strength, water permeability, and treatment performances, was explored. It was observed that increasing the sintering temperature and adding higher amounts of smectite increased the mechanical strength and shrinkage. Therefore, 850 °C was chosen as the optimum sintering temperature because the composite membranes had a very low shrinkage that did not exceed 5% with high mechanical strength, above 23 MPa. The study of smectite addition (10-50 wt.%) showed that the pore size and water permeability were significantly reduced from 0.98 to 0.75 µm and from 623 to 371 L·h-1·m-2·bar-1, respectively. Furthermore, the application of the used membranes in the treatment of indigo blue (IB) solutions exhibited an almost total turbidity removal. While the removal of color and COD decreased from 95% to 76%, respectively, they decreased from 95% to 52% when the amount of smectite increased. To verify the treated water's low toxicity, a germination test was performed. It has been shown that the total germination of linseed grains irrigated by MS10-Z90 membrane permeate was identical to that irrigated with distilled water. Finally, based on its promising properties, its excellent separation efficiency, and its low energy consumption, the MS10-Z90 (10 wt.% smectite and 90 wt.% zeolite) sintered at 850 °C could be recommended for the treatment of colored industrial wastewater.

A novel m.12908T>a mutation in the mitochondrial ND5 gene in patient with infantile-onset Pompe disease.

Pompe disease is a progressive metabolic myopathy caused by deficiency in lysosomal acid α-glucosidase and results in cellular lysosomal and cytoplasmic glycogen accumulation. A wide spectrum of clinical phenotypes exists from hypotonia and severe cardiac hypertrophy in the first few months of life to a milder form with the onset of symptoms in adulthood. The disease is typically due to severe mutations in GAA gene. In the present study, we described a newborn boy with clinical features of Pompe disease particularly with hypertrophic cardiomyopathy, hypotonia and hepatomegaly. This case was at first misdiagnosed as mitochondrial disorder. Accordingly, we performed a mitochondrial mutational analysis that revealed a novel mutation m.12908T>A in the ND5 gene. Secondary structure analysis of the ND5 protein further supported the deleterious role of the m.12908T>A mutation, as it was found to involve an extended imbalance in its hydrophobicity and affect its function.

Febrile seizures: an epidemiological and outcome study of 482 cases.

INTRODUCTION: Febrile seizures (FSs) are the most common type of seizures seen in children. After the first FS, 3 to 12% of children develop epilepsy, and 30% of these patients present with recurrent FS. The purpose of this study was to describe the epidemiological aspects of FS in order to better define the long-term outcomes in children with first FS and to identify the risk factors associated with the recurrence of FS as well as the development of epilepsy. METHODS: A retrospective study of 482 children with FS was conducted from January of 2004 to December of 2009 in the pediatric department of Hedi Chaker University Hospital in Sfax, Tunisia. The medical records for each patient were first collected and then analyzed at a later time. RESULTS: The study included 482 children. Simple FSs were found in 55.2% of children, and complex FSs were observed in 44.8%. The mean duration for follow-up examinations was 2 years and 4 months, and ranged from 1 to 5 years. No deaths or permanent neurological deficits due to FSs were observed, and only six children (1%) developed epilepsy. A total of 57 children (11.7%) developed recurrent seizures. Our findings suggest that a family history of FS, young age at onset, and a low degree of fever were predictive of recurrent FSs. CONCLUSION: Children with FSs encounter a minor risk of mortality and morbidity. While recurrent seizures are observed in these children, only a minority of these patients develop epilepsy.

Treatment of Tuna Cooking Juice via Ceramic Ultrafiltration Membrane: Optimization Using Response Surface Methodology.

In the present work, optimized ultrafiltration conditions, using a ceramic multi tubular titania membrane (150 KDa), were investigated for the treatment of tuna cooking juice, for water reuse in the industrial process. The interactive effects of the volume concentrating factor (VCF) (1.03-4.25), feed temperature (T) (20-60 °C), and applied transmembrane pressure (ΔP) (2-5 bar) on protein removal (R protein) and permeate flux (J) were determined. A Box-Behnken experimental design (BBD) with the response surface methodology (RSM) was used for statistical analysis, modeling, and optimization of the operating conditions. The analysis of variance (ANOVA) results proved that the protein removal and permeate flux were significant and represented good correlation coefficients of 0.9859 and 0.9294, respectively. Mathematical modeling showed that the best conditions were VCF = 1.5 and a feed temperature of 60 °C, under a transmembrane pressure of 5 bar. The fouling mechanism was checked by applying a polarization concentration model. Determination of the gel concentration confirmed the results found in the mass balance calculation and proved that the VCF must not exceed 1.5. The membrane regeneration efficiency was proven by determining the water permeability after the chemical cleaning process.

Statistical Simulation, a Tool for the Process Optimization of Oily Wastewater by Crossflow Ultrafiltration.

This work aims to determine the optimized ultrafiltration conditions for industrial wastewater treatment loaded with oil and heavy metals generated from an electroplating industry for water reuse in the industrial process. A ceramic multitubular membrane was used for the almost total retention of oil and turbidity, and the high removal of heavy metals such as Pb, Zn, and Cu (>95%) was also applied. The interactive effects of the initial oil concentration (19−117 g/L), feed temperature (20−60 °C), and applied transmembrane pressure (2−5 bar) on the chemical oxygen demand removal (RCOD) and permeate flux (Jw) were investigated. A Box−Behnken experimental design (BBD) for response surface methodology (RSM) was used for the statistical analysis, modelling, and optimization of operating conditions. The analysis of variance (ANOVA) results showed that the COD removal and permeate flux were significant since they showed good correlation coefficients of 0.985 and 0.901, respectively. Mathematical modelling revealed that the best conditions were an initial oil concentration of 117 g/L and a feed temperature of 60 °C, under a transmembrane pressure of 3.5 bar. In addition, the effect of the concentration under the optimized conditions was studied. It was found that the maximum volume concentrating factor (VCF) value was equal to five and that the pollutant retention was independent of the VCF. The fouling mechanism was estimated by applying Hermia's model. The results indicated that the membrane fouling given by the decline in the permeate flux over time could be described by the cake filtration model. Finally, the efficiency of the membrane regeneration was proved by determining the water permeability after the chemical cleaning process.