Utilizing anaerobic substrate distribution for growth of aerobic granular sludge in continuous-flow reactors.

The development of continuous flow reactors (CFRs) employing aerobic granular sludge (AGS) for the retrofit of existing wastewater treatment plants (WWTPs) using a continuous-flow activated sludge (CFAS) system has garnered increasing interest. This follows the worldwide adoption of AGS technology in sequencing batch reactors (SBRs). The better settleability of AGS compared to AS allows for process intensification of existing wastewater treatment plants without the difficult conversion of often relatively shallow CFRs to deeper AGS-SBRs. To retrofit existing CFAS systems with AGS, achieving both increased hydraulic capacity and enhanced biological nutrient removal necessitates the formation of granular sludge based on the same selective pressures applied in AGS-SBRs. Previous efforts have focussed mainly on the selective wasting of flocculent sludge and retaining granular sludge to drive aerobic granulation. In this study a pilot-scale CFR was developed to best mimic the implementation of the granulation mechanisms of full-scale AGS-SBRs. The pilot-scale reactor was fed with pre-settled municipal wastewater. We established metrics to assess the degree to which the proposed mechanisms were implemented in the pilot-scale CFR and compared them to data from full-scale AGS-SBRs, specifically with respect to the anaerobic distribution of granule forming substrates (GFS). The selective pressures for granular sludge formation were implemented through inclusion of anaerobic upflow selectors with a water depth of 2.5 meters, which yielded a sludge with properties similar to AGS from full-scale SBRs. In comparison to the CFAS system at Harnaschpolder WWTP treating the same pre-settled wastewater, a more than twofold increase in volumetric removal capacity for both phosphorus and nitrogen was achieved. The use of a completely mixed anaerobic selector, as opposed to an anaerobic upflow selector, caused a shift in EBPR activity from the largest towards the smallest size class, while nitrification was majorly unaffected. Anaerobic selective feeding via bottom-feeding is, therefore, favorable for the long-term stability of AGS, especially for less acidified wastewater. The research underlines the potential of AGS for enhancing the hydraulic and biological treatment capacity of existing CFAS systems.

Vitamin D deficiency in young children with iron deficiency in Misan province, Iraq.

This study aimed to assess vitamin D status and its association with iron status in young Iraqi children. A total of 95 infants and toddlers with iron deficiency (ages ranging from 6 to 24 months) and an equal number of 95 healthy subjects with normal hemoglobin (Hb) and sufficient ferritin level with matching age were included as a control group. A specially designed questionnaire was used to collect data. The cases were classified into iron deficiency (ID) and iron deficiency anemia (IDA) according to hemoglobin and ferritin levels. The cases and control groups were subdivided into vitamin insufficiency (VDI), vitamin D deficiency (VDD), and vitamin D sufficiency groups according to 25-hydroxyvitamin D [25(OH)D] levels. Young children with IDA have significantly lower serum levels of 25(OH) D compared with ID and control groups (p<0.05). According to iron status, VDI and VDD were present in 20% and 70% of IDA, 25.7% and 60%of ID, and 26.3% and 30.5% of control groups, respectively, with a significant difference in vitamin D level (p<0.05) among studied groups. A significant positive correlation (p=0.000) was found between serum ferritin level and 25(OH) D level in studied patients. Young children with severe iron deficiency have a higher prevalence of vitamin D deficiency, and there was a significant positive correlation between serum ferritin level and 25(OH) D levels among studied children.

Late vitamin K deficiency bleeding in infants: five-year prospective study

Abstract Objective: To study the presenting clinical and demographic features, risk factors, and outcome of infants with late vitamin K deficiency bleeding. Methods: Over a 5-year study period, the presenting clinical features and outcome of all 47 infants observed aged less than 6 months, who were diagnosed with late-onset primary and secondary VKDB by detailed history, physical examination, and laboratory findings were evaluated. Confirmed primary late VKDB was diagnosed when no cause other than breastfeeding could be found, while in the secondary subtype additional risk factors compromising the vitamin K effect were diagnosed. Results: Secondary late VKDB (83%, 39 patients) was more common than the primary subtype. The mean age of patients was 10.50 ± 5.75 and 9.74 ± 6.04 weeks in primary and secondary VKDB subtypes, respectively, and the age of infants did not have a significant difference (> 0.05). The male to female ratio was 2.13:1. The residency, place and mode of delivery, gestational age, and types of feeding of patients did not have a significant difference between VKDB subtypes. The skin and gastrointestinal tract (GIT) (40.4%) followed by intracranial hemorrhage (ICH) (32%), were common sites of bleeding. Neurological complications were seen in 21% of patients; however, lethality was 23%, and the outcome of patients did not have a significant difference (p > 0.05) between VKDB subtypes. Conclusion: Secondary late VKDB is more common than the primary subtypes, and late VKDB is still a serious disease in developing countries, including Iraq, when vitamin K prophylaxis isn't routinely used at birth.

Relation of Serum Ferritin Level with Serum Hepcidin and Fucose Levels in Children with ß-Thalassemia Major.

The aim of this study was to assess serum ferritin, hepcidin, L-fucose, and protein binding fucose levels in ß-thalassemia major (ß-TM) patients and to correlate the serum ferritin level with hepcidin and fucose levels. A total 70 (26 males and 44 females) children with ß-TM, ages ranging from 5 to 16 years (mean age 8.3 ± 2.7 years) and 50 (25 males and 25 females) apparently healthy subjects with matching age and sex were included as a control group. An especially designed questionnaire was used to collect age, gender, body mass index (BMI), hemoglobin (Hb), serum ferritin, hepcidin-25 peptide, α-L-fucose, and protein binding fucose (PBF) levels. ß-Thalassemia major patients had significantly (p < 0.05) higher serum ferritin, fucose and PBF levels, but the serum hepcidin level was significantly (p < 0.05) lower when compared to the controls, and their levels were affected by the gender of the ß-TM patients, as it was significantly (p < 0.05) higher in female in comparison to male patients. There was no significant (p > 0.05) correlation between serum ferritin with hepcidin and fucose levels as a marker of iron overload in ß-TM. The regulation of hepcidin, and L-fucose levels in patients with ß-TM is more affected by erythropoeitic activity than by iron overload, as there was no significant correlation between serum ferritin with hepcidin and fucose levels as a marker of iron overload in ß-TM.

Late vitamin K deficiency bleeding in infants: five-year prospective study.

OBJECTIVE: To study the presenting clinical and demographic features, risk factors, and outcome of infants with late vitamin K deficiency bleeding. METHODS: Over a 5-year study period, the presenting clinical features and outcome of all 47 infants observed aged less than 6 months, who were diagnosed with late-onset primary and secondary VKDB by detailed history, physical examination, and laboratory findings were evaluated. Confirmed primary late VKDB was diagnosed when no cause other than breastfeeding could be found, while in the secondary subtype additional risk factors compromising the vitamin K effect were diagnosed. RESULTS: Secondary late VKDB (83%, 39 patients) was more common than the primary subtype. The mean age of patients was 10.50 ±â€¯5.75 and 9.74 ±â€¯6.04 weeks in primary and secondary VKDB subtypes, respectively, and the age of infants did not have a significant difference (p > 0.05). The male to female ratio was 2.13:1. The residency, place and mode of delivery, gestational age, and types of feeding of patients did not have a significant difference between VKDB subtypes. The skin and gastrointestinal tract (GIT) (40.4%) followed by intracranial hemorrhage (ICH) (32%), were common sites of bleeding. Neurological complications were seen in 21% of patients; however, lethality was 23%, and the outcome of patients did not have a significant difference (p > 0.05) between VKDB subtypes. CONCLUSION: Secondary late VKDB is more common than the primary subtypes, and late VKDB is still a serious disease in developing countries, including Iraq, when vitamin K prophylaxis isn't routinely used at birth.

Extraction of Structural Extracellular Polymeric Substances from Aerobic Granular Sludge.

To evaluate and develop methodologies for the extraction of gel-forming extracellular polymeric substances (EPS), EPS from aerobic granular sludge (AGS) was extracted using six different methods (centrifugation, sonication, ethylenediaminetetraacetic acid (EDTA), formamide with sodium hydroxide (NaOH), formaldehyde with NaOH and sodium carbonate (Na2CO3) with heat and constant mixing). AGS was collected from a pilot wastewater treatment reactor. The ionic gel-forming property of the extracted EPS of the six different extraction methods was tested with calcium ions (Ca2+). From the six extraction methods used, only the Na2CO3 extraction could solubilize the hydrogel matrix of AGS. The alginate-like extracellular polymers (ALE) recovered with this method formed ionic gel beads with Ca2+. The Ca2+-ALE beads were stable in EDTA, formamide with NaOH and formaldehyde with NaOH, indicating that ALE are one part of the structural polymers in EPS. It is recommended to use an extraction method that combines physical and chemical treatment to solubilize AGS and extract structural EPS.