Biofilm Accumulation and Sucrose Rinse Modulate the Calcium and Fluoride Bioavailability in the Saliva of Children with Early Childhood Caries

This quasi-experimental study aimed at investigating the combined effect of biofilm accumulation and 20% sucrose rinse on the modulation of calcium (Ca2+), phosphate (Pi), and fluoride (F-) bioavailability in saliva of children with early childhood caries (ECC). In-that, fifty-six preschoolers of both genders were evaluated according to caries experience and activity: caries-free (CF, n=28) and with ECC (n=28) and then, submitted to biofilm intervention (biofilm accumulation or no biofilm accumulation). In each situation, saliva samples were collected before and five minutes after a 20% sucrose rinse to determine the concentrations of Ca2+, Pi, and F−. Calcium concentration was significantly lower in the biofilm accumulation situation compared to the situation of biofilm mechanical control, except for children CF after sucrose rinse. Biofilm accumulation increased salivary calcium concentration in children with ECC after sucrose rinse, whereas mechanical biofilm control reduced it in both groups. The phosphate concentration was influenced by mechanical control of the biofilm in CF children. The fluoride bioavailability was reduced by sucrose rinse and biofilm accumulation in CF and ECC children. In conclusion, the combined effect of biofilm accumulation and sucrose rinse modifies the bioavailability of calcium and fluoride in the saliva of children with early childhood caries.

Enhanced removal of phosphate from wastewater by precipitation coupled with flocculation

Eco-friendly flocculants of alginic acid, NaHCO3 and CaCl2.2H2O with advantages of strong gelation characteristics were prepared for supporting the removal of phosphate in synthetic wastewater using CaO and Ca(OH)2 as precipitants. The effects of weight ratios of each component in flocculants, dosage of flocculants and initial phosphate concentration were investigated through batch of experiments. The results showed excellent flocculation performance with the weight ratio of alginic acid:NaHCO3 and CaCl2.2H2O at 1:0.3:0.02 and the dosage of flocculants at 0.0050 g/25 mL of phosphate solution in the range of initial phosphate concentration from 50 to 1000 ppm. Comparing to the sample without flocculants, the phosphate removal efficiency using CaO and Ca(OH)2 with the addition of flocculants increased from 19 and 20% to 97% at the initial phosphate concentration of 50 ppm, respectively by filtration of filter paper 2.7 μm.

The relationship between maritime phosphate pollution and socioeconomic wellbeing

Phosphate rock reserves are expected to deplete in the next 50-100 years, with the point of highest phosphorus production predicted to be in 2030. Phosphate, the base of many fertilizers, is a non-renewable resource. Ocean phosphate concentrations provide a good indication of global fertilizer use, since agricultural runoff often contributes to increases in ocean phosphate concentration. This study explores the relationship between the concentration of phosphate in a nation’s maritime borders and the nation’s score on the Social Progress Index. The study aims to link findings with possible approaches to help meet two of the United Nations’ (UN) Sustainable Development Goals: creating sustainable communities, and conserving and sustainably using oceans. Phosphate concentration data were acquired from the National Oceanic and Atmospheric Administration and compared with factors of social welfare from the 2018 Social Progress Index. For each nation on the Social Progress Index, the nation’s score on every factor was separately compared to ocean phosphate concentration data within that nation’s maritime borders, and a linear regression was performed for each comparison. The results indicate countries ranking higher on the Social Progress Index generally have greater ocean phosphate concentrations, suggesting that countries of higher social welfare contribute more to global phosphate use or have greater amounts of fertilizer runoff. The findings should be considered by developed nations to inform decisions around pollution reduction as well as developing nations aiming for sustainable social progress. Both should consider the environmental effects that social progress has or will have on the greater global community, of which the significance to sustainable resource development and environmental protection is invaluable.

Effect of electrode configuration and voltage variations on electrocoagulation process in phosphate removal of laundry wastewater

Indonesia is one of the countries that still have to deal with waste problems. In reducing waste, the government has made a series of efforts to reduce waste, especially wastewater. There are many kinds of wastewater. One of them is laundry wastewater. This research aims to estimate the dangerous substance in laundry wastewater and how to treat it. The method using some variables like Al-Al, Al-Fe, Fe-Fe, and Fe-Al and the voltage is changing from 20 V, 30 V, 40 V, and 60 V. The research shows that the most optimum result of laundry wastewater treatment was using Al-Fe electrode plate 60 V. The result that the phosphate concentration decreased by 6.56 mg/l from 9.58 mg/l to 3.01 mg/l and obtained phosphate removal efficiency of 68.56%. The most optimum results for the removal of phosphate levels contained in the 60 V voltage.

Phosphorus uptake by Oscillatoria sp. microalgae for bioavailability under anaerobic condition to predict eutrophication

Phosphorus is generally considered the limiting nutrient for algae growth in the aquatic environment. The phosphorus uptake for algae can give information for bioavailability-P. The contribution of phosphorous to bioavailability was evaluated using uptake-P in water solution under anaerobic conditions. The more is the incubation time, the more is the phosphate bioavailability. The maximum bioavailability occurred at 14 days with a phosphate concentration of 50 ppm resulting in P-available of 18.41 ppm. There was a linear correlation between P-available with P-medium with R2 = 0.97. The phosphorus bioavailability can be resulted from the equation: [P-Available] = 0.3789 x [P-medium]. The phosphate absorbed by the algae Oscillatoria sp in anaerobic conditions with initial concentrations of 10, 20, 30, 40 and 50 ppm was 5.46, 8.65, 11.63, 17.99 and 18.41 ppm, respectively. The maximum efficiency adsorption occurred in the concentration of 30 ppm with 49.18% adsorption.

HYBRID ANAEROBIC BAFFLED REACTOR FOR REMOVAL OF BOD AND PHOSPHATE CONCENTRATION IN DOMESTIC WASTEWATER

<span id="docs-internal-guid-e4ec4542-7fff-e572-3432-dc3c540a72ea"><span>Hybrid Anaerobic Baffled Reactor (HABR) is a development technology from the Anaerobic Baffled Reactor (ABR), which was already known as a technology that is successful in treating domestic waste. </span><span>Aims: </span><span>The objectives of these studies were to investigate the efficiency of reducing BOD and phosphate levels in HABR with zeolite (ZE) and activated carbon (AC) media. </span><span>Methodology and Results:</span><span> HABR reactor made of acrylic material with a size of 90 cm x 20 cm x 30 cm. The reactor designed has 7 compartments, with details the first 5 compartments are suspended growth microorganism reactors and the next 2 compartments are attached growth microorganism reactors. </span><span>Conclusion, significance, and impact of study:</span><span> The result of the research showed that the efficiency of reducing BOD concentration in the reactor with ZE and AC media were 59.30% and 65.12%, respectively. The final BOD concentration in the AC reactor is 30 mg/L, this value meets the domestic wastewater quality standard required by East Java Governor Regulation Number 72 of 2013 concerning Wastewater Quality Standards for Industry and/or Other Business Activities. The final BOD concentration in the ZE reactor exceeded the required quality standard with a value of 35 mg/L. The final phosphate levels of the two reactors meet the wastewater quality standards for business and/or laundry activities with a maximum phosphate concentration of 10 mg/L. The final phosphate levels in the ZE and AC reactors were 3.74 mg/L and 8.79 mg/L, respectively. The efficiency of phosphate removal in ZE and AC reactors were 70.58% and 30.87%, respectively.</span></span>

High Concentration Organic Wastewater with High Phosphorus Treatment by Facultative MBR

Phosphorus is one of the main factors causing water eutrophication, and the traditional phosphorus removal process causes phosphorus-rich sludge pollution. The facultative MBR process uses phosphate-reducing bacteria to convert phosphate into directly recyclable gaseous phosphine to solve this malpractice and make sewage become a new phosphorus resource. In order to investigate the phosphorus removal efficiency and the mechanism under facultative conditions, run the facultative MBR reactor for 30 days. The COD value, phosphate concentration, and phosphine yield were measured, and the changes of sludge metabolic pathway abundance and community composition in different periods were detected. According to the measurement, the maximum phosphorus removal efficiency is 43.11% and the maximum yield of phosphine is 320 μg/m3 (measured by the volume of sewage). Combined with thermodynamic analysis, the microbial mechanism of the reactor was proposed, and the possible transformation pathway of phosphorus was analyzed. At last, changes the phosphorus removal process from the ‘removal type’ to the ‘recycling type’.

Fixed-Bed Column Technique for the Removal of Phosphate from Water Using Leftover Coal

The excessive discharge of phosphate from anthropogenic activities is a primary cause for the eutrophication of aquatic habitats. Several methodologies have been tested for the removal of phosphate from aqueous solutions, and adsorption in a flow-through reactor is an effective mechanism to reduce the nutrient loading of water. This research aimed to investigate the adsorption potential of leftover coal material to remove phosphate from a solution by using continuous flow fixed-bed column, and analyzes the obtained breakthrough curves. A series of column tests were performed to determine the phosphorus breakthrough characteristics by varying operational design parameters such as adsorbent bed height (5 to 8 cm), influent phosphate concentration (10–25 mg/L), and influent flow rate (1–2 mL/min). The amorphous and crystalline property of leftover coal material was studied using XRD technology. The FT-IR spectrum confirmed the interaction of adsorption sites with phosphate ions. Breakthrough time decreased with increasing flow rate and influent phosphate concentration, but increased with increasing adsorbent bed height. Breakthrough-curve analysis showed that phosphate adsorption onto the leftover coal material was most effective at a flow rate of 1 mL/min, influent phosphate concentration of 25 mg/L, and at a bed height of 8 cm. The maximal total phosphate adsorbed onto the coal material’s surface was 243 mg/kg adsorbent. The Adams–Bohart model depicted the experimental breakthrough curve well, and overall performed better than the Thomas and Yoon–Nelson models did, with correlation values (R2) ranging from 0.92 to 0.98. Lastly, leftover coal could be used in the purification of phosphorus-laden water, and the Adams–Bohart model can be employed to design filter units at a technical scale.