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Removal of high fluoride contents from aqueous solutions by inexpensive, and biocompatible biosorbent is a main concern for human health. In the present study the efficacy of Rhizopus oryzae fungal biomass in removal of fluoride from aqueous solutions considering the effects of different parameters such as contact time (10–180 min), initial fluoride concentration (2–10 mg/L), and biosorbent dose (0.25–2 g/L) was studied in a batch system. The optimum condition for the maximum fluoride biosorption (90.5%) was obtained at 2 g/L biosorbent dose, 30 min contact time and 2 mg/L initial fluoride concentration. The Langmuir model (R2 = 0.9844) fitted better than the other models and showed a homogeneous biosorption surface with the possibility of a monolayer biosorption of fluoride by biosorbent. The Langmuir maximum biosorption capacity of fluoride for R. oryzae was obtained at 1.16 mg/g. The biosorption kinetic was controlled by the pseudo‐second‐order (R2 = 0.9999) model and based on the intra‐particle diffusion model; the fluoride biosorption rate was not controlled only by the mechanisms of intra‐particle diffusion. Consequently, the results showed that fungal biomass can be used as a suitable biosorbent for fluoride removal from aqueous solutions. [ABSTRACT FROM AUTHOR]

This study was designed to present a facile and effective biosorbent from Prosopis cineraria and Syzygium cumini leave (PCL and SCL) for fluoride removal. The test was done in batch mode and the effect of contact time (5, 25, 60, 90, and 120 min), initial fluoride concentration level (3, 5, 8, and 12 mg/L), and biosorbent dose (1, 3, 5, 10, and 25 g/L) on the biosorption process were examined. The optimum conditions for the maximum fluoride removal were occurred at 1 g/L biosorbent dose and contact time of 120 (for PCL) and 90 min (for SCL). The results suggested that the pseudo‐second‐order and Langmuir isotherm models described the experimental data well. According to the Langmuir model, the maximum adsorption capacity of fluoride for PCL and SCL was attained 11.52 and 7.4 mg/g, respectively. Based on Boyd and intra‐diffusion models, the biosorption of fluoride onto PCL and SCL was mainly controlled by film‐diffusion. The study revealed the potential use of PCL and SCL as two new effective biosorbents for the removal of fluoride from aqueous solution. © 2019 American Institute of Chemical Engineers Environ Prog, 38: S429–S440, 2019 [ABSTRACT FROM AUTHOR]

Biosorption is considered to be one of the favorite treatment technologies for fluoride ion (F) removal from aqueous solutions. The purpose of this study was to measure the efficiency of Ziziphus leaf in the removal of F from aqueous solutions. The biosorption experiments were performed in batch systems at room temperature. The experimental parameters studied were: (i) the initial F concentration level (3-12 mg/L), (ii) the biosorbent dose (1-10 g/L), and (iii) the contact time (5-120 min). The highest removal biosorption of 100% was observed at a biosorbent dose of 10 g/L, a contact time of 90 min, and an initial F concentration level of 12 mg/L. At an initial F concentration of 12 mg/L, the most effective and applicable biosorbent dose was 5 g/L which resulted in the removal of 95.36% of the F after 25 min with a resulting F concentration of 0.55 mg/L, which is safe for drinking water. The Langmuir model fitted better than the Frendlich model and showed a homogeneous biosorption surface with the possibility of a monolayer biosorption of F by the biosorbent. The biosorption kinetic was controlled by the pseudo-first-order model. The results showed that Ziziphus leaf can be used as an environmentally friendly, cost effective, and effective biosorbent for the removal of F from aqueous solutions. [ABSTRACT FROM AUTHOR]

Disinfection byproducts (DBPs) in drinking water are important due to the probable risks they pose to human health. In this study, drinking water samples were collected from ' ' points from water transmission lines to the distribution system as well as district municipal demineralization plant (DMDP) for the first time in Bushehr from October 2015 to May 2 0 ' 6 for haloacetic acids (HAA5) analysis by using a GC-ECD. The effects of pH, temperature, chlorine dosage, UV-254, TOC, SUVA, different water sources, seasonal and spatial variations were evaluated and the concentration level of HAA5 was compared with drinking water guideline. The results revealed that the monochloroacetic acid and monobromoacetic acid were the major haloacetic acids found in all water samples, which accounted for 42.65 and 47.03% of HAA5, respectively. HAA5 concentration levels in almost 40.9% of the samples were higher than the maximum contaminant level (MCL) contents set by Environmental Protection Agency (EPA). Significant correlation was observed between monobromoacetic acid concentration level with pH and temperature, as well as dichloroacetic acid concentration level with UV-254. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine adsorption properties of cuttlebone, cuttlefish bone as dead biomass, for lead(II) and copper(II) from aqueous solutions. Adsorption kinetic, isotherm and effect of pH (in the range of 2.0-7.0) were investigated in a single component batch system at room temperature (25 ±1 °C). The heavy metal adsorption by cuttlebone was relatively rapid and reached equilibrium in 120 min in all the cases. The pseudo-second order rate equation described the adsorption kinetic of both the ions. The adsorption capacities of Pb2+ and Cu2+ were constantly increased by pH and the optimum condition of pH was determined to be 7.0. The Freundlich model was better fitted than other models with the isotherm data, indicating sorption of the metal ions in a heterogeneous surface. According to the Langmuir model, the maximum adsorption capacities of cuttlebone for Pb2+ and Cu2+ were determined to be 45.9 and 39.9 mg/g, respectively. The results indicated cuttlebone as a promising adsorbent for Pb2+ and Cu2+, which presents a high capacity of self-purification in marine environments and also can be used for removal of the metal ions from water and wastewater. [ABSTRACT FROM AUTHOR]

Biosorption is considered to be one of the favored treatment technologies for fluoride ion (F) removal from aqueous solutions. The aim of this study was to determine the efficiency of cuttlebone (cuttlefish bone) obtained from the Persian Gulf in the removal of F from aqueous solutions. The biosorption experiments were studied in batch systems at room temperature. The effects of experimental parameters biosorbent dose, contact time, pH, and initial F concentration were studied. The highest removal biosorption was observed at 100 g/ L of biosorbent, at 120 min contact time and an initial F concentration at 12 mg/L (88.52%). The Langmuir model fitted better than the Frendlich model and showed a homogeneous biosorption surface with the possibility of a monolayer biosorption of F by the biosorbent. The biosorption kinetic was controlled by the pseudo-second order and pore diffusion models. The results showed that cuttlebone can be used as an environmentally friendly, cheap, and effective biosorbent of F from aqueous solutions, particularly in the coastal areas of the Persian Gulf with high-F levels in the drinking water. [ABSTRACT FROM AUTHOR]

The fluoride ion (F) concentration levels of the 20 most popular herbal distillates sold in Iran were determined. The mean F content of the samples was 50 μg/L with a range of not detectable-340 μg/L. The estimated maximum daily, weekly, and monthly intakes of F were 34, 238, and 1020 μg/day respectively. The results of this study showed that the low concentration levels of F found in Persian herbal distillates should not normally significantly increase the F intake of consumers. [ABSTRACT FROM AUTHOR]

Adsorption is considered as the most promising treatment technology for fluoride (F) removal from aqueous solutions. The aim of this study was to determine the efficiency of seed Moringa oleifera ash in removal of F from aqueous solutions. After determining optimum pH (pH=7) and ashing temperature (650° C) by pretests, the adsorption experiments were studied in batch systems at room temperature. The effects of experimental parameters such as adsorbent dose (0.8 - 64 g/1), contact time (5 -120 min) and initial F concentration (2 -8 mg/1) were studied. The highest removal adsorption was at 64 g/1 adsorbent, 10 min contact time and initial F concentration at 8 mg/1 (81.14% F removal). The results showed that the Moringa Oleifera ash can be used as an environmental friendly, cheap and effective adsorbent from aqueous solutions. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the efficiency of shrimp shell waste for the removal of fluoride (F) from aqueous solutions by adsorption, the most promising treatment technology for this purpose. In a series of batch experiments at room temperature, the experimental parameters studied were: initial adsorbent dose (3.2-64 g/L), initial F concentration (2-8 mg/L) while the mass ratio of biosorbant dose (g/L) to initial F concentration (mg/L) was fixed at 5 ratios in the range 400-8000, contact time (5-120 min), pH (3-11), and the presence of competing anions (bicarbonate, nitrate, carbonate, sulfate, and chloride at 200-400 mg/L). We concluded that shrimp shell waste can be a cheap, effective, and environmentally friendly adsorbent of F from aqueous solutions. [ABSTRACT FROM AUTHOR]