Boron removal from seawater reverse osmosis permeate utilizing selective ion exchange resin

Boron removal from aqueous solution by reverse osmosis

Boron is present in the form of boric acid (B(OH)3 or H3BO3) in seawater, geothermal waters, and some industrial wastewaters but is toxic at elevated concentrations to both plants and humans. Effective removal of boron from solutions at circumneutral pH by existing technologies such as reverse osmosis is constrained by high energy consumption and low removal efficiency. In this work, we present an asymmetric, membrane-containing flow-by electrosorption system for boron removal. Upon charging, the catholyte pH rapidly increases to above ∼10.7 as a result of water electrolysis and other Faradaic reactions with resultant deprotonation of boric acid to form B(OH)4- and subsequent removal from solution by electrosorption to the anode. Results also show that the asymmetric flow-by electrosorption system is capable of treating feed streams with high concentrations of boron and RO permeate containing multiple competing ionic species. On the basis of the experimental results obtained, a mathematical model has been developed that adequately describes the kinetics and mechanism of boron removal by the asymmetric electrosorption system. Overall, this study not only provides new insights into boron removal mechanisms by electrosorption but also opens up a new pathway to eliminate amphoteric pollutants from contaminated source waters.

For plants and animals, boron is an essential micronutrient. However, it is harmful and poisonous in high doses. So, in that study it was aimed to conduct studies to remove boron from the wastewater of Eti Mine Works using natural and modified adsorbents. Firstly, adsorption studies were carried out with the wastewater taken from Emet Boron Operations Directorate with waste clays obtained from Emet, Bandırma, Kırka, Bigadiç Operations Directorates and zeolite obtained from site of the Bigadiç Operations Directorate in a batch system of shaking, thermostat water bath. Modified walnut shells and modified waste corn cobs also with modified waste sunflower stems were used as adsorbents in different studies. Adsorption studies were carried out using different amount of adsorbent, pH and particle size to determine the effects of these parameters on adsorption. The adsorption processes were found to be insufficient to remove boron from wastewater with high boron content as 5883 ppm using natural adsorbents. For this reason, it was thought that it would be more appropriate to remove some of the boron in the wastewater by chemical precipitation with lime as a preliminary process, then to conduct adsorption studies with environmentally friendly natural adsorbents. Secondly, it was aimed to eliminate high boron content in Espey Spring Water with high boron content in the Espey Open Pit Site to improve the quality of irrigation water within the framework of social responsibility. Espey Spring Water’s initial boron value was 3810 ppm. After two-stage pre-treatment with lime, its boron value was 297 ppm (92% removal efficiency). Then, the adsorption studies were carried out at the same conditions as in the first part of this study using HCl modified almond shells as adsorbent. The optimum parameters reached were as 8 g of adsorbent, at pH 10, at 150 rpm mixing speed, at 25 ºC and at 4 hours contact time. And in the adsorption process consisting all these optimum parameters; 66,7% removal efficiency was reached. Almond shells were found to be effective adsorbents for boron removal from springs waters, having high boron content in the scope of social responsibility considering environment and living health. This result was important from economic perspective also, because of evaluating natural wastes, as almond shells, in the adsorption process for boron removal.

Sustainable treatment of boron industry wastewater with precipitation-adsorption hybrid process and recovery of boron species

Low-cost materials for boron removal need to be developed to reduce the overall cost of treatment of boron-containing wastewater. In this paper, the preparation of a boron removal material using waste concrete particles is described. With high initial boron concentrations (100 and 300 mg/L boron), the removal performance was insufficient and the dominant boron removal mechanism was estimated to be precipitation of calcium borate. With a low initial boron concentration (10 mg/L boron), more boron was removed by increasing the amount of the sorbent, and the boron removal can be attributed to ion exchange. After heat treatment of the material at 175 °C, an initial decrease in the boron removal rates was observed, but after 1440 min the residual boron concentrations for the heat-treated material were much lower than those for the untreated material. This improvement is thought to be due to the generation of metaettringite, the dehydration product of ettringite.

Effect of operating parameters on removal of boron from wastewater containing high boron concentration by vacuum assisted air gap membrane distillation

Batch and column mode tests were carried out to evaluate the efficiency of boron and arsenic removal from geothermal water in Kyushu Island, Japan by an ion exchange method. The geothermal water contained 34.0 mg-B/L and 3.23 mg-As/L. The sorption tests were performed using boron selective ion exchange resins (Lewatit MK 51 and Diaion CRB 03) and arsenic selective ion exchange resins (Lewatit FO 36, ArsenXnp). The optimum concentration of resin for boron removal from geothermal water was determined as 5.0 g/L-geothermal water for both Lewatit MK 51 and Diaion CRB 03 resins. On the other hand, Diaion CRB 03 performed better than Lewatit MK 51 during the column-mode study. For arsenic removal, the optimum resin amount was found as 6.0 g/L-geothermal water for both Lewatit FO 36 and ArsenXnp resins. It was observed that Lewatit FO 36 was more effective than ArsenXnp for the removal of As from geothermal water.

Although, boron (B) is an essential micronutrient for plants, animals and human beings; at high concentration of boron in water resources may be hazardous for living being. Hence the boron concentration has to be reduced down to suggested level by the World Health Organization for safe use of water for irrigation and drinking. The present study examines boron pollution level in groundwater and suggests an alternative sorbent to remove it from water sources used for irrigation and drinking. The poly-2-Hydroxyethyl methacrylate (HEMA)-co- glycidyl methacrylate (GMA)- polyethyleneimine (PEI)- Fe3+ columns were synthesized to adsorb the boron compounds from a real groundwater samples and synthetic solution. Boron was removed 78.2% by poly (HEMA-co-GMA)-PEI- Fe3+ column at an amount of 54.42 mg/g, pH 8. However, the lower adsorption ratio was recorded as between 35.8–58.1% of real groundwater where adsorbed amount of boron and its derivates were found as 9–28.67 mg/g due to other chemical ions in real groundwater samples. Boron-loaded columns were regenerated by 0.01 M NaOH treatment for industrial practice. Regeneration cycles were performed successfully 15-times with only a loss of 5% in adsorption capacity of columns.

Geothermal energy is an alternative renewable energy resource that has proven itself technically and economically feasible as a nonpollulanl electric power source. The Denizli-Kizildere geothermal energy region is the first major geothermal energy resource project in Turkey, with an estimated potential of 200 MW. The use of the geothermal potential of the region depends on removal of its high boron content, since waste brine is discharged into the nearby Bilyuk Menderes River. This article represents a study for removing boron from Kizildere / Turkey geothermal wastewater using the boron selective resin Amberlite FRA-743. The effect of regenerant type and regeneration conditions has been investigated to find the optimal operational conditions for minimizing the regenerant consumption.

Efficient boron removal from irrigation waters is crucial for sustainable agriculture, as elevated levels of boron can be toxic to many plants, limiting growth and crop productivity. In this context, the present study investigated the sorption equilibrium of boron using zeolites in two types of aqueous matrices: a synthetic solution containing only boron and natural irrigation waters. Through the application of various isothermal sorption models (Langmuir, Freundlich, Sips, Toth, Jovanovic, Temkin, Dubinin-Radushkevich, and Redlich-Peterson), the efficacy of zeolite for boron removal under controlled and real conditions was evaluated. The results indicated a notable difference in sorption behavior between the two matrices, reflecting the complexity and heterogeneity of interactions in the boron-zeolite system. In the synthetic solution, the Freundlich model provided the best fit (R2 = 0.9917), suggesting heterogeneous and multilayer sorption, while the Sips model showed high efficacy in describing the sorption in both matrices, evidencing its capability to capture the complex nature of the interaction between boron and zeolite under different environmental conditions. However, in natural irrigation waters, the Jovanovic model demonstrated the most accurate fit (R2 = 0.999), highlighting the importance of physical interactions in boron sorption. These findings underscore the significant influence of the water matrix on the efficacy of zeolite as a boron removal agent, emphasizing the need to consider the specific composition of irrigation water in the design of removal treatments. Additionally, the results stress the importance of selecting the appropriate isothermal model to predict boron sorption behavior, which is crucial for developing effective and sustainable treatment strategies. This study provides a basis for optimizing boron removal in various agricultural and industrial applications, contributing to the design of more efficient and specific water treatment processes.

Reclamation of RO permeate and concentrate of geothermal water by new chelating resins having N-methyl-D-glucamine ligands

Utilization of geothermal water as irrigation water after boron removal by monodisperse nanoporous polymers containing NMDG in sorption–ultrafiltration hybrid process

Constructed wetlands (CW) are being explored as an alternative treatment for boron removal. The efficiency of CW strongly depends on the substrate and plants used. A promising and inexpensive substrate is rice husk. This study explored the capacity of this residue to treat boron-rich wastewaters as main wetland substrate in laboratory constructed wetland microcosms. Two plants, Typha angustifolia and Puccinellia frigida, were used to evaluate their capacity to increase boron removal. It was found that CW removed ~40% of boron. Although both species presented high boron concentrations in their shoots (between 463 and 721 mg/kg), they did not enhance its removal. Interestingly, high sulfate removal was also observed, especially in non-vegetated cells (up to 68±18%), indicating that the presence of plants decreased their removal. Processes involved are probably biotic sulfate reduction and abiotic precipitation of sulfate minerals (hypothesis supported by PHREEQC modeling). Therefore, the performance of the system under continuous flow operation for a boron-and sulfate-rich wastewater indicates that rice husk has high potential as main media in CW for boron and sulfate removal.

Theoretical and experimental investigation of boron rejection by forward osmosis membrane

Removal of boron and iodine from optoelectronic wastewater using Mg–Al (NO 3) layered double hydroxide