Phosphate and Ammonium Removal from Wastewaters Using Natural-Based Innovative Bentonites Impacting on Resource Recovery and Circular Economy

The research objective of the study is the estimation of a novel low-cost composite material f-MB (Fe-modified bentonite) as a P and N adsorbent from wastewaters. Τhe present study aimed at examining the phosphate and ammonium removal efficiency from different types of wastewater using f-MB, by conducting bench-scale batch experiments to investigate its equilibrium characteristics and kinetics. The SEM analysis revealed that the platelets of bentonite in f-MB do not form normal bentonite sheets, but they have been restructured in a more compact formation with a great porosity. Regarding the sorption efficiencies (Qm), the maximum phosphate sorption efficiencies (Qm) calculated using the Langmuir model were 24.54, 25.09, 26.13, 24.28, and 23.21 mg/g, respectively, for a pH range of 5 to 9. In addition, the maximum NH4+-N adsorption capacities (Qm) calculated from the Langmuir model were 131.8, 145.7, 168.5, 156.7, and 159.6 mg/g, respectively, for a pH range from 5 to 9. Another important finding of this study is that f-MB can recover P from treated wastewater impacting on resource recovery and circular economy (CE). The modified clay f-MB performed the phosphate and ammonium recovery rates of 80% and 78.5%, respectively. Finally, f-MB can slowly release the largest proportion of phosphate and ammonium ions for a long time, thus extending the application of the f-MB material as a slow-release fertilizer and soil improver.

Removing Ammonium From Contaminated Water Using Purolite C100E: Batch, Column, and Household Filter Studies

Ammonium removal from drinking water to protect human and environmental health is one of the major global concerns. This study evaluates the performance of Purolite C100E, a commercial cation exchange resin, on eliminating ammonium in synthetic and real contaminated groundwater. The results demonstrate that the pH operation range of the resin for better ammonium removal is 3 to 8, while the optimum contact time was about 30 min. The kinetics of the ammonium removal process followed both the Pseudo-first order and Pseudo-second order models. Equilibrium data of ammonium removal fitted both the Langmuir and Freundlich isotherm models with the maximum Langmuir ion exchange capacities for initial ammonium concentrations of 10-200 mg/L and 50-2000 mg/L reaching 18.37 mg/g and 40.16 mg/g, respectively. The presence of co-ions in the water reduced the ammonium removal efficiencies in the order Mg2+> Ca2+> K+. The maximum exchange capacity in the fluidised bed studies of the original Purolite C100E (bed height 27 cm, resin weight 75 g, initial ammonium concentration 17.4 mg/L, filtration velocity 0.5 m/h) was 10.48 mg/g. It progressively reduced slightly after three regeneration cycles to 8.79 mg/g. The column breakthrough data satisfactorily fitted the Thomas model. A household filter cartridge packed with 4 kg Purolite C100E (80 cm height) and operated at a filtration velocity of 1.9 m/h in Vietnam successfully reduced the initial 6 mg NH4+/L in groundwater (after sand filter pre-treatment) to well below the Vietnam drinking water standard (3 mg/L) continuously for one week.

Iron-reducing - and -proteobacteria isolated from laboratory-scaled heterotrophic feammox bioreactor

Ammonium removal from wastewater is a crucial step in wastewater treatment. Presently employed technologies based on nitrification/denitrification and partial nitritation/anammox principles require oxygen for the nitrification step, and are therefore still not yet fully satisfied with the application practice. In recent years, biological ammonium oxidation coupled with ferric iron reduction (feammox) has been proposed to be responsible for the nitrogen loss in different ecological habitats. Related to the wastewater aspect, the feammox principle has been discussed as an alternative approach for ammonium removal without dependency on oxygen. From a laboratory-scaled feammox bioreactor operated under neutral pH, two bacterial strains FN7 and FN9 were isolated by using the anaerobic Hungate technique. Comparative analyses of 16S rDNA sequences showed that these strains were most closely related to the b-proteobacterium Aciclyphilus denitrificans and the g-proteobacterium Pseudomonas stutzeri, respectively. Although being phylogenetically apart, strains FN7 and FN9 shared several common physiological characteristics that are considered meaningful for the feammox process, i.e. (i) heteroptrophic ammonium oxidation, (ii) denitrification, and (iii) ferric iron reduction. These isolates are proposed to play certain roles in the studied feammox system, contributing to the ammonium removal under heterotrophic feammox condition. The 16S rDNA sequences of strains FN7 and FN9 were available in GenBank under the accession numbers LC474369 and MT568614, respectively.

Lampiran 5A paper Removal of nitrate, ammonia and phosphate from aqueous solutions in packed bed filterusing biochar augmented sand media

Nutrients from wastewater are a major source of pollution because they can cause significant impact on the ecosystem. Accordingly, it is important that the nutrient concentrations are kept to admissible levels to the receiving environment. Often regulatory limits are set on the maximum allowable concentrations in the effluent. Therefore, wastewater must be treated to meet safe levels of discharge. In this study, laboratory investigation of the efficiency of packed bed filters to remove nitrate, ammonium and phosphate from aqueous solutions were conducted. Sand and sand augmented with hydrochloric acid treated biochar (SBC) were used as packing media. Synthetic wastewater solution was prepared with PO43-, NO3-, NH4+ concentrations 20, 10, 50 mg/L, respectively. Each experiment ran for a period of five days; samples from the effluent were collected on alternate days. All experiments were duplicated. Over the experiment period, the average removal efficiency of PO43-, NO3-, NH4+ were 99.2%, 72.9%, 96.7% in the sand packed columns and 99.2%, 82.3%, 97.4% in the SBC packed columns, respectively. Although, the presence of biochar in the packing media had little effect on phosphate and ammonium removal, it significantly improved nitrate removal