A novel peat-based biosorbent for the removal of phosphate from synthetic and real wastewater and possible utilization of spent sorbent in land application

Abstract

Removal of potentially harmful phosphorus compounds from wastewater by adsorption onto biosorbents is a cost-effective alternative to the conventional treatment methods. Raw peat and peat modified with iron(III) hydroxy ions were used in this study to remove phosphate ions from synthetic solution and household wastewater. Interaction of iron(III) ions with carboxylic groups of peat occurred during peat modification, which was confirmed by the FTIR technique. The effect of the initial phosphate concentration, pH, contact time, temperature, and ionic strength was studied in batch experiments. It was found that the sorption capacity increased with the increasing temperature, i.e. the maximum sorption capacity of the modified peat was 9.64 mg P/g at 2˚C and 11.53 mg P/g at 40˚C, respectively, indicating the endothermic nature of the sorption. Besides, the Langmuir equation was used to describe the sorption isotherms quantitatively. Given that the spent biosorbent did not exhibit phytotoxicity and the concentration of heavy metals did not exceed the limit values, the phosphate-saturated modified peat may be utilized as an organic fertilizer in agricultural land application.

Removal of Pollutants from Wastewater using Organic Materials

“…Generally, it can be noticed that the organic material sawdust is more effective in removing the pollutants from agricultural and industrial wastewaters compared to other organic material compost as (Robalds, et al, 2016).…”

Directions for the Rational Use of Additional Organic and Mineral Resources of Peat Deposits

“…When carrying out activities related to the protection of the environment from the negative anthropogenic impact, it is proposed to use granular (usually spherical) composite sorbents [19]. Physico-chemical models reflecting the processes of sorption [20][21][22][23] suggest that the change of the characteristics of materials can be performed in two directions: varying the porous structure of the material and (or) regulating the physico-chemical and chemical properties of the reacting sorbent surface. The second group may include transformation of ion-exchange properties of the peat matrix [19].…”

“…The analysis of scientific sources [19][20][21][22][23] shows that the characteristics of peat sorbents for oil products removal allow them to successfully compete with other types of materials, having comparable values of absorption capacity and advantages in economic and ecological indicators. In addition, peat products are distinguished by a high degree of purification, ease of recycling and the possibility of producing selective sorbents, as well as the ability to remain on the water surface for a long time (more than one month).…”

Adsorption Using Lime-Iron Sludge–Encapsulated Calcium Alginate Beads for Phosphate Recovery with ANN- and RSM-Optimized Encapsulation

“…15/147,437 (2014)], alginate is biodegradable, and so phosphate saturated beads can be used directly as fertilizer, without the need to desorb or extract the phosphate. Robalds et al (2016) highlighted the importance of ensuring that the concentrations of heavy metals are within safe limits if the spent adsorbent is to be used for land application. Elemental analysis before and after adsorption did not indicate the presence of heavy metals and therefore underscores its potential for agricultural applications.…”