Recovery of Phosphorus From Swine Manure by Ultrasound/H2O2 Digestion, Struvite Crystallization, and Ferric Oxide Hydrate/Biochar Adsorption

Abstract

Swine manure is potentially harmful to the environment but is also a readily accessible local source of phosphorus (P) for agricultural use. Decreasing the environmental impact of swine manure and recovering P from swine manure have been a challenge for a long time. In this study, an integrated process involving ultrasound/H2O2 digestion, struvite crystallization, and ferric oxide hydrate (HFO)/biochar adsorption was used to recover P from swine manure. The ultrasound/H2O2 treatment effectively solubilized the swine manure and converted organic P and other sparingly soluble P species into soluble phosphate. The struvite crystallization process allowed 85% of the available P to be recovered at pH 10.0 using a Mg:P molar ratio of 1.4 and a stirring rate of 150 rpm. HFO was loaded onto biochar synthesized by pyrolyzing ground corncob. The mechanism through which P was adsorbed was investigated by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The adsorption of P by the HFO/biochar followed pseudo-second-order kinetics and was primarily controlled by chemical processes. The maximum amounts of P adsorbed were 225.08–242.21 mg/g. Thermodynamic calculations indicated that the adsorption of P was endothermic and spontaneous and increased the degree of disorder in the overall system. P mass balance calculations indicated that 90.4% of the total P was recovered as struvite and P-saturated HFO/biochar.

Kinetics and morphological characteristics of struvite (MgNH4PO4.6H2O) under the influence of maleic acid

“…As can be seen, both the first period of precipitation (0-5 min) and the second (10-70 min) relatively fit the kinetic order selected, namely the first order. Attempts were made to fit for other kinetic models on struvite crystallization as reported by other researchers: pseudo-first order [4], pseudo-second order [4], and second order [21,34,35], but all resulting in a poorer match. The third order kinetic model was also tried [36] but with even worse results.…”

“…The formation of the K-doped struvite may be the result of KOH addition for pH adjustment, of which the K þ adsorbed/incorporated into the struvite. Values of pH in the range of 9.0-10.5 were reported to favor struvite-(K) precipitation during the phosphate and potassium recovery [4,18].…”

“…On the other hand, since ammonium and phosphate ions are essential for plant growth, struvite is considered potential as a fertilizer. In fact, recovery of Mg 2þ , NH 4 -N, and PO 4 ¡2 from wastewater as struvite has been an area of promising enterprise since the crystals produced are regarded as superior due to their slow-release nature [4,5,6]. Another important area of struvite research is the presence of this phosphate material as one of the major components of infectious urinary stones [7,8].…”

Studi Termodinamika Transpor Ionik Natrium Klorida Dalam Air dan Campuran Tertentu

“…Massa Molar (137)(138)(139) Penampilan Densitas (140)(141)(142) Titik Lebur (143)(144)(145) Titik Didih (146)(147)(148) Kelarutan (149)(150)(151) Dalam Air (152)(153)(154) 58,44 g/mol Massa [222][223][224][225][226]…”

Utilization of Bokashi Composting and Animal Feed Silage for Sustainable Agricultural Waste Management and Environmental Impact Analysis

“…Composting is an effective technology that transforms agricultural organic solid waste, such as manure, into fertilizers that are harmless to the environment (Awasthi et al, 2019;Yang et al, 2019). Other common agricultural waste treatments include anaerobic digestion (for bioenergy production) (Wang and Lee, 2021), thermochemical processes (for the production of high-value-added products) , and other integrated treatment pathways (Zhang et al, 2018). These methods provide opportunities to close the biogeochemical cycle of waste nutrients while controlling the public health risks posed by the increased production of organic waste .…”