Phosphorus sorption capacity of different types of opoka

Phosphorus sorption capacity of different types of opoka The bedrock opoka has been lately reported as an appropriate reactive media for onsite wastewater treatment systems due to its high phosphorus (P) sorption capacity. However, variations on its chemical composition may affect its reactivity with P, therefore leading to a variable P removal efficiency. In this paper, the P-sorption capacity of three different types of opoka from the region of Miechów, Poland, is reported. According to the silica and carbonate content, opoka samples were classified as light-weight and heavy-weight opoka. When heated over 900°C, opoka showed a very high P-sorption capacity that was well correlated to its Ca content. P-sorption isotherms from batch experiments with an artificial P solution were plotted and fitted to the Langmuir and Freundlich adsorption models. The Freundlich isotherm appeared to model better the P-sorption of light opoka and the Langmuir isotherm of heavy opoka, suggesting different dominating mechanisms of P-sorption by light and heavy opoka.

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Comparison of seven phosphorus sorption indices

Soil Research ◽

10.1071/sr9960081 ◽

1996 ◽

Vol 34 (1) ◽

pp. 81 ◽

Cited By ~ 28

Author(s):

MDA Bolland ◽

RJ Gilkes ◽

RF Brennan ◽

DG Allen

Keyword(s):

Sorption Capacity ◽

Buffer Capacity ◽

Sorption Isotherms ◽

Phosphorus Sorption ◽

P Sorption ◽

P Sorption Capacity ◽

Routine Procedures ◽

P Addition ◽

Western Australian ◽

Extractable Iron

Seven methods of estimating or predicting phosphorus (P) sorption capacity were compared for 47 neutral to acid Western Australian soils. Two methods, the P buffer capacity (PBC) and the Fox and Kamprath procedure, provided reliable indices of P sorption from well defined P sorption isotherms, but they are not quick routine methods because several levels of P addition are required. The other five routine procedures included two versions of the P retention index (PRI), determined by adding one level of P, and three soil properties, oxalate extractable iron (oxalate Fe), oxalate extractable aluminium (oxalate Al), and pH measured in sodium fluoride [pH (F)], that are known to indicate P sorption capacity. All the indices were well related to one another. The oxalate Fe index was the least well related to PBC whereas oxalate Al, one of the PRI indices, and pH (F) were closely related to PBC and could be used as quick, economical procedures to assess the P sorption capacity of soils.

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Phosphorus sorption and chemical characteristics of lightweight aggregates (LWA)-potential filter media in treatment wetlands

Water Science & Technology ◽

10.2166/wst.1997.0175 ◽

1997 ◽

Vol 35 (5) ◽

pp. 103-108 ◽

Cited By ~ 38

Author(s):

T. Zhu ◽

P. D. Jenssen ◽

T. Mæhlum ◽

T. Krogstad

Keyword(s):

Sorption Capacity ◽

Metal Content ◽

Exchange Capacity ◽

Chemical Characteristics ◽

Phosphorus Sorption ◽

Filter Media ◽

Total Metal Content ◽

P Sorption ◽

P Sorption Capacity ◽

Total Metal

Five light-weight aggregates (LWAs), suitable for filter media in subsurface flow constructed wetlands, were tested for potential removal of phosphorus (P). P-sorption variation is dependent on the chemical characteristics of the LWA. All LWAs exhibited high pH and high total metal content; however, P-sorption capacity varied by two orders of magnitude. Of the LWAs' chemical characteristics (total metal content, cation exchange capacity, and oxalate soluble Fe and Al), total metal content has the closest relationship with the P-sorption capacity. Among the four major metal ions (Mg, Ca, Fe and Al), Ca has the strongest correlation with the P-sorption capacity.

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Evaluation of phosphate sorption capacity and external phosphorus requirement of some agricultural soils of the southwestern Ethiopian highlands

Sains Tanah - Journal of Soil Science and Agroclimatology ◽

10.20961/stjssa.v18i2.51325 ◽

2021 ◽

Vol 18 (2) ◽

pp. 136

Author(s):

Berhanu Dinssa ◽

Eyasu Elias

Keyword(s):

Sorption Capacity ◽

Crop Production ◽

Agricultural Soils ◽

Soil Characteristics ◽

Soil Samples ◽

Phosphorus Sorption ◽

Acidic Soils ◽

Ethiopian Highlands ◽

P Sorption ◽

P Sorption Capacity

One of the most soil fertility management problems for crop production on acidic soils of the Ethiopian highlands is phosphorus fixation. The research was executed to assess the P-sorption capacity and to determine the external P requirement of different acidic soils in the Southwestern highlands of Ethiopia. Phosphorus sorption capacity (Kf) and its relation with selected soil characteristics were assessed for some major agricultural soils in the Ethiopian highlands to answer the questions, ‘What are the amount of P-sorption capacity and external P requirement of Nitisols, Luvisols, Alisols, and Andosols in Ethiopia?’. Twelve surface soil samples (at depth of 0-30 cm) were gathered and the P-sorption capacity was estimated. Phosphorus-sorption data were obtained by equilibrating 1 g of the 12 soil samples with 25 ml of KH2PO4 in 0.01 M CaCl2, having 0, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, and 330 mg P L-1 for 24 hours. The data were adjusted to the Freundlich adsorption model and the relationship among P-sorption and soil characteristics was established by correlation analysis. Clay content and exchangeable acidity, organic matter, Al2O3, and Fe2O3 oxides have affected phosphorus-sorption at a significance level of (P < 0.05). Alisols had the highest Kf value (413 mg kg-1) but Nitisols had the lowest Kf (280 mg kg-1). The external phosphorus fertilizer requirement of the soils was in the order of 25, 30, 32, and 26 mg P kg-1 for Nitisols, Luvisols, Alisols, and Andosols sequentially. The Kf varies among different soil types of the study area. The magnitude of the soil’s Kf was affected by the pH of the soil, soil OM content, and oxides of Fe and Al. Therefore, knowledge of the soils’ P retention capacity is highly crucial to determine the correct rate of P fertilizer for crop production.

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