Effects of Lanthanum Modified Bentonite and Polyaluminium Chloride on the Environmental Variables in the Water and Sediment Phosphorus Form in Lake Yanglan, China

The application of lanthanum modified bentonite (Phoslock®) and polyaluminium chloride (PAC) is popular in the restoration of European temperate lakes; however, the effects of the application on the concentrations of phosphorus (P) in both the water and the sediments have been poorly evaluated to date. We studied the effects of the application of Phoslock® + PAC on the concentrations of total phosphorus (TP), particulate phosphorus (PP), soluble reactive phosphorus (SRP), total suspended solids (TSS) and chlorophyll a (Chla) in the water, and different P forms in the sediments, in an isolated part of Lake Yanglan. The results showed that the concentrations of TP, PP, SRP, TSS and Chla decreased significantly after the addition of Phoslock® + PAC. Moreover, the concentrations of labile-P, reductant-soluble-P and organic-P in the sediments were also significantly decreased after the Phoslock® + PAC application. However, the concentrations of both the stable apatite-P and residual-P in the sediments after application of Phoslock® + PAC were much higher than the pre-addition values, while the concentrations of metal-oxide-P did not differ significantly between the pre- and post- application conditions. Our findings imply that the combined application of Phoslock® and PAC can be used in the restoration of subtropical shallow lakes, to reduce the concentrations of P in the water and suppress the release of P from the sediments.

Spatial distribution of water-mobilizable colloids and phosphorus from dam reservoir sediment

<p>The hydrodynamics of dam reservoirs favor the accumulation of phosphorus (P) in bottom sediments since it has a strong affinity for the sedimentary particles. However mechanical disturbance of sediment (resuspension) may release P back to water column. The load of sedimentary P poses a serious ecological problem related to the maintaining of water eutrophication. The aim of this study was to evaluate the potential of sediments, accumulated in Champsanglard reservoir (Central France), to release water-mobilizable colloidal and dissolved P. A sampling campaign was carried out at different locations along the main channel of reservoir from riverine to lacustrine area and characterized by different hydrodynamics. The results showed that colloids are intrinsic component of reservoir sediment and contribute up to 2.3% of sediment mass. Colloidal P attributed up to 6% of total sedimentary P and 80% of water-mobilizable P (fraction < 1 µm). The stock of water-mobilizable colloids and associated P varied according to particle size distribution and was strongly dependent to channel morphology, hydrodynamics and inlet of tributary.</p><p><strong>Keywords: </strong>Dam reservoir, sedimentary colloids, phosphorus form, spatial variability</p>

Effect of drill cuttings addition on physicochemical and chemical properties of soil and red clover (Trifolium pretense L.) growth

The most economical method of drill cuttings disposal may be their application in land reclamation which allows for the wastes recovery. However, the wastes application into the soil should ensure that the quality of the environment would not be deteriorated. These investigations were aimed at identifying the effect of drill cuttings, which were the mixture of different types of drilling wastes, on the physicochemical properties of acidic soil and growth of red clover (Trifolium pratense L.). The experimental design comprised 5 treatments, which differed in a dose of the drill cuttings: 0% (control), 2.5%, 5%, 10% and 15% of dry weight. A six-week pot experiment was conducted to determine the influence of the wastes on the plant growth. The results showed that the drill cuttings addition significantly changed the chemical and physicochemical properties of the soil, such as: electrical conductivity (EC), pH, base saturation, content of carbonate, alkaline cations (Ca2+, Na+, K+, Mg2+), organic matter, total organic carbon (TOC), and available phosphorus form. However, the most important factors that influenced the growth of red clover were pH, base saturation, content of Mg2+ and plant available phosphorus. The red clover biomass was increased from 1.5 to 2.5 times depending on the dose of wastes. We concluded that the examined wastes can be used for reclamation of the acid and unfertile degraded soils, but the amount of wastes should not exceed 5% of the soil, because the highest total clover biomass was observed just at this dose.

Edge-of-Field Technologies for Phosphorus Retention from Agricultural Drainage Discharge

Agriculture is often responsible for the eutrophication of surface waters due to the loss of phosphorus—a normally limiting nutrient in freshwater ecosystems. Tile-drained agricultural catchments tend to increase this problem by accelerating the transport of phosphorus through subsurface drains both in dissolved (reactive and organic phosphorus) and particulate (particle-bound phosphorus) forms. The reduction of excess phosphorus loads from agricultural catchments prior to reaching downstream surface waters is therefore necessary. Edge-of-field technologies have been investigated, developed and implemented in areas with excess phosphorus losses to receive and treat the drainage discharge, when measures at the farm-scale are not able to sufficiently reduce the loads. The implementation of these technologies shall base on the phosphorus dynamics of specific catchments (e.g., phosphorus load and dominant phosphorus form) in order to ensure that local retention goals are met. Widely accepted technologies include constructed wetlands, restored wetlands, vegetated buffer strips and filter materials. These have demonstrated a large variability in the retention of phosphorus, and results from the literature can help targeting specific catchment conditions with suitable technologies. This review provides a comprehensive analysis of the currently used edge-of-field technologies for phosphorus retention in tile-drained catchments, with great focus on performance, application and limitations.

Distribution of P2O5 between P-rich Phase and Matrix Phase in P-bearing Steelmaking Slag

To recycle the phosphorus in P-bearing steelmaking slag and use the slag as phosphate fertilizer, it is necessary to study the distribution of P2O5 between the P-rich phase and matrix phase in P-bearing steelmaking slag. The addition of MgO and MnO into the slag has no effect on the phosphorus form of existence in the slag and has little effect on the %(P2O5)SS. In contrast, Na2O and CaF2 in the slag change the phosphorus form of existence in the slag and increase %(P2O5)SS obviously. Lp’, ${\gamma _{{{\rm{P}}_2}{{\rm{O}}_5}(SS)}}$, ${\gamma _{{{\rm{P}}_2}{{\rm{O}}_5}(M)}}$, CP(M) and CP(SS) were calculated, and it was found that %(CaO), %(T.Fe) and %(P2O5) in the P-rich phase and matrix phase significantly affect Lp’. MnO and MgO in the slag have little effect on the distribution of P2O5 between the P-rich phase and matrix phase, whereas Na2O and CaF2 affect the distribution of P2O5 between the P-rich phase and matrix phase.

Kajian Fraksionasi Fosfor (P) Pada Beberapa Pola Penggunaan Lahan Kering Ultisol di Desa Jalin Jantho Aceh Besar

Abstrak. Penelitian ini bertujuan untuk mengetahui komposisi fraksi fosfor (P) pada beberapa pola penggunaan lahan kering Ultisol di Desa Jalin Jantho Aceh Besar. Penelitian ini menggunakan metode deskriptif yang didasarkan pada pengamatan ciri - ciri tanah dilapangan dan analisis tanah di laboratorium. Hasil analisis penelitian menunjukkan bahwa kandungan P-tersedia tanah paling tinggi di jumpai pada penggunaan lahan sawah lapisan permukaan (1,6 ppm), Kandungan P-total tertinggi dijumpai pada penggunaan lahan hutan sekunder lapisan bawah permukaan (76 ppm). Bentuk fosfor yang paling diminan dijumpai berupa fraksi Fe-P kemudian diikuti oleh Al-P dan Ca-P. Nilai Fraksi Fe-P tertinggi terdapat pada lapisan bawah permukaan hutan sekunder (2141,59 ppm), Nilai fraksi Al-P tertinggi terdapat pada lapisan permukaan padang rumput (12,32 ppm), Nilai Ca – P hanya dijumpai pada penggunaan lahan hutan sekunder lapisan atas permukaan (413,61 ppm) dan lapisan bawah permukaan (2141,56 ppm) The Study of Phosphorus (P) Fractionation on some Patterns the Use of Ultisol Dry Land in Jalin Jantho, Aceh BesarAbstract. This study aims to determine the composition of the phosphorus fraction (P) in some patterns in the use of Ultisol dry land in Jalin Jantho, Aceh Besar. This research uses descriptive method based on observation of soil characteristics in the field and soil analysis in the laboratory. The analysis of research indicated that the highest P-content was encountered on the topsoil wetland (1.6 ppm), the highest total P-content was found in the use of subsoil secondary forest (76 ppm). The most visible phosphorus form is found in the Fe-P fraction followed by Al-P and Ca-P. The highest Fe-P fraction value is found in the subsoil secondary forest (2141,59 ppm). The highest Al-P fraction is found on the grassland topsoil (12,32 ppm), Ca-P value is only found in the use of topsoil (413.61 ppm) and subsoil secondary forest (2141.56 ppm)

TRANSFORMATION OF THE WATER QUALITY IN THE SŁUPIA RIVER (POLAND)

The objective of this paper was to present the water quality changes of the one of Polish rivers - Słupia River, located in the Pomeranian Region. The Słupia River receives pollutants derived from non-point and point sources of pollution. This is due to the agricultural and forested character of the river’s basin and the location of the towns of Słupsk and Ustka on the river. The elaboration covers the period from 1988 to 2007 and is based on hydrological data, completed as a part of surface water monitoring programme run by the Inspectorate for Environment Protection and the Institute of Meteorology and Water Management. The changes of physicochemical properties of Słupia River i.e. phosphorus and nitrogen concentrations, BOD5, and amounts of heavy metals were studied. Presented data, showed that the Słupia River has responded to a major nutrient loading reduction. The current concentration of nitrogen and phosphorus form in river allows qualifying the water to first quality class.