Due to the ever present problem of excessive eutrophication of both surface waters and their main receiver, i.e. Baltic Sea, it becomes important to determine not only the concentration of nutrients ...in selected river profiles, but also an attempt to answer the question of which of the elements is a factor limiting the growth of biomass. Biological production in surface area is dependent on a number of factors including the relations between the nitrogen and phosphorus during photosynthesis. The study, whose results were presented in the article, was conducted in 2012–2014 on two littoral river basins, Rega and Słupia, in three cycles throughout the year including both vegetation period, the period after the removal of crops from the fields and the period of early spring, immediately after the thaw snow. On the basis of the results were analyzed variability of daily and seasonal concentrations of biogenic compounds and on the basis determined which of the elements limits the increase in biomass in selected catchments using the dependence that exists between the nitrogen and phosphorus in surface waters called Redfield ratio.
Bu çalışmada, elektrot materyali olarak paslanmaz çelik ve demirin kullanıldığı sürekli şartlarda işletilen Elektrokoagülasyon (EK) model reaktörü ile tavuk kesimhanesi atıksularından fosfor ...gideriminde pH (4-10), akım yoğunluğu (10-40 A/m2) ve elektroliz süresi (5-15 dk) gibi işletme parametrelerinin etkisi araştırılmıştır. Elektrot materyalleri; ilk olarak Anot ve katot elektrotun paslanmaz çelik (Anot-PÇ/Katot-PÇ) ve ikinci olarak anot demir, katot ise paslanmaz çelik materyalinden (Anot-Demir/Katot-PÇ) olacak şekilde iki farklı birleşim değerlendirilmiştir. Deneysel çalışma sonuçlarının değerlendirilmesi ve optimum işletme şartlarının belirlenmesi amacı ile Box-Behnken istatistiksel analiz modeli kullanılmıştır. Optimize edilen koşullarda, PÇ/PÇ elektrotunun kullanıldığı EK model reaktöründe giderilen fosfor konsantrasyonu için R2 (Regresyon) değeri 0,99 olarak; Fe/PÇ elektrotunun kullanıldığı EK model reaktöründe giderilen fosfor konsantrasyonu için R2 değeri 0,98 olarak tespit edilmiştir. Fosfor konsantrasyonu gideriminin en yüksek olduğu optimum değerler; PÇ/PÇ elektrot türü için başlangıç pH 4, akım yoğunluğu: 23,3 A/m2, elektroliz süresi: 9,2 dk olarak tespit edilirken, Fe/PÇ elektrot türü için elektrot türü için başlangıç pH 4, akım yoğunluğu: 40 A/m2, elektroliz süresi: 15 dk olarak tespit edilmiştir. En yüksek giderimin sağlandığı şartlarda PÇ/PÇ elektrot türünde, Fe/PÇ elektrot türüne göre daha az akım yoğunluğu ve elektroliz süresine ihtiyaç duyulduğu belirlenmiştir.
Phosphorus flows in Swedish agriculture and food chain were studied by material flow analysis. The system studied included agriculture, food consumption, related waste and wastewater from private ...households and municipal wastewater treatment plants. Swedish farmland had net annual phosphorus inputs of ∼ 12 600 metric tons (4.1 kg P ha -1 ) in 2008—2010. The total import of phosphorus in food and feed to Sweden exceed imports of phosphorus in fertilizers. Despite strict animal density regulations relating to manure phosphorus content, phosphorus is accumulating on Swedish animal farms. The total quantity of manure produced greatly exceeds imported mineral phosphorus fertilizer and almost equals total phosphorus inputs to Swedish farmland.
Efek sisa pupuk kandang diperkaya fosfat alam (FA) bermanfaat untuk musim tanam berikutnya. Tujuan penelitian untuk mengetahui pengaruh pukan diperkaya FA (pukan) dalam bentuk granular dan di ...inokulasi biodekomposer terhadap nutrisi jerami jagung manis (Zea mays saccharata) pada musim tanam kedua. Penelitian lapang menggunakan rancangan acak lengkap dengan 7 perlakuan dan 4 ulangan pada tanah vertisol. Dosis unsur hara P (FA), N (urea), dan K (KCl) masing-masing 66 kg/ha, 200 kg/ha dan 125 kg K/ha. Dosis pukan 30 t/ha dan semua diperkaya FA. Perlakuan yang diberikan adalah T0 (pukan), T1 (pukan+EM4), T2 (pukan+starTmik), T3 (pukan+stardec), T4 (pukan granular+ EM4), T5 (pukan granular+starTmik), T6 (pukan granular+stardec). Panen jagung manis pada umur 70 hari setelah tanam, dan jerami dipotong untuk mendapatkan data kadar protein kasar (PK), fosfor (P) dan kalsium (Ca). Hasil penelitian menunjukkan bahwa efek residu pukan tanpa biodekomposer (T0) menghasilkan kadar PK jerami jagung manis berbeda tidak nyata dibanding perlakuan lainnya, kecuali pada T4. Efek residu pukan dalam bentuk granular maupun non-granular dengan inokulasi biodekomposer menghasilkan kadar P dan Ca jerami jagung manis nyata lebih tinggi dibanding tanpa biodekomposer. Dapat disimpulkan bahwa efek residu pukan dengan inokulasi biodekomposer mempunyai kemampuan setara dalam menghasilkan kadar PK, namun lebih tinggi kadar P dan Ca jerami jagung manis dibanding pukan tanpa biodekomposer.
Source-separated black water (BW) (toilet water) containing 38% of the organic material and 68% of the phosphorus in the total household waste (water) stream including kitchen waste, is a potential ...source for energy and phosphorus recovery. The energy recovered, in the form of electricity and heat, is more than sufficient for anaerobic treatment, nitrogen removal and phosphorus recovery. The phosphorus balance of an upflow anaerobic sludge blanket reactor treating concentrated BW showed a phosphorus conservation of 61% in the anaerobic effluent. Precipitation of phosphate as struvite from this stream resulted in a recovery of 0.22 kgP/p/y, representing 10% of the artificial phosphorus fertiliser production in the world. The remaining part of the phosphorus ended up in the anaerobic sludge, mainly due to precipitation (39%). Low dilution and a high pH favour the accumulation of phosphorus in the anaerobic sludge and this sludge could be used as a phosphorus-enriched organic fertiliser, provided that it is safe regarding heavy metals, pathogens and micro-pollutants.
Two field experiments with drained plots on clay soils (60% and 25% clay) demonstrated a significant reduction in leaching of total phosphorus after application of structure lime. Aggregate stability ...was significantly improved. Phosphorus leaching in particulate form was significantly reduced following structure liming at the site with a very high clay content. Sites representing low (50 mg kg ⁻¹) and high (140 mg kg ⁻¹) levels of phosphorus extractable with acid ammonium lactate in topsoil displayed differing effects on leaching of dissolved reactive P (DRP). This form of phosphorus was only significantly reduced compared with the control at one site with high topsoil phosphorus status and relatively high (17–18%) degree of phosphorus saturation in the subsoil. Laboratory experiments with simulated rain events applied to topsoil lysimeters from the same site also demonstrated a significant reduction in leaching of DRP. These findings indicate that structure liming is an appropriate leaching mitigation measure on soils with both a high clay content and high soil phosphorus status.
Microalgae can be used for the treatment of municipal wastewater. The application of microalgal biofilms in wastewater treatment systems seems attractive, being able to remove nitrogen, phosphorus ...and COD from wastewater at a short hydraulic retention time. This study therefore investigates the area requirement, achieved effluent concentrations and biomass production of a hypothetical large-scale microalgal biofilm system treating municipal wastewater. Three scenarios were defined: using microalgal biofilms: (1) as a post-treatment; (2) as a second stage of wastewater treatment, after a first stage in which COD is removed by activated sludge; and (3) in a symbiotic microalgal/heterotrophic system. The analysis showed that in the Netherlands, the area requirements for these three scenarios range from 0.32 to 2.1 m2 per person equivalent. Moreover, it was found that it was not possible to simultaneously remove all nitrogen and phosphorus from the wastewater, because of the nitrogen:phosphorus ratio in the wastewater. Phosphorus was limiting in the post-treatment scenario, while nitrogen was limiting in the two other scenarios. Furthermore, a substantial amount of microalgal biomass was produced, ranging from 13 to 59 g per person equivalent per day. These findings show that microalgal biofilm systems hold large potential as seasonal wastewater treatment systems and that it is worthwhile to investigate these systems further.
Soil testing has been an accepted agricultural management practice for decades. Interpretations and fertility recommendations based on soil analyses and the information obtained with soil samples on ...cropping systems, tillage practices, soil types, manure use, and other parameters have contributed to the increased efficiency of agricultural production. Recently, however, analyses of long‐term trends in soil test P values have shown that soil P in many areas of the world is now excessive, relative to crop P requirements. The role of P in the eutrophication of surface waters and emerging concerns about the human health impacts of toxic algal/dinoflagellate blooms have heightened public awareness of nonpoint source pollution by agricultural P. The greatest concerns are with animal‐based agriculture, where farm and watershed‐scale P surpluses and over‐application of P to soils are common. The need for nutrient‐management plans based on N and P is now an issue of intense debate in the U.S. and Canada. This paper addresses three issues: Should the applications of organic wastes and fertilizers be based on soil P and, if so, what is the most appropriate testing method to assess environmental risk? How can our knowledge of soil P chemistry be integrated with the expertise of hydrologists, agronomists, aquatic ecologists, and others to assess the risks that P in agricultural soils poses to surface waters? And, finally, how can we use soil P testing to evaluate new best management practices (BMPs) now being developed to reduce P transport from soil to water?
In this study, a consistent basin-wise monthly time series of the atmospheric nutrient load to the Baltic Sea during 1850-2006 was compiled. Due to the lack of a long time series (1850-1960) of ...nutrient deposition to the Baltic Sea, the data set was compiled by combining a time series of deposition data at the Baltic Nest Institute from 1970 to 2006, published historical monitoring data and deposition estimates, as well as recent modeled Representative Concentration Pathways (RCP) emission estimates. The procedure for nitrogen compounds included estimation of the deposition in a few intermediate reference years, linear interpolation between them, and the decomposition of annual deposition into a seasonal deposition pattern. As no reliable monitoring results were found for the atmospheric deposition of phosphorus during the early period of our study, we used published estimates for the temporal and spatial pattern of the phosphorus load.
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