Despite recent instability in the global supply of phosphate-rock derived fertiliser and the potential for this to continue into the future, the recovery of phosphorus (P) from wastewater treatment systems, where P is abundant and accessible, is well below maximum potential. Considerable resource is spent on removing P from wastewater in order to comply with environmental standards and to protect aquatic ecosystems from eutrophication, yet there is little emphasis on capturing the P in a way that is optimised for re-using it as agricultural fertiliser. To address this lack of innovation in the face of climate change and food insecurity, a concept for a material capable of capturing P from wastewater was developed, with an emphasis on the utilisation of otherwise waste materials and the use of carbon neutral or negative production technologies. Based on the demonstrated P capture properties of coal minewater treatment waste (ochre) and biochar made from anaerobically digested feedstocks, a range of biochars were designed and produced using different mixtures of ochre (“OC”), sourced from the UK Coal Authority Minto minewater treatment scheme in Fife, Scotland and anaerobically digested sewage sludge (“AD”), sourced from the Newbridge wastewater treatment plant in Edinburgh. A first generation of materials consisting of either AD or a 1:1 mixture (dry weight basis) of OC and AD were produced in a small-scale batch pyrolysis unit at two pyrolysis highest treatment temperatures (HTTs) (450 and 550°C) to give the biochars AD450, AD550, OCAD450 and OCAD550. These were tested for their P capture properties in repeated P-exposure experiments with pH buffering in comparison to unpyrolysed ochre, activated carbon and a natural zeolite. After 5 days of repeated exposure to a P solution at a wastewater-relevant concentration (20 mg P l-1) replenished every 24 h, relatively high masses of P were recovered by ochre (1.73 ± 8.93×10-3 mg P g-1) and the biochars OCAD550 (1.26 ± 4.66×10-3 mg P g-1), OCAD450 (1.24 ± 2.10×10-3 mg P g-1), AD450 (1.06 ± 3.84×10-3 mg P g-1), and AD550 (0.986 ± 9.31×10-3 mg P g-1). The biochar materials had higher removal rates than both activated carbon (0.884 ± 1.69×10-2 mg P g-1) and zeolite (0.130 ± 1.05×10-2 mg P g-1). To assess the extractability of recovered P and thus potential plant bioavailability, P exposure was followed by repeated extraction of the materials for 4 days with pH 7-buffered deionised water. The AD biochars retained 55% of the P recovered, OCAD biochars 78% and ochre 100%. Assessment of potentially toxic element (PTE) concentrations in the biochars against guideline values indicated low risk associated with their use in the environment. A second generation of materials were produced to examine the scalability of the concept. Mixtures of AD and OC were pelletised with a lignin binder (89.1:9.9:1.0 ratio, dry weight basis) and AD was pelletised with binder (99:1 ratio, dry weight basis). The pelletised feedstocks were pyrolysed in a bench-scale continuous flow pyrolysis kiln at the same two HTTs to give the pelletised biochars PAD450, PAD550, POCAD450 and POCAD550. Analysis of digested biochar samples compared to the previous generation of biochars showed general similarities between the two groups, apart from the substantially lower Fe content. Sub-samples of the pelletised biochars were exposed to a 20 mg l-1 P solution over 6 days, with the solution replaced every 24 h to give the P-exposed biochars EPAD450, EPAD550, EPOCAD450 and EPOCAD550. To probe the mechanisms of P capture by these materials and how feedstock preparation and pyrolysis conditions affected these, spectroscopic analysis using laser-ablation (LA) ICP-MS, X-ray diffraction, X-ray photo-electron spectroscopy (XPS) and scanning electron microscopy coupled with energy dispersive X-ray was performed. The results highlighted the general importance of Fe minerals in P capture and subsidiary roles for Al, Ca and Si. A 3-week barley (Hordeum vulgare) seedling growth experiment was conducted using the pelletised and P-exposed biochars, in comparison with other biochars produced using feedstock which contained high amounts of PTEs. The biochars were also extracted using a range of different methods used to assess the bioavailability of PTEs and nutrients in soils, and the results compared to digests of barley leaves to identify whether any of these could reliably predict plant bioavailability in biochar. The above ground biomass and its total P concentration of barley grown in a 5% mixture of EPOCAD550 in sand was significantly higher than the control (p < 0.05 and p < 0.01, respectively). A significant positive correlation between mean leaf P mass and dry weight leaf yield (R2 = 0.865, p < 0.001) was found, indicating that dry weight yield could be used as an indicator for the P fertilising capability of biochar for barley seedlings. Element concentrations in unbuffered and buffered and (pH 7) 0.01 M CaCl2 biochar extractions were significantly positively correlated with plant leaf concentration for 6 of the 18 elements investigated, more than any of the other extractions. A longer barley growth experiment was conducted, using rhizoboxes, to test the bioavailability of P in the biochars compared to conventional fertiliser. The pelletised and Pexposed biochars were applied to a sandy loam soil with P constraints. Biochar application rates were based on 2% formic acid extractable P, calculated for summer barley using Index 0 soil. Analysis of total leaf length at harvest (12 weeks), dry weight yield, leaf P concentration and leaf P mass showed no significant differences between the biochar treatments, NPK fertilised and NK fertilised controls. This shows that biochar, when applied at low total application rates based on extractable P, is as effective as conventional fertiliser. Now that AD biochar materials have been shown to have useful phosphorus recycling properties in laboratory experiments, additional work is required to optimise their use in wastewater and agricultural systems. The next stage of research should determine their performance in flow-through filtration systems with simulated and real wastewater effluent, as well as their performance in field trials with different crops of interest to demonstrate their potential as viable alternative fertilisers.

Phosphorus (P) is a plant macronutrient and soils located in tropical regions generally show low content of this element. Moreover, these soils are acidic and show high fixing capacity of phosphorus, substantially decreasing fertilizers efficiency. For this reason, annual P inputs to soils are required to obtain feasible crop yields. The main concern regarding P in agriculture is this element is extracted from mines that are being depleted. For this reason, it is necessary to develop recycling P technologies in order economize mineral resources and obtain benefits from low cost sources locally available. Bones are a P-rich material that could be employed for P recycling; however, this sub-product from meat industry needs to be treated prior use to ensure health safety. Pyrolysis is a technology that has gained attention because it does not affect bone mineral structure as does calcination, which is a standard treatment. Performing pyrolysis of bones generates a material called bone char and tests suggests that its efficiency is comparable to common soluble fertilizers obtained from P rocks. Another way to obtain higher crop P and other nutrients absorption as well as yield, is to stimulate symbiosis of plants with arbuscular mycorrhizal fungi (AMF), which are naturally found in soils. However, acidic soils from tropical regions generally difficult plant-AMF interaction due to high amount of exchangeable aluminum present. An alternative to overcome this issue would be to apply pyrolysis to organic wastes, generating a material termed biochar, which is rich in carbon, and sometimes nutrients, assisting AMF-plant symbiosis. Our aim was to produce through pyrolysis a set of bone chars in different temperatures (400, 550 and 800 °C) and atmospheric composition (sealed chamber, N2 flux and steam flux), and perform a detailed characterization of the resultant materials (chapter 1) to verify which possible factors are controlling bone char efficiency as fertilizer in a pot experiment labelled with 32P (chapter 2). To test the symbiotic pathway in P acquisition by plants through biochar use, two biochars from eucalyptus wood chips were produced at 300 and 700 °C and applied to a soil inoculated or non-inoculated with AMF. In this experiment we analyzed plant growth and colonization by AMF as well as nutrient absorption (chapter 3). Additionally, a trial with AMF spore germination evaluation was performed to investigate the possible inhibitory or positive effects of the biochars on AMF fungi. / O fósforo (P) é um macronutriente para as plantas e solos localizados em regiões tropicais geralmente apresentam baixo conteúdo deste elemento. Ainda, estes solos são ácidos e apresentam alta capacidade de fixação de P, diminuindo substancialmente a eficiência de fertilizantes. Por esta razão, adições anuais de P ao solo são requeridas para obtenção de produtividades de plantas economicamente viáveis. A principal preocupação em relação ao uso de P na agricultura é que este elemento é extraído de minas que estão sendo exauridas. Por esta razão, é necessário o desenvolvimento de tecnologias de reciclagem de P a fim de economizar recursos minerais e obter benefícios oriundos de fontes de baixo custo disponíveis localmente. Um material que é rico em P e que poderia ser empregado na reciclagem de fósforo é o osso animal, no entanto, este subproduto da indústria de carnes necessita ser tratado previamente ao uso para garantir segurança sanitária. A pirólise é umas tecnologias que tem recebido atenção porque seu emprego no tratamento de ossos não afeta a estrutura do material como a calcinação, que é um tratamento padrão. Realizar a pirólise de ossos gera um material denominado de carvão de osso (bone char, em inglês), o qual testes sugerem que a sua eficiência é comparável à fertilizantes solúveis convencionais obtidos a partir de rochas fosfáticas. Outra forma de obter maior absorção de P e nutrientes e maior produtividade de cultivos é através do estímulo da simbiose de plantas com micorrízicos arbusculares (FMA), estes naturalmente encontrados em solos. No entanto, solos ácidos de regiões tropicais geralmente dificultam a interação de plantas-FMA devido ao elevado teor de alumínio trocável presente. Uma alternativa para superar esse problema seria a aplicação de pirólise a resíduos orgânicos, gerando assim um material chamado biocarvão, o qual é rico em carbono, e as vezes nutrientes, e poderia auxiliar na simbiose de plantas com AMF. Nosso objetivo foi produzir através da pirólise um conjunto de biocarvões em diferentes temperaturas (400, 550 e 800 °C) e composições atmosférias (câmara selada, fluxo de N2 e fluxo de vapor d\'água) e realizar a caracterização dos materiais resultantes (capítulo 1) para verificar que possíveis fatores controlam a eficiência do carvão de osso em um experimento em vasos com marcação com 32P (capítulo 2). A fim de testar o viés simbiótico na aquisição de P pelas plantas com o uso de biocarvão, dois biocarvões de cavaco de eucalipto produzidos a 300 e 700 °C foram aplicados a um solo inoculado ou não com FMA (capítulo 3). Nesse experimento foram analizados o crescimento de plantas e colonização por FMA, como também a absorção de nutrientes. Adicionalmente, um teste com a germinação de esporos de FMA foi realizado para investiar possíveis effeitos positions ou inibitórios dos biochar em esporos de FMA.

Phosphorus (P) is a plant macronutrient and soils located in tropical regions generally show low content of this element. Moreover, these soils are acidic and show high fixing capacity of phosphorus, substantially decreasing fertilizers efficiency. For this reason, annual P inputs to soils are required to obtain feasible crop yields. The main concern regarding P in agriculture is this element is extracted from mines that are being depleted. For this reason, it is necessary to develop recycling P technologies in order economize mineral resources and obtain benefits from low cost sources locally available. Bones are a P-rich material that could be employed for P recycling; however, this sub-product from meat industry needs to be treated prior use to ensure health safety. Pyrolysis is a technology that has gained attention because it does not affect bone mineral structure as does calcination, which is a standard treatment. Performing pyrolysis of bones generates a material called bone char and tests suggests that its efficiency is comparable to common soluble fertilizers obtained from P rocks. Another way to obtain higher crop P and other nutrients absorption as well as yield, is to stimulate symbiosis of plants with arbuscular mycorrhizal fungi (AMF), which are naturally found in soils. However, acidic soils from tropical regions generally difficult plant-AMF interaction due to high amount of exchangeable aluminum present. An alternative to overcome this issue would be to apply pyrolysis to organic wastes, generating a material termed biochar, which is rich in carbon, and sometimes nutrients, assisting AMF-plant symbiosis. Our aim was to produce through pyrolysis a set of bone chars in different temperatures (400, 550 and 800 °C) and atmospheric composition (sealed chamber, N2 flux and steam flux), and perform a detailed characterization of the resultant materials (chapter 1) to verify which possible factors are controlling bone char efficiency as fertilizer in a pot experiment labelled with 32P (chapter 2). To test the symbiotic pathway in P acquisition by plants through biochar use, two biochars from eucalyptus wood chips were produced at 300 and 700 °C and applied to a soil inoculated or non-inoculated with AMF. In this experiment we analyzed plant growth and colonization by AMF as well as nutrient absorption (chapter 3). Additionally, a trial with AMF spore germination evaluation was performed to investigate the possible inhibitory or positive effects of the biochars on AMF fungi. / O fósforo (P) é um macronutriente para as plantas e solos localizados em regiões tropicais geralmente apresentam baixo conteúdo deste elemento. Ainda, estes solos são ácidos e apresentam alta capacidade de fixação de P, diminuindo substancialmente a eficiência de fertilizantes. Por esta razão, adições anuais de P ao solo são requeridas para obtenção de produtividades de plantas economicamente viáveis. A principal preocupação em relação ao uso de P na agricultura é que este elemento é extraído de minas que estão sendo exauridas. Por esta razão, é necessário o desenvolvimento de tecnologias de reciclagem de P a fim de economizar recursos minerais e obter benefícios oriundos de fontes de baixo custo disponíveis localmente. Um material que é rico em P e que poderia ser empregado na reciclagem de fósforo é o osso animal, no entanto, este subproduto da indústria de carnes necessita ser tratado previamente ao uso para garantir segurança sanitária. A pirólise é umas tecnologias que tem recebido atenção porque seu emprego no tratamento de ossos não afeta a estrutura do material como a calcinação, que é um tratamento padrão. Realizar a pirólise de ossos gera um material denominado de carvão de osso (bone char, em inglês), o qual testes sugerem que a sua eficiência é comparável à fertilizantes solúveis convencionais obtidos a partir de rochas fosfáticas. Outra forma de obter maior absorção de P e nutrientes e maior produtividade de cultivos é através do estímulo da simbiose de plantas com micorrízicos arbusculares (FMA), estes naturalmente encontrados em solos. No entanto, solos ácidos de regiões tropicais geralmente dificultam a interação de plantas-FMA devido ao elevado teor de alumínio trocável presente. Uma alternativa para superar esse problema seria a aplicação de pirólise a resíduos orgânicos, gerando assim um material chamado biocarvão, o qual é rico em carbono, e as vezes nutrientes, e poderia auxiliar na simbiose de plantas com AMF. Nosso objetivo foi produzir através da pirólise um conjunto de biocarvões em diferentes temperaturas (400, 550 e 800 °C) e composições atmosférias (câmara selada, fluxo de N2 e fluxo de vapor d\'água) e realizar a caracterização dos materiais resultantes (capítulo 1) para verificar que possíveis fatores controlam a eficiência do carvão de osso em um experimento em vasos com marcação com 32P (capítulo 2). A fim de testar o viés simbiótico na aquisição de P pelas plantas com o uso de biocarvão, dois biocarvões de cavaco de eucalipto produzidos a 300 e 700 °C foram aplicados a um solo inoculado ou não com FMA (capítulo 3). Nesse experimento foram analizados o crescimento de plantas e colonização por FMA, como também a absorção de nutrientes. Adicionalmente, um teste com a germinação de esporos de FMA foi realizado para investiar possíveis effeitos positions ou inibitórios dos biochar em esporos de FMA.

In this study the opportunities to recycle the phosphorus contained in food handling were identified in four municipalities in the county of Östergötland. The aim was to map the flow and find out whether there were differences between municipalities with food processing industries generating large amounts of waste or phosphorus rich wastewater, or if there were differences between municipalities of different size. It was also investigated to what extent the agricultural demand of phosphorus could be covered by recycling of phosphorus from the food handling system. The result showed that between 27% and 73% of the phosphorus was found in the sludge from wastewater treatment, and that between 13% and 49% of the phosphorus was found in the centrally collected organic waste. This corresponded to 11% of the phosphorus demand on arable land in municipalities with food processing industries generating large amounts of waste or phosphorus rich wastewater, and 8% of the phosphorus demand on arable land in municipalities without such industries.

The Swedish Environmental Agency (SEPA) proposed a national target to increase the rate of phosphorus recycling from wastewater sludge in 2013. Reusing phosphorus from wastewater sludge by spreading it on arable lands raises the risk of contamination and substance deposition in soils. In addition to quantifying the targeted rate of recycling, the proposal has also introduced new thresholds that limit the concentrations of undesired substances in wastewater sludge. This thesis assesses the potential challenges and opportunities in implementing the proposed measure in the Swedish municipality settings. Both qualitative and quantitative data have been gathered from three selected mid-sized Swedish municipalities in the Östergötland County and other data sources. The analytical framework of the thesis is based on the Systems Framework for Phosphorus Recovery and Reuse. Several discrepancies between the national goal to increase phosphorus recycling and local circumstances that affect local decision-making have been identified in this thesis. Reducing the flow of undesired substances into the wastewater stream raises goal conflict and is an enormous challenge which requires regulating the way chemicals are consumed in society. From the policy perspective, the national environmental objectives framework is ambiguous with regards to how local decisions should be directed in line with the national goals. The proposed measure should hierarchically be unequivocal and its implementation needs to be coordinated across all geographical scales. The thesis also highlights that there are significant local opportunities for addressing other sustainability goals through phosphorus recycling measures. Sweden’s commitment to creating a resource-efficient phosphorus cycle affirms that the key for a sustainable phosphorus management is the transformation of path-dependent social and technical systems.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-05-26T13:55:59Z No. of bitstreams: 2 Dissertação - João Vitor de Souza Silva - 2015.pdf: 2745412 bytes, checksum: 72f3f83629987eb1f47a452f8c6e249a (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-05-26T14:06:30Z (GMT) No. of bitstreams: 2 Dissertação - João Vitor de Souza Silva - 2015.pdf: 2745412 bytes, checksum: 72f3f83629987eb1f47a452f8c6e249a (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-05-26T14:06:30Z (GMT). No. of bitstreams: 2 Dissertação - João Vitor de Souza Silva - 2015.pdf: 2745412 bytes, checksum: 72f3f83629987eb1f47a452f8c6e249a (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-03-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The application of phosphate fertilizer is indispensable for achieving sustainable bean production, with P the necessary nutrient virtually throughout your cycle. Thus, cultural management alternatives are being used in the best use of this nutrient, among them the use of brachiaria as plant coverage. The objective of this research was to evaluate the dynamics of phosphorus in the soil with and without the presence of Brachiaria brizantha cv. Marandú as cover crop and common bean response to fertilization. We used the design in a randomized block design with a split plot arrangement, and the plots had P2O5 doses (0, 50, 100, 200 and 400 kg ha-1), and subplots were composed by the presence and absence of brachiaria as previous cover crop cultivation of beans. For distribution of fertilizer was used trencher containing 4 by tractor pull rods, where the grooves were made about 7 cm. The bean sowing occurred after phosphorus fertilization, using a pneumatic drill with 7 individual lines spaced 0.50 m, putting up 10 seeds per meter. Soil samples were collected in three seasons, namely: 1) fifteen days after sowing bean; 2) thirty daysof soil and compost manually placed. after the sowing of bean and 3) post-harvest bean. In the samples, we performed the phosphorus fractions in soil by Hedley technique. In bean plants were evaluated plant height, number of pods per plant, phosphorus content in the leaf, dry mass of plants, weight of 100 grains and productivity. Treatments of P2O5 and presence Brachiaria brizantha cv. Marandú as cover crop, provide changes in the levels of P-labile soil at 15 and 30DAS bean, and P-plábil soil at 15 DAS bean. The presence of Brachiaria brizantha cv. Marandú as cover crop increased the phosphorus content of the bean leaf, resulting in increased productivity. / A aplicação de fertilizante fosfatado é indispensável para obtenção de produções sustentáveis de feijão, sendo o P o nutriente necessário praticamente em todo seu ciclo. Desta forma, alternativas de manejo cultural estão sendo utilizadas visando o melhor aproveitamento deste nutriente, dentre elas o uso da braquiária como planta de cobertura. Objetivou-se com esta pesquisa avaliar a dinâmica do fósforo no solo com e sem a presença de Brachiaria brizantha cv. Marandú como planta de cobertura, bem como a resposta do feijoeiro à adubação fosfatada nestes dois sistemas. O experimento foi conduzido em Latossolo vermelho distroférrico na Universidade Federal de Goiás, Regional Jataí – GO, onde o delineamento utilizado foi o de em blocos ao acaso (DBC), em arranjo de parcelas subdivididas, sendo que as parcelas foram compostas por doses de P2O5 (0; 50; 100; 200 e 400 kg ha-1), e as subparcelas foram compostas pela presença e ausência de braquiária como planta de cobertura anterior ao cultivo do feijoeiro. Para distribuição do adubo foi utilizado sulcador contendo 4 hastes de tração tratorizada, onde os sulcos foram feitos aproximadamente 7 cm do solo e o adubo colocado manualmente. A semeadura do feijoeiro ocorreu após adubação fosfatada, utilizando-se uma semeadora pneumática com 7 linhas individuais espaçadas de 0,50 m, colocando-se 10 sementes por metro. Foram realizadas coletas de amostras de solo em 3 épocas, sendo elas: 1) 15 dias após a semeadura do feijoeiro (15DAS); 2) 30 dias após a semeadura do feijoeiro (30DAS) e 3) pós-colheita do feijoeiro (PC). Nas amostras coletadas, efetuou-se o fracionamento de fósforo no solo pela técnica de Hedley. Nas plantas de feijoeiro foram avaliados altura de plantas, número de vagens por planta, teor de fósforo na folha, massa seca de plantas, massa de 100 grãos e produtividade. Os tratamentos, doses de P2O5 e presença de Brachiaria brizantha cv. Marandú como planta de cobertura, proporcionam alterações nos teores de P-lábil do solo aos 15 e 30DAS do feijoeiro, e P-plábil do solo aos 15 DAS do feijoeiro. A presença da Brachiaria brizantha cv. Marandú como planta de cobertura aumentou o teor de P na folha do feijoeiro, refletindo em aumento de produtividade.

Eutrophication of the Baltic Sea has been an issue for decades and the pollution constantly continues with oxygen deficient bottoms and a damaged marine life as a result. One of the main causes of eutrophication are elevated levels of the nutrient phosphorus. Phosphorus leaks to the sea from various human activities such as agriculture, animal farming and sewage. In Sweden, the onsite wastewater treatment systems are a big problem since they load the Baltic Sea with nearly as much phosphorus as all Swedish municipal wastewater treatment plants. The need for a reduced impact on the Baltic Sea is major and the individual wastewater treatment systems must therefore be looked over. While phosphorus is a contributing factor to eutrophication, it is one of the most important nutrients for all life. Phosphorus builds up our DNA, helps transport of various substances in and out of our cells and provides energy to the cell's processes. We would simply not be able to survive without phosphorus. We ingest phosphorus through the food we eat, which in turn is dependent on fertilizers containing phosphorus. Phosphorus is mined from phosphate ore and the majority of it is used to produce fertilizers. Unfortunately, phosphate ore is not a finite resource and in the last few years it has been realized that the economically extractable phosphorus is a dwindling resource. To be able to produce food for the world's growing population, we need to find ways to recycle phosphorus. In individual drainage systems there is a large potential to catch up phosphorus and then reuse it on agricultural land. This thesis deals with the problems of onsite wastewater treatment systems and suggests measures to improve their status. Ways to recycle phosphorus in combination with having a well-functioning drainage is being investigated and difficulties about the regulations are being discussed. To recover phosphorus and at the same time reduce the burden on the environment should be seen as an incredibly important action, since our sea’s health is acute but lack of the nutrient could have devastating consequences.

This thesis studied the viability of recycling filter substrates as soil amendments after being used in on-site systems for phosphorus (P) removal from wastewater. Focus was put on the materials Filtra P and Polonite, which are commercial products used in compact filters in Sweden. A prerequisite for this choice was to review filter materials and P sorption capacity. The filter substrates (Filtra P, Polonite and wollastonite tailings) were recycled from laboratory infiltration columns as soil amendments to a neutral agricultural soil and to an acid meadow soil to study their impacts on soil properties and yield of barley and ryegrass. The amendments tended to improve the yield and showed a liming effect, significantly increasing soil pH and the availability of P. In another experiment, samples of Filtra P and Polonite were equilibrated in batch experiments with the two soils in order to study the P dynamics in the soil-substrate system.  Batch equilibrations confirmed the liming potential of Filtra P and Polonite and showed that improved P availability in soils was strongly dependent on substrate P concentration, phase of sorbed P, and soil type. Finally, samples of Polonite used for household wastewater treatment were recycled as soil amendments to a mountain meadow and to an agricultural field for wheat cropping. The liming effect of Polonite was confirmed under field conditions and the results were similar to those of lime for the mountain meadow soil. However, the results were quite different for the agricultural field, where Polonite did not affect soil pH or any other chemical and physical soil properties investigated and had no impact on wheat yield and quality. The results from field experiments suggested that Polonite can be safely recycled to meadows and cropping fields at rates of 5-10 ton ha-1 but long-term studies are needed to forecast the effects of accumulation. / QC 20100708

Biochar application as a soil additive is gaining global acceptance. In this era of climate change, biochar use for improved soil productivity is not just a sustainable eco-friendly substitute to synthetic fertilizer, but a noble contributor to the fight against climate change. Although biochar has been accredited with some environmental and agricultural benefits, most studies concentrated on agricultural and biowaste products as feedstocks. This research was designed to explore P-enriched modified-Douglas fir biochar potential as a soil additive. Using corn as a test crop, greenhouse studies were performed on acidic sandy soil, comparing phosphorus enriched modified-Douglas fir biochar efficacy to a commercial synthetic triple superphosphate fertilizer and a control treatment. Incubation studies were also performed to evaluate the liming and heavy metal immobilization efficacies. Firstly, P-enriched modified-Douglas fir biochar’s ability to release plant soluble P was investigated. At various P enrichment concentration, soil plant availability P from P enriched modified-Douglas fir biochar treatments differed insignificantly from superphosphate fertilizer treatment. The direct correlations between both K and Mg recoveries with available soil P, suggested P enriched modified-Douglas fir biochar potential to supply multiple plant nutrients. Secondly, the influence of P uptake on plant growth and P use efficiency was examined. The greater agronomic P use efficiency obtained in P enriched modified-Douglas fir biochar (~32 kg kg-1) than the triple supper phosphate fertilizer (~17 kg kg-1) treatment confirmed P enriched modified-Douglas fir biochar potential as a multiple nutrient released soil additive. Thirdly, biochar-supported phosphate (BP) effectively reduced Pb2+ mobility in simulated contaminated soil. Pb2+reacted with phosphate from Ca10(PO4)6(OH)2 embedded in the biochar supported phosphate at pHPb10(PO4)6(OH)2. Finally, the amendment of acidic soils with modified P-enriched modified-biochar improved soil buffering capacity because of its enhanced ash contents, alkalinity, and surface functional groups. Spectroscopic methods were used to analyze biochar, soil, and plant materials extracts. Several other analytical methods including BET and thermogravimetric analyses were used to characterized biochar. These findings suggest that the use of phosphorus enriched modified-Douglas fir biochar in agricultural soil is a feasible relatively low-cost, effective, and environmentally sustainable soil management and P recycling strategy

Phosphor (P) ist ein für alles Leben notwendiges essentielles Nährelement. Die heutige globalisierte und intensivierte agrarische Produktion benötigt daher die Anwendung großer Mengen Phosphatgesteins, welches eine endliche Ressource darstellt. Gleichzeitig ist der intensive P Gebrauch mit der Eutrophierung von Gewässern verbunden. Es besteht daher Forschungsbedarf um die landwirtschaftliche Produktion zu erhalten. Ziel dieser Arbeit ist die in der Region Berlin-Brandenburg nach Ansatzpunkten für ein verbessertes P Management zu suchen. Hierfür wurde für 2011 eine Substanzflussanalyse (SFA) für P erstellt und Pflanzenproduktion der Jahre 2005-2012 genauer untersucht. Mit Hilfe einer Briefumfrage wurde Daten von 119 Bauernhöfen ausgewertet und mit dem pflanzenverfügbaren P Gehalt (PVP) der landwirtschaftlichen Nutzfläche abgeglichen (LNF). Im Ergebnis zeigt sich für die Region eine negative P Bilanz der LNF(-3.617 t P) und ein hohes Recyclingpotential in Abfall (933 t P) und Abwasser (3.921 t P). P in mineralischen Düngemitteln belief sich auf 4.447 t. Der Gesamtentzug über die Ernte ohne Stroh betrug 15.283 t P und war vergleichbar zu 2006, das Jahr des geringsten P-Entzugs. P-Entzug durch die Ernte schwankte um 7.069 t P/a von 2005 bis 2013, abhängig vom Ertrag der Hauptfeldfrüchte, welche durch die Wetter- und Bodenbedingungen bestimmt wurde. Hieraus ergeben sich mögliche Konsequenzen für P-Flüsse in Bezug auf den Klimawandel, die an den Wasserhaushalt und die Temperatur gekoppelt sind. Die Analyse der Umfrage ergab, dass die kleinen und mittgroßen Einzelunternehmen höhere PVP Werte in der LNF aufwiesen. Die größeren Unternehmensformen regierten empfindlich auf Faktoren, die niedrige PVP-Werte begünstigten. Pacht, Grünland, extensive Rinderhaltung, und viehlose ökologische Landwirtschaft waren mit niedrigen PVP-Werten assoziiert. Biogasanlagen und intensive Tierhaltung, zum Teil auch in Kombination miteinander standen im Zusammenhang mit hohen PVP-Werten. / Phosphorus (P) is an essential nutrient for all life on earth and it is thus needed in agricultural production. Today’s globalized and intensified agricultural production has led to the dependency on P inputs which are fed by phosphate rock, being a finite resource. In contrast, excessive P is a major driver in eutrophication. To sustain agricultural production, there is a need to address this problem. The aim of this thesis was to identify points at which P management could be improved for the region Berlin-Brandenburg. To analyze the system and screen for improvement, a substance flow analysis (SFA) for P for the year 2011 was compiled and for crop production the years 2005-2012 were analyzed. Also, data from 119 farms was obtained by a letter survey and relations between farm structural factors and soil test P (STP) were drawn. The results showed a negative balance for agricultural soils (-3,617 t P) and a considerable recycling potential in waste (933 t P) and wastewater (3,921 t P). Mineral fertilizer inputs amounted to 4,447 t P. P removal by crops was 15,283 t without straw and residues, being almost as low as in 2006; the year with the lowest removal by main crops. P removal by harvest varied significantly (7,069 t P/yr from 2005 to 2013) and depended on the performance of main crops which in turn is influenced by weather and soil. As a result of this, climate change may interact significantly with P flows in agriculture. Here, important variables are connected to conditions in P uptake and plant growth in general (e.g. water supply and temperature). The analyses of farms in the region showed that individual farms of small to medium size had more land with (very) high STP. Larger partnerships and companies/cooperatives were susceptible to factors causing low STP. Tenancy, grassland, extensive cattle and stockless organic farming had a lowering effect on STP. Biogas plants and intensive (cattle) farming, partly combined, were connected to a rise in STP.