Polymer composites are used in a varying extent and are challenging the use of traditional materials due to the push towards sustainable development. They have replaced steels and aluminum alloys in applications. Polymer composites are used in load-bearing and semi-load bearing applications in automotive, transport and aerospace industry due to their good characteristics. Polymer poses beneficial characteristics such as chemical stability, corrosion resistance, attractive strength-to-weight ratio, and be processed with ease. However, many polymers are highly flammable, making them a fire hazard. The fact that polymer composite is highly flammable, they need to undergo fire safety treatment that are sustainable towards the environment and humans. In this study biochar and ammonium polyphosphate (APP) were added in different combinations to epoxy resin. The purpose was to evaluate the synergistic effects that biochar and APP has on epoxy composite and how it will affect the fire- and mechanical properties. Additionally, developing a composite that retains a high compressive strength while increasing its thermal stability. Lastly, evaluate if the best performing composite could be recommended for load/semi-load‑bearing applications along with being sustainable towards the environment and humans. This thesis was conducted through literature study and laboratory work where three different tests were done such as cone calorimeter (CC), thermogravimetric analysis (TGA) and compressive test. The CC and TGA test were done to analyze the synergistic effect APP and biochar had on epoxy composites fire properties, but also determine which composition obtained the best fire properties. The compressive test was done to analyze the synergistic effect APP and biochar had on the epoxy composites mechanical properties. From the CC- and TGA tests it was observed that biochar and APP individually improved the fire properties of the epoxy where a decrease in peak heat release rate per unit area (PHRRPUA) and a decrease in mass loss was obtained. Additionally, it was noticed that the addition of only APP had a greater impact in improving the fire properties compared to only biochar. However, a combination of 15 wt.% biochar and 20 wt.% APP improved the fire properties the most. The compression tests indicated that biochar reduced the compressive strength drastically compared to the neat epoxy, since the biochar-based samples exhibited a porous structure. The addition of only APP in the epoxy showed a minimal reduction in compressive strength compared to neat epoxy. In conclusion, biochar and APP were improving the fire properties of epoxy composite whereas the compressive strength decreased. Overall, by an addition of only APP to the epoxy, the fire properties were enhanced where the compressive strength was conserved compared to neat epoxy. Since the composition with only APP performed the best overall, this composition can thereby be recommended for development in load/semi-load-bearing applications.

Water polluted by metals and phosphates can be hazardous to both the environment and human health. The aim of this study was used to improve understanding of the adsorption properties of low-cost, green adsorbents for removal of pollutants from aqueous solution. Biochar was used as an adsorbent, which was produced from the gasification of pine wood waste and the fast pyrolysis of Douglas fir. Biochar is a bio-renewable product that can easily be modified, and the cost is lower compared to other adsorbents like activated carbon. The gasifier produced biochar was modified by coating the biochar surface with chitosan. Douglas fir biochar, produced by pyrolysis, was used in Mg/Al-layered double hydroxides (LDHs) and magnetization modifications. The Mg/Al-LDHs were prepared by co-precipitation using solutions of Mg and Al salts and NaOH treatment. The magnetization modification of the biochar was prepared by magnetite (Fe3O4) precipitation onto the biochar’s surface from Fe2+/Fe3+ solution upon NaOH treatment. Chapter I provides an introduction into biochar production, uses, and modification methods. Chapter II is a study of the aqueous adsorption Cu2+ and Cd2+ metals using chitosan coated and uncoated gasifier biochars. Chapter III focused on the removal of phosphate from aqueous solutions. Different ratios of Mg:Al in the LDHs were used to test the ratio’s affect on the adsorption properties of the modified adsorbents. Chapter IV describes the removal of phosphate from water using LDH modified biochars that are magnetized. This study looks at how the order in which the modifications were done influences the biochars adsorption ability. The surface chemistry and composition of each biochar in chapters II-IV were examined by SEM, SEM-EDX, TEM, PZC, XRD, elemental analysis, and surface area measurements. Each biochar’s adsorption ability was studied by pH effects, kinetics, and maximum capacity for the analyte.

The objectives of this dissertation’s studies were to determine the effects of different additives on biomass wood pellets’ physical properties and the production energy required to produce each treatment. Chapter II was completed using a pneumatic pelletizer as a small scale test to determine effects of different additives. The pneumatic pelletizer was a good indicator of which additives can be successfully pelletized. The results of this chapter show that using bio-oil can significantly increase calorific value, without significantly decreasing durability and significantly increasing production energy required. Corn starch, in a 4% treatment, was shown to not hinder durability or calorific value significantly, but significantly lower production energy. Biochar was shown to be an additive insignificant in production due to such a low durability. Chapter III is a scaled up pelleting study, which takes additives from Chapter II as well as multiple new additives to determine each one’s effects on the physical properties and production energy effects. The larger scale, Sprout Walden pelletizer gave much different results than that of the pneumatic pelletizer. The results tend to prove beneficial to durability, calorific value, and bulk density with multiple of the treatments. Vegetable oil was a treatment shown to be less beneficial with each increase in additive and would not be recommended in a production setting at such levels. Chapter IV focused on the economic effect of the pellets produced in Chapter III. Equations were made to determine the possible marginal revenue using each of the treatments. The marginal revenue equations take into account the changes in durability and calorific value. Biochar 4%, and vegetable oil at 1% and 2% show that an increase in marginal revenue could be possible with these treatments.

The objectives of this study were to investigate nutrient retention, intI1 prevalence, and compost maturity rates for poultry litter co-composted with 5, 10, and 20% southern yellow pine biochar and with or without 2% wood vinegar (WV). Samples were collected at 0, 57, and 112 days to measure nitrogen, phosphorus, and potassium (N, P, K) concentrations, microbial counts, pH, moisture content, carbon to nitrogen (C:N) ratio, and intI1 abundance. Composts were aerated once a week and the temperature was also recorded once a week. There was sufficient rainfall so no additional water was added. The results showed that N and P concentrations significantly increased over time in all treatments except 20% biochar and 20% biochar + wood vinegar, while K concentrations significantly decreased. In general, composting with wood vinegar significantly decreased nutrient concentrations; however, all nutrient concentrations were much higher than typical animal manure fertilizers. Increases in biochar level resulted in significantly lower bacteria counts and significantly higher fungi counts. Compost treatments containing wood vinegar had significantly lower bacteria and fungi counts, indicating that southern yellow pine wood vinegar had a biocide effect on microorganisms, and may be not suitable for composting at that application rate. intI1 prevalence was not significantly different among treatments, which may be due to insufficient thermophilic composting. Because thermophilic temperatures were not achieved, the compost was not mature by the end of the study; therefore, compost maturity rates could not be determined.

Östersjön har flertalet regionala miljöproblem, exempelvis övergödning samt höga halter av tungmetaller vilka beror på mänsklig påverkan. På Gotland spolas det årligen upp stora mängder släke, alger och vattenlevande växter på stränderna, som idag inte nyttjas i större utsträckning. Denna rapport syftar att bedöma lämpligheten att använda det gotländska släket för produktion av biokol. Under denna studie har ett studiebesök till Gotland, flertalet intervjuer samt en litteraturstudie genomförts vilka lagt grund för beräkningar av energi- och materialbalanser kopplat till släkesbaserad biokolsproduktion. Släket har ett kadmiuminnehåll på cirka 0,9 mg/kg och består till 80 % av vatten, där vanligt förekommande arter är bland annat bandtång och kräkel. För beräkningar av energi- och materialbalanser nyttjades två olika förbehandlingsalternativ av släket, där alternativ A var en värmebehandling och alternativ B innefattar en kompostering samt avlsutande värmebehandling. Alternativ B är mer energieffektiv sett till energiförbrukning per kilo producerat biokol vilket var 14,5 MJ/kg jämfört med 29,8 MJ/kg. Det finns både för- och nackdelar med användning av släke för biokolsproduktion. Släke är en outnyttjad resurs som kan ingå i biokolsframställning, dock är processen energikrävande på grund av det höga vatteninnehållet i biomassan. Användningen av ett kadmiumrikt biokol är även problematiskt i och med risken för utlakning av denna tungmetall. Utifrån resultatet är det därmed svårt att bedöma lämpligheten av ett släkesbaserat biokol. / The Baltic sea has multiple environmental problems, such as over-fertilization and high concentration of certain heavy metals, caused by human activity. Yearly, beach-cast is washed up on the shores of Gotland and this biomass is today not utilised to a considerable extent. This report aims to assess the suitability of producing biochar from the left over beach-cast. During this study a visit to Gotland, interviews and a literature study has been completed, which has laid the groundwork for calculations of energy and material balances regarding algae-based biochar production. The beach-cast contains approximately 0.9 mg cadmium per kg and consists of 80 % water, in which common species found are eelgrass and furcellaria, among others. For the calculations of energy- and material balances, two different pretreatment alternatives were used before the pyrolysis. Alternative A simply uses preheating and alternative B consist of a composting step before a finishing preheating session. The most energy efficient was alternative B as the power consumption per kilo produced biochar was 14,5 MJ/kg compared to 29,8 MJ/kg. The use of beach-cast for manufacturing biochar has benefits as well as disadvantages. Beach-cast is an unexploited resource that could be used for biochar production, but on the other hand the process is demanding energy-wise due to the high amount of water in the biomass. The utilisation of cadmium rich biochar is also problematic due to the risk of the heavy metal leaching. Based on the results it is therefore complicated to estimate the suitability of a beach-cast based biochar.

Biochar’s high porosity and negative surface charge allows for numerous soil and plant benefits such as increased water retention, high nutrient availability, and plant growth. By analysing biochar’s effect of all of these factors, a system can be put in place in which soils can be remediated with the proper soil amendments. This report discusses and tests the effects of varying rates of biochar on pH levels, cation exchange capacity, and nutrient exchangeability (of calcium, magnesium, sodium, and potassium) in soil. Corn plants were also grown in soils of varying amendment types and analysed for plant growth and germination to determine soil effects on the plant. Testing showed significant differences between treatment types in all areas tested except plant germination. A 2:1 ratio of biochar to compost produced the best overall results for the soil used in testing. This treatment maintained acceptable levels of exchangeable nutrients while raising pH and cation exchange capacity, and also raised the plant growth in the soil by 30%. However, for added soil health, gypsum or calcium fertilizer should be added to the soil to remediate low calcium exchangeability. This testing confirmed that biochar does have a strong positive influence on soil and plant health when used in combination with compost.

Shrinking and swelling in Yazoo Clay is a cause of concern for construction projects in Mississippi. This thesis investigated the effects of adding lime and Douglas Fir biochar on the shrinking and swelling capabilities of Yazoo Clay. Samples of Yazoo Clay were mixed with the additives in defined ratios and subjected to the free swell test and the COLE(rod) test. Biochar addition reduced the COLE(rod) of the samples a large amount, while increasing the swelling potential of the clay samples. The addition of lime slightly reduced both the shrinking and swelling potentials of the samples. The mineralogical variability of Yazoo Clay vertically and horizontally could limit the applicability of these results across the formation and is important to be considered before further application. While constrained to one location, this study showed the influence of biochar and lime on the shrinking and swelling capabilities of Yazoo Clay.

Increasing population across the globe paved the way for rapid growth in industrialization. Pharmaceuticals, automotive, textiles, agriculture, electronics, electrical and many other industries discharge different types of heavy metals, dyes and organic contaminants into ground water. These discharges are released into lakes and rivers without prior treatment causing huge environmental impact to the environment. Among different remediation techniques, adsorption was considered the most promising method because of its low-cost and high efficiency. Biomass is considered as the most practical and renewable source for production of bio products and biofuels. Biomass is also used for carbon sequestration and as an essential element to produce hydrochar and biochar which are considered as the 21st century black gold. Hydrochar and biochar can be used as an excellent low-cost adsorbent for the removal of heavy metals, dyes and organic contaminants from water. This dissertation work focuses on, firstly, development of novel oxone treated hydrochar as an adsorbent for the efficient removal of Pb(II) and Methylene Blue (MB) from aqueous solutions. Secondly, preparing novel ozone oxidized hydrochar treated with polyethyleneimine for removal of Remzol Brilliant Blue (RBB) and Remzol Reactive Black (RRB) dyes from aqueous solutions. Thirdly, producing high-performance CO2 activated biochar as an adsorbent for efficient removal of Aniline from aqueous solution. All prepared hydrochar and biochar adsorbents were characterized by SEM, TGA, FTIR, Elemental analysis, conductometric titration, and N2 adsorption-desorption isothermal analyses (BET and BJH). The adsorption capacities were determined by Atomic absorption spectrometry (AAS) and Ultraviolet–visible spectroscopy (UV-VIS) respectively. The adsorption capacity of each prepared biochar or hydrochar was determined and both kinetic and isothermal studies were performed. The optimal preparation conditions and adsorption parameters were determined for each adsorbent.

Heavy metals, oxyanions (NO3-, PO4-), pharmaceuticals, and dyes in aquatic environments are inevitable economic and health concerns. Ingestion of these contaminants, even in trace amounts, causes long and short-term serious threats to human health. Conventional pollutant mitigation strategies can be costly or ineffective. Due to high efficiency, simplicity, low price, adsorbent reuse, and pollutant (e.g., phosphates) recovery, adsorption has been widely used for wastewater purification. Many efficient, environmentally compatible, and cost-effective sorbents have been successfully applied in environmental remediation. Chapter I is about characterization of graphene-coated pinewood biochar hybrids and evaluation of their copper removal performances. Here, we synthesized three types of pinewood biochar-graphene composites consisting of three different graphene precursors and compared their aqueous Cu2+ removal performances against raw pinewood biochar. To the best of our knowledge, no previous work has characterized the copper decontamination by graphene-biochar hybrids. Chapter II is about thermally- and chemically-treated lignite adsorbents for phosphate remediation. We engineered a cost efficient lignite system with co-precipitated Ca2+/Mg2+ followed by pyrolysis at 600 ⁰C to remediate aqueous phosphates. Micro-sized surface deposited oxide/hydroxide/carbonate particles promoted phosphate uptake of Ca2+/Mg2+-modified-lignite by 31 and 72 times, compared to thermally treated lignite (w/o a chemical treatment) and the raw lignite, respectively. The exhausted adsorbent can act as a slow-release fertilizer, which is comparable with commercial phosphate fertilizers. Chapter III is about synthesis of activated lignite [A-L], Ca2+-modified lignite [Ca-L], and Fe3O4 nanoparticle-loaded activated lignite (Fe3O4-A-L) for phosphate remediation. Even though A-L has a very high surface area (2854 m2/g), it did not achieve much phosphate sorption. Ca-L phosphate uptake was highest due to the high concentrations of surface deposited CaCO3, CaO, and Ca(OH)2. A pH-independent (from pH 5 to 9) phosphate removal was reported by highly basic Ca-L. However, the Ca2+ leaching was highest at pH 5. Precipitation of Ca2+ phosphates/hydrophosphates is the major phosphate removal mechanism of Ca-L. Fe3O4 and Fe2O3 sites of Fe3O4-A-L enhanced phosphate adsorption capacity, 8-fold versus A-L (67.6 mg/g vs 8.0 mg/g at 25 ºC). Fe3O4-A-L remediated phosphates via inner-sphere surface complexation and precipitation.

Eutrophication, caused by phosphate, can be detrimental both for the aquatic environment and human health. This research aims to provide deep knowledge about the adsorption properties of low-cost Fe/Mg layered double hydroxide modified biochar (LDHBC) for removal of phosphate from aqueous solution. Firstly, Fe/Mg layered double hydroxide (LDH) was synthesized by mixing FeCl3 and MgCl2. 6H2O salts in water, followed by NaOH treatment (coprecipitation method). For LDHBC, FeCl3, and MgCl2. 6H2O salts were dissolved in water, and Douglas fir biochar was added to the salts mixture to make a slurry, followed by NaOH treatment. The surface chemistry and elemental composition of both adsorbents and phosphate-laden adsorbents were characterized using Elemental analysis, BET, PZC, TGA, DSC, XRD, SEM, and TEM. Adsorption ability of LDH and LDHBC was studied by pH effects, kinetics, and the highest capacity for the analyte.