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Three oxidants have been evaluated for use as alternative chemical pretreatments for Fena Lake, a surface water that supplies the U.S. Navy's Public Water System (PWS) on the volcanic island of Guam. The study consisted of two investigative components. The first and primary component included a bench-scale evaluation to study the effects of different pre-oxidant chemicals on the formation of chlorinated disinfection by-products (DBPs). The second and ancillary component included a series of water treatment and distribution system management studies that analyzed DBP formation within the treatment plant and water distribution system. The goal of this research was to reduce total trihalomethane (TTHM) and the five haloacetic acid (HAA5) formations in the PWS. In the primary component of the research, raw surface water from Fena Lake was collected by U.S. Navy personnel and shipped to University of Central Florida (UCF) laboratories for experimentation. Bench-scale tests that simulated the coagulation, flocculation, sedimentation and filtration (CSF) that comprises the Navy Water Treatment Plant (NWTP) were used to evaluate the use of two alternative pre-oxidants, potassium permanganate (KMnO4) and chlorine dioxide (ClO2) in lieu of gaseous chlorine (Cl2). The research assessed DBP formation by comparing several pretreatment scenarios, namely: (1) no pretreatment, (2) chlorine pretreatment, and (3) alternative oxidant pretreatment. KMnO4 pretreatment resulted in the lowest percent reduction of TTHMs and HAA5 relative to chlorine pretreatment, at 5.7% and 22.7%, respectively; however, this amount was still a reduction from the results demonstrated for the chlorine pretreatment condition. Without using a pre-oxidant, TTHM and HAA5 formation were reduced by 22.8% and 37.3%, respectively, relative to chlorine pretreatment. Chlorine dioxide demonstrated the greatest TTHM and HAA5 reduction relative to chlorine pretreatment at 34.4% and 53.3%, respectively. The second component of research consisted of a series of studies that evaluated distribution system operations and management alternatives to identify opportunities that could achieve DBP reduction within the PWS. Three concerns that were addressed were the NWTP's compliance with the U.S. Environmental Protection Agency's (USEPA's) Stage 2 Disinfectants/Disinfection By-Products (D/DBP) Rule, variable hydraulic detention times within a small subdivision in the distribution system, and severe weather. It was determined that: (1) A decision based on in-plant studies to cease prechlorination at the NWTP resulted in a decrease in TTHMs and HAA5s throughout the distribution system by 62% and 75%, respectively; (2) A fluoride tracer study led to the discovery of a valved pipeline responsible for elevated DBPs because of excessive water age that when exercised and managed resolved intermittent DBP spikes in the PWS; and (3) when the NWTP's ballasted floc clarifier (BFC) was operated in-series prior to the conventional CSF process during severe weather conditions the TTHM and HAA5 were below 39 ug/L and 29 ug/L, respectively, proving BFC in-series is a practical option for the plant during severe weather.

Oil shale is a valuable natural resource of oil. The United States has only 5% of the known world reserves of recoverable crude oil and about 73% of the known world reserves of recoverable oil shale. Before there can be full-scale commercial development of oil shale, the problems associated with the large amounts of wastes generated by the processing of the shale must be solved. The wastes have a complex chemical matrix. It is felt that the spent shale can be used as a sorbent to either treat or pretreat the contaminated process waters or could be codisposed with the process waters, Quite extensive work has been done in exploring this alternative with respect to inorganic constituents, but that with organic constituents has been mainly restricted to the measurement of total organic carbon. This study was done to base the analysis of the suitability of the spent shale as a sorbent upon individual compounds so that a more fundamental understanding could be obtained as to how families of compounds behave. / Ph. D.

Agricultural production in Sweden account for a large contribution of the territorial GHG emissions. System optimization, fossil fuel removal and increased circularity is therefore of great importance in order to reach the national net zero emission target by 2045. Biochar production from biomass side flows is a cost-efficient method for carbon dioxide removal which could help to reduce the climate impact of agricultural systems. This study aimed to investigate the potential for climate change mitigation by implementing biochar production from wheat straw at farm level in Sweden. A life cycle perspective was used to assess the climate change impact for production of 1 Mg wheat, with three scenarios for straw management 1) biochar production and application on fields 2) straw incorporation into soil and 3) district heat production. A time distributed LCI was used to include the time dynamics of soil processes. Climate impact was assessed using two metrics: Total GWP100 impact(static) and global surface temperature change (time dynamic). Excess thermal energy from the pyrolysis process was assumed to be used for drying of grains and heating buildings at the farm. The results showed a total GWP100 impact of 214 kg CO2-eq/Mg wheat in the scenario with biochar production, which compare to the impact of 425-429 kg CO2-eq/Mg wheat for the scenarios with conventional straw management practices. The temperature response was ca 50 % lower all throughout the analysed time period, compared to the scenarios with straw incorporation or district heat production. The largest contribution to the impact reduction was achieved from carbon sequestration from biochar application to soil amounting to 223 kg CO2-eq/Mg. A sensitivity analysis of the biochar yield (kg biochar produced per kg of dry mass feedstock) for pyrolysis of straw confirmed that biochar production was preferable over other straw management practices for lower biochar yields as well. In conclusion, utilizing straw for biochar production could have a large potential for reducing the climate impact from wheat production in Sweden. However, a combination of measures for climate change mitigation is needed to reach net zero emissions of wheat production. / Jordbruksproduktionen står idag för en betydande del av Sveriges territoriella växthusgasutsläpp. För att minska jordbrukssektorns klimatpåverkan krävs åtgärder såsom material och energiåtervinning, utfasning av fossila bränslen och elektrifiering. För att nå det nationella klimatmålet om nollutsläpp år 2045 krävs även åtgärder för infångning och lagring av koldioxid. Biokolsproduktion av restprodukter och avfall i form av biomassa är en kostnadseffektiv och lättillgänglig metod för kolinlagring. Pyrolys är en termokemisk process som sker när biomassa upphettas till höga temperaturer utan tillgång till syre. Produkterna från processen är syngas, pyrolysolja och biokol. Processen optimeras utifrån vilka produkter som är önskade och syngas förbränns ofta för att tillföra energi och upprätthålla reaktionen. Biokol används därefter främst som jordförbättringsmedel i planteringar men kan även användas för vattenfiltrering, som fyllnadsmaterial i betong, applicering på åkermark och som tillsatts i djurfoder. Efterfrågan och produktionen av biokol är än så länge relativt liten i Sverige. Då det finns en stor tillgång på biomassa från restprodukter inom jordbruket så finns även en stor möjlighet att minska sektorns klimatpåverkan genom pyrolys och biokolsproduktion. Syftet med denna studie är att undersöka hur implementering av biokolsproduktion från vetehalm skulle kunna bidra till minskad klimatpåverkan från veteproduktion. Studien utförs med ett gårdsperspektiv och har målen att: Identifiera och kvantifiera växthusgasutsläpp för relevanta materialflöden och processer inom veteproduktion. Beräkna klimatpåverkan utifrån ett livscykelperspektiv för produktion av 1 Mg vete under tre scenarion för halmhantering 1) biokolsproduktion och applicering på fält 2) halminblanding i jord 3) energiåtervinning genom produktion av fjärrvärme.  Klimatpåverkan, GWP100, beräknades med mätenheten (kg CO2-eq/Mg vete) och beskriver den totala påverkan från de ackumulerade utsläppen över en 100 års tidshorisont som förutsätter att alla utsläpp sker under det första året. För att kunna inkludera ett tidsperspektiv och ta hänsyn till icke-fossila utsläpp av CO2, markprocesser och koncentrationen av växthusgaser i atmosfären över tid, så beräknades även temperaturförändringen av den globala yttemperaturen (K/Mg vete och år), ΔT. Dessa beräkningar utfördes genom att använda tidsdistribuerade utsläpp för en 100 års period och klimatpåverkan, ΔT, beräknades för 150 år. Startåret för beräkningarna och veteproduktionen var satt till år 2019. Gården antogs producera höstvete årligen, utan växelbruk, under en tidsperiod på 20 år. Biokolsproduktion antogs ske på gården och värmeöverskottet antogs användas till torkning av vete och värme till byggnader på gården. En systemexpansion gjordes för att modellera utsläppsminskningen från ett lokalt fjärrvärmeverk där halmen antogs ersätta träpellets producerade av skogsrester.  Resultatet visade en klimatpåverkan av 214 kg CO2-eq/Mg vete. för scenariot med biokolsproduktion, 425 kg CO2-eq/Mg vete för scenariot med fjärrvärmeproduktion och 429 kg CO2-eq/Mg vete för scenariot med hamninblandning i jord. För den tidsdynamiska klimatpåverkan hade scenariot med biokolsproduktion en genomgående ca 50 % lägre temperaturpåverkan under hela tidsperioden. Resultatet visade även att kolinlagringen från biokol var den största bidragande faktorn till den minskade klimatpåverkan. Användning av överskottsvärme från pyrolysprocessen hade även ett betydande påverkan till minskade klimatutsläpp.  Biokolsproduktion av restprodukten vetehalm har därigenom en stor potential till att minska klimatpåverkan från veteproduktion. Effekten av biomassaomvandlingskvoten för pyrolys av halm (mängd producerad biokol per tillförd mängd biomassa) analyserades genom en känslighetsanalys som fann att biokolsproduktion från halm är fördelaktigt även vid lägre omvandlingskvoter, 20 %. En ökning av biomassaomvandlingskvoten med 5 % kan ge ytterligare en minskning på 16-20 % av de totala utsläppen. Även effekten av jordförbättrande egenskaper som skördeökning och minskade markutsläpp av N2O analyserades. Då biokolsmängden per hektar är relativt låg och antas ge effekt endast ett år, så var dessa effekter på den totala klimatpåverkan försumbara. De ackumulerade effekterna av biokol som jordförbättring undersöktes dock inte, men skulle eventuellt kunna ge en mer betydande effekt.  För att bättre kunna analysera klimateffekterna av jordförbättring krävs dock mer forskning om effekter av biokol under svenska odlingsförhållanden över en längre tid. För att dessutom få en mer övergripande bild av potentialen för implementering av biokolsproduktion inom jordbrukssektorn så rekommenderas framtida studier för analys av olika sorters grödor, växtföljder, restprodukter och regioner.  Utifrån resultatet dras slutsatsen att gårdsproduktion av biokol från vetehalm har en möjlighet att minska klimatpåverkan från vete med ca 50 % jämfört med annan halmhantering. Biokolsproduktion är även fördelaktigt när tidsdynamiska effekter av utsläppen inkluderas. För att nå en klimatneutral veteproduktion krävs dock även andra åtgärder.

With over one hundred years of commercial cultivation, sugar cane is one of the most valuable agricultural botanical resources in the World. This position is not only based on production of sugar from sugar cane but also it is, to a great extent, as a result of the increasing importance of sugar cane by-products and side industries. Furthermore, with the advancement of science; awareness of inharmonious growth of materials and energy consumption, and the desire to minimize the negative impacts of industrial pollutants and materials, the scope for using sugar cane is still developing rapidly. Bagasse, molasses and filtered mud are the most important by-products in the process of production of sugar from sugar cane. Among these by-products, bagasse is both a biomass resource for producing energy and is one of the most important agricultural wastes, which can be used in different side industries. Therefore, it was chosen for study in this research as it offers considerable potential as a source of energy. Bagasse is often used as a primary fuel source for sugar mills; when burned in quantity, it produces sufficient heat energy to supply all the needs of a typical sugar mill, with energy to spare. To this end, today a secondary use for this waste product is in combined heat and power plants where its use as a fuel source provides both heat and power. With a suitable energy production technology, bagasse can be used as a fuel in CHP for high efficiency energy generation. Today, with regard to the low efficiency of traditional methods, the high cost of disposal of waste materials and environmental pollution, the use of modern methods such as anaerobic digestion for the production of biogas has increased. The collected biogas from the process of anaerobic digestion provides a renewable energy source similar to natural gas, but with less methane and lower heating value, that is suitable for use in CHP plants. In this research, a comparison with different bagasse energy production technologies leads to the selection of anaerobic digestion as the most suitable for use in Iran. Then a typical biogas CHP is assumed, and the biogas system is designed. Finally, the potential for the development of biogas CHP plants with bagasse in Iran is addressed through a study of the economic and environmental aspects.

Chemical disinfection is the cornerstone of safe drinking water. However, the use of chemical disinfection results in the unintentional formation of disinfection by-products (DBPs), an outcome of reactions between the disinfectant and natural organic matter (NOM) present in the native (raw) water. DBPs are suspected carcinogens, and as such, have been regulated by the U.S. Environmental Protection Agency (USEPA) under the Safe Drinking Water Act (SDWA). This document reports the results of a study that investigated the use of chlorine dioxide pre-oxidation for the reduction of DBP precursors, and subsequently, DBP formation potential (FP). To determine the effectiveness of the chlorine dioxide pre-oxidation process, two surface waters were studied: raw water from Lake Claire (Orlando, FL) and raw water from the East Maui Watershed (Makawao, HI). Lake Claire water contains approximately 11-12 mg/L of NOM and 35 mg/L as CaCO3 of alkalinity, while the Maui source water typically ranges between 7-8 mg/L of NOM with 2-10 mg/L as CaCO3 of alkalinity. Two chlorine dioxide doses were investigated (0.75 mg/L and 1.5 mg/L) and compared to a control to quantify the effectiveness of this advanced pre-treatment oxidation process. Water collected at each site was subject to the following treatment process: oxidation, coagulation, flocculation, sedimentation, ultrafiltration, and disinfection with free chlorine. Disinfection by-product formation potential (DBPFP) analysis showed that ClO2 pre-oxidation, in general, increased the 7-day DBPFP of the East Maui water, and decreased the 7-day DBPFP of the Lake Claire source water. For the Lake Claire water at the higher ClO2 dose, total trihalomethanes (TTHM) were decreased by 37 percent and the five regulated haloacetic acids (HAA5) by 23 percent. For the East Maui source water at the higher ClO2 dose, TTHM’s were increased by 53 percent and HAA5’s by 60 percent. Future research should determine the effect of alkalinity on DBPFP, which could be the reason why chlorine dioxide pre-oxidation caused one water source’s DBPFP to decrease and the other to increase.

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Channel catfish raising is an important aquaculture in the United States. Mississippi ranks No.1 in catfish production for continuous 4 years. However, catfish fillet processing generates huge amount of by-products, including heads, bone frames, visceras and skins, which contain significant amount of proteins. Removing and utilization of proteins from the by-product would add value to the catfish industry. Collagen was extracted from catfish skin by: (1) acid extraction; (2) homogenization-aided; and (3) pepsin-aided extraction methods. Kinetic analysis of the extraction was performed. SDS-PAGE was performed to analysis the composition of proteins in collagens extracted under different conditions. Collages extracted by three methods was characterized by solubility test, zeta potential, circular dichroism and gel strength. Protein recovery rate from minced skin extracted with pH 2.4 HCl containing 23.6 KU/g pepsin was the highest (64.19%). Papain, ficin, bromelain, neutrase, alcalase, protamex, novo-pro D and thermolysin were used for the hydrolysis of the mixture of heads and frames. Proteolytic activities of these proteases were examined using AzocollTM as a standard substrate. Degree of hydrolysis (DH) of hydrolysates and enzyme reaction kinetics were investigated. Results indicated that thermolysin had the highest activity (82.9×107 AzU/g) at 50 °C when using AzocollTM as the substrate. Ficin (80 AzU/g) was the most efficient in hydrolyzing the proteins in the ground catfish by-product (DH reaching 71.88%) in 120 min at 30°C among all the enzymes. Thermolysin could be used for industries to hydrolyze protein by-products in terms of hydrolysis efficiency and economy. The hydrolysis curves fit the Peleg model very well, all with R2 higher than 0.91. Myofibrillar proteins were extracted from the mixture of heads and frames with different pH conditions, and made into protein gels. Transglutaminase (TGase) was incorporated to improve the gel structure. Solubility and secondary structures of extracted myofibrillar proteins were studied. Gelling properties of the protein sol were studied by dynamic rheological measurement. Physicochemical, textural and thermal properties of protein gels treated with TGase were investigated. Protein pattern changes of TGase treated protein gel was studied by SDS-PAGE. Results indicated that alpha-helicity of myofibrillar proteins decreased with extraction pH over 9. Storage modulus (G’) of protein sol decreased as the increase of extraction pH. Rheological measurement of TGase treated protein sol showed that excessive TGase could weaken the gel structure. This study provides systematic information for the catfish fillet processing industry to utilize the by-products.

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