In the metalworking industry lubricants are used for   production. For production of seamless stainless steel pipes Sandvik   Materials Technology uses chlorinated pilgering oil, a lubricant produced   from paraffin and chlorine. Today these lubricants are disposed by   incineration when the lubricant is too contaminated so production drops, and   the lubricant is replaced by new lubricant. RecondOil found a solution to clean   these oils instead of disposing them. To assess the environmental impact for   the process of cleaning a screening Life Cycle Assessment (LCA) was   conducted. The functional unit used is the amount of chlorinated pilgering   oil used per year, and impact categories were chosen to be Global Warming   Potential (GWP) and Acidification Potential (AP). The study was conducted for   the impact from cradle to grave. The outcome of the LCA showed that the main   impact for GWP comes from the disposal phase for the conventional process,   which is incineration. For the cleaning and reusing process major impacts   where found to be from the transportation of raw materials, half-fabricates,   products and waste. It was found that only transportation had a major impact   on AP. The results show that for both GWP and AP the recycling process has   lower potential emissions than the conventional method, but further research   on for example electricity and chlorine production is needed to compose a   better comparison of the two processes from a life cycle perspective. / <p>2018-06-08</p>

Mixtures of chlorinated organic pollutants can be found in the soils at chlorophenol-contaminated sawmill, including (inter alia) polychlorinated phenols (CPs), phenoxyphenols (PCPPs), diphenyl ethers (PCDEs), dibenzofurans (PCDFs) and dioxins (PCDDs). These hydrophobic compounds have low water solubility and hence low mobility as truly dissolved compounds. However, they may migrate through the soil at significant rates via co-transport with dissolved organic matter (DOM) and colloids of fine, waterborne particulate matter. In the work underlying this thesis the distribution of chlorinated hydrophobic pollutants between these two mobile fractions in soil samples from five sawmill sites was studied Soils at five sites at which CPs were formerly used were characterized, and found to have complex profiles of chlorinated hydrophobic pollutants. CPs, PCPPs, PCDEs and PCDD/Fs were present at up to ppm-levels. Furthermore, the relative proportions of the pollutants differed from their relative proportions in the preservatives used at the sites, indicating that they have been transported from, and/or degraded in, the soil at different rates. These organic pollutants have low water solubility and strong affinity for soil organic matter (SOM). The importance of SOM for the fate of CPs, PCPPs, PCDEs, PCDFs and PCDDs in soil was investigated by examining the distribution of compounds between the mobile DOM and the immobile particulate organic matter (POM). The partitioning of CPs between DOM and POM was found to be approximately equal. However, the relative strength of association with POM of groups of chlorinated organic pollutants was positively correlated with their hydrophobicity, and thus increased in the order CP &lt; PCPP &lt; PCDE &lt; PCDF &lt; PCDD. Despite the weak association of PCDD/Fs with DOM our investigations found that considerable concentrations of these pollutants were bound to mobile fractions (DOM and colloids, &gt;0.2 µm) in both a groundwater analysis and a leaching test. CPs and PCPP were present at up to ppm- and ppb-levels, respectively, and PCDEs and PCDD/Fs at up to ppt-levels. The importance of transport in association with the mobile fraction (DOM and colloids) increased with increasing hydrophobicity e.g. PCDDs were almost entirely associated with fine particulate matter, while CPs were largely found in the water phase and only minor proportions were associated with colloids.

Sites where 2-chlorobutadiene-1,3 (chloroprene) and 2,3-dichlorobutadiene-1,3 (DCBD) are synthesized for use in chlorobutyl rubber have the potential to release a mixture of at least five chlorinated butenes and butadienes including trans-1,4-dichlorobutene-2 (1,4-DCB-2), 3,4-dichlorobutene-1 (3,4-DCB-1), 2,3,4-trichlorobutene-1 (2,3,4-TCB-1), chloroprene and DCBD into the groundwater environment. Granular iron has been shown to be effective in the remediation of groundwater contaminated with chlorinated organic compounds by reductive dechlorination. To evaluate the possibility of using granular iron in the remediation of the above contaminants a series of batch and column experiments were conducted at the laboratory scale. Chlorine mass balance calculations showed that each compound, with the exception of DCBD, could be fully dechlorinated by the use of granular iron. Kinetic data and proposed reaction pathways, however, suggest that DCBD can also be fully dechlorinated by granular iron. Normalization of observed pseudo-first-order reaction half-lives indicated that compounds were degrading much slower in batch experiments than in column experiments. This, along with the observation that temperature did not affect degradation in batch experiments, led to the conclusion that mass transport to the iron surfaces was limiting degradation rates in batch experiments. Results showed that the three chlorinated butenes degraded much faster (normalized column half-lives ranged from 1.6 to 5.2 min) than the two chlorinated butadienes (normalized column half-lives ranged from 115 to 197 min). Chlorinated and non-chlorinated intermediates were identified. It was determined that all contaminants degrade to 1,3-butadiene as a reaction intermediate which then degraded to a mixture of non-harmful end products consisting of 1-butene, cis-2-butene, trans-2-butene and n-butane. The reaction pathway from 1,4-DCB-2 to 1,3-butadiene was proposed to be a reductive elimination similar to reductive β-elimination. 3,4-DCB-1 and 2,3,4-TCB-1 were proposed to undergo reductive β-elimination reactions resulting in 1,3-butadiene and chloroprene intermediates, respectively. Degradation of chloroprene and DCBD occurred via hydrogenolysis pathways while 1,3-butadiene underwent catalytic hydrogenation resulting in the observed end products. The results suggest that granular iron may be an effective treatment for groundwater contaminated with these compounds.

Sites where 2-chlorobutadiene-1,3 (chloroprene) and 2,3-dichlorobutadiene-1,3 (DCBD) are synthesized for use in chlorobutyl rubber have the potential to release a mixture of at least five chlorinated butenes and butadienes including trans-1,4-dichlorobutene-2 (1,4-DCB-2), 3,4-dichlorobutene-1 (3,4-DCB-1), 2,3,4-trichlorobutene-1 (2,3,4-TCB-1), chloroprene and DCBD into the groundwater environment. Granular iron has been shown to be effective in the remediation of groundwater contaminated with chlorinated organic compounds by reductive dechlorination. To evaluate the possibility of using granular iron in the remediation of the above contaminants a series of batch and column experiments were conducted at the laboratory scale. Chlorine mass balance calculations showed that each compound, with the exception of DCBD, could be fully dechlorinated by the use of granular iron. Kinetic data and proposed reaction pathways, however, suggest that DCBD can also be fully dechlorinated by granular iron. Normalization of observed pseudo-first-order reaction half-lives indicated that compounds were degrading much slower in batch experiments than in column experiments. This, along with the observation that temperature did not affect degradation in batch experiments, led to the conclusion that mass transport to the iron surfaces was limiting degradation rates in batch experiments. Results showed that the three chlorinated butenes degraded much faster (normalized column half-lives ranged from 1.6 to 5.2 min) than the two chlorinated butadienes (normalized column half-lives ranged from 115 to 197 min). Chlorinated and non-chlorinated intermediates were identified. It was determined that all contaminants degrade to 1,3-butadiene as a reaction intermediate which then degraded to a mixture of non-harmful end products consisting of 1-butene, cis-2-butene, trans-2-butene and n-butane. The reaction pathway from 1,4-DCB-2 to 1,3-butadiene was proposed to be a reductive elimination similar to reductive β-elimination. 3,4-DCB-1 and 2,3,4-TCB-1 were proposed to undergo reductive β-elimination reactions resulting in 1,3-butadiene and chloroprene intermediates, respectively. Degradation of chloroprene and DCBD occurred via hydrogenolysis pathways while 1,3-butadiene underwent catalytic hydrogenation resulting in the observed end products. The results suggest that granular iron may be an effective treatment for groundwater contaminated with these compounds.

Chlorine gas bleaching was a common method used in pulp industries. As a consequence, significant amounts of chlorine were discharged into surrounding aquatic ecosystems, affecting the biota. Chlorinated organic pollutants are formed when chlorine react with organic material. Octadecanoic acid (stearic acid) is one of the most common saturated fatty acids in aquatic biota. In a naturally occurring process two and four chlorine atoms, respectively, are added over the unsaturated bonds, forming 9,10-dichloro octadecanoic acid and 9,10,12,13-tetrachloro octadecanoic acid. These are the chlorinated fatty acids (ClFA) under investigation in this Bachelor’s Thesis. The methodological framework for measuring ClFA is investigated in this essay. The scope is to evaluate the method of isolating and quantifying the compounds as described in Åkesson-Nilsson’s (2004) dissertation. The method includes: extraction of the lipid, transesterification (where the fatty acids, including the ClFAs, are separated from the lipids and transformed into their respective methyl esters through two methods, acidic catalysis with BF3 or H2SO4), separation (by solid phase extraction) and determination of ClFA concentration with a halogen specific detector (GC-XSD/MS). Furthermore, the scope is to investigate collected fish samples (from Norrsundet) with the abovementioned method. By making a dilution series with known concentrations it was possible to establish calibration curves, to give in an indication of the effectiveness of the method. BF3 is in need of updating due to being experienced as slower and less stable than the H2SO4-method. However, it was concluded that the H2SO4-method was more effective on the standard samples and that the BF3-method was more effective on the fish lipid samples. In one of the lipid samples (lavaret transesterified with BF3) a detectable concentration of 9,10,12,13-tetrachloro octadecanoic acid was discovered. Therefore, we question SEPAs decision to cancel investigations in Norrsundet. Our results could indicate that ClFAs are still an issue that could affect the ecosystem’s biota.

This dissertation contains the results of two different projects. The first one is a study of the transport of protozoa pathogens Cryptosporidium parvum and Encephalitozoon intestinalis in soils. The aim of this project was to investigate the movement and retention mechanisms of these microorganisms in natural porous media. The work determined that in the case of C. parvum, the retention was primarily produced by straining and in the case of E. intestinalis the main retention mechanism was attachment. The results of C. parvum lysimeter experiment compared to the results from the 7 cm column experiments suggest that retention is proportional to the length of the column. The second study evaluated the Polymerase Chain Reaction (PCR) as a tool to identify dechlorinating bacteria in groundwater contaminated with chloroethenes. The target DNA regions to identify these microorganism were the 16s rDNA specific for dehalococcoides sp. and Desulfuromonas and DNA sequences coding for the reductive dehalogenase enzymes pceA, tceA, bvcA and vcrA. Bacteria able to transform PCE into DCE were detected in all groundwater samples. Bacteria able to transform VC into ethene were found only in one of the samples. This study shows that PCR analysis of 16s rDNA and reductive dehalogenase gene sequences together with microcosm results are useful tools to analyze the populations of reductive dechlorinators and their activity in a given site.

Site characterization methods for measuring the occurrence, magnitude, and rate of microbial mediated transformation processes were evaluated to assess the implementation of monitored natural attenuation (MNA) at chlorinated ethenes contaminated sites. A model site in Arizona, the Park-Euclid WQARF site in Tucson, was selected for the study. Field, geochemical, and compound specific carbon isotope fractionation (CSI) data confirm intrinsic biodegradation is occurring in the perched aquifer. Use of the BIOCHLOR model and a screening protocol support the potential for reductive dehalogenation found in the perched aquifer. Biotransformation of tetrachloroethene to cis-1,2-dichloroethene (cis-DCE) was achieved in microcosm studies. Transformation of cis-DCE to vinyl chloride and to ethene is, at the moment, the laboratory rate limiting step. PCR analysis established that the aquifer contains Dehalococcoides sp. and other dechlorinating microorganisms, though genes that encode for enzymes capable of achieving complete dehalogenation of the chlorinated contaminants were confirmed only in one monitoring well. The regional aquifer shows little evidence of intrinsic biodegradation. This study corroborates that CSI analysis can be used as an additional line of evidence to evaluate and verify MNA. Microbial analysis provides relevant information about the capabilities of native microbial communities to carry out reductive dehalogenation and thus, to naturally attenuate chlorinated compounds at a contaminated site. The combination of microcosm studies, CSI analysis, and bacterial DNA identification is becoming a convincing line of evidence for the assessment of MNA application to chloroethenes contaminated sites.

Nanosized metal particles have become an important class of materials in the field of catalysis, optical, electronic, magnetic and biological devices due to the unique physical and chemical properties. This research deals with the synthesis of structured bimetallic nanoparticles for the dechlorination of toxic organics. Nanoparticle synthesis in aqueous phase for dechlorination studies has been reported. However, in the absence of polymers or surfactants particles can easily aggregate into large particles with wide size distribution. In this study, we report a novel in-situ synthesis method of bimetallic nanoparticles embedded in polyacrylic acid (PAA) functionalized microfiltration membranes by chemical reduction of metal ions bound to the carboxylic acid groups. Membrane-based nanoparticle synthesis offers many advantages: reduction of particle loss, prevention of particle agglomeration, application of convective flow, and recapture of dissolved metal ions. The objective of this research is to synthesize and characterize nanostructured bimetallic particles in membranes, understand and quantify the catalytic hydrodechlorination mechanism, and develop a membrane reactor model to predict and simulate reactions under various conditions. In this study, the PAA functionalization was achieved by filling the porous PVDF membranes with acrylic acid and subsequent in-situ free radical polymerization. Target metal cations (iron in this case) were then introduced into the membranes by ion exchange process. Subsequent reduction resulted in the formation of metal nanoparticles (around 30 nm). Bimetallic nanoparticles can be formed by post deposition of secondary appropriate metal such as Pd or Ni. The membranes and bimetallic nanoparticles were characterized by: SEM, TEM, TGA, and FTIR. A specimen-drift-free X-ray energy dispersive spectroscopy (EDS) mapping system was used to determine the two-dimensional element distribution inside the membrane matrix at the nano scale. This high resolution mapping allows for the correlation and understanding the nanoparticle structure, second metal composition in terms of nanoparticle reactivity. Chlorinated aliphatics such as trichloroethylene and conjugated aromatics such as polychlorinated biphenyls (PCBs) were chosen as the model compounds to investigate the catalytic properties of bimetallic nanoparticles and the reaction mechanism and kinetics. Effects of second metal coating, particle size and structure and temperature were studied on the performance of bimetallic system. In order to predict reaction at different conditions, a two-dimensional steady state model was developed to correlate and simulate mass transfer and reaction in the membrane pores under convective flow mode. The 2-D equations were solved by COMSOL (Femlab). The influence of changing parameters such as reactor geometry (i.e. membrane pore size) and Pd coating composition were evaluated by the model and compared well with the experimental data.

Västerås is a city with an industrial heritage. One of the larger companies in Västerås is ABB AB, which has multiply businesses located at the area Finnslätten. High concentrations of trichloroethene (TCE) were found in the soil and groundwater at Finnslätten 1 during a phase II environmental site assessment. Due to the result of the assessment a supplementary investigation and a site specific risk assessment were made of building 358. The source zone and plume of trichloroethene have not been characterized even after several investigations at the site. The aim of this study was to make a risk assessment of three other buildings inside the area were degreasing with TCE have historical taken place. The collected information resulted in a risk class 2 of the three objects and shows that the buildings might be potential pre-emission sources of trichloroethene. The second aim contains a comparison between traditional and alternative approaches to enlighten the importance of effective characterization methods. Two potential characterization strategies were chosen; TRIAD approach and CMF approach. The result showed the importance of systematic project planning, dynamic work planning strategy and the use of multiple techniques to form the best “hybrid” during characterization of DNAPL. In order to bring the investigation to a successful conclusion it is of great importance to consider the uncertainties or diminish the uncertainties by collecting essential information.

KB-1 is an anaerobic Dehalococcoides-containing microbial culture used industrially to bioremediate sites impacted with chlorinated solvents. The culture is typically grown at pH 7. However, lower pH is often encountered and therefore the effect of pH was investigated. Both sudden and stepwise decreases in pH from 7 to 6 and 5.5 were investigated over a period of 450 days. An electron balance was also calculated to look at the flow of electrons for dechlorination. More than 95% of the reducing equivalents went towards methanogenesis and acetogenesis. Select microorganisms were compared by quantitative Polymerase Chain Reaction. It was found that lower rates of dechlorination correspond to low Dehalococcoides numbers and that different methanogens were enriched on different electron donors.