Reaction water, a high-strength COD (chemical oxygen demand) petrochemical effluent, is generated during the Fischer-Tropsch reaction in the SASOL Synthol process at SASOL SynFuels, Secunda, South Africa. Distillation of the reaction water to remove non- and oxygenated hydrocarbons yields approximately 25 - 30 ML/d of an organic (carboxylic) acid-enriched stream (average COD of 16 000 mg/L) containing primarily C2 – C5 organic acids, light oils, aldehydes, ketones, cresols and phenols. Together with the Oily sewer water (API) and Stripped Gas Liquor (SGL) process streams, this process effluent is currently treated in ten dedicated activated sludge basins. However, the successful operation of these activated sludge systems has proven to be difficult with low organic loading rates (3.5 kg COD/m3.d) low COD removal efficiencies (<80 %) and high specific air requirements (60 - 75 m3 air/kg CODrem). It is hypothesised that these operational difficulties can be attributed to organic shock loadings, variation in volumetric and hydraulic loadings, as well as variations in the composition of the various process streams being treated. Due to the fact that the Fischer-Tropsch (Synthol) reaction water constitutes 70 % of the COD load on the activated sludge systems, alternative processes to improve the treatment cost and efficiency of the Fischer-Tropsch acid stream are being investigated. Various studies evaluating the aerobic and anaerobic treatment of Fischer-Tropsch reaction water alone in suspended growth wastewater treatment systems have proven unsuccessful. High rate fixed-film processes or biofilm reactors, of which the fluidised-bed reactors are considered to he one of the most effective and promising processes for the treatment of high-strength industrial wastewaters, could he a suitable alternative. The primary aim of this study was to evaluate the suitability of biological fluidised-bed reactors (BFBRs) for the treatment of Fischer-Tropsch reaction water. During this study, the use of aerobic and anaerobic biological fluidised-bed reactors (BFBR), using sand and granular activated carbon (GAC) as support matrices, were evaluated for the treatment of a synthetic effluent analogous to the Fischer-Tropsch reaction water stream. After inoculation, the reactors were operated in batch mode for 10 days at a bed height expansion of 30% and a temperature of 30 ºC to facilitate biofilm formation on the various support matrices. This was followed by continuous operation of the reactors at hydraulic retention times (HRTs) of 2 days. While the COD of the influent and subsequent organic loading rate (OLR) was incrementally increased from 1 600 mg/L to a maximum of 20 000 mg/L and 18 000 mg/L for the aerobic and anaerobic reactors, respectively. Once the maximum influent COD concentration had been achieved the OLR was further increased by decreasing the HRTs of the aerobic and anaerobic reactors to 24h and 8h, and 36h, 24h and 19h, respectively. The dissolved O2 concentration in the main reactor columns of the aerobic reactors was constantly maintained at 0.50 mg/L. Chemical Oxygen Demand (COD) removal efficiencies in excess of 80 % at OLR of up to 30 kg COD/m3.d were achieved in the aerobic BFBRs using both sand and GAC as support matrices. Specific air requirements were calculated to be approximately 35 and 41 m3 air/kg CODrem for the BFBRs using sand and GAC as support matrices, respectively. The oxygen transfer efficiency was calculated to be approximately 5.4 %. At high OLR (> 15 kg COD/m3.d) significant problems were experienced with plugging and subsequent channelling in the BFBR using GAC as support matrix and the reactor had to be backwashed frequently in order to remove excess biomass. Despite these backwash procedures, COD removal efficiencies recovered to previous levels within 24 hours. In contrast, no significant problems were encountered with plug formation and channelling in the BFBR using sand as support matrix. In general the overall reactor performance and COD removal efficiency of the aerobic BFBR using sand as support matrix was more stable and consistent than the BFBR using GAC as support matrix. This BFBR was also more resilient to variations in operational conditions, such as the lowering of the hydraulic retention times and changes in the influent pH. Both aerobic reactors displayed high resilience and COD removal efficiencies in excess of 80 % were achieved during shock loadings. However, both reactors were highly sensitive to changes in pH and any decrease in pH below the pKa values of the volatile fatty acids in the influent (pKa of acetic acid = 4.76) resulted in significant reductions in COD removal efficiencies. Maintenance of reactor pH above 5.0 was thus an essential facet of reactor operation. It has been reported that the VFA/alkalinity ratio can be used to assess the stability of biological reactors. The VFA/alkalinity ratios of the aerobic BFBRs containing sand and GAC as support matrices were stable (VFNalkalinity ratios of < 0.3 - 0.4) until the OLR increased above 10 kg/m3.d. At OLRs higher than 10 kg/m3.d the VFA/alkalinity ratios in the BFBR using sand support matrix increased to 4, above the failure limit value of 0.3 - 0.4. In contrast the VFA/alkalinity ratios of the BFBR using GAC support matrix remained stable until an OLR of 15 kg/m3.d was obtained, where the VFA/alkalinity ratios then increased to > 3. Towards the end of the study when an OLR of approximately 25 kg/m3.d was obtained the VFA/alkalinity ratios of both the BFBRs using sand and GAC as support matrices increased to 9 and 6 respectively, indicating the decrease in reactor stability and acidification of the process. Total solid (TS) and volatile solid (VS) concentrations in the aerobic BFBRs were initially high and decreased over time. While the total suspended solids (TSS) and volatile suspended solids (VSS) concentrations were initially low and increased over time as the OLR was increased, this is thought to be as a result of decreased HRT leading to biomass washout. The anaerobic BFBR using sand as support matrix never stabilised and COD removal efficiency remained very low (< 30 %), possibly due to the high levels of shear forces. Further studies concerning the use of sand as support matrix were subsequently terminated. An average COD removal efficiency of approximately 60 % was achieved in the anaerobic BFBR using GAC as a support matrix at organic loading rates lower than 10 kg COD/m3.d. The removal efficiency gradually decreased to 50 % as organic loading rates were increased to 20 kg COD/m3.d. At OLRs of 20 kg COD/m3.d, the biogas and methane yields of the anaerobic BFBR using GAC as support matrix were determined to be approximately 0.38 m3 biogas/kg CODrem (0.3 m3 biogas/m3reactor vol.d), and 0.20 m3 CH4/kg CODrem (0.23 m3 CH4/m3reactor vol.d), respectively. This value is 57 % of the theoretical maximum methane yield attainable (3.5 m3 CH4/kg CODrem). The methane yield increased as the OLR increased, however, when the OLR reached 8 kg/m3.d the methane yield levelled off and remained constant at approximately 2 m3 CH4/m3reactor vol.d. Although the methane content of the biogas was initially very low (< 30 %), the methane content gradually increased to 60 % at OLRs of 20 kg COD/m3.d. The anaerobic BFBR using GAC as support matrix determined that as the OLR increased (>12 kg/m3.d), the VFA/alkalinity ratio increased to approximately 5, this is indicative of the decrease in stability and acidification of the process. The anaerobic BFBR using GAC as support matrix experienced no problems with plug formation and channelling. This is due to the lower biomass production by anaerobic microorganisms than in the aerobic reactors. The TS and VS concentrations were lower than the aerobic concentrations but followed the same trend of decreasing over time, while the TSS and VSS concentrations increased due to decreased HRTs. The anaerobic BFBR was sensitive to dramatic variations in organic loading rates, pH and COD removal efficiencies decreased significantly after any shock loadings. Compared to the activated sludge systems currently being used for the biological treatment of Fischer-Tropsch reaction water at SASOL SynFuels, Secunda, South Africa, a seven-fold increase in OLR and a 55 % reduction in the specific air requirement was achieved using the aerobic BFBRs. The methane produced could also be used as an alternative source of energy. It is, however, evident that the support matrix has a significant influence on reactor performance. Excellent results were achieved using sand and GAC as support matrices in the aerobic and anaerobic BFBRs, respectively. It is thus recommended that future research be conducted on the optimisation of the use of aerobic and anaerobic BFBRs using these support matrices. Based on the results obtained from this study, it can be concluded that both aerobic and anaerobic treatment of a synthetic effluent analogous to the Fischer-Tropsch reaction water as generated by SASOL in the Fischer-Tropsch Synthol process were successful and that the application of fluidised-bed reactors (attached growth systems) could serve as a feasible alternative technology when compared to the current activated sludge treatment systems (suspended growth) currently used. Keywords: aerobic treatment, anaerobic treatment, biological fluidised-bed reactors, petrochemical effluent, Fischer-Tropsch reaction water, industrial wastewater. / Thesis (M. Omgewingswetenskappe)--North-West University, Potchefstroom Campus, 2004.

The present study aimed to investigate the methane yield from anaerobic digestion of a lignocellulosic substrate subjected to different pretreatments. The lignocellulosic forest residues materials were milled and then pretreated with the organic solvent NMMO (N-Methylmorpholine N-oxide) and/or the lignolytic enzymes laccase and versatile peroxidase at a dosage of 60 U g-1 total solids (TS) substrate. The amount of methane produced was studied in a biomethane potential assay with inocula from a thermophilic biogas reactor treating municipal waste. All samples were run in triplicates. Due to the large amount of samples, two biomethane potential assays were conducted: series 10 &amp; 20 and series 30 &amp; 40. The gas production results show that NMMO-treated forest residues yielded 130 NmL CH4 g-1 volatile solids (VS) substrate and the untreated forest residues yielded 95 NmL CH4 g-1 VS substrate for series 10 &amp; 20. For series 30 &amp; 40, both untreated and NMMO-treated forest residues yielded 140 NmL CH4 g-1 VS substrate. NMMO-treatment appears to be favourable and no advantages from the enzyme pretreatment could be seen in terms of gas yield. An analysis of the reaction fluid after the enzymatic treatment showed presence of phenols, an indication of successful lignin hydrolysis. / Studien avsåg att undersöka metanutbytet från anaerob nedbrytning med förbehandlad lignocellulosa som substrat. Lignocellulosamaterialet, i form av skogsavfall, maldes och förbehandlades därefter med det organiska lösningsmedlet NMMO (N-metylmorfolin-N-oxid) och/eller de lignolytiska enzymerna laccase och versatile peroxidas med dosen 60 U g-1 torrsubstanshalt (TS). Mängden producerad metan undersöktes i en biometanpotentialanalys med inocula från en termofil biogasreaktor, som behandlade hushållsavfall. Triplikat av varje prov användes för att öka den statistiska stabiliteten. På grund av det stora antalet prover genomfördes studien i två omgångar: Serie 10 &amp; 20 samt serie 30 &amp; 40. Resultaten visade att det NMMO-behandlade skogsavfallet gav 130 NmL CH4 g-1 organisk substans (VS) och det obehandlade skogsavfallet gav 95 NmL CH4 g-1 VS i serie 10 &amp; 20. Både obehandlat och NMMO- behandlat skogsavfall gav 140 NmL CH4 g-1 VS i serie 30 &amp; 40. Förbehandling med NMMO verkar vara fördelaktig medan enzymbehandling endast resulterade i en smärre ökning av gasproduktionen. En analys av vätskan efter enzymbehandlingen visade förekomst av fenoler, vilket visar på en lyckad ligninnedbrytning.

Hypothesis. Heterochronicity of body functions reveals itself during the performing different movement tasks, in particular at onset of the exercise or in changing the parameters of the load as well as during the recovering period. We think that estimations of body functional state of the sportsmen can better reflect manifestations of complexity of body functioning during the physical loads tries join different movement tasks: a dosed aerobic load and a maximum effort anaerobic load try. In order to verify this hypothesis it is purposeful to estimate peculiarities of functional state change and long-term adaptation effects due to concentrated physical loads of different direction. The aim of the research: to define how the functional state of subjects adapted to speed-power physical loads is affected by concentrated aerobic and anaerobic type loads by using various assessments of sportsmen functional state. CONCLUSIONS 1. Subjects adapted to speed-power physical loads distinguish themselves by the higher indices of muscles working-capacity by performing maximum short-term effort requiring tasks than non-athletes or the subjects adapted to endurance physical loads. From the standpoint of central nervous system functional state indices they distinguish themselves by greater central nervous system mobility and smallest central nervous system functional stability values. Speed-power representatives distinguish themselves by lower cardiovascular system indices related to... [to full text]

Subject of the study. Aerobic capacity and cardiac structure and function of healthy young males. Background. Data regarding the relationship between the parameters of aerobic capacity (such as maximal oxygen uptake or anaerobic threshold) and cardiac structure as well as function remain sparse and controversial. Aim. To determine how the parameters of aerobic capacity are correlated with those of cardiac structure and function. Objectives: 1. To determine the correlation between anaerobic thresholds and myocardial structure. 2. To determine how strongly the maximal oxygen uptake and cardiac structure are correlated. 3. To determine the correlation of indices of aerobic capacity to the parameters of myocardial function at rest. Hypothesis. Cardiac structure and function of healthy young men is directly linked not only to maximal oxygen uptake but anaerobic thresholds as well. Conclusions. The direct correlation of the parameters of concentric cardiac hypertrophy with aerobic capacity (anaerobic thresholds as well as maximal oxygen uptake) indices was detected. However, we failed to detect a significant correlation between indices of eccentric cardiac hypertrophy or myocardial function and aerobic capacity.

The objective of this study was to determine sprint athletes and non–athletes girls acute muscles and heart adaptation peculiarities to multiple anaerobic loads. The study‘s participants were girls of similar age: 5 trained athletes in sprint events and 5 non–athletes. There were estimated their antropometric parametres, assessed body mass index (BMI) and heart rate at rest. Also participants performed multiple anaerobic workloads. The results of this research showed that girls well–trained athletes managed to perform greater extent of physical load, were less tired and managed faster to recover between reiterations. The non–athletes performed significantly lower extent of physical load and before the third workload their heart rate‘s indices and results of running 10 m distance with 10 % of body mass weighting indicated considerable fatigue. In consideration of long term adaptation effect we propose, that well–trained athletes have lower body mass, BMI, heart rate at rest, higher running velocity and greater increase of velocity compare to non–athletes. Eaqual duration, intensity, rest pauses and the number of reiterations with and without weighting have different effect on muscle working ability. Athletes showed greater running velocity and it remained unaltered during reiterations in performing eaqual workload without weighting. Participants reached lower velocity and there were obtained velocity reduction in performance with weighting.

Work purpose – to determine permanent quickness and power manual loads influence on skeleton muscle anaerobic potential. 11 of the best Lithuanian short distance runners and 8 persons, who do not go in for sports, were attending in research. Also, there were used adequate testing results and trainings processes information of 8 world short distance runners. They took anthropometrical information measurements from researched, body mass index was estimated (BMI), maximum and comparative legs muscles power was assessed, maximum running and 60m drubbing speed measured. Gained results showed that the best world short distance runners reached better maximum running speed, but maximum and comparative muscles power indicators were not differ from Lithuanians short distance runners. Persons, who do not go in for sports, maximum and relative powers and maximum running speed meaning in worse than researched Lithuanian short distance runners, who go in for sports. When they were running 60m only 10m they were going faster than the best world short distance runners. Persons, who do not go in for sports run 60m distance slower than other researched group members. They also reached slower speed increase and after 50m they got tired. When the best Lithuanian short distance runners of annual training facts were analyzed then came out that in annual training cycle was applied more exercises which needed power and had higher power indicators. Thus, Lithuanian short distance runners faster run 6... [to full text]

The work is directed for one of alternative energy resources – renewable sources of energy. The main task is to examine potential produce biogas out of maize silage. The object of analyses was a biogas plant operated on different organic wastes in the pigs farm of UAB “Lekeciai”. The technologies of biogas production and energy input were analysed in this work. Acording to empirical equations there were developed an estimation methodology of energy consumption in biogas plant. A Energy consumption of technological equipment and energy consumption of maize silage has been investigated and determined. Energetic potential of maize silage have been investigated during experiments. Energetic efficiency of biogas plant given different composition of organic wastes has been determined. Have been estimated efficient of producing biogas out of silage maize.

Tyrimo tikslas – nustatyti įvairaus amžiaus ir lyties orientacininkų kojų tiesiamųjų raumenų galingumą ir atsparumą nuovargiui vertikalaus šuoliavimo testo metu. Buvo ištirti 92 orientacininkai, pagal amžių (metais) ir lytį (moteriška, M; vyriška, V) suskirstyti į šešias grupes: M15–17 merginos (n = 19), M18–20 merginos (n = 9), M>21 moterys (n = 4), V15–17 jaunuoliai (n = 21), V18–20 vaikinai (n = 18), V > 21 vyrai (n = 21). Vertikalių šuolių aukštį matavome pagal C. Bosco metodiką. Po standartinės pramankštos tiriamieji ant 60x60 cm dydžio kontaktinio kilimėlio atliko po tris vienkartinius maksimalių pastangų vertikalius šuolius su rankų mostu ir be mosto, o paskui 60 s šuoliavo maksimaliomis pastangomis, amortizuojamai pritūpdami iki 90° kampo per kelius (rankas laikydami ant juosmens). Vienkartinio vertikalaus šuolio aukštis (taigi ir kojų tiesiamųjų raumenų galingumas) nepriklausė nuo amžiaus, tačiau visose amžiaus grupėse vyriška lytis tiriamieji pašokdavo aukščiau. Lyginant orientacininkių gebėjimą aukštai pašokti su rankų mostu ir be mosto, reikšmingus pašokimo aukščio skirtumus nustatėme 15–17 ir 18–20 metų amžiaus orientacininkių grupėse, o tarp orientacininkų šis skirtumas buvo reikšmingas visose amžiaus grupėse (p < 0,001). Išanalizavę šuolių aukščio kaitą 1 min. šuoliavimo testo metu pastebėjome, kad statistiškai reikšmingi vargstamumo skirtumai amžiaus aspektu buvo tik tarp M15–17 ir M18–20 grupių (p < 0,05), o lyties aspektu – tarp M15–17 ir V15–17 grupių... [toliau žr. visą tekstą] / The aim of the study was to estimate vertical jumping performance in orienteers of various age and both sexes. The study embraced 92 orienteers of national level. According to age (years) and gender (males, M; females, F), six groups of athletes were singled out: F15–17 (n = 19), F18–20 (n = 9), F>21 (n = 4), M15–17 (n = 21), M18–20 (n = 18), and M>21 (n = 21). After a standard warm-up, subjects performed maximal intensity vertical jumps on the contact mat sized 60x60 cm. After orienteers made jumps with and without arm swing (3 attempts each), all-out vertical jumps for 60 sec with a shock-absorbing squat to 90° knee angle, arms akimbo, were performed. The jump height was measured according to C. Bosco et al., using a flight-phase time as a sole indicator. There were no statistically significant differences in the height of the single vertical jump between age groups, irrespectively of the gender. However, statistically significant differences were observed in the height of the single vertical jump in all age groups in respect to gender. The comparison of vertical jumps performed by females with and without arm swing revealed statistically significant difference only between F15–17 and F18–20 groups, while the difference in jump height between two modes was statistically significant in male orienteers of all age groups (p < 0.001). F15–17 and F18–20 groups differed in respect to fatigue index during 60 sec test (p < 0.05). The different fatigue index was observed in respect... [to full text]

Baigiamajame magistro darbe nagrinėjamas mažo negilaus humusinio ežero, kuris tapo meromiktiniu dar prieš Černobylio avariją, užterštumas radioceziu. Tyrimai parodė, kad ežeras yra sudarytas iš dviejų atskirų baseinų. Viršutinė ežero dalis (iki 3 m gylio) tampa visiškai aerobine tik rudenį, kai ežere vyksta gravitacinis maišymasis. Ežero dugno nuosėdos žemiau kaip 3 m gylio anaerobiniame nesimaišančiame baseine užterštos radioceziu tik dėl branduolinio ginklo bandymų iškritų. Aukštesnis ežero baseinas yra papildomai užterštas radioceziu dėl įvykusios Černobylio avarijos. / Peculiarities of radiocesium contamination of a small shallow humic lake, which became meromictic before the Chernobyl accident, are examined. It is shown that the lake consists of two separate basins. Radiocesium load of the sediments below the 3-m depth in the anaerobic stagnant water part of the lake is mainly formed by nuclear weapons fallout. That load of the upper water basin is significantly larger due to additional contamination after the Chernobyl accident.

Anaerobinis dumblo pūdymas - tai procesas, kurio metu dalis biomasėje esančių organinių junginių dėl įvairių rūšių mikroorganizmų veiklos yra suardomi. Vykstant šiam procesui, irstančios organinės dalelės verčiamos į biodujas – atsinaujinantįjį energijos šaltinį. Tačiau anaerobinis dumblo pūdymas gali sutrikti dėl įvairių inhibitorinių medžiagų. Norint reikiamą nuotekų išvalymo laipsnį užtikrinti pagal bendrąjį fosforą, naudojamas cheminis fosforo šalinimo būdas, kurio metu į nuotekas įterpiamos Al arba Fe metalų druskos. Šio darbo tikslas ‒ nustatyti, kaip skirtingos aliuminio ir geležies koncentracijos veikia anaerobinio stabilizavimo procesą ir išgaunamų dujų kiekį. Darbui atlikti buvo naudojamas standartinis anaerobinio pūdymo W8 (Armfield Ltd, UK) modelis. Tyrimu nustatyta, kad pūdant dumblą, į kurį buvo dozuota Fe druska, išsiskyrusių biodujų kiekis ml/d buvo artimas kontrolinio pūdytuvo reikšmėms, o pūdant dumblą, į kurį buvo dozuotos Fe ir Al druskos, biodujų ml/d išsiskyrė iki 30 % daugiau, nei palyginus su dumblu, į kurį druskos nebuvo dozuotos. Dozuojant metalų druskas ir esant padidėjusiai pūdytuvo apkrovai bepelenėmis sausosiomis medžiagomis, taip pat buvo nustatyta, kad sumažėja bepelenių sausųjų medžiagų suskaidymo efektyvumas iki 5—12 %. Nepaisant sumažėjusio bepelinių sausųjų medžiagų suskaidymo, biodujų m3/kgBSM suskaidytų padidėjo net iki 43 % pagal vidutines reikšmes. Išanalizavus tyrimų rezultatus pateiktos išvados ir rekomendacijos. Darbą sudaro šios... [toliau žr. visą tekstą] / Anaerobic sludge digestion is a process in which part of organic compounds existing in biomass are destroyed of various microorganisms. In this process volatile solids (VS) are converted into biogas – renewable energy source. Anaerobic digestion can be impaired in presence of inhibitors. Chemical phosphorus removal when Al and Fe metals salts are added to wastewater is used to reach the degree of waste water treatment by total phosphorus. Objective of this work was to investigate impact of different aluminium and iron doses on anaerobic digestion process and biogas produced. The work was carried out using standard anaerobic digestion model W8 (Armfied Ltd. UK). Research showed that biogas produced from Fe-dosed sludge was close to biogas production from un-dosed sludge and during digestion of Al-Fe-dosed sludge biogas ml/d production was 30% higher that from control. The efficiency of volatile solids destruction decreased 5-12% during dosing of metal salts. Biogas production from VS destructed was approx. 43% higher by average values when metal salts were dosed into sludge. The composition of biogas was not measured during research. Conclusions and recommendations are presented.