A Study Of Landfill Leachate Treatment By Pacl, Sago Starch And Tapioca Starches, Hymenocallis Liriosme And Aloe Vera As Coagulants

The properties and mechanism of reaction of tapioca starch, sago starch, Hymenocallis liriosme and Aloe vera potential in landfill leachate treatment has not yet been fully discovered and examined. Thus this study aims to determine the optimum dosage of PACl, tapioca starch, sago starch, Hymenocallis liriosme, Aloe vera and pH in the removal of COD, NH4-N, colour and SS for treating landfill leachate. Zeta potential for each coagulant used is measured and the capability of sago starch, tapioca starch, Hymenocallis liriosme and Aloe vera act as coagulant aids in reduce the dosage of PACl as coagulant is estimated. The sample of leachate is taken from PBLS. Four main parameters were studied including suspended solid, colour, chemical oxygen demand (COD), and ammoniacal nitrogen (NH4-N). Determination of zeta potential also was done for raw sample, and after coagulation using PACl and other four types of natural coagulants. Results indicated that the optimum dosage for PACl in landfill leachate treatment is 7200mg/L at pH 7.5. The dosage of PACl successfully reduce up to 62.5% in the assisted of sago starch as coagulant aid. While for tapioca starch, it reduces the PACl dosage up to 40%. For the green plants, Hymenocallis liriosme and Aloe vera, they show the capability in reduce the PACl usage up to 75% respectively. Among these natural coagulants, Hymenocallis liriosme and Aloe vera show highest capability as coagulant aids in reduce the dosage for PACl as coagulant. Composition and the structural of Hymenocallis liriosme and Aloe vera need for further investigation to obtain the higher pollutant removal efficiency. More quantitative research is necessary to get a better result for this study. Further research focused on the quantitative aspects of the coagulants studied would provide comparative data and more reliable results

Renovation of wastewater for direct re-use in an abattoir

Tertiary treatment methods were tested on secondary effluent from an abattoir biological wastewater treatment plant with the purpose of renovating it for re-use in the abattoir. The colour and dissolved organic matter could be removed to such an extent that the water would comply with water of insignificant health risk (Department of Health). The treatment process sequence proven to be effective in upgrading this water so insignificant health risk standard were coagulation with a polymer blend, separation, ozonation, filtration and activated carbon filtration. The development of biologically activated carbon in practice was accepted as inevitable and desirable for optimum water quality, but not tested. A deciding factor in the selection of an appropriate treatment was that the final water would also have acceptable corrosion properties.Dissertation (MSc)--University of Pretoria, 2010.Chemical Engineeringunrestricte

Robust natural organic matter removal from Scottish water sources of variable DOC content.

Natural organic matter (NOM) is found ubiquitously in raw water and is known to react with the chlorine used in water treatment to produce disinfection by-products (DBPs), some of which are potentially harmful to human health due to their links with cancers. Trihalomethanes (THMs) and haloacetic (HAAs) acids are the two types of carbonaceous DBPs widely regulated. The THMs and HAAs are widely regarded as being good indicators of the presence of the more than 500 other DBPs that have been found in treated drinking water. At large and medium sites in Scotland, the coagulation- flocculation process has long been the main control barrier for removal of the precursors for DBPs. At small sites, ultra and nano filtration membrane filtration processes have been considered a good solution due to their small footprint requirement and large volume of water output. In addition, granular activated carbon (GAC) filtration has long been employed for removal of organic matter. However, increases in the organic content of raw waters, stricter regulatory requirements and concerns over coagulant cost and availability have driven the reconsideration of how NOM laden water sources in Scotland are treated. This thesis investigated the approaches required to increase the robustness of drinking water supply to mitigate against these factors. A stronger correlation was found between commonly measured water quality parameters and DBPs in raw water sources compared to treated water, which was as a result of the lower hydrophobic content of the latter. However, the DBP removal as a function of DOC reduction was calculated and revealed coagulation using ferric sulfate in the pH 4-5-5-5 range as the most feasible solution at large and medium sites. The use of GAC media with high pore uniformity would be appropriate at large or medium sited where up to 50% DOC reduction would be sufficient to control DBPs. At small sites, the tighter pore size membranes showed improved THM precursor removal, whilst most of these maintained a throughput of within 90% of the current membranes.Engineering and Physical Sciences (EPSRC)STREAM EngD Programm

Impact of Coagulation and Ozonation Pretreatment on Ceramic Microfiltration

Globally drinking water sources are under pressure. In many places, there is unintended closure of the water cycle. This means that the wastewater treatment plant effluent with all its pollutants ends up in the source of drinking water treatment plants that are not designed to treat this type of water. Impacts on water sources from factors such as climate change and high population density make unintended reuse, indirect reuse, and potable reuse more accepted and explored. Known reuse schemes use high end treatment technologies such as ceramic microfiltration. While ceramic microfiltration is a beneficial treatment option, its effectiveness can be limited due to membrane fouling causing increases in energy consumption, increases in operating costs, and a loss in permeability. Coagulation and ozonation are pretreatment options that can help mitigate membrane fouling. Using a secondary wastewater effluent reuse pilot at RWZI Wervershoof in the Netherlands, this research project evaluated the abilities of coagulation and ozonation pretreatment to improve ceramic microfiltration performance in comparison with control runs without pretreatment. This evaluation was based on performance parameters such as critical flux and sustainable flux based on a transmembrane pressure (TMP) criterion. Critical flux was defined as the flux level at which the detection of membrane fouling initially appeared, and sustainable flux was defined as the flux level directly (25 Lmh) below the critical flux. Water quality samples were analyzed on NOM characteristics to explain ceramic microfiltration fouling Twenty-four-hour constant flux tests were performed to determine the critical and sustainable fluxes for the three treatment options. For the coagulation pretreatment tests, two dosages of ferric chloride, 20 and 6 mg/L as Fe3+, were tested to determine the more appropriate dosage to restrict ceramic microfiltration fouling. Based on the constant flux test results, a ferric chloride dosage of 6 mg/L as Fe3+ was chosen. For the ozonation pretreatment tests, a bench-scale ozone uptake test was conducted to determine the ozone dosage for the constant flux tests. Based on this test, the selected ozone dosage was 8 mg/L as O3. Without pretreatment, the critical flux was 145 Lmh. Coagulation and ozonation pretreatment increased the critical flux to 195 and 270 Lmh, respectively. During coagulation pretreatment, the critical flux increase was based on NOM removal. During ozonation pretreatment, the critical flux increase was based on changing the NOM characteristics. The results illustrated that compared to no pretreatment, coagulation pretreatment improved and ozonation pretreatment strongly improved ceramic microfiltration performance. Overall, coagulation or ozonation pretreatment enables a more economical application of ceramic microfiltration for water reuse

Selective denitrification by peroxidation of 4-nitrophenol using Janus-structured amphiphilic carbon nanotubes

Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do ParanáIndustrial pollution has grown a lot in recent times, mostly formed by oily compounds, affecting not only the environmental but also human health. As the concern increases, so does the search for effective treatment, a few years the use of different nanostructure porous carbon materials are being used in catalysis. Therefore, in this work carbon nanotubes (CNTs) were tested as catalysts in the selective denitrification of oily wastewater containing 4-nitrophenol (4-NP) by catalytic wet peroxide oxidation (CWPO). The CNTs were prepared by chemical vapor deposition, feeding sequentially ethylene (E) and/or acetonitrile (A) during different times until 20 min, resulting in samples E20, E15A5, E10A10, E5A15, E1A19 and A20, the number denoting the time feeding of each precursor and the order of appearance of the letter indicating the order of each precursor. The synthesized CNTs were tested in the CWPO of 4-NP in aqueous solutions and in simulated oily wastewater (2,2,4-trimethylpentane and water) at 80 ºC, initial pH = 3.5, C4-NP = 1 g/L, CH2O2 = 3.56 g/L, and Ccatalyst = 2.5 g/L. The catalysts A20, E1A19 and E5A15 promoted a faster decomposition of H2O2 and a lower degradation of 4-NP in the aqueous system, whereas the catalysts E20, E15A5 and E10A10 (more hydrophobic character than previous ones) displayed the opposite trend, since E20 was able to remove 99% of the pollutant and A20 only 69% after 8 h of reaction. E15A5 and E10A10 catalysts were able to remove 100% of 4-NP after 24 h of reaction. In biphasic L-L media all catalysts presented a great conversion of 4-NP after 24 h of reaction. E15A5, E10A10 and E1A19 catalyst allow to completely remove 4-NP and E5A15, A20 and E20 led to obtain a removal of 99%, 99% and 98%, respectively. Besides that, the aromaticity was also measured for comparation of materials. The lower concentration of aromatic intermediates was obtained E15A5 and E10A10 (126.34,249.10 mg/L, respectively), and lower pH (2.42, 2.38, respectively), which supports the formation of carboxylic acids. The highest removals conversions obtained with E15A5 and E10A10 is ascribed to the capacity to stabilize Pickering emulsions by E15A5 and E10A10. The amphiphilic characteristic of this material ensures a closer contact between the liquid phases, allowing higher mass transfer.A poluição industrial cresceu muito nos últimos tempos, em sua maioria essa poluição é formada por compostos oleosos, afetando não apenas o ambiente, mas também a saúde humana. À medida que a preocupação aumenta também aumenta a busca por tratamentos eficientes. Há alguns anos o uso de diferentes matérias de carbono poroso nano estruturados estão sendo utilizados na catálise. Portanto, neste trabalho os nanotubos de carbono foram testados como catalisadores na oxidação seletiva de 4-nitrofenol (4-NP) presente em águas residuais oleosas por oxidação catalítica com peróxido de hidrogénio. Os nanotubos de carbono foram preparados por deposição química em fase vapor, alimentando sequencialmente etileno (E) e/ou acetonitrila (A) durante diferentes tempos até 20 min cada um, resultando nas amostras E20, E15A5, E10A10, E5A15, E1A19 e A20, o número denotando o tempo de alimentação de cada precursor e a ordem de aparecimento da letra indicando a ordem de cada precursor. Os nanotubos de carbono sintetizados foram testados no CWPO do 4-NP em soluções aquosas e em águas residuais oleosas simuladas (2,2,4-trimetilpentano e água) a 80 ºC, pH inicial 3,5, C4-NP = 1 g/L, CH2O2 = 3,56 g/L, e CCatalisador = 2,5 g/L. Os catalisadores A20, E1A19 e E5A15 promoveram uma decomposição mais rápida de H2O2 e uma menor degradação de 4-NP no sistema aquoso, enquanto os catalisadores E20, E15A5 e E10A10 (com um caráter mais hidrofóbico que os anteriores) apresentaram tendência oposta, uma vez que, E20 foi capaz de remover 99% do poluente e A20 apenas 69% após 8 h de reação. Os dois catalisadores capazes de remover 100% de 4-NP após 24 h de reação foram E15A5 e E10A10. Em meio L-L bifásico todos os catalisadores apresentaram uma alta conversão de 4-NP após 24 h de reação, E15A5, E10A10 e E1A19 com 100%, E5A15 e A20 com 99% e E20 com 98%. Além disso, a aromaticidade também foi medida para comparação de materiais. Os catalisadores que apresentaram concentração mais baixa dos intermediários aromáticos foram E15A5 e E10A10 (126,34, 249,10 mg/L, respectivamente), e o pH mais baixo também (2,42, 2,38, respectivamente), isso apoia a ideia da formação de ácidos carboxílicos. Esta tendência de melhores resultados pode ser atribuída à formação de emulsões Pickering pelos materiais E15A5 e E10A10. A característica anfifílica desses materiais garantem um contato mais próximo entre as fases líquidas, permitindo maior transferência de massa

Nucleation, milk and membranes as modifications to enhance biological phosphorus removal in activated sludge

Enhanced biological phosphorus removal (EBPR) was researched from the performance of a modified University of Cape Town (UCT), anaerobic-anoxic/nitrifying-aerobic process. The work focussed on high P influent where milk was compared to carbohydrates as exogenous added carbon and typical settled sewage. The results confirmed that at equal COD load in the influent (minimum COD:P (250:5) ratio for EBPR), milk always provided sufficient soluble substrate than the carbohydrate mix, but also improved the EBPR performance. The laboratory scale treated 10L/day where 2 parallel treatment trains for milk and an equivalent carbohydrate mix as supplement to compare and study the P sequestration from hypothesised P ligands in milk and easily assimilable carbon (AOM) after fermentation for biological P uptake. The aerobic bioreactors used submerged flat sheet membranes (AeMBR) to improve the effluent quality and reduce the suspended solid residues. The results suggested extra benefits from adding calcium chloride (CaCl2) (200 ml at 250 mM/day or 200 mg/L treated) to form P complexes both in the anaerobic and aerobic zones (100 ml CaCl2 250mM/zone/day). To complete P removal a calcium phosphate (CaPO4) further treatment stage (post membrane final effluent (F.E.)) was added for nucleation. The combination of, A2O-N, exogenous carbon and calcium addition improved the performance of the EBPR, and enabled the laboratory units to achieve less than the 1 mg/L P required by the EU Directive. The process was tested at higher than normal P loads (maximum 100 mg/L) (domestic wastewater influent 15 mg/L). Experiments with influent P load ≤50mg/L, with 1% milk as AOM were compared to the carbohydrate mix and could remove soluble P to less than 1mg/L above 97% and less than 2 mg/L more than 99% of the in the time respectively. With an influent P load of 60mg/L (maximum 100 mg/L), the soluble P in the F.E. with milk was below 5 mg/L and below 8 mg/L with carbohydrates mix. The results showed that most of the phosphorus was retained by the sludge during the anoxic-aerobic phases. The remaining phosphate in the F.E. was able to pass through AeMBR pore size (0.4 μm) and needed to be chelated by the nucleation process. The results indicated this A2O-N modifications achieved stable nutrient removal and also offered the potential for more sustainable phosphorus recovery. The EBPR without AOM was 25% less efficient compared to milk and never achieved the E.U standard of 1mg/L in final effluent. The flat sheet membrane always achieved a NTU final effluent below 1 and the TOC always greater than 90% removal or less than the EU 125 standard regardless of the feeding COD/P ratio

Avaliação da biomassa obtida pela otimização da flotação de efluentes da indústria de carnes para geração de energia

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Química.A indústria de processamento de carnes gera uma grande quantidade de efluentes líquidos com elevada concentração de poluentes, necessitando de tratamentos de alta eficiência para a minimização dos impactos ao meio ambiente