PENGARUH PERUBAHAN KONSENTRASI KO-SUBSTRAT TERHADAP POPULASI MIKROORGANISME PEMUTUS ZAT WARNA AZO DI BIOREAKTOR MEMBRAN

Abstrak : Zat warna azo merupakan masalah utama dari limbah yang dihasilkan oleh industri tekstil. Zat warna azo menjadi begitu berbahaya karena sifatnya yang toksik dan mutagenik untuk kehidupan. Untuk menghilangkan zat warna azo pada air buangan, maka dikembangkan strategi baru untuk pengolahan air buangan secara biologi bernama bioreaktor membran (BRM). BRM yang memiliki 3 tangki, yaitu anoksik, kontak, dan stabilisasi, akan beroperasi dengan konsentrasi ko-substrat yang divariasikan, yaitu 2%, 4%, 6%, 8%, dan 10%. Tujuan penelitian ini adalah mengetahui dinamika populasi mikroba yang mempengaruhi proses rekayasa yang terjadi di dalam BRM, seperti penyisihan warna dan zat organik. Parameter yang diukur adalah perubahan populasi mikroba per tangki, identifikasi jenis mikroba dominan, dan pengaruh mikroba terhadap pendegradasian warna dan zat organik. Hasil menunjukkan bahwa pertumbuhan mikroba optimum terjadi di konsentrasi ko-substrat 6%. Mikroba sangat berperan terhadap pendegradasian zat warna azo, terutama mikroba di tangki anoksik. Spesies dominan yang berpengaruh terhadap proses rekayasa BRM diidentifikasi berjumlah 7 spesies.Abstract : The azo dye is the main problem of the waste produced by the textile industries. It is very dangerous to living entities due to its toxicity and mutagenic properties. In order to remove the properties (color) of the azo dye waste when disposing to the water environment, this research developed a new concept using a Biology Treatment Process called as a membrane bioreactor (BRM). BRM has three tanks, which is anoxic, contacts, and stabilization, and it operates with various co-substrate concentrations, namely 2%, 4%, 6%, 8%, and 10%. The purpose of this research is to determine the dynamics of microbial population that affect the engineering process occurs in the BRM, such as azo dyes decolorization and organic matter removal. Parameters being measured are the changes in microbial populations in each tank, the identification of dominant microbial species, and the influence of microbes on color and organic matter removal. Results showed that optimum microbial growth occurred in the co-substrate concentration of 6%. Microbes contribute significantly in azo dyes removal, especially microbes in anoxic tank. There are 7 species identified as dominant species that contribute in the engineering process of BRM.Keywords : azo dyes, membrane bioreactor, microbial growth, microbial identification, the dynamics of microbial populatio

Pollution by Urban Submarine Groundwater Discharge from the Jepara Coastal Region and Its Implications for Local Water Management

Submarine groundwater discharge (SGD) is known to transport terrestrial nutrients and other potential pollutants to coastal areas around the world. However, SGD studies in tropical developing regions, such as Southeast Asia, are scarce, even though this area is hypothesized to be an SGD hotspot due to favorable meteorological and hydrological conditions. Jepara, a coastal city in northern Java, is characterized by a number of environmental and anthropogenic steering factors (e.g., precipitation rates, volcanic geology, coastal population density, and urban land use) that may support the notion of considerable SGD rates and its associated pollutant fluxes. Therefore, this thesis investigates SGD volumetric estimation with nutrient and microbial community composition to analyze the scale of land-based pollutants delivered by SGD to the nearshore water. Additionally, environmental and health impacts of SGD and suggested coastal water management in this region are also discussed. 222Rn was employed as a groundwater tracer in the coastal water to estimate SGD rates. Spatial and temporal 222Rn surveys were conducted in the estuaries and along the coastline of Jepara. The results indicate that terrestrial groundwater was discharged more at the estuaries than at the coastline. Fresh groundwater comprised up to 42% of total river discharge and 40% of total SGD at the coastline. SGD in this area was driven primarily by tidal pumping, with additional hydraulic gradient-driven fresh groundwater discharge at low tide. A combination of estuarine and coastal SGD results in total volumetric SGD rates of 6.6 x 105 m3 d-1. SGD rates in this area were comparable with those of other volcanic SGD studies and were higher than those in other sub-tropical or temperate region studies. SGD was confirmed to deliver terrestrial dissolved inorganic nitrogen (DIN) and dissolved silica (DSi) to the coastal system, and it also potentially acted as one of the landa ocean delivery pathways for fecal indicators and bacterial pathogens. It was also found that salinity and temperature were the most determinant variables that shaped microbial community composition in an SGD cross section. Nutrient and land-use analyses suggest that high nutrient pools in the coastal hydrological system originated from human activities, i.e., agriculture, livestock, and the sewage system. This result was also supported by microbial community analysis, where identification of fecal indicators and potential pathogens in the SGD compartment confirmed the occurrence of biological contamination. Nutrient levels and potential pathogens lead to coastal eutrophication and waterborne illnesses, which were reported from this area. From these observations, it was concluded that suitable coastal water pollution prevention at this study site should include terrestrial nitrogen containment along the riverbank and estuaries (e.g., a constructed wetland or riparian zones) and the development of a sewage system and a centralized wastewater treatment plant. Overall, this thesis shows a significant amount of contaminant discharge in the coastal area via SGD due to a combination of both environmental and anthropogenic factors. Moreover, it can be inferred that a combination of interdisciplinary geoscience research (e.g., hydrosphere, biosphere, anthroposphere) can provide a deeper understanding and assessment of SGD in a specific environment. Even though it is a local study, the methodology and results of this thesis can be replicated and thus provide assistance in other coastal urban cities in tropical regions and hence facilitate better evaluation and monitoring of tropical coastal water ecosystems in the future

Municipal wastewater treatment using salsnes filter and hollow fiber membrane bioreactor (HMFB)

Master's thesis in Environmental technologyThis study investigated the performance of Salsnes Filter (SF) as a primary treatment prior to hollow fiber membrane bioreactor (HFMB) for nitrogen removal. The objective was to determine whether influent particle size removed during primary treatment had any detrimental effect on downstream biological processes, especially nitrogen removal. The pilot scale testing was conducted at Nordre Follo Wastewater Treatment Plant, Oslo region, Norway. This pilot system comprised of two anoxic tanks and one aerobic tank with hollow fiber membrane. Hollow fiber module type ZW-10 was provided by GE Water Technologies. One system was fed with influent wastewater that has been filtered with SF 2 mm and represents the degritted wastewater (treatment Train C), while the other system was filtered specifically with SF 33 μm (treatment Train D). Two boundary conditions were used, the first investigated SF and MBR as the whole system, and the last reviewed the effect of different particle size on the performance of MBR system. For both boundary conditions, it was found that both treatment trains have similar capability in reducing Total Suspended Solids (TSS), Total Chemical Oxygen Demand (TCOD), Total Biochemical Oxygen Demand (TBOD5), and Total Phosphorus (TP) with average removal percentage of 99 %, 92 %, 99 %, and 79 % respectively, which met the discharge requirement criteria. However, Total Nitrogen (TN) effluent results showed that treatment Train C has better average removal efficiency of 73 % compared to treatment Train D’s 68 % due to higher TCOD/TN ratio after SF treatment. Low TCOD/TN ratio in treatment Train D hampered the denitrification process, as confirmed by lower denitrification rate and higher NO3-N concentration in the permeate than its counterpart. Nitrification and denitrification were proven to be the main factor of biological nitrogen removal compared to cell assimilation process. The HFMB operated smoothly during the experiment, with no excessive fouling detected. Membrane in treatment Train C experienced more frequent rapid transmembrane pressure (TMP) peaks due to abundance of organic and organic matters, making it more vulnerable of membrane fouling for long term operation. Overall, both systems produced high quality effluent and free of TSS, even though treatment Train C was susceptible of membrane fouling and treatment Train D had slight problem in its nitrogen removal process. Further economic observation should be implemented to decide which system is more cost effective between the requirement of more frequent membrane maintenance cleaning for treatment Train C or external carbon source addition for treatment Train D

Physiochemical data of submarine groundwater discharge (SGD) samples in Mobile Bay, Alabama

Mobile Bay, the fourth largest estuary in the USA located in the northern Gulf of Mexico, is known for extreme hypoxia in the water column during dry season caused by NH4+rich and anoxic submarine groundwater discharge (SGD). Nutrient dynamics in the coastal ecosystem point to potentially elevated microbial activities; however, little is known about microbial community composition and their functional roles in this area. In this study, we investigated microbial community composition, distribution, and metabolic prediction along the coastal hydrological compartment of Mobile Bay using 16S rRNA gene sequencing. We collected microbial samples from surface (river and bay water) and subsurface water (groundwater and coastal pore water from two SGD sites with peat and sandy lithology, respectively). Salinity was identified as the primary factor affecting the distribution of microbial communities across surface water samples, while DON and PO4^3- were the major predictor of community shift within subsurface water samples. Higher microbial diversity was found in coastal pore water in comparison to surface water samples. Gammaproteobacteria, Bacteroidia, and Oxyphotobacteria dominated the bacterial community. Among the archaea, methanogens were prevalent in the peat-dominated SGD site, while the sandy SGD site was characterized by a higher proportion of ammonia-oxidizing archaea. Cyanobium PCC-6307 and unclassified Thermodesulfovibrionia were identified as dominant taxa strongly associated with trends in environmental parameters in surface and subsurface samples, respectively. Microbial communities found in the groundwater and peat layer consisted of taxa known for denitrification and dissimilatory nitrate reduction to ammonium (DNRA). This finding suggested that microbial communities might also play a significant role in mediating nitrogen transformation in the SGD flow path and in affecting the chemical composition of SGD discharging to the water column. Given the ecological importance of microorganisms, further studies at higher taxonomic and functional resolution are needed to accurately predict chemical biotransformation processes along the coastal hydrological continuum, which influence water quality and environmental condition in Mobile Bay

Verschmutzung durch urbane Submarine Grundwasseraustritte in der Küstenregion von Jepara und die Auswirkungen auf das lokale Wassermanagement

Submarine groundwater discharge (SGD) is known to transport terrestrial nutrients and other potential pollutants to coastal areas around the world. However, SGD studies in tropical developing regions, such as Southeast Asia, are scarce, even though this area is hypothesized to be an SGD hotspot due to favorable meteorological and hydrological conditions. Jepara, a coastal city in northern Java, is characterized by a number of environmental and anthropogenic steering factors (e.g., precipitation rates, volcanic geology, coastal population density, and urban land use) that may support the notion of considerable SGD rates and its associated pollutant fluxes. Therefore, this thesis investigates SGD volumetric estimation with nutrient and microbial community composition to analyze the scale of land-based pollutants delivered by SGD to the nearshore water. Additionally, environmental and health impacts of SGD and suggested coastal water management in this region are also discussed. 222Rn was employed as a groundwater tracer in the coastal water to estimate SGD rates. Spatial and temporal 222Rn surveys were conducted in the estuaries and along the coastline of Jepara. The results indicate that terrestrial groundwater was discharged more at the estuaries than at the coastline. Fresh groundwater comprised up to 42% of total river discharge and 40% of total SGD at the coastline. SGD in this area was driven primarily by tidal pumping, with additional hydraulic gradient-driven fresh groundwater discharge at low tide. A combination of estuarine and coastal SGD results in total volumetric SGD rates of 6.6 x 105 m3 d-1. SGD rates in this area were comparable with those of other volcanic SGD studies and were higher than those in other sub-tropical or temperate region studies. SGD was confirmed to deliver terrestrial dissolved inorganic nitrogen (DIN) and dissolved silica (DSi) to the coastal system, and it also potentially acted as one of the landa ocean delivery pathways for fecal indicators and bacterial pathogens. It was also found that salinity and temperature were the most determinant variables that shaped microbial community composition in an SGD cross section. Nutrient and land-use analyses suggest that high nutrient pools in the coastal hydrological system originated from human activities, i.e., agriculture, livestock, and the sewage system. This result was also supported by microbial community analysis, where identification of fecal indicators and potential pathogens in the SGD compartment confirmed the occurrence of biological contamination. Nutrient levels and potential pathogens lead to coastal eutrophication and waterborne illnesses, which were reported from this area. From these observations, it was concluded that suitable coastal water pollution prevention at this study site should include terrestrial nitrogen containment along the riverbank and estuaries (e.g., a constructed wetland or riparian zones) and the development of a sewage system and a centralized wastewater treatment plant. Overall, this thesis shows a significant amount of contaminant discharge in the coastal area via SGD due to a combination of both environmental and anthropogenic factors. Moreover, it can be inferred that a combination of interdisciplinary geoscience research (e.g., hydrosphere, biosphere, anthroposphere) can provide a deeper understanding and assessment of SGD in a specific environment. Even though it is a local study, the methodology and results of this thesis can be replicated and thus provide assistance in other coastal urban cities in tropical regions and hence facilitate better evaluation and monitoring of tropical coastal water ecosystems in the future