• Journal of Korean Society on Water Environment
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• v.21 no.5
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• pp.490-495
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• 2005

Since there are very limited numbers of thermophilic anaerobic digesters being operated, it is often difficult to start up a new one using sludge from an existing reactor as a seed. However, for obvious reasons it seems few attempts have been made to compare the start-up performance of thermophilic anaerobic digestion using different sources of seed sludges. The purpose of this study was to evaluate the start-up performance of anaerobic digestion using aerobic Waste Activated Sludge (WAS) from a plant and mesophilic Anaerobic Digested Sludge (ADS) as the seed source at both mesophilic ($35^{\circ}C$) and thermophilic ($55^{\circ}C$) temperatures. In this study, two experiments were conducted. First, thermophilic anaerobic reactors were seeded with WAS (VSS = 4,400 mg/L) and ADS (VSS = 14,500 mg/L) to investigate start-up performance with a feed of acetate as well as propionate. The results show that WAS started to produce $CH_4$ soon after acetate feeding without a lag time, while ADS had a lag time of 10 days. When the feed was changed to propionate, WAS removed propionate down to below the detection limit of 10 mg/L, while ADS removed little propionate and produced little $CH_4$. Second, in order to further compare the methanogenic activity of WAS and ADS, both mesophilic and thermophilic reactors were operated. WAS acclimated to anaerobic conditions shortly and after acclimating it produced more $CH_4$ than ADS. WAS at mesophilic temperature biodegraded acetate at the same rate as for thermophilic. However WAS at mesophilic temperature biodegraded propionate at a much faster rate than at thermophilic. WAS as the seed source of anaerobic digestion resulted in much better performance than ADS at both mesophilic and thermophilic temperatures for both acetate and propionate metabolism.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.11
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• pp.803-808
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• 2013

The purpose of this study was performed to investigate the optimum conditions of pH, concrete sludge, seed dosage, mixing intensity, operation time in treating fluoride-containing wastewater as $CaF_2$ using the ready-mixed concrete sludge. Considering fluoride removal, water content, that pH 6, concrete sludge dosage of 10 g/L, Seed dosage ($CaF_2$) of 2 g/L, mixing intensity of 100 rpm and operation time of 60 min were found to be optimum. Correspondingly, removal of fluoride and water content was about 85% and 64%, respectively. Increase in amount of seed dosage did not affect fluoride removal efficiency. but the result that the water content is decreased was shown up in occuring the solid-liquid separation well.

• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.300-307
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• 2006

The combined SHARON (Single reactor system for High ammonium Removal Over Nitrite)-ANAMMOX (Anaerobic ammonium oxidation) reactor were operated in mesophilic condition ($35^{\circ}C$). In this study, microbial granulation and characteristics of SHARON and ANAMMOX sludges were investigated using settling test, Scanning Electron Microscopy (SEM) and Fluorescence In Situ Hybridization (FISH). In SHARON reactor, Aerobic granulation with diameter of 1.5~2.5 mm was accomplished but aerobic granulation was weaker than anaerobic granular sludge. Initial seed sludge of ANAMMOX reactor was used as attached media for biofilm growth. ANAMMOX sludge was more compact and rounder rather than seed sludge. Though ANAMMOX sludge has high activity, it has lower settling ability than the seed granule. The color of ANAMMOX sludge was changed from dark to redish brown granular with diameter of 1~2 mm. In FISH of ANAMMOX sludge, high fraction of Candidatus B. stuttgartiensis which paid great role of nitrogen conversion was detected. Also, FISH results reveals that ANAMMOX bacteria inhabit at inner parts near surface, having advantages in utilization of substrates and protection from oxygen inhibition.

• Asian Journal of Turfgrass Science
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• v.5 no.2
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• pp.81-86
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• 1991

The sludge, a waste of brewery industries, was examined for potentials as a natural organic fertilizer (or soil conditioner) for lawn. Trial products were measured for changes of physical, chemical properties in laboratory and seed germination and seedling growth in green house were also tested. The results are as the following:1The sludge from distilled liquor brewery contained high quantity of organic matter which had proper physical and chemical properties for lawn fertilizer (natural organic fertilizer, soil conditioner, top-dressing mix) . It showed good characteristics in handling and capabilities to be developed as commercial products for golf courses. 2.Sludge from beer company needs proper treatment to improve physical properties for futher degradiation. It is because aggregation of the sludge particles prevented microbial activities and changing to soluble form. 3.Green carbon can be used as carbon source for organic fertilizer production using brewery sludge, but it should not contain wood extract which inhibit seed germination and seedling growth.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.407-414
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• 2007

In order to evaluate the physicochemical properties of sludge compost and to identify the effects water-extracts from sludge compost in 2, 6, 8, 12 weeks of decomposing process on seed germination and root elongation in cabbage, lettuce, soybean and barley plants was investigated. The content of total nitrogen in sludge compost increased slightly in 6 weeks decomposing process, and then decreased gradually. Organic matter content decreased continuously overall decomposing process. As decomposition was processing, pH of sludge compost decreased slightly, and EC increase within 6 weeks decomposing process, and then decreased. The content of nitrogen in water-extracts from sludge compost increased within 8 weeks decomposing process and decreased in 12 weeks decomposing process. The content of ammonium nitrogen was similar with that of total nitrogen, and the ratio of ammonium and nitrate increased within 8 weeks, and then decreased. Cation content and EC decreased the late of decomposing process and pH didn't change. The water-extracts from sludge compost during decomposing process inhibited seed germination and root elongation in cabbage (Brassica campestris), lettuce (Lactuca sativa), barley (Hordeum vulgare) and soybean (Glycine max). The inhibition of root elongation in cabbage was greater than that of relative seed germination, whereas relative seed germination in lettuce was more inhibit than root elongation. Relative seed germination and root elongation in soybean were inhibited slightly, but those of in barley was inhibited strongly. In this study, we would identify the effects of water-extracts from sludge compost on seed germination and root elongation was different to the species of seed. The inhibition of seed germination and root elongation treated with the water-extracts which extracted from sludge compost in the early stage of decomposing process was greater than that of in the late stage of decomposing process.

• Environmental Engineering Research
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• v.11 no.4
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• pp.173-180
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• 2006

Autotrophic nitrogen removal and its microbial community from a laboratory scale upflow anaerobic sludge bed reactor were characterized with dynamic behavior of nitrogen removal and sequencing result of molecular technique (DNA extraction, PCR and amplification of 16S rDNA), respectively. In the experiment treating inorganic wastewater, the anaerobic granular sludge from a full-scale UASB reactor treating industrial wastewater was inoculated as seed biomass. The operating results revealed that an addition of hydroxylamine would result in lithoautotrophic ammonium oxidation to nitrite/nitrate, and also hydrazine would play an important role for the success of sustainable nitrogen removal process. Total N and ammonium removal of 48% and 92% was observed, corresponding to nitrogen conversion of 0.023 g N/L-d. The reddish brown-colored granular sludge with a diameter of $1{\sim}2\;mm$ was observed at the lower part of sludge bed. The microbial characterization suggests that an anoxic ammonium oxidizer and an anoxic denitrifying autotrophic nitrifier contribute mainly to the nitrogen removal in the reactor. The results revealed the feasibility on development of high performance lithoautotrophic nitrogen removal process with its microbial granulation.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.1
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• pp.35-45
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• 2023

In this study, the sludge formation in the wastewater drain from the advanced packaging process mechanisms are revealed as well as the key factors, materials, and sludge prevention methods using surfactant. Compared with that of conventional packaging process, advanced packaging process employ similar process to the semiconductor fabrication process, and thus many processes may generate wastewater. In specific, a large amount of wastewater may generate during the carrier wafer bonding, photo, development, and carrier wafer debonding processes. In order to identify the key factors for the formation of sludge during the advanced packaging process, six types of chemicals including bonding glue, HMDS, photoresist (PR), PR developer, debonding cleaner, and water are utilized and mixing evaluation is assessed. As a result, it is confirmed that the black solid sludge is formed, which is originated by the sludge seed formation by hydrolysis/dehydration reaction of HMDS and sludge growth via hydrophobic-hydrophobic binding with sludge seed and PR. For the sludge prevention investigation, three surfactants of CTAB, PEG, and shampoo are mixed with the key materials of sludge, and it is confirmed that the sludge formations are successfully suppressed. The underlying mechanism behind the sludge formation is that the carbon tails of the surfactant bind to PR with hydrophobic-hydrophobic interaction and inhibit the reaction with HMDS-based slurry seeds to prevent the sludge formation. In this regard, it is expected that various problems like clogging in drains and pipes during the advanced packaging process may effectively solve by the injection of surfactants into the drains.

• Journal of Forest and Environmental Science
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• v.36 no.4
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• pp.281-289
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• 2020

The study was conducted to observe the effects of compost of faecal sludge (FSC) and food waste (FWC) on seed germination and initial growth performance of Acacia auriculiformis and Swietenia mahagoni seedlings at the nursery of Chittagong University, Bangladesh. Before sowing the seeds, different combinations of FSC and FWC were incorporated with nutrient-deficient natural forest soils. Seed germination and growth parameters of seedlings were recorded after two, three and four month of seed sowing. We observed that seed germination (%) and seedlings growth parameters varied significantly (p<0.05) in the soil added with FSC and FWC in comparison to control. The highest germination was observed 88.89% for A. auriculiformis in combination of soil and FSC at 3:1 and 92.59% for S. mahagoni where soil combined with FWC at 4:1. The seedling biomass and other growth parameters of A. auriculiformis and S. mahagoni was also observed with combinations of soil with FSC 3:1 and soil with FWC 4:1. Therefore, the study revealed that the compost of both FS and FW can be a good soil conditioner for the initial growth of forest seedlings and the proven combinations can help to grow quality seedlings in the nursery.

• Environmental Engineering Research
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• v.11 no.3
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• pp.127-133
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• 2006

Aerobic floc-like sludge was formed in a batch reactor and the effect of cations on the formation of aerobic floc-like sludge was studied. In order to enhance the formation (rate) of aerobic floc-like sludge, cations such as $K^+$, $Na^+$, $Ca^{2+}$, and $Mg^{2+}$ were added to the seed sludge. It was found that $Ca^{2+}$ had positive effect on the formation of floc-like sludge, as measured by sludge volume index (SVI) for settle ability. The formation of floc-like sludge was confirmed by the microscopic observation after DAPI staining. The scattered forms of sludge samples at the initial stage became aggregated to form floes after $Ca^{2+}$ addition. To ensure the functions of sludge floes in a treatment plant, the gradient of ionic species around the surfaces of floc-like sludge was monitored by ion selective microelectrodes for ${NH_4}^+,\;{NO_3}^-$, and pH. The effective concentration of $Ca^{2+}$ ion to form floc-like sludge was determined to be 750 mg/L (0.15 mg $Ca^{2+}/mg$ MLSS). Under the effective $Ca^{2+}$ condition, the SVI value was the lowest and large distribution of nitrifying bacteria at the outer surface was observed in the aerobic floc-like sludge. From the results, it was found that the calcium ion functioned as an agent for the formation of aerobic floc-like sludge, resulting in the enhanced nitrification.

• Journal of Hydrogen and New Energy
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• v.15 no.3
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• pp.187-193
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• 2004

In this study, Anaerobic sewage sludge in a batch reactor operation at $35^\circ{C}$ was used as the seed to investigate the effect of pretreatments of waste activated sludge and to evaluate its hydrogen production potential by anaerobic fermentation. Various pretreatments including physical, chemical and biological means were conducted to utilize for substrate. As a result, SCODcr of alkali and mechanical treatment was 15 and 12 times enhanced, compared with a supernatant of activated sludge. And SCODcr was 2 time increase after re-treatment with biological hydrolysis. Those were shown that sequential hybridized treatment of sludge by chemical & biological methods to conform hydrogen production potential in bath experiments. When buffer solution was added to the activated sludge, hydrogen production potential increased as compare with no addition. Combination of alkali and mechanical treatment was higher in hydrogen production potential than other treatments.