This work is focused on the use of nutrients from dairy wastewaters as fertilizers, studying the optimum operational conditions for the bio-mineralization of the nitrogen organic matter. Wastewaters ...from 1500 to 2500 mg COD/l and at alkaline pH of between 8.5–12 were studied, in an aerobic biological treatment at a bench scale. The temperature was maintained at 30°C. In some experiments, the COD was reduced at the same time as nitrification. An increase of the organic load produced a delay in the appearance of the ammonium, though the concentrations reached were greater than with lower loads. The phosphate profiles was parallel to that of ammonium. However, the ammonium becomes exhausted as a consequence of the release of ammonium, as ammonia, to the atmosphere and of consumption by the microorganisms, whose metabolic requirements for ammonium are greater that those for phosphate. The experiments with an initial COD of 1500 mg/l and pH of 10.5 completed nitrification within the 30-day test period. The maximum concentrations of ammonium were reached when the initial pH was 8.5. On the other hand, the highest rates of protein hydrolysis were recorded at initial pH of 10.5 and 11.0 units. Part of the nitrogen present in milk was lost as ammonia when the initial pH was 11.5 and 12.0.
The algae removal efficiency of a pilot plant--based on a fluidized-bed biofilm reactor system for treating--was investigated. This system does not require back-washing because the fluidized-bed ...suffers no clogging. Moreover, the system uses dissolved oxygen in the influent water for aerobic biological treatment without the need for additional aeration equipment. This, it is an easy-maintenance, low-energy system for purifying eutrophic lake water. The system was operated continuously at a flow rate of 1500 m3/d for nine months at Tsuchiura Port in Lake Kasumigaura. And concentrations of chlorophyll-a and dissolved oxygen in both the influent and effluent water were continuously monitored. In summer (August to September) when water bloom occurred, the average efficiency of chlorophyll-a removal was 64% at an average influent chlorophyll-a concentration of 137.8 micrograms/L. Over the entire experimental period of nine months, the average daily amount of removed chlorophyll-a was 40.3 g/d at an average influent chlorophyll-a concentration of 89.5 micrograms/L. By analyzing the relationship between the amount of removed chlorophyll-a and the consumption of dissolved oxygen, it was estimated that almost all of the algae trapped in the reactor was biologically degraded.
This paper describes a pilot plant study on algae removal of a fluidized bed biofilm reactor system for lake water treatment. The system does not need backwashing because the fluidized bed suffers no ...clogging. Moreover, the system uses dissolved oxygen in influent water for aerobic biological treatment without aeration equipment. Thus, this system is a low energy and easy maintenance way to purify eutrophic lake water. The system was operated continuously at a flow rate of 1500 m3·d-1 for 9 months at Tsuchiura Port in Lake Kasumigaura. In this study, chlorophyll-a and dissolved oxygen in both influent and effluent water were monitored continuously. In summer (August to September) when water bloom occurred, the average removal efficiency of chlorophyll-a was 64% at the average influent chlorophyll-a concentration of 137.8 μg·l-1. During the total experimental period (9 months), the average daily amount of removed chlorophyll-a was 40.3g·d-1 at the average influent chlorophyll-a concentration of 89.5 μg·l-1. By analyzing the relationship between the removed chlorophyll-a and the consumption of dissolved oxygen, it was estimated that almost all of algae trapped in the reactor was degraded biologically.
Effect of Compost Turning Frequency on the Composting and Biofiltration Hong, J.Y. (Sunchon National University, Sunchon, Republic of Korea), E-mail: davis46@sunchon.ac.kr; Park, K.J. (Sunchon National University, Sunchon, Republic of Korea)
Journal of Livestock Housing and Environment,
(Aug 2006), Letnik:
12, Številka:
2
Journal Article
The effects of turning frequency of in-vessel composting on ammonia emissions during composting of separated solids from swine slurry/sawdust mixtures and performance of biofiltration using the ...chicken manure compost were investigated. Separated solids from swine manure amended with sawdust was composted in a 226L laboratory-scale in-vessel reactors under various turning frequency and continuous airflow (0.6L/min.kg.dm) for three weeks. Three laboratory-scale manure compost biofilters were built to treat effluent gas from the composting of separated solid from swine manure amened with sawdust process.
Biotreatment of wastewater from a dimethyl terephthalate (DMT) plant in repeated batch mode with 24-h cycles and feed chemical oxygen demand (COD) of 2000 mg/
l, led to a COD reduction of ...approximately 86% in 20 h. Incorporation of porous plastic biomass support particles (BSP) in the reactor however, resulted in similar COD reduction in only 6 h. The increased percentage COD reduction in BSP reactor was found to be related to the increase in biomass (from 2.8 to 10.5 g/
l) in the reactor. In the continuous mode, the optimum organic loading and hydraulic retention time (HRT) for more than 90% COD reduction were found to be approximately 14 kg COD/m
3/d and 12 h, respectively, with the BSP reactor. On the other hand, only 40–45% COD reduction was observed under the same conditions in the reactor not containing the support particles. Reduction in percentage COD reduction at high organic loading rates was due to the presence of formaldehyde in the wastewater feed. The control reactor, not containing BSP, was found to be sensitive to formaldehyde concentrations above 160 mg/
l, while the reactor with BSP was resistant up to a formaldehyde concentration of 410 mg/
l. The advantages of the BSP augmentation for the aerobic biotreatment of DMT wastewater are discussed.
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