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Due to the disadvantages of physiochemical methods for sulfidic spent caustic treatment, attentions are drawn to the environmental-friendly biotreatments including sulfur-oxidizing haloalkaliphiles. Thioalkalivibrio versutus DSM 13738 was grown at alkaline (pH10) autotrophic medium with sodium carbonate/bicarbonate as the sole source of carbon and amended with sodium thiosulfate as the electron and energy source. The effect of various parameters including temperature (25-40 °C), pH (8-11), NaCl concentration (0.5-5 % w/v) and sodium thiosulfate concentrations (100-750 mM) was evaluated on bacterial growth and thiosulfate removal. This strain could eliminate sodium thiosulfate at very high concentrations up to 750 mM. The results showed that the highest specific growth rate was pH 9.5 and thiosulfate removal of Thioalkalivibrio versutus occurred at pH 10.5. The optimum salt concentration for thiosulfate removal was 2.5 % w/v and 5 % NaCl and specific growth rate elevated 2.5% w/v. It was also specified that this strain thrives occurred in 37 ºC and at 35 and 37 ºC higher removal of thiosulfate. Following chemical oxidation of sulfide to thiosulfate, application of Thioalkalivibrio versutus could be promising for spent caustic treatment. Since thiosulfate is utilized as an energy source, highest removal efficiency occurred at marginally different conditions compared to optimal growth.
With the recent use of bacterial technology for the restoration of a polluted urban stream in China, this paper will show the general feasibility of such biological treatment from the perspective of numerical modelling. Based on the results, a low concentration of BOD₅ can be achieved in shorter distance for higher bacterial concentration applied. Generally greater flow of domestic wastewater will be proportionally balanced by higher bacterial growth. Under limited DO concentration, higher bacterial concentration would also create a breaking point on the declining distribution of BOD₅. The combination of oxygenation and artificial mixing of bacteria would result in lower concentrations of BOD₅ at the downstream.
Our paper analyzes the quality of combined wastewater in the aspect of its biological treatment. Fractions of chemical oxygen demand (COD) and total Kjeldahl nitrogen (TKN) in the inflow to the Group Wastewater Treatment Plant in Łódź were determined. The research revealed a distinct increase of inert fractions during wet weather caused by an increasing portion of contaminants bound with suspended solids.
The functionalized mesoporous’ potential ability of binding heavy metals using different templates, namely cetyltrimethylammonium (CTAB) (adsorbent A) and triblock copolymer (Pluronic P123, EO20PO70EO2O, Mav = 5800) (adsorbent B), was evaluated. The synthesized materials were characterized by powder X-ray diffraction (XRD), nitrogen gas sorption, FT-IR and solid-state ¹³C and ²⁹Si NMR spectroscopy and thermogravimetry (TGA) measurements. In the adsorption experiment, the effects of several variables (stirring time, pH and presence of other metals in the medium) were studied. On the basis of these results, it was observed that the adsorption capacities were higher for adsorbent B than adsorbent A. The results also confirmed that the ureido group (CO-NH₂) has a good affect of binding metal ion.
Influence of the wastewater from chosen food processing industries located in Szczecin on a quality of receiver’s water was presented. The theoretical part of the paper comprises general fundamentals of the biological treatment of the wastewater, the sources of the wastewater and their impact onto a sewerage system and the receiver at meat processing and dairy industries were also presented in this part of the paper. Szczecin Dairy and Szczecin Poultry Processing Company are both equipped with biological wastewater treatment plants. The treated wastewater is discharged to the receivers that are directly linked to River Odra, thus has an impact on the quality of River Odra water. Basing on a performed research on parameters of untreated and treated wastewater, the treatment performance of the wastewater treatment plants was described as well as an attempt to estimation of an impact of the wastewater onto the receiver was made.
This work evaluates municipal solid waste (MSW) management options with respect to energy and environmental indicators. Two alternative scenarios have been analyzed: incineration of waste after mechanical biological treatment (MBT) and mass burning. The city of Kaunas, Lithuania, served as an object of the research. The calculations revealed that in the case of incineration of MBT-processed waste, only 2.4-2.8% of municipal heat energy requirements may be satisfied, while mass burning may provide up to 20% of integrated municipal heat energy requirements. The incineration of MBT-processed waste would result in 36% higher exhaust gas volume, 39% higher HCl emissions and 57% higher SO2 emissions per ton of waste, compared to mass-burned waste. The presented approach may be applied to countries experiencing transitions of MSW management systems.
This experiment examined the efficiency of biological removal of air contaminants performed with a prototype “open” biofilter. The biofilter bed composed the following components by weight: 35% fibrous peat, 35% sallow peat, 10% barley straw, composts from sewage plant and horse manure -10% each. With Waters` liquid chromatograph use there was determined a content of ammonia, nitrates, nitrites, sulphates, chloride phosphates, iodides, bromides and fluorides in the air. The examinations on the physico-chemical properties of medium and air pollution were run over 180 days, collecting the samples on the 5th, 35th, 65th, 95th and 180thbiofiltration days. After 35 days there was recorded stabilization of temperature, moisture, reaction, dynamic growth of total bacteria count and coli titre in the medium. Ammonia biofiltration efficiency ranged from 36 to 89%, while for nitrates, nitrites and phosphates it was even higher than 66-100%.
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