Anaerobic biodegradation of soybean-process wastewater: operation strategy and sludge bed characteristics of a high-performance Spiral Symmetric Stream Anaerobic Bioreactor

2021 ◽  
pp. 117095
Author(s):  
Xiaoguang Chen ◽  
Weizhu Zhou ◽  
Gongsong Li ◽  
Qi Song ◽  
Muhammad Ismail ◽  
...  
2021 ◽  
Author(s):  
Hui Jin

With the increase in waste recycling, municipal solid waste (MSW) with high organic and moisture contents are found in various landfills worldwide. If this kind of waste were put into anaerobic condition directly, the pH values will decrease sharply, which will seriously affect the biodegradation of the wastes. This study is aimed to investigate the decomposition of the type of MSW in aerobic condition before the anaerobic biodegradation. In the study, the effects of air addition and biosolids addition on the biodegradation of MSW with high organic and moisture contents were examined. Moreover, the flushing technology was compared with the leachate recirculation technology. Six simulated bioreactor landfills were set up. After about 100 days' operation, it was observed that (1) the mass reduction rate in the aerobic-anaerobic bioreactor was approximately five times of that in the anaerobic bioreactor, the leachate quality was much better than that in the anaerobic bioreactor based on the final COD, BOD 5, TS, and NH 3 concentrations. (2) biosolids have strong buffering effects and the addition of biosolids accelerated the anaerobic biodegradation progress to a great extent. Therefore, it was concluded that initially degrading MSW under aerobic condition before anaerobic degradation with biosolids addition is the optimum strategy for the decomposition of MSW with high organic and moisture contents.


2021 ◽  
Author(s):  
Hui Jin

With the increase in waste recycling, municipal solid waste (MSW) with high organic and moisture contents are found in various landfills worldwide. If this kind of waste were put into anaerobic condition directly, the pH values will decrease sharply, which will seriously affect the biodegradation of the wastes. This study is aimed to investigate the decomposition of the type of MSW in aerobic condition before the anaerobic biodegradation. In the study, the effects of air addition and biosolids addition on the biodegradation of MSW with high organic and moisture contents were examined. Moreover, the flushing technology was compared with the leachate recirculation technology. Six simulated bioreactor landfills were set up. After about 100 days' operation, it was observed that (1) the mass reduction rate in the aerobic-anaerobic bioreactor was approximately five times of that in the anaerobic bioreactor, the leachate quality was much better than that in the anaerobic bioreactor based on the final COD, BOD 5, TS, and NH 3 concentrations. (2) biosolids have strong buffering effects and the addition of biosolids accelerated the anaerobic biodegradation progress to a great extent. Therefore, it was concluded that initially degrading MSW under aerobic condition before anaerobic degradation with biosolids addition is the optimum strategy for the decomposition of MSW with high organic and moisture contents.


Author(s):  
Fatai Alade Aderibigbe ◽  
◽  
Tunmise Latifat Adewoye ◽  
Sherif Ishola Mustapha ◽  
Ishaq Alhassan Mohammed ◽  
...  

Mixed solid oxides are known for their excellent catalytic property and applications in environmental remediation. This study presents a green-synthesis route for magnesium oxide–titanium oxide, a mixed oxide here demonstrated to possess high performance of phenol removal from hydrocarbon refinery process wastewater. Mixed oxide (MgO-TiO2) was prepared by using the whole extract from leaves of Piliostigma Thonningii as reducing agent. A structural attribute of the mixed oxide was investigated using X-ray Diffractometer, High-Resolution Scanning Electronic Microscopy and Energy Dispersive X-ray. Petroleum refinery raw wastewater having phenol concentration of 19.961 mg/L was treated using the green-synthesized mixed oxide. Adsorptive phenols removal up to 99.5% was achieved with a dosage of 0.04 g/100 mL at temperature of 35 °C, and contact time of 1.167 h. By this, the treated water meets the standard acceptable phenol concentration (0.1 mg/L) in wastewater of hydrocarbon refinery.


2017 ◽  
Vol 120 ◽  
pp. 17-24 ◽  
Author(s):  
Ruobin Dai ◽  
Xiaoguang Chen ◽  
Puyue Ma ◽  
Xiaoxiao Chu ◽  
Xinyi Xiang ◽  
...  

Author(s):  
A. V. Crewe ◽  
M. Isaacson ◽  
D. Johnson

A double focusing magnetic spectrometer has been constructed for use with a field emission electron gun scanning microscope in order to study the electron energy loss mechanism in thin specimens. It is of the uniform field sector type with curved pole pieces. The shape of the pole pieces is determined by requiring that all particles be focused to a point at the image slit (point 1). The resultant shape gives perfect focusing in the median plane (Fig. 1) and first order focusing in the vertical plane (Fig. 2).


Author(s):  
N. Yoshimura ◽  
K. Shirota ◽  
T. Etoh

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.


Author(s):  
John W. Coleman

In the design engineering of high performance electromagnetic lenses, the direct conversion of electron optical design data into drawings for reliable hardware is oftentimes difficult, especially in terms of how to mount parts to each other, how to tolerance dimensions, and how to specify finishes. An answer to this is in the use of magnetostatic analytics, corresponding to boundary conditions for the optical design. With such models, the magnetostatic force on a test pole along the axis may be examined, and in this way one may obtain priority listings for holding dimensions, relieving stresses, etc..The development of magnetostatic models most easily proceeds from the derivation of scalar potentials of separate geometric elements. These potentials can then be conbined at will because of the superposition characteristic of conservative force fields.


Author(s):  
J W Steeds ◽  
R Vincent

We review the analytical powers which will become more widely available as medium voltage (200-300kV) TEMs with facilities for CBED on a nanometre scale come onto the market. Of course, high performance cold field emission STEMs have now been in operation for about twenty years, but it is only in relatively few laboratories that special modification has permitted the performance of CBED experiments. Most notable amongst these pioneering projects is the work in Arizona by Cowley and Spence and, more recently, that in Cambridge by Rodenburg and McMullan.There are a large number of potential advantages of a high intensity, small diameter, focussed probe. We discuss first the advantages for probes larger than the projected unit cell of the crystal under investigation. In this situation we are able to perform CBED on local regions of good crystallinity. Zone axis patterns often contain information which is very sensitive to thickness changes as small as 5nm. In conventional CBED, with a lOnm source, it is very likely that the information will be degraded by thickness averaging within the illuminated area.


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