Combination of nitrate and sodium nitroprusside dosing for sulfide control with low carbon source loss in sewer biofilm reactors

2021 ◽  
pp. 127527
Author(s):  
Guijiao Zhang ◽  
Zhi Yang ◽  
Yongchao Zhou ◽  
David Z. Zhu ◽  
Yiping Zhang ◽  
...  
2012 ◽  
Vol 65 (9) ◽  
pp. 1676-1683 ◽  
Author(s):  
G. M. Tardy ◽  
V. Bakos ◽  
A. Jobbágy

A survey has been carried out involving 55 Hungarian wastewater treatment plants in order to evaluate the wastewater quality, the applied technologies and the resultant problems. Characteristically the treatment temperature is very wide-ranging from less than 10 °C to higher than 26 °C. Influent quality proved to be very variable regarding both the organic matter (typical COD concentration range 600–1,200 mg l−1) and the nitrogen content (typical NH4-N concentration range 40–80 mg l−1). As a consequence, significant differences have been found in the carbon availability for denitrification from site to site. Forty two percent of the influents proved to lack an appropriate carbon source. As a consequence of carbon deficiency as well as technologies designed and/or operated with non-efficient denitrification, rising sludge in the secondary clarifiers typically occurs especially in summer. In case studies, application of intermittent aeration, low DO reactors, biofilters and anammox processes have been evaluated, as different biological nitrogen removal technologies. With low carbon source availability, favoring denitrification over enhanced biological phosphorus removal has led to an improved nitrogen removal.


2014 ◽  
Vol 49 (3) ◽  
pp. 234-244
Author(s):  
Fang He ◽  
Fusheng Li ◽  
Haihong Zhou ◽  
Lingling Niu ◽  
Liguo Wang

In this research, biocompounds designed out of two polymers having different degradability was investigated for use as the sole carbon source and biofilm carrier to remove perchlorate in particle-fixed biofilm reactors. Both laboratory batch and column experiments were conducted with perchlorate contaminated groundwater. Batch experiments demonstrated clearly that ClO4– was removed from the aqueous phase readily and the degradation rate constants (k) changed in the range of 0.23–0.37 mg/L h as ClO4– concentration increased from 2 to 8 mg/L. Simultaneous perchlorate and nitrate degradation occurred in the polymer bioreactor. Effluent concentrations of perchlorate varied positively with temperature and fitted the Arrhenius equation expression as k=k20•100.0316(t–20) over the range of 13–30 °C. No perchlorate was detected in the effluent of polymer columns after 20 days’ startup. Complete perchlorate removal was observed at a hydraulic loading rate doubled to 1.8 mL/min. Images prove the concept of the pore and filament structure within the biocompounds, which provide both a heterotrophic biofilm and carbon source. Denaturing gradient gel electrophoresis analysis and partial sequencing of 16S rRNA genes indicated that formerly reported perchlorate-reducing bacteria were present in the polymer particle-fixed biofilm reactors.


2020 ◽  
Vol 37 ◽  
pp. 101414 ◽  
Author(s):  
Yifan Chen ◽  
Zhiyu Shao ◽  
Zheng Kong ◽  
Li Gu ◽  
Junhua Fang ◽  
...  

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2113-2116 ◽  
Author(s):  
C. J. Lu ◽  
S. J. Chen

The effects of the presence of a secondary carbon source on the biodegradation of chlorinated phenols were studied with column biofilm reactors. The biodegradability of chlorinated phenols was studied with a series of batch reactors. The biodegradability of chlorinated phenols was to follow the order of phenol > 2,4-dichlorophenol > 4-chIorophenol > 2,4,6-trichlorophenol > 2-chlorophenol > 3-chloro-phenol. The presence of a relatively more biodegradable but higher chlorinated phenol, such as 2,4,6-trichlorophenol, enhanced the biodégradation of a less chlorinated butrecalcitrantphenol, such as 2-chlorophenol. The addition of phenol, an easily biodegradable compound, generally decreased the biodegradation of chlorinated phenols.


Author(s):  
Qian Zhang ◽  
Xue Chen ◽  
Heng Wu ◽  
Wandong Luo ◽  
Xiangyang Liu ◽  
...  

In recent years, there is a trend of low C/N ratio in municipal domestic wastewater, which results in serious problems for nitrogen removal from wastewater. The addition of an external soluble carbon source has been the usual procedure to achieve denitrification. However, the disadvantage of this treatment process is the need of a closed, rather sophisticated and costly process control as well as the risk of overdosing. Solid-phase denitrification using biodegradable polymers as biofilm carrier and carbon source was considered as an attractive alternative for biological denitrification. The start-up time of the novel process using PCL (polycaprolactone) as biofilm carrier and carbon source was comparable with that of conventional process using ceramsite as biofilm carrier and acetate as carbon source. Further, the solid-phase denitrification process showed higher nitrogen removal efficiency under shorter hydraulic retention time (HRT) and low carbon to nitrogen (C/N) ratio since the biofilm was firmly attached to the clear pores on the surface of PCL carriers and in this process bacteria that could degrade PCL carriers to obtain electron donor for denitrification was found. In addition, solid-phase denitrification process had a stronger resistance of shock loading than that in conventional process. This study revealed, for the first time, that the physical properties of the biodegradable polymer played a vital role in denitrification, and the different microbial compositions of the two processes was the main reason for the different denitrification performances under low C/N ratio.


Author(s):  
Irina Safitri Zen ◽  
Masilah Bandi ◽  
Kasturi Devi Karniah ◽  
Iklil Nabihah Binti Abu Bakar ◽  
Rozana Zakaria

The establishment of low carbon assessment initiatives is a crucial task especially at the city level. The determination of which source of carbon contributed more require robust data set and strategic approach. Hence, by using the campus as a small city approach, the establishment of carbon assessment and its’ reduction initiatives was required to keep track of the hotspot of the carbon source. The substantial amount of carbon source from campus operations such as energy consumption in the building, waste generation, and water consumption were identified. Moreover, as institutions of higher education, the execution of low carbon campus was initiated structurally involves the triangulation of research activities, teaching & learning and as well as campus operations or known as campus living lab approach. The application of low carbon cities framework, LCCF and assessment system enables to strategize the low carbon campus initiatives through the use of carbon footprint concept and the LCCF carbon track.


Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1242 ◽  
Author(s):  
Liu ◽  
Huang ◽  
Xiong ◽  
Wang ◽  
Chen ◽  
...  

Carbon source precursors for high-grade, clean, and low-carbon refractories were obtained by in situ exfoliation of flake graphite (FG) and phenol–formaldehyde resin (PF) composites with three-roll milling (TRM) for the fabrication of graphite nanoplatelets. In addition, by using Ni(NO3)2·6H2O as a catalyst in the pyrolysis process, multidimensional carbon nanostructures were obtained with coexisting graphite nanoplatelets (GNPs), glassy carbon (GC), and carbon nanotubes (CNTs). The resulting GNPs (exfoliated 16 times) had sizes of 10–30 μm, thicknesses of 30–50 nm, and could be uniformly dispersed in GC from the PF pyrolysis. Moreover, Ni(NO3)2·6H2O played a key role in the formation and growth of CNTs from a catalytic pyrolysis of partial PF with the V–S/tip growth mechanisms. The resulting multidimensional carbon nanostructures with GNPs/GC/CNTs are attributed to the shear force of the TRM process, pyrolysis, and catalytic action of nitrates. This method reduced the production costs of carbon source precursors for low-carbon refractories, and the precursors exhibited excellent performances when fabricated on large scales.


1996 ◽  
Vol 33 (12) ◽  
pp. 99-108 ◽  
Author(s):  
John Barlindhaug ◽  
Hallvard Ødegaard

Thermal hydrolysate is the liquid fraction (supernatant) of thermally treated wastewater sludge. The objective of the present study was to investigate the quality of thermal hydrolysate as a carbon source for denitrification. Steady state denitrification experiments in moving bed biofilm reactors were carried out. It was demonstrated that 2/3 of the COD in the thermal hydrolysate was utilised as a carbon source in the post denitrification step, with a retention time of 52 minutes. This degree of utilisation is about the same as reported for biological hydrolysate, which generally has been considered to be of better quality as a carbon source than thermal hydrolysate. The yield of soluble COD in the thermal hydrolysis process (180°C in 30 minutes) was found to be 28%. Typical COD-yields for biological hydrolysis are around 11%.


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