scholarly journals Assessment of Multiple Anaerobic Co-Digestions and Related Microbial Community of Molasses with Rice-Alcohol Wastewater

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4866 ◽  
Author(s):  
Sohail Khan ◽  
Fuzhi Lu ◽  
Qiong Jiang ◽  
Chengjian Jiang ◽  
Muhammad Kashif ◽  
...  

Molasses is a highly dense and refined byproduct produced in the sugarcane industry, and it contains high amounts of degradable compounds. Through bioconversion, these compounds can be transformed into renewable products. However, the involved biological process is negatively influenced by the high chemical oxygen demand (COD) of molasses and ion concentration. The co-digestion of molasses with rice-alcohol wastewater (RAW) was compared with its mono-digestion at an increasing organic loading rate (OLR). Both processes were assessed by detecting the COD removal rate, the methane contents of biogas, and the structure and composition of microbial communities at different stages. Results showed that the co-digestion is stable up to a maximum OLR of 16 g COD L−1 d−1, whereas after the acclimatization phase, the mono-digestion process was disturbed two times, which occurred at a maximum OLR of 9 and 10 g COD L−1 d−1. The volatile fatty acids (VFAs) observed were 2059.66 mg/L and 1896.9 mg/L, which in mono-digestion causes the inhibition at maximum OLRs. In the co-digestion process, the concomitant COD removal rates and methane content recorded was 90.72 ± 0.63% 64.47% ± 0.59% correspondingly. While in the mono-digestion process, high COD removal rate and methane contents observed were 89.29 ± 0.094% and 61.37 ± 1.06% respectively. From the analysis of microbial communities, it has been observed that both the bacterial and archaeal communities respond differently at unlike stages. However, in both processes, Propionibacteriaceae was the most abundant family in the bacterial communities, whereas Methanosaetaceae was abundant in the archaeal communities. From the current study, it has been concluded that that rice-alcohol wastewater could be a good co-substrate for the anaerobic digestion of molasses in terms of COD removal rate and methane contents production, that could integrate molasses into progressive biogas production with high OLR.

2020 ◽  
Author(s):  
Sohail Khan ◽  
Fuzhi Lu ◽  
Qiong Jiang ◽  
Chengjian Jiang ◽  
Muhammad Kashif ◽  
...  

Abstract Background Molasses is a highly dense and refined byproduct produced in the sugarcane industry, and it contains high amounts of degradable compounds. These compounds can potentially be converted into renewable products biologically. However, the involved biological process is negatively influenced by the high chemical oxygen demand (COD) of molasses and its high ion concentration, although this problem is commonly addressed by dilutions. Results The co-digestion of molasses with rice alcohol waste water (RAW) was compared with its mono-digestion at an increasing organic loading rate (OLR). Both processes were assessed by detecting the COD removal rate, the methane contents of biogas, and the structure and composition of microbial communities at different stages. Results showed that the co-digestion is stable up to a maximum OLR of 16 g COD L− 1d− 1. By contrast, after the acclimatization phase, the mono-digestion process was upset twice, which occurred at a maximum OLR of 9 and 10 g COD L− 1d− 1. The co-digestion procgess demonstrated consistency in terms of COD removal rates (86.36% ± 0.99–90.72% ± 0.63%) and methane contents (58.10% ± 1.12–64.47% ± 0.59%) compared with the mono-digestion process. Microbial community analysis showed that the relative abundance of bacterial and archaeal communities differs between the processes at different stages. However, in both processes, Propionibacteriaceae was the most abundant family in the bacterial communities, whereas Methanosaetaceae was abundant in the archaeal communities. Conclusion Rice alcohol wastewater could be a good co-substrate for anaerobic digestion of molasses. Integrate molasses into progressive biogas production at high OLR.


1986 ◽  
Vol 18 (7-8) ◽  
pp. 249-256 ◽  
Author(s):  
T. Noike ◽  
J. Matsumoto

The upgrading of night soil anaerobic digestion processes was studied by field investigation of the performance of anaerobic digesters in existing night soil treatment plants and by serai-continuous experiments with bench-scale digesters. Both the average monthly amount of collected night soil fed to a digester and the concentration of volatile solids in night soil increased in winter. A good correlation was found to exist between gas production and digestion temperature. The COD removal rate in the first digester was markedly higher than that in the second digester. The stirring period in the first digester in one plant differs from that in the other plant. Stirring the first digester for too long a period reduces the rate of COD removal by the second digester in the two-stage anaerobic digestion process. The first digester should be stirred for more than one hour per day in order to promote gas production. Gas production and CODCr removal rate in the second digester were hardly affected by reductions in retention time ranging from 15 days to 5 days. As night soil contains a large amount of cellulose and other refractory organics, some kind of pretreatment of the night soil fed to the digester may be necessary for the promotion of acidogenesis in the two-phase anaerobic digestion process.


2021 ◽  
Vol 13 (9) ◽  
pp. 4971
Author(s):  
Sohail Khan ◽  
Fuzhi Lu ◽  
Muhammad Kashif ◽  
Peihong Shen

Molasses is a highly thick by-product produced after sugarcane crystallization constitutes large amounts of biodegradable organics. These organic compounds can be converted to renewable products through anaerobic digestion. Nevertheless, its anaerobic digestion is limited due to its high chemical oxygen demand (COD) and ion concentration. The effects of nickel (Ni2+) on the stability of anaerobic digestion of molasses were established by studying the degradation of organic matter (COD removal rate), biogas yield, methane content in the biogas, pH, and alkalinity. The results showed that there were no significant effects on the stability of pH and alkalinity. Increased COD removal rate and higher methane content was observed by 2–3% in the digesters receiving 2 and 4 mg/L of Ni2+ in the first phase of the experiment. Ni2+ supplemented to reactors at concentration 2 mg/L enhanced biogas yield. Overall, it is suggested that the addition of Ni2+ has some effects on the enhancement of biogas yield and methane contents but has no obvious effects on the long-lasting stability of the molasses digestion.


2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Quang-Minh Nguyen ◽  
Duy-Cam Bui ◽  
Thao Phuong ◽  
Van-Huong Doan ◽  
Thi-Nham Nguyen ◽  
...  

The effect of copper, zinc, chromium, and lead on the anaerobic co-digestion of waste activated sludge and septic tank sludge in Hanoi was studied in the fermentation tests by investigating the substrate degradation, biogas production, and process stability at the mesophilic fermentation. The tested heavy metals were in a range of concentrations between 19 and 80 ppm. After the anaerobic tests, the TS, VS, and COD removal efficiency was 4.12%, 9.01%, and 23.78% for the Cu(II) added sample. Similarly, the efficiencies of the Zn(II) sample were 1.71%, 13.87%, and 16.1% and Cr(VI) efficiencies were 15.28%, 6.6%, and 18.65%, while the TS, VS, and COD removal efficiency of the Pb(II) added sample was recorded at 16.1%, 17.66%, and 16.03% at the concentration of 80 ppm, respectively. Therefore, the biogas yield also decreased by 36.33%, 31.64%, 31.64%, and 30.60% for Cu(II), Zn(II), Cr(VI), and Pb(II) at the concentration of 80 ppm, compared to the raw sample, respectively. These results indicated that Cu(II) had more inhibiting effect on the anaerobic digestion of the sludge mixture than Zn(II), Cr(VI), and Pb(II). The relative toxicity of these heavy metals to the co-digestion process was as follows: Cu (the most toxic) > Zn > Cr > Pb (the least toxic). The anaerobic co-digestion process was inhibited at high heavy metal concentration, which resulted in decreased removal of organic substances and produced biogas.


2012 ◽  
Vol 518-523 ◽  
pp. 2745-2748
Author(s):  
Ling Yan Ren ◽  
Gang Xu

The paper adopted Coagulation-Fenton Oxidation Method on treating the wastewater of 6-nitro-1,2 diazonium oxygroup naphthalene-4-sulfoacid production process (i.e. 6-nitry wastewater), introduced the treatment effect of the combined technology used on 6-nitry wastewater, and studied the factors influencing the treatment effect, to determine the reasonable parameters of the technology on treating 6-nitry wastewater. The results showed that Using polyaluminium chloride (mass fraction 2%) as flocculant for treating 6-nitry wastewater, the COD removal rate reached up to 48.7%; Making Fenton reagent oxidation treatment on coagulation yielding water, under the best conditions for solution acidity controlled at pH3 or so, in the 100 mL wastewater, 30% hydrogen peroxide was 5.0 mL, 0.5 mol/L ferrous sulfate solution was 4.0 mL, reaction time was 60 min, the COD removal rate could reach 98% or more.


2013 ◽  
Vol 726-731 ◽  
pp. 2316-2319
Author(s):  
Hai Xia Duan

TNT-RDX wastewater is hard to biodegrade and highly toxic. The self-made reactor was used to degrade the wastewater, spray and the conditions of droplet diameter, number of nozzle, spray height were clearly observed. The results show that the average COD removal rate of TNT-RDX wastewater was 69.6%.The spray conditions can improve the dispersion of the wastewater and increase the use of the residual ozone in gas phase. Keywords: Spray; TNT-RDX wastewater; ozone; UV; GAC


2012 ◽  
Vol 9 ◽  
pp. 57-62
Author(s):  
Fiza Sarwar ◽  
Wajeeha Malik ◽  
Muhammad Salman Ahmed ◽  
Harja Shahid

Abstract: This study was designed using actual effluent from the sugary mills in an Up-flow Anaerobic Sludge Blanket (UASB) Reactor to evaluate treatability performance. The reactor was started-up in step-wise loading rates beginning from 0.05kg carbon oxygen demand (COD)/m3-day to 3.50kg-COD/m3-day. The hydraulic retention time (HRT) was slowly decreased from 96 hrs to eight hrs. It was observed that the removal efficiency of COD of more than 73% can be easily achieved at an HRT of more than 16 hours corresponding to an average organic loading rate (OLR) of 3.0kg-COD/m3-day, at neutral pH and constant temperature of 29°C. The average VFAs (volatile fatty acids) and biogas production was observed as 560mg/L and 1.6L/g-CODrem-d, respectively. The average methane composition was estimated as 62%. The results of this study suggest that the treatment of sugar mills effluent with the anaerobic technology seems to be more reliable, effective and economical.DOI: http://dx.doi.org/10.3126/hn.v9i0.7075 Hydro Nepal Vol.9 July 2011 57-62


2019 ◽  
Vol 38 (3) ◽  
pp. 243
Author(s):  
Happy Mulyani ◽  
Gregorius Prima Indra Budianto ◽  
Margono Margono ◽  
Mujtahid Kaavessina

Industrial wastewater treatment using Sequencing Batch Reactor (SBR) can improve effluent quality at lower cost than that obtained by other biological treatment methods. Further optimization is still required to enhance effluent quality until it meets standard quality and to reduce the operating cost of treatment of high strength organic wastewater. The purpose of this research was to determine the effect of pretreatment (pH adjustment and prechlorination) and aeration time on effluent quality and COD removal rate in tapioca wastewater treatment using SBR. Pretreatment was done by (1) adjustment of tapioca wastewater pH to control (4.92), 7, and 8, and (2) tapioca wastewater prechlorination at pH 8 during hour using calcium hypochlorite in variation dosages 0, 2, 4, 6 mg/L Cl2, SBR operation was conducted according to following steps: (1) Filling of pre-treated wastewater into a bioreactor during 1 hour, and (2) aeration of the mixture of tapioca wastewater and activated sludge during 8 hours. Effluent sample was collected at every 2-hours aeration for COD analysis. COD removal rate mathematical formula was got by first deriving the best fit function between aeration time and COD. Optimum aeration time resulting in no COD removal rate. The value of COD effluent and its removal rate in optimum aeration time was used to determine the recommended of operation condition of pretreatment. Research result shows that chosen pH operation condition is pH 8. Prechorination can make effluent quality which meets standard quality and highest COD removal rate. The chosen Cl2 dosage is 6 mg/L.


2014 ◽  
Vol 1044-1045 ◽  
pp. 215-218
Author(s):  
Xian Huan Qiu ◽  
Hai Yu ◽  
Peng Fei Deng

In the presence of acetic acid, the effects of pH, processing time, addition of Fe2+ and H2O2 on dye wastewater treatment were studied. Experimental results showed that in the presence of acetic acid, when the pH value was 4, the processing time was 30.0min, addition of ferrous sulfate was 4.8g/L, and addition of hydrogen peroxide was 56mL/L, the treatment effect was the best, COD removal rate reached 51.0%. Further studied of the effect of the presence of acetic acid on Fenton’s oxidation of dye wastewater, the results showed that without of acetic acid, the COD removal rate was higher than that with acetic acid. And the effect of Fenton's reagent on oxidation of dye substances was interfered by the presence of acetic acid.


2010 ◽  
Vol 62 (6) ◽  
pp. 1379-1385 ◽  
Author(s):  
Lin Song ◽  
Jiang Wenju ◽  
Tang Qiong ◽  
Li Yaozhong

This study investigated the effects of 2,4-dichlorophenol on reduction of activated sludge in membrane bioreactors. Significant inhibition on sludge growth and slight reduction in COD removal were observed at higher 2,4-dichlorophenol dosages. The deviation between relative specific COD removal rate (q/q0) and relative specific growth rate (μ/μ0) suggested that a minimum 2,4-dichlorophenol concentration was required for uncoupling of anabolism and catabolism. With the increase of the dosage of 2,4-dichlorophenol, stepwise improvement of biomass bioactivity and the reduction in activated sludge production were achieved simultaneously. Compared with the control bioreactor, the peak distribution of floc size in the 2,4-dichlorophenol added bioreactor shifted to a range of smaller floc size. Besides, addition of 2,4-dichlorophenol caused little variation of microorganism community structure and SVI value of the sludge. After 24-hour operation, the residue 2,4-dichlorophenol concentration in the bioreactors was reduced to a negligible level.


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