scholarly journals Assessment of multiple anaerobic co-digestions and related microbial community of molasses with rice alcohol wastewater

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.

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.


Author(s):  
Md. Nurul Islam Siddique ◽  
Zularisham A. Wahid

The effect of gradual increase in organic loading rate (0LR) and temperature on biomethanation from petrochemical wastewater treatment was investigated using CSTR. The digester performance measured at hydraulic retention time (HRT) of4 to 2d, and start up procedure of the reactor was monitoredfor 60 days via chemical oxygen demand (COD) removal, biogas and methane production. By enhancing the temperature from 30 to 55 “C Thermophilic condition was attained, and pH was adjusted at 7 i 0.5. Supreme COD removal competence was 98i0.5% (r = 0.84) at an 0LR of 7.5 g-COD/Ld and 4d HRT. Biogas and methane yield were logged to an extreme of 0.80 L/g-CODremoved d (r = 0.81), 0.60 L/g-CODremoved d (r = 0.83), and mean methane content of biogas was 65.49%. The full acclimatization was established at 55 C with high COD removal efficiency and biogas production. An 0LR of 7.5 g-COD/L d and HRT of 4 days were apposite forpetrochemical wastewater treatment.


BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 4254-4269
Author(s):  
Jinghong Zhou ◽  
Xiaona Shang ◽  
Zhiwei Wang ◽  
Cancan Zhu ◽  
Shuangfei Wang

Bagasse spraying wastewater (BSW) is a source of organic pollutants during bagasse processing. In this study, the feasibility of anaerobic treatment of BSW under different calcium concentrations (60 to 2400 mg/L) was studied. The experiment was performed in a lab-scale up-flow multistage anaerobic reactor (UMAR) inoculated with granular sludge, and operated for 160 days at a constant organic loading rate of 6 kg COD/(m3·d). Treatment of BSW with 60 to 800 mg Ca2+/L resulted in 80.7 to 82.7% of COD removal, 161 to 232.7 mg COD/L of volatile fatty acid (VFA) yield, 0.56 to 0.79 m3/(kgCOD·d) of biogas production rate, and 2.4 to 2.66 m3/(m3·d) of volume loading rate (VLR). The pH remained within the optimal range for anaerobic digestion (adjust to pH = 6.8 to 7.0). The VFAs were composed of 77 to 85% acetic acid, 8.4 to 13.2% butyric acid, and 6.6 to 9.6% propionic acid. At higher influent calcium concentrations (> 800 mg/L), the hydrolysis process appeared to be inhibited, affecting the anaerobic digestion performance of the reactor. In particular, the COD removal efficiency decreased to 55.5%, and the VFA content in the effluent significantly increased due to the lower pH. Microbial community analysis showed that at the end of anaerobic digestion, the Syntrophobacter disappeared, and Clostridium and Anerolineaceae were the main genus and family, respectively. Overall, the results indicated that low calcium (< 300 mg/L) had a positive effect on the UMAR performance.


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.


2016 ◽  
Vol 74 (7) ◽  
pp. 1509-1517 ◽  
Author(s):  
Linan Zhu ◽  
Hailing He ◽  
Chunli Wang

The hybrid membrane bioreactor (HMBR) has been applied in ship domestic sewage treatment under high volumetric loading for ship space saving. The mechanism and influence factors on the efficiency, including hydraulic retention time (HRT), dissolved oxygen (DO) of chemical oxygen demand (COD) removal were investigated. The HMBR's average COD removal rate was up to 95.13% on volumetric loading of 2.4 kgCOD/(m3•d) and the COD concentration in the effluent was 48.5 mg/L, far below the International Maritime Organization (IMO) discharge standard of 125 mg/L. DO had a more remarkable effect on the COD removal efficiency than HRT. In addition, HMBR revealed an excellent capability of resisting organics loading impact. Within the range of volumetric loading of 0.72 to 4.8 kg COD/(m3•d), the effluent COD concentration satisfied the discharge requirement of IMO. It was found that the organics degradation in the aeration tank followed the first-order reaction, with obtained kinetic parameters of vmax (2.79 d−1) and Ks (395 mg/L). The original finding of this study had shown the effectiveness of HMBR in organic contaminant degradation at high substrate concentration, which can be used as guidance in the full scale of the design, operation and maintenance of ship domestic sewage treatment devices.


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


Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2392 ◽  
Author(s):  
Marcin Dębowski ◽  
Marcin Zieliński ◽  
Marta Kisielewska ◽  
Joanna Kazimierowicz

The aim of this study was the performance evaluation of anaerobic digestion of dairy wastewater in a multi-section horizontal flow reactor (HFAR) equipped with microwave and ultrasonic generators to stimulate biochemical processes. The effects of increasing organic loading rate (OLR) ranging from 1.0 g chemical oxygen demand (COD)/L·d to 4.0 g COD/L·d on treatment performance, biogas production, and percentage of methane yield were determined. The highest organic compounds removals (about 85% as COD and total organic carbon—TOC) were obtained at OLR of 1.0–2.0 g COD/L·d. The highest biogas yield of 0.33 ± 0.03 L/g COD removed and methane content in biogas of 68.1 ± 5.8% were recorded at OLR of 1.0 g COD/L·d, while at OLR of 2.0 g COD/L·d it was 0.31 ± 0.02 L/COD removed and 66.3 ± 5.7%, respectively. Increasing of the OLR led to a reduction in biogas productivity as well as a decrease in methane content in biogas. The best technological effects were recorded in series with an operating mode of ultrasonic generators of 2 min work/28 min break. More intensive sonication reduced the efficiency of anaerobic digestion of dairy wastewater as well as biogas production. A low nutrient removal efficiency was observed in all tested series of the experiment, which ranged from 2.04 ± 0.38 to 4.59 ± 0.68% for phosphorus and from 9.67 ± 3.36 to 20.36 ± 0.32% for nitrogen. The effects obtained in the study (referring to the efficiency of wastewater treatment, biogas production, as well as to the results of economic analysis) proved that the HFAR can be competitive to existing industrial technologies for food wastewater treatment.


Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1803 ◽  
Author(s):  
Yuko Goto ◽  
Naoko Yoshida

Conventional aerobic treatment of swine wastewater, which generally contains 4500–8200 mg L−1 of organic matter, is energy-consuming. The aim of this study was to assess the application of scaled-up microbial fuel cells (MFCs) with different capacities (i.e., 1.5 L, 12 L, and 100 L) for removing organic matter from swine wastewater. The MFCs were single-chambered, consisting of an anode of microbially reduced graphene oxide (rGO) and an air-cathode of platinum-coated carbon cloth. The MFCs were polarized via an external resistance of 3–10 Ω for 40 days for the 1.5 L-MFC and 120 days for the 12L- and 100 L-MFC. The MFCs were operated in continuous flow mode (hydraulic retention time: 3–5 days). The 100 L-MFC achieved an average chemical oxygen demand (COD) removal efficiency of 52%, which corresponded to a COD removal rate of 530 mg L−1 d−1. Moreover, the 100 L-MFC showed an average and maximum electricity generation of 0.6 and 2.2 Wh m−3, respectively. Our findings suggest that MFCs can effectively be used for swine wastewater treatment coupled with the simultaneous generation of electricity.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Ali Baddouh ◽  
Brahim El Ibrahimi ◽  
Elhassan Amaterz ◽  
M. Mohamed Rguiti ◽  
Lahcen Bazzi ◽  
...  

The electrochemical oxidation of the Rhodamine B dye (Rh-B) was carried out using dimensionally stable type anode (DSA, Ti/Ru0.3Ti0.7O2). The work was performed using the electrochemical flow cell system. The effect of several operating factors, such as supporting electrolytes, current density, electrolysis time, temperature, and initial concentration of Rh-B dye, were investigated. The UV-visible spectroscopy and chemical oxygen demand (COD) measurements were conducted to monitor the removal and degradation of Rh-B. The best color removal achieved was found to be 98.3% after 10 min applying 3.9 mA·cm−2 as a current density using 0.07 mol·L−1 of NaCl. Meanwhile, the highest COD removal rate (93.0%) was obtained for an applied current density of 3.9 mA·cm−2 as the optimal operating condition after 180 min reaction time, with 2.98 kW h·m−3 as energy consumption. This shows that the best conditions for color removal are not certainly the same as those for the COD removal. The rises in the concentration of NaCl, and applied current increased the Rh-B color removal rate. The decline in Rh-B dye concentration followed pseudo-first-order kinetics. The obtained values of apparent rate constant were increased by increasing chloride ion concentration. It is concluded that the electro-oxidation on DSA electrode using a flow cell is a suitable process for the removal of Rh-B dye in aqueous solutions.


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