Skilled and experienced MSc in civil and environmental engineering with a proven track record of site experiences. Area of expertise: • Waste and environmental management • Anaerobic digestion technology in organic-wastes and wastewater treatment • Optimizing and developing anaerobic system toward the higher organic load
Trace elements play an indispensable role in stabilizing the performance of anaerobic co-digestio... more Trace elements play an indispensable role in stabilizing the performance of anaerobic co-digestion (Co-AD) of food waste (FW) and sewage sludge (SS) at greater organic load (OL). The results of high organic-loaded reactors showed that the stability of the system failed due to the buildup of volatile fatty acid (VFA) and ammonia. At the OL of 6.5 g/L, the stability of the system failed due to the buildup of propionic acid. The optimum dosage of Fe (5000 mg/L), Ni (200 mg/L), Zn (320 mg/L), and Mo (2.2 mg/L) was experimentally determined and added to reduce the inhibition condition. Consequently, the propionic acid concentration, which was above 1500 mg/L reduced to under 500 mg/L during Co-AD. Hence, higher biogas production, and biodegradability of 236 ± 23 mL/g VS, and 41.75%, respectively, were obtained. Increasing OL (9.5 g/L), the stability of the system was hindered due to only the buildup of ammonia (up to 188 ± 6 NH 3-N mg/L). Therefore, the trace elements of Cu (250 mg/L) and Co (3 mg/ L) were experimentally determined and added into the Co-AD to diminish ammonia accumulation and process instability. The experimental results showed that at OL of 14 g/L, biogas production, low ammonia concentration and biodegradability of 332 ± 21 mL/g VS, and 70 NH3-N mg/L, and 57.89%, respectively, were achieved. However, the performance and stability of the system failed at the higher OL due to the more increased ammonia and VFA concentration, and the greater dosages of trace elements did not enhance the process stability.
The aim of this study was to evaluate the performance of anaerobic co-digestion of food waste (FW... more The aim of this study was to evaluate the performance of anaerobic co-digestion of food waste (FW) and sewage sludge (SS) at high organic load with the aid of an inorganic adsorbent supplementary. From BMP tests of seven mesophilic reactors, it was found that the stability of the system was hindered at higher organic load due to low alkalinity capacity of sludge (1600 mg/L) and excessive accumulation of inhibitory substances such as free ammonia and VFA. Thus, the low-cost adsorbent was applied to enhance the digestion process stability at high organic load (12.8 g VS/L). The results showed that addition of 1 g of sorghum-based activated carbon (SAC) (4 g TS/L) stabilized the system, reduced ammonia and T-VFA concentration from 267 to 39 mg/L, and 1300 to under 600 mg/L, respectively. Consequently, the methane yield increased from 201 to 272 mL/g VS (35%), solid retention time (SRT) reduced by 34%, and T-COD removal achieved by 79.38%. However, with a further increase of SAC the biogas generation decreased due to excessive adsorption of VFAs.
Trace elements play an indispensable role in stabilizing the performance of anaerobic co-digestio... more Trace elements play an indispensable role in stabilizing the performance of anaerobic co-digestion (Co-AD) of food waste (FW) and sewage sludge (SS) at greater organic load (OL). The results of high organic-loaded reactors showed that the stability of the system failed due to the buildup of volatile fatty acid (VFA) and ammonia. At the OL of 6.5 g/L, the stability of the system failed due to the buildup of propionic acid. The optimum dosage of Fe (5000 mg/L), Ni (200 mg/L), Zn (320 mg/L), and Mo (2.2 mg/L) was experimentally determined and added to reduce the inhibition condition. Consequently, the propionic acid concentration, which was above 1500 mg/L reduced to under 500 mg/L during Co-AD. Hence, higher biogas production, and biodegradability of 236 ± 23 mL/g VS, and 41.75%, respectively, were obtained. Increasing OL (9.5 g/L), the stability of the system was hindered due to only the buildup of ammonia (up to 188 ± 6 NH 3-N mg/L). Therefore, the trace elements of Cu (250 mg/L) and Co (3 mg/ L) were experimentally determined and added into the Co-AD to diminish ammonia accumulation and process instability. The experimental results showed that at OL of 14 g/L, biogas production, low ammonia concentration and biodegradability of 332 ± 21 mL/g VS, and 70 NH3-N mg/L, and 57.89%, respectively, were achieved. However, the performance and stability of the system failed at the higher OL due to the more increased ammonia and VFA concentration, and the greater dosages of trace elements did not enhance the process stability.
The aim of this study was to evaluate the performance of anaerobic co-digestion of food waste (FW... more The aim of this study was to evaluate the performance of anaerobic co-digestion of food waste (FW) and sewage sludge (SS) at high organic load with the aid of an inorganic adsorbent supplementary. From BMP tests of seven mesophilic reactors, it was found that the stability of the system was hindered at higher organic load due to low alkalinity capacity of sludge (1600 mg/L) and excessive accumulation of inhibitory substances such as free ammonia and VFA. Thus, the low-cost adsorbent was applied to enhance the digestion process stability at high organic load (12.8 g VS/L). The results showed that addition of 1 g of sorghum-based activated carbon (SAC) (4 g TS/L) stabilized the system, reduced ammonia and T-VFA concentration from 267 to 39 mg/L, and 1300 to under 600 mg/L, respectively. Consequently, the methane yield increased from 201 to 272 mL/g VS (35%), solid retention time (SRT) reduced by 34%, and T-COD removal achieved by 79.38%. However, with a further increase of SAC the biogas generation decreased due to excessive adsorption of VFAs.
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Papers by mohammad javad bardi
at high organic load with the aid of an inorganic adsorbent supplementary. From BMP tests of seven mesophilic reactors,
it was found that the stability of the system was hindered at higher organic load due to low alkalinity capacity of sludge
(1600 mg/L) and excessive accumulation of inhibitory substances such as free ammonia and VFA. Thus, the low-cost
adsorbent was applied to enhance the digestion process stability at high organic load (12.8 g VS/L). The results showed that
addition of 1 g of sorghum-based activated carbon (SAC) (4 g TS/L) stabilized the system, reduced ammonia and T-VFA
concentration from 267 to 39 mg/L, and 1300 to under 600 mg/L, respectively. Consequently, the methane yield increased
from 201 to 272 mL/g VS (35%), solid retention time (SRT) reduced by 34%, and T-COD removal achieved by 79.38%.
However, with a further increase of SAC the biogas generation decreased due to excessive adsorption of VFAs.
at high organic load with the aid of an inorganic adsorbent supplementary. From BMP tests of seven mesophilic reactors,
it was found that the stability of the system was hindered at higher organic load due to low alkalinity capacity of sludge
(1600 mg/L) and excessive accumulation of inhibitory substances such as free ammonia and VFA. Thus, the low-cost
adsorbent was applied to enhance the digestion process stability at high organic load (12.8 g VS/L). The results showed that
addition of 1 g of sorghum-based activated carbon (SAC) (4 g TS/L) stabilized the system, reduced ammonia and T-VFA
concentration from 267 to 39 mg/L, and 1300 to under 600 mg/L, respectively. Consequently, the methane yield increased
from 201 to 272 mL/g VS (35%), solid retention time (SRT) reduced by 34%, and T-COD removal achieved by 79.38%.
However, with a further increase of SAC the biogas generation decreased due to excessive adsorption of VFAs.