Impact of lockdown associated with COVID19 on air quality and emissions from transportation sector: case study in selected Indian metropolitan cities.

This study examines the impact of air quality in selected Indian metropolitan cities during the COVID19 pandemic lockdown period. Concentrations of air quality parameters such as PM, NO, SO, and CO during the transition to lockdown and the actual lockdown period were compared with business as usual periods (a period prior to COVID19 lockdown and a corresponding period in 2019) to estimate the reduction in emission in four major IT hubs in India namely Bengaluru, Chennai, Hyderabad and Pune. A 40-45% reduction in PM concentration was observed, in these cities, during the lockdown compared to the corresponding period in 2019 and a 20-45% reduction was observed compared to business as usual period in 2020.

Effect of selenate and thiosulfate on anaerobic methanol degradation using activated sludge.

Anaerobic bioconversion of methanol was tested in the presence of selenate (SeO), thiosulfate (SO), and sulfate (SO) as electron acceptors. Complete SeO reduction occurred at COD:SeO ratios of 12 and 30, whereas ~ 83% reduction occurred when the COD:SeO ratio was 6. Methane production did not occur at the three COD:SeO ratios investigated.

Volatile fatty acid production from Kraft mill foul condensate in upflow anaerobic sludge blanket reactors.

The utilization of foul condensate (FC) collected from a Kraft pulp mill for the anaerobic production of volatile fatty acids (VFA) was tested in upflow anaerobic sludge blanket (UASB) reactors operated at 22, 37 and 55°C at a hydraulic retention time (HRT) of ∼75 h. The FC consisted mainly of 11370, 500 and 592 mg/L methanol, ethanol and acetone, respectively. 42-46% of the organic carbon (methanol, ethanol and acetone) was utilized in the UASB reactors operated at an organic loading of ∼8.

Bioreduction of selenate in an anaerobic biotrickling filter using methanol as electron donor.

The anaerobic bioreduction of selenate, fed in step (up to 60 mg.L) or continuous (∼7 mg.L) trickling mode, in the presence of gas-phase methanol (4.

Performance of a biotrickling filter for the anaerobic utilization of gas-phase methanol coupled to thiosulphate reduction and resource recovery through volatile fatty acids production.

The anaerobic removal of continuously fed gas-phase methanol (2.5-30 g/m.h) and the reduction of step-fed thiosulphate (1000 mg/L) was investigated in a biotrickling filter (BTF) operated for 123 d at an empty bed residence time (EBRT) of 4.