Rubia Zahid Gaur

Sustainable Post Treatment Options of Anaerobic Effluent

The strategy of treating sewage by the common and known aerobic process has been shifted back to anaerobic processes in the recent years with the advent of high rate anaerobic systems such as up-flow anaerobic sludge blanket reactor (UASB), anaerobic contact process, anaerobic filter (AF) or fixed film reactors and fluidized bed reactors. The high rate anaerobic processes, like UASB have several advantages such as low capital, operation and maintenance costs, energy recovery in the form of biogas, operational simplicity, low energy consumption, and low production of digested sludge (van Haandel & Lettinga, 1994; Gomec, 2010; Khan et al., 2011a).

Impairment in water quality of Ganges River and consequential health risks on account of mass ritualistic bathing

Abstract Effect of mass ritualistic bathing was studied on the water quality of Ganges River during Maha Kumbh festival in India. Significantly higher values of biochemical oxygen demand (BOD) (14 mg/L), chemical oxygen demand (67 mg/L), total suspended solids (55 mg/L), and ammonia nitrogen (2.15 mg/L) were observed during mass ritualistic bathing. The BOD values were observed to surpass the standard BOD criteria ( 3 mg/L) of outdoor bathing. Similarly, higher number of total coliforms (792 most probable numbers [MPN]/100 mL) and fecal coliforms (482 MPN/100 mL) were observed in water samples, which show the alarming level of fecal contamination according to Indian and European (100 MPN/100 mL) standards of outdoor bathing. Furthermore, total 5,368 cases of water borne infections were observed during the epidemiological survey. In order to protect the public health and water quality of river, it is recommended to strictly regulate the bathing practices with continuous disinfection at upstream of bathing ...

Fecal coliform removal from the effluent of UASB reactor through diffused aeration

Abstract Although UASB systems treating municipal wastewater generally remove fecal coliform (FC) by ∼ one order of magnitude, the effl uent still contains concentrations higher than the WHO standard for unrestricted irrigation. In this study, the effect of continuous diffused aeration on the removal of FC was examined. The diffused aeration system was operated at different hydraulic retention times (60, 30 and 15 min) and dissolved oxygen (DO) concentrations (5−6 and 1−2 mg/l). The removal of FC was affected by the applied HRT and DO. Optimum results were obtained at HRT and DO equal to 60 min and 5−6 mg/l respectively, with FC removal of approximately 2 log (97%). The mechanisms responsible for FC die-off were the pH and oxidation reduction potential (ORP) of the medium.

Impact of Varied Ratio of Duckweed ( Spirodela polyrhiza ) and Waste-Activated Sludge on Anaerobic Digestion

In this study, duckweed (Spirodela polyrhiza) and waste-activated sludge (WAS) were co-digested in different proportions with acclimatized anaerobic granular sludge (AAGS) in mesophilic conditions. The aim was to evaluate if the co-digestion could lead to an increased efficiency of methane production compared to digestion of waste-activated sludge alone. Results indicate that co-digestion with both duckweed and WAS, in certain proportions, i.e., T4, increased the methane generation compared with digestion at other proportions. The methane generation yield in treatment setup T4 was significantly higher than the calculated in many of the proportion. The Gompertz model fits well on the experimental data of the treatment setup T4. The values of correlation coefficient were achieved relatively higher (R2 ≥ 0.99). The trend of methane generation was not obsevred similar for the co-digestion of duckweed with WAS in the without pretreated samples.

Operation and maintenance of sewerage systems: present challenges and possible solutions—an Indian experience

A strong focus on increasing gross domestic product to meet demanding needs stretched the country on the brink of overstretching the ecological carrying capacity. Unfortunately, rivers are among th...