D. V. S. Murthy

Bio: D. V. S. Murthy is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Trickling filter & Effluent. The author has an hindex of 7, co-authored 8 publications receiving 118 citations.

Bioaugmentation and anaerobic treatment of pharmaceutical effluent in fluidized bed reactor.

Abstract: The start-up of an anaerobic fluidized bed reactor was carried out using a single inoculum (supernatant of anaerobic digester) and later on with multiple inoculum (a mixture of supernatant of anaerobic digester and volatile fatty acid (VFA)) to achieve a faster start-up. Then regular experiments were carried out to study the effect of hydraulic retention time (HRT) on COD removal (%) and biogas production. The pharmaceutical effluent with COD of 2000 to 4000 mg/L was treated in a fluidized bed reactor using an enricher-reactor concept with a hydraulic retention times of 3 (Uf = 6 Umf) to 24 (Uf = 1.5 Umf) hr. The maximum COD removal (%) of 91.2 and a maximum biogas production of 5.62 L/d were obtained at 24 hr HRT for a maximum COD concentration of 4000 mg/L corresponding to a fluidization velocity (Uf) of 20 m/hr (1.5 Umf) using a granular activated carbon bed of average size 700 microns.

Synthetic dairy wastewater treatment using cross flow medium trickling filter

Abstract: The treatment of synthetic dairy wastewater was carried out using cross flow medium trickling filter of specific surface area 243 m2/m3. The operating variables in this study were hydraulic and organic loading rates. The hydraulic loadings employed in this study were 5, 9, 13 and 17 m3/m2.d for the influent COD concentrations of 427 to 1384 mg/l. It was observed that the relationship between organic removal rate and organic loading rate showed two regions of linear behaviour with the point of inflection at an organic loading rate of 26 g COD/m2.d. Kornegay model was used to evaluate the kinetic coefficients for the system. The results were found to be satisfactory.

Comparison of the trickling filter models for the treatment of synthetic dairy wastewater

Abstract: This paper describes the design implications of four existing trickling filter models. Experimental data from the treatment of synthetic dairy wastewater was used to evaluate the kinetic parameters. The four trickling filter models were examined for their ability to model the present data. Among the four models studied, Kincannon and Stover model based on the independent variable of surface organic loading rate gave superior results compared to other models.

Colour removal from bagasse-based pulp mill effluent using a white rot fungus

Abstract: Colour removal of pulp plant effluent was studied using white rot fungus, Trametes (Coriolus) versicolor The batch experiments were carried out using fungus in the form of mycelial pellets In the present investigation, the effect of pH, concentrations of glucose (substrate), initial effluent colour and ammonium chloride (nutrient) on colour removal efficiency were studied It was found that the maximum colour removal efficiency of 825% was obtained with an optimal glucose and ammonium chloride concentrations of 15 g/l and 05 g/l respectively at a pH of 45 without diluting the effluent

Bioaugmentation of syntrophic acetate-oxidizing culture in biogas reactors exposed to increasing levels of ammonia.

Abstract: The importance of syntrophic acetate oxidation for process stability in methanogenic systems operating at high ammonia concentrations has previously been emphasized. In this study we investigated bioaugmentation of syntrophic acetate-oxidizing (SAO) cultures as a possible method for decreasing the adaptation period of biogas reactors operating at gradually increased ammonia concentrations (1.5 to 11 g NH4+-N/liter). Whole stillage and cattle manure were codigested semicontinuously for about 460 days in four mesophilic anaerobic laboratory-scale reactors, and a fixed volume of SAO culture was added daily to two of the reactors. Reactor performance was evaluated in terms of biogas productivity, methane content, pH, alkalinity, and volatile fatty acid (VFA) content. The decomposition pathway of acetate was analyzed by isotopic tracer experiments, and population dynamics were monitored by quantitative PCR analyses. A shift in dominance from aceticlastic methanogenesis to SAO occurred simultaneously in all reactors, indicating no influence by bioaugmentation on the prevailing pathway. Higher abundances of Clostridium ultunense and Tepidanaerobacter acetatoxydans were associated with bioaugmentation, but no influence on Syntrophaceticus schinkii or the methanogenic population was distinguished. Overloading or accumulation of VFA did not cause notable dynamic effects on the population. Instead, the ammonia concentration had a substantial impact on the abundance level of the microorganisms surveyed. The addition of SAO culture did not affect process performance or stability against ammonia inhibition, and all four reactors deteriorated at high ammonia concentrations. Consequently, these findings further demonstrate the strong influence of ammonia on the methane-producing consortia and on the representative methanization pathway in mesophilic biogas reactors.

Relating Anaerobic Digestion Microbial Community and Process Function

Abstract: Anaerobic digestion (AD) involves a consortium of microorganisms that convert substrates into biogas containing methane for renewable energy. The technology has suffered from the perception of being periodically unstable due to limited understanding of the relationship between microbial community structure and function. The emphasis of this review is to describe microbial communities in digesters and quantitative and qualitative relationships between community structure and digester function. Progress has been made in the past few decades to identify key microorganisms influencing AD. Yet, more work is required to realize robust, quantitative relationships between microbial community structure and functions such as methane production rate and resilience after perturbations. Other promising areas of research for improved AD may include methods to increase/control (1) hydrolysis rate, (2) direct interspecies electron transfer to methanogens, (3) community structure–function relationships of methanogens, (4) methanogenesis via acetate oxidation, and (5) bioaugmentation to study community–activity relationships or improve engineered bioprocesses.

Removal of ammonium, iron and manganese from potable water in biofiltration units: a review

Abstract: Ammonium, and trace metals such as iron and manganese are common inorganic pollutants present in waters. Several surface and groundwaters contain natural or increased concentrations of these pollutants that are observed either isolated or in pairs, or all three together. Although several processes have been established for the biological removal of one of the above-mentioned pollutants, only recently have important studies been performed on the efficient and cost-effective simultaneous biological removal of two or more substances. This paper reviews the variety of full- and pilot-scale biological filters that have been used for combined or simultaneous biological removal, as well as factors and conditions that were found to affect the process. The main results regarding research progress on combined or simultaneous biological removal are evaluated. Finally, the kinetic models and simulation approaches used are discussed. © 2013 Society of Chemical Industry