Abstract: Distillery wastewater in the form of spent wash is a complex and strong industrial effluent, with high load of organic pollutants that may deplete dissolved oxygen on being discharged into aquatic systems and contaminate groundwater by leaching of pollutants, while untreated spent wash disposed on land acidifies the soil. Stringent legislative measures have therefore been framed in different countries for discharge standards of distillery effluent. Utilising the organic pollutants present in various types of wastes as food by mixed microbial populations is emerging as an eco-friendly approach in the recent years, in which complex organic matter is converted into simpler forms, and simultaneously useful gases are produced as renewable and clean energy sources. In the present study, wastewater from a rice bran based distillery has been used as the substrate in a dark fermenter, and native microbial consortium from the digester sludge has been used as the inoculum to treat the wastewater and produce hydrogen. After optimising the operational conditions in batch reactors, sequential batch mode and continuous flow stirred tank reactors were used to study the best operational conditions for enhanced and sustained hydrogen production and removal of pollutants. Since the rate of hydrogen production by the microbial consortium during dark fermentation is influenced by concentration of organic matter, pH and temperature, these operational conditions were optimised in batch mode studies. Maximum hydrogen production rate (347.87ml/L/d) was attained in 32h dark fermentation while a good proportion of COD also got removed from the wastewater. Slightly acidic initial pH seemed to favor biohydrogen production. In continuous stirred tank reactor, high H2 production from distillery wastewater was obtained from a relatively shorter substrate retention time (SRT) of 48h and a moderate organic loading rate (OLR) of 172 g/l/d COD.
Abstract: In Jordan having deficit atmospheric precipitation, an
increase in water demand occurs during summer months. Jordan can
be regarded with a relatively high potential for wastewater recycling
and reuse. The main purpose of this paper was to investigate the
removal of total suspended solids (TSS) and chemical oxygen
demand (COD) for olive mill wastewater (OMW) by
electrocoagulation (EC) process. In the combination of
electrocoagulation by using coupled iron–aluminum electrodes, the
optimum working pH was found to be around 6. Results indicated
that the electrocoagulation process allowed removal of TSS and COD
of about 82.5% and 47.5%, respectively at 45 mA/cm2 after 70
minutes by using coupled iron–aluminum electrodes. It was
demonstrated that the maximum TSS and COD removals were
obtained at some optimum experimental parameters for current
density, pH, and reaction time.
Abstract: This research involves the design and analysis of pinch-based water/wastewater networks to minimize water utility in the petrochemical and petroleum industries. A study has been done on Tehran Oil Refinery to analyze feasibilities of regeneration, reuse and recycling of water network. COD is considered as a single key contaminant. Amount of freshwater was reduced about 149m3/h (43.8%) regarding COD. Re-design (or retrofitting) of water allocation in the networks was undertaken. The results were analyzed through graphical method and mathematical programming technique which clearly demonstrated that amount of required water would be determined by mass transfer of COD.
Abstract: Nowadays, the increase of human population every
year results in increasing of water usage and demand. Saen Saep
canal is important canal in Bangkok. The main objective of this study
is using Artificial Neural Network (ANN) model to estimate the
Chemical Oxygen Demand (COD) on data from 11 sampling sites.
The data is obtained from the Department of Drainage and Sewerage,
Bangkok Metropolitan Administration, during 2007-2011. The
twelve parameters of water quality are used as the input of the
models. These water quality indices affect the COD. The
experimental results indicate that the ANN model provides a high
correlation coefficient (R=0.89).
Abstract: Sampling and analysis of leachate from Bhalaswa
landfill and groundwater samples from nearby locations, clearly
indicated the likely contamination of groundwater due to landfill
leachate. The results of simulation studies carried out for the
migration of Chloride from landfill shows that the simulation results
are in consonance with the observed concentration of Chloride in the
vicinity of landfill facility. The solid waste disposal system presently
being practiced in Delhi consists of mere dumping of wastes
generated, at three locations Bhalaswa, Ghazipur, and Okhla without
any regard to proper care for the protection of surrounding
environment. Bhalaswa landfill site in Delhi, which is being operated
as a dump site, is expected to become cause of serious groundwater
pollution in its vicinity. The leachate from Bhalaswa landfill was
found to be having a high concentration of chlorides, as well as DOC,
COD. The present study was undertaken to determine the likely
concentrations of principle contaminants in the groundwater over a
period of time due to the discharge of such contaminants from
landfill leachates to the underlying groundwater. The observed
concentration of chlorides in the groundwater within 75m of the
radius of landfill facility was found to be in consonance with the
simulated concentration of chloride in groundwater considering one
dimensional transport model, with finite mass of contaminant source.
Governing equation of contaminant transport involving advection and
diffusion-dispersion was solved in matlab7.0 using finite difference
method.
Abstract: Biological Ammonia removal (nitrification), the
oxidation of ammonia to nitrate catalyzed by bacteria, is a key part of
global nitrogen cycling. In the first step of nitrification,
chemolithoautotrophic ammonia oxidizer transform ammonia to
nitrite, this subsequently oxidized to nitrate by nitrite oxidizing
bacteria. This process can be affected by several factors. In this study
the effect of influent COD on biological ammonia removal in a
bench-scale biological reactor was investigated. Experiments were
carried out using synthetic wastewater. The initial ammonium
concentration was 25mgNH4
+-N L-1. The effect of COD between
247.55±1.8 and 601.08±3.24mgL-1 on biological ammonia removal
was investigated by varying the COD loading supplied to reactor.
From the results obtained in this study it could be concluded in the
range of 247.55±1.8 to 351.35±2.05mgL-1, there is a direct
relationship between amount of COD and ammonia removal.
However more than 351.35±2.05 up to 601.08±3.24mgL-1 were
found an indirect relationship between them.