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: This work aims to assess the quality of water dams based on the monitoring of physical-chemical parameters by the National Agency of Water Resources (ANRH) for a period of 10 years (1999-2008). Quality sheets of surface water for the four dams in the region of upper Cheliff (Ghrib, Deurdeur, Harreza, and Ouled Mellouk) show a degradation of the quality (organic pollution expressed in COD and OM) over time. Indeed, the registered amount of COD often exceeds 50 mg/ l, and the OM exceeds 15 mg/l. This pollution is caused by discharges of wastewater and eutrophication. The waters of dams show a very high salinity (TDS = 2574 mg/l in 2008 for the waters of the dam Ghrib, standard = 1500 mg/l). The concentration of nitrogenous substances (NH4+, NO2-) in water is high in 2008 at Ouled Melloukdam. This pollution is caused by the oxidation of nitrogenous organic matter. On the other hand, we studied the relationship between the evolution of quality parameters and filling dams. We observed a decrease in the salinity and COD following an improvement of the filling state of dams, this resides in the dilution water through the contribution of rainwater. While increased levels of nitrates and phosphorus in the waters of four dams studied during the rainy season is compared to the dry period, this increase may be due to leaching from fertilizers used in agricultural soils situated in watersheds.
Abstract: Activated carbon is an amorphous carbon chain which
has extremely extended surface area. High surface area of activated
carbon is due to the porous structure. Activated carbon, using a
variety of materials such as coal and cellulosic materials; can be
obtained by both physical and chemical methods. The prepared
activated carbon can be used for decolorize, deodorize and also can
be used for removal of organic and non-organic pollution. In this
study, pomegranate peel was subjected to 800W microwave power
for 1 to 4 minutes. Also fresh pomegranate peel was used for the
reference material. Then ZnCl2 was used for the chemical activation
purpose. After the activation process, activated pomegranate peels
were used for the adsorption of Zn metal (40 ppm) in the waste water.
As a result of the adsorption experiments, removal of heavy metals
ranged from 89% to 85%.
Abstract: Macro invertebrates have been used to monitor
organic pollution in rivers and streams. Several biotic indices based
on macro invertebrates have been developed over the years including
the Biological Monitoring Working Party (BMWP). A new biotic
index, the Gammarus:Asellus ratio has been recently proposed as an
index of organic pollution. This study tested the validity of the
Gammarus:Asellus ratio as an index of organic pollution, by
examining the relationship between the Gammarus:Asellus ratio and
physical chemical parameters, and other biotic indices such as
BMWP and, Average Score Per Taxon (ASPT) from lakes and
streams at Markeaton Park, Allestree Park and Kedleston Hall,
Derbyshire. Macro invertebrates were sampled using the standard
five minute kick sampling techniques physical and chemical
environmental variables were obtained based on standard sampling
techniques. Eighteen sites were sampled, six sites from Markeaton
Park (three sites across the stream and three sites across the lake). Six
sites each were also sampled from Allestree Park and Kedleston Hall
lakes. The Gammarus:Asellus ratio showed an opposite significant
positive correlations with parameters indicative of organic pollution
such as the level of nitrates, phosphates, and calcium and also
revealed a negatively significant correlations with other biotic indices
(BMWP/ASPT). The BMWP score correlated positively significantly
with some water quality parameters such as dissolved oxygen and
flow rate, but revealed no correlations with other chemical
environmental variables. The BMWP score was significantly higher
in the stream than the lake in Markeaton Park, also The ASPT scores
appear to be significantly higher in the upper Lakes than the middle
and lower lakes. This study has further strengthened the use of
BMWP/ASPT score as an index of organic pollution. But additional
application is required to validate the use of Gammarus:Asellus as a
rapid bio monitoring tool.