dc.description.abstract |
Water quality of natural rivers and streams are becoming worst due to highly
contaminated effluent in developing countries. In Pakistan, natural streams are presenting
dramatic scenario along with deadly environmental conditions. Considering the water
pollution issues and increasing demand of water, it is truly required to manage all these
things on priority basis. In case of developing countries like Pakistan where there are
severe financial constraints, it is necessary to formulate such tactics for water quality
management which would maintain acceptable stream water standards. Considering the
negative impacts on the environment due to dispose of untreated effluent, it is seriously
required to plan environmental management for all natural rivers and streams.
Environmental impacts of untreated effluent on “Ravi River” water quality have been
taken up for investigation. Untreated effluents from the city of Lahore and it suburbs are
seriously polluting “Ravi River”. The river section between “Ravi Syphon” and
“Balloki” is presenting the most horrible scene, where industrial effluents from
“Hudira” and “Deg Nallah” are also joining the river. In this segment the river water is
being used for irrigation and livestock purposes. Considering the pollution scenario, more
expansive effluent treatment systems will be required to maintain environmental
standards of this river. It is concluded that due to high rate untreated effluent “Ravi
River” is acting as a wastewater carrier.
The study propagates different reasons for the surface water quality degradation in
Pakistan. Mixing of untreated effluent in large quantity to “Ravi River” is a serious threat
to the environment and public health. Surface water quality parameters like, Biological
Oxyen Demand (BOD), Dissolve Oxygen (DO), Chemical Oxygen Demand (COD),
Suspended Solids, Phosphorus, Chloride, Sodium, Total Kjeldahls,Nitrogen (TKN),
Nitrate, Nitrites, Oil & Grease and Total Coliforms were measured on selected sampling
stations for the period of three years. Laboratory results of collected samples are not
satisfactory. To investigate the impacts of untreated effluent on microbial activities a
biological survey was also carried out. Species of fish, oligochaetes, algae, stone fly,
midge, and cadesfly were identified and discussed. It was investigated that during winter
the river seems to be quite polluted. However conditions become better during summer
VIAbstract
months due to the increase in the flow rate. High concentration of wastewater microbes
clearly explains that water quality of “Ravi River” is not satisfactory.
Modeling of wastewater treatment process has gained much attention and a lot of
research has been focused toward this area. Basic Activated Sludge Models (ASM)
developed by International Water Association (IWA) task group are contributing
considerably in wastewater treatment modeling. Different factors related to the model
performance like model selection, model functions and model calibration are discussed in
detail to support the effluent treatment process in Pakistan. The applications of ASM1,
ASM2, ASM2d, ASM3, ASM3_2N, ASM3 bio-P model etc. are also studied. The white-
box modeling techniques in this area are more significant. The importance of black-box
models under special conditions where white-box models are not able to predict accurate
results are also investigated. It was also found that use of hybrid, linearization and
Artificial Intelligence (AI) techniques in wastewater treatment modeling can be more
useful for process optimization and control. White-box modeling techniques in
wastewater treatment modeling are most reliable for better understanding of the whole
mechanism. Model purpose definition plays a vital role in model selection, data
collection and calibration. Black-box modeling techniques can also be encouraged in this
area to avoid wrong predicted results from white-box models under harsh environmental
conditions like heavy rainfall or shock loading.
It was also concluded during the
investigation that hybrid modeling methodologies can be more supportive for process
optimization and supervisory control.
Low flow conditions in river along with high rate of contaminants are also damaging the
ground water quality in the study area. During the study collected data from different
departments, field sampling and field visits clearly narrate that hygienic conditions of
“Ravi River” are becoming worst day by day. These conditions can only be improved by
proper wastewater treatment plans, environmental management and powerful
environmental legislation. |
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