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Study on Water Quality of Bhairab River in Khulna Region
No full textThis thesis is submitted to the Department of Civil Engineering, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Science in Civil Engineering, October 2015.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 74-77).Water is an important element for all living beings on this planet. All life forms of the earth
depend upon water. No life can exist without water since water is as essential for life as air is.
Generally water contains many physical, chemical and biological impurities. Surface water
sources may be mainly in the form of rivers, lakes, pond, glaciers and rainwater. Modem
urbanization, increasing population, household wastes and industrialization day by day are
deteriorating these sources. Bhairab River is not further than the ill concern. It receives huge
quantities of pollutants and thus degrading its water quality gradually. This paper deals with
assessment of water quality of Bhairab River and also its trends.
To fulfill the present aim of the study, a total length of 36.98 Km along the river from Rupsha
ghat to Noapara Bazar ghat was divided into ten sampling stations. Water samples were
collected every month from each of the sampling stations through the year 2014 for
laboratory testing. Twenty water quality parameters such as temperature, pH, turbidity,
conductivity, color, alkalinity, hardness, TS, TDS, SS, phosphate, nitrite, nitrate, chloride,
DO. BOD, COD, manganese, fecal coliform and total coliform were examined by standard
method. Among those twelve were found out of Bangladesh drinking standard. Water quality
assessment was performed by determining water quality index (WQI) following National
Sanitary Foundation (NSF) method. The study analyzed trend of water quality index. Present
research is conducted based on field and secondary data.
In the correlation study it is found that major parameters are more or less correlated with each
other. Three important parameters like chloride, TDS and conductivity each are significantly
correlated with each other. It helps water quality management and monitoring. Average water
quality index obtained for the year 2014 in both temporal (twelve months) and spatial (ten
stations) are 64 and 65. respectively which is close to each other. As per NSF water quality
index range Bhairab River is medium in quality, and this water is not suitable for drinking
without treatment.
The study also reveals that water quality index is progressively decreasing with course of
time. In 2005 water quality index was observed 71 while in 2014 it reduced to 64. During last
ten years WQI is decreased by 7 points, so yearly average decreasing presumed 0.70 point
per year. Following this rate projected water quality index of studied river assumed to be
51.39 and 35.65 for the year 2030 and 3050 respectively. After that water quality turns
medium to bad. This is an alarming for the local environment. Bottom line is that water
quality of Khulna region expressly Bhairab River is being deteriorated day by day.Md. Alhaz UddinMaster of Science in Civil Engineerin
Optimality Analysis on the Basis of Rectangular (Manhattan) Distance Measure for Maximin LHDs Obtained by the Iterated Local Search Heuristics Approach
No full textdc.description This thesis is submitted to the Department of Mathematics, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Philosophy in Mathematics, June 2015.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 82-90).Design of Experiment (DoE) is an important issue for developing mathematical model of
any physical problem especially when there exist large numbers of factors. Optimal Latin
Hypercube Design (LHD) is one of the well-known and used tools among the experimental
designs. For obtaining optimal LHD, Iterated Local Search (ILS) is one of the best way
among the heuristic approaches. Grosso et al. (2009) showed that ILS approach has the
ability to obtain a large number of maximin (Optimizations by maximizing minimum pairwise
distance) LHD where distances are measured in terms of Euclidian distance measure.
Several authors showed that rather than Euclidean distance measure other measures may
suitable for good DoE. Manhattan distance measure is one of them [Morris and Mitchell
(1995)]. In this research work, the main objective is to study the optimality of the maximin
LHD obtained by ILS approach regarding Manhattan distance measure. For this purpose,
ILS approach is implemented in windows environment (rather than Sun cluster, as Gross et
al. (2009) done). Extensive experiments are performed to obtain maximin LHD measured
in Euclidian distance measure. Then further experiments are reformed on those LHDs to
find the minimum pair-wise distance of each LHD measured in Manhattan distance. Those
values are compared with available one in the literature. It is noted that few values
(maximin LHD measured in Manhattan distance measure) are available in the literature. It
seems that the minimum pair-wise distance measured in Manhattan distance measure of the
maximin LHDs obtained by ILS approach, optimized in Euclidian distance measure are
comparable with those maximin LHDs obtained through other approaches but optimized in
the Manhattan distance measure. Moreover some further experiments are performed to find
out some new characteristics of those LHDs which may be used for further study. Some
improved maximin LHDs are also obtained in this experimental arena and are presented in
the thesis.Md. Ishaque AliMaster of Philosophy in Mathematic
Studies on Volumetric and Viscometric Properties of Nitrobenzene and Alkanols Mixtures
No full textThis thesis is submitted to the Department of Chemistry, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Philosophy in Chemistry, December 2015.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 159-166).Densities and viscosities of binary mixtures of Ethanol + Nitrobenzene (NB), n-Propanol + Nitrobenzene (NB), /so-Propanol + Nitrobenzene(NB), n-Butanol + Nitrobenzene (NB), iso- Butanol + Nitrobenzene (NB), n-Amyl alcohol + Nitrobenzene (NB), iso-Amyl alcohol + Nitrobenzene (NB) and Propylene glycol + Nitrobenzene (NB) have been studied over the entire range of composition (0 < x2 < I) at 298.15- 323.15K with an interval of 5K. The density of alcohols in pure state was found to be in the order of
Propylene glycol> n-Amyl alcohol > n-Butanol > n-Propanol > Ethanol
and iso-Amyl alcohol> iso-Butanol > iso-Propanol
The values of densities of Alkanols + NB at equi-mole fraction systems has been found to be in the order of Ethanol+NB> n-Propanol+NB > n-Butanol+NB > n-Amyl alcohol
+NB> Propylene glycol NB and iso-Propanol+NB> iso-Butanol+NB> iso-Amyl alcohol+NB The value of density of Alkanols in NB decreases with the increasing of composition of the Alkanols. The decrease of density with composition of Alkanols can be attributed to solute-solvent interaction. The densities of all Alkanols in pure state increase with the increasing of carbon number which may depend on the molecular weight of alcohols, structural formula and H-bonding of alcohols. The densities decrease regularly with the increasing of temperature. This is due to the thermal agitation and hence the weaker the dipole-dipole interaction or dissociation of H-bonding are occurred. At the 0.5 mole fraction, the density of Ethanol+NB is higher than other higher chain or branched chain Alkanols indicating that the nature of association of NB mostly disrupted in higher or branched chain Alkanols. The excess molar volume, VE for all the systems are positive over the entire range of composition, showing maxima at 0.5-0.8 mole fraction of Alkanols. The values of maxima of VE of Alkanols in NB solutions was found to be in the order of Propylene glycol+NB > n-Amyl alcohol+NB > n-Butanol+NB > n-Propanol+NB > Ethanol+NB and iso-Amyl alcohol+NB > iso-Butanol+N13 > iso-Propanol+NB and iso-Amyl alcohol+NB > n-Amyl alcohol+NB and iso-Butanol+NB > n-Butanol+NB and iso-Propanol+NB > n-Propanol+NB The increasing of VE with carbon chain length of Alkanols may be related to increase of the size of Alkanols. The values of VE for the studied Alkanols increase with the increase of temperature. The observed values of VE for the mixtures have been explained in terms of physical, chemical and geometrical contributions. The viscosity coefficients, ƞ of Alkanols + NB mixtures at six different temperatures have also been determined. The viscosities decrease initially slowly up to ~0.5-0.8 mole fraction of Ethanol, n-Propanol, iso-Propanol, n-Butanol, iso-Butanol, n-Amyl alcohol, iso-Amyl alcohol and Propylene glycol and later on, the viscosity increases sharply until the pure alcohol is reached. The
viscosity of NB + Alkanols mixture at 0.5 mole fraction has been found to be in the order of Propylene glycol + NB> n-Amyl alcohol+ NB> n-Butanol >n-Propanol+ NB > Ethanol+ NB and iso-Amyl alcohol+ NB> iso-Butanol + NB > iso-Propanol+ NB and
iso- Amy1 alcohol + NB > n- Amy1 alcohol + NB and iso-Butanol + NB> n-Butanol + NB and iso-Propanol + NB > n-Propanol + NB There is a marked decrease in the viscosity with increase of temperature for all the studied alcohols. This ascribed that the Alkanols + NB solutions are less stable at higher temperature. The increasing of viscosity with carbon number of Alkanols or branched chain Alkanols ascribed that the solution resistance increases with the increase of carbon chain length or branched chain. The
linear dependence of lnƞ against 1/T shows for the all studied Alkanols + NB mixtures. The branched chain isomers are less stable than linear chain isomer at higher temperature. The excess viscosity, ƞ E values are found to be negative indicating that the Alkanols + NB system are non ideal. Excess viscosities are negative at all the temperatures over the entire range of composition for all the systems with minima occurring between 0.6-0.8 mole fractions. The negative excess viscosity, ƞ E of all the studied Alkanols + NB indicate that the dissociation of components through dispersive forces or steric hindrance. The position of minima virtually does not change remarkably with the variation of temperature. The values of the minima are in the order:
Propylene glycol+NB> n-Amyl alcohol+NB > n-Butanol+NB > n-Propanol+NB > thanol+NB and iso-Amyl alcohol+NB> iso-Butanol+NB > iso-Propanol±NB
and iso-Amyl alcohol+NB > n - Arnyl alcohol+NB and iso-Butanol±NB > n-Butanol+NB and iso-Propanol+NB > n-Propanol+NB The hydrophobic effect increases with the increasing of carbon chain length of alcohols. This indicates that the ƞ E decreases with the decrease of carbon number. The positive VE, negative ƞ E and negative interaction parameter (ɛ) for the studied Alkanols + NB systems indicate that dispersion force is dominant. Some disruptive force causing volume expansion may be present and
it is more than compensated by volume contraction. The thermodynamic parameters such as free energy (∆G*), enthalpy (∆G*), and entropy (∆S*) change of activation for the viscous flow for these systems were examined for the entire range of composition. The free energy (∆G*) were found to be positive in magnitude indicating that the kinetic species involved in forming cavities or holes in the liquid medium is given by the work
required in forming the hole against surface tension of the solution. The negative excess free energy, ∆G*E indicate that the strong dispersion force in Alkanols+ NB solution is dominant. The ∆H* values are positive for all the systems indicate that positive work has to be done to overcome the energy barrier for the flow process. The ∆S* values are found to be very small for all the studied systems indicating that the effects of ∆S* are negligible. The excess properties (VE, ƞ E, ∆G*E) data have been fitted by the least square method to the four parameters Redlich-Kister equation and the values of the parameter ai and standard deviation have been reported. The volumetric properties are fully consistent with viscometric and thermodynamic properties.A.K.M. Nasimul IslamMaster of Philosophy in Chemistr
