Brief Review of the Results

Estimation of influent biodegradable organic matter need to be determined to know the loading on the wastewater treatment plant. For this various parameters are estimated but the important parameter is ΔCOD. Estimation of ΔCOD takes approximately 20- 24 hours and attempt has been made to correlate the respirometric BOD + CODc with ΔCOD for seven samples of domestic wastewater. Respirometric BOD at I. S. O. U. R. = 0.1, 0.08 and 0.06 Vs ΔCOD correlate well with a coefficient of variation 6.3 %. Respirometric BOD + CODc at sag correlate poorly with ΔCOD. Results of these experiments indicate that initially a line of regression is to be determined between BOD or BOD+ CODc Vs ΔCOD. By knowing BOD or BOD+ CODc at the appropriate time, for which line of regression has been determined. ΔCOD can be estimated with reasonable accuracy within ten hours. If line of regression between BOD+ CODc at sag Vs ΔCOD is determined and then BOD+ CODc at sag is estimated for the unknown sample ΔCOD can be estimated within 1 to 5 hours.

Scientific and technological benefits emerging out

With the BOD estimation in the membrane respirometer, quick estimate of ΔCOD with reasonable accuracy may be obtained. With BOD estimation in the membrane respiromter and determination of total and filtrate COD an accurate estimation of ΔCOD may be obtained. Initially regression (BOD Vs ΔCOD or BOD+ CODc Vs ΔCOD) for 5 to 7 samples of a particular wastewater is to be determined. Afterwards by merely determining BOD in the membrane respirometer or and total and filtrate COD, ΔCOD for the wastewater may be estimated from the regression equation. The advantage of this procedure is that the accurate values of ΔCOD can be estimated with a reasonably shorter time in comparison to time required for estimating ΔCOD by conventional COD measurement procedure.

Manpower trained: 2 M.E. (Environmental Engineering) students trained

Brief Review of the Results Scientific and technological benefits emerging out

Development of two new materials (Zirconium antimonophosphate and Zirconium phosphotungustate), which have been characterized as ion-exchangers. These ion-exchangers possess excellent chemical and thermal stabilities. Exchange kinetic studies for alkaline earth metal ions indicate particle diffusion mechanism operating in the exchange process. Ion exchange process comprises of a sequence of steps and hence observed activation energy obtained by using Arrhenius plots (valid only for elementary processes) cannot be related to the total exchange process. Ion exchangers were characterized by using analytical techniques like XRD, IR, TGA, spectrophotometric studies. Distribution coefficients were determined for a number of metal ions on zirconium and the materials were found to be selective for Ba²⁺, Pb²⁺, Cu²⁺ and Fe²⁺ ions. An electrochemical study on the ion exchangers reveals that Zirconium phosphotungustate is selective for some metal ions and hence can be applied as an electroactive component in the preparation of Ion Selective Electrodes.

Scientific and technological benefits emerging out

Brief Review of the Results

Two Sm(III) Ion-selective electrodes were prepared using electroactive materials; zirconium boratophosphate and tin boratophosphate. Working concentration range of the electrodes was 1x10^-5 M to 1x10^-1 M for Sm(III) ions with a near Nernstian slope of 20.20 mV/decade and super-Nernstian slope of 40 mV/ decade respectively. The sensor showed good selectivity for Sm(III) with respect to alkali, alkaline earth, some transition and rare earth metal ions that are normally present along with samarium. Effect of partially non-aqueous media on the response of electrodes has been studied. The electrode has also been used as an indicator electrode in the potentiometric titration of Sm(III) ions against EDTA. Also electrodes for Ce(III) and Pr(III) were prepared using zirconium antimonoarsenate and zirconium (IV) antimonotungstate. These electrode worked well over a concentration range of 5x10^-5 M to 1x10^-1 M of Ce(III) ions and 5x10^-5 M to1x10^-1 M of Pr(III) ions, respectively. The proposed sensors showed good selectivity for cerium (III) with respect to alkali, alkaline earth, some transition and rare earth metal ions.

Cerium (III) selective membrane electrodes were prepared using various binding materials such as epoxy resin, PVC and polystyrene. Best performance was given by a membrane having composition ZrSbAs (50%) and polystyrene (50%). The electrode has also been used as an indicator electrode in the potentiometric titration of Ce(III) ions.

Pr(II) selective electrodes based on PVC and polystyrene as binders using zirconium (IV) antimonotungstate as an electro-active material have also been prepared. Electrode assembly was interfaced with Orion Analyzer (Model EA-940) using Lab view software from National Instruments, USA. These electrodes worked well over concentration range of 5x10^-5 M to 1x10^-1 M of Pr³⁺ ions with a near Nernstian slope of 25 mV/ decade.

Scientific and technological benefits emerging out:

The proposed sensors can be used as tools for quantitative determination of rare earth metal ions and can be applied to real life samples from nuclear power plants, automobile industry. The electrodes have a good commercial market as potentiometric sensors.

Two research papers published in international refereed journals. One research paper presented in international conference held at Tsukuba (Japan) on July 2004.

Manpower trained: One candidate completed the Ph.D. on similar topic.

Brief Review of the Results and Scientific & technological benefits emerging out

SPM concentration at 5 different sampling sites were measured and was high in Oct-Nov and April-May during 2006-2010, as these were the months when farmers carry out crop residue burning activities after rice and wheat crop harvesting, respectively. It can be concluded from the study that crop residue burning performed after rice and wheat harvesting during Oct - Nov and April - May, greatly affect the concentration of SPM, SO₂ and NO₂ in Patiala. Results show that SPM concentration at all the sites during this sampling period was above the NAAQS (200 mg m^-3) while the SO₂ and NO₂ concentration levels were below the limits (80 mg/m³) prescribed by the Central Pollution Control Board. Meteorological parameters were monitored from Aug’06 to Feb’10. Wind direction was NW during most of the monitoring period which greatly influenced the SPM levels in Patiala. Wind speed was not much fast. On the sampling days, which were just after rainfall, very low SPM concentration is obtained. The atmospheric pressure varied from 997 hPa -1005 hPa.

The respiratory parameters show significant decrease in its value during the CRB season. The values of FVC of lower age group in April’07 (3.86 L) are lower as compared to that of March’07 (4.11 L). Again, in Oct’07 (3.68 L), FVC is lower as compared to that in Sept’07 (4.06 L) and same in Oct’08 (3.68L) and Oct’09 (3.56 L) as comparison to value in Sept’08 (4.01 L) and Sept’09 (3.92 L). Similar trends were obtained in the case of medium and upper age group subjects. In the burning period, the ability of individuals to expire air forcefully (FVC), decreases and thereafter the FVC value increases as SPM level decreases. Same trend was observed in the case of FEV₁ and other respiratory parameters. FVC values for lower, middle and upper age groups decrease in April’07 (3.86 L, 3.59 L and 2.87 L) in comparison to March’07 (4.11 L, 3.81 L and 3.11 L). Again in the rice crop residue-burning season i.e. October 2007 (3.69L, 3.53L and 2.73 L) decrease in FVC was observed as compared to that in September 2007 (4.06 L, 3.74 L and 3.03 L) for all age groups. Almost same trends were seen in the year 2008-09. From these observations, it is clear that lower and upper age groups the variation is large as compared to the middle age group. It indicates that lower and upper age groups are more affected as compared to middle age group. Similar trends are observed for FEV₁, PEF, etc.

Brief Review of he Results and Scientific & technological benefits emerging out

Ion selective electrodes for five different metals have been prepared for many important transition metal ions such as cobalt, nickel, zinc, copper and silver using amide based ionophores. Commercialization of the proposed electrodes can be done for the quantitative determination of the respective metal ions in the real life samples. Also, the proposed electrodes have been applied as indicator electrodes in the potentiometric titrations (both direct and reverse) of the respective metal ion. Some of the electrodes prepared for silver metal ions have been applied for carrying out potentiometric titrations of halide ions and CN-,SCN- ions from mixture of theses ions excellent results are obtained. Detection limits have been lowered using different plasticizers, various lipophilic salts and selecting suitable ionophores but still more efforts can be made for getting the detection limits in the nanomolar to picomolar range. Also the miniaturization of the electrode assembly can be done so as to make the experimental setup more compact.

Brief Review of the Results and Scientific & technological benefits emerging out

Screened, identified and isolated microbes sensitive to Cu, Zn and Cd ions. Immobilization of the microbes was done by glutaraldehyde method. Characterization of the electrode with respect to immobilization, glutaraldehyde exposure, time of drying etc. was done to make the electrode workable as biosensor membrane composition and conditions of current measurement were optimized. The method was used for determination of Ultra trace analysis of heavy metal ions like zinc, cadmium, cobalt etc. upto concentration of 10^-12M with modified platinum electrode and 10^-14M for modified Glassy carbon electrode

Real life sample analysis from streams and other water sources. Sewage disposal of sea ships for various metal ions for heavy metal ions before disposing to sea and in-situ determination of heavy metal ions can be done.

Brief Review of the Results and Scientific & technological benefits emerging out

A new analytical method was established for the quantitative determination of lanthanides by a simple and rapid conductometric method. The results obtained in the form of changes in conductivity followed during complexometric titration against EDTA have been explained. The proposed method is based on the application of a co-ligand (HIBA) during complexometic titration with EDTA, which helps to achieve separate equivalence points that are otherwise not achievable with only EDTA. Necessary condition for determining lanthanides in the presence of each other for a binary mixture is that a co-ligand is required. The proposed method is tested for selective determination of individual lanthanides in the presence of interfering ions like selected alkali, alkaline earth, and transition metal ions. The method does not suffer from interference from any of these species.