THE EFFECT OF ROTOR ROTATION SPEED ON DECREASED LABORATORY LIQUID WASTE POLLUTING PARAMETERS

<span id="docs-internal-guid-ee22e381-7fff-07aa-8160-5bce2ec61810"><span>aboratory wastewater is produced through laboratory activities. Laboratory wastewater can have a large impact on the environment if it is not processed before being discharged into the water body. Laboratory waste treatment can be carried out using suspended growth technology to reduce pollutant loads, especially Biological Oxygen Demand (BOD</span><span><span>5</span></span><span>) and Chemical Oxygen Demand (COD). </span><span>Aims:</span><span> This study aims to treat wastewater produced by the activity of laboratory using suspended growth technology. </span><span>Methodology and Results:</span><span> This research was conducted by finding the most efficient rotor rotation in degrading the load of BOD5 and COD pollutants. The reactor used is a Mixed Flow Reactor type reactor made of acrylic material with a thickness of 5.5 mm. The reactor is arranged into three series with the same sampling time and different rotor turns that expressed in rotors per minute (rpm). The reactor series consists of Reactor I with 50 rpm rotor rotation speed, 100 rpm Reactor II and 150 rpm Reactor III. Processing is carried out using 8 hours of detention time and variation of sampling time every 8 hours. </span><span>Conclusion, significant and impact study:</span><span> From the results of the study obtained the highest level of effectiveness of reducing pollutant load on processing using 150 rpm rotor rotation and 40 hours sampling time which is 94.6% for BOD</span><span><span>5 </span></span><span>parameters and 94.4% for COD parameters.</span></span>

Determination of kinetic coefficients for treating synthetic oily wastewater in suspended growth batch fed reactor

Discharge of oily wastewater imparts serious threat to the environment because of high level concentration of COD, BOD as well as oil and grease and it is difficult to treat such wastewater due to its inherent toxic and inhibitory property. A treatability study of oily wastewater (carrying petroleum) has been performed in the present work using a batch suspended growth reactor. The experiment was conducted using acclimatized suspended biomass in laboratory environment and the kinetic coefficients were determined which are immensely important for design of such reactor. The oil removal efficiency was observed to be in the range of 62.84–85.45% corresponding to average MLSS concentration range of 1,797–3,668 mg/L. Haldane kinetic model was found to be the best fitted for the biodegradation of oily wastewater with acclimatised microorganisms in the present investigation. The kinetic co-efficients including Ks, Y, kd, k and ki were calculated from the experimental data and the values were compared with published results cited by various scientists. The derived kinetic coefficients values are to be useful for understanding the dynamics of substrate utilisation with production of biomass and efficient design of biological systems and also for pilot plant investigation with real life wastewater of similar nature.

Use of microbial consortium along with biosurfactants in oil sludge treatment

Due to the excessive use of various oils, a large amount of oil sludge or waste water is produced annually which is causing various environmental and health issues. Bioremediation through the use of microbial consortium is an effective method. The use of consortium instead of single specie of bacteria has shown 89-94% improved results. However the microbes are still not able to work effectively due to bioavailability issues. This is mainly because of the low solubility of hydrophobic contaminants and microbes. This problem is overcome by use of biosurfactants which enhance the solubility and emulsification of hydrophobic substrates and microbes. These biosurfactants are produced by various organisms (mainly microbes) which are later isolated and used. Certain new and efficient insitu techniques are used for the application of microbial consortium which includes suspended growth, attached growth and hybrid growth. Waste water treated this way can be reused in the refinery procedures or can be dumped safely.

Adsorption and partitioning behaviour of selected trace polycyclic synthetic musks in a suspended growth aerobic activated sludge system

This thesis investigated the influence of sludge retention time (SRT) and temperature (T) on selected activated sludge properties and their influence on partitioning and sorption behaviour of selected trace polycyclic synthetic musks (PSMs) of environmental concern. Suspended growth aerobic activated sludge systems under controlled temperature (10 and 20°C) and SRTs (3.5 and 10.5 days) conditions fed by municipal sewage were investigated. The selected PSMs monitored included Cashmeran, Celestolide, Phantolide, Traseolide, Galaxolide and Tonalide. Activated sludge floc properties including relative hydrophobicity (RH) and extracellular polymeric substances (EPS) showed significant differences which correlated well (r [subscript p] of ± 0.4 to ± 0.7) to the removal and partitioning of PSMs removed from the aqueous phase and associated with activated sludege. Galaxolide and Tonalide were found to represent over 95% of the total PSMs in both the aqueous and solid phases. PSMs aqueous reduction from 62 to 80% was observed. The total PSMs associated with sludge ranged from 15 to 27 [micro]g/g d.m. and the lowest concentration was observed under 10.5 days SRT and 20°C which also resulted in nitrifying conditions. SRT was the dominant operational factor, followed by SRT and TxSRT in influencing the partitioning of the PSMs and floc properties. The Freundlich equilibrium PSMs sorption and desorption isotherms, for sludges were generated and showed significant differences in sorption behaviour.