EVALUATION THE PROPERTIES OF PURIFIED LACCASE EXTRACTED FROM SOME LOCAL PLANTS UNDER THE OPTIMUM CONDITIONS

This study set out to screen 36 common plants which have the greatest level of laccase enzyme activity. It revealed that the enzymatic activity of fenugreek seeds was the highest in comparison with other plants. The optimal enzyme-specific activity was 5340.38 units per milligram protein which were obtained by extracting the enzyme with a sodium phosphate buffer at a concentration of 0.02 M and pH 8.0, at a ratio of 1:40 (weight to volume), and extracting time of 210 minutes. The enzyme yield was 27.6% after extraction and purification by gel filtration using Sephacryl S-3 after 1.01 purification fold. The optimum circumstances for enzymatic activity and stability were found by using 0.1 M sodium acetate as a buffer at pH 5. Also, the maximal activity and stability of purified laccase was obtained at 20 oC for 15 min by using o-tolidine as a substrate. This research sheds light on how to isolate and characterize the laccase enzyme, an important biochemical with numerous biotechnological and technological uses through fenugreek seeds as a source of the laccase

A SUSTAINABLE RAW RICE HUSK ADSORBENT FOR EFFECTIVE LEVOFLOXACIN REMOVAL FROM AQUEOUS SOLUTION: KINETIC, THERMODYNAMIC AND ISOTHERM STUDIES

Levofloxacin (LEV) is an important and widely used antibiotic. It is used to treat many bacterial infections. It may be found in water sources as a result of incomplete metabolism in humans and other sources. In this study, the adsorption of Levofloxacin by raw rice husk (RRH) was investigated. The effect of pH, time, temperature, RRH weight, and initial Levofloxacin concentration on the adsorption process were determined. Kinetic, isotherm and thermodynamic models were studied to explain the Levofloxacin adsorption mechanism on raw rice husk. The results of adsorption kinetics and isotherms revealed that the adsorption of LEV by RRH was better fitted with the Intraparticle model with coefficient of determination (R2=96%), while the Langmuir model represents the best isotherm model to describe the adsorption process with (R2 =95%).  The removal efficiency reached 99% , the monolayer maximum uptake qmax is 2.47 mg/g and the  adsorption intensity parameter (1/n) value is 0.763, which means that the adsorption is favorable. According to the thermodynamic coefficients, the adsorption process was spontaneous and feasible for the temperatures under investigation; the sorption efficiency was more favorable at higher temperatures, and the adsorption process is endothermic

Treatment of Dairy Wastewater by Electrocoagulation using Iron Filings Electrodes

This study investigated the treatment of dairy wastewater using the electrocoagulation method with iron filings as electrodes. The study dealt with real samples collected from local factory for dairy products in Baghdad. The Response Surface Methodology (RSM) was used to optimize five experimental variables at six levels for each variable, for estimating chemical oxygen demand (COD) removal efficiency. These variables were the distance between electrodes, detention time, dosage of NaCl as electrolyte, initial COD concentration, and current density. RSM was investigated the direct and complex interaction effects between parameters to estimate the optimum values. The respective optimum value was 1 cm for the distance between electrodes, (60 – 120) min for detention time, 250 mg NaCl/L added, C0/6 = 5,775 mg COD/L as initial COD concentration, and  7.884 - 8.077  mA/cm2 as current provided. At the optimum parameter values, the optimum COD removal efficiency was 73.4%. Meanwhile, the study also performed removal efficiency for nitrogen (N) and phosphate (P) due to their effects on the aquatic life and systems. The optimum removal efficiency for phosphorus and nitrogen was 98.0% and 80.3%, respectively. Due to its effects on the environment and to comply with local legislations, treating these wastewaters using eco-friendly processes was highly recommended taking in consideration the economic feasibility, flexibility and easiness to operate. In addition, the study proved that the high surface area for iron filings played a crucial role in removing process

DETERMINATION OF THE OPTIMUM CONDITIONS FOR UREASE EXTRACTED FROM SOME LOCAL PLANTS

In the current study, Seventeen types of plants commonly used namely (Chickpeas, Tomato, Soybean, Mustard, Baker, Lebbeck, Bean, Sesame, Male Iraqi berries, Female Iraqi berries, Indian berries, Potato, Radish, Legumes, peas, Watermelon, and Phaseolus were obtained and screened for urease activity, among these plants, Sesame was chosen with maximum enzymatic activity, and it had the highest productivity of urease enzyme (1.623 U/mg protein). The optimum extraction ratio represented by 1:10 (W: V) after 90 minutes and 0.8414U/mg protein. Sodium phosphate buffer (0.1 M, pH 7.0) was chosen as the best extraction buffer with specific activity 0.9004U/mg protein

Subsurface Flow Phytoremediation Using Barley Plants for Water Recovery from Kerosene-Contaminated Water: Effect of Kerosene Concentration and Removal Kinetics

A phytoremediation experiment was carried out with kerosene as a model for total petroleum hydrocarbons. A constructed wetland of barley was exposed to kerosene pollutants at varying concentrations (1, 2, and 3% v/v) in a subsurface flow (SSF) system. After a period of 42 days of exposure, it was found that the average ability to eliminate kerosene ranged from 56.5% to 61.2%, with the highest removal obtained at a kerosene concentration of 1% v/v. The analysis of kerosene at varying initial concentrations allowed the kinetics of kerosene to be fitted with the Grau model, which was closer than that with the zero order, first order, or second order kinetic models. The experimental study showed that the barley plant designed in a subsurface flow phytoremediation system would have great potential for the reclamation of kerosene-contaminated water

Optimization Kerosene Bio-degradation by a Local Soil Bacterium Isolate Klebsiella pneumoniae Sp. pneumonia

Isolated Bacteria from the roots of barley were studied; two stages of processes Isolated and screening were applied in order to find the best bacteria to remove kerosene from soil. The active bacteria are isolated for kerosene degradation process. It has been found that Klebsiella pneumoniae sp. have the highest kerosene degradation which is 88.5%. The optimum conditions of kerosene degradation by Klebsiella pneumonia sp. are pH5, 48hr incubation period, 35°C temperature and 10000ppm the best kerosene concentration. The results 10000ppm showed that the maximum kerosene degradation can reach 99.58% after 48 h of incubation. Higher Kerosene degradation which was 99.83% was obtained at pH5. Kerosene degradation was found to be maximum at 35°C with 98.63%, where 10000ppm kerosene showed the highest degradation at 99.527%. The results indicate that the isolated Klebsiella pneumonia sp. is extremely efficient in degrading kerosene hydrocarbons

Heavy Metals Removal from Simulated Wastewater using Horizontal Subsurface Constructed Wetland

This study aimed to assess the efficiency of Nerium oleander in removing three different metals (Cd, Cu, and Ni) from simulated wastewater using horizontal subsurface flow constructed wetland (HSSF-CW) system. The HSSF-CW pilot scale was operated at two hydraulic retention times (HRTs) of 4 and 7 days, filled with a substrate layer of sand and gravel. The results indicated that the HSSF-CW had high removal efficiency of Cd and Cu. A higher HRT (7 days) resulted in greater removal efficiency reaching up to (99.3% Cd, 99.5% Cu, 86.3% Ni) compared to 4 days. The substrate played a significant role in removal of metals due to adsorption and precipitation. The N. oleander plant also showed a good tolerance to the uptake of Cd, Cu, and Ni ions from water. The highest removal of the heavy metals indicated that the HSSF-CW would be a promising technology for heavy metal contaminated wastewater as well as in electroplating and manufacturing industries

Biodegradation of reactive dyes by some bacteria using response surface methodology as an optimization technique

Water pollution as a result of contamination with dye-contaminating effluents is a severe issue for water reservoirs, which instigated the study of biodegradation of Reactive Red 195 and Reactive Blue dyes by E. coli and Bacillus sp. The effects of occupation time, solution pH, initial dyes concentrations, biomass loading, and temperature were investigated via batch-system experiments by using the Design of Experiment (DOE) for 2 levels and 5 factors response surface methodology (RSM). The operational conditions used for these factors were optimized using quadratic techniques by reducing the number of experiments. The results revealed that the two types of bacteria had a powerful effect on biodegradable dyes. The regression analysis revealed a good match of the experimental data to the second-order polynomial with a high coefficient of determination (R2). The optimum conditions achieved by E. coli were temperature (39.9 °C), initial concentration (99.6 mg L−1), biomass loading (14.9 VBiomass/VSolution), incubation time (1 day), pH (7.23), while the optimum conditions achieved by Bacillus sp. were temperature (28.3 °C), initial concentration (98 mg L−1), biomass loading (5.8 VBiomass/VSolution), incubation time (1 day), and pH (7.9) obtained from the desirability function

Subsurface Flow Phytoremediation Using Barley Plants for Water Recovery from Kerosene-Contaminated Water: Effect of Kerosene Concentration and Removal Kinetics

A phytoremediation experiment was carried out with kerosene as a model for total petroleum hydrocarbons. A constructed wetland of barley was exposed to kerosene pollutants at varying concentrations (1, 2, and 3% v/v) in a subsurface flow (SSF) system. After a period of 42 days of exposure, it was found that the average ability to eliminate kerosene ranged from 56.5% to 61.2%, with the highest removal obtained at a kerosene concentration of 1% v/v. The analysis of kerosene at varying initial concentrations allowed the kinetics of kerosene to be fitted with the Grau model, which was closer than that with the zero order, first order, or second order kinetic models. The experimental study showed that the barley plant designed in a subsurface flow phytoremediation system would have great potential for the reclamation of kerosene-contaminated water