Al2 (SO4)3, 18H2O, FeCl3 and Ca (OH)2 were used for the treatment of tannery wastewaters. The influences of pH and coagulant dosages were studied. Conditions were optimised according to the pollutant removal efficiencies, the volume of decanted sludge and the biodegradability index improvement. The results indicate that 67-71% of total COD, 76-92% of color and 79-97% of Cr can be removed using the optimum coagulant dosages at the optimum pH range. Al2 (SO4)3, 18H2O and Ca (OH)2 produced better results than FeCl3 in terms of COD, color and Cr removal as well as in terms of biodegradability improvement. Moreover, Al2 (SO4)3, 18H2O and FeCl3 produced the least amount of sludges for a given amounts of COD, color and Cr removed in comparison with Ca (OH)2. Al2 (SO4)3, 18H2O seems to be suitable for yielding high pollutant removals and corresponding low volumes of decanted sludges in addition to improving wastewaters biodegradability index.

This article is part of a research in which the possibility of preparing and formulation a biocomposite based on cellulose, polyethylene (PE) and polyethylene glycol (PEG) was studied. Therefore, the cellulose was blended with two kinds of PE, LDPE and HDPE in different formulations using internal blending machine at 125 and 145 oC, respectively. The biodegradability of the obtained composites was investigated via soil burial test. Thus in the certain periods, soil buried samples were taken out of the soil, removed of the soil and weighed. Analysis of the weight changes of the soil buried samples showed that their weight loss had a reducing trend, which means the biodegradability and disintegration had occurred in the samples. Therefore, the LDPE and HDPE- cellulose composites showed the significant biodegradability properties that depending on the aim of the composites applications, this property of samples may be desirable or undesirable.

Introduction: Several reports have indicated that chlorophenols are toxic chemicals and recalcitrant to biodegradation. Advanced oxidative processes (AOPs) are one of the most effective processes for degradation of persistent compounds. Since the mineralization of recalcitrant compounds by AOPs often requires long reaction time and strong dose of oxidant, combination of this process with biological one is considered as one efficient and economic method. Methods: In this work treatment of 2,4,6 TCP wastewater by Fenton's is oxidation in batch reactor and combination of Fenton reaction with activated sludge for removal of TCP in continues mode were studied. Results: Initial concentration of 2,4,6 TCP was 0.6 mM and in pH = 3, [H2O2] =1.8 mM [Fe2+] = 0.6 mM 99% of TCP was degraded in first minute after the reaction was started COD analysis indicated that TCP did not mineralize because COD reduction was only < 37%. Chloride ion increasing from 0 mg/L to 40mg/L, PH decreasing from 3 to 2.74 and UV215 absorbance decreasing from 3.2 to 0.6 indicated that generated intermediates toxicity reduced and biodegradability enhanced. Pilot study of Fenton's oxidation / activated sludge integration for treatment of 2,4,6 TCP wastewater showed that intermediates in effluent from Fenton reactor (operating at [H2O2] / [Fe2+] =3, [H2O2] / [TCP]=3, pH=3, reaction Time = 1hr [TCP]0 = 120 mg/L aqu COD @ 150 mg/L). Degraded by Activated sludge process and COD reduction were ~ 75%. Increasing of aeration Time from 6 hr to 18 hr has no significant effect on removal efficiency (p=0.005). Increasing of concentration of TCP has no significant effect on removal efficiency (p=0.005). Increasing of glucose into the aeration tank caused that COD removal efficiency increased from 75% to 92%. Conclusion: Results from this study indicated that Fenton’s oxidation process is an effective method for biodegradability Enhancement of 2,4,6 TCP and generated intermediates from Fenton’s oxidation of 2,4,6 TCP are easily Biodegradable compounds.

In the present study the mechanical and biodegradability properties of Low-Density Polyethylene (LDPE)/propolis blended films were investigated. For this purpose, crude propolis was powdered and was added to the polymer matrix at different percentages of propolis to LDPE (0, 5, 10, 15, and 20 by weight percentages). The films were prepared by the extrusion method. The characterizations of the obtained films were determined by using mechanical (tensile) and biodegradability in soil tests. The study of the microscopic structures of the films was performed using Field Emission Scanning Electron Microscopy (FESEM). FESEM images showed that the surface of the films containing propolis was swollen in the island form as compared to the control and this property expands with the increase in the amount of propolis in the polymer matrix. The mechanical properties of films showed that the addition of propolis to LDPE film reduced the tensile strength and also reduced the relative elongation of the films from 16. 5262 and 1%, respectively, for film control to 9. 7794 and 0. 840% for LDPE film containing 20% propolis. The biodegradability results of these films showed that after 150 days of film placement in the soil, the biodegradability process in the films containing propolis was more rapid than the control. The percentage of soil biodegradability in the film containing 20 percentages of propolis was the highest and reached 5. 2 percent. Also, the mechanical properties of the films after 150 days of soil biodegradability also decreased for each film containing propolis than before.

Polypropylene/starch nanocomposites compatibilized with PP- g -MA or EVA, with values 0, 3 and 5 wt% of modified clay (Cloisite 30B) were prepared by melt intercalation technique and the mechanical properties, morphology and degradation of nanocomposites were investigated. Tensile test results showed that in the presence of 5 wt% nanoclay, values of tensile strength, elastic modulus and elongation-at-break are 15.5 MPa, 10.2 MPa and 4.2% for PP- g -MA compatibilized blends and 10.0 MPa, 7.0 MPa and 19.4% for EVA compatibilized blends, respectively. Also, the presence of 5 wt% nanoclay increased 9.1 % of tensile strength; 70 % of elastic modulus and decreased 49% of elongation-at-break for PP- g -MA compatibilized blends and increased 40.8% of tensile strength, 27.3% of elastic modulus and 49% of elongation-at-break for EVA compatibilized blends. The reason for these properties improvement could be proper dispersion and physical network consisting of silicate layers in the polymer matrix. SAXS patterns and TEM images confirmed that the prepared nanocomposites were exfoliated. SEM microscopic images show droplet morphology that is indicative of incompatibility of two polymers. Oxidative degradation of samples exposed to UV light was studied using FTIR spectroscopy. The weight loss percentage of MA-5, EVA-3 and EVA-5 specimens after 120 days of exposure in activated sludge resulted in 20.7, 28.4 and 37.9%, respectively. These results indicate that biodegradation of EVA compatibilized blends is much higher with increasing nanoclay which has improved the biodegradablility of the blends.

Backgrounds and Objectives: Leachate is one of the landfill products and also a wastewaterbearing the most advers effects on the environment. Biological methods are usually employed fortreatment of young leachate (1-2 years) wich is of high concentration of organic compounds withlow molecular weight. However these methods are not approprate for mature leachate (5-10years) due to having high rate of compounds with molecular weight and the presence of materials resistant to biodegradation and toxic compounds. Advanced oxidation process such as Fenton reagent used in treatment or biodegrability improvement of strong wastewater. In the present study the degrabilityimprovement of mature leachate through oxidation fenton process in bench scale and in batch reactor has been investigated.Materials and Methods: The samples have been taken from Ahwaz landfill and factors such as initial COD and BOD, pH, BOD5/COD were studies as degradability, the amount of Hydrogen Peroxide, Fe(II), optimal reaction time and optimal pH.Results: The highest amount of COD removal was observed in PH=3-3.5 and 90 minutes of reaction time. H2O2=29700mg/land Fe2+=16500 mg/l in [Fe2+]/[H2O2]=1/14.8 molarity ratio were obtained as optimal amounts BOD5/COD was equal to 0.38.Conclusion: This study indicates that Fenton oxidation enhances the biodegradability of leachate.