Iranian Journal of

Backgrounds  and Objectives:  Over than 70% of solid wastes is consisted of food wastes with high putrecibility in Iran.  Due to this regard, construction of composting factories for sanitary disposal or fertilizer production from solid wastes was very appreciated in our country. The objective of this research was to study on the quality and comparing of the compost produced by Khomain and Tehran compost factories.
Materials and Methods: This study was accomplished on the compost produce from Khomain and Tehran compost factories about 9 months. For investigation of chemical qualities of these materials, some indexes such as percentage of organic materials, carbon, nitrogen, phosphorus, potash and heavy metals consists of lead, cadmium, mercury and chromium were measured. Microbial quality of these compost materials were defined by assessing of the amounts of coliforms bacteria, salmonella bacteria and parasites ova.
Results: The average amounts of some indexes in compost of Khomain and Tehran were been: organic materials % (37.77, 29.80), carbon %( 22.14, 18.12), nitrogen% (2.08, 1.6), lead (229.6, 59.44 ppm), and chromium (70.2, 19.75), respectively. The microbial quality of these compost samples were agreement with class B of USEPA guidelines.
Conclusion: This study showed that quality of organic materials percent in Tehran's samples was better than Khomain's samples, but these indexes on these samples were lower than the grade No.2 of compost. The percentage of carbon, nitrogen and potash in these samples were desirable but, phosphorus amount were not in sufficient. The heavy metals especially lead and chromium in Tehran's samples were higher than Khomain's samples, but these samples were usually in agreement with guidelines of compost. Due to the defined microbial qualities, these samples could be used as well as amendment agents for poor soil.

Background and Objectives: Discharge of textile colored wastewater industries without providing enough treatment in water bodies, is harmful for human and aquatic organisms and poses serious damages to the environment. Most of conventional wastewater treatment methods don't have enough efficiency to remove textile dyes from colored wastewater thus in this research the efficiency of electrocoagulation treatment process with aluminum electrodes for treatment of a synthetic wastewater containing C.I. Reactive Red 198 in batch reactor was studied.
Material and Methods: The experiment conducted in a Plexiglas reactor with a working volume of 2L that equipped with 4 aluminum electrodes. The effects of operating parameters such as voltage, time of reaction, initial dye concentration and interelectrode distance on the color removal efficiency, electrical energy consumption and electrode consumption were investigated.
Results: in the optimum operational condition electrocoagulation, is able to remove color and COD as high as 99.1 and 84.3% in aluminum electrode in 75 minutes at 20 volt and 2 cm interelectrode distance, respectively. Under this condition, operating cost was 2986 rails per cubic meter of treated wastewater. Increase in the interelectrode distance and initial dye concentration,lead to the decrease in efficiency of dye and COD removal.While as the voltage and time of reaction increased, energy consumption, electrode consumption, final pH and color removal, increased too.
Conclusion: electrocoagulation process by aluminum electrode is an efficient and suitable method for reactive dye removal from colored wastewater.