BackgroundIn recent years the generation rate of construction and demolition waste (C&D) has significantly augmented. The aim of this study was to assessed the quality and quantity of construction and demolition waste in Tehran (capital of Iran).MethodsQuestionnaire methods were used for estimating the amount of generated C&D wastes national statistical data and typical waste generation data. In order to defining the composition of C&D waste, trucks were randomly selected and their wastes were separated and weighted.ResultsAccording to obtained results, about 82,646,051 m3 of C&D waste (average 16,529,210 m3 per year) were generated during 2011 to 2016 which only about 26% of them has been recycled. Mixing sand and cement, concrete, broken bricks and soil have the highest amount of the composition of C&D waste in Tehran that was 30, 19, 18 and 11%, respectively. Based on the results, about 2,784,158 t of the waste will generate in 2025 and this is approximately 122% higher than wastes generate in 2016. Based on MAPSA’s data, 360 teams of personnel cruise and control the illegal disposals, but due to the expansion of Tehran this number of teams is inadequate and can’t be effective in controlling the situation.ConclusionIn general, the overall condition of C&D waste management in Tehran seems undesirable and needs to be updated based on the experience of successful countries in this field.
BackgroundIn Iran, re-refinery industry has been developed many years ago based on the acid-clay treatment. Acidic sludge with high concentration of total petroleum hydrocarbon (TPH) is the final products of some facilities. In this study removal of TPH by aerated in-vessel composting was investigated.MethodsIn order to microorganisms seeding and nutrient providing, urban immature compost was added as an amendment to acidic sludge. The ratios of acidic sludge (AS) to compost were, 1:0 (as control), 1:5, 1:8, 1:10, 1:15, 1:20, 1:30, 1:40, 1:50, 1:75 and 1:100 (as dry basis) at a C: N: P ratio of 100:5:1 and 45–65% moisture content for 70 days.ResultsThe removal efficiency in all reactors was more than 48%. The highest and lowest TPH removal was observed in 1:5 (71.56%) and 1:100 (48.53%) mixing ratios, respectively. The results of the control reactors showed that biological treatment was the main mechanism for TPH removal. Experimental data was fitted second order kinetic model (R 2 > 0.8006). Degradation of TPH in 1:5 mixing ratio (k2 = 0.0038 gmg −1d−1; half-life = 3.08d) was nearly three times faster than 1:100 mixing ratio (k2 = 0.0238; half-life = 8.96d). The results of the control reactors showed that biological treatment was the main mechanism for TPH removal.ConclusionThe results of this study revealed in-vessel composting with immature urban compost as the amendment maybe recommended as an effective method for TPH remediation.
To determine aluminum and zinc in Iranian consumed tea, 31 tea samples were analysed for Al and Zn concentration of tea leaves and tea infusion. The results show that average concentration of Al and Zn in tea leaves was 326 and 50.7 mg. Kg(-1) respectively in this regard Nemoneh and Shahrzad show the highest and lowest concentration respectively in term of Al, also Debsh and Alkozi follow same situation in Zn concentration. Also the solubility of metals in the first infusion was significantly (Al, Zn: P < 0.01) higher than the second infusion and the solubility in the second infusion was also significantly higher than the third infusion (Al: P < 0.01; Zn: P < 0.05). Al leachate in the first infusion (2 min) for Mosama and Seilan tea was highest and lowest respectively. Also in the second and third infusion (5 and 10 min) Golkis and Nemoneh tea show the highest and lowest figures respectively. On the other hand, data from Zn transfer in tea infusion in the first infusion show that Mosama and Ahmad Atry tea have the highest and lowest leachate percentage respectively, while in the second and third infusion Mosama and Golkis tea follow the same situation. Calculation of percentage 'available' Al and Zn to the human system showed that 1 l of tea can provide 37.2% of the daily dietary intake of Al, the percentage 'available' for absorption in the intestine is only 1.78% for overall mean Al concentration. Also daily dietary intake of Zn was 2.13% while percentage available for absorption in the intestine was 0.72%.
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