ABSTRACT
Background and Aims: aromatic hydrocarbons are the common pollutants used in many industries. Among the aromatic compounds, aniline has a widespread application in the chemical industry. Regarding its dangerous effects on human and the environment health, there are severe limitation on water containing aniline. This study aimed to remove aniline from aqueous solution using the activated carbon produced from cotton stalks
Materials and Methods: all aniline absorption tests were done on activated carbon produced in batch reactors and containing 50 ml Erlenmeyer flask with a volume of 100 ml and concentrating on aniline and absorbent regarding different parameters including pH [2-4-6-8-10 ], adsorbent dose [0.02-0.04- 0.06 and 0.08 mg / l], the dose of absorbing [50- 100-150V 200 mg / l], exposure duration of [5 15-30- 40-50-and 60 minutes] temperature [10-20-40 and 50 degree C]
Results: according to the results the optimum values obtained were, 60 minutes with 82.05% efficiency, a dose of 0.06 mg / l with efficiency of 90%, the concentration of 50 mg / l with an efficiency of 75.64%, pH 6 with an efficiency of 67.71% as. Also, studies on carbon isotherm follows the Langmuir isotherm [R2> 0.9989] and synthetic quadratic equation
Conclusion: according to the results of this study and considering the absorption capacity of carbon, it can be accepted and suggested as a suitable, cheap and local alternative for Merck Carbon Standard, to treat water and wastewater pollutants
ABSTRACT
Background: This study assessed the removal of organic material and nutrients from full-scale subsurface flow [SSF] constructed wetlands [CWs] followed by anaerobic stabilization ponds under environmental conditions
Methods: The effluents were distributed evenly in 12 reed beds. Samples were taken twice monthly for a total of 6 months from several points in the wetland. Biochemical oxygen demand [BOD], chemical oxygen demand [COD], total suspended solids [TSS], and nutrient removal from the system and the longitudinal effect of the reed beds for removal of pollutions were determined. A full-scale model of flow, BOD, and nutrients in SSF in the CWs is presented
Results: The flow rate and concentrations of parameters indicated that removal of organic matter and nutrients in the cold months decreased rather than in the hot months, as expected. The removal efficiency for BOD, COD, and TSS and the strongest biological interactions showed no uniform trends. The beds showed the highest removal rates in the first few meters of bed. The hybrid Monod-Plug flow regime and the Stover-Kincannon models showed the best fit for the kinetics of the processes. U[max] in the Stover-Kincannon model was 3.64 mg/l.d for nitrogen and 0.24 mg/l.d for phosphorus. These values are very low, which indicates lower consumption and inefficiency of the system for removing nitrogen and phosphorus
Conclusion: It can be concluded that the SSF in CWs are able to treat average wastewater as effectively as common mechanical systems at lower cost
ABSTRACT
Background: In recent years, crisis of water shortage has become a serious problem in many countries. In this regard, the use of treated wastewater in natural or artificial method in agriculture and the like, has been proposed as an important and practical solution. The natural purification method by the use of artificial canebrakes, compared with other methods of treatment is an appropriate method because of its low cost, and also, because of easy navigation, the requirements of low technology and low energy consumption. Several herbs have been used to increase the efficiency canebrakes which including special plants to purify such wastewater is Vetiveria that has unique genetic, morphological and physiological characteristics. Due to the limited knowledge of the plant's industrial wastewater treatment, in this study, a comparison of filterablity of hospital wastewater was done between Vetivaria and bulrush in tropical areas.
Methods: This experimental study was done in 2013 in the hot season, summer. In this study, was made two pilot glass with dimensions of 50*60*100 Cm. A mixture of soil, sand, gravel, clay soil was selected. The irrigation method in this study was subsurface and continuous. First, hospital wastewater via a 220 liter tank as the primary sedimentation retention time and with time of 2 hours entered into bed with a hydraulic retention time of 4 days to discharge 85/0 liters per hour. To evaluate the efficiency of each plant in the treatment of hospital wastewater, chemical parameters including [PH, TP, TN, TSS, BOD5, COD]were measured according to standard methods of measuring. . Analysis of the data was done by the use of t-test and Mann-Whitney and SPSS software.
Results: Based on the finding of this study, percentage of removal parameter[Bod5, Tss, Tn, Tp] by plant Vetiveria was [88.54, 95.71, 93.93, 99.80] and for bulrush was [82.54, 91.13, 86.64, 99.28].
Conclusion: Due to the unique characteristics of Vetiveria, such as high resistance against unfavorable environmental conditions and its higher efficiency than bulrush, this plant is recommended for the treatment of hospital wastewater.