Evaluation of rapid purification of high concentrations of 2, 4-Dinitrophenol in wastewater using catalytic ozonation with carboneus nanocomposite

Background and purpose: 2, 4-dinitrophenol (DNP) are carcinogenic and non-biodegradable pollutants that exist at high concentration in wastewater of chemical industries. In this study, treatment and removal of organic materials (COD) in wastewater was carried out by catalytic ozonation process (COP) using carbon Nano-composite catalysts. Materials and methods: This study was conducted in cylindrical 250 mL semi-continuous reactor and the effects of several parameters including pH of the solution (4-10), the amount of catalyst concentrations (0 to 4 g/L), reaction time (0 to 60 min), and saturated catalyst was studied on treatment of high concentration of DNP and the COD removal efficiency. Also, the kinetics were compared with single ozonation (SOP). Results: Removal efficiency of high concentrations of DNP (1500 mg/L) and kinetics of the COP process catalyst concentration of 4 g/L was 83 (0.0241 min-1) while the results in SOP were 50 (0.0108 min-1). The optimum pH was 6 with the reaction time of 60 min. However, the removal efficiency of COD at initial concentration of 610 mg/L in the SOP process was 61 which increased to 92 after addition of the catalyst. The main mechanism of process was chemical oxidation and a small share (3) was due to adsorption. Conclusion: The results showed that COP and this new catalyst effectively and quickly removed high concentrations of DNP and COD. This method is believed to be economic due to the short time of ozonation, recovery and reuse of the catalyst. © 2016, AMazandaran University of Medical Sciences. All rights reserved

Impact of wastewater discharge on water quality of Karoon River in Iran

Preservation of the Karoon and Dez Rivers, the fresh water resource, is of high importance in Khuzestan province with its rapid growth of population and agricultural and industrial activities. In this paper the water quality and quality conditions of four study areas are mapped, agricultural, industrial and urban pollutant sources identified, and their impact on biological, physical and chemical water quality of Karoon River examined. Twenty five quality monitoring stations were established to determine the pollution load to the Karoon and Dez Rivers. The analysis shows that wastewater discharge has different impacts on chemical and biological water quality in the four study areas, in both the short and long term. © 2010 WIT Press

Wastewater project development of Tehran

Tehran, the capital city of Iran, has had many problems in the environmental field. Wastewater collection and treatment is one of most important of those. Tehran Sewerage Company has worked on the integrated wastewater management of Tehran by considering rapid population growth which results in increased water consumption and consequently more wastewater production. The wastewater project of Tehran began in 1959, but was stopped by the revolution in 1979. It was started again with financial support from the World Bank in 1990. This study conducted an environmental, social and financial assessment (short, medium and long term) of the Tehran Sewerage Project. Results showed that this project has moderate and temporary effects on environment and social communities. Furthermore, this paper proposes a management plan for mitigation measures (environmental monitoring and auditing). The combination of three solutions-governmental financial resources, public-private participation and the World Bank loan-as a function of three main factors-time, resources and quality-is discussed and investigated from an economic point of view. In this respect, supporting the private sector participation is considered as one of the critical factors for the success of the project. © 2010 WIT Press

Performance, kinetic, and biodegradation pathway evaluation of anaerobic fixed film fixed bed reactor in removing phthalic acid esters from wastewater

Emerging and hazardous environmental pollutants like phthalic acid esters (PAEs) are one of the recent concerns worldwide. PAEs are considered to have diverse endocrine disrupting effects on human health. Industrial wastewater has been reported as an important environment with high concentrations of PAEs. In the present study, four short-chain PAEs including diallyl phthalate (DAP), diethyl phthalate (DEP), dimethyl phthalate (DMP), and phthalic acid (PA) were selected as a substrate for anaerobic fixed film fixed bed reactor (AnFFFBR). The process performances of AnFFFBR, and also its kinetic behavior, were evaluated to find the best eco-friendly phthalate from the biodegradability point of view. According to the results and kinetic coefficients, removing and mineralizing of DMP occurred at a higher rate than other phthalates. In optimum conditions 92.5, 84.41, and 80.39% of DMP, COD, and TOC were removed. DAP was found as the most bio-refractory phthalate. The second-order (Grau) model was selected as the best model for describing phthalates removal

Study of Andimeshk's drinking water resources in Iran

This study was conducted to evaluate the application of different indices for the quality evaluation of eight groundwater resources of Andimeshk city on three months. Six corrosion indices of Langelier saturation index, Ryznar (saturation) index, calcium carbonate precipitation potential, Puckorius scaling index, Aggressiveness index and Larson-Skold corrosive index, were determined. Most of these resources had a high amounts of sulfate and affected the Laurence corrosion index, however were not exceeded the WHO standards. In the view of Larson-Skold corrosive index these water resources are corrosive for water facilities affected by chloride and sulphate, such as mild steel facilities. This index caused different results among other indices. From other indices, Ryznar (saturation) index and Puckorius scaling index indices showed different results among other indices and while other indices defined some resources as a non-corrosive, Ryznar (saturation) index and Puckorius scaling index predicted as a corrosive. In just one of the water resources, all the six indices had same results (moderately corrosive). Application of one index may not be able to predict water corrosivity, some factors such as water quality and water installation material should be regarded too. Some of those resources had high amounts of nitrate and phosphate which were contaminated by agricultural and domestic wastewaters

Prediction of gas emission and derived electrical power generation from Shiraz landfill

Landfilling has been considered as the most common method for solid waste disposal in developing countries which is faced with several issues, such as gas emission. Methane as a greenhouse gas is the main landfill gas which could be applied as a fuel for electrical power plants. In this study, the gas emission of Shiraz landfill site was predicted by using USEPA model, for this purpose, after determination of the solid waste physical composition on Shiraz landfill site, the L0 and k constants were estimated by Monte Carlo method, as well as the rate of gas collection and the rate of electrical power generation capacity were estimated under existing and ideal scenarios. The results showed that gas production would reach its peak up to 5.7�107 m3 year-1 by 2039. The maximum electrical power generation was also similar to the pattern of gas production in the landfill and would be 2545GWh and 4019GWh for the existing and ideal conditions, respectively in 2039. Results showed that the recovery of biogas at Shiraz landfill could be a desirable alternative in different available waste management options for this city. © 2015 Global NEST Printed in Greece. All rights reserved

Evaluation of photocatalytic degradation of 2,4-Dinitrophenol from synthetic wastewater using Fe3O4@SiO2@TiO2/rGO magnetic nanoparticles

Dinitrophenols (DNP), as a priority pollutant, is present in the effluents of several industries and also attracts the environmentalists' attentions, due to its harmful effects on human health. Several research have been conducted for 2,4-DNP degradation using advanced oxidation process (AOP). This study aimed to evaluate the degradation of 2,4-DNP by Fe3O4@SiO2@TiO2/rGO photocatalyst. FESEM, EDS, XRD, FTIR and VSM techniques were done to determine the characteristics of synthesized catalyst. Different variables such as pH of solution, initial concentrations of 2,4-DNP and photocatalyst dosages were studied to measure the degradation of 2,4-DNP. Also, the effect of interfering ions (e.g., Cl�, SO4 2�, CO3 2�) were investigated. Mineralization of pollutant in optimum conditions was also determined by TOC analysis. Finally, the reusability of magnetic photocatalyst was deliberated. In optimum experimental conditions (pH = 7, 2,4-DNP = 40 mg/L, photocatalyst dosage = 0.2 g/L), maximum 2,4-DNP removal was obtained 88.84 in 30 min reaction time with TOC removal of 50.04. Interfering ions reduced 2,4-DNP degradation in order of CO3 2� < Cl� < SO4 2�. Photocatalyst recovering (4 round) caused reduction of removal efficiency within 16.58. Photocatalytic degradation of 2,4-DNP followed pseudo first kinetic order. It could be concluded that the synthesized photocatalyst was a proper choice for degradation of 2,4-DNP by photocatalytic AOP process, based on good performance and high reusability. © 201

UV-Lamp Intensity Determination Without Use of Radiometer

Background and Objectives: Measurement of light intensity is a recommended practice for insuring the delivery of required germicidal dose in disinfection operations by UV lamps. Use of sensitive to light chemicals which is the base of actionometeric methods could be considered as a suitable manner for estimating the intensity of UV lamp in circumstances that special radiometers are not available."nMaterials and Methods: lodide-iodate mixture was used as an actinometer for this study. The light intensities of a UV lamp (LP 25W) were first determined by a special UVC ‌radiometer at certain distances from the lamp. Then the test of determining the suitable period of time for irradiation of actinometer was accomplished.  Finally، the color changes of iodide - iodate solutions at the predetermined distances were evaluated at the wavelength of 352 nm. The latter analysis can be done by a common (visible) spectrophotometer."nResults:‌ Results indicated that use of this actinometer is more suitable at the distances of 35 to 60 cm from the center of the lamp bulb، since iodode-iodate solution has a detectable color change at this range of distance in one minute irradiation which may be considered as a reasonable time for actionmeteric operations."nConclusion:  Although all kinds of actinometers should not be regarded as precise as special radiometers and there would be need to use pure chemicals for actinometeric determination of light intensity، it can be claimed that the recommended procedure in this study which is the newest actinometeric method can be used in acceptable evaluation of UV intensity with least difficulty in providing necessary instruments

Peroxymonosulfate catalyzed by core/shell magnetic ZnO photocatalyst towards malathion degradation: Enhancing synergy, catalytic performance and mechanism

In the current investigation, the ZnO nanoparticles were anchored on SiO2@Fe3O4 (S@F) core/shell surfaces to prepare ZnO-SiO2@Fe3O4 (ZS@F) nanocomposite. Characterization techniques confirmed the successful synthesis of ZS@F magnetic core/shells. The photocatalytic activity of pure ZnO was enhanced after its integration with SiO2@Fe3O4. The catalyst in coupling with UV-C light and peroxymonosulfate (PMS) showed a good performance towards malathion (MTN) degradation. Under optimal operational parameters (pH: 7, ZS@F: 0.3 g/L, PMS: 2 mM), 79.3 and 62.4% of MTN (20 mg/L) and TOC were eliminated within 60 min, respectively. The positive-charged holes and HO� radicals were the main reactive species during degradation reaction. The stability of ZS@F was investigated and revealed approximately 18% decrease in MTN degradation efficiency after 5 concecutive cycles. Finally, ZS@F/PMS/UV system can be used as a promising oxidation process for efficient degradation of MTN, because of its high catalytic performance, high stability, easy recovery and co-generation of various oxidative agents. © 2021 Elsevier B.V