Livestock slaughterhouses waste management in urban environment

The current study presents an investigation on the waste management in the cattle slaughterhouse by the following objectives: a) to identify the existing waste management practices in relation to sources, quantity and characteristic of wastes; b) to identify the situation of production, collection, storage, transportation, processing and recycling, and final disposal of wastes and the problems of existing waste management practices. In order to obtain reliable information and filling the check list, site surveys were conducted when the management of the slaughter-house was interviewed in waste management practices. The total produced industrial waste in studying units' was found to be 10252 tons/year. The per capita waste generations were reported to be 54.6 kg/cattle/day and 11.1 kg/sheep/day. Also, more than 98% of the hazardous waste produced can be infectious. However, it is important to keep in mind that setting an operational program and careful monitoring of its optimal execution by the slaughterhouse manager is necessary. Consequently, findings provide useful inputs for decision making processes around construction slaughterhouses waste management.  </strong

Design optimization of ocean renewable energy converter using a combined Bi-level metaheuristic approach

In recent years, there has been an increasing interest in renewable energies in view of the fact that fossil fuels are the leading cause of catastrophic environmental consequences. Ocean wave energy is a renewable energy source that is particularly prevalent in coastal areas. Since many countries have tremendous potential to extract this type of energy, a number of researchers have sought to determine certain effective factors on wave converters’ performance, with a primary emphasis on ambient factors. In this study, we used metaheuristic optimization methods to investigate the effects of geometric factors on the performance of an Oscillating Surge Wave Energy Converter (OSWEC), in addition to the effects of hydrodynamic parameters. To do so, we used CATIA software to model different geometries which were then inserted into a numerical model developed in Flow3D software. A Ribed-surface design of the converter's flap is also introduced in this study to maximize wave-converter interaction. Besides, a Bi-level Hill Climbing Multi-Verse Optimization (HCMVO) method was also developed for this application. The results showed that the converter performs better with greater wave heights, flap freeboard heights, and shorter wave periods. Additionally, the added ribs led to more wave-converter interaction and better performance, while the distance between the flap and flume bed negatively impacted the performance. Finally, tracking the changes in the five-dimensional objective function revealed the optimum value for each parameter in all scenarios. This is achieved by the newly developed optimization algorithm, which is much faster than other existing cutting-edge metaheuristic approaches

Simultaneous removal of chemical oxygen demand (COD) and ammonium from landfill leachate using anaerobic digesters

BACKGROUND AND OBJECTIVE: Leachate, which contains large amounts of ammonium and hazardous organic compounds, can lead to the pollution of surface water and groundwater; consequently, leachate collection and treatment are essential before discharge into the environment. Anaerobic digestion is one of the most cost-effective methods of contaminated wastewater treatment. In this study, we aimed to evaluate the efficiency of an anaerobic digester in simultaneous removal of chemical oxygen demand (COD) and ammonium from landfill leachate. METHODS: In this experimental study, a cylindrical anaerobic digester, made of Plexiglas sheets (with an inner diameter of 240 mm and useful volume of 10 L), was loaded with landfill leachate in Ghaemshahr, Iran. The effects of temperature (ambient temperature, 35°C, and 55°C) and various hydraulic retention times (1-5 days) on anaerobic digestion efficiency in COD and ammonium removal were assessed. FINDINGS: At a hydraulic retention time of five days, maximum COD and ammonium removal (94 and 36, respectively) was reported at thermophilic and ambient temperatures, respectively. The increase in hydraulic retention time had a positive impact on the efficiency of the digester in removing organic compounds and ammonium. Moreover, the rise in anaerobic digester temperature improved COD and ammonium removal. CONCLUSION: According to our findings, the developed anaerobic digester could be used as a convenient and efficient tool for removing organic matters from landfill leachate. However, given the low efficiency of this digester in ammonium removal, an additional aerobic stage is required for wastewater treatment. © 2015, Babol University of Medical Sciences. All rights reserved

Chromium removal from aqueous solution by a PEI-silica nanocomposite

It is essential and important to determine the adsorption mechanism as well as removal efficiency when using an adsorption technique to remove toxic heavy metals from wastewater. In this research, the removal efficiency and mechanism of chromium removal by a silica-based nanoparticle were investigated. A PEI-silica nanoparticle was synthesized by a one-pot technique and exhibited uniformly well-dispersed PEI polymers in silica particles. The adsorption capacity of chromium ions was determined by a batch adsorption test, with the PEI-silica nanoparticle having a value of 183.7 mg/g and monolayer sorption. Adsorption of chromium ions was affected by the solution pH and altered the nanoparticle surface chemically. First principles calculations of the adsorption energies for the relevant adsorption configurations and XPS peaks of Cr and N showed that Cr(VI), [HCrO4](-) is reduced to two species, Cr(III), CrOH2+ and Cr3+, by an amine group and that Cr(III) and Cr(VI) ions are adsorbed on different functional groups, oxidized N and NH3+

Determination of Tehran air quality with emphasis on air quality index (AQI); 2008-2009

Background and aimsIn recent years, because of excessive population growth, increasing of vehicles and developing of the industries, Tehran has been encountered with seriousenvironmental crisis, such as air pollution. So, for setting the control programs, air pollution monitoring and determination of Tehran air quality are necessaryMethodsIn the present study, Tehran air quality index (AQI) was calculated based on the five criteria pollutants levels (O levels in 1387 and with regarding to the national air quality standards for each pollutant categorized as good, moderate, unhealthy for sensitive groups, unhealthy and very unhealthy.Results The results of this research showed that in 2008-2009, with attention to United State environmental protection agency standards, in 43 days, air quality index was calculated lower than 100 and in the other 323 days, air quality index was higher than 100, that unhealthy for sensitive groups, very unhealthy and unhealthy was 40%, 27% and 21%, respectively. Also, in the summer, ozone and in the winter, carbon monoxide was determined as the pollutant responsible for the highest index value that is called the ''critical'' pollutant. The most polluted months with the average index of 204 and 214 were occurred in Tir (22 June to22 July) and Mordad (23 July to 22 August), respectively.Conclusioncomparison of the results of this study with others can be found that Tehran air quality did not improved and is in the very serious situation with regarding to public health, especially for sensitive groups. 3, PM10, SO2, NO2 and CO) through linear interpolation based on thes

Investigation of Cyanide Removal from Aqueous Solution Using Precipitation Process (FeCl3)

Background and Objectives: Cyanide is a toxic pollutant that is can be discharged from different industries such as iron and steel industry, coal mining and metal plating. Presence of this toxin in water and wastewater is a serious hazard and lead to undesirable effects on both the environment and human. Thus, its concentration control is essential for human health. The aim of this study was investigation of Cyanide Removal from aqueous solution using precipitation process (FeCl3). Material and Methods: This study is an experimental study in lab scale that was carried out in a batch system by jartest. Variations of this study including pH, FeCl3 concentration, reaction time and desired concentration of cyanide were investigated. Data were analyzed using Excel (version 2007) software. Results: The results of this research were showed that Cyanide with initial concentration of 10 mg/l in precipitation process was removed by 40% (conditions pH=90, FeCl3=0.4 g/l and the time 60 minutes). Also, the precipitation process efficiency to cyanide removal decreased of 40 to 23%, by increasing of the initial cyanide concentration of 10 to 15 mg/l. Conclusion: Precipitation process can be considered as a suitable alternative for recovery of cyanide to be re-used. Although, this process has limitations for treat total cyanide to environmental standards level. So, it is better be used in combination with other processes of these contaminants removal

An investigation on hospital solid waste management in Iran

The integrated hospital solid waste management emphasizes the need to conduct a survey based on a standardized method that equally be analyzed at national level. This study aimed to test the usability of a national tool to do integration data analysis of hospital waste management status. Then, a typical study was conducted in Karaj hospitals. Also, critical analysis of hospital�s solid waste management aspects was done, and shortcomings in the aspects were identified. The pilot study results showed that the daily per capita waste generations were reported to be 4.2±0.49 kg/available bed, 5.8±0.63 kg/occupied bed, and 10.3±0.9 kg/inpatient. The names of the hospitals were omitted when they were named from H1 to H8. So the highest and lowest daily waste generation rate were 5.5±0.35 and 2.6±0.78 kg/available bed in H7 and H3 hospitals, respectively. In this study, total infectious wastes per capita were reported to be 2.3±0.39 kg/available bed/day, 3±0.5 kg/occupied bed/day and 5.2±0.84 kg/inpatient/day. Furthermore, the averages per capita of total general waste were 2±0.4 kg/available bed/day, 2.8±0.51 kg/occupied bed/day and 5.1±0.8 kg/inpatient/day. Analysis of the Karaj hospital waste management status showed statue of hospital waste management in 88 of hospitals were ranked moderate when others were achieved to be poor by 12. The hospital waste management had been evaluated poor in term of collection, transportation and manpower aspects, moderate in the separation and temporary storage aspects and good in the disposal aspect. It was also found that the MOHME tool is appropriate tool to investigate the status of waste management in hospitals. © 2015 Global NEST Printed in Greece. All rights reserved

The Evaluation of Fenton Process Efficiency to Remove Phenol from Synthetic Wastewater

Introduction: Phenol is one of the aromatic hydrocarbons that exist in wastewater of various industries such as manufacturing chemicals, oil refinery and petrochemical industries. Because of its high toxicity and undesirable effect on organisms, its concentration control is essential in nature. The main objective of this study was to evaluate the efficiency of the Fenton oxidation process for the removal of phenol from synthetic wastewater. Methods: This is an experimental study.At the laboratory scale and in a batch system, the effect of pH, the optimal values of Fe 2+ and H2O2, exposure time and different concentrations of phenol on the removal efficiency of phenol was studied. In the samples, Phenol was measured by high-performance liquid chromatograph equipped with UV-Visible detector. Results: The results indicated that phenol with initial concentration of1.6 mM/Lin optimal conditions of pH =3, Fe2+=0.09 mM/L and H2O2=5.9mM/L (Fe2+/ H2O2= 0.015) was removed about 97% after 15 minutes. Increasing initial concentrations of phenol from1.6to3.7 mM / L caused a decrease in removal efficiency from 97 to 75%. The optimum ratio of Fe2+/ H2O2/Phenol was 0. 01. Conclusion: This method can be used as a suitable alternative option for the removal of phenol to meet environmental standards

Characterization and evaluation of treatability of wastewater generated in khuzestan livestock slaughterhouses and assessing of their wastewater treatment systems

Slaughterhouse wastewaters are characterized by a high organic content, mainly composed of proteins and fats. Therefore, these wastewaters should be treated efficiently prior to discharge into receiving bodies to avoid severe environmental pollution. This work aimed to characterize slaughterhouse wastewater generated in one province of Iran (Khuzestan), evaluating various suitability of biological treatment, assessing wastewater treatment plants performance and feasibility of wastewater reuse. Composite samples were collected from input and output of wastewater treatment plant during 6 months (spring and summer) and were analyzed for TSS, turbidity, temperature, conductivity, pH, COD, BOD5, fat, total coliform and fecal coliform. Data analysis was done using Excel and SPSS software. The results showed that different quantities of wastewater were generated in any slaughterhouses of Ahvaz (120-600 l/sheep/day), Dezful (110-550 l/sheep/day) and Shushtar (139-694 l/sheep/day). Khuzestan slaughterhouses wastewater is classified by pollution severity as strong wastewater. The BOD5/COD ranges from 0.3 to 0.5, which indicates applicability of biological treatment. Wastewater treatment plant of Ahvaz with anaerobic stabilization ponds and extended aeration activated sludge process has the highest removal efficiencies of pollutants. The result also indicated reuse of slaughterhouses effluent was not acceptable due to not comply with the standards of Iran. Finally, if safe use or disposal of these effluents is desired, blood capture from raw wastewater for reducing the amounts of organic loading must be implemented. Also, use of an appropriate treatment plant is noted. © 2016 Global NEST Printed in Greece. All rights reserved

Simultaneous Removal of Chemical Oxygen Demand (COD) and Ammonium ‎from Landfill Leachate Using Anaerobic Digesters

BACKGROUND AND OBJECTIVE: Leachate, which contains large amounts of ammonium and hazardous organic compounds, can lead to the pollution of surface water and groundwater consequently, leachate collection and treatment are essential before discharge into the environment. Anaerobic digestion is one of the most cost-effective methods of contaminated wastewater treatment. In this study, we aimed to evaluate the efficiency of an anaerobic digester in simultaneous removal of chemical oxygen demand (COD) and ammonium from landfill leachate. METHODS: In this experimental study, a cylindrical anaerobic digester, made of Plexiglas sheets (with an inner diameter of 240 mm and useful volume of 10 L), was loaded with landfill leachate in Ghaemshahr, Iran. The effects of temperature (ambient temperature, 35&deg;C, and 55&deg;C) and various hydraulic retention times (1-5 days) on anaerobic digestion efficiency in COD and ammonium removal were assessed. FINDINGS: At a hydraulic retention time of five days, maximum COD and ammonium removal (94% and 36%, respectively) was reported at thermophilic and ambient temperatures, respectively. The increase in hydraulic retention time had a positive impact on the efficiency of the digester in removing organic compounds and ammonium. Moreover, the rise in anaerobic digester temperature improved COD and ammonium removal. CONCLUSION: According to our findings, the developed anaerobic digester could be used as a convenient and efficient tool for removing organic matters from landfill leachate. However, given the low efficiency of this digester in ammonium removal, an additional aerobic stage is required for wastewater treatment