Stabilization and dewatering of wastewater treatment plants sludge using the Fenton process

Wastewater sludge typically contains large amounts of water and organic materials; therefore, its stabilization and dewatering is of particular importance. In this study, Fenton oxidation process is used for stabilization and dewatering of sludge in the output of a wastewater treatment plant. To evaluate the sludge stabilization and dewatering, specific resistance to filtration (SRF), volatile organic compounds (VSS), total suspended solids (TSS), soluble chemical oxygen demand (SCOD) and heterotrophic bacteria were measured. During the experiment, the optimal values of various parameters such as pH (2-9), hydrogen peroxide (0.015- 0.18mol/L), Fe2+ (0.008- 0.1mol/L) and time (5 - 60 minutes) for optimum sludge dewatering and stabilization were investigated. The results showed that the highest percentages of SRF reduction and removal rates of SCOD, VSS and TSS were 99.48, 61, 42, and 41 percent respectively. These results were obtained in optimum pH 5, 0.05 mol/l Fe2+, 0.12 mol/l hydrogen peroxide, and the retention time of 15 minutes. The removal rate of heterotrophic bacteria increased with increasing dose of hydrogen peroxide, so that a removal rate of 84 percent was observed at a dose of 0.18 mol/l. In general, Fenton process can reduce volatile organic materials and chemical oxygen demand of the sludge resulting in its significant stabilization and dewatering. In general, Fenton process can reduce volatile organic materials and chemical oxygen demand of the sludge resulting in its significant stabilization and dewatering

Organophosphorous Pesticides in Surface Water of Iran

Abstract This research aims to evaluate the presence and distribution of pesticides in Babolrood River of Mazandaran Province in Iran. Mean diazinon levels in surface water ranged from 77.6 to 101.6 lg L-1 with maximum level of 768.9 lg L-1 and mean malathion levels ranged from 55.7 to 75.9 lg L-1 with maximum level of 506.6 lg L-1 . The residues of malathion and diazinon pesticides in all of the stations, 2 weeks after spraying, were more than allowed limits

A conventional PCR for differentiating common taeniid species of dogs based on in silico microsatellite analysis

Canine taeniids are among the major tapeworms with remarkable medical and economic significance. Reliable diagnosis and differentiation of dog taeniids using simple and sensitive tools are of paramount importance for establishing an efficient surveillance system. Microsatellites as abundant unique tandem repeats of short DNA motifs are useful genetic markers for molecular epidemiological studies. The purpose of the present study was to find a primer pair for rapid differentiation of major tapeworms of dogs, Taenia hydatigena, T. multiceps, T. ovis and Echinococcus granulosus, by screening existing nucleotide data. All the mitochondrial genome records as well as non-coding ITS1 sequences of Taeniidae species were downloaded from Nucleotide database from NCBI. For prediction and analysis of potential loci of STR/SSR in ITS1 as well as mitochondrial regions, we used ChloroMitoSSRDB 2.0 and GMATo v1.2. software. Different tapeworm species were categorized according to different motif sequences and type and size of each microsatellite locus. Three primer sets were designed and tested for differentiating taeniid species and evaluated in a conventional PCR system. Four taeniid species were successfully differentiated using a primer pair in a simple conventional PCR system. We predicted 2-19 and 1-4 microsatellite loci in ITS1 and mitochondrial genome, respectively. In ITS1, 41 Di and 21 Tri motifs were found in the taeniids while the majority of the motifs in the mitochondrial genome were Tetra (89) and Tri (70). It is documented that the number and diversity of microsatellite loci is higher in nuclear ITS1 region than mostly coding mitochondrial genome

Leaching Zn, Cd, Pb, and Cu from Wastewater Sludge Using Fenton Process

Background: High amount of heavy metals in sludge is one of the major obstacles to its use on farms. The present study aimed to investigate the possibility of leaching heavy metals from wastewater sludge by Fenton method and determine the optimum level of parameters, such as iron, hydrogen peroxide, time, and pH for Fenton reaction. Methods: The effects of various parameters, such as pH (2-9), hydrogen peroxide concentration (0.5-6 g/l), Fe concentration (0.5-4 g/l), and leaching time (5-60 min), were studied. Results: The results showed that the optimal condition for leaching of heavy metals occurred at pH of 2-3, hydrogen peroxide concentration of 3 g/l, iron concentration of 2 g/l, and leaching time of 15 min. Under these optimal conditions, 92% of Zn, 100% of Cd, 100% of Pb, and 80% of Cu were leached from the wastewater sludge. Conclusions: Fenton method can leach heavy metals from wastewater sludge through decomposition of organic materials at H2O2/Fe ratio of 1.5:2

Stabilization and Dewatering of Wastewater Treatment Plants Sludge Using the Fenton Process

Wastewater sludge typically contains large amounts of water and organic materials; therefore, its stabilization and dewatering is of particular importance. In this study, Fenton oxidation process is used for stabilization and dewatering of sludge in the output of a wastewater treatment plant. To evaluate the sludge stabilization and dewatering, specific resistance to filtration (SRF), volatile organic compounds (VSS), total suspended solids (TSS), soluble chemical oxygen demand (SCOD) and heterotrophic bacteria were measured. During the experiment, the optimal values of various parameters such as pH (2-9), hydrogen peroxide (0.015- 0.18mol/L), Fe2+ (0.008- 0.1mol/L) and time (5 - 60 minutes) for optimum sludge dewatering and stabilization were investigated. The results showed that the highest percentages of SRF reduction and removal rates of SCOD, VSS and TSS were 99.48, 61, 42, and 41 percent respectively. These results were obtained in optimum pH 5, 0.05 mol/l Fe2+, 0.12 mol/l hydrogen peroxide, and the retention time of 15 minutes. The removal rate of heterotrophic bacteria increased with increasing dose of hydrogen peroxide, so that a removal rate of 84 percent was observed at a dose of 0.18 mol/l. In general, Fenton process can reduce volatile organic materials and chemical oxygen demand of the sludge resulting in its significant stabilization and dewatering. In general, Fenton process can reduce volatile organic materials and chemical oxygen demand of the sludge resulting in its significant stabilization and dewatering

Data on the level of haloacetic acids in indoor swimming pools of Iran: A case study of Tehran

Haloacetic acids (HAAs) are the second most prevalent class of DBPs after trihalomethanes (THMs) in water disinfected by chlorine compounds. Within this study, we present new data on occurrence and speciation of HAA levels in 15 indoor swimming pools in Tehran in 2017. Five HAAs (HAA5), including monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid were analyzed. Levels of pH, total chlorine, and total organic carbon concentration were analyzed as well. Results indicated that the levels of HAA5 in swimming pools in the Tehran ranged from 148 to 3488 µg/L, with an average of 1045.26 µg/L. HAAs in the swimming pools in Tehran might be due to the extensive use of chlorine compounds for disinfection. Therefore, due to the high levels of HAAs, frequent monitoring of HAA levels as well as minimization strategies is needed in these swimming pools. Keywords: Haloacetic acids, Indoor swimming pools, Disinfection, Tehra

Focal hot spot induced by a central subclavian line on bone scan

The diagnostic accuracy of nuclear medicine reporting can be improved by awareness of these instrument-related artifacts. Both awareness and experience are also important when it comes to detecting and identifying normal (and abnormal) variants. We present a case of hot spot on the upper right chest in the region of right subclavicular region resulting from injection of radiotracer from central subclavian line. A 52-year-old woman with a history of left breast cancer and recent bone pain was referred to our nuclear medicine department for skeletal survey. Anterior views of chest show a focus of increased radiotracer uptake corresponding to anterior arch of one of the right second rib. The nuclear physician reported it as a focal rib bony lesion and recommended radiological evaluation. As technician later explained, physicians realized that injection site was a central subclavian line on the right side and hot spot on that region is due to injection site. The appearance of both skeletal and soft-tissue uptake depends heavily on imaging technique (such as the route of radiotracer administration) and the interpreting physicians should be aware of the impact of technical factors on image quality

Levels of formaldehyde in residential indoor air of Gonabad, Iran

Human health has been identified to be affected more significantly by indoor air quality. Among numerous pollutants present in indoor air, formaldehyde (FA) is of great concern because of its highly hazardous nature. The concentrations of FA were determined from 20 newly decorated homes in the city of Gonabad, Iran during 2015. It was found that the indoor air levels of FA in all the sampled houses were exceptionally high in the range of 21 to 360 µg/m3 (mean of 149.3 µg/m3). If the 24-h average concentrations of FA measured from those sites were concerned, nearly 40% of them were seen to exceed the WHO guideline values (i.e., 100 µg/m3). One of the important reasons for the high concentrations could be low air exchange rates in those houses (e.g., from 0.18 to 0.37 h−1), high levels of humidity in the newly decorating houses and stronger sources in the indoor environment. Furthermore, its pollution in homes with natural ventilation was seen to be much higher than those of mechanical ventilation. Due to high levels of indoor FA, more effective control procedures should be developed and employed to reduce the risk associated with formaldehyde exposure

A case report of prostate cancer with leptomeningeal metastasis

BACKGROUND: Prostate cancer is the most prevalent cancer in men. However, leptomeningeal involvement by prostate carcinoma is a rare event. CASE: Here, we report a 69‐year‐old patient with castration‐resistant metastatic prostate cancer who presented with headache and ataxia. Brain MRI revealed a huge invasive interaxial mass at right occipital lobe with diffuse thickening and enhancement of meninges, the arachnoid, and the pia mater, and he was diagnosed with leptomeningeal carcinomatosis. The patient received whole brain radiotherapy. CONCLUSION: Despite the fact that brain and leptomeningeal metastases are not very common in patients with prostate cancer, signs and symptoms of nervous system disorders should be assessed carefully, and consideration of such unusual metastases must be considered