Heavy metals pollution has become a more serious environmental problem in the last several decades as a result releasing toxic materials into the environment. Various techniques such as physical, chemical, biological, advanced oxidation and electrochemical processes were used for the treatment of domestic, industrial and agricultural effluents. The commonly used conventional biological treatments processes are not only time consuming but also need large operational area. Accordingly, it seems that these methods are not cost-effective for effluent containing toxic elements. Advanced oxidation techniques result in high treatment cost and are generally used to obtain high purity grade water. The chemical coagulation technique is slow and generates large amount of sludge. Electrocoagulation is an electrochemical technique with many applications. This process has recently attracted attention as a potential technique for treating industrial wastewater due to its versatility and environmental compatibility. This process has been applied for the treatment of many kinds of wastewater such as landfill leachate, restaurant, carwash, slaughterhouse, textile, laundry, tannery, petroleum refinery wastewater and for removal of bacteria, arsenic, fluoride, pesticides and heavy metals from aqueous environments. The objective of the present manuscript is to review the potential of electrocoagulation process for the treatment of domestic, industrial and agricultural effluents, especially removal of heavy metals from aqueous environments. About 100 published studies (1977–2016) are reviewed in this paper. It is evident from the literature survey articles that electrocoagulation are the most frequently studied for the treatment of heavy metal wastewater.

Background/Aims: There are no studies of the phonatory parameters of elderly Iranian speakers. The purpose of this study was to obtain normative acoustic data for a group of elderly Iranian male and female speakers over 70 years of age. Four selected acoustic parameters [fundamental frequency (F0), jitter, shimmer, and harmonics-to-noise ratio] were obtained and compared to a group of young and middle-aged speakers. Methods: Subjects were 21 Iranian elderly men and 20 Iranian elderly women. The age range for both male (mean ± SD: 77.09 ± 5.84) and female subjects (77.55 ± 4.34) was 70–90 years. The control group consisted of 40 Iranian young and middle-aged adults who were 20–49 years old (20 men and 20 women). The age range for the females was 23–40 years (30 ± 4.76) and for the males it was 21–49 years (30.1 ± 8.51). Each subject phonated 5/a/vowels with constant pitch and loudness for at least 5 s. The mid 3-second portion of the tokens was analyzed using the Dr. Speech 4.3u software (subprogram: Vocal Assessment; Dr. Speech, Tiger Electronics, Seattle, Wash., USA). Results: F0 was greater for elderly males than for young and middle-aged males. Conversely, F0 was greater for young and middle-aged females than for elderly females. Average shimmer was significantly higher in elderly males than in elderly females. Likewise, jitter was significantly higher in elderly males than in elderly females. Both shimmer and jitter were significantly greater in elderly speakers than in the young and middle-aged speakers. In addition, the harmonics-to-noise ratio was significantly greater for young and middle-aged males and females than for elderly males and females. Conclusions: The results of this study indicate that elderly Iranian speakers had significantly greater vocal instability than young and middle-aged Iranian adults, as measured by the selected acoustic parameters. As the elderly population in Iran and the world continues to increase rapidly, studies of this kind are needed for researchers, educators, and practitioners to better understand the effects of aging on all aspects of human speech-language communication. Voice is an important factor for communication, and its change with age alters the communication process.

Background. Obesity has become a significant public health issue worldwide, and it is a major risk factor for many noncommunicable diseases. This systematic review aimed to identify the prevalence of obesity and overweight in the Middle East region and different countries in this region. Materials and Methods. PubMed, Google Scholar, and MEDLINE databases were searched from 2000–2020 to identify relevant studies in the Middle East area. The survey was carried out using combinations of Medical Subject Headings (Mesh) keywords like “body mass index”, “obesity”, “overweight”, “prevalence”, “Middle-East”, and “Countries in the Middle East area”. Analysis of the data was done using STATA-14, and a random-effects model was used to estimate the pooled prevalence. Results. A total of 101 studies with 698905 participants have been identified that met inclusion criteria for this meta-analysis. The pooled estimates of the prevalence of obesity and overweight in the Middle East area were 21.17 (95% CI: 17.05–26.29) and 33.14 (95% CI: 26.87–40.87), respectively. The findings showed that obesity prevalence increased with age so that the highest prevalence of obesity and overweight was observed in people >40 years old. Obesity prevalence in the Middle East area remained steady between 2000–2006 and 2014–2020 (23%). During these time intervals, the prevalence of overweight decreased from 34.83 (95% CI: 32.40–37.45) to 32.85 (95% CI: 31.39–34.38). Conclusions. Despite the relative stabilization of the overweight and obesity trend in the Middle East, current interventions to combat the overweight epidemic need to be maintained and strengthened because the prevalence of overweight and obesity in this region is still very high. The prevalence of obesity increases with age so that people over 40 have the highest percentage of obesity and overweight. Therefore, implementing intervention programs to prevent and control obesity and overweight in the Middle East is essential.

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