Assessment and modelling of residual chlorine in water supply systems: The case of Dangila Town, Ethiopia

Application of chlorine for drinking water security in the water supply distribution network for the Dangila town is not well managed. The study was conducted by the help of Water CAD software to evaluate the chlorine dosing and residual chlorine model. The necessary data were taken from primary and secondary sources. Three scenarios were developed for modelling the residual chlorine content in the distribution system. Two scenarios were produced with chlorine dose of 0.6 mg/l at a flow rate of 26 ml/s and chlorine dose of 0.5 mg /l at a flow rate of 22 ml/s, respectively. Residual chlorine concentration above normal limits (0.5 mg/l) was recorded in both scenarios around the injection point whereas four sample points were below 0.2 mg/l. Scenario II, all residual chlorine values were lower than 0.5 mg/l but still lower than 0.2 mg/l at the farthest four sampling points. In order to solve the above problem, A third scenario was developed with three reservoir injection points, Junction 4 and 55'' within 0.45, 0.15 and 0.2 mg/l of chlorine in order to maintain appropriate residual chlorine concentration. Hence, the best solution identified from the analysis was the installation of two additional chlorine injection points.

Prevalence and Associated Factors of Suicide Ideation and Attempt among Adolescent High School Students in Dangila Town, Northwest Ethiopia

Background. Suicide is a major public health problem and is common among adolescents worldwide. The true extent of the problem in Ethiopia is difficult to ascertain as suicides and suicidal behavior are significantly underreported and understudied. Objective. We assessed the prevalence and factors associated with suicide ideation and suicide attempt among adolescent high school students in Dangila Town, Ethiopia. Methods. This school-based cross-sectional study was conducted from April to May 2015 in Dangila Town. Data were collected from adolescent high school students using pretested, self-administered Amharic-language questionnaire. We conducted bivariable and multivariable logistic regression to identify the independent factors associated with suicide ideation and attempt. Results. A total of 573 of 603 sampled students participated in the study (95% response rate). The mean (±SD) age of the respondents was 17.52 (±0.97) years. The minimum and maximum ages were 15 and 19 years, respectively. The prevalence of suicide ideation and attempt was 22.5% and 16.2%, respectively. School absenteeism [AOR 4.30, 95% CI (2.03, 9.10)] and poor social support [AOR 5.58, 95% CI (2.25, 13.84)] were positively associated with suicide ideation. Poor social support [AOR 4.55, 95% CI (1.40, 14.77)] and being physically hurt [AOR 4.25, 95% CI (1.77, 10.20)] were positively associated with suicide attempt. Unlike previous studies of adolescents in low-income countries, we find no association between gender or alcohol use and suicidal thoughts or attempts. Conclusion. This study revealed that at least one in five of the adolescents in our sample had experienced suicide ideation and one in six had attempted suicide. School absenteeism, poor social support, and experience of violence were identified as independent contributors to suicide ideation and attempt. These findings suggest a need for education policymakers to implement school-based behavioral therapy programs in collaboration with health institutions and programs to provide social support for vulnerable students.