In exploring the application of natural coagulants in industrial wastewater treatment, plant-based coagulants have been gaining more interests due to their potential such as biodegradability and easy availability. Hylocereus undatus foliage as a plant-based coagulant has been proven to be efficient during the coagulation-flocculation process; however, limited research has been reported focusing only on palm oil mill effluent (POME) and latex concentrate wastewater. In addition, no previous study has been carried out to determine the performance evaluation of Hylocereus undatus foliage in treating different types of wastewater incorporating different operating conditions using optimization techniques. Hence, this study employed response surface methodology (RSM) in an attempt to determine the performance evaluation of the coagulant in paint wastewater treatment. Four independent factors such as the pH value, coagulant dosage, rapid mixing speed and temperature were chosen as the operating conditions. Three water parameters such as turbidity, chemical oxygen demand (COD) and suspended solids (SS) were chosen as responses in this study. Results revealed that through central composite design (CCD) via Design Expert software, the optimum conditions were achieved at pH 5, coagulant dosage of 300 mg/L, rapid mixing speed of 120 rpm and temperature at 30 °C. The experimental data was observed to be close to the model predictions with the optimum turbidity, COD and SS removal efficiencies found to be at 62.81%, 59.57% and 57.23%, respectively.
Background: Small cigarette pack sizes contain less than 20 cigarette sticks in a pack. Smaller packs may suggest lower costs, increasing affordability among lower-income users, especially the younger generation, which could lead to tobacco-related diseases and economic costs, including human capital lost results from tobacco-attributable morbidity and mortality. This concern has caused many countries to ban the sale of single cigarette sticks or kiddie packs. However, small cigarette pack sizes were proposed recently to be reintroduced by the tobacco industry with an excuse to prevent consumers from buying illicit cigarettes. This would demean efforts in combating tobacco consumption based on the existing tobacco control policies to prevent minors from purchasing cigarettes. Given the competing influences of affordability and availability of tobacco on consumption and the dearth of evidence-based review on the impact of pack size on smoking, this systematic review was conducted to identify the link between kiddie packs and smoking specifically on the initiation of smoking, urge/tendency to buy cigarettes among the general population and attempt to reduce cigarette consumption and prevalence of smoking using kiddie packs among current smokers. Methods: We include all studies except for reviews, guidelines, conference papers, commentaries, editorials, or opinion pieces. A database search was conducted in PubMed, EMBASE, CENTRAL, Web of Science and Scopus on 27 November 2021. The results were presented in the form of narrative synthesis under four groups: initiation of smoking; urge/tendency to buy cigarettes; the prevalence of smoking, and attempt to reduce cigarette consumption. The literature search identified 1601 articles, of which 21 articles had met the inclusion criteria. The methodological quality of all included articles was determined using a validated 16-item quality assessment tool (QATSDD). The average quality score for all papers was 34.8%. Discussion: Given the diverse study settings of the articles and despite the challenges of the methodological quality of some articles, this review provides some evidence that kiddie packs may increase the urge/tendency to buy cigarettes and mixed evidence on the attempt to reduce cigarette consumption. This review also found some evidence that kiddie pack purchasing among teenage smokers was higher compared to adults. However, we are uncertain about the link between kiddie packs and smoking initiation. Nevertheless, since most studies were of low quality, further high-quality studies are needed to conclude about the impact of kiddie packs on smoking to assist the policymakers and stakeholders in formulating new policies and strengthening existing strategies related to the kiddie packs.