BACKGROUND AND OBJECTIVES: Developing countries'' governments face challenges in municipal solid waste collection, such as rapidly increased volume of waste, physical and social obstacles to collection routes, or funding shortages. The lack of practical evaluation of the waste collection Performance is considered a gap in improving the waste collection system in these countries. This study aims to assess the efficiency of current municipal solid waste collection by analyzing Operational data that can help enhance the collection.METHODS: The geographical information system and the geographical position system data of all active trucks were collected for 14 consecutive days using the digital map. Data on waste volume collected by trucks, waste volume at collection points, and Operational time of trucks throughout a working day were collected by survey. The Operational efficiency indicators, including the deadhead rate, waste collected per distance unit, stopping time rate, and costs, are estimated to evaluate the effectiveness of municipal solid waste collection services.FINDINGS: The results indicate that solid waste collection efficiency of 1.67 tons/kilometers is low for high-density population areas. The deadheading rate of approximately 20 percent shows that the collection route operated by drivers is meandering and inefficient. Although using small trucks (6–7 tons) for transporting waste to landfills over a long distance is inefficient, small vehicles are used more than large ones. Ineffective utilization of transfer stations could lead to high idle time, accounting for approximately 37.6 percent of a collection trip. The regulated estimating method for transportation costs is not comprehensively developed, which may cause mistakes in choosing collection vehicles for operation and transfer station usage.CONCLUSION: The research findings assess the Performance and identify ineffective factors that require improvement of waste collection, aiming to enhance the solid waste management system. Waste collection routes of Hoan Kiem district must be designed using empirical data. The distance-based coefficients should be developed for all collection vehicles with different loading capacities to better estimate collection and transportation costs in Hanoi, helping decision-makers utilize the current transfer station more effectively and appropriately in choosing collection vehicles for operation.

Nitrogen compounds such as triethylamine are odorants generally found in chemical plants and foundries in which cold-box cores are made. In this study, the efficiency of biofiltration of triethylamine (TEA) vapor was evaluated. Experiments were conducted in two 6-L biofilters arranged in three stages and packed with inoculated compost - wood chips (40:60v/v) as the filter medium. The seed inoculum was obtained from municipal activated sludge. Tests were made to compare effects of initial temperature (30±1°C, biofilter A) and (23±2 °C, biofilter B) on the Performance of the biofilter. TEA elimination rate pattern was evaluated by changing loading rates (6-138 gm-3h-1 and hydraulic retention times (40-60 s) while operating at constant temperature and humidity at 50-55%. Results showed that organic loading rates (OLR) of up to 114.4 gm-3h-1 (biofilter A) and 90.56 gm-3h-1 (biofilter B) could be handled without any apparent indication of maximum elimination capacity and substrate inhibition. The elimination capacity of biofilters could reach up to 72 gm-3h-1 (biofilter A) and 61.5 gm-3h-1(biofilter B). When the loading of TEA exceeded the critical values, substrate inhibition occurred and the elimination capacity decreased. However, the requirement of keeping the pressure drop below 4 cm water gauge per meter of bed height to avoid Operational problems warranted lower than maximum capacity operation. The optimal OLR values of 90±14 gm-3h-1 are suggested for hydraulic retention time value of 48 s and temperature of 30±1°C. Under these conditions, elimination capacity of 71±3 gm-3h-1and removal efficiency of 81±14% was achie

Background: A hand-held portable direct-reading monitor, including photoionization detector (PID) is renowned for its good sensitivity, considerable dynamic range, and nondestructive vapor detection ability in comparison to the tardy response of the PID in gas chromatography (GC), which its application has been restricted. In this study, the Performance of a PID system (MultiRAE Lite) was evaluated as a replacement of GC in the measurement of toluene in a dynamic adsorption system. Methods: The test was done at different relative humidity levels (30%, 50%, and 80%), temperatures (21, 30, 40 ° C), and toluene concentrations (20, 100, 200, and 400 ppm). Results: The PID achieved 48% of all measurements meeting the comparison criterion. The results showed that the Performance of the PID could be altered by the variables. The best Performance of the PID was at temperature of 21 ° C, the relative humidity of 50%, and concentration of 200 ppm with the percentage of readings achieving the criterion of comparison to 58%, 54%, and 52%, respectively. The averages of the PID readings (mean ± SD at 200 ppm= 207. 9 ± 8. 7) were higher than the reference method measurements averages (mean ± SD at 200 ppm= 203. 5 ± 5. 8). The regression analysis of the toluene results from the PID and the reference method results indicated that the measurements were significantly correlated (r 2 = 0. 93). Conclusion: According to the results, the device response is linear. Therefore, the findings are acceptable in adsorption studies. In this way, the measurement of the sample concentration should be performed using the same instrument before and after the reactor in order to calculate the adsorption efficiency.