| Abstract | This study investigates the relationship between field observation data and FS characteristics, the optimum polymer dosage, the influence of FS characteristics on polymer dosage and the optimum rotating mesh screen operational conditions. The main goal of this study is to optimize polymer dosage and operational conditions of rotating mesh screen and apply these optimum conditions on sanitizer truck.
The FS field observation data and FS characteristics were collected from vacuum truck from Nonthaburi Municipality. The field observation data was collected household member, onsite sanitation technology and emptying period from interview household owner. Moreover, FS was characterizing pH, conductivity, total solids, total suspended solids, total volatile solids, chemical oxygen demand, and ammonia. In addition, polymer dosage was optimized by jar-test experiment and optimum dosage was evaluated by capillary suction time test and suspended solids in liquid fraction. Furthermore, the rotational speed and solids loading rate were optimized by solid capture and solids concentration in thickened sludge.
The relationship between field observation data and faecal sludge characteristics was found that faecal sludge characteristics do not depend neither onsite sanitation types nor emptying period but it might be resulted from household member. For the optimum polymer dose result, faecal sludge with 0-1 percent total suspended solids is 40 mL/L of faecal sludge, faecal sludge with 1-2 percent total suspended solids is 60 mL/L of faecal sludge and faecal sludge with 2-4 percent total suspended solids is 80 mL/L of faecal sludge. The influence of faecal sludge characteristics on polymer dosage result, it was observed that total suspended solids, total volatile solids, total solids and chemical oxygen demand have medium correlation. Lastly, the optimum rotational speed is 2 rpm and solids loading rate is 3.2 kg/m2∙min.
Finally, this research proved that the household member has resulted on faecal sludge characteristics so it could be used to estimate polymer dosage because total suspended solids, total volatile solids, and chemical oxygen demand have medium correlation on polymer dosage. Furthermore, the optimum polymer dosage, the optimum rotational speed and solids loading rate of rotating mesh screen could be applied on sanitizer truck.
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