| The problems posed by fecal sludge(FS)are multidimensional because most cities rapidly urbanize,which results in the increase in population,urban settlement,and waste generation.Issues concerning health and waste treatment have continued to create alarming situations.These issues had indeed interfered with the proper steps in managing FS,which contaminates the environment.FS can be used in agriculture as fertilizer because it is an excellent source of nutrients.However,human feces are considerably liable to spread microorganisms to other persons.Thus,sanitation should be the main objectives of FS treatment to minimize the risk to public and environmental health.The sanitization effect of lactic acid fermentation(LAF),compost-dewatering,and pyrolysis processes were conducted to evaluate the efficiency of the treatment technologies for the production of hygienic biochar for soil amendment.First,lactobacillus inoculum,fermented cassava flour and fermented rice flour were mixed at equal ratio with raw FS(i.e 1:1)in three different reactors.Results show that only fermented rice flour inactivated fecal coliform at the end of the fermentation process,within the period of 21days.Final plate counts of 8.6×108 CFU/100mL,2.4×108CFU/100mL and zero(0)were achieved from lactobacillus inoculum,fermented cassava flour and fermented rice flour treatment processes respectively.In the second approach,a combination of fermented rice flour and brown sugar was used as the medium to prepare LAB.The pH of FS decreased during ongoing LAF after the addition of the LAB suspension.Results revealed that fecal coliforms in reactor 1:1 and 2:1 w/w of FS and LAB suspension decreased to half of the initial concentration within seven days,in comparison with that of the control reactor.Viable plate counts of 0.9×108,0.6×108,and 2.4×108 CFU/00 mL were recorded from reactors 1:1,2:1,and the control,respectively.The total elimination of fecal coliforms below the detection limit(<3 log 10 CFU/100mL)was observed in both reactors after 15-17 days,whereas the number of fecal coliforms remained at 2.3 × 108 CFU/100 mL in the control reactor.Compost-dewatering and pyrolysis were conducted on the fermented FS.Dewatering process lasted for a period of 35 d.Results showed that MC decreased in the three reactors amended with 10%biochar and dry leaves,except the control reactor.Final MC of 35.1%,37.3%,38.9%and 65%was observed in reactor 1:1,2:1,3:1 and control respectively on day 35.During pyrolysis process,pH values from samples produced under the temperature condition of 450? were higher than those of 350?.However,pH values of all the biochars produced were alkaline.This biochar can be used to improve the pH of acidic soils.Fecal matter biochar offers an important value propotion where pyrolysis process guarantees 100%pathogen destruction.Survey results showed that most respondent supports fecal sludge management towards resource recovery.Amongst them,54% are satisfied with the recent sanitation approach,78%supports FSM option,72%supports the application of sanitized FS for soil amendment,while 62%respondents are comfortable with the physical appearance of biochar recovered from the sanitized FS.It could be concluded that provision of productive sanitation system where waste could be used as nutrient resource in rural and urban centers will be of economic advantage and will lead to sanitation and sustainable development. |
PDF Full Text Request