Preparation of artificial MSW leachate for treatment studies: Testing on black soldier fly larvae process

When approaching the study of new processes for leachate treatment, each influencing variable should be kept under control to better comprehend the treatment process. However, leachate quality is difficult to control as it varies dramatically from one landfill to another, and in line with landfill ageing. To overcome this problem, the present study investigated the option of preparing a reliable artificial leachate in terms of quality consistency and representativeness in simulating the composition of real municipal solid waste (MSW) leachate, in view of further investigate the recent treatment process using black soldier fly (BSF) larvae. Two recipes were used to simulate a real leachate (RL): one including chemical ingredients alone (artificial synthetic leachate-SL), and the other including chemicals mixed with artificial food waste (FW) eluate (artificial mixed leachate-ML). Research data were analysed, elaborated and discussed to assess simulation performance according to a series of parameters, such as Analytical representativeness, Treatment representativeness (in this case specific for the BSF larvae process), Recipe relevance, Repeatability and Flexibility in selectively modifying individual quality parameters. The best leachate simulation performance was achieved by the synthetic leachate, with concentration values generally ranging between 97% and 118% of the RL values. When feeding larvae with both RL and SL, similar mortality values and growth performance were observed.

Effect of leachate recirculation and bulking agent on leachate quality

The purpose of leachate processing is to reduce pollutants in leachate without using equipment that requires high investment and complicated maintenance. This research aims to determine the impact of leachate recirculation and bulking agents on leachate quality. Fresh solid waste recirculated using artificial leachate with a continuous flow of 1 L/h. The study is conducting for 14 days on a laboratory scale. On the 14th day, combination recirculation and bulking accelerate the increased pH value. Leachate recirculation increases the potential for contact between methanogenic bacteria and dissolved organic matter and contributes to buffering pH during the hydrolysis process. R3 produces a higher Electric Conductivity (EC) value than other reactors since the 7th day. This increase is probably due to the addition of dissolved salts from solid waste decomposition. The role of the bulking agent may not be too significant for changes in the EC value. On day 14, TDS at R1 was 11,748 mg/L, R2 was 12.144 mg/L, and R3 was 14.916 mg/L.

Stabilization of paper waste in bioreactor landfills using soybean peroxidase enzyme

One obvious way to reduce the amount of paper waste being discarded, and to conserve the forest resources, is to recycle more of the waste paper. But most common waste management technique for solid waste is the use of landfills. This study was aimed at decomposing the waste in aerobic condition before the anaerobic condition using soybean peroxidase enzyme (SBP). One bioreactor cell without enzyme was compared with two bioreactor cells, which contained different concentration of soybean peroxidase enzyme with hydrogen peroxide (H₂O₂). The rate of reaction was analyzed by performing COD, BOD₅, NH₃, TS and pH tests as well as monitoring the settlement. The findings showed that the bioreactors with enzyme had faster decomposition rate than the control one. Final COD concentration in control one was 62.6% higher than the bioreactor having higher concentrations of enzyme. Similarly, final BOD₅ concentration in control one was 70.7% higher than the bioreactor having higher concentration of enzyme. Furthermore, the results were compared with the previous study, the bioreactors having municipal solid waste (MSW) with biosolids. The results showed that the strength of leachate quality was much better in bioreactors having paper waste with enzyme than the bioreactor having MSW with biosolids. The COD reduction rate in case of enzyme was about more than double than the bioreactor having biosolids. Similarly, BOD₅ reduction rate in case of enzyme was 1.6 times higher than the biosolids and TS reduction rate was about 1.4 times higher than the bioreactor having biosolids.

Investigation of leachate quality from the Trail Road Landfill

Leachate data for the Trail Road sanitary landfill were obtained for stages three (3) and four (4) of the landfill, located in the City of Ottawa, for the period of 10 years from 1996 to 2005. Data included several parameters such as pH, BOD, COD, Ca, Fe, Cl, SO₄, some selected heavy metals such as: Cu, Zn, Pb, and other parameters like Toluene and Vinyl Chloride. Analysis was performed to these data using Microsoft Excel analysis tools. Various graphical and statistical techniques such as Correlation, regression, and contaminant specific analysis were used to characterize leachate from the Trail Road Landfill. The data collected were fitted with trend lines to represent temporal variations. Pearson Product Moment correlation analysis as a multivariate statistical method was later used for identifying linear relationships between the quality of leachate with respect to the water infiltration to the waste, calculated from monthly precipitation data. Results from this research yielded noteworthy temporal variations of many parameters in leachate over the study period. Also, the effect of many factors like the net water infiltrating waste from precipitation and methanogenesis of leachate on the behaviour of leachate parameters was noticeable.

Stabilization of paper waste in bioreactor landfills using soybean peroxidase enzyme

One obvious way to reduce the amount of paper waste being discarded, and to conserve the forest resources, is to recycle more of the waste paper. But most common waste management technique for solid waste is the use of landfills. This study was aimed at decomposing the waste in aerobic condition before the anaerobic condition using soybean peroxidase enzyme (SBP). One bioreactor cell without enzyme was compared with two bioreactor cells, which contained different concentration of soybean peroxidase enzyme with hydrogen peroxide (H₂O₂). The rate of reaction was analyzed by performing COD, BOD₅, NH₃, TS and pH tests as well as monitoring the settlement. The findings showed that the bioreactors with enzyme had faster decomposition rate than the control one. Final COD concentration in control one was 62.6% higher than the bioreactor having higher concentrations of enzyme. Similarly, final BOD₅ concentration in control one was 70.7% higher than the bioreactor having higher concentration of enzyme. Furthermore, the results were compared with the previous study, the bioreactors having municipal solid waste (MSW) with biosolids. The results showed that the strength of leachate quality was much better in bioreactors having paper waste with enzyme than the bioreactor having MSW with biosolids. The COD reduction rate in case of enzyme was about more than double than the bioreactor having biosolids. Similarly, BOD₅ reduction rate in case of enzyme was 1.6 times higher than the biosolids and TS reduction rate was about 1.4 times higher than the bioreactor having biosolids.

Investigation of leachate quality from the Trail Road Landfill

Leachate data for the Trail Road sanitary landfill were obtained for stages three (3) and four (4) of the landfill, located in the City of Ottawa, for the period of 10 years from 1996 to 2005. Data included several parameters such as pH, BOD, COD, Ca, Fe, Cl, SO₄, some selected heavy metals such as: Cu, Zn, Pb, and other parameters like Toluene and Vinyl Chloride. Analysis was performed to these data using Microsoft Excel analysis tools. Various graphical and statistical techniques such as Correlation, regression, and contaminant specific analysis were used to characterize leachate from the Trail Road Landfill. The data collected were fitted with trend lines to represent temporal variations. Pearson Product Moment correlation analysis as a multivariate statistical method was later used for identifying linear relationships between the quality of leachate with respect to the water infiltration to the waste, calculated from monthly precipitation data. Results from this research yielded noteworthy temporal variations of many parameters in leachate over the study period. Also, the effect of many factors like the net water infiltrating waste from precipitation and methanogenesis of leachate on the behaviour of leachate parameters was noticeable.