Conclusion

The study brings out the role of actors involved in open deg- radation of mixed OFMSW, degradation pattern and the rate kinetics of waste degradation in open dumpsites. The mixed organic matter lost moisture content rapidly during the early stages of degradation and the degradation rate slowed down subsequently and stabilized. In such a degradation process 48% of VS was degraded till the moisture content reached levels > 60% in the first 6 days of degradation. After this, only 14% of VS was lost during 6–30 days of degradation period. The result confirms the involvement of micro and meso + micro categories. Soil contact has no significant effect (source of inoculum) on the rate of waste degradation. Across the different categories, when the moisture content reaches 50–60%, there is a maximum level of reduction of waste VS content. This reduction was greater in micro and meso + microorganism categories. This suggested that longer such ‘appropriate’ moisture content is maintained, greater is the involvement of microorganisms leading to enhanced biodegradation of the organic fraction. There is a reduction in C, N, and H mass with the involvement of different sizes

Table 2 Degradation pattern and rate kinetics of different conditions

Details

Organism

Soil contact

Micro

Meso + micro

NSC

PSC

SC

VS0 (g/kg)

180.727

180.727

176.331

176.331

176.331

Pattern

y = 132.97e−0.0643x

y = 132.58e−0.0629x

y = 154.18e−0.0353x

y = 170.43e−0.0582x

y = 145.75e−0.0325x

R2

0.8945

0.8468

0.8823

0.8396

0.724

Phase I

Period (days)

0–8

0–8

0–6

0–6

0–6

Kinetics

Zero order

Zero order

Zero order

Zero order

Zero order

K (g/kg/day)

24.88584

22.75678

14.88066

15.7474013

16.60726

Phase II

Period (days)

8–30

8–30

6–30

6–30

6–30

Kinetics

First order

First order

First order

First order

First order

K (/day)

0.049

0.075

0.036

0.03

0.024

of organisms and with different types of soil contact. Degra- dation of VS is an exponential decay function during the first ‘moist’ period of decomposition and latter with first-order rate kinetics when MSW dries in open dumpsites.

Acknowledgements The authors are grateful to the Indian Institute of Science for infrastructure support. The authors would like to thank Ms. Naqiyya J. for help in conducting experiments. The financial support for this study was provided by the Bangalore City Corporation (Bruhat Bengaluru Mahanagara Palika, BBMP) and is gratefully acknowledged.

Declarations

Conflict of interest The authors declare no potential conflict of interest regarding the publication of this work. In addition, the ethical issues including plagiarism, informed consent, misconduct, data fabrication and, or falsification, double publication and, or submission, and redun- dancy have been completely witnessed by the authors.