Effect of different techniques of composting on stability and maturity of municipal solid waste compost

Abstract

Three methods for composting, aerobic, anaerobic and mixed type were compared in three locally fabricated composters of 20 L each, for their effect in accelerating compost maturity and stability using municipal solid waste. The composting process was monitored through determining the changes in temperature, pH, ammonium-N (NH(+)4-N), nitrate-N (NO- 3-N), carbon/nitrogen (C/N) ratio, NH(+)4-N/NO(-)3-N, total carbon, nitrogen (TN), potassium (TK), phosphorous (TP), humification index (HI), degree ofpolymerization (DP), humification rate (HR), CO2, humic acid (HA), fulvic acid (FA), and cation exchange capacity (CEC). Temperature increased rapidly from the mesophilic to the thermophilic stage and gradually decreased near the maturation phase. A similar behaviour was recorded for pH, which become slightly alkaline at the maturity level. The composting process decreases the concentration of total carbon, NH(+)4-N, C/N ratio, and CO2, and increases CEC, HI, DP, HA, TP, TK, and TN. All three composting methods used in this study produce mature compost at different time intervals. A high statically significant correlation was found between the total carbons, C/N ratio, HA, FA, DP, HI, HR, CEC, and ammonium nitrate ratio.

Optimization of process parameters for kitchen waste composting by response surface methodology

“…This ratio represents the forms of organic carbon and nitrogen in the composting mixture that are more susceptible for microbial transformation and for compost stability and maturity (Said-Pullicino et al 2007). Iqbal et al (2010a) findings are coherent to the present findings.…”

“…Hence, it limits the ability to absorb the leachate during kitchen waste composting. Iqbal et al (2010a) used saw dust (40 %) as bulking agent during the optimization of physical properties of MSW compost and found the attractive results and the present study results are also inline with Guo et al (2012). The trials 2, 5 and 13 are illustrated in Fig.…”

“…Bulking agents have the property to modify the physical (bulk density, FAS) and chemical (C/N) properties of compost. They not only absorb the moisture contents but also impact on the C/N ratio of the compost (Iqbal et al 2010a). Fly ash is a product of combustion, contains macro nutrients (CaO, Na, K), perk up the physical and chemical characteristics of compost along with reduction in moisture from the composting matrix.…”

“…The kitchen waste, bulking agent and fly ash were mixed as per design format in plastic containers for periods of 7 days under controlled laboratory conditions (T: 25°C; H: 50 %) and calculated the potential of moisture reduction as prescribed by Iqbal et al (2010a). The quantities of raw materials processed during moisture optimization were presented in Table 2.…”

Comparative effectiveness of different composting methods on the stabilization, maturation and sanitization of municipal organic solid wastes and dried faecal sludge mixtures

“…Composting methods differ in duration of decomposition and potency of stability and maturity (Iqbal et al 2012). Due to the ecological and health concerns of human wastes, extensive research has been conducted to study the composting process and to evaluate methods to describe the stability, maturity and sanitation of compost prior to its agricultural use (Brewer and Sullivan 2003;Zmora-Nahum et al 2005 (Dominguez et al 1997;Frederickson et al 1997;Ndegwa and Thompson 2001;Tognetti et al 2005Tognetti et al , 2007Lazcano et al 2008;Mupondi et al 2010), information on the effectiveness of the different composting methods on biodegradation and sanitization of mixtures of MSW and dried faecal sludge (DFS) is scant.…”