Availability and quality of solid waste and wastewater in Southern Thailand and its potential use as fertiliser

Recycling nutrients to agriculture with waste in Southern Thailand has been assessed in three model-areas: Kuan Lang, Prik and Phattalung. Samples of biodegradable solid waste and gray wastewater were collected and characteris ed physically and chemically. At present nutrients in the biodegradable solid waste and wastewater are lost, but especially kitchen waste and grey household wastewater constitute a large fertiliser potential.

The average daily per capita generation rate of household kitchen waste is 228 g wet matter, 0.65 gN, 0.16 gP, 0.34 gK, 0.05 gS, 0.39 gCa, 0.06 gMg, 6.9 mgZn, 0.29 mgCu, 0.05 mgNi, 0.02 mgPb, 0.09 mgCd and 0.006 mgHg. The average daily per capita generation rate of grey household wastewater is 102 L, 2.4 gN, 2.4 gP, 4.2 gK, 2.0 gS, 2.2 gCa, 0.82 gMg, 42 mgZn, 0.91 mgCu, 1.6 mgNi, 0.46 mgPb, 0.20 mgCd and <0.06 mgHg.

The waste products generally contain higher amounts of K, Ca, Mg, Zn, Cu and Pb (relative to phosphorous) than conventional chemical fertiliser, while N, S, Ni, Hg and Cd is at the same level.