Sewage sludge, collected from a residential area in Kuching, Sarawak, Malaysia was successfully used as a nitrogen source using landscape and agricultural crops biomass to produce compost.
The composting method developed was able to eliminate the pathogenic microorganisms found in raw sewage sludge without lime. Conventionally, a large amount of lime was used to eliminate the microorganisms by way of raising the pH from 7 to 12. This composting is time-saving as it takes less than 40 days to produce compost from the sludge.
Now there is no hassle of providing land to dispose the non-biodegradable polystyrene bags of the treated sludge (which was dangerous to the environment). Another environment saving is that it does not use lime since the composting process readily eliminated the pathogenic microorganism. This also saves the high cost of liming.
The compost is highly recommended to plant growers and nursery propagation operators. It accelerates the growth of plants that nursery operators can sell their propagated plants one month earlier than those using fertilizers from chicken manure or compost with Potassium. Other than that, the bio-solid compost can itself be sold as a product.
Margaret Chan, PhD
Khong Heng Yen
Zayn Gregory Al-Abidin
Faculty of Applied Sciences
UiTM, Sarawak, Malaysia
Ong Mooi Lian, PhD
Faculty of Civil Engineering
Research management Institute