การจัดการสลัดจ์ส่วนเกินจากระบบบำบัดน้ำเสียแบบแอกติเวเต็ดสลัดจ์ของอุตสาหกรรมน้ำยางข้น

Abstract

This study is about management of excess sludge from activated sludge wastewater treatment system of concentrated latex industry. The study aims to find the suitable usage and effective management process for the excess sludge. The results showed that activated sludge technology has been increasing for wastewater treatment in the concentrated latex factories in the South of Thailand. However, there are the problems due to excess sludge management from the activated sludge which need to be developed. With investigation, the excess sludge from activated sludge wastewater treatment system of concentrated latex industry generation rate was determined as for 3.1 ton/day average value). The excess sludge had a low C/N ratio and contained TKN, P, and K with the average values of 8.0, 2.0, and 1.0% dry basis, respectively. Moreover, the excess sludge had a high Zn. There is potential of chemical used for sludge conditioning. From the result of experiments, applying alum 0.1 g/1 L sludge mixed with polyacrylamide with 0.1 g/1 L sludge sludge at pH 8 indicated that the capillary suction time and specific resistance is that the best conditions of chemical used for sludge conditioning. Concerning biological sludge treatment for recycling by Biochemical Methane Potential (BMP), in term of biogas production in 30 days, the results showed that the excess sludge from activated sludge process experiment without chemical used in sludge conditioning, (Al), could produce biogas yield and methane yield with maximum rate of 0.163 m' biogas/1 kg VS removal and 0.081 CH,/kg VS removal respectively. In addition, the investigation on the possible use of the obtained compost products as fertilizer on plant growth was conducted. These experiments were set up with high MC and low C/N ratios, with ranges of 3.2:1 to 5.9:1 of composting of excess sludge from concentrated latex factories. The composting experiments were investigated based on test conditions of different compost materials used (mixture of excess sludge, ash, and coconut husk), with and without aeration, as well as with and without seeding. The slow decomposition of OC occurred during 90 days composting. The results indicated that the composting of mixtures of excess bio-sludge, ash, and coconut husk with and without seeding and aeration made compost products compliant with Thai organic fertilizer standards, especially in terms of pH, P,s, K,O, As, Cd, Cr, Cu, Pb, and Hg, but not for MC, OM, electrical conductivity and germination index. With the results tested on plant growth, the possibility of the use of compost products as fertilizer as experimented with marigolds, illustrated that compost products from a mixture of excess bio-sludge, ash, and coconut husk without seeding and aeration had potential to be used as fertilizer which was equivalent to 15:15:15 chemical fertilizer, in particular in terms of plant height increase rate and numbers of flowers achieved.