Effectiveness of Lagoon in improving water quality of discharge from farms in Samarahan area

The main objective of this research is to study the efficiency of different lagoon system in improving the wastewater quality before being discharged to public watercourse. This study involved four pig farms with different lagoon systems namely single lagoon, double lagoon (with and without separator) and triple lagoon. The parameters examined were temperature, dissolved oxygen (DO), biochemical oxygen demand (BODs), total suspended solid (TSS), ammonia nitrogen (NH}-N) and total phosphorus (TP). Result shows that the triple lagoon system farm was the most efficient in BODs (93.9%), TSS (92.7%), NH}-N (85.5%) and TP (92.6%) removal. The double lagoon farm has least emcient in NH)-N removal while the double Ingoon system with separator show no TP removal. The Interim National Quality Standard of Malaysia (lNWQS) was used to classify the water quality parameters. The parameters for DO, BODs, NHrN and TP were in Class IV -V. However, TSS was in Class I -III. Statistical analysis shows that there is significant difference in percent reduction of BODs and NH}-N between each farm. While the double lagoon with separator was significantly different in reduction (%) of TSS compared to the double and triple lagoon farm. The triple lagoon farm showed significant difference in reduction (%) of TP when compared to two of the double lagoon farm (with and without separator). All the lagoons are likely anaerobic due to the low level of DO. This study shows that most of the treatment occurred in the second lagoon. It is recommended that proper lagoon management such as scheduled maintenance and work should be practiced to improve the treatment of the wastewater in lagoon system before being discharge to the watercourse