Tasik Puteri is a recreational lake for few activities such as scuba diving, kayaking and swimming during the dry season. However, this lake was an iron ore mining site and the remaining contaminants and heavy metal of the lake can harm the people that directly get into contact with the lake water. The present study focused on investigating the phytoremediation potential of locally available floating aquatic plants in the treatment process of water from Tasik Puteri, which was contaminated with mining effluent. The effluent was treated with water hyacinth (Eichhornia crassipes) and water lettuces (Salvinia molesta and Pistia stratiotes) in a constructed wetland for a period of 28 days. The effluent treatment efficiency was estimated by measuring the effluent quality over the experimental period. Five water parameters such as the total iron (TI), total phosphorus (TP), chemical oxygen demand (COD), electrical conductivity (EC) and turbidity were examined using standard laboratory procedures, which include. The results indicated that the three plants were able to remove the contaminants. After 28 days, the physical observation shows that the water hyacinth was healthier than the water lettuces. Considerable decrements in concentration were recorded in TI, TP and EC, but fluctuation in COD and turbidity value were observed. Comparison results by the plants indicat that after 28 days, water hyacinth was the most effective plant in removing phosporus, COD and EC of the mining lake with 97.3%, 70.5% and 22.2% removal, respectively. Furthermore, water lettuce (P. stratiotes) was the most effective plant in removing Iron (96.0%) and the turbidity (50.0%) of the mining lake. S. molesta showed the lowest removal capability for all experimental parameters. In conclusion, water hyacinth and water lettuces had shown better capability in removing heavy metals and other contaminants with E. crassipes has the highest survivability in the lake water.

Poor water quality due to heavy metal content in Tasik Puteri can harm people that directly get into contact with it for recreational activities. Thus, this study investigated the phytoremediation potential of locally aquatic plants to remediate the lake water. Scirpus grosus and Eleocharis dulcis were planted in constructed wetlands for 28 days. The water analysis was performed to measure turbidity, total iron (TI), total phosphorus (TP), chemical oxygen demand (COD) and electrical conductivity (EC). After 28 days, S. grosus was observed to be healthier. Fluctuation readings were recorded in turbidity value and considerable decrements in TI, TP, COD and EC. S. grosus exhibits higher removal of TI, EC and turbidity which 95.45%, 32.89% and 40.00% removal respectively, whilst E. dulcis removed 65.28% of COD. Both plants demonstrated comparable TP removal with 92.04% and 91.04% by S. grosus and E. dulcis respectively. In conclusion, S. grosus is proven as the more effective phytoremediator.

Over the past eight decades, numerous research has been conducted on the extraction of Zingiber zerumbet rhizome. The mini-review includes information on the pharmacological properties of zerumbone extracted from Z. zerumbet rhizome and the extraction methods conducted over the previous 80 years. Zerumbone is recognised as having a proven pharmacological effect and is a significant medicinal component used to treat various ailments. The pharmacological values are stated based on the research findings. The extraction method and technology are essential to extract zerumbone. Thus, the review helps the reader keep up with the history of each technique or technology used in extracting zerumbone from Z. zerumbet rhizome, starting with conventional technology and moving toward advanced technology.

Extraction is crucial for herbal extraction to ensure high quality of bioactive compounds from natural herbs. In the current work, Zingiber Zerumbet was extracted via subcritical water extraction (SWE) and is compared with the conventional solvent extraction, Soxhlet. The quality of the extract was investigated in terms of zerumbone concentration, radical scavenging activity (RSA) and total phenolic content (TPC). For zerumbone concentration, extraction via SWE gave 19.82 ±0.004 mg/g as compared with Soxhlet; 28.51±0.079 mg/g. However, the extraction time required for SWE to yield such concentration only required 40 minutes instead of Soxhlet which took 480 minutes. The same trend was recorded for RSA, which yielded 60.70±0.070% inhibition for SWE and 68.81±0.024% inhibition from Soxhlet extraction. In contrast to TPC, SWE recorded a higher response than Soxhlet extraction, which was 19.19±0.003 mgGAE/g DW, while Soxhlet; 8.30±0.019 mgGAE/g DW. Therefore, the SWE method is more favorable for obtaining a higher value of TPC, slightly good in antioxidant properties but lower zerumbone concentration value than organic solvent extraction. However, the reduced extraction time was almost 12 times quicker for SWE when compared with Soxhlet extraction. Overall, SWE is a promising alternative environmentally friendly since it only uses water as solvent and is comparable to the conventional method.