Degradation of water quality due to the presence of pollutants in water is an emerging issue in many countries, including Malaysia. Phytoremediation is one of the environmentally friendly, cost-effective conventional technologies that are still used in modern times. However, the selection of plant species is the most important aspect for the application of phytoremediation in wastewater treatment. Nevertheless, there are species of floating aquatic macrophytes that are capable of coping with various pollutants present in wastewater. Among the various floating aquatic macrophyte species, water hyacinth (WH) and water lettuce (WL) have been described as effective phytoremediators in reducing water pollution through bioaccumulation in their body tissues. Hence, WH and WL were chosen in this study as it is easily found, propagated, and cultivated. This paper aims to determine the biosorption capacity of these species in eliminating various pollutants present in wastewater as well as to define the optimum harvesting time for each species. Although these floating aquatic macrophytes are considered the most problematic plants due to their uncontrollable growth in water bodies worldwide, their ability to remove pollutants from wastewater has created a sustainable approach for their use in phytoremediation. In this sense, the use of phytoremediation by implementing the invasive floating aquatic macrophytes can certainly support the sustainable management of wastewater treatment in the future. Based on the results, it was found that WH efficiently removed higher PO43-, NO3- and NO2- concentrations compared to WL from the wastewater. Both WH and WL showed the same trend of correlation between the growth rate and sugar content, where the sugar content increased when the plants reached the highest growth rate. The maximum nutrient uptake occurred in 14-17 days, proving that nutrient availability is critical for plant growth. This study concludes that the sugar content of WH and WL are increased with the biomass growth rate, and both plants species are competent in eradicating the nutrient pollution in wastewater. On top of that, this study infers that the maximum harvesting period for WH biomass is on day 18, while WL biomass is on day 21; based on the highest sugar content and biomass weight of each species.

To elucidate the efficacy of eco-enzyme in mediating contaminated waters, an onsite investigation was conducted spanning over a 5-month duration on three ponds receiving iron-containing groundwater continuously. Eco-enzyme was applied at designated dosages and time. Water samples were collected fortnightly for in situ monitoring of water quality. Parameters determined included total suspended solids (TSS), pH, alkalinity, chemical oxygen demand (COD), biochemical oxygen demand (BOD 5 ), ammoniacal-nitrogen (NH 3 ), and dissolved oxygen. During the investigation, ecoenzyme application was halted for nearly a month owing to the enforcement of Movement Control Order to curb the rising Covid-19 cases. The results revealed that the application of eco-enzyme has improved the overall water quality of the three ponds.A 99.9% of TSS removal was achieved. For the other parameters measured, the concentration fluctuated over time and the water quality status of the pond interchanged between slightly polluted and clean. The elevation of the water quality was largely dependent on the frequency of the eco-enzyme application. This study, therefore, concludes that eco-enzyme possessed the capability to enhance the quality of contaminated water.

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Annually, enormous amount of palm oil mill effluent (POME) ranging between 56.58 to 70.55 million m 3 are producedduring the production of palm oil. Its acidic and high organic loading characteristics can cause severe water pollution if discharged without proper treatment. In Malaysia, most oil palm production mills adopted ponding treatment system. However, this treatment requires high retention time and large build area. Thus, the treatment paradigm has shifted tointegrated high rate bioreactors by coupling anaerobic and aerobic processesdue to the incompetency of the conventional treatment in complying the standard effluent discharged outlined by the Department of Environment.Despite the outstanding treatment performance exhibited by this bioreactor, diluted POME was used in almost all previous studies instead of fresh raw POME. Therefore, the researched bioreactors may not be as efficient in real application. This present study aimed to employ the principle of two-stage anaerobic process followed by a single stage aerobic process for the treatment of fresh raw POME, in whicha two-stage upflow anaerobic sludge blanket digester was integrated with a single-stage anaerobic packed bed reactor. This is to ensure the lignocellulosic components will be broken down into simpler organic compounds in the first stage anaerobic bioreactor followed by their reduction in the second stage anaerobic and single stage aerobic bioreactors.With this, the potential mechanical problems and inhibition on the operational interference of the currently available integrated system is rectified. Thus, the overall performance can be enhanced.The treatment efficiency of this system was examined by evaluating the removal of several important parameters, namely chemical oxygen demand (COD) and sludge reduction reported in terms of total suspended solids (TSS). Throughout the 150 days of operation, approximately 93% and 55% of reduction were observed for COD and TSS, respectively, suggesting this integrated system was competent in treating high strength wastewater.Nonetheless, further research need to be made to ensure the stability consistency and feasibility of this integrated system. KEYWORDS raw palm oil mill effluent, two-stage anaerobic, aerobic, chemical oxygen demand (COD), total suspended solid (TSS).

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