Abstract: Pollutants from aquacultural practices constitute environmental problems and phytoremediation could offer cheaper environmentally sustainable alternative since equipment using advanced treatment for fish tank effluent is expensive to import, install, operate and maintain, especially in developing countries. The main objective of this research was, therefore, to develop a mathematical model for phytoremediation by aquatic plants in aquaculture wastewater. Other objectives were to evaluate the retention times on phytoremediation rates using the model and to measure the nutrient level of the aquaculture effluent and phytoremediation rates of three aquatic macrophytes, namely; water hyacinth (Eichornia crassippes), water lettuce (Pistial stratoites) and morning glory (Ipomea asarifolia). A completely randomized experimental design was used in the study. Approximately 100 g of each macrophyte were introduced into the hydroponic units and phytoremediation indices monitored at 8 different intervals from the first to the 28th day. The water quality parameters measured were pH and electrical conductivity (EC). Others were concentration of ammonium–nitrogen (NH4+ -N), nitrite- nitrogen (NO2- -N), nitrate- nitrogen (NO3- -N), phosphate –phosphorus (PO43- -P), and biomass value. The biomass produced by water hyacinth was 438.2 g, 600.7 g, 688.2 g and 725.7 g at four 7–day intervals. The corresponding values for water lettuce were 361.2 g, 498.7 g, 561.2 g and 623.7 g and for morning glory were 417.0 g, 567.0 g, 642.0 g and 679.5g. Coefficient of determination was greater than 80% for EC, TDS, NO2- -N, NO3- -N and 70% for NH4+ -N using any of the macrophytes and the predicted values were within the 95% confidence interval of measured values. Therefore, the model is valuable in the design and operation of phytoremediation systems for aquaculture effluent.
Abstract: Roles of the vegetation to mitigate the erosion of the
stream bed or to facilitate the deposition of the fine sediments by the
species of the aquatic plants were presented. Field investigation on the
estimation of the change of the bed level and the estimation of the flow
characteristics were performed. The results showed that Phragmites
japonica has the mitigation function of 0.3m-0.4m of the erosion in the
range of higher than 1.0m/s of flow velocity at the vegetated region.
Phragmites communis has the mitigation function of 0.2m-0.3m of the
erosion in the range of higher than 0.7m/s of flow velocity at the
vegetated region. Salix gracilistyla has greater role than Phragmites
japonica and Phragmites communis to sustain the stable channel. It
has the mitigation function of 0.4m-0.5m of the erosion in the range of
higher than 1.4m/s of flow velocity. Miscanthus sacchariflorus has a
weak role compared with that of Phragmites japonica and Salix
gracilistyla, but it has still function for sustaining the stable bed. From
these results, the vegetation has effective roles to mitigate the erosion
or to facilitate the deposition of the stream bed.
Abstract: In this study, the effectiveness of an integrated aquatic
plants in phytogreen zone was studied and statistical analysis for the
promotional integrated phytogreen system approached was discussed.
It was found that's the effectiveness of using aquatic plant such as
Typha angustifolia sp., Lepironia articulata sp., Limnocharis flava
sp., Monochoria vaginalis sp., Pistia stratiotes sp., and Eichhornia
crassipes sp., in the conventional oxidation pond process in order to
comply the standard A according to Malaysia Environmental Quality
Act 1974 (Act 127); Environmental Quality (Sewage) Regulation
2009 for effluent discharge into inland water near the residential area
was successfully shown. It was concluded that the integrated
phtogreen system developed in this study has great potential for
refurbishment wastewater in conventional oxidation pond.
Abstract: To improve the water quality of lakes and control algae blooms, the effects of Vallisneria asiatica which is one of aquatic plants spread over Lake Taihu, with different biomasses on the water quality and algae communities were researched. The results indicated that V. asiatica could control an excess of Microcystis spp. when the V. asiatica biomass was larger than 50g in the tank with 30L solution in the laboratory. Planktonic and epiphytic algae responded differently to V. asiatica. The presence of macrophyte V. asiatica in eutrophic waters has a positive effect on algae compositions because of different sensitivities of algae species to allelopathic substances released by macrophyte V. asiatica. That is, V. asiatica could inhibit the growth of Microcystis spp. effectively and was benefited to the diatom on the condition in the laboratory.
Abstract: The aquatic plants are a promising renewable energy resource. Lake Fúquene polluting macrophytes, water hyacinth (Eichhornia crassipes C. Mart.) and Brazilian elodea (Egeria densa Planch.), were saccharifiedby different treatments and fermented to ethanol by native yeasts. Among the tested chemical and biological methods for the saccharification, Pleurotus ostreatus at 10% (m/v) was chosen as the best pre-treatment in both macrophytes (P
Abstract: Study was conducted to determine the concentration of
copper, cadmium, lead and zinc in Cabomba furcata that found
abundance in Lake Chini. This aquatic plant was collected randomly
within the lake for heavy metal determination. Water quality
measurement was undertaken in situ for temperature, pH,
conductivity and dissolved oksigen using portable multi sensor probe
YSI model 556. The C. furcata was digested using wet digestion
method and heavy metal concentrations were analysed using Atomic
Absorption Spectrometer (AAS) Perkin Elmer 4100B (flame
method). Result of water quality classify Lake Chini between class II
to class III using Malaysian Water Quality Standard. According to
this standard, Lake Chini has moderate quality, which normal for
natural lake. Heavy metal concentrations in C.furcata were low and
found to be lower than the critical toxic value in aquatic plants. Oneway
ANOVA test indicated the heavy metal concentrations in
C.furcata were significantly differ between sampling location. Water
quality and heavy metal concentrations indicates that Lake Chini was
not receives anthropogenic load from nearby activities.