Removal of Cu (II) and Cd (II) ions from environmental water samples by using Cellulose Acetate Membrane

Cellulose Acetate Membrane (CAM) which has been prepared by using a casting technique was utilized as an adsorbent for heavy metal ions adsorption. The CAM was characterized by Field Emission Scanning Electron Microscopy (FESEM), BET surface area (BET) and Fourier Transform Infrared Analysis (FTIR). The adsorption of Cu (II) and Cd (II) ions on CAM were investigated. The influences of several variables such as pH, adsorbance dosage, initial metal concentration, kinetic parameter, desorption and reusability on the adsorption capacity of the CAM was investigated in a batch adsorption mode. The adsorption capacity increased with the increasing of initial concentration of Cu (II) and Cd (II) solutions and followed the Freundlich model and pseudo second order kinetic mechanism. Desorption of metal ions was accomplished with 1 M Sulphuric acid and Hydrochloric acid solution for Cu (II) and Cd (II) ions. The adsorption capacity did not change significantly in reusability study when three adsorption experimental cycles were conducted. In conclusion, CAM is possible to be used as an alternative adsorbent for the removal of heavy metal ions from environmental water samples

Iminodiacetic acid modified kenaf fiber for waste water treatment

In the present study, iminodiacetic acid (IDA)-modified kenaf fiber, K-IDA formed by the chemical modification of plant kenaf biomass was tested for its efficacy as a sorbent material towards the purification of waste water. The K-IDA fiber was first characterized by the instrumental techniques like Fourier transform infrared (FTIR) analysis, elemental analysis (CHNSO), and scanning electron microscopy (SEM). On testing for the biosorption, we found that the K-IDA has an increment in the adsorption of Cu²⁺ ions as compared against the untreated fiber. The Cu²⁺ ions adsorption onto K-IDA fits very well with the Langmuir model and the adsorption maximum achieved to be 91.74 mg/g. Further, the adsorption kinetics observed to be pseudo second-order kinetics model and the Cu²⁺ ions adsorption is a spontaneous endothermic process. The desorption study indicates a highest percentage of Cu²⁺ of 97.59% from K-IDA under 1 M HCl solution against H₂SO₄ (72.59%) and HNO₃ (68.66%). The reusability study indicates that the efficiency did not change much until the 4th cycle and also providing enough evidence for the engagement of our biodegradable K-IDA fiber towards the removal of Cu²⁺ ions in real-time waste water samples obtained from the electroplating and wood treatment industries

Occurrence and distribution of endocrine-disrupting chemicals in mariculture fish and the human health implications

The presence and distribution of endocrine-disrupting chemicals (EDCs) in the mariculture fish from Pulau Kukup, Johor of Malaysia have been studied along with the impact on human health. Six different species of mariculture fish were collected, due to their high consumption in the Asian region—especially Malaysia, to assess their levels of EDCs. The highest concentration of EDCs detected in the muscle was dexamethasone (2.37–15.84 ng/g) and (0.77–13.41 ng/g), in the liver was dexamethasone (<2.54–43.56 ng/g) and progesterone (2.23–9.78 ng/g), and in the reproductive organ are dexamethasone (<2.54–37.23 ng/g) and caffeine (0.21–18.92 ng/g). The human health risk assessment in the current study suggested that there is no potential risk to the consumer because the hazard index was below 1 (HI < 1). The present study provides information on the pollution profile of EDCs and the associated human health risk with EDCs in mariculture fish

Removal of copper (II) ions by phosphoric acid and iminodiacetic acid modified kenaf fiber

Kenaf fiber can be chemically modified to enhancing their metal-binding ability by introducing new functional groups. The aim of this research was to prepare kenaf fiber (K) modified with phosphoric (K-PA) and iminodiacetic acid (K-IDA). The use of modified fiber for the removal of heavy metals which is Cu2+ is reported. The adsorbents is chemically modified with PA and IDA and in order to obtain the additional of functional group and the morphology in modified kenaf fiber, several characterization instruments were used such as Fourier Transform Infrared Analysis (FTIR), Elemental Analysis (CHNS), Scanning Electron Microscopy (SEM), Surface Area and Porosity Analysis (BET). K-PA and K-IDA show an increase in adsorption capacity of Cu2+when compared to the untreated fiber. The adsorption capacity of Cu2+ is in the following order: K-PA < K-IDA. Under the optimum conditions of pH 5 and a minimum of 0.1 g of adsorbent, K-PA and K-IDA adsorbsCu2+at amounts corresponding to the maximum adsorption efficiencies with percentages of removal of 90% and 99%, respectively. The adsorption capacity increased with increasing initial Cu2+ concentrations and followed the Langmuir model and pseudo second order kinetic mechanism for K-PA and K-IDA. The maximum sorption capacities as calculated from the Langmuir isotherm for K-PA and K-IDA were 64.52 and 91.74 mg g-1 respectively. Higher adsorption capacity at higher temperature indicates that the Cu2+ sorption process is endothermic for all adsorbents. The free energy changes, G for the sorption by K-IDA was negative indicating that the sorption process is spontaneous, while vice versa for K-PA. In the selectivity study, Kd for Cu2+ is higher than other heavy metal ions for K-IDA while Kd for Pb2+ is the highest value for K-PA. The foreign ion study showed that the sorption of Cu2+ was significantly affected by the presence of Cr3+, Pb2+ and Zn2+ except while with K-IDA. For the desorption study, it was observed the highest percentage desorption of Cu2+ towards K-PA and K-IDA was 95.41%, 99.46% respectively by using 1 M hydrochloric acid. For the reusability study, adsorption capacity for K-IDA did not vary until 4th cycle. Nevertheless, the adsorption capacity for K-PA suddenly decreases after the 2nd cycle. Both modified kenaf fibers, K-PA and K-IDA were found to be effective for the removal of Cu2+ in real wastewater samples obtained from electroplating waste and wood treatment industries. In conclusion, the modified kenaf fiber has potential to be used as effective heavy metal adsorbent for water treatment

A method for preparing a sorbent for removing heavy metals from wastewater

The present invention relates to a method for preparing a sorbent for removing heavy metals from wastewater. Generally, the material used is selected from biomass fiber especially kenaf and oil palm empty fruit bunch (OPEFB). The method is able to remove heavy metals detrimental to health such as mercury, cadmium, zinc, copper, and lead and with noble metals such as gold, platinum and silver from industrial wastewater exhausted from various industries

Metal-organic frameworks (MOFs) for the adsorptive removal of selected endocrine disrupting compounds (EDCs) from aqueous solution: A review

The progress of water-stable metal-organic frameworks (MOFs) has drawn interest from scientists to expand the research on this unique porous material, especially for the elimination of endocrine disrupting compounds (EDCs) from aqueous solutions via adsorption. Several controlling variables such as tunable porosity, hierarchical structure, immense pore volume and surface area, excellent adsorption and recyclability performances offer a new insight when compared with traditional adsorbents. The instability and toxicity of MOFs in water are a huge challenge in practical applications. Nevertheless, their capability and selectivity for the removal of EDCs can be justified by employing suitable metal ion clusters, organic linkers, and surface/bulk modifications. This review discusses the performance of several MOFs for the extermination of diverse categories of EDCs and the plausible adsorption mechanism involved. The importance of MOFs in environmental applications signifies that the development of advanced technology is required for the successful removal of EDCs from the aqueous environment

Occurrence, abundance, and distribution of microplastics pollution: an evidence in surface tropical water of Klang River estuary, Malaysia

Microplastics have been considered as contaminants of emerging concern due to ubiquity in the environment; however, the occurrence of microplastics in river estuaries is scarcely investigated. The Klang River estuary is an important ecosystem that receives various contaminants from urbanised, highly populated areas and the busiest maritime centre in Selangor, Malaysia. This study investigates the abundance and characteristics of microplastics in surface water of the Klang River estuary. The abundance of microplastics ranged from 0.5 to 4.5 particles L–1 with a mean abundance of 2.47 particles L–1. There is no correlation between the abundance of microplastics and physicochemical properties, while there is a strong correlation between salinity and conductivity. The microplastics were characterised with a stereomicroscope and attenuated total reflection–Fourier transform infrared spectroscopy to analyse size, shape, colour, and polymer composition. The microplastics in the surface water were predominantly in the 300–1000 μm size class, followed by > 1000 μm and < 300 μm, and were mostly transparent fibres, fragments, and pellets. Polyamide and polyethylene were the main polymer types in the composition of the microplastics, suggesting that the microplastics originated from heavily urbanised and industrial locations such as the port, jetty, and residential areas. The widespread occurrence of microplastics in the environment and subsequent penetration of aquatic food webs may pose a serious threat to organisms. This study provides baseline data and a framework for further investigation of microplastic contamination in estuaries

Accumulation and risk assessment of heavy metals employing species sensitivity distributions in Linggi River, Negeri Sembilan, Malaysia

The constant increase of heavy metals into the aqueous environment has become a contemporary global issue of concern to government authorities and the public. The study assesses the concentration, distribution, and risk assessment of heavy metals in freshwater from the Linggi River, Negeri Sembilan, Malaysia. Species sensitivity distribution (SSD) was utilised to calculate the cumulative probability distribution of toxicity from heavy metals. The aquatic organism’s toxicity data obtained from the ECOTOXicology knowledgebase (ECOTOX) was used to estimate the predictive non-effects concentration (PNEC). The decreasing sequence of hazardous concentration (HC5) was manganese > aluminium > copper > lead > arsenic > cadmium > nickel > zinc > selenium, respectively. The highest heavy metal concentration was iron with a mean value of 45.77 μg L–1 , followed by manganese (14.41 μg L–1 ) and aluminium (11.72 μg L–1 ). The mean heavy metal pollution index (HPI) value in this study is 11.52, implying low-level heavy metal pollutions in Linggi River. The risk quotient (RQ) approaches were applied to assess the potential risk of heavy metals. The RQ shows a medium risk of aluminium (RQm = 0.1125) and zinc (RQm = 0.1262); a low risk of arsenic (RQm = 0.0122) and manganese (RQm = 0.0687); and a negligible risk of cadmium (RQm = 0.0085), copper (RQm = 0.0054), nickel (RQm = 0.0054), lead (RQm = 0.0016) and selenium (RQm = 0.0012). The output of this study produces comprehensive pollution risk, thus provides insights for the legislators regarding exposure management and mitigation

Assessment of RNA extraction protocols from cladocerans.

The usage of cladocerans as non-model organisms in ecotoxicological and risk assessment studies has intensified in recent years due to their ecological importance in aquatic ecosystems. The molecular assessment such as gene expression analysis has been introduced in ecotoxicological and risk assessment to link the expression of specific genes to a biological process in the cladocerans. The validity and accuracy of gene expression analysis depends on the quantity, quality and integrity of extracted ribonucleic acid (RNA) of the sample. However, the standard methods of RNA extraction from the cladocerans are still lacking. This study evaluates the extraction of RNA from tropical freshwater cladocerans Moina micrura using two methods: the phenol-chloroform extraction method (QIAzol) and a column-based kit (Qiagen Micro Kit). Glycogen was introduced in both approaches to enhance the recovery of extracted RNA and the extracted RNA was characterised using spectrophotometric analysis (NanoDrop), capillary electrophoresis (Bioanalyzer). Then, the extracted RNA was analysed with reverse transcription polymerase chain reaction (RT-PCR) to validate the RNA extraction method towards downstream gene expression analysis. The results indicate that the column-based kit is most suitable for the extraction of RNA from M. micrura, with the quantity (RNA concentration = 26.90 ± 6.89 ng/μl), quality (A260:230 = 1.95 ± 0.15, A280:230 = 1.85 ± 0.09) and integrity (RNA integrity number, RIN = 7.20 ± 0.16). The RT-PCR analysis shows that the method successfully amplified both alpha tubulin and actin gene at 33-35 cycles (i.e. Ct = 32.64 to 33.48). The results demonstrate that the addition of glycogen is only suitable for the phenol-chloroform extraction method. RNA extraction with high and comprehensive quality control assessment will increase the accuracy and reliability of downstream gene expression, thus providing more ecotoxicological data at the molecular biological level on other freshwater zooplankton species

Occurrence and distribution of endocrine-disrupting chemicals in mariculture fish and the human health implications

The presence and distribution of endocrine-disrupting chemicals (EDCs) in the mariculture fish from Pulau Kukup, Johor of Malaysia have been studied along with the impact on human health. Six different species of mariculture fish were collected, due to their high consumption in the Asian region—especially Malaysia, to assess their levels of EDCs. The highest concentration of EDCs detected in the muscle was dexamethasone (2.37–15.84 ng/g) and (0.77–13.41 ng/g), in the liver was dexamethasone (<2.54–43.56 ng/g) and progesterone (2.23–9.78 ng/g), and in the reproductive organ are dexamethasone (<2.54–37.23 ng/g) and caffeine (0.21–18.92 ng/g). The human health risk assessment in the current study suggested that there is no potential risk to the consumer because the hazard index was below 1 (HI < 1). The present study provides information on the pollution profile of EDCs and the associated human health risk with EDCs in mariculture fish