Adsorption of Cu2+ Ions using Rubber-Based Hydrogel

Hydrogels are one of the most powerful adsorbents for removing heavy metal ions among all adsorbents. However, most of today's hydrogels are synthetic polymers with high costs, non-environmentally friendly, and have low stability. Therefore, in this study, natural rubber (NR) was used as the basic material for hydrogels due to its high mechanical properties, plasticity or viscosity, elasticity, and tensile strength. This study is focusing on the Cu adsorption method using a rubber-based hydrogel that is prepared with a combination of acrylic acid (AA) and methylenebisacrylamide (MBA). The rubber-based hydrogel was immersed in the synthetic Cu wastewater, and the percentage removal was calculated. Cu initial concentration, contact time, and rotation speed were the three independent variables used for optimization using Response Surface Methodology (RSM). With an initial Cu concentration of 47.66 mg/L, a contact time of 10 hours, and a rotation speed of 91.32 rpm, RSM optimization shows that the best conditions for Cu removal are 72.19%. The SEM-EDX micrograph of the hydrogel before adsorption shows numerous pores, but after adsorption it is smoother and has fewer holes. This study will contribute to the development of a new method to remove Cu from wastewater

Heavy metals concentration in “etak” tissue at different processing stages

Corbicula fluminea, known as “etak” in Kelantan, Malaysia is a freshwater bivalve. This clam is widely consumed as traditional snack by the locals. However, lately there are numerous reports in local newspapers that claim “etak” to cause health effects due to eating contaminated “etak”. Hence, this study aims to determine the heavy metals concentration in fresh, smoked and exposed “etak” sold at the stall as a baseline study in order to develop a method for removing the heavy metals content in its tissues. This study involves sample collection in the stalls around Kelantan, sample preparations via acid digestion and heavy metal determination using Perkin Elmer PinAAcle 900F Atomic Absorption Spectrometer. The results showed the heavy metals (Cr, Zn, Mn and Cu) concentrations (μg/g) in all “etak” tissue were at different level for fresh (Cr: 1.02±0.35ppm, Zn: 74.57±2.76ppm, Mn: 40.22±9.96ppm and Cu: 15.27±1.41ppm), smoked (Cr: 0.42±0.02ppm, Zn: 54.62±17.83ppm, Mn: 50.13±2.31ppm and Cu: 20.94±8.81ppm) and exposed (Cr: 0.53±0.08ppm, Zn: 63.07±8.44ppm, Mn: 50.41±6.92ppm and Cu: 12.80±0.40ppm) samples. The results obtained were compared with the permissible limits set by Malaysian Food Regulations 1985 (Cu: 30.0ppm and Zn: 100.0ppm), FAO/WHO 1984 (Mn: 5.4ppm) and IAEA – 407 (Cr: 0.75ppm). For fresh “etak”, Zn and Cu concentration were below the standards, while Mn and Cr were exceeded the permissible limits. For smoked “etak” and exposed “etak” at stall, all heavy metals concentration were within the permissible limits, except Mn contents. This study successfully determine the baseline concentration of the heavy metals in “etak”

Heavy metals concentration in “etak” tissue at different processing stages

Corbicula fluminea, known as “etak” in Kelantan, Malaysia is a freshwater bivalve. This clam is widely consumed as traditional snack by the locals. However, lately there are numerous reports in local newspapers that claim “etak” to cause health effects due to eating contaminated “etak”. Hence, this study aims to determine the heavy metals concentration in fresh, smoked and exposed “etak” sold at the stall as a baseline study in order to develop a method for removing the heavy metals content in its tissues. This study involves sample collection in the stalls around Kelantan, sample preparations via acid digestion and heavy metal determination using Perkin Elmer PinAAcle 900F Atomic Absorption Spectrometer. The results showed the heavy metals (Cr, Zn, Mn and Cu) concentrations (μg/g) in all “etak” tissue were at different level for fresh (Cr: 1.02±0.35ppm, Zn: 74.57±2.76ppm, Mn: 40.22±9.96ppm and Cu: 15.27±1.41ppm), smoked (Cr: 0.42±0.02ppm, Zn: 54.62±17.83ppm, Mn: 50.13±2.31ppm and Cu: 20.94±8.81ppm) and exposed (Cr: 0.53±0.08ppm, Zn: 63.07±8.44ppm, Mn: 50.41±6.92ppm and Cu: 12.80±0.40ppm) samples. The results obtained were compared with the permissible limits set by Malaysian Food Regulations 1985 (Cu: 30.0ppm and Zn: 100.0ppm), FAO/WHO 1984 (Mn: 5.4ppm) and IAEA – 407 (Cr: 0.75ppm). For fresh “etak”, Zn and Cu concentration were below the standards, while Mn and Cr were exceeded the permissible limits. For smoked “etak” and exposed “etak” at stall, all heavy metals concentration were within the permissible limits, except Mn contents. This study successfully determine the baseline concentration of the heavy metals in “etak”

Removal of chromium (VI) using chitosan-immobilized acinetobacter haemolytics

This important book discusses the ethical code regarding possible introduction of exogenous bacterial species into the environment, as well as various other applications of bacteria in environmental biotechnology

Adsorption of Cu

Hydrogels are one of the most powerful adsorbents for removing heavy metal ions among all adsorbents. However, most of today's hydrogels are synthetic polymers with high costs, non-environmentally friendly, and have low stability. Therefore, in this study, natural rubber (NR) was used as the basic material for hydrogels due to its high mechanical properties, plasticity or viscosity, elasticity, and tensile strength. This study is focusing on the Cu adsorption method using a rubber-based hydrogel that is prepared with a combination of acrylic acid (AA) and methylenebisacrylamide (MBA). The rubber-based hydrogel was immersed in the synthetic Cu wastewater, and the percentage removal was calculated. Cu initial concentration, contact time, and rotation speed were the three independent variables used for optimization using Response Surface Methodology (RSM). With an initial Cu concentration of 47.66 mg/L, a contact time of 10 hours, and a rotation speed of 91.32 rpm, RSM optimization shows that the best conditions for Cu removal are 72.19%. The SEM-EDX micrograph of the hydrogel before adsorption shows numerous pores, but after adsorption it is smoother and has fewer holes. This study will contribute to the development of a new method to remove Cu from wastewater

Photocatalytic degradation of glyphosate using TiO2/Al2O3/CNT

Excessive use of glyphosate in agriculture has a negative impact on the environment because it causes runoff, which affects water sources and causes pollution. Advanced Oxidation Process (AOP) is the method for resolving water contamination concerns, and photocatalytic degradation using TiO2/Al2O3/CNT nanocomposites has been observed to be a reliable solution for degrading glyphosate. The photocatalyst of TiO2/Al2O3/CNT nanocomposite was prepared using various ratios which were 70:20:10, 70:29:1 and 70:30:0. These photocatalysts TiO2/Al2O3/CNT were prepared using hydrothermal process. The prepared TiO2/Al2O3/CNT photocatalyst nanocomposite has been applied to degrade glyphosate in order to assess its performance. Hence, the effect of initial glyphosate concentration and amount of photocatalyst used during photocatalytic degradation of glyphosate were investigated. This study found that 20 mg of 70:30:0 ratio TiO2/Al2O3/CNT nanocomposite photocatalyst gave the highest percentage degradation of 5 mg/L of glyphosate which was 84.9%. The lowest degradation percentage for 5 mg/L of glyphosate was 68.2% using the 5 mg of ratio 70:20:10 TiO2/Al2O3/CNT nanocomposite photocatalyst. Finally, the prepared photocatalyst was beneficial in degrading herbicide

Health risk assessment of heavy metals from smoked Corbicula fluminea collected on roadside vendors at Kelantan, Malaysia

Corbicula fluminea serves as traditional food to the local people in Kelantan, Malaysia. Concerns regarding river contamination, smoking method, and associated adverse effects on public health had been increasing. Hence, this study aims to measure the level of heavy metals (Cd, Cu, Mn, Pb, and Zn) and assess human health risk in C. fluminea consumption at Kelantan. Heavy-metal analysis was done using flame atomic absorption spectrophotometry, while human health risk was assessed using provisional tolerable weekly intake (PTWI), target hazard quotient (THQ), and hazard index (HI). The estimated weekly intake (EWI) for all metals was found within PTWI, while THQ for Cd, Cu, Mn, Pb, and Zn was 0.12, 0.06, 0.04, 0.41, and 0.03, respectively. The HI was calculated at 0.61 which is less than 1, considered as the safe consumption level. Therefore, C. fluminea consumption in this study was found safe from the health risk of noncarcinogenic effect over a lifetime

Microbial biotransformation and biomineralization of organic-rich waste

Purpose of Review: Improper discharge of industrial effluents would lead to direct contamination of our water, air, and soil systems. Without proper treatment, both these inorganic and organic-matter-containing waste would pose harmful effects towards aquatic organisms, overall water quality, reduction in soil health, and increase in greenhouse gasses from anaerobic microbial degradation activities. Recent Findings: Current treatment technologies involve the use of combined chemical, biological, and physical approaches, which has been proven very effective. Another useful alternative is to utilize the high organic content present in the waste as substrate for the metabolism of microbes as catalyst in industrial processes including water treatment as well as production of useful microbial secondary metabolites such as pigments. Summary: This review highlights some example for the microbial biotransformation and biomineralization of organic-rich industrial discharges. This is important based on its potential to be applied as useful alternative techniques to dispose huge volumes of industrial waste as well as reducing high cost of sustaining biological-based industrial processes that would require substantial investment notably for the microbial growth medium. Nevertheless, clear insight into the engineering aspects of such processes and sufficient knowledge on its feasibility to function properly at pilot-scale level are of paramount importance prior to any commercialization attempts

Health effects of herbicides and its current removal strategies

ABSTRACTThe continually expanding global population has necessitated increased food supply production. Thus, agricultural intensification has been required to keep up with food supply demand, resulting in a sharp rise in pesticide use. The pesticide aids in the prevention of potential losses caused by pests, plant pathogens, and weeds, but excessive use over time has accumulated its occurrence in the environment and subsequently rendered it one of the emerging contaminants of concern. This review highlights the sources and classification of herbicides and their fate in the environment, with a special focus on the effects on human health and methods to remove herbicides. The human health impacts discussion was in relation to toxic effects, cell disruption, carcinogenic impacts, negative fertility effects, and neurological impacts. The removal treatments described herein include physicochemical, biological, and chemical treatment approaches, and advanced oxidation processes (AOPs). Also, alternative, green, and sustainable treatment options were discussed to shed insight into effective treatment technologies for herbicides. To conclude, this review serves as a stepping stone to a better environment with herbicides