Tropical Aquatic and Soil Pollution

Environmental Impact and Decompsition of Polycyclic Aromatic Hydrocarbons (PAHs) in Urban Soils: Challenges and Future Directions

2024-10-28T01:19:19+00:00

The rapid pace of urbanization and development has led to an increasing global concern over polycyclic aromatic hydrocarbons (PAHs) due to their persistent and widespread presence in the environment, posing significant threats to ecosystems and human health. PAHs originate from both natural and human-made sources and can be categorized based on their origin into pyrogenic, petrogenic, and biogenic products. Upon entering the environment, PAHs undergo various chemical and biological transformations, and their movement occurs through processes such as air-to-soil and soil-to-air transport. Composting, a green and cost-effective technology, offers a promising solution for PAH remediation. This process, which includes mesophilic, thermophilic, cooling, and maturing stages, can yield compost that is useful as fertilizer and soil amendment in agriculture. The success of composting depends on factors such as substrate bioavailability, oxygen levels, nutrient supply, and environmental conditions. While composting has shown effectiveness in reducing PAH levels, it is not without challenges, including the risk of weed infestation, greenhouse gas emissions, and odor pollution. The main obstacles in PAH remediation today are the limited bioaccessibility of PAHs and the insufficient focus on the formation of oxygenated PAHs during the process. Future research should address these challenges, particularly by improving PAH bioaccessibility and mitigating issues related to odor and greenhouse gas emissions.

Environmental Impact of Synthetic Dyes on Groundwater in Malaysia: Sources, Distribution, Transport Mechanisms, and Mitigation Strategies

2024-10-20T09:10:05+00:00

Synthetic dyes, extracted from natural sources like insects, plants, coal, and ochre, have become prevalent due to their advantages over natural dyes. However, their production has led to increased environmental pollution, particularly in groundwater. Groundwater contamination from synthetic dyes occurs through advection, dispersion, and retardation. This review aims to highlight the environmental impacts of synthetic dyes on groundwater, elucidate the mechanisms of dye transport, and propose effective strategies for monitoring and mitigating contamination. Urban runoff carries dyes from surfaces such as roofs, parking lots, and roads into stormwater systems, while agricultural runoff transports dyes from products like soil conditioners, fertilizers, and seed coatings into water bodies. In groundwater, dyes move through the aquifer via advection, dispersion, and retardation, all influenced by groundwater flow and geological conditions. The advection process involves the bulk movement of groundwater carrying dissolved dyes, while dispersion causes dyes to spread and dilute over time and distance. Retardation, which involves the adsorption of dye molecules onto soil particles, slows dye movement, prolonging their presence in groundwater. Understanding the sources, distribution, and movement of synthetic dyes in groundwater is crucial for developing strategies to protect water resources and reduce environmental and health impacts. The extensive use of dyes in industrial and domestic activities necessitates comprehensive monitoring and management to ensure sustainable groundwater quality.

Endocrine-Disrupting Compounds in Urban Soils of Malaysia: Occurrence, Contamination, and Impacts on Health and the Environment

2024-10-20T09:10:03+00:00

Endocrine-disrupting compounds (EDCs) have garnered increasing concern in recent years due to their association with severe health issues and significant environmental impacts. EDCs, which can interfere with endogenous hormone systems, are diverse in structure and are often characterized by low molecular mass and halogen substitutions. Their presence in the environment, originating from both natural and synthetic sources, has been well-documented in water bodies, but studies on their occurrence in soils remain limited. This review provides a comprehensive overview of the occurrence, contamination, and impacts of EDCs in the urban soils of Malaysia. The paper discusses the primary sources of EDCs, including pharmaceuticals, pesticides, industrial chemicals, and combustion byproducts, and examines the pathways through which these compounds enter the soil. Health risks associated with exposure to EDCs, as well as their ecological consequences, are also explored. The review highlights the current status of EDCs contamination in Malaysian soils, identifies gaps in research, and outlines the challenges in monitoring and mitigating these contaminants. Understanding the dynamics of EDCs in soil is crucial for developing effective strategies to protect human health and the environment in urban settings.

Synthesis of Aluminum Oxide Nanoparticle Adsorbents from Waste Aluminum Foil and Assesses Their Efficiency in Removing Lead (II) Ions from Water

2024-11-15T14:28:25+00:00

Aluminum oxide nanoparticles have recently been applied to water treatment as adsorbents by researchers. In this study, aluminum oxide nanoparticles (AlONPs) were synthesized using scrap aluminum foil through a straightforward, inexpensive, and green approach, and their performance in adsorbing lead (II) ions from an aqueous solution was assessed. The synthesized nanoparticles were characterized using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (SEM-EDX) to analyze their bonding nature, particle size, phase composition, and surface morphology. They exhibited an average particle size of 32.73 nm, consisting predominantly of γ-Al₂O₃, with small amounts of α-Al₂O₃ and a minor unknown phase. The lead adsorption efficiency was evaluated under optimized parameters, including pH, contact time, and doses of both adsorbate and adsorbent. The results demonstrated that the AlONPs achieved a 98% removal efficiency within 30 minutes of contact time at a pH of 5.5. Additionally, the Freundlich adsorption isotherm model (R² value of 0.9972) and the pseudo-second-order kinetic model (q_e) value of 37.97 mg/g) were shown to fit the lead adsorption process better than other models. Hence, the synthesized AlONPs offer potential as nanoparticle adsorbents for removing lead (II) ions from aqueous solutions.

Phytoremediation of Palm Oil Mill Effluent (POME) Using Water Lettuce and Duckweed

2024-08-16T06:34:32+00:00

Phytoremediation is a widely recent studied and applied technology, using various plants to remediate contaminants from wastewater by extraction, containment or destruction method which also known as eco-friendly and cost-effective techniques compared to conventional processes. The huge increased of palm oil production industry has become major environmental concern but not much have been said about the negative effects. Three major waste streams in processing palm oil were gaseous (pollutant gases), liquid (POME) and solid (palm press fibre, chaff, palm kernel shell and empty fruit bunch). The aim of this study was to determine the potential of water lettuce (Pistia stratiotes) and duckweed (Lemna minor) in removing contaminants in POME. Seven water quality parameters based on Sewage and Industrial Effluent Discharge Standards were selected in this study like pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammoniacal nitrogen (NH₃-N), iron (Fe) and zinc (Zn). POME sample were placed in 3 basins for 28 days; (basin 1 – control, basin 2 – duckweed, Basin 3 – water lettuce), and each basin were tested with different retention time. The results showed that both studied plants have positive result as phytoremediation agents effectively in removing contaminants of POME. To achieve optimal contaminant reduction, incorporate a combination of phytoremediation and other complementary treatment would be beneficial before POME release into waterways.