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The danger of cadmium contamination in water sources remains a crucial environmental issue due to its persistent nature and high toxicity level, which poses serious risks to human health and ecosystems. Cadmium is a non-biodegradable heavy metal that can accumulate in living organisms over time. The presence of these toxic Cd²⁺ ions is known to trigger damage to vital organs such as the liver and kidneys; therefore, reducing their concentration in aquatic environments is of paramount importance for environmental protection and public health safety. Among various treatment methods, adsorption is considered one of the most effective and economical techniques for removing heavy metal ions from contaminated water. In this study, the capability of mesoporous silica MCM-48-NH₂ as an adsorbent for Cd²⁺ ions was systematically evaluated. The adsorption performance was examined by investigating several important parameters, including contact time, solution acidity level (pH), and initial Cd²⁺ concentration. Furthermore, the adsorption mechanism and interaction between Cd²⁺ ions and the adsorbent surface were analyzed using Langmuir and Freundlich isotherm models. The results demonstrate that the adsorption process of Cd²⁺ ions onto MCM-48-NH₂ tends to follow the Langmuir isotherm model, indicating monolayer adsorption behavior, with a maximum adsorption capacity of 0.66 mmol g⁻¹.

Zinc (Zn) is one of the most common heavy metal contaminants found in industrial wastewater and solid residues such as slag, electroplating waste, and metal ash. At excessive concentrations, Zn can cause environmental disturbances, including toxicity to aquatic organisms, disruption of microbial activity, and groundwater contamination. Long-term exposure may also lead to bioaccumulation and potential health risks to humans. This article presents a comprehensive literature review that discusses the chemical properties of Zn, its environmental behavior, and the development of recent treatment technologies within the last five years. Several techniques, including adsorption using modified or composite materials, biosorption utilizing microalgae and agricultural biomass, as well as solidification–stabilization with amendment agents such as biochar or iron-sulfide compounds, are evaluated and compared. The literature indicates that no single treatment method is universally effective for all waste types; therefore, hybrid or integrated treatment systems are considered more efficient and sustainable. Based on the reviewed evidence, this study proposes an engineering concept that emphasizes environmental safety, cost-effectiveness, and industrial applicability.

Acid mine drainage (AMD) is one of the major environmental problems arising from coal mining activities. AMD is formed through the oxidation of sulfide minerals, resulting in acidic water with high concentrations of dissolved heavy metals. This condition is characterized by elevated levels of Fe, Mn, and total suspended solids (TSS), which, if left untreated, can pollute nearby water bodies, damage aquatic ecosystems, and pose risks to human health. Therefore, effective, eco-friendly, and low-cost treatment methods are needed to minimize the negative impacts of AMD. This study aims to investigate the effect of activated carbon derived from sugarcane bagasse as an adsorbent for reducing Fe, Mn, and TSS levels in AMD at the sump of PT Alreksa Bara Mitra. The selection of sugarcane bagasse is based on its abundance as an agro-industrial waste and its high lignocellulosic content, making it a potential raw material for activated carbon. The research involved the preparation of activated carbon through carbonization and activation processes, followed by its application to AMD samples with variations in adsorbent dosage and contact time. Laboratory analyses were conducted to measure the concentrations of Fe, Mn, and TSS before and after treatment. The results showed that sugarcane bagasse-based activated carbon significantly reduced Fe, Mn, and TSS concentrations. The highest removal efficiencies were achieved under optimum conditions, reaching 93.14% for Fe, 95.05% for Mn, and 85.04% for TSS. These findings demonstrate that activated carbon from sugarcane bagasse has a strong adsorption capacity for dissolved metals and suspended solids in AMD. In conclusion, sugarcane bagasse-derived activated carbon has potential as an environmentally friendly and cost-effective alternative for AMD treatment, while simultaneously providing added value to agro-industrial waste. This research is expected to serve as a reference for the development of more sustainable mine wastewater treatment methods.

This study investigates the corrosion inhibition potential of a newly synthesized organic compound, (E)-4-hydroxy-3-(phenylamino)pent-3-en-2-one (LASA3), using computational chemistry approaches. Density Functional Theory (DFT) calculations were performed at the B3LYP/6-31G(d) level of theory with the Gaussian09 software package to evaluate several key quantum chemical parameters. These parameters include total energy, the energies of the highest occupied molecular orbital (EHOMO) and lowest unoccupied molecular orbital (ELUMO), the energy gap (ΔEgap), dipole moment, chemical hardness, softness (σ), and the number of electrons transferred (ΔN). The computational results reveal that LASA3 exhibits a higher EHOMO value and a smaller ΔEgap compared to its precursor molecules, referred to as S.M.1 and S.M.2. A higher EHOMO value suggests that LASA3 has a greater electron-donating ability, which enhances its interaction with the metal surface. Likewise, the reduced ΔEgap indicates greater chemical reactivity and a higher likelihood of forming stable coordination bonds with iron atoms on the carbon steel surface. Electrostatic potential (ESP) map analysis further supports these findings by highlighting the distribution of electron density within the LASA3 molecule. The ESP maps show significant electron-rich regions localized around nitrogen and oxygen atoms, which are potential active sites for adsorption onto the steel surface. This adsorption process plays a crucial role in blocking active corrosion sites and reducing the rate of metal degradation. In conclusion, the theoretical analysis confirms that LASA3 has superior electronic properties for corrosion inhibition compared to its starting materials, S.M.1 and S.M.2. Its ability to donate electrons, favorable dipole characteristics, and strategically located electron-rich sites make it a promising candidate for further experimental evaluation as an efficient corrosion inhibitor for carbon steel applications.  

The pharmaceutical industry produces solid, liquid, and gaseous waste containing active pharmaceutical ingredients that pose serious environmental risks. These wastes can disrupt ecosystems and accelerate antimicrobial resistance. This systematic literature review examines pharmaceutical waste concepts, classifications, characteristics, and relevant regulatory frameworks. It also addresses ecotoxicological effects on aquatic and terrestrial ecosystems, antibiotic contamination and resistance, water and soil pollution, treatment technologies, industrial policies, and best practices. Findings show that conventional wastewater treatment is largely ineffective at removing pharmaceutical residues, resulting in their presence in surface water, soil, and even drinking water. Compounds such as β-blockers, cytostatics, antibiotics, and hormones harm aquatic life by impairing reproduction and causing mutations. Antibiotic-laden industrial waste contributes to the emergence of resistant bacteria. Recommended treatment methods include biothermal processes, advanced oxidation (e.g., UV/H₂O₂, ozonation), adsorption (activated carbon), coagulation-flocculation, and controlled incineration. Stronger enforcement of hazardous waste regulations (e.g., Government Regulation No. 101/2014, Ministry of Environment and Forestry Regulation No. 56/2015) and adherence to WHO (2025) guidelines are essential. In conclusion, multisectoral collaboration (One Health), improved waste treatment capacity, and adoption of best practices are crucial to preventing pharmaceutical pollution and promoting environmental sustainability.

The use of Cr (Chromium) in industry and daily life produces toxic waste harmful to humans and the environment. This study aims to evaluate the effectiveness of activated carbon from corn cobs as an adsorbent for Cr(VI) heavy metal. Corn cobs, which contain 40–44% cellulose, were carbonized at 500°C using 6% sodium carbonate and characterized with an IR spectrophotometer. Adsorption tests were conducted by varying pH and contact time to determine optimal conditions. FTIR results revealed functional groups such as C≡C stretch, C=C=C stretch, and C–O bend. After activation, O–H groups appeared, indicating the presence of aromatic compounds, which are typical in activated carbon. The optimum pH for Cr(VI) adsorption was pH 4, with an adsorption rate of 65.35%. The optimum contact time was 60 minutes, resulting in 3.2% Cr(VI) adsorbed and a maximum adsorption capacity of 0.089 mg/g. In conclusion, corn cobs are a promising, eco-friendly, and effective natural material for adsorbing Cr(VI) heavy metal ions.

Coal is an organic mineral from ancient plant remains that settles and goes through physical or chemical processes over a period of up to millions of years. Coal is used as a source of steam-powered electrical energy through combustion which produces fly ash waste. fly ash contains various chemical materials such as SiO2; Al2O3; Fe2O3. The potential chemical content makes fly ash which can be used as an adsorbent for heavy metals and dyes by forming silica xerogel. To increase the silica oxide content in fly ash, a washing process is carried out with various solvents. Research on the adsorption of methylene blue dye using silica xerogel from fly ash with variations in contact time. The results showed that silica xerogel from fly ash was able to adsorb methylene blue dye at a contact time of 90 minutes. Adsorption kinetics follows a pseudo second order model with an R2 value that is better than pseudo first order. It can be seen that the R2 value respectively shows a linear regression of 0.703 for pseudo first order and 1 for pseudo second order.

The utilization of clam shells as adsorbents has attracted considerable attention due to their ability to adsorb contaminants such as heavy metals, hazardous substances, and oil. Clam shells, which are composed mainly of calcium carbonate (CaCO₃), possess a porous structure that favors adsorption. Calcium carbonate imparts alkaline properties that neutralize acidic effluents and promote the formation of precipitates. Physical and chemical modifications can enhance the surface area and porosity of the shell, thereby enlarging the active sites for contaminant sorption. Clam shells heavy metals such as Pb, Cd, Hg, organic substances and can be used for oil spill remediation due to their hydrophobic and oleophilic properties. The calcination process converts the shells into a material that contaminants such as TSS, COD, and BOD. This utilization not only mitigates pollution but also creates opportunities for adsorbent products with economic value, especially in coastal areas where shell waste is abundant. However, this application must take into account ecological and health impacts, as overharvesting and non-environmentally friendly processing can damage the ecosystem. A sustainable approach with environmentally friendly regulations and technologies is essential to maximize the benefits of clam shells as adsorbents.  

One of the negative impacts of the mining process is acid mine drainage which is formed from the oxidation of minerals containing iron sulfur, such as pyrite (FeS2) and pyrothite (FeS) by oxidizers such as water and oxygen. To handle or control acid mine drainage, one way is to use activated carbon or often referred to as activated charcoal, which is a type of carbon that has a very large surface area. Charcoal is a porous solid that contains 85% to 95% carbon, produced from materials containing carbon by heating at high temperatures without oxygen (pyrolysis). Activated carbon made from palm shells is an adsorbent that can be used to treat coal mine acid water, so that the water meets standards for flowing into the environment. This study used concentration variants of 4 grams, 6 grams, 8 grams and contact times of 30 minutes, 60 minutes and 150 minutes. The results of this study show that the concentration of palm oil shell activated carbon adsorbent influences the reduction of iron (Fe) and manganese (Mn) metal levels as well as the pH conditions in acid mine drainage water. The higher the concentration and the longer the contact time, the more heavy metals are adsorbed, the contact time is the highest. The optimal concentration in this study was 150 minutes and the optimal concentration was 8 grams with physical activation.

Microplastic pollution, particularly from textile waste, has become a significant environmental concern, especially in urban runoff systems. These pollutants pose a considerable threat to water quality, aquatic life, and human health. Traditional wastewater treatment methods often fall short in addressing the complexities of microplastic contamination. This research explores the integration of advanced biodegradable polymer coatings with solar-powered textile waste treatment to reduce microplastic pollution in urban runoff systems. Biodegradable polymers, such as polylactic acid (PLA) and polyhydroxyalkanoates (PHA), are highlighted for their potential to efficiently filter microplastics while providing an eco-friendly alternative to conventional filtration technologies. By combining these materials with a small solar-powered unit, the prototype enables an off-grid, low-energy solution to treat textile wastewater in urban environments. The study includes testing the prototype in simulated urban runoff conditions with varying concentrations of microplastics, evaluating key performance indicators such as microplastic removal efficiency, energy consumption, and operational sustainability. Results demonstrate a significant reduction in microplastic concentration, indicating the effectiveness of biodegradable polymer coatings and solar-powered systems in treating urban runoff. The discussion addresses the feasibility of using local biodegradable materials, performance in real-world urban environments, and operational challenges such as maintenance and scalability. This innovative approach is compared with existing microplastic filtration methods, such as membrane filtration and adsorption, highlighting its advantages in terms of sustainability and cost-effectiveness. The findings suggest that this integrated system could offer a viable, low-cost solution for addressing microplastic pollution in urban drainage systems, with potential for widespread urban implementation.

Rice husk is a waste originating from agricultural waste that has not been utilized properly. The purpose of this study was to compare NaOH-activated rice husk activated charcoal with unactivated activated charcoal, and to measure the adsorption capacity of activated charcoal to methylene blue. Gravimetry, volumetry, and spectrophotometry are the analytical techniques used in this analysis. In this study, 1.5 M rice husk activated charcoal with NaOH showed the best results. It showed a water content of 8.81%, ash content of 5.87%, volatile matter content of 6.60%, and carbon content of 78.72%. In addition, the results showed that NaOH-activated rice husk activated charcoal has characteristic capabilities and adsorption capacity to methylene blue that meets SNI. The longer it is reasonable, the more rice husk activated charcoal.

Graphene is a two-dimensional lattice made of a single carbon atom and has extraordinary mechanical, electrical and thermal properties. These properties make it a very important material for a variety of applications, including energy management and electronics. This research adopts a systematic literature review approach to evaluate the role of graphene in improving battery performance and environmental sustainability. The results show that graphene significantly improves the performance of lithium-ion and lithium-sulfur batteries as well as sodium and magnesium-based batteries. In addition, graphene also has great potential for environmental applications such as water purification and pollutant adsorption. However, challenges such as production costs, toxicity, and scalability still need to be overcome for wider adoption.