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Lead (Pb²⁺) contamination in wastewater is a major environmental concern due to its toxicity, persistence, and ability to accumulate in living organisms. Adsorption using biomass-based materials has been developed as an alternative treatment method because it is efficient, economical, and environmentally friendly. This study aimed to analyze the effect of bioadsorbent dosage and contact time on Pb²⁺ removal efficiency and evaluate Pb²⁺ mass distribution using mass balance analysis in a batch adsorption system. Ramie leaf (Boehmeria nivea) was utilized as a bioadsorbent due to its lignocellulosic content, which provides active sites for metal ion adsorption. The research was conducted experimentally through bioadsorbent preparation, chemical activation, and batch adsorption using artificial Pb²⁺ solutions with variations in bioadsorbent dosage and contact time. Pb²⁺ concentrations before and after adsorption were analyzed using Atomic Absorption Spectroscopy (AAS). The obtained data were used to determine removal efficiency and Pb²⁺ distribution between the liquid phase and bioadsorbent. The results showed that ramie leaf bioadsorbent effectively reduced Pb²⁺ concentration, with the optimum condition obtained at 4 g/L bioadsorbent dosage and 90 minutes contact time, achieving 98.46% removal efficiency. Mass balance analysis indicated that Pb²⁺ ions were successfully transferred from the solution phase onto the bioadsorbent surface. These findings demonstrate that ramie leaf bioadsorbent has potential as a sustainable alternative material for heavy metal removal in wastewater treatment.

Lead (Pb²⁺) is a hazardous heavy metal commonly found in industrial wastewater and poses serious risks to human health and the environment due to its toxic and non-biodegradable nature. Therefore, an effective and environmentally friendly treatment method is required to reduce Pb²⁺ concentration in wastewater. This study aimed to evaluate the effect of pH and initial Pb²⁺ concentration on the adsorption capacity of ramie leaf (Boehmeria nivea) bioadsorbent activated with NaOH. The adsorption process was conducted using a batch system with pH variations of 4, 5, and 7 and initial Pb²⁺ concentrations of 20, 25, and 30 mg/L. The residual Pb²⁺ concentration was analyzed using Atomic Absorption Spectrophotometry (AAS), and the adsorption performance was evaluated based on removal efficiency and adsorption capacity (Qe). The results showed that pH and initial Pb²⁺ concentration significantly affected the adsorption performance. The optimum adsorption condition was obtained at pH 5, with a maximum removal efficiency of 99.20% and a total adsorption capacity of 18.56 mg/g. The increase in pH from 4 to 5 enhanced adsorption performance due to reduced competition between H⁺ and Pb²⁺ ions for active sites on the adsorbent surface. Increasing the initial Pb²⁺ concentration tended to increase adsorption capacity, although removal efficiency remained relatively stable due to the limited number of active adsorption sites. The Relative Standard Deviation (RSD) values ranged from 1.56% to 3.37%, indicating good precision and repeatability of the experimental data. These findings demonstrate that NaOH-activated ramie leaves have considerable potential as an effective, low-cost, and environmentally friendly bioadsorbent for Pb²⁺ removal from wastewater.

Chili (Capsicum annuum L) ) is one of the most important horticultural commodities widely consumed in Indonesia and has high economic value. To maintain productivity and prevent pest attacks, farmers commonly apply chemical pesticides intensively. However, excessive and improper pesticide application can leave harmful residues on the surface and within the tissues of chili fruits. The accumulation of these residues not only poses health risks to consumers but also contributes to environmental pollution, particularly in wastewater generated from chili washing activities. This study aims to reduce pesticide residues of Cherizeb and Emacel in chili washing water using the photolysis methodassisted by a ZnO/zeolite catalyst. Zinc oxide (ZnO) acts as a photocatalyst activated by ultraviolet (UV) light to produce reactive hydroxyl radicals (•OH) capable of decomposing complex organic compounds into simpler compounds such as CO₂ and H₂O. Meanwhile, zeolite is used as a catalyst support due to its large surface area and high adsorption capacity, allowing adsorption and photocatalytic processes to occur simultaneously. The results showed that the photolysis method using the ZnO/zeolite catalyst significantly reduced pesticide residues, with optimum degradation efficiencies of 85.66% for Cherizeb using 0.8 g ZnO/zeolite under UV irradiation for 60 minutes, and 83.97% for Emacel using 0.8 g ZnO/zeolite under UV irradiation for 75 minutes. The samples were characterized using Fourier Transform Infrared Spectroscopy (FTIR) to identify functional groups, indicating the disappearance of specific organic functional groups. Pesticide residues on chili samples were analyzed using UV-Vis spectrophotometry to determine concentrations before and after treatment. X-Ray Diffraction (XRD) analysis confirmed that the crystalline structure of the catalyst remained stable after the photolysis process. Based on these findings, the ZnO/zeolite catalyst is proven to be effective in reducing pesticide residues through photocatalytic degradation and has the potential to be applied as a safe, efficient, and environmentally friendly post-harvest technology to improve the quality of agricultural products.

Human activities, from household to industrial operations, generate liquid waste that poses a threat to the environment. Before discharge, liquid waste should be treated to ensure it is safe for release into the environment. This study aims to evaluate the effectiveness of a hybrid ozonation-adsorption method with varying contact times. This study collected leachate samples from the Rajabasa Landfill and used fly ash from the Tarahan Coal-Fired Power Plant as the adsorbent. First, the study used contact times of 20, 40, 60, and 80 minutes for ozonation. Subsequently, the 80-minute sample proceeded to the adsorption stage and was ultimately tested against six parameters. The measured parameters included COD, TSS, TDS, turbidity, UV254, and DO. The results showed that the 80-minute ozonation process significantly reduced TSS, TDS, and DO levels. However, the ozonation process still left intermediate compounds, which were subsequently removed by adsorption. Ultimately, the combination of the two processes yields good results, particularly for COD and UV254. This aligns with the theory that ozonation breaks down complex compounds while the adsorbent absorbs residual pollutants. This hybrid process achieves a 45.47% reduction in COD and an 87.83% reduction in UV254.

Acid mine drainage (AMD) is characterized by low pH and high concentrations of heavy metals such as iron (Fe) and manganese (Mn) that exceed environmental quality standards, thus requiring effective treatment to prevent environmental pollution. This study aims to evaluate the ability of a mixture of activated carbon derived from pineapple leaves mixed with coal to increase pH and reduce Fe, Mn, and Total Suspended Solids (TSS) levels in acid mine drainage at PT Alreksa Bara Mitra. The process to make activated carbon involved preparation, carbonization, and activation processes on the pineapple leaves and coal separately. The following step is to mix but pineapple leaves and coal the has been activated. The treatment was conducted using an adsorption method with variations in adsorbent mass of 4 g, 8 g, and 12 g and a contact time of 30 minutes. The parameters analyzed included pH, Fe, Mn, and TSS before and after treatment, and the results were compared with the quality standards stipulated in Minister of Environment and Forestry Regulation No. 05/2022. The results showed that the characteristics of the activated carbon mixture met the SNI 06-3730-1995 standard. Increasing the adsorbent mass contributed to the rise in pH from 5.5 to near the acceptable range of 6–9 and significantly reduced Fe, Mn, and TSS concentrations below the permitted limits.The findings indicate that the mixture of pineapple leaf- and coal-based activated carbon is an effective, economical, and environmentally friendly alternative adsorbent for acid mine drainage treatment.

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.

This study explores the innovative use of chitosan from shellfish and natural cellulose as an additive to decrease the viscosity of used lubricating oils. We synthesized and applied chitosan and cellulose as adsorbents to filter impurities and enhance the rheological properties of the oil. During the experiment, different amounts of chitosan and cellulose were used, and the Ostwald method was used to measure the viscosity. As expected, adding more chitosan (20 grams) made the viscosity much better compared to mixes with cellulose. This led to a viscosity of 658.20 cP, while a 15:5 chitosan-to-cellulose ratio made the viscosity the lowest, at 513.06 cP. FTIR analyses confirmed the structural integrity of chitosan post-synthesis. Challenges in optimizing chitosan production, particularly in achieving standard deacetylation levels, were noted as potential limitations. The results suggest that using biopolymers like chitosan and cellulose together is a long-term way to improve oil recovery and reuse, lower waste, and make industrial uses better. In the future, researchers should concentrate on enhancing the manufacturing process of chitosan to enhance its adsorption capabilities, and explore alternative functional modifications that could enhance its utility in a wider range of scenarios

Coal mining activities often result in acid mine drainage (AMD), which can cause environmental pollution if not properly managed. This study aims to evaluate the potential use of fly ash from the Stream Power Plant (PLTU) Tenggarong to mitigate the impacts of AMD, specifically targeting iron (Fe), manganese (Mn), and pH parameters. Acid Mine drainage is formed when sulfide minerals oxidize, producing acidic compounds that can harm the environment. This research focuses on analyzing the ability of fly ash to adsorb iron and manganese from AMD solutions, as well its capability to increase solution pH. Based on the conducted research, the optimum pH value was achieved when using 10 grams and 15 grams of fly ash in the adsorption process. The optimum concentration of iron (Fe) was attained using 10 grams to 15 grams of fly ash, while for manganese (Mn), it was achieved with 20 grams to 25 grams of fly ash. The adsorption process using 25 grams of fly ash showed the highest efficiency in reducing iron (Fe) concentration by 93.78 % and manganese (Mn) concentration by 75.47 %.

Adsorption is a separation process on a particular substance based on the affinity of a compound to a solid. The adsorption process requires an adsorbent as an absorbent material and an adsorbate as an absorbed component. The adsorbent that is often used to absorb Cu2+ ions is silica gel. Silica gel is a rigid gel that is amorphous. In silica gel there are two main bonding groups, namely siloxane and silanol groups which cause silica gel to easily absorb polar molecules, especially water. The purpose of this research is to get the best mass of silica and the effect of the initial concentration of Cu ions on the final concentration of Cu metal. In this study, two operating conditions were varied, namely the mass of silica gel adsorbent 0.4 grams; 0.6 grams; 0.8 grams; 1 gram; 1.2 grams and the initial concentration of Cu metal 3 ppm; 4 ppm; 5 ppm; 6 ppm; 7 ppm. The results of this study showed that the silica content of bagasse ash was 70.97% with a surface area of 283.802 m2/g. The best result of this study reduced the content of copper metal (Cu) by 88% in the condition of silica gel mass of 1.2 grams. The adsorption isotherm shows that the data is more in line with the Freundlich equation. The resulting equation is y = 0.4268x + 0.4969 with an R2 value of 0.9837.