Papers by Keyword: Wastewater

Abstract: Industrial wastewater often contains colored toxic dyes and heavy metals that harm ecosystems and human health, highlighting the need for sustainable treatment strategies. This study aimed to develop a guar gum (GG)/polyacrylamide (PAAm)/rice straw biochar (RSBC) hydrogel grafted onto polyethylene terephthalate (PET) (GG/PAAm RSBC-g-PET) textile, and its structure was characterized through swelling behavior, FTIR-ATR spectroscopy, and Scanning Electron Microscopy (SEM) analysis. The modified GG/PAAm/RSBC-g-PET exhibits a significant increase in water absorption compared to GG/PAAm-g-PET. The alteration and shifted peaks were observed particularly at bands of 3441 cm^-1 (RSBC), and 852 cm^-1 (galactose and mannose units), imparting effective crosslinking. SEM analysis revealed a porous structure with irregular magnetite particles, enhancing the active surface area. The performance of the GG/PAAm/RSBC-g-PET composite was evaluated using industrial wastewater, which resulted in reduced turbidity (26.5 NTU) and color (~49.5 ADMI), compared to filtration with PET textile alone (47 NTU and ~69.5 ADMI). The GG/PAAm/RSBC-g-PET composite exhibits comparable yet inconsistent improvements, possibly due to particle release and pore blockage. These findings demonstrate the feasibility of the GG/PAAm/RSBC-g-PET textile for decolorization, indicating its potential application in wastewater remediation.

Abstract: Theoretical and experimental investigations have revealed significant spatial variations in the chemical element content of wastewater, primarily due to anthropogenic pressures from mining and industrial complexes. This indicates the diverse nature of pollution sources and the complex impact they exert. The most pronounced exceedances of permissible concentrations were observed for manganese, potassium, magnesium, and calcium, attributed to the leaching of elements from rock dumps and chemical weathering processes. Analysis of the total pollution index (Zc) helped identify areas with high levels of technogenic impact, necessitating urgent environmental protection and reclamation measures. Spatial models illustrating element distribution demonstrate a direct correlation between toxicant concentrations in aquatic environments and the location of technogenic objects, particularly spoil heaps. The findings are crucial for future planning of environmental protection initiatives in mining and industrial regions. They enable the identification of areas with the highest ecotoxicological burden and will be utilized for environmental monitoring of water bodies, forecasting ecological risks, and establishing a database for decision-making regarding reclamation and water resource quality management.

Abstract: Antimicrobial resistance (AMR) is a global health crisis that undermines the effectiveness of antibiotics in treating infections, posing a threat to humans and animals. Antibiotics are not fully metabolized by humans or animals, leading to their dispersion within sewage streams. The dissemination of antibiotic-resistant bacteria in aquatic environments poses a significant public health risk, particularly through the release of treated wastewater into natural water bodies. This study investigated the presence of Antibiotic Resistance Genes (ARGs) in Klebsiella sp. isolates collected from four sampling points along the Wupa River and its wastewater treatment plant (WWTP): Upstream (P1), Influent (P2), Effluent (P3), and Downstream (P4). Physicochemical analyses of water samples showed that most parameters, including temperature, pH, total dissolved solids, dissolved oxygen, and nitrates, stayed within WHO-recommended limits. However, phosphates, total suspended solids, and ammoniacal nitrogen consistently exceeded these limits at all sites. The highest levels of biochemical oxygen demand (BOD), soluble chemical oxygen demand (COD), and total COD were found at the influent. The Total Viable Count carried out for bacterial colonies and Klebsiella colonies to assess microbial load showed the highest value at the 10^ (- 2) dilution factor and the lowest at the 10^ (- 5) dilution factor. Isolation and identification of Klebsiella spp. were performed using biochemical tests, including Voges-Proskauer (+), Indole (-), Citrate (+), Urease (+), Methyl red (-), Triple Sugar Agar (+), and Gram staining, revealing Gram-negative rods. Molecular analysis detected amplification of key resistance genes sul2, tetB, blaTEM, and blaCTX. Amplification of tetB gene in both influent and effluent samples indicates incomplete removal of tetracycline resistance genes during wastewater treatment. The blaTEM and blaCTX genes were detected across all sampling points, suggesting widespread environmental dissemination and potential contamination sources beyond the WWTP. These findings highlight the persistence and spread of multidrug-resistant Klebsiella in riverine and wastewater environments, underscoring the critical need for improved wastewater treatment strategies and continuous monitoring to mitigate the public health impact of antibiotic resistance in aquatic ecosystems.

Abstract: Nanostructured titanium dioxide (TiO₂) was synthesized via a hydrothermal method to enhance photocatalytic degradation of organic and pharmaceutical contaminants in wastewater. Characterization techniques confirmed the formation of anatase-phase TiO₂ with a tetragonal structure, spherical morphology, and an average crystallite size of 29 nm. The material exhibited a band gap of 3.1 eV. The TiO₂ solution has proven to be very effective in accelerating the breakdown of pharmaceutical and organic contaminants in wastewater, as evidenced by several methods, including high-performance liquid chromatography (HPLC) and Gas chromatography (GC). Photocatalytic performance was evaluated under varying catalyst concentrations and pH levels. Optimal degradation efficiency (72%) was achieved at pH 10, demonstrating TiO₂'s potential as an effective photocatalyst for wastewater treatment.

Abstract: The use of aluminum oxide nanoparticles (Al-NPs) in wastewater treatment has emerged as a promising approach due to their unique physicochemical properties, including a high surface area, strong adsorption capabilities, and effective adsorbent performance. This study investigates the use of Al-NPs for the removal of chemical oxygen demand (COD) from synthetic aqueous solutions. COD is one of the main indicators of water pollution and can be used to assess water quality. The characterization of Al-NPs was conducted using various techniques, including X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray (EDX), and the Brunauer-Emmett-Teller (BET) technique. XRD analysis confirmed the successful synthesis of Al-NPs with a well-defined crystalline structure and desirable crystallite size. The data correlated with TEM findings, validating the nanoscale properties of the Al-NPs. The EDX spectrum showed prominent peaks corresponding to aluminum (Al) and oxygen (O), indicating the presence of Al and possibly Al₂O₃. A higher BET surface area typically correlates with improved pollutant adsorption performance, as more surface sites are available for interaction. Adsorption data were analyzed using the Freundlich isotherm model, which suggested a heterogeneous adsorption surface, and the pseudo-second-order kinetic model, indicating that the adsorption mechanism was predominantly chemisorption. These findings highlight the potential of Al-NPs as effective adsorbents for pollutant removal from wastewater, with implications for optimizing treatment processes in industrial and domestic applications. The maximum removal efficiencies (R%) for chemical oxygen demand (COD), phosphate (PO₄), and total suspended solids (TSS) were 97.04%, 42.62%, and 98.63%, respectively. The highest removal efficiency was achieved at an Al-NP dosage of 120 mg/L. These findings demonstrate that Al-NPs can be effectively used as coagulants in wastewater treatment.

Abstract: The increasing concentrations of heavy metals (HM) in the water bodies, primarily caused by the rapid use of fertilizers in farming and increasing industrialization, pose a serious threat to the deteriorating earth’s environment and human health. This pollution is dangerous to water-dwelling life forms and is also of concern because it is believed to be a carcinogen. To overcome these challenges, constant water quality analysis must be done. Out of all the remediation methods, the adsorption-based techniques are considered one of the most suitable means of addressing the problem of heavy metal toxicity in wastewater. The latest trends in the application of Functionalized Magnetic Nanomaterials (MNPs) attached to nanocomposites, including carbon-based materials like carbon nanotubes (CNTs), Graphene Oxide (GOx), and Graphene Quantum Dots (GQDs) and inorganic supports like Zeolites (ZLs) and Metal-Organic Frameworks (MOFs), demonstrate high efficiency in the extraction of heavy metals (HM). These nanocomposites possess a higher rate of active surface area and can adsorb properties, which make them reusable over multiple cycles of treatment in various forms of wastewater. This review will discuss the preparation method of engineering MNPs on CNTS and GOx and analyze modern materials' role in removing heavy metals. Besides, due to the observed effects of the substances on the biota, the study will highlight the need to conduct more research on the ecotoxicological effects of the materials and design suitable methods that can guarantee the effectiveness of the materials in promoting a sustainable environment.

Abstract: Integrated water management aims to promote water supply from conventional resources and wastewater reuse to address issues such as water scarcity. The positive input from collecting and reusing water for household purposes has not often seen assessments of the impact of climatic change, water resource availability, and water deprivation in various regions. If the water resource comes from a clean water resource and was first used to wash or bathe, it is commonly referred to as greywater. GW is an abundant resource generated throughout people's daily lives. GW can be used for domestic cleaning, flushing toilets, washing vehicles, washing kitchen gardens, washing clothes, and washing before rinsing. This research study aims to develop an experimental system for GW treatment with the optimum cost and reuse it in landscape facilities. The main result showed achieving a suitable design for GW, which improves the water's characteristics and quality so that it is suitable for use in landscaping agriculture, at a total cost of 15.6 $ to effluent discharge water amount of 1.75 m³/h. This study showed that the presented experimental study, which uses a conventional treatment process built with existing systems, can achieve satisfactory results of GW treatment. The turbidity was reduced with an effectiveness rate of 96% and a filtration efficiency of 96.5% for TSS, particularly in filtration by a mixture of screen filter and gravel filter.

Abstract: In this study, silica (Si) nanoparticles derived from rice husk ash is coated with cetyltrimethylammonium bromide (CTAB), a cationic surfactant, and used as adsorbent of nitrate ion in wastewater. CTAB functionalized Si (CTAB-Si) nanoparticles were characterized using scanning electron microscope (SEM), energy dispersive X-Ray (EDX), dynamic light scattering (DLS) Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The synthesized CTAB-Si nanoparticles has a non-spherical shape, with visible polydispersity and is amorphous with average particle size of 72nm. It showed stretching vibrations of silanol at 963cm^-1, siloxane at 1073cm^-1, sharp peaks at 2852cm^-1 and 2922cm^-1 due to the methylene tail of CTAB and amine peak at 1,384cm^-1. An ∼80% nitrate removal and adsorption capacity of 7.98 mg NO₃/g CTAB-Si nanoparticles was obtained at optimized condition using Face Centered Central Composite Design (FC-CCD) at pH 4, 50 mgL^-1 of adsorbate concentration, 0.2 gL^-1 adsorbent dose and 30 minutes contact time. The adsorption isotherm and kinetic models fits well in Langmuir model and Pseudo second order with a R² of 0.984 and 0.999 respectively. The efficiency of the nanoparticle after 5 adsorption cycles was ∼50% nitrate removal.

Abstract: In this study, Volvariella vovacea (straw mushroom, SM) and Flammulina velutipes (Golden mushroom, GM) were used as a natural source of chitin. The aim of this research is to extract chitin and thus, converted into chitosan via acetylation process. The obtained chitosan was applied in the wastewater treatment process as the coagulant to improve the quality of wastewater. As these two types of mushrooms are readily available in the local area in Northeastern Thailand and relatively cheap. The chitin extraction process was obtained by firstly removing fat, minerals, protein and pigment of SM and GM using petroleum ether, HCl, NaOH and acetone respectively. Extracted chitin was deacetylated by using 50% (v/v) NaOH at 140 ^oC for 2 hours to convert into chitosan. The properties of extracted chitosan was examined by FT-IR and TGA. FTIR spectrum showed the peaks of C-H stretching at 2870 cm^-1 , N-H₂ bending at 1586 cm^-1, N-H stretching at 1026 cm^-1, etc. which corresponded to the standard chitosan. TGA showed the thermal decomposition which is divided into three phases. First stage of weight loss is between 50-115 °C caused by water evaporation. There was no changes of weight during a temperature of 115-268 °C. The second phase during 268-330 °C indicates a significant weight loss which is due tot he saccharide degradation of chitosan and at a temperature more than 330°C refers to the volatile organic material. As a result of TGA, it can be confirmed that the extracted chitosan from SM and GM is very similar to the standard commercial chitosan. After that, 3 g of extracted chitosan was mixed with 300 mL of deionized water and 6 mL of acetic acid was added for 24 hours to prepare the chitosan coagulant. Then, it was dropped in the separate jar which contained high TSS, COD and BOD wastewater. The results showed that chitosan biocoagulant could reduce TSS, COD and BOD by 62, 62 and 88% respectively which proved to be efficient in the use of wastewater treatment.

Abstract: Conventional wastewater treatment technologies have been extensively studied for degrading organic matter, suspended solids, nutrient removal, and lowering microbial loads. They produce acceptable-quality effluent, but researchers have reported several limitations. Recently, advanced wastewater treatment technologies have preceded as an alternative to the degradation of recalcitrant wastes such as persistent organic compounds (POPs), pharmaceutically active compounds (PhACs), contaminants of emerging concern (CECs), and heavy metals (H.M). They can be physical, chemical, biological, or integration between one or more technologies. This is to meet the requirements for reuse for different purposes, minimize or prevent the negative impacts on the environment, and create new untraditional water resources to solve the water shortage problem. This article is a collected review of advanced wastewater treatment technologies. Also, the applications of these technologies with special concern for partially/hardly degradable pollutants from wastewater are indicated. They are eco-friendly, cost-effective, low-energy systems with a small footprint. Their selection depends on the characterization of wastewater, biodegradability, available footprint, quality of treated effluent required, cost, availability of funds, and personal skills.