The mechanisms of pH regulation on promoting volatile fatty acids production from kitchen waste.

The anaerobic acid production experiments were conducted with the pretreated kitchen waste under pH adjustment. The results showed that pH 8 was considered to be the most suitable condition for acid production, especially for the formation of acetic acid and propionic acid. The average value of total volatile fatty acid at pH 8 was 8814 mg COD/L, 1.5 times of that under blank condition. The average yield of acetic acid and propionic acid was 3302 mg COD/L and 2891 mg COD/L, respectively. The activities of key functional enzymes such as phosphotransacetylase, acetokinase, oxaloacetate transcarboxylase and succinyl-coA transferase were all enhanced. To further explore the regulatory mechanisms within the system, the distribution of microorganisms at different levels in the fermentation system was obtained by microbial sequencing, results indicating that the relative abundances of Clostridiales, Bacteroidales, Chloroflexi, Clostridium, Bacteroidetes and Propionibacteriales, which were great contributors for the hydrolysis and acidification, increased rapidly at pH 8 compared with the blank group. Besides, the proportion of genes encoding key enzymes was generally increased, which further verified the mechanism of hydrolytic acidification and acetic acid production of organic matter under pH regulation.

Soil colloids can significantly enhance spreading of polybromodiphenyl ethers in groundwater by serving as an effective carrier.

Polybromodiphenyl ethers (PBDEs), the widely used flame retardants, are common contaminants in surface soils at e-waste recycling sites. The association of PBDEs with soil colloids has been observed, indicating the potential risk to groundwater due to colloid-facilitated transport. However, the extent to which soil colloids may enhance the spreading of PBDEs in groundwater is largely unknown. Herein, we report the co-transport of decabromodiphenyl ester (BDE-209) and soil colloids in saturated porous media. The colloids released from a soil sample collected at an e-waste recycling site in Tianjin, China, contain high concentration of PBDEs, with BDE-209 being the most abundant conger (320 ± 30 mg/kg). The colloids exhibit relatively high mobility in saturated sand columns, under conditions commonly observed in groundwater environments. Notably, under all the tested conditions (i.e., varying flow velocity, pH, ionic species and ionic strength), the mass of eluted BDE-209 correlates linearly with that of eluted soil colloids, even though the mobility of the colloids varies markedly depending on the specific hydrodynamic and solution chemistry conditions involved. Additionally, the mass of BDE-209 retained in the columns also correlates strongly with the mass of retained colloids. Apparently, the PBDEs remain bound to soil colloids during transport in porous media. Findings in this study indicate that soil colloids may significantly promote the transport of PBDEs in groundwater by serving as an effective carrier. This might be the reason why the highly insoluble and adsorptive PBDEs are found in groundwater at some PBDE-contaminated sites.

Disinfection of Medical Solid Waste through the Application Ozone Technology: Feasibility and Effectiveness Study.

Background: We aimed to determine the feasibility of ozone for disinfection of infectious solid waste in hospital. Methods: Spores of Bacillus atrophaeus were used to monitor the process of inactivating microbial agents using ozone in medical solid waste in the hospitals of Tabriz City, Iran. For this purpose, culture medium containing the mentioned bacteria was placed in the bags containing medical wastes. The ozone generator was equipped with a constant dose of 5 grams per liter, with a discharge of 1 and 3 liters per minute and contact time of 10 to 120 min. Then the ozone exposure indicators were incubated for 24-48h at 36 ± 1 °C and, finally, the absence of colony growth in the culture medium was considered as the success of ozone in disinfection of infectious solid waste. This process was performed with 4-time replications. Results: The complete removal of B. atrophaeus was obtained for non-compacted and compacted infectious solid waste, at contact time of 15 and 50 min, respectively. The efficiency of removal of B. atrophaeus by the process of wet ozone injection through a glass column was 100% in 30 minutes and by separate injection of water vapor into the contact tank was 100% in 50 minutes. The results of this study showed that the use of ozone technology was effective in the inactivation and destruction of microbial agents in medical solid waste. Conclusion: Employing different advanced technology of oxidization especially ozone in order to decrease the environmental pollution is considered as one of management approaches.

Genome sequences of three plastic-debris-inhabiting fungi isolated from New Zealand waste and recycling management plants.

Cladosporium and Epicoccum are cosmopolitan fungi of the class Dothideomycetes with few cultured and genomic representatives. Here, we report draft reference genome sequences of Epicoccum sp. F181 (GenBank accession number JAJSLS01), Cladosporium sp. F165 (JAJSLR01), and F190 (JAJSLT01) isolated from recycling and waste management facilities in New Zealand.

Microwave pyrolysis of polypropylene, and high-density polyethylene, and catalytic gasification of waste coffee pods to hydrogen-rich gas.

Plastic waste poses a critical environmental challenge for the world. The proliferation of waste plastic coffee pods exacerbates this issue. Traditional disposal methods such as incineration and landfills are environmentally unfriendly, necessitating the exploration of alternative management strategies. One promising avenue is the pyrolysis in-line reforming process, which converts plastic waste into hydrogen. However, traditional pyrolysis methods are costly due to inefficiencies and heat losses. To address this, for the first time, our study investigates the use of microwave to enhance the pyrolysis process. We explored microwave pyrolysis for polypropylene (PP), high-density polypropylene (HDPE), and waste coffee pods, with the latter primarily comprising polypropylene. Additionally, catalytic ex-situ pyrolysis of coffee pod pyrolysis over a nickel-based catalyst was investigated to convert the evolved gas into hydrogen. The single-stage microwave pyrolysis results revealed the highest gas yield at 500 °C for HDPE, and 41 % and 58 % (by mass) for waste coffee pods and polypropylene at 700 °C, respectively. Polypropylene exhibited the highest gaseous yield, suggesting its readiness for pyrolytic degradation. Waste coffee pods uniquely produced carbon dioxide and carbon monoxide gases because of the oxygen present in their structure. Catalytic reforming of evolved gas from waste coffee pods using a 5 % nickel loaded activated carbon catalyst, yielded 76 % (by volume) hydrogen at 900 °C. These observed results were supported by elemental balance analysis. These findings highlight that two-stage microwave and catalysis assisted pyrolysis could be a promising method for the efficient management of waste coffee pods, particularly for producing clean energy.

An observational cross-sectional study of pharmaceutical waste disposal practices in Australian medical imaging departments: A comparison of community versus hospital practice.

INTRODUCTION: Pharmaceuticals are used widely in radiography practice but pose an environmental risk. This study explored Australian radiographers' environmental attitude, pharmaceutical waste disposal practices, and knowledge and concern regarding the environmental impact of these pharmaceuticals. METHODS: This study utilised an anonymous, online questionnaire developed from two validated questionnaires. Participants (n = 150) held current registration with the Medical Radiation Practice Board of Australia and were working eight or more hours per week in a medical imaging practice (public or private). RESULTS: Participants did not answer all questions, hence percentages reported reflect the number of counts for each question. Most participants (71.4%; 105/147) disposed of contaminated pharmaceutical waste in clinical waste bins with 17.1% (15/146) disposing of it down drains. More hospital radiographers 13.54% (13/96) reported this disposal compared with 2.08% (1/48) of community-based radiographers (Fisher's Exact Test, p = 0.035). There was no difference in disposal of non-contaminated waste between practice settings - general waste bin (68.5%; 100/150), recycling bin (28.8%; 42/146), and clinical waste bin (41.8%; 61/146). Participants lacked knowledge of impacts on the food chain and the health of humans and wildlife. Only 34.7% (48/138) of participants expressed concern regarding the impacts of human excreted pharmaceuticals on the environment compared with 65.8% (98/149) regarding impacts from incorrect disposal. Many (18.4%; 25/136) reported having received no information on correct disposal of pharmaceutical waste. CONCLUSION: This study highlighted participants' lack of knowledge on how pharmaceuticals enter the natural environment and the subsequent impacts on the environment and on the health of humans, and flora and fauna. They lacked knowledge of correct pharmaceutical waste disposal methods, but most agreed it was their professional responsibility to dispose of waste correctly. IMPLICATIONS FOR PRACTICE: Improving radiographers' pharmaceutical waste disposal practices through education and professional support will reduce environmental impacts and also provide financial co-benefits if non-contaminated waste is recycled where possible and not incinerated.

Waste newspaper as cellulose resource of activated carbon by sodium salts for methylene blue and congo red removal.

The work was aimed at evaluating the adsorptive properties of waste newspaper (WN) activated carbons chemically produced using sodium salts for methylene blue (MB) and congo red (CR) removal. The activated carbons, designated as AC1, AC2, AC3 and AC4 were prepared through impregnation with NaH2PO4, Na2CO3, NaCl and NaOH, respectively and activation at 500 °C for 1 h. The activated carbons were characterized for surface chemistry, thermal stability, specific area, morphology and composition. The AC1 with a surface area of 917 m2/g exhibits a greater MB capacity of 651 mg/g. Meanwhile, a greater CR capacity was recorded by AC2 at 299 mg/g. The pseudo-second order model fitted well with the kinetic data, while the equilibrium data could be described by Langmuir model. The thermodynamic parameters, i.e.., positive ΔH°, negative ΔG° and positive ΔS° suggest that the adsorption of dyes is endothermic, spontaneous and feasible at high solution temperature. To conclude, WN is a potential cellulose source for producing activated carbon, while NaH2PO4 activation could be employed to convert WN into activated carbon for effective dye wastewater treatment.

Biohythane production via anaerobic digestion process: fundamentals, scale-up challenges, and techno-economic and environmental aspects.

Biohythane, a balanced mixture comprising bioH2 (biohydrogen) and bioCH4 (biomethane) produced through anaerobic digestion, is gaining recognition as a promising energy source for the future. This article provides a comprehensive overview of biohythane production, covering production mechanisms, microbial diversity, and process parameters. It also explores different feedstock options, bioreactor designs, and scalability challenges, along with techno-economic and environmental assessments. Additionally, the article discusses the integration of biohythane into waste management systems and examines future prospects for enhancing production efficiency and applicability. This review serves as a valuable resource for researchers, engineers, and policymakers interested in advancing biohythane production as a sustainable and renewable energy solution.

EXPRESS: Standoff Identification of Plastic Waste Using a Low-Cost Compact Laser-Induced Breakdown Spectroscopy LIBS Detection System.

We report the standoff/remote identification of post-consumer plastic waste by utilizing a low-cost and compact standoff laser-induced breakdown spectroscopy (ST-LIBS) detection system. A single plano-convex lens is used for collecting the optical emissions from the plasma at a standoff distance of 6.5 m. A compact non-gated Czerny-Turner charge-coupled device (CCD) spectrometer (CT-CCD) is utilized to analyze the optical response. The single lens and CT-CCD combination not only reduces the cost of the detection system by ten folds, but also decreases the collection system size, weight compared to heavy telescopic-based intensified CCD (ICCD) systems. All the samples investigated in this study were collected from a local recycling plant. All the measurements were performed with only a single laser shot which enables rapid identification while probing a large number of samples in real time. Furthermore, principal component analysis has shown excellent separation among the samples and an artificial neural network analysis has revealed that plastic waste can be identified within ∼10 ms only (testing time) with accuracies up to ∼99%. Finally, these results have the potential to build a compact and low-cost ST-LIBS detection system for the rapid identification of plastic waste for real-time waste management applications.

Re-using an oleic by-product in the manufacturing of fired clay bricks.

Background: The high demand for building bricks underscores their essential role in the construction industry, which pushes researchers to continuously improve the characteristics of these products. This study aimed to investigate the impact of incorporating oleic components (Margins) in fired bricks manufacturing of by substituting water with different percentages of margins. Methods: Fired bricks were produced at the laboratory using clays taking from the Tangier region in northern Morocco. During this process, water used in the bricks production was substituted with margins in increasing percentages ranging from 10 % up to 30 %. To validate the results obtained from the physicochemical analyses performed on the manufactured bricks, three types of vegetable samples from three different regions of Morocco were utilized. Result: The study results are very remarkable, demonstrating a significant enhancement in compressive strength. The strength increased from 15.16 MPa for conventional bricks to 33.77 MPa for bricks manufactured with a 30 % substitution. Furthermore, porosity decreased from 33 % to 19 %. Conclusion: By integrating oleic components into the manufacturing process, we were able to achieve three main objectives.1. We have improved the characteristics of the bricks, which tend towards the load-bearing wall standards.2. We reduced the water quantity used in the bricks manufacturing by 30 %.3. We minimized the processing cost of the waste resulting from olive oil production, as well as its harmful effects on the environment.

Sustainable resilient E-waste management in London: A circular economy perspective.

The circular economy (CE) is reasoned to organize complex systems supporting sustainable resilience by distinguishing between waste materials and economic growth. This is crucial to the electronic waste (e-waste) industry of developed countries, and e-waste operation management has become their top priority because e-waste contains toxic materials and valuable sources of elements. In the UK, although London Metropolitan city boasts an ambitious sustainable resilience target underlying the context of CE, practical implementation has yet to be feasible, with few investigations detailing if and how the existing target implications enable industrial and social-ecological sectors to continue their performance functionalities in the face of undesired disruptions. In this paper, a dynamic Bayesian Network (dynamic BN) approach is developed to address a range of potential risks. The existing London e-waste operation management is considered as an application of study for sustainable resilience development. Through the utilization of dynamic BN, a comprehensive analysis yields a Resilience Index (RI) of 0.5424, coupled with a StdDev of 0.01350. These metrics offer a profound insight into the intricate workings of a sustainable system and its capacity to swiftly rebound from unexpected shocks and disturbances. This newfound understanding equips policymakers with the knowledge needed to navigate the complexities of sustainable e-waste management effectively. The implications drawn from these in-depth analyses furnish policymakers with invaluable information, enabling them to make judicious decisions that advance the cause of sustainable e-waste management. The findings underscore that the absorptive capacity of a sustainable and resilient e-waste operation management system stands as the foremost defense mechanism against unforeseen challenges. Furthermore, it becomes evident that two pivotal factors, namely "diversifying the supply chain" and "enhancing supply chain transparency," play pivotal roles in augmenting the sustainability and resilience of e-waste operation management within the context of London's ambitious sustainability targets. These factors are instrumental in steering the trajectory of e-waste management towards a more sustainable and resilient future, aligning with London's aspirations for a greener and more eco-conscious future.

Frequency of occupational health hazards and factors responsible among the waste handlers at the tertiary care hospitals of Karachi.

Background & Objectives: Hospital waste handlers (HWHs) are in contact with contaminated waste that put them at risk for occupational health hazards. The objective of the study was to determine the frequency of occupational health hazards and identify factors contributing to them among the HWHs at tertiary care hospitals of Karachi. Methods: A cross sectional survey was conducted from January 2021 till June 2022 on 417 conveniently selected HWHs of the public and private tertiary care hospitals of the Karachi including three Public sector hospitals (Civil Hospital Karachi, National Institute of Child Health, Jinnah Post Graduate Medical Center) and five private sector hospitals (Sohail University Hospital, Darulsehat Hospital, Kharadar General Hospital, Patel Hospital and Hamdard University Hospital) using a structured questionnaire. Chi Square test was applied to determine the differences in occurrence of different hazardous outcomes (Needle stick injury, Sharp Injury, Eye Symptoms, Skin symptoms, Cough) between different groups of age, gender, type of hospitals and status of being trained in Hospital Waste Management (HWM). Results: Around half of the HWHs (52.6%) labeled the bins of the waste according to their level of hazard. Only 17.9% disinfected the infected waste. The proportion of participants who experienced needle stick and sharp injury in the last six months was 16.3% and 15.8% respectively. Majority of them used disposable gloves (95.7%) and face masks (94.3%). One thirds had access to aprons while only 10.5% had access to protective shoes at their work place. HWHs of private sector were significantly less likely to experience Needle stick injuries, skin symptoms, cough, breathing difficulty and throat burning. Conclusion: The HWM practices in tertiary care hospitals of Karachi is far from being satisfactory. HWHs must be trained and monitored for safe disposal of waste.

Acidic process fluid from hydrothermal carbonization improves dechlorination of waste PVC and produces clean solid and liquid fuels.

Dechlorination of waste PVC (WPVC) by hydrothermal treatment (HTT) is a potential technology for upcycling WPVC in order to create non-toxic products. Literature suggests that acids can improve the HTT process, however, acid is expensive and also results in wastewater. Instead, the acidic process fluid (PF) of hydrothermal carbonization (HTC) of orange peel was utilized in this study to enhance the dechlorination of WPVC during HTT. Acidic HTT (AHTT) experiments were carried out utilizing a batch reactor at 300-350 °C, and 0.25-4 h. The finding demonstrated that the dechlorination efficiency (DE) is high, which indicates AHTT can considerably eliminate chlorine from WPVC and relocate to the aqueous phase. The maximum DE of 97.57 wt% was obtained at 350 °C and 1 h. The AHTT temperature had a considerable impact on the WPVC conversion since the solid yield decreases from 56.88 % at 300 °C to 49.85 % at 350 °C. Moreover, AHTT char and crude oil contain low chloride and considerably more C and H, leading to a considerably higher heating value (HHV). The HHV increased from 23.48 to 33.07 MJ/kg when the AHTT time was raised from 0.25 to 4 h at 350 °C, indicating that the AHTT time has a beneficial effect on the HHV. The majority fraction of crude oil evaporated in the boiling range of lighter fuels include gasoline, kerosene, and diesel (57.58-83.09 wt%). Furthermore, when the AHTT temperature was raised from 300 to 350 °C at 1 h, the HHV of crude oils increased from 26.11 to 33.84 MJ/kg. Crude oils derived from AHTT primarily consisted of phenolic (50.47-75.39 wt%), ketone (20.1-36.34 wt%), and hydrocarbon (1.08-7.93 wt%) constituents. In summary, the results indicated that AHTT is a method for upcycling WPVC to clean fuel.

An innovative environmental tool to evaluate the sustainability of anthropogenic processes: the tetrahedron approach.

The Tetrahedron approach is a new environmental tool adapted to assess the sustainability of anthropogenic processes. This tool is based on a four-step methodology that includes (a) the identification of critical parameters, (b) evaluation through the Tetrahedron Parameter Global Evaluator, (c) construction of a tetrahedron diagram based on the final scores and (d) quantitative estimation of the global sustainability. The Tetrahedron incorporates various aspects of sustainability, including economic, social and environmental factors, and provides a comprehensive framework for evaluating the impact of human activities. This article presents the methodology and application of the Tetrahedron in determining the sustainability of five case studies: CO2 capture, unconventional methanol production, the Solvay process, CO2-alcoholic fermentation process strategy and the CO2-Rumen fermentation process strategy. The results demonstrate the Tetrahedron as an effective and reliable tool to quantify the sustainability of anthropogenic processes and to promote sustainable practices across various industries and sectors. The Tetrahedron offers several advantages over other environmental assessment tools, including holistic approach, simplicity and flexibility.

Uranium mining effluents: What about the re-use of mining wastes to improve the bioproduction of industrially relevant bioactive compounds?

The shift towards a circular economy, where waste generation is minimized through waste re-use and the development of valorization strategies, is crucial for the establishment of a low carbon, sustainable, and resource-efficient economy. However, there is a lack of strategies for re-using and valorizing specific types of waste, particularly those containing naturally occurring radioactive materials (NORM), despite the prevalence of industrial activities that produce such waste due to their chemical and radiological hazards. Living organisms, including fungi, are valuable sources of bioactive compounds with various industrial applications. In this study, we assessed the growth and metabolic profile changes of three white rot fungi species in response to low concentrations of a uranium mine effluent containing NORM and metals to explore their potential for producing biotechnologically relevant bioactive compounds. The growth rate was assessed in three different culture media, with and without the uranium mine effluent (1% V/V)), and the metabolic profile was analyzed using FTIR-ATR spectroscopy. Results suggested an improvement in growth rates in media containing the uranium mine effluent, although not statistically significant. T. versicolor showed promise in terms of bioactive compound production. The production of droplets during growth experiments and significant metabolic changes, associated with the production of bioactive compounds like laccase, melanin, and oxalic acid, were observed in T. versicolor grown in mYEPDA with the uranium mine effluent. These findings present new research opportunities for utilizing waste to enhance the biotechnological production of industrially relevant bioactive compounds and promote the development of circular economy strategies for re-using and valorizing NORM-containing waste.

Harnessing phosphate limestone waste as a cost-effective solution for acid mine drainage treatment.

Mining mineral ores like pyrrhotite often generates positive and negative outcomes for the community. On the one hand these valuable minerals are explored to provide economic opportunities. On the other, mining pyrrhotite presents adverse environmental and health effects that relates to acid mine drainage (AMD) formation in abandoned mines. This suggest that the sustainable mining of valuable minerals in Pyrrhotite requires cost and environmentally friendly approaches. In this research, we simulate in-situ neutralisation effect of phosphate limestone waste (PLW) on AMD from two mining sites in Morocco under continuous oxic conditions. To this end, we conducted batch tests to assess the effectiveness of PLW in mitigating AMD and releasing contaminants. These tests involved reacting limestone particles (at two sizes: <2 cm and < 4 cm) with AMD leachates over a five-day period The results indicated that the AMD is characterised by a pH of 2.5 and an electrical conductivity of 11.8 mS/cm. The inductively coupled plasma optical emission spectroscopy (ICP-OES) analyses showed a high sulfate concentration of 3668.83 mg/L and the presence of some metals, notably copper, aluminium, and iron. The neutralisation process of the AMD using PLW under oxic conditions was highlighted by the variation in pH while the water was in contact with the PLW. The pH rose from 2.5 to 5.25 while the electrical conductivity decreased from 11.8 to 7.03 mS/cm. During the treatment of the AMD with PLW, the percentage of sulfate removal from the effluent was 35 %. In addition, iron and aluminium were significantly removed from the AMD with a percentage of 99 % in the leachate. Therefore, these results indicate that neutralising AMD using this passive treatment approach is effective and may serve as a cost-effective mitigation for AMD, since no excessive grinding is required for the PLW.

Impact of virgin and recycled polymer fibers on the rheological properties of cemented paste backfill.

The addition of polymer fibers to cemented paste backfill (CPB) has shown promise in enhancing mechanical properties, although it also introduces changes in rheological characteristics. This study aimed to investigate the influence of different types of polymer fibers, namely virgin commercial polypropylene fiber (CPPF), recycled tire polymer fiber (RTPF), and recycled tire rubber fiber (RF), on the rheological properties of CPB mixtures through an experimental program, and provide design references for CPB pipeline transport. The results revealed consistent reductions in bulk density upon the incorporation of polymer fibers into CPB, alongside varying impacts on slump. Specifically, the addition of CPPF had a mild effect, while RTPF caused a continuous decrease in slump, and RF exhibited minimal influence up to a 4% concentration, with substantial effects thereafter. Moreover, the inclusion of fibers led to increases in apparent viscosity parameters, with RTPF inducing the most significant changes, followed by varying responses from CPPF and RF. When using RTPF for CPB reinforcement, emphasis should be placed on enhancing technical indicators related to viscosity such as energy consumption and pipeline wear during pipeline transport. Furthermore, adjustments were necessary to account for flow curve instability resulting from interactions between fibers and the paddle, with the data aligning well with the Bingham model. The addition of fibers, particularly CPPF and RF, primarily influenced plastic viscosity rather than yield stress, underscoring the limitations of slump tests in assessing rheology.

Characterisation of Bambara groundnut (Vigna subterranea (L.) Verdc.) shell waste as a potential biomass for different bio-based products.

Efforts are ongoing to utilise agricultural waste to achieve a full resource use approach. Bambara groundnut is an important crop widely grown in the sub-Saharan Africa with potential future importance because of its resilience to thrive under heightened weather uncertainty and widespread droughts that have challenged food security. After harvesting, the edible nuts are separated from the shells which are discarded as waste. Therefore, this research is aimed at characterising the chemical composition and the structural properties of Bambara groundnut shells (BGS) in view of their potential application as a biomass for different bio-products. The chemical composition of BGS was found to be 42.4% cellulose, 27.8% hemicellulose, 13% lignin and 16.8% extractives. Proximate analysis showed a high amount of volatile matter (69.1%) and low moisture (4.4%). XRD analysis confirmed crystallinity of cellulose I polymer and FTIR analysis observed functional groups of lignocellulosic compounds. Thermal stability, maximum degradation temperature and activation energy were found to be 178.5 °C, 305.7 °C and 49.4 kJ/mol, respectively. Compared to other nutshells, BGS were found to have a relatively high amount of cellulose and crystallinity that may result in biocomposites with improved mechanical properties.

Valorizing date palm spikelets into activated carbon-derived composite for methyl orange adsorption: advancing circular bioeconomy in wastewater treatment-a comprehensive study on its equilibrium, kinetics, thermodynamics, and mechanisms.

Leveraging date palm spikelets (DPS) as a precursor, this study developed a DPS-derived composite (ZnO@DPS-AC) for water treatment, focusing on methyl orange (MO) removal. The composite was synthesized through ZnCl2 activation and pyrolysis at 600 °C. Comprehensive characterization was conducted using TGA, FTIR, XRD, SEM/EDS, and pHPZC. Characterization revealed a highly carbonaceous material (> 74% carbon) with significant porosity and surface functional groups. ZnO@DPS-AC demonstrated rapid MO removal, achieving over 45% reduction within 10 min and up to 99% efficiency under optimized conditions. The Langmuir model-calculated maximum adsorption capacity reached 226.81 mg/g at 20 °C. Adsorption mechanisms involved hydrogen bonding, π-π interactions, and pore filling. The composite showed effectiveness in treating real wastewater and removing other pollutants. This study highlights the potential of agricultural waste valorization in developing efficient, sustainable adsorbents for water remediation, contributing to circular bioeconomy principles.