Chemical Consumption Research Articles

Unveiling the Detrimental Impacts of Intensive Chemical Use and Monoculture on Soil Health and Sustainable Development Goal 15: Life on Land in Telangana

Objective: The primary objective of this research is to investigate the implications of excessive chemical use in agriculture and its detrimental impact on the environment. The study aims to highlight the urgent need for a shift towards sustainable farming practices that prioritize both productivity and ecological preservation. Theoretical Framework: The research appears to be grounded in the concept of Sustainable Development Goals (SDGs), emphasizing the balance between economic growth, social progress, and environmental protection. It aligns with the understanding that intensive agricultural practices, while boosting yields, can have severe ecological consequences. Method: Researchers employed a descriptive survey methodology to gather data through semi-structured interviews, case studies, and group discussions. This mixed-methods approach provided a comprehensive understanding of farmers' practices and challenges. The collected data was analysed using SPSS software with a focus on descriptive statistics. Results and Discussion: The findings are alarming, indicating a heavy reliance on chemicals (98.2%) and a widespread adoption of monocropping (84.8%), particularly cotton cultivation. The study also revealed a decline in traditional farming practices with a shift towards mechanized methods (87.6%). Furthermore, there is growing scepticism among farmers about the effectiveness of livestock manure as a fertilizer. These results underscore the urgent need for sustainable alternatives. Research Implications: The study's findings affect lawmakers, farmers, and environmentalists. Sustainable agriculture practices that reduce chemical use, promote biodiversity, and protect soil health are urgently needed. The research also emphasises the importance of educating farmers about the long-term effects of current methods and the benefits of sustainable ones. Originality/Value: This article presents empirical facts on agricultural chemical consumption and related issues, advancing current knowledge. By evaluating the issue from a sustainable development goals viewpoint, the research illuminates the complex relationship between agricultural productivity and environmental preservation. The findings can inform legislation and actions to promote environmentally friendly agriculture.

Recycling valuable metals from spent cathode material by in-situ thermal reduction combined with electrochemical leaching

In-situ thermal reduction is a promising technology that realizes the reduction of high-valence metals in spent lithium-ion batteries (LIBs) through its reductive substances. However, the subsequent simple acid leaching cannot adapt to all thermal reduction products, especially elemental Ni and Co, resulting in low leaching efficiency and high acid consumption. In this work, in-situ thermal reduction combined with electrochemical-enhanced leaching technology was provided for extracting valuable metals from spent LIBs with minimum chemical consumption. Results show that after thermal reduction, the layered structure of LiNi1/3Co1/3Mn1/3O2 was fully broken, yielding acid-soluble components including Ni, Co, NiO, CoO, MnO, Li2CO3, and LiAlO2, all achieved without external reductants. During the electrochemical leaching, the acidic solution produced by water electrolysis and electrochemical oxidation synergistically promoted the leaching of valuable metals, and finally, 99.02 % Li, 96.34 % Ni, 98.28 % Co and 99.24 % Mn were leached from the roasted cathode product. Compared with traditional acid leaching, the proposed electrochemical method has advantages in the dissolution of elemental Ni and Co. Moreover, the whole process does not consume any external acids or bases, and there is no emission of waste acid. The findings of this work help to reduce reagent consumption in the spent LIBs recycling process and provide an effective, adaptable, and green method for leaching thermal reduction products.

Optimization of Combined Pre-Treatment Process for Bleaching of Cotton Woven Fabric Using Box–Behnken Design

ABSTRACT The conventional bleaching process for cotton woven fabrics is characterized by high consumption of chemicals, water, and energy, resulting in significant environmental impact through elevated energy use and wastewater discharge. To address these concerns and align with sustainable development goals, there is an urgent need for eco-friendly alternatives that minimize environmental footprint while maintaining fabric quality. This study presents the development and optimization of a novel one-bath pre-treatment process for cotton bleaching, employing the Box-Behnken design to enhance sustainability. The optimized process utilizes 32% hydrogen peroxide and 12% sodium hydroxide based on fabric weight, operating at 90°C. The application of the Box-Behnken design facilitated substantial reductions in chemical usage, energy consumption, and wastewater output. The results demonstrated notable improvements in fabric properties, with a whiteness index of 139.5, weight loss of 7.9%, and tensile strengths of 404.9 N (warp) and 259.5 N (weft). Moreover, fabric absorbency increased by 9.3% compared to conventional methods. The findings underscore the efficacy of the Box-Behnken design in optimizing a more sustainable and eco-friendly bleaching process, which not only significantly enhances fabric performance but also offers considerable environmental benefits. This approach presents a promising solution for the textile industry to achieve greener practices while maintaining high-quality standards.

Implementation of selective flocculation process in drilling operations to optimize per-flex fluid volume consumption and reduce the carbon footprint

One of the significant challenges faced by the oil and gas industry is the reduction of the carbon footprint associated with drilling operations. This paper presents a case study on the implementation of a selective flocculation process to optimize the consumption of PER-FLEX fluid, a high-performance water-based mud (WBM), during drilling operations. Conducted in a Colombian oil field, this study demonstrates how the adjustment of polymer concentration and injection rates in the flocculation process can reduce the need for fluid dilution, thereby decreasing water and chemical consumption, waste production, and CO2 equivalent (CO2 eq.) emissions. The findings highlight the effectiveness of selective flocculation in enhancing drilling fluid performance and contributing to sustainability goals.

Catalytic merits of Ni0.6Zn0.4Fe2O4/f-MWCNTS–CS–Asp/Ni2+ for tailoring 1H-benzo [4,5] imidazo [1,2-b] [1,2,4]triazepine motifs through green domino strategy

The magnetic nano catalyst mediated synthesis of heterocycles is one of the most fascinating fields of chemistry due to its proven applicability in high-efficiency, eco-friendly and recyclable heterogeneous catalytic system. In order to design a novel Ni0.6Zn0.4Fe2O4/f-MWCNTs–CS–Asp/Ni2+ magnetic heterogeneous catalyst, Ni0.6Zn0.4Fe2O4-decorated multi walled CNTs were modified with crosslinked chitosan with l-aspartic acid entrapped Ni2+ nanoparticles. This nano catalyst showed significant catalytic activity in the synthesis of biologically potent novel seven membered heterocycles embracing fused 1H-benzo [4,5]imidazo [1,21,2-b][1,2,4]triazepine skeleton. Owing to its interesting structure and being an important pharmacophore fragment, it was endeavored to exploit its synthesis. For the first time considering an exquisite and accomplishable access to construct (Kaur et al., 2021; Jiang et al., 2006; Stern, 1980) [1,2,4]triazepine framework. In addition, the structures of synthesized heterocycles and morphology of nano catalyst were corroborated on the basis of various spectroscopical and microscopical techniques. Furthermore, employing ultrasonication as energy source in the synthesis of magnetic nano catalyst employing 3R's (reduce, recycle and reuse), mild reaction conditions with appreciable yield along with no consumption and production of hazardous chemicals put it under the umbrella of green and sustainable approach.

Dry cleaning of InSb surfaces by hydrogen molecule exposure in ultrahigh vacuum

Cleaning semiconductor surfaces by atomic hydrogen or hydrogen plasma has gained significant interest because such a dry-cleaning method enables to reduce consumption of chemicals and pure water, and to treat challenging surfaces of three-dimensional semiconductor nanostructures. We have studied effects of mere H2 molecule exposures on (111)B and (110) surfaces of InSb with native oxides in an ultrahigh-vacuum (UHV) chamber. Without any hydrogen cracking, exposure of native-oxide covered InSb(111)B, heated simultaneously at 350 °C, to H2 with a partial pressure of 5∙10−5 mbar decreases amount of surface oxides and carbon, according to x-ray photoelectron spectroscopy, and provides (2×2) low-energy electron diffraction (LEED) pattern. Scanning tunneling microscopy indicates that this InSb(111)B(2×2) surface contains still extra Sb. When the InSb temperature increases to 400 °C during the H2 exposure, LEED changes to (3×3) pattern, which is known to arise from a less Sb-rich surface compared to InSb(111)B(2×2). When InSb(111)B(3×3) is exposed to H2 at the lowered temperature of 300 °C, LEED changes back to (2×2), which is discussed to arise from that InSb(111)B(3×3) contains still oxygen. Experiments for InSb(110) support that the found H2 exposure effects apply to different crystal faces of InSb.

Prediction and optimization of wastewater treatment process effluent chemical oxygen demand and energy consumption based on typical ensemble learning models

Pollution integration and carbon reduction has become a primary focus in wastewater treatment processes. In this study, water quality and control indicators were used as input features and the dataset was extended using the moving average method. Random Forest, eXtreme Gradient Boosting (XGBoost), and Light Gradient Boosting Machine algorithms were used to predict the effluent chemical oxygen demand (COD) and total energy consumption (TEC). The results indicated that the model prediction performance could be effectively improved when the data were amplified by two times and that the XGBoost model exhibited the best prediction performance for effluent COD and TEC. The Non-dominated Sorting Genetic Algorithm II model was employed for the multi-objective optimization of effluent COD and TEC, resulting in reductions of 15% and 18%, respectively. The ensemble learning model proposed in this study to achieve synergy between water quality improvement and energy saving is practical.

Modelling the predictive analysis of turbidity removal efficiency in the in-line coagulation and flocculation process

Coagulation and flocculation processes are commonly used in conventional water treatment plants to remove suspended solids from water. However, these methods often suffer from drawbacks such as high chemical consumption, sludge generation, and the need for huge areas, leading to high construction costs. To address these limitations, this study investigated the performance of in-line coagulation and flocculation processes as an alternative to conventional methods. The objectives were to determine the efficiency of in-line coagulation and flocculation, understand the underlying mechanisms, establish optimal operating conditions and design criteria, and to develop theoretical models for predicting turbidity removal efficiency in the in-line coagulation-flocculation process. Experiments were conducted using a continuous setup consisting of a static mixer and a 35-m helically coiled hydraulic tube flocculator.Various operating parameters, including water flow rate (100 – 800 L/hr), initial turbidity (20 – 200 NTU), and coagulant types (aluminum sulfate, poly aluminum chloride, aluminum chlorohydrate, and ferric chloride), were examined. The results demonstrated that aluminum sulfate was the appropriate coagulant for the water characteristics studied, and the in-line coagulation and flocculation processes achieved turbidity removal efficiencies of approximately 91 % under all operating conditions, with a notable 97 % removal efficiency achieved at a liquid flow rate of 600 L/hr, with a Gt value of 21,715 and an overflow rate of 2 m/hr. A prediction model of turbidity removal efficiency was developed, showing good agreement between experimental and predicted removal efficiency model, with an average deviation of about 20 %. This model can aid in determining optimal operating conditions and serve as a hybrid process in future water treatment systems, potentially applicable to other separation processes as well.

Optimizing water-energy-food nexus index, CO2 emissions, and chemical pollutants under irrigation water salinity scenarios

The escalation of crises related to water quantity of quality, energy, food, and the environment has posed numerous challenges to sustainable development in the agricultural sector. This study seeks to establish an optimal and sustainable framework within the agricultural sector by meeting the objectives of the WEF (Water-Energy-Food) nexus index and environmental. For this, we individually optimized the objectives: maximizing the WEFN index (O1), minimizing CO2 emissions (O2), reducing chemical fertilizer consumption (O3), minimizing chemical pesticide usage (O4), and maximizing gross margin (O5) under various electrical conductivity (EC) scenarios (optimistic, moderate, and pessimistic) within the irrigation network of the Jiroft plain in Iran. In the second stage, we employed a Multi-Objective Programming (MOP) Model to attain these objectives using a weighted sum approach simultaneously. The results of the first stage revealed that under moderate and pessimistic EC irrigation water scenarios, significant alterations in the crop selection within the optimized models for O1 and O5 objectives occurred compared to the baseline scenario, which did not consider EC irrigation water. Specifically, in the pessimistic scenario with an EC irrigation water level of 2.25 ds/m, crops such as onions, tomatoes, and potatoes were replaced within the optimal cropping pattern by wheat, barley, and green-maize, leading to a notable decline in program efficiency. The results from the MOP optimization model indicated that in the pessimistic EC irrigation water scenario, the WEFN index, CO2 emissions, fertilizer consumption, pesticide consumption, and gross margin would change by approximately +12%, −48%, −28%, −8%, and −74%, respectively, compared to the baseline scenario. Consequently, an increase in EC irrigation water, despite improving environmental conditions, would substantially diminish economic profit. Thus, overlooking the impact of EC irrigation water in the WEF nexus analysis could result in misleading conclusions.

Quantifying oxygen diffusion during thermal degradation of combustible porous media

Oxygen diffusion controlled combustion occurs when local oxygen transport is slower than the chemistry, commonly found in porous combustible material or combustible material embedded within an inert porous medium. This mode of combustion, such as smouldering, can pose dangerous fire risks and also be harnessed in environmentally beneficial applications. However, the oxygen diffusion limitation is poorly understood in all contexts and persists as a key knowledge gap. Quantitative analysis of oxygen diffusion effects is therefore crucial for understanding the combustion behavior of combustible porous media and developing precise smouldering simulation models. In this paper, a reactive transport model incorporating both oxygen diffusion and chemical consumption was developed. Using coal as the model fuel, the impacts of key parameters on global mass loss during the one-dimensional diffusion combustion of coal samples were simulated and compared with TGA experiments conducted within a range of oxygen concentrations between 3–21%. Using this method, key kinetic and oxygen diffusion parameters were obtained within reasonable ranges by using a genetic algorithm optimization method. With these optimized parameters, the local oxygen distribution profiles in the samples at different inlet oxygen concentrations were simulated. The results indicate that oxygen diffusion can lead to large oxygen concentration differences within the coal samples, exceeding 63% of the inlet oxygen concentration. These oxygen differences can impact the local chemistry throughout the sample, and lead to fundamental errors in analyzing global kinetic analyses, if the transport effects are not considered. Altogether, this study delivers new insights into a potentially rate-limiting phenomenon that is relevant in progressing knowledge on many fire problems and engineering applications.

Combined effects of organic solvent and ultrasonic pretreatments on cellulose fiber extraction from hemp

Extracting pure cellulose fibers from hemp bast for potential textile industry applications requires the removal of non-cellulosic gummy materials. However, traditional degumming methods are largely limited because of the long procedure time, high energy consumption, heavy environmental pollution and insufficient efficiency. Organic solvents have been proved to be an innovative method for lignocellulose extraction. Herein, ethylene glycol solvent combined ultrasonic pretreatment was explored to degum hemp fibers without any further treatment. The purified hemp fibers were systematically characterized using analytical test techniques. Results revealed that the combined degumming could effectively remove non-cellulosic components without damaging the cellulose, and reducing the reaction temperature by 10 ℃ for reaction process. Comparing to the traditional method, the fibers by ultrasonic pretreatment-ethylene glycol process had superior average yield of 68.32 %, higher thermal stability (maximum degradation temperature reached 395 ℃), higher breaking tenacity of 6.13 cN/dtex, higher crystallinity of 78 % and the cellulose content of over 91 %. Moreover, the degumming time and chemical usage were reduced to 40 % and 51.8 %, respectively. Besides, the changes of fibers chemical structure were further investigated and verified by FTIR, EDS, and 13C NMR analysis. Featured with less chemical and energy consumption, eco-friendly and short time-consuming, this treatment has a broad application scope for hemp cellulose fiber extraction.

Enhanced oil recovery and mitigating challenges in sandstone oil reservoirs employing EDTA chelating agent/ seawater flooding

While low salinity water (LSW) holds promise for improving oil recovery, its implementation is comparatively costly due to the substantial volumes of fresh water required to dilute seawater (SW). Additionally, concerns arise regarding potential issues related to LSW, including fines migration in sandstone reservoirs and scale formation in carbonate reservoirs. Chelating agents can be introduced into undiluted SW to bind with metal ions, thereby lowering its salinity. This approach mimics the behavior of LSW injection while overcoming associated challenges. This study involves measuring oil/injected solution interfacial tension (IFT), evaluating sandstone surface wettability alteration, along with conducting different sand pack flooding scenarios using Ethylenediaminetetraacetic acid (EDTA) chelating agent. The aim was to comprehend the EDTA oil recovery mechanisms and determine the optimal concentration of EDTA that minimizes chemical consumption while maximizing oil recovery. The findings indicated that incorporating 5 wt% EDTA into SW significantly reduced IFT from 29.52 mN/m to 4.75 mN/m, making the oil nearly miscible in the solution. Moreover, wettability tests confirmed that a minimum EDTA concentration of 5 wt% is required to shift wettability from oil-wet to strongly water-wet conditions. Sand pack flooding experiments, on the other hand, further demonstrated that this optimized fluid system can potentially recover an additional 16.1 % of oil following SW flooding. Finally, inductively coupled plasma (ICP) analysis revealed a notable increase in metal ion concentration during EDTA flooding, indicating enhanced leaching of metals from the sandstone surface and improved wettability characteristics.

Electrochemical Recovery of Cd and Te from CdTe Solar Panels

CdTe photovoltaic (PV) solar panel occupies approximately 5% of the PV solar panel market worldwide, as the second deployed PV technology following crystalline silicon. To ensure a circular economy of critical materials, it is important to recover Cd and Te from end-of-life CdTe solar cells. Current industrial recycling processes of CdTe solar panels involve multiple stages of chemical oxidation, separation, and precipitation, which require high energy and chemical consumption. Different electrochemical processes are compared and evaluated to recover Cd and Te from shredded CdTe solar cells as possible alternatives. Cd and Te are selectively leached and precipitated with mediated electrochemical oxidation processes. In this ongoing work, electrochemical systems show potential to decarbonize the CdTe recycling industry.

Chemical weathering and CO2 consumption rates of the Koshi River Basin: modelling and quantifying

The Koshi River is a typical river originating from the Tibetan Plateau that drains into the Indian Plain. To quantify the chemical weathering and CO2 consumption rates of the upstream alpine meltwater-supplied mountainous and downstream rainfall-impacted temperate plain regions, 46 river water samples were collected at 23 sites during monsoon and post-monsoon seasons, and major ions concentrations were measured in the laboratory. The forward model was applied to calculate carbonate weathering rate (CWR), silicate weathering rate (SWR), and their CO2 consumption rates ([CO2]car and [CO2]sil). For investigating the hydrological impacts, correlation analysis was applied between the chemical weathering rates and different runoff components based on the Spatial Process in Hydrology model at each sampling site. Results show that carbonate and silicate rock weathering control the river water chemistry. The average silicate weathering rate is 7.37 tons/km2/yr, consuming 3.40 × 105 mol/km2/yr CO2 while considering sulfide-involved carbonate weathering, the carbonate weathering rate is 26.35 tons/km2/yr, consuming 3.82 × 105 mol/km2/yr CO2. Overall, chemical weathering and CO2 consumption rates are enhanced in monsoon season in both the upstream and downstream regions owing to the intense hydrological cycle. These rates are relatively higher in the alpine upstream region during the post-monsoon season due to intense physical erosion, and higher in downstream during the monsoon season due to the greater volume of water. The significant positive correlations between snowmelt runoff with CWR and [CO2]car indicated that the rising precipitation and temperature leading to enhanced snowmelt would increase the carbonate weathering rate. Hence, this study provides a valuable understanding of the spatiotemporal variations in river hydrochemistry and the role of hydrology in shaping chemical budget within the snow and glacier-fed Himalaya River Basins.

Optimizing the placement of medical wastewater outlets in sewer systems to reduce chemical consumption at wastewater treatment plants

The severely low influent chemical oxygen demand (COD) concentration at wastewater treatment plants (WWTPs) has become a critical issue. A key factor is the excessive biodegradation of organic matter by microbial communities within sewer systems. Intense disinfection commonly adopted for medical wastewater leads to abundant residual chlorine entering sewers, likely causing significant changes in microbial communities and sewage quality in sewers, yet our understanding is limited. Through long-term sewer simulation batch tests, this study revealed the response mechanism of microbial communities to residual chlorine and its impact on organic matter concentration in sewage. Under residual chlorine stress, microbial community structure rapidly changed, and more complex microbial interactions were observed. Besides, pathways related to stress response such as two-component system were significantly enriched; pathways related to energy metabolism (such as carbon fixation in prokaryotes and citrate cycle) in microbial communities were inhibited, and carbon metabolism shifted from the Embden-Meyerhof pathway to the pentose phosphate pathway to enhance cellular reducing power, reduce oxidative stress, and consequently decrease organic matter degradation. Therefore, compared to sewers with normal disinfection, concentrations of COD and dissolved organic carbon in sewage under chlorine stress increased by 12.6 % and 7.4 %, respectively. Besides, the decay and transformation of residual chlorine in sewers were explored. These findings suggest a new approach to medical wastewater discharge management: placing the medical wastewater outlet at the upstream in sewer systems, which ensures that residual chlorine consumption reaches maximum during long-distance transportation, mitigating its harmful effects on WWTPs, and increases the influent organic matter concentration, thereby reducing the need for additional carbon sources.

Innovative process for sulphur recovery from waste incineration flue gases: production of marketable sodium bisulphite solution

ABSTRACT This study presents an innovative process for recovering sulphur from hazardous waste incineration flue gases, designed to produce a marketable sodium bisulphite solution while ensuring complete SO2 removal. This new process is characterized by a double absorption strategy at two different pH levels. The first step, at an acidic pH, generates the desired bisulphite solution, while the second step, at a basic pH, produces the sulphite solution for recycling into the first step and ensures total SO2 removal. The process’s performance and feasibility were evaluated on a laboratory scale using a batch reactor with synthetic gas. The parametric study focused on the initial sulphite concentration in the absorption solution and the reactor temperature. A removal efficiency exceeding 95% was achieved across all initial sulphite concentrations and temperature ranges, when the pH was maintained above 6. At pH 5, where bisulphites are the predominant sulphur species, the removal efficiency remained substantial at approximately 70%. The oxidation of sulphites/bisulphites by oxygen in the flue gases was minimal, with less than 5% conversion to sulphate. Additionally, pH-controlled experiments were conducted to optimize plant start-up procedures. For the basic reactor, starting with water and adjusting the pH to 8 during SO2 absorption effectively minimized sodium hydroxide consumption. In contrast, for the acidic reactor at pH 5, initiating the process with a concentrated sulphite solution resulted in more stable absorption rates. These findings underscore the process's potential for efficient sulphur recovery and highlight the importance of pH management in optimizing operational stability and chemical consumption.

Environmental performance of three innovative leather production processes using less chromium and water

Leather production contributes positively to economic developments but can create severe environmental impacts, due to the associated consumptions of water and chemicals. The substance of main concern is the basic chromium sulphate, widely used as tanning agent, which provides high-technical performance to the finished leather. This study quantifies the environmental sustainability of a conventional leather production process and those of three innovative processes, characterised by limited consumptions of chromium and water. Standardised life cycle assessments were implemented, with reference to the production chains starting from pickled skins until the production of two finished leathers (for goods and footwear), having the same technical and aesthetic characteristics of those from the conventional process. The innovative tanning processes adopt conventional rotating drums or substitute them with spray nozzles or aerosol rooms, and require a specific pre-treatment that includes de-pickling, drying and stabilisation of input skins. Tests at industrial scale (or at pilot scale for the solution with aerosol rooms) indicate that the new processes strongly reduce impacts in terms of Human toxicity-cancer, Ecotoxicity freshwater and Resource use-minerals and metals (up to 57 %, 29 % and 48 %, respectively) even though they imply an increase in terms of Climate Change (up to 51 %). Losses of chromium in wastewater and solid waste are reduced from >33 g/m2finished leather, for the conventional process, to about 8 g/m2finished leather, 5 g/m2finished leather, and 1 g/m2finished leather, for the innovative processes.The environmental sustainability of the proposed new processes increases from the solution with drums (and less water and chromium) to that utilising spray nozzles and aerosol rooms. A great improving can be obtained even just with the “simple” new drum solution, able to reduce the Human toxicity-cancer potential up to 53 % and Resource use-minerals and metals potential up to 42 %.

COCOFUEL: A Microcontroller-Based Biodiesel Production Machine

In the global landscape, the coconut stands out, with over 61 million tons harvested annually, yielding approximately 75 coconuts per tree annually. Recognizing its multifaceted benefits, including its suitability as a biofuel, various countries have endeavored to develop biodiesel production machines, each employing distinct methodologies and chemical compositions. Central to these efforts has been the drive to optimize production efficiency while minimizing costs, encompassing chemical inputs, procedural complexity, and energy consumption. This project undertook the design and implementation of a microcontroller-based machine tailored exclusively for biodiesel production via the transesterification method, utilizing coconut oil, methanol, and a catalyst. Adopting the Rapid Application Development framework, the project unfolded through iterative cycles, encompassing analysis, design, prototyping, testing, and refinement. The machine’s core functionalities were orchestrated by the Arduino Mega microcontroller, orchestrating the operation of washer motors, solenoid valves, and the heating rod, complemented by a relay, Bluetooth module, and voltage regulator. Thorough testing and evaluation underscored the machine’s reliability and efficacy in producing biodiesel from coconut oil, marking a significant stride toward renewable en ergy advancement. This accomplishment not only heralds progress in green energy solutions but also offers a compelling response to the environmental imperatives associated with conventional diesel fuels. The potential for reduced carbon emissions and the promotion of environmental sustainability amplifies the significance of this development, charting a course toward a greener future through the synergy of natural resources and cutting -edge technology.

Efficiency improvement of wastewater treatment plants under the background of “double carbon”: a case study in Jiujiang city, China

Wastewater treatment plants (WWTPs) play a crucial role in modern urban water environmental protection. However, they face challenges related to high operational costs and carbon emissions. This study focused on addressing these issues through an analysis of four urban WWTPs in Jiujiang city, China. The study involved comparing the size and processes of the plants, evaluating influent and effluent water quality, assessing energy consumption and chemical usage, and calculating both direct and indirect carbon emissions. The results demonstrated that the high operational costs and increased carbon emissions in these WWTPs were primarily attributed to low hydraulic loadings, low influent concentration, and high energy and chemical consumption. In response, three targeted scenarios were proposed to enhance the efficiency of the WWTPs and reduce carbon emissions. These scenarios involved adjusting the amount of wastewater imported into the WWTPs to meet the designed capacity, optimizing operating costs, or combining both approaches. Among the scenarios, Scenario 3 emerged as the most effective in terms of improving efficiency and reducing carbon emissions. The operational costs for WWTPs could be reduced in the range of 0.42–1.04 RMB/m3, representing a reduction rate of 35%–57%. Additionally, carbon emissions could be lowered from 15.02 to 598.85 gCO2e/m3, corresponding to a reduction of 2.91%–41.38%. Although Scenario 2 exhibited a lower carbon emission reduction of 14.8–316.33 gCO2e/m3, it was identified as the most feasible and easily implementable high-efficiency solution at present, with a reduction in operational costs ranging from 0.43 to 1.31 RMB/m3. To achieve zero energy consumption and zero carbon emissions in wastewater treatment in the future, it is recommended to undertake additional measures, such as enhancing dosing system accuracy, implementing tail gas collection, adopting photovoltaic power generation, implementing carbon sequestration techniques, and exploring wastewater heat source recycling. These findings provide valuable insights for optimizing the operational efficiency of urban WWTPs, reducing carbon emissions, and promoting sustainable wastewater treatment practices in Jiujiang city, China.

Recycle of spent LiFePO4 batteries: An eco-friendly closed-loop technique based on less solvent solid state reaction

Lithium iron phosphate (LFP) batteries have become one of the most popular batteries due to their high safety and low cost. However, the lifespan of LFP batteries is limited, making effective recycling processes crucial for environmental protection, resource conservation, and economic benefits. Less solvent solid state reaction (LSR) is reactions of solids with the help of a little solvent, which has advantage of almost 100% conversion of reactants and no waste generation. Herein, LFP (S-LFP) from spent batteries was first entirely decomposed to produce FePO4 and LiH2PO4 in H3PO4-H2O2 leaching systems using the LSR method. Then, battery-grade Li2CO3 was prepared by adding CaCl2 and Na2CO3 to LiH2PO4. As a result, the battery of regenerated LiFePO4 (R-LFP) using recycled FePO4 and Li2CO3 exhibits superior electrochemical performance compared to those with unused LiFePO4, including a higher discharge specific capacity (140.7 mAhg−1 at 0.1C) and excellent cycle life, with a capacity retention of 98.6% over 500cycles at 1.0C. The LSR method provides a green and sustainable closed-loop recovery strategy for S-LFP cathode materials, which reduces the number of processing steps and chemical consumption, promotes resource conservation and environmental protection, and facilitates the sustainable industrial development of S-LFP batteries.