Key Takeaways & Executive Findings
- •• • Oil spill diffusion distance and affected area are predominantly governed by water conditions and emergency resource accessibility; in high-water months, the efficiency of maintenance and repair resources is critical, as response time directly influences containment success. • • External forces (hydraulic and wind) dominate oil spreading over internal forces (gravity, inertia, viscosity, surface tension) within short timescales; for long emergency resource arrival times, internal force contributions based on Fay's theory are negligible, simplifying simulation models. • • The study designed eight scenarios combining two leakage modes (small hole and full rupture), two water conditions (high and low flow), and two emergency resource locations (operation area and maintenance center), enabling comprehensive risk assessment. • • The simulation framework integrates leak rate calculations (pressurized and unpressurized), oil volume estimates, and diffusion distance models, providing a practical tool for rapid assessment of spill impacts and resource allocation.
Abstract
With the increasing number of oil pipelines crossing rivers, the potential risks of oil leakage and surface spreading to river ecosystems and water environments are becoming more severe. Scenario-based simulation of oil spill diffusion is a prerequisite for effective interception point placement and leakage risk prevention. Numerous factors influence oil spill diffusion, including environmental conditions, river hydrology, and accessibility of emergency resources. This study integrates these factors and multiple dynamic processes to design eight typical scenarios for oil spill diffusion simulation, considering emergency resource locations, river hydrological regimes, and leakage modes. A case study is conducted on an oil pipeline crossing a river in northwest China. Results indicate that the diffusion distance and affected area are primarily controlled by water conditions and emergency resource accessibility. In emergency management, the efficiency of maintenance and repair resources during high-water months should be prioritized. Mechanistically, external forces such as hydraulic and wind forces have a greater influence on diffusion distance, surpassing internal forces like gravity, viscosity, and surface tension within a short time. For river crossings near emergency resources, internal force effects should be considered in oil spill diffusion simulations. When emergency resource arrival times are long, the diffusion distance based on Fay's theory is relatively small and can be neglected in engineering practice. This study provides a computational basis and methodological reference for risk assessment and emergency response to potential oil spills from pipelines crossing rivers, enhancing the scientific and effective nature of risk prevention and emergency handling.
1. Introduction
Oil pipelines are vital arteries for energy transport, yet their crossings of rivers pose significant environmental risks. Aging infrastructure, corrosion, and third-party damage can lead to leaks, contaminating water resources and threatening ecosystems. Existing numerical models for oil spill simulation, primarily developed for marine environments, often fail to capture the unique constraints of river crossings, such as strong bank confinement and high variability in flow velocity between wet and dry seasons. Moreover, these models typically focus on oil transport dynamics without considering the practical response logistics, such as the time required for emergency resources to reach the spill site. This gap hinders effective risk assessment and emergency planning for pipeline-river crossings.
To address these bottlenecks, this study proposes a scenario-based simulation framework that integrates key controlling factors: leakage mode, river hydrology, and emergency resource accessibility. By designing eight representative scenarios, the framework accounts for both typical and worst-case conditions, enabling a comprehensive evaluation of oil spill diffusion. The methodology simplifies complex physical processes into practical calculations, balancing accuracy with operational efficiency. A case study on a pipeline crossing a river in northwest China demonstrates the framework's utility, revealing that water conditions and response time are the dominant factors influencing spill extent. This approach provides a scientific basis for optimizing emergency resource deployment and enhancing the effectiveness of oil spill response in riverine environments.
Loading authentic research manuscript (Pages 1–5)...
LIU Yuanwen, QU Jing, LIU Xiang, WANG Jiuping, WANG Shengxin, WANG Yifei, GAO Zuqiao, LYU Yu, LI Changbin (2026). Scenario Simulation and Case Study of Oil Spill Diffusion from Oil Pipelines Crossing Rivers. Chinese Journal of Environmental Engineering. https://doi.org/10.12030/j.cjee.202511020
Research & Educational Purpose Only: The translations, structured abstracts, analytical annotations, and data reports provided by SinoGreenTechare intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoGreenTech claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
How does the simulation framework account for the transition from pressurized to unpressurized leakage after valve closure?
The framework models two distinct phases: pressurized leakage from leak detection to valve closure, using a simplified orifice equation with a discharge coefficient dependent on Reynolds number and crack shape; and unpressurized leakage after valve closure, where the leak rate is governed by the static head of the remaining oil in the pipeline. The total spill volume is the sum of both phases, with the unpressurized phase continuing until the available oil volume is depleted.
What are the key parameters influencing the diffusion distance, and how are they prioritized in the model?
The diffusion distance is primarily influenced by water flow velocity, wind speed, and the time for emergency resources to arrive. The model calculates internal spreading using Fay's three-stage theory (gravity-inertia, gravity-viscous, and surface tension-viscous) and external drift due to water and wind. In scenarios with long response times, external forces dominate, and internal spreading can be neglected, simplifying calculations.
How does the model handle the variability in river hydrology between wet and dry seasons?
The model considers two representative water conditions: high flow (wet season) and low flow (dry season), using the most unfavorable conditions for each. Flow velocity is estimated using Manning's equation with riverbed roughness and hydraulic radius, allowing the model to capture the impact of seasonal variations on oil spill diffusion.
What is the practical significance of the eight scenarios in emergency planning?
The eight scenarios combine two leakage modes (small hole and full rupture), two water conditions (high and low flow), and two emergency resource locations (operation area and maintenance center). This matrix allows emergency planners to assess the range of potential spill extents and response times, facilitating the design of tailored interception strategies and resource allocation for different risk levels.
How does the model validate its accuracy against real-world incidents?
The model was applied to a case study of an oil pipeline crossing a river in northwest China. The simulation results were compared with historical data and expert judgment, demonstrating that the predicted diffusion distances and affected areas align with observed patterns. However, the paper does not provide quantitative validation metrics, indicating a need for future field experiments or historical incident data to further refine the model.
Related Chinese Research & Cross-Citations
Analysis of National and Local Policies for Medical Waste Treatment and Disposal in China
The escalating generation of medical waste, driven by healthcare expansion and frequent medical activities, poses significant environmental and public health risks. Under the framework of ecological civilization, China is developing a comprehensive policy system for medical waste treatment and disposal, yet the current framework remains nascent and exhibits inconsistencies between national and local policies. This study systematically analyzes the status of national and local policies from 2003 to 2024, collecting 413 policy documents (166 from national ministries and 247 from provincial governments). The analysis examines temporal evolution, regional distribution, and policy focus, alongside the influence of medical waste output, treatment technologies, facility infrastructure, and major epidemic responses. Findings reveal distinct policy phases: initial self-disposal, exploratory management, foundational system building, and rapid development. Regional disparities are pronounced, with eastern coastal areas showing more advanced policies due to greater technical and financial resources. The surge in medical waste, particularly during the COVID-19 pandemic, underscores the need for enhanced regulatory guidance. Non-incineration technologies are gaining traction for their environmental and cost benefits, and facility coverage has improved but remains uneven. The study proposes five policy principles to foster technological innovation and industrial upgrading, ensuring safe medical waste management and environmental protection.
Kinetic Analysis and Simulation of Pollutant Removal in Sewage Networks
This study investigates pollutant removal characteristics and kinetic behaviors in sewage networks, and analyzes their impact on the carbon-to-nitrogen ratio (C/N, as COD/TN) of influent to wastewater treatment plants. Source water quality sampling at drainage outlets revealed spatial and temporal variations in C/N, with domestic sewage exhibiting higher C/N than industrial sewage, and diurnal peaks reaching 6.92 versus 4.71 during off-peak hours. Using a pilot-scale adjustable sewage network system in Kunshan, experiments were conducted under high (0.491 m·s−1) and low (0.089 m·s−1) flow velocities, monitoring pollutant removal over 144 hours. Pseudo-first-order kinetics were applied to model COD and TN removal. Results showed that COD (including SCOD and PCOD), BOD5, and SS achieved approximately 80% removal within 144 h, with higher removal at low flow velocity. TN, NH3-N, and TP exhibited lower overall removal rates. Kinetic fitting revealed that COD removal rate constants (kCOD) were significantly higher than those for TN (kTN), and both decreased with increasing flow velocity: at low velocity, kCOD=0.0167 h−1 and kTN=0.0029 h−1; at high velocity, kCOD=0.0127 h−1 and kTN=0.0020 h−1. Simulations based on actual source pollutant concentrations indicated that the time for C/N to drop to the denitrification critical value of 4.50 was 12.24 h at high velocity, but shortened to 9.49 h at low velocity. These findings demonstrate that increasing flow velocity effectively retards the decline of C/N. Therefore, regulating network flow velocity to reduce hydraulic retention time is a key strategy for maintaining adequate C/N at the terminal and ensuring denitrification efficiency in wastewater treatment plants.
Preparation of Trimetallic-Carbon Composite Catalysts and Their Application in Catalytic Ozonation of Industrial Wastewater
Advanced oxidation processes (AOPs) are promising for degrading organic pollutants in water treatment. Heterogeneous catalytic ozonation (HCO) has gained attention due to its high oxidation efficiency, strong interference resistance, and low secondary pollution. In this study, a series of trimetallic-carbon composite ozone catalysts were prepared via an organic precursor calcination method using γ-Al2O3 as support. This method enhanced catalytic activity and mechanical strength while overcoming the limitations of carbon materials (low mechanical strength) and metal-based materials (poor mass transfer). The optimized catalyst, CA-FeCoCu, comprising Fe, Co, Cu, carbon, and alumina, exhibited excellent performance in phenol degradation and real industrial wastewater treatment. Characterization revealed that the synergistic effect of trimetals and the introduction of multiple carbon types increased specific surface area and hydroxyl radical (·OH) generation. In a pilot-scale fixed-bed reactor, the CA-FeCoCu/O3 system reduced COD from 120 mg·L−1 to below 40 mg·L−1, with an O3 consumption ratio (O/C) of less than 1, effectively lowering operational costs. This work provides a new strategy for developing efficient and stable heterogeneous O3 catalysts and offers a reference for the practical application of HCO in industrial wastewater treatment.
Differentiated Characteristics of Suspended Particulate Matter and Their Effects on Water Quality in the Middle and East Routes of the South-to-North Water Diversion Project
This study investigates the spatiotemporal differentiation of suspended particulate matter (SPM) characteristics, sources, and their impacts on water quality between the Middle Route (closed artificial channel) and East Route (open natural water system) of the South-to-North Water Diversion Project. Thirty sampling sites (13 on the Middle Route, 17 on the East Route) were established, and samples were collected during dry and wet seasons. Water quality parameters and SPM characteristics were analyzed, including particle size distribution, total suspended solids (TSS), chlorophyll a, and stable carbon and nitrogen isotopes. Results show that the Middle Route maintains good and stable water quality, with SPM dominated by coarse particles (>63 μm, 61.43%–94.68%), total phosphorus (TP) <0.01 mg·L−1, and a significant positive correlation between chlorophyll a and coarse particles (r=0.60), indicating algal aggregation dominates particle formation. In contrast, the East Route exhibits high and fluctuating nitrogen and phosphorus concentrations, with SPM dominated by fine particles (<20 μm, 51.26%–88.61%), TP ranging from 0.03 to 1.11 mg·L−1, and a positive correlation with fine particles, suggesting significant external inputs. Carbon and nitrogen isotope analysis reveals that Middle Route SPM primarily originates from autochthonous algae (contribution >46.75%), while East Route SPM is influenced by both terrestrial C3 plants and algae. The distinct engineering and management approaches of the two routes lead to significant differences in SPM characteristics and sources, thereby affecting water quality dynamics. The Middle Route requires an 'algal reduction and hydrodynamic optimization' strategy to control algal-derived coarse particle deposition, whereas the East Route benefits from 'retention-sedimentation and wetland purification' to reduce external fine particles and pollutant inputs. This research provides theoretical support and practical guidance for differentiated SPM management in long-distance water diversion systems.
Combined Ozone Micro-Nano Bubble Oxidation and Powdered Activated Carbon Adsorption for Removal of Taste and Odor Compounds from Drinking Water
Algal-derived taste and odor compounds (2-methylisoborneol, 2-MIB, and geosmin, GSM) in drinking water sources are poorly removed by conventional treatment. This study systematically evaluated the standalone and combined performance of ozone micro-nano bubbles (O3-MNBs) oxidation and powdered activated carbon (PAC) adsorption for removing 2-MIB, GSM, and algal cells from source water. Results showed that O3-MNBs pre-oxidation achieved >97.5% removal of odorants at 400 ng·L−1 and 67.2% algal cell removal within 30 min. When applied as a deep treatment stage, the degradation rate constant (k) was 10.1%–25.6% higher than in pre-oxidation due to lower background matrix interference. Both pre-oxidation and deep treatment reduced effluent concentrations of 2-MIB and GSM to below 10 ng·L−1, with oxidation kinetics fitting pseudo-first-order models (R²>0.95). PAC adsorption of both compounds followed pseudo-second-order kinetics (R²>0.99), with GSM equilibrium adsorption capacity approximately 20.0% higher than that of 2-MIB. In pure water, adsorption capacity increased by >10.0% compared to raw water. Based on kinetic models, a quantitative prediction method was established for O3-MNBs oxidation and PAC adsorption processes, aiming to achieve efficient odorant removal and cost optimization, providing theoretical support for advanced drinking water purification and smart water plant construction.
Pulsed Electric Field Enhancement of Nitrogen Removal Performance and Microbial Community Structure Response in Anammox Granular Sludge
This study investigated the effects of a ring-shaped pulsed electric field (PEF) (1.5 V, 4 h on-time per cycle) on nitrogen removal performance and microbial community structure of anammox granular sludge (AnGS). Two anaerobic sequencing batch reactors (R1 control, R2 with PEF) were operated under stepwise increasing nitrogen loading rates (NLR). At NLR below 1,155 mg·(L·d)−1, R2 exhibited total nitrogen removal efficiency (TRE) 7.5%–17.0% higher than R1, with biomass, specific anammox activity (SAA), and extracellular polymeric substances (EPS) increased by 5%–7%, 21%–71%, and 54%–77%, respectively. However, at NLR above 1,320 mg·(L·d)−1, the toxic effect of nitrite dominated, and PEF enhancement diminished or even reversed to inhibition. Microbial community analysis revealed that at low-to-moderate NLR, PEF increased the relative abundance of Planctomycetes and key anammox bacteria (Candidatus Brocadia and Candidatus Jettenia), along with enhanced community richness (Chao1) and diversity (Shannon/Simpson indices). At high NLR, PEF decreased microbial richness compared to R1. Principal component analysis and redundancy analysis indicated that PEF was the key factor driving community differences at low-to-moderate NLR, whereas nitrite concentration became the dominant factor at high NLR. This study provides theoretical support for enhancing the resilience and engineering application of anammox processes.