【目的】目前，我国已经形成了深度脱水-填埋、好氧发酵-土地利用、厌氧消化-土地利用、干化焚烧-建材利用这4条主流的市政污泥处理处置工艺路线，每种工艺路线都有各自的优缺点和适用条件，但每种路线的碳排放水平尚不明确，致使碳排放难以作为工艺比选测算指标落地应用。【方法】根据联合国政府间气候变化专门委员会指南，采用排放因子法，在确定核算边界后，全面核算了污泥从污水处理厂外运直至最终消纳的全流程碳排放量，包括处理处置过程中因甲烷(CH 4)和一氧化二氮(N 2O)释放所产生的碳排放，因电耗、药耗、能耗、运输等所产生的碳排放，以及资源能源替代所产生的碳减排，然后基于该核算结果探讨了污泥处理处置碳减排路径。【结果】污泥深度脱水-填埋、好氧发酵-土地利用、厌氧消化-土地利用、干化焚烧-建材利用的碳排放强度分别为1 465.75、933.46、880.35、752.33 kg CO 2/(t DS)。【结论】通过对比发现，在相同核算边界下，干化焚烧-建材利用是碳排放最少的污泥处理处置工艺，在新建项目工艺比选时可优先考虑。此外，当污泥因适用条件或处置方法受限，必须采用某种工艺时，还可从污泥源头减量、关键技术参数优化、资源能源回收等方面实现碳减排。
Sewage collection and disposal systems. Sewerage, Water supply for domestic and industrial purposes
Drinking water quality and safety are vital factors for public health, and the consumption of contaminated water is one of the main causes of microbial disease transmission. Effective and reliable water disinfection methods at the point of use, especially at the household scale, play an important role in reducing such diseases. This study was conducted with the aim of designing and comparing the performance of four different UVC-LED reactor models for point-of-use water disinfection. To achieve this, Computational Fluid Dynamics was employed to simulate the flow field, mass transfer, and radiation field within the reactors, enabling a detailed assessment of UV distribution and its interaction with the flowing water. In the reactor designs, the influence of internal wall material-specifically polytetrafluoroethylene with diffuse reflectivity and aluminum with specular reflectivity-was investigated to evaluate how surface reflectivity impacts disinfection performance. The results demonstrated that the highest log reduction of Escherichia Coli and the most efficient microbial removal occurred in Reactor Type 4 with an aluminum inner surface, achieving a log reduction of 1.64 and a disinfection efficiency of 30.6%. The findings highlighted that both the reactor geometry and wall material play critical roles in ensuring uniform radiation distribution and enhancing overall disinfection effectiveness. This study offers valuable insights and practical guidance for the optimal design of UVC-LED reactors intended for household and point-of-use applications.
Technology, Water supply for domestic and industrial purposes
Classical swarm models, exemplified by the Cucker--Smale framework, provide foundational insights into collective alignment but exhibit fundamental limitations in capturing the adaptive, heterogeneous behaviours intrinsic to living systems. This paper formalises the mathematical theory of \textit{Behavioural Swarms}, a comprehensive framework where each particle's state incorporates a dynamic internal variable, the \textit{activity} that co-evolves with position and velocity through nonlocal interactions. We demonstrate how this approach transcends prior models by integrating adaptive decision-making mechanisms and heterogeneous behavioural states into rigorous differential systems. Through applications in behavioural economics and crowd dynamics, we establish the theory's capacity to predict emergent macroscopic patterns from individual behavioural states. Our critical analysis positions this framework against kinetic theories of active particles and agent-based approaches, revealing distinct advantages for modelling systems where individual agency drives collective outcomes.
Zahra Ahmadi Panah, Reyhaneh Dehghan, Mehran Bijari
et al.
Photocatalytic technology offers novel solutions for wastewater treatment using visible light. Graphitic carbon nitride, as a polymeric semiconductor, has attracted significant attention in this field. However, overcoming the limitations of this material remains a major challenge for researchers. In this study, a graphitic carbon nitride photocatalyst was synthesized using a thermal polymerization method with melamine as a precursor in a new gaseous atmosphere of CO2. For comparison, similar samples were synthesized in common atmospheres such as N2 and air. The structure, morphology, and properties of the samples were characterized using various analyses. Additionally, considering the importance of E.Coli bacteria, their antibacterial activity against this bacterium was evaluated under both light and dark conditions. The sample synthesized in the CO2 atmosphere had a surface area approximately 3 and 2 times higher than those synthesized in air and nitrogen atmospheres, respectively. Also, the luminescence intensity of this sample was significantly lower, indicating an improvement in photocatalytic performance. The results of microbiological tests showed that the CN-CO2 sample completely inactivated E.Coli bacteria with an initial concentration of 107 CFU/mL when exposed to an effective dose of 0.2 g/L within 180 minutes under visible light irradiation. In contrast, the CN-air and CN-N2 samples inhibited 62.7% and 29.5% of the bacteria, respectively. The results also indicated that CN-CO2 had a high ability to inhibit bacterial growth in the dark. The results of the disk diffusion assay and bacterial viability tests in solid media also confirmed these findings. Given the significant advantages of this nanomaterial (CN-CO2), including high photocatalytic activity, strong antibacterial properties, and a simple and one-step synthesis method, it can be used as an efficient photocatalyst for water and wastewater treatment industries.
Technology, Water supply for domestic and industrial purposes
Lukas Schulthess, Tiago Salzmann, Christian Vogt
et al.
Nowadays, cities provide much more than shopping opportunities or working spaces. Individual locations such as parks and squares are used as meeting points and local recreation areas by many people. To ensure that they remain attractive in the future, the design of such squares must be regularly adapted to the needs of the public. These utilization trends can be derived using public data collection. The more diverse and rich the data sets are, the easier it is to optimize public space design through data analysis. Traditional data collection methods such as questionnaires, observations, or videos are either labor intensive or cannot guarantee to preserve the individual's privacy. This work presents a privacy-preserving, low-power, and low-cost smart sensing system that is capable of anonymously collecting data about public space utilization by analyzing the occupancy distribution of public seating. To support future urban planning the sensor nodes are capable of monitoring environmental noise, chair utilization, and their position, temperature, and humidity and provide them over a city-wide Long Range Wide Area Network (LoRaWAN). The final sensing system's robust operation is proven in a trial run at two public squares in a city with 16 sensor nodes over a duration of two months. By consuming 33.65 mWh per day with all subsystems enabled, including sitting detection based on a continuous acceleration measurement operating on a robust and simple threshold algorithm, the custom-designed sensor node achieves continuous monitoring during the 2-month trial run. The evaluation of the experimental results clearly shows how the two locations are used, which confirms the practicability of the proposed solution. All data collected during the field trial is publicly available as open data.
Olga Kozachek, Nikolay Nikolaev, Olga Slita
et al.
In this paper an adaptive state observer and parameter identification algorithm for a linear time-varying system are developed under condition that the state matrix of the system contains unknown time-varying parameters of a known form. The state vector is observed using only output and input measurements without identification of the unknown parameters. When the state vector estimate is obtained, the identification algorithm is applied to find unknown parameters of the system.
In this work, we address the design of tracking controllers that drive a mechanical system's state asymptotically towards a reference trajectory. Motivated by aerospace and robotics applications, we consider fully-actuated systems evolving on the broad class of homogeneous spaces (encompassing all vector spaces, Lie groups, and spheres of any finite dimension). In this setting, the transitive action of a Lie group on the configuration manifold enables an intrinsic description of the tracking error as an element of the state space, even in the absence of a group structure on the configuration manifold itself (e.g., for $\mathbb{S}^2$). Such an error state facilitates the design of a generalized control policy depending smoothly on state and time, which drives the geometric tracking error to a designated origin from almost every initial condition, thereby guaranteeing almost global convergence to the reference trajectory. Moreover, the proposed controller simplifies elegantly when specialized to a Lie group or the n-sphere. In summary, we propose a unified, intrinsic controller guaranteeing almost global asymptotic trajectory tracking for fully-actuated mechanical systems evolving on a broad class of manifolds. We apply the method to an axisymmetric satellite and an omnidirectional aerial robot.
Red light violation is a major cause of traffic collisions and resulting injuries and fatalities. Despite extensive prior work to reduce red light violations, they continue to be a major problem in practice, partly because existing systems suffer from the flaw of providing the same guidance to all drivers. As a result, some violations are avoided, but other drivers ignore or respond inappropriately to red light running systems, resulting in safety issues overall. We show a method of providing accurate warnings to individual drivers to avoid the broad guidance approach of most existing systems. Recognizing if a driver will run red lights is highly dependent on signal phase and timing, traffic conditions along the road, and individual driver behaviour, the proposed warning system contains three parts: a traffic prediction algorithm, an individual warning signal optimizer, and a driver warning display. The traffic prediction algorithm predicts future traffic states along the road towards the signalized intersections using the latest traffic conditions obtained through vehicle-to-vehicle and vehicle-to-infrastructure communications. Then, an optimization problem is formulated to compute the optimal warning signal based on predicted traffic states and driver reaction model. Finally, the optimal warning signal is shown on the display screen to advise driver on how much braking is needed to avoid running the red light. The system continuously updates the latest warning signal as the vehicle is approaching the intersection. Both numerical simulated driving scenarios and real-world road tests are used to demonstrate the proposed algorithm's performance under different conditions by comparing with previous work on red light running warning system. The results show that the system provides more effective and accurate warning signals to drivers, helping them avoid running red lights.
We associate parametric classes of $n$-component Lotka-Volterra systems which admit $k$ additional linear Darboux polynomials, with admissible loopless hypergraphs of order $n$ and size $k$. We study the equivalence relation on admissible hypergraphs induced by linear transformations of the associated LV-systems, for $n\leq 5$. We present a new 13-parameter 5-component superintegrable Lotka-Volterra system, i.e. one that is not equivalent to a so-called tree-system. We conjecture that tree-systems associated with nonisomorphic trees are not equivalent, which we verified for $n<9$.
Maedeh Parichehre, Fardin Sadeghzadeh, Bahi Jalili
et al.
The increase of various industries and the growth of the earth's population have caused various types of contamination in the environment. Anionic contaminants are one of the most important contaminants in water, which have many risks to human health and living organisms and also have many important environmental risks. Therefore, it is important to modify these resources. Studies showed that the use of biochar and metal-coated biochar effectively leads to the removal of a significant amount of contaminants from water and soil, but so far, the effect of carbon-metal composite on the removal of contaminants, especially anionic contaminants, has not been comprehensively investigated. In this research, the effect of biochar, metal-coated biochar and biochar-metal composite on the removal of chromium from water was investigated. Metal-coated biochars and various biochar-metal composites were prepared from the combination of metals (copper, iron and aluminum) with agricultural residues (rice straw) in raw form or as a biochar. The samples included Biochar, Copper-coated biochar, Aluminum-coated biochar, Iron-coated biochar, Copper composite, Aluminum composite, and Iron composite. In the first stage, the optimal conditions for contaminant removal were investigated, then an optimal amount of adsorbents and contaminant with a concentration of 20 mg/L and pH=6 were combined and shaken for three hours. until they reached equilibrium. After centrifugation and filtration, the final concentration of the contaminant was read and the chromium removal percentage was calculated. The results of the present research showed that the application of iron composite and iron-coated biochar could remove 90.32 and 93.71 percent of chromium pollutant from the aqueous solution, respectively. Therefore, the use of these adsorbents can remediate chromium-contaminated water.
Technology, Water supply for domestic and industrial purposes
A new definition of discrete-time negative imaginary (NI) systems is provided. This definition characterizes the dissipative property of a zero-order hold sampled continuous-time NI system. Under some assumptions, asymptotic stability can be guaranteed for the closed-loop interconnection of an NI system and an output strictly negative imaginary system, with one of them having a one step advance. In the case of linear systems, we also provide necessary and sufficient frequency-domain and LMI conditions under which the definition is satisfied. Also provided is a simple DC gain condition for the stability results in the linear case.
Jacopo Piccini, Elias August, Sigurdur Hafstein
et al.
In this paper, we present a novel approach to determine the stability of switched linear and nonlinear systems using Sum of Squares optimisation. Particularly, we use Sum of Squares optimisation to search for a Lyapunov function that defines an absorbing set that confines solution trajectories. For linear systems, we show that this also implies global asymptotic stability. Using this approach, we can study stability for a broader range of switched systems, particularly, we can search for a global attractor for switched nonlinear systems, whose dynamics are given by polynomial vector fields and which have multiple equilibria or limit cycles.
The paper suggests a generalization of the Sign-Perturbed Sums (SPS) finite sample system identification method for the identification of closed-loop observable stochastic linear systems in state-space form. The solution builds on the theory of matrix-variate regression and instrumental variable methods to construct distribution-free confidence regions for the state-space matrices. Both direct and indirect identification are studied, and the exactness as well as the strong consistency of the construction are proved. Furthermore, a new, computationally efficient ellipsoidal outer-approximation algorithm for the confidence regions is proposed. The new construction results in a semidefinite optimization problem which has an order-of-magnitude smaller number of constraints, as if one applied the ellipsoidal outer-approximation after vectorization. The effectiveness of the approach is also demonstrated empirically via a series of numerical experiments.
Elnaz Bakhshi Sarabi, Mohammad Reza Allahgholi Ghasri, Ali Parsa
The discharge of wastewater from various industries such as petroleum and petrochemical, pollute water resources. The presence of these pollutants in water resources will cause disorders in the ecosystem and it has various risks to human health. The effluent usually contains organic matter, including phenol and its derivatives. In this study, three different types of reactors were used in the activated sludge process to study the biological removal of o-nitrophenol from the petrochemical industrial effluent. These reactors include Continuous Moving-Bed Sequencing Batch Reactor, Moving-Bed Sequencing Batch Reactor and conventional sequencing batch reactor. For this purpose, the operational indicators of each reactor were investigated and optimized. For MSBR, active sludge volume ratio (30%), aeration flowrate (18 L/min), operation time (4h), pH (7), filler to reactor volume ratio (4.7 %) and SVI (89 ml/g) were considered. Also, For C-MSBR indicators such as initial volumetric flowrate (20 ml/min), aeration flowrate (12 L/min), filler to reactor volume ratio (5.8 %) and SVI (98 ml/g) were optimized. As SBR is structurally similar to the other reactors, only initial volumetric flowrate was considered (40 ml/min) and based on the results, this reactor has better SVI (88 ml/g) than the other two reactors. Finally, based on the optimized parameters, percentage removal of ortho nitrophenol from a synthesized effluent, analogous to Karoon Petrochemical company effluent, was investigated by C-MSBR. In addition to o-nitrophenol, other chemicals such as Toluene and Benzene were also present. The results show the indicators including ortho nitrophenol percentage removal (84.7%), Chemical Oxidation Demand (COD) (94%), Biochemical Oxidation Demand (94.8%), BOD5/COD (0.57) and SVI (74.45 ml/g) comply with environmental standards and the treated effluent can be used in irrigation and agriculture by addition of one more processing step.
Technology, Water supply for domestic and industrial purposes
In this paper we derive fundamental limitations on the levels of $H_2$ and $H_\infty{}$ performance that can be achieved when controlling lossless systems. The results are applied to the swing equation power system model, where it is shown that the fundamental limit on the $H_2$ norm scales with the inverse of the harmonic mean of the inertias in the system. This indicates that power systems may see a degradation in performance as more renewables are integrated, further motivating the need for new control solutions to aid the energy transition.
Afarin Ekbatani, Amirhesam Hasani, Amir hossein Javid
One of the hazardous compounds for humans and the environment is polycyclic aromatic hydrocarbons, which are the naphthalene of the precursor of two-ring aromatic hydrocarbons. These compounds are carcinogenic and toxic, they cause anemia and damage to the retina and are also toxic to plants and aquatic animals, these compounds have been identified as priority pollutants by the World Health Organization, yet these compounds are difficult to remove by biological methods. This study was performed in batch in vitro where the effect of parameters such as retention time 15, 30, 45, 60, 90 and 120 minutes, concentration of multi-walled carbon nanotubes and activated carbon from coconut skin 0.1, 0.25, 0.5, 0.75, 1 and 2 g/L), solution concentration 1, 5, 10, 15, 20, 50 and 100 mg/L and pH 3, 4, 5, 6, 7 and 8 the concentration of 10 mg/L naphthalene solution in naphthalene removal was investigated. Experimental data of adsorption equilibrium with different Langmuir and Freundlich adsorption isotherm models are evaluated and analyzed with adsorption kinetics by comparing R2 coefficient of analysis and analyzed by excel software. Maximum naphthalene adsorption on both carbon nanotubes and activated carbon nanotube adsorbent at initial concentration of 10 mg/L naphthalene and adsorbent dose equal to 0.75 g/L at pH=7 is an appropriate time to achieve maximum naphthalene adsorption;the balance mode is 90 minutes. The adsorption mechanism is consistent in both adsorbents of Langmuir adsorption isotherm and their coefficient of determination in carbon nanotubes is (R²=0.9589) and in coconut shell activated carbon (R²=0.9319). and both adsorbents are from adsorption synthetics second-degree followers. Multiwalled carbon nanotubes and activated carbon from coconut skin due to their small size, high cross-sectional area as a result of high reactivity, as an adsorbent for removal of naphthalene from water. And the nanotube has a higher absorption than activated carbon from the coconut skin, so it is considered as a better adsorbent because of its affordability and availability.
Technology, Water supply for domestic and industrial purposes
Mathematical models are essential to analyze and understand the dynamics of complex systems. Recently, data-driven methodologies have got a lot of attention which is leveraged by advancements in sensor technology. However, the quality of obtained data plays a vital role in learning a good and reliable model. Therefore, in this paper, we propose an efficient heuristic methodology to collect data both in the frequency domain and time-domain, aiming at the best possible information gain from limited experimental data. The efficiency of the proposed methodology is illustrated by means of several examples, and also, its robustness in the presence of noisy data is shown.
Abstract: The configuration of logistics networks for waste oil and fats collection services is a strategic point of great importance, since their disposal contributes to a number of environmental disturbances, problems in sewage pipes and wastewater treatment systems. Starting from this premise, this paper proposes location of ecopoints in the city of Montes Claros-MG, capable of optimizing the collection of the waste oil and fats in all urban area of the municipality. This proposal of location was constructed in two stages: in the first, the collection network was constructed by integrating a location model of facilities with a geographic information system (GIS). It was possible to model a collection network in the city of Montes Claros - MG containing 87,748 points referenced by geographic coordinates and representatives of residential points considered as potential generators of these residues. During the creation of the model, due to the high density of the network and the low quantity of facilities (p), which causes limitation in the solution, it was observed the need for thematization of the map and consequently the network partitioning in zones, which allowed to determine the initial amount of installations that were to be found in the solution. Finally, an application in the native language of Transcad, GISDK, was developed with a programming interface that was developed to automate the process of integration of the model in the GIS. The model allowed the creation of 12 networks with densities below 12000 points, allowing gain in the solution of the problem.