Sustainable Development of Water and Environment

This work presents a numerical study of solar thermal energy production in DSF applied in the human comfort improvements, in winter conditions. The study considers a solar thermal energy production made in a DSF system placed in the outdoor environment and the improvement of human comfort conditions, namely the thermal comfort and the indoor air quality in a virtual office provided with impinging jets ventilation and occupied by eight occupants seated around the table with eight seats. This study uses a Building Dynamic Response numerical model and coupling of the Computational Fluids Dynamics and Human Thermal Response numerical models. The impinging jets ventilation is built with an inlet system and an outlet system. The inlet system integrates 4 vertical ducts, installed near the corner of the walls, whose airflow direction is descendent, at 0.5 m from the floor. The outlet system integrated six vertical ducts, located above the head level, with ascendant airflow direction. The study considers a solar thermal energy production in DSF during all day and the detailed evaluation of comfort condition in the middle of the morning and afternoon. The indoor air quality, thermal comfort, Draught Risk and Air Distribution Index are evaluated. The results show that the energy production ensures acceptable indoor air quality and thermal comfort conditions.

Depth, width, velocity and suspended load are essential hydraulic features that are determined mainly in the form of the river cross-section. The objective of this study is to measure the hydraulic geometry parameters at station and investigate the relationship between hydraulic geometry parameters with suspended sediment concentration of the Universiti Pertahanan Nasional Malaysia (UPNM) channel. In the analyses on the channel, three stations were selected. All of these stations have sediment discharge, flow discharge and cross-sections measured data. Result shows that at relationship of discharge and hydraulic geometry parameters b, f, m, a, c and k were obtained to be −0.0440, 0.1386, 0.3305, 1.4948, 0.3670 and 0.4868 respectively. While the average hydraulic geometry sediment rating at every station found to be 0.2728, 0.3765, 0.3745, 3.9596, 1.9478 and 1.4601 respectively. Moreover, suspended sediment discharge and flow discharge shows a good average correlation coefficient and exponent of 0.0112 and 2.7031 exponent, respectively. Overall, the results of this research should be useful for watering the basin, management and resource planning projects.

Water is importance to Earth and living things. Human can survive for a few weeks without food but only a few days without water. Clean and safe water is particularly needed as a source of drinking water. It also needs to be used for various purposes, such as domestic and drinking purposes. Solar distillation process is one of the purification technologies that is sustainable and green technology which can be used to resolve the current problem. This paper presents the efficiency of solar still distillation system integrated with 1000 and 2000 W alternating current (AC) immersion water heater to optimize clean water output. Comparison of the amount of water output between the solar still distillation system with 1000 W immersion water heater (SSA) and the solar still distillation system with 2000 W immersion water heater (SSB) was made. The productivity increased about five times when SSB was used compared to SSA. A numerical analysis was performed to verify the results of the experiment. The water production was expected to increase up to 7.50 L/m² per 24 h when using SSB. Therefore, SSB is more effective than SSA to produce distilled water.

This study performs a stability analysis to evaluate the performance of man-made slopes constructed on the UPNM campus. One of the slopes has a steep slope angle and is selected for investigation in this case study to re-examine its stability and prevent any potential hazard to people and nearby structures. The factor of safety (FOS) of the slope is determined using the ordinary method of slices and SlopeW, where the computed FOS is 0.64 and 0.88, respectively. This study did not take into account groundwater level or rock layer and hence it is recommends using soil nailing to enhance the stability of the slope. The results of this study will help local authorities identify the potential failure zone and implement possible remedial measures.

Cost estimating for wastewater treatment plant (WWTP) construction/upgrade projects is a worldwide priority and is useful for forecasting its future economic needs. On the other hand, sensitivity analysis can provide valuable information about design decisions. Nowadays, there is an increasing interest to use membrane bioreactor (MBR) for wastewater treatment. This study intends to analyze and compare the total project construction, operation labor, maintenance labor, material, chemical, energy and amortization costs of the proposed full-scale municipal WWTP configurations consisting of modified Bardenpho (5-stage biological nutrient removal) process with and without MBR for different average influent wastewater flow rates. The designs, theoretical effluents quality and costs comparison of the two WWTP configurations were reported. Results demonstrated that the application of MBR system in WWTP could result in not only higher capital cost but also higher operation and maintenance costs than conventional processes for the same average influent wastewater flow rate. In addition, the costs were enhanced with increasing the average influent wastewater flow rate.

With the rapid development of deepwater petroleum engineering, the waxing characteristics of waxy crude oil have attracted more and more attention. In order to obtain a more accurate wax precipitation point of waxy crude oil, the test methods of wax precipitation point are summarized and compared. The test methods are classified into conventional and unconventional methods. In terms of test conditions and applicability to gas-bearing crude oil, three conventional methods (microscopic observation method, rheometer method, and differential scanning calorimetry method) were compared. It is pointed out that the test conditions should be formulated according to the actual working conditions when the wax precipitation point is determined, and the test method should be selected according to the wax crystal type and wax content. Wax deposition will block the pipeline, thus reducing the transmission efficiency of the pipeline; the residual paraffin deposit in the scrapped pipeline will penetrate into the earth and pollute the environment. Before the pipeline is scrapped, wax removal measures should be taken to remove the paraffin deposit inside, so as to protect the environment. Therefore, the research on paraffin removal and prevention of crude oil is of great significance to the normal production and environmental protection of oil wells.

With the oilfield entering into the late stage of development and production, the difficulty of exploitation is increasing. The passage between the abandoned oil and gas wells and the formation is often caused by the influence of exploitation. There is the possibility of oil and gas leakage, polluting the underground water, and then causing serious environmental pollution accidents. If waste oil wells can be utilized to exploit geothermal energy, safety hazards or leakage problems caused by improper plugging can be solved, and high drilling costs can also be saved. Therefore, built on the current research status. This paper analyzes the feasibility of geothermal energy exploitation of abandoned oil Wells, discusses the retrofit technology of abandoned oil Wells and the related applications of geothermal energy, and gives reasonable suggestions for development.

The numerical simulation presented in this paper is focused on the development of a numerical model used to calculate the evolution of the temperature distribution in a tree trunk when it is affected by the passing of a fire front. The purpose is to assess which points on the tree trunk exceed the tree lethal threshold. Heat conduction inside the trunk tree, heat convection between the tree trunk surface and the air environment and heat exchange by radiation between the trunk surface and the surrounding body surfaces are thermal phenomena considered in the numerical model. The case considered in the numerical simulation is characterized by the propagation of a fire front at a constant fire spread rate from a distance of 5 m upstream of the tree trunk to a distance of 25 m downstream of the tree trunk. The tree trunk has a height of 2 m and a diameter of 0.3 m. The fire front has a flame temperature of 1000 °C, a fire spread rate of 0.01 m/s, a tilt angle of 45°, 10 m wide and 1.2 m high. The results obtained demonstrate that the tissues of the tree trunk located on its surface and in the first layers below its surface will die due to the temperatures calculated there being above the tree lethal threshold.

In order to investigate the organic compounds from sea salt, soluble organic polar fractions as a result of chloroform extraction followed by being esterified with BF₃ in methanol were determined using gas chromatography-mass spectrometry (GC–MS). There were greater than 20 soluble organic polar fractions presented in sea salt, and the major components were C₁₅–C₂₈ fatty acid compounds series, plasticizers and sulfur. The total amount of fatty acids accounted for more than 50%, and C₁₆ was the main peak. The relative abundance of n-hexadecanoic acid was the highest (41.19%) among the soluble organic polar fractions from the analyzed sample. At the same time, a certain amount of phthalate acid esters (PAEs) such as dibutyl phthalate (DBP), diisobutyl phthalate (DIBP) and bis(2-ethylhexyl) phathalate (DEHP) and sulfur (S6, S7 and S8) were detected, and the contents of the two component types were relatively close. Among the three PAEs, the relative abundance of DIBP (17.678%) was the highest. Further, their effects on marine organisms and ecosystem should be concerned based on the potential risks of PAEs.

Wastewater treatment plants (WWTPs) are one of the significant pathways of microplastics (MPs) entering the environment. Thus, information regarding this issue is still requisite in Thailand. In this study, wastewater and sludge samples were collected from an activated sludge operation of an industrial WWTP in different seasons, that is, dry season and wet season. The MP particles were identified by size, shape, and polymer types under stereomicroscope and μFT-IR. From the wastewater, MPs were detected in the highest amounts after the aeration unit (134.35 ± 20.79 particles/L) during dry season and from influent (103.13 ± 59.48 particles/L) during wet season. In addition, sludge contained relatively low MP concentrations (2.27 ± 0.08 in the dry and 1.86 ± 0.28 particles/g dw. in the wet seasons). The size fraction in wastewater varied, but in sludge was > 300 μm commonly in both seasons. Fragments and pellets were identified as the most common shape of wastewater and sludge in both seasons. The treatment units and seasonal variation had a significant effect on MP abundance. The suspected particle was confirmed to be 71.13% plastic polymer, mainly polypropylene (PP) and polyethylene (PE). The overall removal efficiency was 93.86%, indicating that there are many MPs still discharged to the river due to effluent MPs, which was approx. 1.8 × 10⁸ particles per day. Consequently, this study suggests that, to define the effect of a season, prolonged monitoring is required. Moreover, the attention must be on WWTPs in Thailand, as they act as the greatest source of MP contamination in the environment.

Ecosystem services value (ESV) is a direct manifestation of the change of ecosystem service function and benefits. In this study, we evaluated the value of 11 primary ecosystem services in the upper and middle region of Heihe River Basin (UMHRB) from 2000 to 2018. The spatial–temporal heterogeneity was explored at the grid-scale by using ecosystem service value model, and hot spot analysis. The results showed that: (1) The structure of land use in UMHRB was dominated by unused land, followed by grassland, farmland, forestland, water area and built-up land. The change trend of land use was the decrease of unused land and grassland, and the increase of built-up land, water area, farmland and forest land. (2) The temporal evolution of total ESV in UMHRB had shown a steady upward trend from 2000 to 2018. Among the ecosystem types, grassland and water area contributed the most to ESV. The trend of ESV changes showed that the ESV of unused land, grassland and forestland decreased, while the ESV of built-up land, farmland and water increased. For each individual ESV, hydrological regulation and climate regulation had the largest ESV contribution. Only the ESVs of climate regulation have slightly decreased, while other ecosystem services have increased. (3) The spatial distribution of ESV in UMHRB showed a spatially clustered distribution pattern and the degree of clustering was slightly weakened. From 2000 to 2018, the hot spots were mainly distributed in the southern Qilian Mountains, and sporadically scattered near reservoirs and rivers in the northern region. The cold spots were concentrated in the northern part near the desert area.

The permeation of Cr(VI) from acidic media, through a dispersion supported liquid membrane (DSLM), impregnated with tri-n-octylamine (N235) in diluent has been investigated in flat-sheet operational mode. Effects of operational factors including stirring speed, initial Cr(VI) concentration, N235 concentration, NaOH concentration, and the volume ratio of liquid membrane and strip liquor in dispersion phase on Cr(VI) transport have been studied. The evaluation of Cr(VI) separation from hydrochloric acidic media was carried out. Under the optimal condition, the migration rate of 0.01 g/L Cr(VI) was observed as 94%.

The influence of the releasion, migration and transformation of heavy metals in the process of mineral mining on the content of soil components near the mine needs to be studied, and some reliable element determination methods need to be adopted in the research process. Soil samples in 20 mesh (0.850 mm), 40 mesh (0.425 mm), 80 mesh (0.180 mm) and 100 mesh (0.150 mm) from farmland and mining areas of Longnan City in Gansu Province were determined by S1 Titan hand-held X-ray Fluorescence (XRF) spectrometer for understanding factors affecting composition contents determination. Results showed that mesh of samples sieved had a definite impact on determination of heavy metals. Repeatability was greatly affected when samples were in 20 mesh and 100 mesh. Contents of As and Al₂O₃ in samples were easily affected by mesh of sample. It should be concerned that As contents of some soil samples from farmland in Longnan City of Gansu Province were more than 30 mg/kg, contents of metals, sucn as Pb, Zn and As from mining area in Longnan City of Gansu Province were more than 1000 mg/kg. The phenomenon revealed by these measurement data required attention.

A sustainable city does not come from only high technological development in many cases; an area based sustainable development was found in the city with good collaboration between stakeholder within the city. Taken from a case study of haze pollution in Chiang Mai, the government has been dealing with haze in a temporary and short-term manner for over a decade, rather than implementing sustainable solutions. The reoccurrence of haze has caused conflict between the local government and its citizen. The new socially organized group “Breath Council” has sparked a new light and shifted the power to solve haze in Chiang Mai. This is a new space for collaboration and participation between previously conflicted actors. This paper depicts implementing a social collaboration strategy in the institution/relationship arrangement toward sustainable development.

The increasing water demand has been one of the major global issues for the past decades. An enormous amount of potable water is required for household, industrial and agricultural activities, which led the water authorities to look-out for suitable alternatives. Treated greywater reuse and recycling is an economically viable and attractive option for meeting a portion of future water demand. The feasibility of a continuous mode solar photocatalytic system in greywater treatment was explored in this study. The solar photocatalytic tests were employed with graphite-supported nitrogen-doped titanium dioxide (N-TiO₂). The effect of flow rate (20–70 mL/min) was investigated under pH-3, H₂O₂ dosage-1 g/L, catalyst dosage-5 g/L in a continuous reactor. These tests revealed that the maximum removal efficiency in terms of COD, TOC and NH₄-N was accomplished at 20 mL/min, while the lowest removal efficiencies were found at 70 mL/min. The removal efficiencies of COD, TOC, and NH₄-N were progressively reduced from a flow rate of 20 to 50 mL/min, followed by a sharp drop at a flow rate of 70 mL/min. The reactor operation at the lowest flowrate i.e. 20 mL/min showed the removal efficiencies of 71.8, 65.1 and 63.7% for COD, TOC and NH₄-N, respectively. The result showed that a solar photocatalytic system with GT-NTiO₂ could be effectively used for greywater treatment under continuous mode operation.

The objectives of these experiments were to investigate the effect of current and electrodes surface area on color removal efficiency and energy consumption. The result was showed that color removal efficiency was more than 95% for current apply 0.4–0.5 A, that pH increased with increasing time of electrolysis, then stabilize at close to 8–9. Amount of current density was indicate that increasing current was correspond to increase a removal efficiency that according to Faraday’s law. As for, the electrode surface area with constant current, the color removal efficacy is the trend to increase. During electrolysis, larger electrodes provide higher color removal efficiency than smaller electrodes. Also, the larger electrodes can also reduce the applied voltage of the system that cause of low operation cost. For effect of current per electrode area constant but difference current and electrode area, Color removal efficiency was difference where removal efficiency was depend on the current density. The conclusion was indicated that both of current and electrode area was effect to electrocoagulation process.

From 2009, the Mekong River’s water quantity and quality have been significantly reduced. The phenomenon happened as a result of climate change and human activities. Activities to block the flow or build dams to construct hydroelectricity or diversion in upstream countries are either the direct cause or the risk of further deterioration of the water quality and quantity of the Mekong River. The current status of the Mekong River’s water resources poses serious challenges for sustainable development of the Mekong River’s Basin. To cope with the problems, Agreement on the Cooperation for the Sustainable Development of the Mekong River Basin 1995 (Mekong Agreement) is the only multilateral treaty directly regulating the protection of water resources in the Mekong River. The principle of sustainable development, however, is not specified in a specific article, embodied in the Mekong Agreement through the contents of this treaty. Besides, the crucial obligations lacks an monitoring mechanism and has an unreasonable dispute solution.

In order to use the river water, a new renewable energy, as the cooling and heating sources for the air conditioning system, the temperature, quality and quantity of water in the downstream of Fujiang River is analyzed; it is believed that it is suitable to use the properly processed river water as the cooling and heating sources for the air conditioning system. The floor area ratio in the riverside is relatively high and the building coverage ratio is large, and its horizontal and vertical distances to Fujiang River are short; therefore, those favorable conditions contribute to the application of the river water source heat pump air conditioning system. With a residential community in downstream of Fujiang River as the research object, the system mode and water intake method for the water resource heat pump air conditioning system are analyzed; it is believed that it is advantageous to adopt the open system and direct water intake method; referring to the existing performance model of the heat pump unit, the operation of the water resource heat pump system is optimized with the aim of high energy efficiency; it is further believed that the energy efficiency ratios in the heating and cooling seasons reach 4.12 and 4.42 respectively. Compared with the conventional air conditioning system, the energy cost saving rate for adopting the river water source heat pump unit is 23.78%. The harmful gas emission reductions are as follows: CO₂: 3450.09t/a, SO₂:14.58t/a, NO₂:5.73t/a, smoke dust: 100.12t/a, with reduction amplitudes of 66%, 54%, 55% and 53% respectively. The application of river water source heat pump unit for water intake and discharge in the downstream of Fujiang River has little influence on water in Fujiang River. The research provides reference for the application of river water source heat pump air conditioning system in the downstream of Fujiang River.

The contamination of sulfate ions leading to corrosion is a severe problem in the aquatic environment, and adsorption is an effective method to remove this contaminant. In this study, magnetic silica-chitosan hybrids (MP@SiO₂/CPTMS/Chi) prepared by the sol-gel method have been used for adsorbing sulfate ions from an aqueous solution. The maximum adsorption capacity (Q_max) of the adsorbent for sulfates was 108.50 mg g⁻¹ at pH 3. The MP@SiO₂/CPTMS/Chi can be easily magnetically separated (completely separated less than 5 min) from the solution after the adsorption process. High adsorption capacity and easily magnetic separation make MP@SiO₂/CPTMS/Chi a prospective candidate adsorbent for removing sulfates from wastewater.

To understand the development history and variation of research focused on water and sediment in the Heilongjiang River Basin, statistical analysis was conducted based on the databases in Web of Science. Aspects including the number of publications, countries, institutes, subject categories, words in the title, and article adoptions were analyzed, which could provide a basis for future research directions. The results show that the development history can be divided into three stages: the early stage from 1943 to 2001, the rapid development stage from 2002 to 2013, and the current stage of 2014 to present, where the number of publications per year is relatively large. China and Russia pay the highest attention to this field because Heilongjiang is a boundary between the two countries. Correspondingly, most number of publications are from the Russian Academies of Science followed by the Chinese Academies of Science, which are followed by the universities and institutes in the northeast of China which account for the third largest number of publications to the tenth largest number. Furthermore, it was found that international cooperation is scarcer than domestic cooperation. As for the subjects, the number of publications under the subject of ecological environment ranks first; attentions paid to water and sediment movement and riverbed evolution are low. The results of title word frequency for all publications show that the word “water” ranks first which is much higher than “sediment;” “soil,” which is related to agriculture and forestry, ranks second. Currently, research on characteristic analysis is at the forefront, model development is next, and the theoretical studies are relatively scarce. Our research is of immense significance since the results of our study can identify research hotspots and trend changes, and hence, can provide references for research in the same field.

Floods and heavy rain events are on the rise, fostered by climate change. They cause damage in the same order of magnitude, but heavy rain can fall anywhere, irrespective of rivers or creeks and therefore affect everyone. The larger infrastructural measures taken by governmental authorities must be supplemented by private precautions taken by citizens themselves. The Floodlabel is a multi-stage concept that explains to homeowners their flood risk and provides instruction as to how to structurally secure their property against damage caused by floods, heavy rain, sewer backwater and groundwater. If these personal provision measures are implemented by sufficient numbers of citizens, this will strengthen the resilience of the community to these events. As this is a topic of international relevance, the Floodlabel developed in Germany and recommended by the climate protection portal of the German federal government is now being further developed for international use and is currently being adapted within two research projects for the special needs and conditions on the ground in Ghana and Iran.

The research object is Bulgaria as a tourist destination. Research subject is sustainable environmental planning for tourism purposes. The competitive usage of the territory imposes the search of possibilities for carrying out a few different and sometimes mutually excluding activities. Careful environmental planning is needed, and in order for it to be sustainable, it must not violate the right of future generations to use this territory as well. The tourism is a spatial phenomenon and is a very important sector of the Bulgarian economy. Its sustainable development is a priority for the government of the country. The Ministry of tourism is developing a targeted policy towards establishing the field and is trying to introduce some relieves so it can help the tourist companies in overcoming the current crisis. Significant progress in the development of tourism provides the division of the territory into nine tourist regions, which aim to stabilize the tourist supply in Bulgaria. The publication aims to analyse the development of regulations in the field of spatial planning, to show the progress made in terms of tourism environmental planning and on this basis to outline trends in the future development of the destination Bulgaria.

We propose an analytical framework for sustainable management of sediment-algae dynamics in dam-downstream river environment. The problem considered in this short paper is an optimization of the dynamics by sediment replenishment schemes having multiple objectives: cost-efficient sediment supply and prevention of the bloom of nuisance benthic algae. We apply an Ergodic long-run stochastic control model to this problem, and show that it can be solved analytically being different from many other multi-objective optimization models. The sediment storage and algae population dynamics follow ordinary differential equations perturbed randomly by the sediment replenishment. We show that the most cost-efficient policy, namely the optimal sediment replenishment policy, is of a threshold type that is implementable in the real world. We analytically lead to a practical sustainability criterion that is based only on the biological and physical parameters, which can be specified prior to implementing a replenishment scheme. Our model is simple, but can give useful and practical insights into sustainable river environmental management.

Many complex challenges have marked Europe's transition to Economy 4.0 and Society 5.0. One of them, considered at all possible levels of government, is implementing EU environmental policy. The consensus in principle in this area does not always lead to the achievement of strategic environmental goals. The reasons are rooted in the objective comprehensiveness of the ecological transition. We argue that it is evolving far beyond the complicated governance structure of the Union. An additional condition is an undeniable and very close connection between the national and integrated economy with global and regional trends. The transformation to Bulgaria's environmentally friendly economy was preceded by a socio-economic transition, culminating in the country's integration into the EU and a convergent transition, which we will say is only in its infancy. Therefore, we are faced with assessing Bulgaria's potential to mobilize its available resources (managerial, spiritual, cultural, material, financial, and integration) to develop the most effective available “environmental” tools. Environmental policy should not be implemented only with the tools for management and administrative control but should also be added to the available scientific, financial, and technical means.

Oil sorbents based on carbon-containing waste of coal, woodworking enterprises and active sludge of biological treatment facilities were developed at the Department of Chemical Technology of Solid Fuel T. F. Gorbachev Kuzbass State Technical University. These sorbents performed well for water cleaning from oil, but they have low strength. Hardening methods of the developed granules are proposed and their influence on the characteristics of oil sorbents, such as moisture, ash content, density, volatile yield substances, compressive strength, as well as moisture and oil capacity were studied in this article.

The floc formation, breakage and regrowth processes were investigated by numerical simulation to explore the effect of hydraulic retention time on ultrafiltration membrane (UF) fouling. Using a numerical method, the floc average size, fractal dimension and porosity under various coagulation conditions were investigated. The standardized flux and invertibility of membrane fouling were also investigated. Results illustrated that flocs formation under shorter flocculation time (10 min) had a small value of fractal dimension, which readily generated a larger pores and shaggy cake layer on the surface of membrane. An initial simplified breakage model based on DLA model was proposed, which demonstrated that the broken flocs afforded more opportunities for diffused particles to access deeper-lying flocs uniformly packed around the aggregated core. Flocs became increasingly compact with increased time of stirring after breakage. Therefore, shortening of stirring time, whether during flocculation or recovery process, could enhance the permeability of membrane.

In this study, we use the electrodialysis technique (ED) to recycle chemical polishing agents, including the removal efficiency of aluminum ions and water quality variation. Finally, the electricity consumption of the ED technique for separating aluminum ions was estimated. The ED system was composed of a cation exchange membrane, anion exchange membrane, and graphite electrode. With a current of 1.0 A and an average voltage of 70 V, the treatment time was 60 min. The results showed that variation of pH and conductivity in the wastewater has a stable status. The aluminum ion concentration was rapidly decreased from about 11,056 to 2,512 mg/L in the wastewater chamber within 30 min, and the removal efficiency reached 78%. The variation of concentration indicated that the high concentration of aluminum ion is rapidly adsorbed on the cation exchange membrane under the ion permeation in the early stage of operation, resulting in a significant decrease in the aluminum ion concentration. After the adsorption was saturated, the aluminum ion became movable from the cation exchange membrane to the cathode under electromigration. With the operating time, the concentration of aluminum ions gradually increased at the recovery chamber. The electricity consumption shows that the ED can effectively separate aluminum ions in the wastewater and recycle chemical polishing agents.

The publication explores the possibilities for integrating the global goals for sustainable development in Bulgaria’s strategic regional planning process. The authors consider the concept of achieving sustainable development in its strategic aspect. The scholars’ thesis is that strategic planning plays a crucial role in the regions’ future and is a reliable tool in their transition to sustainable development. The integration of sustainable development goals begins at the planning stage at national, regional, and local levels. In the study, the authors examine the United Nations Agenda 2030—Sustainable Development Goals and the new European consensus on the development ‘Our World, Our Dignity, Our Future.’ The author’s team also studies the legal framework and institutionalization of sustainable development in Bulgaria at the beginning of the XXI century. Current strategic documents for regional development are assessed for their compliance with the Global Sustainable Development Goals. To this end, the research team investigates the current strategic framework for regional development and conducts it, focusing on the environmental dimension of sustainability. The effective use of sustainable development opportunities is a proper perspective for regional policy in achieving maximum dynamics for socio-economic development in Bulgaria and its participation in building a competitive European economy based on knowledge and innovation.

Construction safety risk assessment coupled with multiple factors is essential for the risk control in complex and changing navigable waters. Aiming at the characteristics of uncertainty, dynamics and fuzziness for engineering construction in navigable waters and the problems including incomplete risk index system, the risk-classification-quantification-standard unsuitable for real-time dynamic risk evaluation, and the empirical judgment for the current construction risk assessment, a general three-level safety risk index system was established based on the mutual influence and subordination of risk factors including the effect of human-related, equipment and environment factors. Taking the dredging project of a large trailing suction dredger as an example, the three-level quantitative standard of risk classification was established from the integration of objective evaluation mechanisms and subjective evaluation mechanisms, and the fuzzy comprehensive evaluation method was used to set up a comprehensive multifactor construction safety risk evaluation model. Finally the model was applied to the eighth phase of the Hengsha Dongtan silt promotion ring project successfully. The model of construction safety risk assessment coupled with multiple factors will provide effective reference and guidance for real-time dynamic construction risk assessment and control in navigable waters.

To know the situation of plastic particle concentration and distribution in Taiwan western costal, this study selects the sea area in Hsinchu County to conduct an analysis. Therefore, samples were taken in the beaches, beach junction sea area, estuaries and lower reaches of the river from Hsinchu County. And the thermal contact meth (NIEA M909.00C) for the detection of microplastics in water announced by Environmental Analysis Laboratory, Environmental Protection Administration, Executive Yuan is selected to investigate the concentration of plastic particles. At the same time, type of plastic particles under the microscope was recorded to further analyze the possible causes and sources of those plastic particles. The analysis results show that in terms of the distribution of plastic particles, the concentration of plastic particles on the beach is 25.3–53.3 items/kg; the concentration of plastic particles in the sea area is 1.6–8.0 items/L; the concentration of plastic particles in the estuaries and lower reaches of the river is 2.3–3.6 items/L. At each sampling location, the plastic particles are mainly long strips, and a few are round and flakes. The elongated plastic particles are mainly derived from discarded fishing nets or waste clothing; the main source of round plastic particles is cleaning agents; and the flake plastic particles are generated by plastic degradation. On the whole, the smallest appearance of plastic particles is round or spherical, which means that the occurrence rate of microbeads in the water bodies of Hsinchu County is low. It shows that the government has achieved remarkable results after banning the use of microbeads.