The reason for choosing the topic
A river basin is a geographic area where all water sources, including surface water, groundwater, and rainfall, naturally flow into rivers or streams, defined by specific dividing lines This area plays a crucial role in influencing surface water quality and acts as a gateway for various substances from the basin and surrounding regions to enter the river Consequently, the watershed can significantly impact the ecosystem, particularly when affected by human activities such as industrial and residential waste disposal.
A particular, Bien Hoa 1 Industrial Zone is located in the Dong Nai river basin This is one of the industrial parks formed very early in 1963, with a total area of about
The industrial zone spans 335 hectares and is situated alongside the Cai River, a tributary of the Dong Nai River Inadequate pollution control in the Bien Hoa 1 Industrial Zone could severely impact the environmental quality and the ecosystem of the Dong Nai river basin.
Bien Hoa I Industrial Park, located near the An Binh Residential Area, plays a significant role in the local socio-economic development However, the proximity of residential zones to industrial activities poses a risk of declining environmental quality Additionally, the aging production technologies within the industrial park raise concerns about potential hazards Despite multiple infrastructure upgrades over the years, the area remains a source of alarm due to environmental water pollution linked to industrial operations.
Some experts said that to solve pollution in the Dong Nai river basin, especially in the Cai river basin, the pollutants must be monitored more tightly Therefore, it is
Timely research is essential to prevent the direct discharge of untreated wastewater into the environment, as seen in some regions It is crucial to implement measures to monitor and address the pollution of water sources caused by industrial zones.
The study on "Examination of the Effects of Wastewater Treatment Methods in Bien Hoa I Industrial Zone" is essential for enhancing pollution control and managing environmental quality in the Dong Nai River basin, driven by the industrial activities in Bien Hoa I industrial park.
Objectives of the study
Assessment of waste water status in Bien Hoa I Industrial Zone through monitoring indicators
Forecast trend of pollutant load in waste water in Bien Hoa Industrial Zone I
Proposing solutions to control and minimize pollution of wastewater treatment in Bien Hoa Industrial Zone I
Object and scope of the study
Object
Wastewater norms of Bien Hoa I Industrial Zone
Load of industrial waste discharge
Scope
Comparison with standard and status
Statistics, calculate the load parameters
The meaning of the topic
Scientific meaning
The study's findings enhance the understanding of the river basin's ecological environment and contribute valuable insights to existing literature both domestically and internationally By providing data citations and references, this research aids in preserving essential statistics for future works on river ecosystem ecology and supports discussions on predicting contamination load trends in industrial parks.
Practical meaning
Research plays a crucial role in enhancing the management of Bien Hoa I Industrial Park and similar older or relocated industrial parks It provides a scientific foundation and practical insights for effective planning, especially in scenarios where Bien Hoa Industrial Zone I needs to transition to new functions.
OVERVIEW OF RESEARCH
Water pollution
Water pollution is defined variably across Indian legislation, with some acts referring to it as a "nuisance" or "negligence," while others describe it as "fouling" or "poisoning" of water Certain statutes highlight the impact of pollution on the suitability of water for human and animal consumption Additionally, interference with water flow, leading to contamination, is another aspect of water pollution Prior to the Water (Prevention and Control of Pollution) Act of 1974, most laws focused on the causes of pollution rather than its definition In essence, water pollution involves the introduction of harmful substances or changes to water's physical and chemical properties, making it unsuitable for legitimate use Polluted water contains foreign substances that alter its essential characteristics, rendering it unfit for consumption.
The Water (Prevention and Control of Pollution) Act, 1974 defines water pollution as the contamination or alteration of water's physical, chemical, or biological properties This includes the discharge of sewage, trade effluents, or any harmful substances into water bodies, which can create nuisances or pose risks to public health, safety, and legitimate uses, as well as the life and health of animals, plants, and aquatic organisms.
The total amount of water on the earth is about 1.35 billion cubic kilometres (3.5x1020 gallons) Over 97 percent of this quantity is in the oceans as salt water
The Earth's fresh water is limited to 37 million cubic kilometers, with 80% found in polar ice caps and glaciers Daily, we utilize approximately 50 cubic kilometers from rivers, streams, and lakes, alongside 70 cubic kilometers from underground reservoirs, a supply that has remained stable for thousands of years However, the demand for water has surged dramatically over the last century In India, this rising demand has led to a significant decrease in the average annual water availability per capita, dropping from 5,236 cubic meters in 1951 to a much lower figure today.
In 1991, India's water availability was 2227 cubic meters per capita, but projections indicate a decrease to just 1555 cubic meters by 2013 With the population currently exceeding one billion and expected to rise between 1.5 billion and 1.8 billion, the country faces significant water scarcity challenges.
By the year 2050, India will need an annual water supply of 2,788 billion cubic meters to remain above the water stress threshold, while 1,650 billion cubic meters is essential to prevent the country from becoming water scarce.
There are hundreds, perhaps thousands of pollutants whose effects are of actual and potential concern Their numbers increase annually as new compounds and formulations are synthesized [18]
Several attempts have been made to group water pollutants into classes or categories Pollutants have been classified according to their mode of occurrence into physical, chemical and biological pollutants [22]
Table 1.1 Classification of water pollutants [22]
Turbidity Waste neat from industry
Silt, sand, metal pieces, rubber, wood chpis, paper, foam, scum, carcasses, sewage.
Inorganic Nitrites, phosphates, chlorides, fluorides, salts etc
Organic Detergents, tar, plastic, pesticides.
Pathogenic Bacteria, virus, nematodes, worms, protozoans
Nuisance organisms Slime, mollusc, algae, Ascellus, nematodes.
Rapid industrialization in Vietnam, initiated after independence, aimed to boost the economy but inadvertently led to significant water pollution While industrialization was viewed as a key driver of progress, it also introduced severe environmental challenges that threaten human civilization Concurrently, population dynamics shifted, resulting in a sharp increase in urban density and the rapid expansion of major cities, further exacerbating the issue of pollution.
15 rise to increased domestic pollution and also increased agricultural pollution as food production had to match the raising needs of the population
The sources of water pollution are innumerable Major sources can be found in practically every variety of industrial, municipal and agricultural operations
Industrial waste, also known as trade effluent, refers to any liquid or solid substance discharged from industrial premises, excluding domestic sewage Many industries situated along riverbanks often release their effluents into nearby rivers, leading to significant water pollution These industrial effluents typically contain hazardous substances such as mercury, lead, cadmium, and copper, which pose serious threats to aquatic life.
Justice V.R Krishna Iyer once remarked that, ―the unconscionable industrialisation, the unpardonable deforestation and the inhuman extermination of living species betray an exploitative brutality and anti-social appetite for profit and pleasure which is incompatible with humanism and conservationism Today a bath in Yamuna and Ganga is a sin against bodily health, not a salvation for the soul, so polluted and noxious are these holy waters now [29]
As human population growth accelerates, the once seemingly endless water supplies have become limited, leading to a critical reduction in per capita water availability This shift makes it imperative to prevent the loss and contamination of existing water resources while ensuring sustainable usage The future of human activity is now intricately linked to our ability to manage and protect our water supplies effectively.
16 poses a serious health hazard to communities living nearby, and which depend on that source for most of their activities
Water pollution can cause both immediate and long-term health effects Acute effects occur within hours or days of the time that a person consumes a contaminant
Exposure to extraordinarily high levels of contaminants can lead to acute health effects, particularly from microbes like bacteria and viruses found in drinking water, which pose the greatest risk of reaching dangerous levels.
Surface water contamination poses significant risks not only to human health but also to aquatic ecosystems These ecosystems are crucial for providing essential services to human societies, such as food through fisheries, recreational opportunities, and irrigation water for agriculture.
Water pollution is a critical issue with severe implications for human survival, as access to clean water is essential The growth in population, driven by industrialization and urbanization, has intensified pressure on natural resources Additionally, the rising demand for food has led to increased use of fertilizers and pesticides, contributing significantly to water pollution It is imperative that we take action to address this growing threat before it becomes irreversible.
Overview of Status of industrial environment managementin the world and
"Sustainable Development" was the goal of all mankind in the 21st century as the Global Environment Conference held in Rio de Janeiro (Brazil) in June 1992 with
The participation of over 170 heads of state highlights the global commitment to achieving critical objectives To effectively address the harmful impacts of socio-economic activities, countries must implement integrated measures that encompass management, technology, economy, education and training, as well as environmental awareness.
Environmental pollution in manufacturing facilities is effectively tackled in many developed countries, including the USA, Japan, Canada, the UK, Singapore, Taiwan, and Korea, as well as in some developing nations like Thailand, India, and Malaysia Various technological measures have been implemented to significantly reduce pollution levels in these regions.
- Waste water treatment technology: mechanical, chemical, chemical, biochemical and biological methods
- Waste gas treatment technology: dry methods (settling chamber, cyclone, sleeve filter, electrostatic filter, etc.), wet methods (absorption, oxidation reduction )
- Solid waste treatment technology: burying, cleaning, chemical, biological, reuse
In addition to technological measures, many integrated solutions are also applied to reduce pollution at production facilities such as:
- Use educational measures, raise environmental awareness
Use administrative measures (eg closure) or relocation of polluting facilities
Under the "Industrial Pollution Reduction Program" implemented by the New Jersey Environmental Protection Agency in 2002, steps to reduce environmental pollution in industrial facilities include:
- Identify processes and sources of pollution
- Find and analyze options for environmental pollution prevention
- Develop a plan to reduce environmental pollution
The World Health Organization (WHO) Water Pollution Control (1997) report shows that the principles that need to be taken to reduce water pollution from industrial activities include:
- Prevent waste from the production process
- Dispose of waste before discharging into the receiving water or discharging into the wastewater treatment system of the area to minimize the costs incurred
Between 1994 and 2002, the World Bank implemented an industrial pollution mitigation project in India to support the government's pollution prevention policies and promote cost-effectiveness This initiative targeted the most polluting industries and comprised three main components: policy institutions, investment capital, and technical assistance The institutional and policy components aimed to enhance water pollution control, while the investment component focused on aiding small businesses in minimizing waste and adopting cleaner production methods Additionally, the technical support components included establishing a clean technology organization network, expanding services for waste minimization and disposal for small-scale industries, conducting pre-investment research, and providing financing for training and consulting services related to environmental reporting.
In Vietnam there have been many studies on environmental protection in the Industrial Park, some case studies:
In 1999, Lam Minh Triet and colleagues created a draft regulation focused on environmental protection within industrial parks in Vietnam, assessing the development status and environmental changes in these areas Their research informed state management agencies, leading to the issuance of circulars aimed at enhancing environmental protection measures for both industrial zones and factories operating within them.
The topic of "Research on building a unified environmental management system in the Industrial Park" by the Center for Environmental Technology and Management
(2004) has proposed models of environmental management systems for The
20 industrial parks in Vietnam include the Eco-Industrial Zone and the Industrial Park
The project introduces a two-tier environmental management system for the Industrial Park, focusing on waste treatment at both the factory and industrial zone levels It emphasizes the importance of effective environmental management, utilizing tools such as analysis, action, and information to support sustainable practices within the Industrial Park.
Le Thi Hong Tran et al (2010) conducted a study on ecological and health risk assessments in Ho Chi Minh City's industrial parks, specifically focusing on Vinh Loc and Tan Thoi Hiep Industrial Parks The research utilized quantitative methods, including risk quotient (RQ) and hazard quotient (HQ), to evaluate ecological risks from industrial wastewater and health hazards from air pollution affecting workers Additionally, a risk matrix was employed to assess the ecological impact of industrial wastewater on surface water The findings revealed varying levels of risk—high, medium, and low—associated with industrial wastewater, highlighting the differences between industrial zones with and without centralized wastewater treatment systems.
The 2009 National Environment Report highlights significant challenges faced by industrial zones (IZs) in Vietnam, particularly concerning environmental pollution from waste, sewage, and industrial emissions If these issues are not effectively addressed, they could lead to environmental disasters and climate change, jeopardizing public health and undermining recent advancements in industry and economic development Efforts have been initiated in the Nai River basin and Nhue-Day River to reduce pollution and promote sustainable industrial growth Enhancing institutional and technical capacities, along with fostering community involvement in monitoring and enforcing environmental protection laws, is crucial, especially in the context of the Dong Nai and Nhue-Day river environments.
To mitigate environmental pollution in industrial parks, a comprehensive approach is essential, incorporating various strategies such as the development of eco-industrial park models, implementation of waste treatment technologies for wastewater and emissions, conducting waste audits, and promoting cleaner production practices Additionally, the establishment of regulations and circulars focused on environmental protection, along with the application of economic tools for waste management, plays a crucial role in fostering sustainable industrial practices.
Overview of the geographical area around Bien Hoa Industrial Zone
1.3.1 Natural conditions in Dong Nai province
Figure 1.1 Map of Dong Nai province [8]
Dong Nai, located in the Southeast region, encompasses 11 administrative units and covers a total area of 5,897.75 km² The province features a diverse topography, including flat plains, rolling hills, and low mountains.
The Dong Nai river system is extensive, featuring a primary network that comprises the La Nga River, Be River, Sai Gon River, and Vam Co River.
Figure 1.2 The network of major rivers in the Dong Nai river basin [8]
Dong Nai River is influenced by the semi-diurnal regime up to two times, so salinity intrusion, especially the Thi Vai River, has a salinity of up to 28.4 ‰
1.3.2 Socio-economic impact on the environment
From 2011 to 2015, Dong Nai province experienced an average annual gross domestic product (GRDP) growth of 12%, driven by a 12.2% increase in industry and construction, a 14.4% rise in services, and a 3.5% growth in agriculture, forestry, and fishery This shift marks a transition from a primarily agriculture-based economy to a diverse, multi-sector economy, with a strong focus on industry, construction, and services.
The rapid and intense development of the industry lead to the problem of environmental pollution, especially the problem of untreated industrial wastewater
24 discharged directly into the environmentin the Dong Nai river area It is one of the major challenges for the sustainable development of the province
By the end of 2015, Dong Nai Province's population reached 2,905,850, marking an increase of 265,610 since 2011 The urban population accounted for 1,009,260 people (34.73%), while the rural population comprised 1,896,590 individuals (65.27%) This gradual rise in urban population from 33.68% in 2011 to 34.73% in 2015 is attributed to both natural growth and migration However, this population surge has contributed to various environmental challenges.
Overexploitation depletes natural resources, severely affecting the ecosystem
Industrial activities in the province contribute significantly to environmental pollution, generating approximately 190,000 m³ of domestic wastewater and 2,605 tons of solid waste daily This pollution adversely affects soil, water, and air quality, with local air pollution detected around industrial zones.
The rapid growth of urban populations and the emergence of megacities are putting immense pressure on the urban environment, leading to significant degradation As cities expand, the demand for clean water, housing, and green spaces outpaces supply, resulting in increased air and water pollution and heightened challenges in solid waste management.
In 2015, the industrial production value in the province reached an estimated VND 586,105 billion, reflecting a 12.5% increase from 2014 and 1.6 times higher than in 2011, which was VND 365.184 billion The average annual growth rate from 2011 to 2015 was 12%.
Figure 1.3 Comparative chart of industrial production value [8]
On the comparative price of 1994, industrial production value in the province in
In 2015, the estimated value reached 206,500 billion VND, reflecting a 13.5% increase from 2014 and doubling the figure from 2010 The average growth rate between 2011 and 2015 was 15%, although it fell short of the targeted 16% annual growth rate, it still surpassed the national average.
Between 2010 and 2015, the state sector's share decreased from 8% to 5%, primarily due to the equitisation of its head office and a rise in foreign investment, which increased from 80.4% to 84.4% Meanwhile, the non-state sector remained stable at approximately 11%.
The industrial sector's value is predominantly found in processing and manufacturing, accounting for over 98% of the total Key industries include industrial food processing of agricultural products at 30%, followed by textiles, garments, and footwear at 27% Mechanical engineering and metallurgy contribute 17%, while the chemical and rubber industries represent 15% Lastly, the electricity and electronics sector makes up 10% of the industry's value.
Figure 1.4 Distribution of industry groups in the industry structure [8]
From 2011 to 2015, industries such as agriculture, food processing, textiles, garments, footwear, mechanics, metallurgy, chemicals, and rubber experienced robust growth, averaging 12-13% annually In contrast, the electricity and electronics sector saw a modest growth rate of around 5% per year, primarily attributed to a decline in product output from Fuzitsu, driven by increased competition and reduced orders.
During this period, the province's key industrial products include ready-made garments, various textile fabrics, a wide range of footwear, iron and steel, animal feed, poultry, candy, sweeteners, fertilizers, plant protection drugs, and a variety of electric and electronic products such as TVs, air conditioners, refrigerators, washing machines, and computers, along with spare parts for mechanical equipment.
In 2010, there were 12,200 establishments, projected to rise to 13,700 by 2015, reflecting an annual growth rate of 2.4% Correspondingly, the number of employees is expected to grow from 463,600 in 2010 to 675,900 in 2015, averaging a significant increase of 7% per year.
In the period of 2011-2015, Dong Nai province has attracted about 300 foreign invested projects and increased capital of 339 projects with the total capital of USD
Mechanical engineering, metallurgyChemical and rubberElectricity - electronicsOther
In total, there has been an influx of 6,360.08 million USD, comprising 2,776.89 million USD in newly registered capital and an additional 3,583.19 million USD The industrial sector leads with 228 projects, representing 77.3% of all attracted projects, which include 7 high-tech industrial initiatives and 85 supporting industrial projects.
Dong Nai province is home to 31 industrial zones (IZs), with 29 currently operational and 73% of the land occupied These zones have successfully attracted 1,342 investment projects from both domestic and foreign enterprises, including 973 foreign direct investment (FDI) projects from 40 countries, totaling USD 17.7 billion Additionally, there are 369 domestic projects with a combined capital of VND 43 trillion In recent years, investment in Dong Nai's industrial zones has exceeded $1 billion.
2014, attracting USD 1.5 billion and over VND 4 trillion
CONTENT AND METHODOLOGY
Content
Assessment of waste water situation in Bien Hoa Industrial Zone 1
Forecast of pollutant discharge load trends to 2020, 2025
To propose comprehensive solutions to control and minimize environmental pollution in Dong Nai river basin due to the activities of Bien Hoa 1 Industrial Zone
Methodology
Industrial activities and their stakeholders significantly impact the ecological environment, forming a dynamic relationship influenced by various internal and external factors This ongoing interaction necessitates a careful balance to ensure sustainability within the broader ecosystem.
Polluted water from industrial parks disperses contaminants throughout a river basin, affecting various water bodies from small streams to larger rivers and ultimately reaching lakes or seas This contamination persists until aquatic ecosystems can effectively self-purify, highlighting the importance of maintaining healthy waterways for environmental balance.
2.2.2 Method of inheritance, collection of information, data
Based on a selective inheritance of previous research conducted in the study area and the necessary information for research
Overview of data collection on current status and planning orientation of industrial zones / clusters in the study area
- Data on natural, socio-economic and population data
- Reports, design documents of industrial parks in the scope of research subject
- Documents for the process of proposing mitigation measures
In addition, the research also synthesizes research documents or application of environmental assessment indicators and environmental classification
2.2.3 Method of investigation, field survey
This study focuses on surveying the industrial zone and its surrounding environment, particularly assessing the water drainage systems of enterprises within the zone It examines the current status of a dedicated wastewater treatment system for certain facilities and evaluates the centralized wastewater treatment system utilized by the Bien Hoa 1 Industrial Zone, which is integrated with the common system of the Bien Hoa 2 Industrial Zone.
2.2.4 Method of data processing, statistics, evaluation
With the current status of the IZs, production facilities and wastewater treatment status, a list of selected facilities for field survey is prepared
Based on the results of the analysis, we compared our results with current QCVN for industrial wastewater parameters and classify the level of environmental pollution to wastewater
We studied related documents and propose technical solutions to contribute to the reduction and control of water pollution in industrial zones
2.2.5 Sample collection and analysis of wastewater
The collected data on wastewater quality inherited from the project on pollution control of industrial zones in Dong Nai river basin, Nhue-Day river (ViPMP)
The members directly involved in the implementation of the Environmental Monitoring Program include staff from the Center for Analysis and Environment
Duong Hai Au - Director of Center for Analysis and Environment
Table 2.1 List of other participants [21]
No Work content Participants Position
Duong Hai Au Nguyen Thi Thuy Van Nguyen Thị Hồng Diem Nguyen Thuy Diem Nguyen Mạnh Trung
Le Văn Quy Nguyen Van Tan Nam
2 Analysis of samples in the laboratory
Nguyen Thi Thuy Van Nguyen Thị Hồng Diem Nguyen Thuy Diem Nguyen Mạnh Trung
Le Văn Quy Nguyen Van Tan Nam Tran Thi My Duyen
Deputy Head of Analysis Division
- Time for completion of monitoring results: 30 September 2016 shall be conducted according to the following sampling methods:
VNS 6663-1:2011: Water quality Technical guidance on sampling
VNS TCVN 6663:2008: Water quality Guide to preservation and handling
VNS TCVN 5999:1995: Water quality Guide to waste water sampling
VNS TCVN 8880-2011: Water quality Sampling for microbiological analysis
Sampling directly from the mouth, contained in specialized bottles
Table 2.2 Parameters and methods of analysis of waste water samples [21]
No Parameters Unit Methods of Analysis
12 CN - mg/l HD 54- PT-CN
No Parameters Unit Methods of Analysis
SMEWW 3500.Cr.B:2012 Table 2.3 Location of wastewater sampling in Bien Hoa Industrial Zone 1 [21]
Name company Sampling locations Sample symbol
Dry Cell and Storage Battery Joint
Stock Company (Pinaco) input 16091504-NT1
Dry Cell and Storage Battery Joint
Stock Company (Pinaco) output 16091504-NT2
Bien Hoa Chemical Company Limited
Bien Hoa Chemical Company Limited
Southern Steel Sheet Co Ltd (SSSC) input 16091504-NT5 Southern Steel Sheet Co Ltd (SSSC) output 16091504-NT6
Ajinomoto VietNam Co input 16091504-NT7
Ajinomoto VietNam Co output 16091504-NT8
Net Washing Powder (NETCO) after filter, input wts 16091504-NT9 Vinacafe Bien Hoa Joint Stock
Name company Sampling locations Sample symbol
Vinacafe Bien Hoa Joint Stock
DIELAC Dairy Factory- VINamilk input 16091504-NT12
DIELAC Dairy Factory- VINamilk output 16091504-NT13
Tam Hiep Rubber Technical Factory collection tank 16091504-NT14 Bien Hoa Sugar Joint Stock Company input 16091504-NT15
Bien Hoa Sugar Joint Stock Company output 16091504-NT16
South Basic Chemicals Joint Stock
Dong Nai Paint Corporation collection tank 16091504-NT18
Dong Nai Tile Corporation collection tank 16091504-NT19
Corporation (350.000 Ton/year) collection tank 16091504-NT20
Bien Hoa Packaging Company – paper workshop input 16091504-NT21
Bien Hoa Packaging Company – paper workshop output 16091504-NT22
Centralized Wastewater Treatment input 16091504-NT25
Name company Sampling locations Sample symbol
Plant In Bien Hoa Industrial Zone II
Plant In Bien Hoa Industrial Zone II output 16091504-NT26
2.2.6 Method of calculating maximum pollutant load of pollutant in industrial effluents (Circular No 02/2009 / TT-BTNMT dated March 19, 2009 of the Ministry of Natural Resources and Environment)
2.2.6.1 Data requirements a Data on receiving water
Data on receiving water sources include flow data and pollutant concentrations assessed in water sources a.1 Data load
- Use flow data series observed in the river section being evaluated
- Where there are no flow data for the river sections being assessed, data from similar rivers may be used
- Graph the flow over time and select the smallest instantaneous flow to calculate the receiving capacity of the water source (as shown below)
Figue 2.1 Graph of flow over time and the smallest instantaneous flow [17]
For accurate assessment of water quality, it is essential to utilize actual observation data from the specific river section being evaluated, alongside river flow data that is relevant to the calculations or applicable during periods of minimum flow.
The sampling, preservation and analysis of water samples shall comply with the current regulations and standards and apply the following standards:
+ Standard TCVN 5992-1995: Technical guidance on sampling;
+ Standard TCVN 5996-1995: Guidelines for sampling in rivers and streams;
+ Standard TCVN 5999-1995: Guideline for wastewater sampling;
+ Standard TCVN 5993-1995: Guidance on preservation and processing of samples;
+ Standards TCVN on sample analysis in the laboratory,
To accurately assess the concentration of pollutants in receiving water, it is essential to collect a minimum of three samples from distinct locations along the same cross-section of the water body These samples should be taken at the midpoint, one-quarter width from the left bank, and one-quarter width from the right bank, all at a depth of 0.5 meters from the surface Additionally, data on wastewater sources must include the maximum discharge values and the highest pollutant concentrations present It is crucial to evaluate pollutants based on all substances outlined in water quality standards, as well as any additional pollutants found in wastewater that may not be listed in Vietnam's standards.
Surface water quality standards TCVN 5942-1995 (kind A, kind B);
Water quality standards for irrigation TCVN 6773-2000;
Freshwater quality standards outlined in TCVN 6774-2000 are essential for safeguarding aquatic life It is crucial to measure and monitor current wastewater discharge sources, while future waste sources should be evaluated based on scientific data.
The maximum load of pollutants that a water bodycan absorb for a specific pollutant is calculated using the formula:
L tđ (kg/day) maximum pollutant load of the water source for the pollutant in question;
Q s (m 3 /s) minimum flow velocity in the river section needs to be assessed before receiving wastewater, is determined according to instructions in ” a ” section 2.2.6.1 ;
Q t (m 3 /s) maximum discharge of wastewater, determined according to the instructions in ” b ” section 2.2.6.1 ;
The concentration limit of pollutants in water, measured in mg/l, is defined by water quality regulations and standards to ensure the water's intended use, as outlined in section "b."
* Calculate the pollutant load available in the receiving water
The amount of pollutant load available in the receiving water source for a particular pollutant is calculated by the formula:
L n (kg/day) pollutant load is available in the receiving water;
Q s (m 3 /s) minimum flow velocity in the river section needs to be assessed before receiving wastewater
C s (mg/l) maximum concentration of pollutants in water before receiving wastewater;
86,4 is a dimension unit conversion factor from (m 3 /s)*(mg/l) to (kg/day)
* Calculate pollutant discharge load of pollutant into water source
The pollutant load of a specific pollutant from the source of discharge into the receiving water source is calculated according to the following formula:
With: The pollutant load of a specific pollutant from the source of discharge into the receiving water source is calculated according to the following formula:
L t (kg/day) is the amount of pollutant in the waste stream
Q t (m 3 /s) is the largest sewage flow, determined according to the instructions at the point “b” section 2.2.6.1 ;
C t (mg/l) is the maximum concentration value of the pollutant in the effluent, determined according to the instructions at point “ b ” section 2.2.6.1
* Calculation of wastewater receiving capacity
The ability to receive pollutant discharge load of a water source for a particular pollutant from a single discharge point is calculated by the formula:
F s is the coefficient of safety, the value of this coefficient is determined as follows:
The Fs Safety Factor is essential in assessing pollutant acceptability because many factors affecting wastewater reception capacity, particularly concerning pesticide acceptance, are uncertain and difficult to quantify Additionally, insufficient information regarding wastewater discharge and downstream water usage complicates this evaluation This approach ensures that the capacity of a water source to receive wastewater is not solely reliant on a single source but is also capable of accommodating contributions from multiple downstream sources.
The safety factor (Fs) for pollutants typically falls between 0.3 and 0.7, indicating variability based on specific contaminants A lower Fs suggests that a minimal amount of wastewater's pollutant capacity is being introduced into water sources, reflecting significant uncertainties and elevated risks.
- It is important to clarify the arguments when determining the value of safety factor in the process of assessing the capacity of receiving wastewater from water sources
When the value of Ltn exceeds 0, the water source continues to be vulnerable to pollutants In contrast, a value of Lt that is less than or equal to 0 indicates that the water source is no longer susceptible to contamination.