Reducing Industrial Pollution: Protecting Our Freshwater Sources

Industrial pollution of freshwater is a pressing issue, with industries being the largest contributors to water pollution. The contamination of water sources by industrial waste, such as hazardous chemicals and metals, poses a significant threat to the environment, humans, animals, and flora. As industries play a crucial role in a country's economic growth, it is essential to explore ways to reduce their impact on freshwater sources. This includes minimizing water usage, reusing and recycling water, harvesting rainwater, treating wastewater, regulating groundwater usage, and adopting advanced water treatment technologies.

Minimise water use by reusing and recycling

Water is a precious resource, and reducing water use in industrial processes is essential for preserving freshwater sources. The principle of "reduce, reuse, recycle" is an important framework for sustainable water use. Here are some ways to minimise water use through reuse and recycling in industrial processes:

Reduce Water Use

The first step is to reduce the amount of water used in industrial processes. This can be achieved by implementing water-saving measures, such as:

• Using water-efficient technologies and processes: Industries can invest in water-efficient equipment and optimise their processes to minimise water usage.
• Promoting a culture of water conservation: Educating employees about the importance of water conservation and encouraging them to report any water leaks or wastage can help reduce water usage.
• Regularly maintaining equipment: Regular maintenance can help identify and fix leaks, preventing water loss.

Reuse Water

Reuse is the second "R" in the framework and plays a crucial role in minimising water use. Here are some ways to incorporate reuse into industrial processes:

• Recycling wastewater: Treated wastewater can be reused for various non-potable purposes, such as irrigation, industrial cooling, or toilet flushing.
• Planned water reuse systems: Communities can design water systems with the goal of reusing recycled water. This involves optimising water use within the community before reintroducing it to the environment.
• Capturing and reusing rainwater: Rainwater harvesting can be employed to collect and store rainwater for various industrial purposes, reducing the need for freshwater sources.

Recycle Water

The final "R," recycle, involves treating and repurposing water for beneficial uses. Here are some ways to recycle water in industrial contexts:

• Treatment processes: Wastewater can undergo primary, secondary, and tertiary treatment processes to remove contaminants. This includes mechanical, biological, chemical, and physical treatments to ensure water is safe for reuse.
• Environmental restoration: Recycled water can be used for environmental restoration projects, such as replenishing groundwater reserves, enhancing water security, and supporting ecosystems.
• Industrial processes: Recycled water can be utilised for industrial cooling systems, processing, and other non-potable applications.

By minimising water use through reuse and recycling, industries can significantly reduce their impact on freshwater sources, contributing to sustainable water management.

Harvest rainwater to meet requirements

Harvesting rainwater is an effective way to meet water requirements and reduce industrial pollution of freshwater sources. This method has been practised for thousands of years and is gaining popularity worldwide, with many states and countries encouraging their citizens to adopt rainwater harvesting systems.

Rainwater harvesting involves collecting rainwater runoff and storing it for later use. The traditional way to harvest rainwater is by utilising the roof of a house. The rainwater collects in the gutters and is then directed into a storage device, such as a barrel or a large cistern. More advanced systems may involve connecting gutter pipes to a soaker hose, irrigation pipes, or a hydroponic/aquaponic food growing system.

One of the benefits of rainwater harvesting is that it reduces the reliance on urban infrastructure for water supply. The harvested rainwater can be used for various purposes, including farming, cleaning, washing vehicles, and even drinking, provided it is properly treated and filtered. Additionally, rainwater is generally free of chlorine and has fewer contaminants, making it better for plants and garden use.

Another advantage of rainwater harvesting is its potential to save money on water expenses. By implementing a rainwater harvesting system, individuals can reduce their water bills and become more self-sufficient in terms of water supply, especially in areas with water restrictions or frequent droughts.

Furthermore, rainwater harvesting can help conserve water and reduce the consumption of freshwater sources. This is particularly important in light of global warming and extreme weather patterns caused by greenhouse gases, which are expected to increase water scarcity worldwide. By harvesting rainwater, individuals can do their part in adopting a more eco-friendly and sustainable lifestyle.

In conclusion, harvesting rainwater to meet water requirements is a viable strategy to reduce industrial pollution of freshwater sources. It empowers individuals to take control of their water supply, save money, and contribute to environmental conservation. With the right catchment system, individuals can effectively collect, store, and utilise rainwater for a variety of indoor and outdoor purposes.

Treat wastewater before release

To reduce industrial pollution of freshwater, it is essential to treat wastewater before releasing it into natural water bodies. This process, also known as sewage treatment, involves removing impurities from wastewater before it reaches aquifers or natural bodies of water such as rivers, lakes, estuaries, and oceans. Here are some detailed instructions and considerations for treating wastewater:

Primary Treatment

The first step in wastewater treatment involves physical processes to remove large solid impurities that will either float or settle. Screening, for instance, uses long, closely spaced, narrow metal bars to block floating debris such as wood, rags, and other bulky objects that could clog pipes or pumps. Grit chambers are used to slow down the flow, allowing solids like sand, coffee grounds, and eggshells to settle out of the water. This step is crucial as grit can cause excessive wear and tear on pumps and other equipment.

Secondary Treatment

The next step focuses on removing soluble organic matter and any remaining suspended solids. This is typically achieved through biological processes where microbes consume the organic impurities, converting them into carbon dioxide, water, and energy for their growth and reproduction. There are several methods for secondary treatment, including trickling filters, activated sludge processes, oxidation ponds, and rotating biological contacters.

Tertiary Treatment

Tertiary or advanced treatment is necessary when more than 85% of total solids and biochemical oxygen demand (BOD) must be removed, or when dissolved nitrate and phosphate levels need to be reduced. Tertiary processes can remove over 99% of impurities, producing an effluent of almost drinking-water quality. However, this level of treatment is very expensive and is only used in special circumstances.

Disinfection

Regardless of the level of treatment, disinfection is the final step before discharging the treated wastewater into a natural water body. This step involves destroying any remaining pathogens in the effluent to protect public health. Disinfection is typically achieved using chlorine or hypochlorite chemicals, but ultraviolet radiation is becoming a more competitive method as it leaves no residual in the effluent.

Wastewater Reuse

After treatment, wastewater can be reused for various purposes, such as crop and landscape irrigation, groundwater recharge, or recreational activities. Reusing wastewater helps ease the strain on limited freshwater supplies and improves the quality of streams and lakes by reducing effluent discharges. However, public resistance is often encountered when considering reusing wastewater for drinking, even though it is technically possible with advanced treatment.

Regulatory Compliance

It is important to adhere to local and federal regulations regarding wastewater treatment. In the United States, for example, the Clean Water Act (CWA) prohibits the release of pollutants into navigable waters without a permit. Additionally, pretreatment of industrial wastewater is often necessary to prevent toxic chemicals from interfering with biological processes in sewage treatment plants.

Regulate groundwater use by industries

Groundwater use by industries needs to be legally regulated, especially when there is a threat to groundwater resources. Effective regulation is tailored to the hydrology and economics of the region in question. For example, in the United States, groundwater can be privately or publicly owned. Privately owned groundwater may allow unlimited production, which can lead to overproduction of the aquifer system. This can be mitigated by the government creating regulatory agencies to allocate groundwater rights between competing landowners.

In California, the Sustainable Groundwater Management Act (Sgma) upholds the right to groundwater access and use, but it also considers water a shared asset and imposes rules on its use. This includes the powerful agriculture industry, which uses about 80% of the state's water. Local oversight is provided by groundwater sustainability agencies that are tasked with developing and overseeing groundwater sustainability plans, with the power to gather data and set limits on water pumping.

To reduce industrial pollution of fresh water, it is essential to minimise water use by reusing and recycling it. Industries should also harvest rainwater to meet their water requirements and treat wastewater before releasing it into rivers and ponds.

In addition to regulating groundwater use, industries should also treat chemicals and render them harmless before releasing them into water bodies. They should refrain from releasing hot water into water bodies to reduce thermal water pollution and recycle plastic and glass instead of disposing of them in water bodies.

Install water treatment plants for recycling

Installing water treatment plants at industrial sites is a crucial step in reducing the pollution of freshwater sources. This process involves treating and recycling wastewater, which can then be used for various purposes, such as agriculture, irrigation, and even potable water supplies.

The first step in installing a water treatment plant is to understand the legal requirements and regulations. Off-mains drainage systems are often subject to strict rules, from the type of tank and its placement to discharge locations and ground conditions. A site inspection is then necessary to determine the specific requirements for the system, including any permits, building regulations approvals, or planning clearances needed.

The next step is to design the water treatment system based on the site survey results. This includes sizing the tank and drainage field appropriately and choosing the right tank for the specific needs of the site. The configuration of the treatment system should be done by a professionally trained and qualified expert to ensure it meets all necessary standards and regulations.

Once the system has been designed and approved, the installation process can begin. This typically includes the following steps:

• Examining the tank for any damage and ensuring correct invert depths
• Positioning the tank according to the installation manual's requirements, including any additional conditions or minimum distances
• Considering drainage falls, especially for gravity systems
• Lowering the tank into the hole, ensuring correct inlet and outlet orientations, and levelling it
• Using the appropriate backfill material, such as concrete, gravel, or sand, as recommended by the manufacturer
• Connecting the inlet and outlet pipes, with the potential addition of inspection chambers for easier maintenance access
• Connecting the electrical wires, which should be done by a qualified electrician
• Installing the proper cover and frame, ensuring it meets the specific needs of the site, such as traffic considerations

It is important to note that maintaining and operating the water treatment plant is just as crucial as installing it. Regular maintenance can help identify and address any issues, ensuring the system functions optimally and prolonging its lifespan.

By installing water treatment plants, industries can play a significant role in reducing freshwater pollution. These plants enable the recycling and reuse of water, minimizing the impact on freshwater sources and contributing to environmental sustainability.

Frequently asked questions