Water Pollution: Understanding Acidic And Basic Contamination

Water pollution is a pressing issue that affects the entire planet, and one of its key aspects is the alteration of water's pH levels, making it either acidic or basic. The pH scale, ranging from 0 to 14, determines how acidic or basic a substance is, with 7 being neutral, values below 7 acidic, and above 7 basic. Water's pH levels can be influenced by both natural processes and human activities, with the latter often causing significant harm to aquatic ecosystems and even human health. Understanding the causes and consequences of acidic and basic water pollution is crucial for mitigating its impacts and preserving the health of our planet and its inhabitants.

Carbon dioxide, industrial pollution, and acid rain

Carbon dioxide is the most common natural cause of acidic water. It is responsible for the slight acidity of normal rain, which has a pH of about 5.6. This happens when carbon dioxide dissolves into the rain, forming weak carbonic acid.

However, when it comes to industrial pollution, the burning of fossil fuels, coal, and oil in factories, power plants, and refineries is a significant contributor to acid rain. These industrial processes emit sulfur dioxide (SO2) and nitrogen oxides (NOx) into the atmosphere, which then react with water, oxygen, and other chemicals to form sulfuric and nitric acids. These acids mix with precipitation and fall to the ground as acid rain. Acid rain typically has a pH between 4.2 and 4.4, which is significantly more acidic than normal rain.

In addition to acid rain, industrial pollution can also lead to acid runoff and acidic groundwater seepage. This is particularly common in coal mining operations, where the surrounding soil and water can become contaminated with acidic compounds if they are not properly buffered. This acidic water can then flow into nearby water sources, such as wells and groundwater systems, leading to acidic water conditions that can have negative consequences for the environment and human health.

The effects of acid rain and industrial pollution are far-reaching and detrimental. Acid rain can harm soil, forests, streams, and lakes, impacting the flora, fauna, and natural resources that depend on these ecosystems. For example, acid rain can make lakes more susceptible to climate impacts and create conditions that are harmful to fish populations. Additionally, acidic water can corrode pipes and plumbing, and it may contain high levels of heavy metals, which can lead to health issues for humans if consumed.

To mitigate the effects of industrial pollution and acid rain, it is crucial to transition to renewable forms of electricity generation, such as wind, solar, and hydropower. By reducing the burning of fossil fuels and coal, we can minimize the emissions of pollutants and toxins that contribute to acid rain and climate change. Additionally, implementing measures to treat and neutralize acidic water, such as using acid-neutralizing filters, can help reduce its negative impacts on the environment and human health.

Agricultural and industrial runoff, wastewater discharge

Agricultural and industrial activities have a significant impact on water quality, as these practices often result in the release of pollutants into water bodies. This can lead to changes in the pH of the water, making it more acidic or basic, which can have detrimental effects on aquatic ecosystems.

In agriculture, the use of chemicals such as fertilizers, pesticides, and herbicides is common. These chemicals can be

Effects on ecosystems, including fish and plant life

Water with a high level of acidity or basicity can have detrimental effects on ecosystems, including fish and plant life. Firstly, it is important to understand that different aquatic species have varying pH tolerance levels. For instance, koi fish thrive in waters with a pH of 7.5 and can withstand pH levels of up to 8.2, whereas Oscar fish prefer a more acidic environment with a pH of 6.5-7, and African Cichlids favour a basic pH of 8.5. Young fish are more vulnerable to acidic water than adult fish, and water with a pH of 5 will kill fish eggs, preventing them from hatching.

In terms of the impact on fish, the pH level of the water can have a direct effect on their skin. If the water is too acidic, it can burn the fish's skin, and if it is too basic, it can cause chapping or chemical burns. Additionally, low pH water can contain high amounts of heavy metals, which can lead to heavy metal poisoning or toxicity in fish.

The pH level of water also influences plant life. Studies on tree peonies have shown that exposure to both acidic and alkaline conditions causes an excess accumulation of reactive oxygen species, which damages the plants and inhibits their growth and development. The nutrient assimilation process is disrupted, and the synthesis of chlorophyll genes is suppressed, resulting in reduced chlorophyll content. Moreover, the development and structure of stomata and chloroplasts are affected, impairing the plant's photosynthetic characteristics.

While acidic water has negative consequences, it is important to note that some sources suggest that acidic water can have benefits for plant growth in certain contexts. For example, spraying tomato seeds with acidic electrolyzed water effectively reduced bacterial pathogens without hindering the growth of the seeds. Therefore, while acidic water can have detrimental effects on some plant species, it may have potential applications in agriculture for pest control and promoting the growth of certain plants.

In summary, the pH level of water is crucial for the health of aquatic ecosystems. Deviations from the optimal pH range can result in skin damage for fish and impaired growth for plants. The presence of heavy metals in acidic water further exacerbates the risks for both fish and plant life.

Heavy metal contamination and health risks

Water can become acidic due to natural processes like precipitation, photosynthesis, respiration, and decomposition. Carbon dioxide is the most common natural cause of acidic water. However, it can also be caused by anthropogenic pollution, such as burning fossil fuels, which causes acid rain. Acid rain occurs when rainfall chemically interacts with nitrogen oxides, sulfur oxides, and other acidic compounds, making the rain more acidic.

Acidic water has a pH of 6.5 or less and can be caused by natural phenomena as well as industrial pollution. It often contains high amounts of heavy metals, which can have several negative health consequences. Heavy metal contamination has been linked to various health risks, and the adverse effects on human health have been regularly reviewed by international bodies such as the WHO.

Heavy metals such as lead, cadmium, mercury, and arsenic pose significant threats to human health. These metals have been linked to neurological damage, kidney damage, bone issues, and an increased risk of certain cancers. Long-term exposure to heavy metals can lead to physical, muscular, and neurological degenerative processes that resemble diseases like multiple sclerosis, Parkinson's disease, and Alzheimer's disease.

Arsenic, one of the most abundant elements on Earth, is a prominent toxic and carcinogenic heavy metal. It is extensively available in the form of oxides, sulfides, or as a salt of iron, sodium, or calcium. Arsenic contamination can occur through natural geologic processes or human activities such as industrial sources or the inappropriate disposal of arsenical chemicals. Exposure to arsenic is mainly through food and drinking water, with food being the most common source for most populations. Long-term exposure to arsenic in drinking water is associated with increased risks of skin cancer and other skin lesions.

Cadmium exposure, on the other hand, is majorly attributed to cigarette smoking in smokers, while food is the primary source of exposure for non-smokers. Recent data suggest that adverse health effects from cadmium exposure may occur at lower levels than previously thought, with kidney damage being a primary concern.

Mercury exposure is another significant health risk associated with heavy metal contamination. The general population is exposed to mercury primarily through food, especially fish, which can contain methyl mercury. High fish consumption has been linked to potential neurological damage in adults. Additionally, certain groups, such as pregnant women, are advised to avoid fish known to have high mercury levels, such as shark, swordfish, and tuna, to prevent potential harm to the fetus.

To mitigate the health risks associated with heavy metal contamination, various public health measures have been implemented to control, prevent, and treat metal toxicity. These measures address different exposure routes, including occupational exposure, accidents, and environmental factors.

Treating acidic water and neutralising pH

Water with a pH value of 7 is considered neutral, and represents a balance between the amount of acid and base in the water. Under the EPA's drinking water standards, there is no primary standard for pH, but it is recommended that drinking water pH fall between 6.5 and 8.5.

Public water systems are treated to ensure that the water delivered to residential homes has a neutral pH. However, private well owners are at the mercy of the groundwater and aquifer system from which they draw their water. The most common regions for acidic water conditions in the United States are New England, the Mid-Atlantic, and the Pacific Northwest. The main influence on low pH in these regions is free carbon dioxide, mineral acids, and the lack of sufficient bicarbonate alkalinity.

Alkalinity is a measure of the water's ability to buffer itself or neutralize acids. A higher alkalinity results in a greater capacity of the water to resist changes in pH from the addition of acids. The alkalinity of a stream or other body of water is increased by carbonate-rich soils (carbonates and bicarbonates) such as limestone, and decreased by sewage outflow and aerobic respiration.

There are several ways to treat acidic water and neutralise pH:

• Acid neutralizing filters: This is one of the best ways to neutralize the pH level in the water. In this method, the water flows into a pressurized tank containing calcium carbonate (often called calcite). Since the water absorbs these minerals, the alkalinity and hardness increase. This method works well for water that has a pH of 5.5 or higher.
• Liquid chemical solution: Feeding a liquid chemical solution directly into the water (e.g. soda ash injection).
• Passing the acidic water through a bed of neutralizing media (e.g. calcite or magnesium oxide).

Other methods of treating acidic water include:

• PH correction
• Chemical pump systems
• Using acidic water for cleaning fruits and vegetables
• Using acidic water for plant growth

Frequently asked questions