water pollution chemistry assignment help

water pollution chemistry assignment help

The Chemistry of Water Pollution: Understanding the Causes, Effects, and Solutions

1. Introduction to Water Pollution

The chemistry of water pollution includes issues as complex as global climate change (including ocean acidification), where inorganic pollutants are playing a part, to the local transfer of trace contaminants such as perfluorinated alkyl acids (PFAAs). The intersection of chemical contaminants with biological and ecological systems is a critical bridging concept as we move to address emerging organic pollutants present at the low nanograms/liter level in water. Additionally, background contamination (from runoffs and the like) is at much higher concentration than for new compounds. Water pollution can cause health effects that range from, at the least, having the sense of despair from the altered habitat, all the way to shortened life expectancy for children and adults whose water supplies are contaminated with even the merest hint of chemicals. As scientists, we develop the tools and understanding to address these issues, and as people concerned for the welfare of the planet, we look to others for innovative solutions to short-circuit the accelerating intake of contaminants through improved water treatment, improved environmental corrosion resistance, and development of benign-by-design products.

Water supplies around the world are depleting in both quality and quantity, with concerns rising about the potential for social and political conflict. Consequences have the potential to be severe, with up to 60% of the world’s population projected to be affected by an acute water shortage by 2025. Waterborne illnesses are equally dire. It is estimated that at any one time, almost half of people in developing countries are suffering from diseases caused by inadequate water and sanitation facilities, which kill more than 5 million people every year. Yet water pollution seldom precludes human contact and usage. Comprehensive understanding of causes, effects, and solutions requires an exploration of the underlying chemical impacts.

2. Chemical Pollutants in Water

This chapter will start by discussing the behaviour of some of the main chemical species or classes of chemical species that are pollutants in the aquatic environment. In turn, we will consider (in this section) the following attributes of pollutants: their source, either as a prime source or as a constituent of mixed effluents from a specific industrial, agricultural, or domestic activity; their mobilization into aquatic environments, as a result of rainfall, leaching, surface run-off, and air-borne deposition; their behaviour during transport, as dissolved constituents in the water, or as sorbed species in fine particulate matter; the possible effects of these sorption processes in reducing the bioavailability or toxicity of the dissolved constituents; and the potential pathway for release back into the aqueous environment (desorption). Finally, the implications for the quality of surface water are considered. In order to provide a comprehensive overview of the distribution of pollutants, further consideration is given to their fate, either as modified species, or not modified species, during transport and degradation in the different water types.

The number of chemical pollutants that contaminate water is vast. Each of these is a potential hazard to health or the environment or both. Each has its own chemistry, its own sources, and its own fate in the water system. Assessment of the hazard of water pollution requires detailed information on each class of chemical pollutant. It is probably accurate to say that the danger posed to water quality by chemicals is comparable to, or even greater than, that represented by microbial pathogens. The importance of micropollutants should not be underestimated.

3. Impact of Water Pollution on Ecosystems and Human Health

Pollutants from wastewater can be a very serious health risk due to the potential ingestion of hazardous compounds by the consumption of drinking water and organisms bound to these. Human health can be affected directly through consumption of polluted drinking water. Several biological agents can also be present in the water, affecting the health of humans and aquatic species living in it. Toxic substances tend to be much more toxic to the natural aquatic flora and fauna and by biomagnification, the severity of water pollution effects increases. Contaminated sea life upsurges the malevolence and extent of water pollution; aquatic products are prone to bio-amplify heavy metals. In this view, water pollution poses a serious and adverse threat worldwide.

Ecosystems are based on the environmental quality of water. Polluted water disrupts the assimilatory capacity of an aquatic ecosystem, rendering it unsuitable for healthy and normal flora and fauna. The consequences of water pollution include the reduction of biodiversity, loss of habitat, excessive growth of harmful algae and weeds, depletion of oxygen levels in the water systems leading to death of aquatic species, transmission of waterborne diseases, etc. Water pollution also affects human health both directly and indirectly. The major diseases contributing to death in developing countries like cholera, dengue fever, hookworm, amoebic dysentery, giardiasis, jaundice, typhoid, etc., are due to consumption of contaminated water. The more toxic substances like pesticides, heavy metals, and plastics are able to avoid any immediate damage to human health but hasten through indirect pathways because the pollutants get accumulated in aquatic organisms and human beings by consuming aquarium animals, plants, etc., for more prolonged periods.

4. Analytical Techniques for Detecting and Monitoring Water Pollution

There are several purposes to monitoring water quality, including ensuring it is clean and safe for drinking and irrigation, and for use in industrial processes. The water environment may need to be preserved for the aesthetic pleasure it gives people, and in order to provide habitats for a variety of plants and animals, to preserve mutagenic hotspots, and/or to remove or neutralize toxins. It is appropriate to determine whether the water quality standards laid down by governments and other organizations are being met, e.g., with reference to laws set by individual countries. In order to achieve these stipulations, there is a high level of sophistication in the techniques and instruments used to assess and monitor water quality. These state-of-the-art technologies allow a greater knowledge as to the concentration and identity of pollutants in the water column (i.e., the sediment and the overlaying water).

Whereas section 3 identified the main contaminants in freshwaters, part 4 concentrates on the chemical analysis of pollutants themselves. Broadly, chemical analysis involves two processes: qualitative work to identify the components of a mixture, followed by quantitative work to measure the concentrations of the various components. Some of the instrumental-scientific methods of analysis are very expensive, in terms of the equipment and the costs of consumables and disposables; at most of the sites we consider, real-time detection methods are not employed, as the cost is prohibitive. Here, we describe the range of analytical methods.

5. Innovative Solutions and Future Directions

Many plant systems, including Azolla filiculoides and Juncus effusus L., have been widely employed for the removal of heavy metals from polluted sediments and water bodies. However, further research is required to optimize the selection of plant species and how the influential factors of the plant systems work. Increasing research is focusing on the use of innovative environmentally friendly adsorption materials to remove a variety of pollutants from water. Several sustainable management strategies are being developed to minimize nonpoint source pollution, including the use of a green sewage swirl filter to capture nitrogen and phosphorus, and the Huanghan harrow and groove fertility system for doline headwater areas. Policymakers cannot afford to wait for every research question to be answered. Some of the most difficult decisions related to water pollution are regulatory, not scientific. Policymakers and government agencies must implement new policies and identify new methods. Collaboration between scientists, industry, the private sector, and government policymakers is required for the development and implementation of safer substitutes for toxic chemicals. Funders should support interdisciplinary efforts to address this complex problem. The development of easy-to-use technology that can inform residents of the water quality in their vicinity without relying on government-provided data is an area that would benefit from greater attention. Government and industrial wastewater treatment plants should implement zero liquid discharge to improve water quality.

There are several innovative solutions being investigated to prevent and mitigate water pollution. Advanced and affordable sensing technologies have been developed to make real-time detection of water pollutants possible. Inexpensive electrochemical devices with sensors can measure pH values, levels of heavy metals, and chemical oxygen demand (COD). The technology is efficient in detecting organic and inorganic compounds in water and has potential industrial applications. Big data and emerging technologies (e.g., IoT, artificial intelligence (AI), and fluorescence sensors) have significantly contributed to the observation and prediction of chemicals and biological parameters in natural surface waters over time and space. The use of innovative floating wetland structures or rafts in constructed or natural waters are being considered to support and balance the bacterial community. Such systems leverage bacteria to consume nutrients and could be useful for agricultural water reuse, nonpoint pollution sources, farm ponds, and possible hyperspectral approaches for mapping algal blooms.