Title : Phytoremediation of Heavy Metals laden Waste Water using Duckweed species
INTRODUCTION
Presservation of the environment quality is one of the major concern of this century. Our biosphere is getting degraded by the release of natural and synthetic substances that can cause deleterious effects on living organisms. Among all the pollutants , heavy metals are easily transported and accumuted in the environment. Many industries like textile and steel, electroplating, metal producing release heavy metal such as cadmium, copper, chromium, nickel and lead in the wastewater (Demirenzen et al., 2007). Most of the heavy metals are toxic or carcinogenic in nature and pose a threat to human health and the environment (Shakibaie et al., 2008; Vinodhini and Narayanan, 2009).
Several conventional methods are used for the removal Heavy metals from wastewater includes chemical precipitation, ion exchange and reverse osmosis etc. but major drawbacks with such treatments are produces large amount of sludge and may be ineffective or expensive processes. So, the search for a new, simple, effective and ecofriendly technology involving the removal of toxic heavy metal from wastewater has directed attention towards phytoremediaton( Divya Singh et al., 2012).According to UNEPPhytoremediation can be defined as “the efficient use of plants to remove, detoxify or immobilise environmental contaminants in a growth matrix (soil, water or sediments) through the natural biological, chemical or physical activities and processes of the plants”. The ideal plants for phytoremediation should possess the ability to tolerate and accumulate high levels of heavy metals in their harvestable parts, while producing high biomass. Many species of macrophytesare used f...
... middle of paper ...
...sal.Phytoremediation technology has proved to be a viable option to purify water contaminated with trace elements since it is cost-effective and has a positive impact on the environment.In the present study the efficiency of duckweed as an alternative cost effective natural biological tool in wastewater treatment in general and eliminating concentrations of heavy metal present in industrial wastewater was examined in lab conditions. This is an alternate technology in which small scale wastewater treatment can be achieved. It has been used recently in Bangladesh for wastewater treatment as well as this technology has been implemented at village level under UNDP project. More research through pilot projects is needed in order to refine the sizing of the ponds used and to determine the correct innocculum of plant material to achieve a predetermined effluent quality.
What is a pesticide?A pesticide is a chemical substance used to kill pests, especially insects. A pesticide is also refered to as a biocide. Most pesticides are applied in spray form but occasionaly you will see pesticides that are in powder or pellet form. Pesticides are used on a variety of things, anything from crops like corn, barley, and wheat, to plants like petunias, marigolds, and rhodadendrons, which are usually found in small gardens greenhouses, and even in your backyard.
Heavy metals are characteristic parts of the Earth's covering. They can't be debased or destroyed. To a little degree they enter our body by means of drinking water, food and air. As follow components, some substantial metals (e.g. copper, selenium, zinc) are crucial to look after the metabolism of the human body. At higher concentrations they can accelerate poisoning. Devastating poisoning of metals arise from drinking-water pollution (e.g. lead channels), high surrounding air fixations close to emission sources, or through food chain.
Drinking water contaminated bt lead is not a new problem. Lead was authentically used to produce pipes. It is an universal metal that has been used throughout the years, as a fundamental component in various products such as radiation, shielding, plumbing, gasoline, ceramic glazing, children’s toys, and paints. Its long history of use and distribution means lead exposure and its health effects are
Water is an essential part of life for any living organism in the world. People use water every day to drink, do daily housework, or to bathe in; while animals use water to survive. Because of the doings of humans, the water that is so essential to all organisms’ well being is being polluted. The water drink and use every day may have oil from large petroleum companies spilling into it. Debris from sewer plants float into the ocean when they overflow. Even prescription pills are contaminating the water. Not only is the water affecting the humans that drink it but also affects the aquatic life. Aquatic species may have problems reproducing which disrupts the whole food chain and biodiversity web of life. How water becomes contaminated should
China is becoming one of the increasingly crucial environmental concerns of heavy metal contamination on agricultural land. Heavy metal contamination happens when water resources are short and wastewater is then applied to plants causing major health risks to environmental quality and food production. Many scientists have been exploring solutions of this environmental problem and some research say that mycorrhizae have made a positive outcome in fighting the heavy metals and toxins in the soil. Heggo,A. (1990) studied the mechanism of mycorrhizae and heavy metals and resulted that mycorrhizae fungi may filter excessive metals in the soil. Another study showed that mycorrhizae enhanced tolerance of plants infected with toxic soils. Scientists are still studying to find out ways how mycorrhizae fungi improve these plants and resistance from heavy metals. However, metal and toxin uptake might be also impacted from the soils condition. Mycorrhizae symbiosis are well familiar for their enhancement of phosphorus uptake. This nutritional benefit is questioned to account for the plants tolerance of heavy metals and toxins in the soil. The way that heavy metals and toxins affect the ecosystem is the life of organisms such as plants don’t grow in a healthy manner causing toxic plants where animals and humans can
Growing food with Aquaponics is more efficient than growing food the traditional soil garden way. In a typical soil garden, growers end up spending hours of their time doing back breaking work on their garden, but not anymore, with Aquaponics the need for any tilling, digging, or weeding is eliminated. Aquaponics combines Aquaculture (Raising fish in tanks), and Hydroponics (Growing plants without soil). The outcome is a working system that provides plants with all the nutrients they need, while using a minimum of space, effort, water, fertilizers, and pesticides. Aquaponics allows farmers to use up to 90% less water than normal farming would use, so instead of watering your soil and having the majority of your water either lost by run off or evaporated by the sun, the water is recycled repeatedly through the system saving farmers hundreds of dollars on their monthly water bills. Also when growing with Aquaponics, much more food can be produced in a smaller space, in some cases growers have produced around twenty times the amount of produce in the same area a soil garden would. In addition, with the closed, controlled environment of the system, the need for the use of any pesticides a basically eliminated. Finally, Aquaponics enables growers to grow bigger, better and more quality produce.
Lead is a naturally occurring metal used in various industrial goods from pipes, paints, and well linings. Lead is a greyish heavy metal that is harmful if swallowed or breathed in. Lead can be handled without gloves, but should be limited and a thorough hand cleaning is needed afterwards 1. Lead originates from the Greek word “Protos”, which means first 2. Lead is known to be introduced into groundwater by contact with old lead pipes, runoff of lead based paint, leaded gasoline leakage, and automobile air emissions 3. Lead poisoning can greatly affect people such as “brain and nervous system damage, and particularly mental development impairment in children; reproductive system interference including effects such as premature infant and low births; circulatory system damage such as O2 absorption decrease and increase in blood pressure; and kidneys malfunctioning” (Kinder, 1997) 4. Lead contamination can be found anywhere lead is used or refined. As it is a naturally occurring metal, lead tends to seep into the ground easily with the assistance of water and its abundant use in manufacturing. Lead is transported into the system mainly by leeching by contact into the water source by older lead pipes, fittings, and various lead lined containers 5. Currently there is no other viable way to remove lead contamination from groundwater other than to pump and treat either in mass quantities or through reverse osmosis, distillation, or carbon filters 6. The main course of action and most reliable is to remove the source of the lead from contact with water 7.
E-wastes are including many dangerous chemicals, such as, cadmium, beryllium, and mercury. Therefore, when we disposal the e-waste in the wrong way, these toxics have a high risk of air pollution, soil contamination and absorb into the water. For instance, in Guiyu villages (China), has the highest dioxin in the world, which can cause cancer. In the villages, seven out of ten children have a numerous lead in their body because of the water is polluted (Levin, 2010). Furthermore, according to Lincoln University (New Zealand), these toxic from e-waste can come through the “soil-crop-food-pathway”. These toxics are not able to disintegrate, they exist in the environment for the long time and the risk of exposure will be increased (McAllister, n.d.). Moreover, in several countries, to provide the family income; some people need to work with the e-waste every day (Honorine, 2010). Thus, e-wastes are not only the economical problem. They are also affect the environment and human
Background: Waste water treatment plants are essential to communities of all sizes and must work efficiently. Waste water treatment plant primary priority and responsibility is the treatment of incoming sewage water by the removal of biological and chemical wastes so it can be treated and recycled for future use. There are many government agencies and standards set forth to govern and observe the successful treatment of sewage, such as the Department of Environmental Quality, the National Pollutant Discharge Elimination System and the Clean Water Act of 1972. Compliance and constant monitoring of the treatment plant’s operations are important as they protect the surrounding community. A spill or backflow of sewage due to a complete system malfunction could potentially be detrimental to the environment and local community.
The main sources of water in Bhutan are natural spring water, natural rivers/streams and deep groundwater and water quality is reported as first class conditions expect at localized urban areas. Four major river sinks are Amochhu, Wangchhu, Punatsangchhu and Manas. The main activities that cause water pollutions in Bhutan are ongoing development and human actives such as urbanization, rapid growth of population, more hydro electric projects construction and other infrastructure development and industization activities which produce huge amount of waste leading contamination of water bodies in the country degrading quality of safe drinking water of the nation. Human waste and solid waste dumping in the rivers and urbanization waste water.
Phytoremediation is a novel, efficient, environmentally friendly, low-cost technology, which uses plants and trees to clean up soil and water contaminated with heavy metals and/or organic contaminants such as solvents, crude oil, polyaromatic hydrocarbons and other toxic compounds from contaminated environments. This technology is useful for soil and water remediation.
There are countless sources of water pollutions that exist today due to our industrious and technologically advanced lifestyles. However, the most vexing is caused by the most basic necessity for survival, Agricultural Pollution. Agricultural Pollution is defined as, “ liquid and solid wastes from all types of farming activities, including run-off from pesticide and fertilizer use, and from feedlots; erosion and dust from ploughing; animal manure and carcasses; and crop residues and debris. In essence Agricultural Pollution is a nonpoint source water pollutant since it comes from various locations and cannot be pinpointed” (EPA-web). Although there are many practices already in place that will decrease the pollution, increase productivity, and save farmers money in the long run, the farmers are careful to change practices.
The final phase of research (2009-2012) will look at how phytoremediation plants might be able to produce materials such as precious wood, fibres, chemicals, essential oils, dyes, gums, and recoverable minerals and metals for secondary industries, and thus help local communities.
Water pollutants are of different types such as oxygen demanding wastes, disease causing agents, synthetic organic compounds, plant nutrients, inorganic chemicals and minerals, oils, thermal discharge and radioactive wastes. Of all these water pollutants, heavy metals and synthetic organic compounds cause majority of water pollution. Industries like paper and pulp, tanneries, textiles and coke ovens, pha...
Indira, K., and Romit, S. n.d. Drinking water quality in rural India: Issues and approaches. http://www.waterawards.in/suggested-reading/wateraid-drinking-water-quality.pdf (accessed November 10, 2010).