A pond filled with dead fish on the outskirts of Wuhan, in Hubei province. About 125,000kg of fish have reportedly died in China
EUTROPHICATION Eutrophication is an increase in the concentration of chemical nutrients in an ecosystem to an extent that increases the primary productivity of the ecosystem. In aquatic ecosystems, eutrophication is caused by excessive inputs of nutrients, both N & P. Generally, freshwaters are P-limited and coastal estuarine waters are N-limited. The nutrients enhance algal growth, and this, in turn, may have a cascade of effects on the ecosystem.
Majority of the urban lakes have already reached a critical stage with their changed hydrological, biological & ecological setting. Therefore, this calls for an urgent stock taking & even reversal of eutrophication process if we have to attempt conservation of lakes. Many ecological effects can arise from stimulating primary production but there are three particularly troubling ecological impacts: decreased biodiversity, changes in species composition and dominance, and toxicity effects. These effects may include: algal blooms, growth of undesirable algal species, oxygen depletion or anoxia in bottom waters, loss of cold-water fish species, abundance of “rough fish”, fish kills, unpleasant tastes and odors.
Encroachment of lakes Most lakes in Bangalore have disappeared due to encroachment & construction activity both by authorizied/unauthorized agencies. The city once had 141 lakes of which 7 cannot be traced, 7 are reduced to small pools of water, 18 have been unauthorisedly encroached by slums and private parties, 14 have dried up and are leased out by the Government. 28 lakes have been used by the Bangalore Development Authority to distribute sites and build extensions for residential areas. The remaining 67 lakes are in fairly advanced state of deterioration. Valley zones of most of these lakes are degenerated resulting in floods during heavy rains
Algal blooms An algal bloom is a rapid increase or accumulation in the population of algae in an aquatic system.algae Typically, only one or a small number of phytoplankton species are involved, and some blooms may be recognized by discoloration of the water resulting from the high density of pigmented cells. phytoplankton
Harmful Algal Blooms A harmful algal bloom (HAB) is an algal bloom that causes negative impacts to other organisms via production of natural toxins, mechanical damage to other organisms, or by other means. HABs are often associated with large-scale marine mortality events and have been associated with various types of shellfish poisonings. Red Tides:- "Red tide" is a term often used to describe HABs in marine coastal areas, as the dinoflagellate species involved in HABs are often red or brown, and tint the sea water to a reddish colour.
Effects of HABs the production of neurotoxins which cause mass mortalities in fish, seabirds and marine mammals human illness or death via consumption of seafood contaminated by toxic algae mechanical damage to other organisms, such as disruption of epithelial gill tissues in fish, resulting in asphyxiation oxygen depletion of the water column (hypoxia or anoxia) from cellular respiration and bacterial degradation
Water Hyacinth Water hyacinth (Eichhornia Crassipes) is an aquatic plant which can live and reproduce floating freely on the surface of fresh waters or can be anchored in mud. It grows in mats up to 2 metres thick which can reduce light and oxygen, change water chemistry, affect flora and fauna and cause significant increase in water loss. It also causes practical problems for marine transportation, fishing and at intakes for hydro power and irrigation schemes. It is now considered a serious threat to biodiversity.
Possible practical applications of water hyacinth The Mennonite Central Committee of Bangladesh has been experimenting with paper production from water hyacinth for some years. They have established two projects that make paper from water hyacinth stems. Another application of water hyacinth is the production of fibreboards for a variety of end uses. The House and Building Research Institute in Dhaka has carried out experimental work on the production of fibre boards from water hyacinth fibre and other indigenous materials.
The fibre from the stems of the water hyacinth plant can be used to make rope. The stalk from the plant is shredded lengthways to expose the fibres and then left to dry for several days. In the Philippines water hyacinth is dried and used to make baskets and matting for domestic use. Biogas production, water purification, animal fodder, fertilisers, fish feed......
Effects of Water pollution
Waterborne Infectious Diseases Typhoid and Intestinal ailments caused by bacteria, parasites, and viruses. Among the most serious parasitic diseases are amoebiasis, giardiasis, ascariasis, and hookworm. In 1993, high cryptosporidium levels in Milwaukee's drinking water supply sickened more than 400,000 residents.
Nutrient Pollution Nutrients: The discharges of nitrogen, phosphorus, and other nutrients coming from agriculture, waste disposal, coastal development, and fossil fuel use. Harmful overgrowths of algae- direct toxic effects –’low-oxygen conditions’ Toxic Algae- "harmful algal blooms," – also referred to as "red tides" or "brown tides.“ Zooplankton eat the toxic algae and begin passing the toxins up the food chain. Nutrient-pollution-driven blooms of non- toxic algae and seaweed –reduction of water clarity
When the algal overgrowths finally die, they sink to the bottom and begin decomposing. This process uses oxygen from the surrounding water. In some cases, the decomposition process takes enough oxygen out of the water that the level falls too low to support normal aquatic life and the region becomes a coastal dead zone. Nutrient pollution can trigger unusual outbreaks of fish diseases. For instance, scientists have found that Pfiesteria, a tiny marine pathogen, can thrive in nutrient-polluted waters. In 1991, one million menhaden fish in North Carolina's Neuse River were killed in a Pfiesteria outbreak. In 1997, several tidal creeks in the Chesapeake Bay watershed experienced Pfiesteria outbreaks, and serious fish kills occurred. Nutrient pollution played a role in both cases.
Chemical Contamination 1.PESTICIDES: In terms of general human health effects, pesticides can : affect and damage the nervous system cause liver damage damage DNA and cause a variety of cancers cause reproductive and endocrine damage cause other acutely toxic or chronic effects The US EPA has found widespread contamination of waterways by Atrazine, the second most commonly used herbicide in the US.
2. MERCURY: Mercury finds its way into water primarily through air pollution from coal- fired power plants and some other industrial processes. In the water, the elemental mercury is converted to methylmercury by certain bacteria, after which it moves up the food chain of fish gobbling each other up. In then end, the larger fish may end up on your dinner plate—swordfish, sea bass, marlin, halibut, or tuna Young children and fetuses are most at risk because their systems are still developing. Exposure to mercury in the womb can cause neurological problems, including slower reflexes, learning deficits, delayed or incomplete mental development, autism, and brain damage. Central nervous system effects like Parkinson's disease, multiple sclerosis, and Alzheimer's disease Bioaccumulation of mercury effects animals in any art of the food chain
Mining 1.Acid mine drainage 2.Spills and leaks 3. Mountaintop Removal Mining WATER POLLUTION EFFECTS OF MINING DISASTERS In 2000, a tailings dam split open at the Baia Mare mine in Romania. This accident sent some 100,000 tons of wastewater and 20,000 tons of sludge contaminated with cyanide, copper, and heavy metals into the Tisza River, and eventually into the Danube—destroying 1,240 tons of fish and polluting the drinking water supplies of 2.5 million people. In 2008 in the US state of Tennessee, an impoundment dam failed and 5.4 million cubic yards of coal ash spilled into adjacent waterways, killing fish, damaging property, and threatening drinking-water supplies. Residents now face concerns about the long-term health effects from the ash, which contains numerous harmful contaminants such as arsenic. It should be noted that in this case the spill was not related to coal mining; it was stored coal ash, the waste that results from burning coal in a power plant.
THERMAL POLLUTION Industrial thermal pollution is a problem for our waterways—fish and other organisms adapted to a particular temperature range can be killed from thermal shock, and the extra heat may disrupt spawning or kill young fish. Warmer water temperatures lower the dissolved oxygen content of the water. That's a double-whammy to aquatic organisms, since the warmer water also causes them to increase their respiration rates and consume oxygen faster Global warming is imparting extra heat to our oceans, which have absorbed about 20 times as much heat as the atmosphere over the past half-century
LETS HAVE A LOOK AT ONE OF THE WELL-KNOWN RIVERS OF INDIA !
Dolphins die as the Ganga chokes Over a 100 factories in this UP belt empty toxic effluents into the Ganga Effluents once released into the Ganga choke all life forms gradually. Reports available show high levels of the pesticide DDT found in the carcasses of dead dolphins. Over 50 dams and barrages have been built all along the Ganga and water has been diverted for agriculture. Dams create physical barriers that prevent migration of the dolphins leading to inbreeding. The river is only three feet deep in this region and so the water level is too little making the dolphins isolated in shallow pools.
Case Study I- Different approaches to solve Fresh water pollution problem in India and China
Tripur A drought prone area (designated by the Government of India) Clean water is crucial for the dyeing and bleaching units. Textile dyeing industries discharge effluents ranging between 80 and 200m 3 /t of production. Severe water crisis due to over extraction of groundwater and contamination of groundwater and other surface water bodies. The effluents have a high Biological Oxygen demand (BOD), Chemical Oxygen Demand (COD), color and salt content. The Common Effluent Treatment Plants (CETPs) and Individual Effluent Treatment Plants (IETPs) set up by the industry do not reduce the Total Dissolved Solids (TDS) in the effluents. Effluent with high salt content is discharged into the River Noyyal which then flows downstream to be stored at the Orathupalayam reservoir, which in turn impacts the agricultural lands irrigated by these waters.
Tianjin An extremely water-scarce area. The quantity of surface water per capita is only 322m 3, less than one fifteenth that of China. High economic growth has put an additional stress on the water resources. Due to the lack of water, paddy fields are converted into glebes, wetlands are transformed into saline lands, and subsidence is significant due to the over-extraction of underground water.
Options available Transfer water from other areas Reuse the treated wastewater for industrial, municipal, agricultural or residential purposes. Desalinate seawater (Tianjin) The optimum level of pollution causing activity is the point where the social benefits are slightly more than the social costs.
Tripur Approach New Tirupur Area Development Corporation Limited PPP based on BOT model Project-specific public limited company for water and sewerage with equity participation of major beneficiaries First concession by a state government to a public limited company to draw raw water for domestic and industrial uses and to collect revenues First index-based user charges and direct cost recovery for urban environmental services First investment of IFC in the water sector in the country. Pipeline from the Cauvery river, a water distribution network of about 350 km.
Tripur Approach Raw water and sewerage treatment plants, pumping stations, and conveyance facilities. A water treatment plant is located at the water source. The project cost is to be financed through a debt: equity ratio of 1.5:1 viz Equity - 322.70 Crores, Subordinate Debt - 86.50 Crores, Debt - 613.80 Crores. NTADCL charges differing prices for water used for domestic purpose and water used for industrial use. The charges are Rs. 3 per kilolitre (KL) for villages, Rs. 5 per KL for domestic use in the Tirupur Municipality and Rs. 45 per KL for industrial and commercial consumers.
Environmental Cost The O & M cost of sewage reclamation plant may be about Rs. 8/KL and hence the total water pricing of domestic water ought to be about Rs. 11 to 13/KL (water supply cost of Rs. 3/KL or Rs. 5/KL, reclamation cost of Rs. 8/KL) and Rs. 80/KL (i.e.water supply cost of Rs. 45/KL as per NTADCL estimation and Rs. 35 /KL for RO +Evaporator +Crystaliser O & M costs).
Environmental Cost “zero discharge” levels specified by Tamil Nadu High Court. If, nearly 95% of the water taken is effectively recycled and reused, it would strike a huge blow to the effective functioning of NTADCL, which can only survive and make profits, if there is a consistent and upward demand for the water supplied.
Tianjin Approach Research showed that if urban wastewater is treated to act as living water, the basic construction cost of the treatment facility will equal that of diverting water from 30 km away; if it is to act as treating technical water, the cost will equal that of diverting water from a 40–60 km distance (Hu, 1999). The content of impurities in urban wastewater is usually less than 0.1%, and they can be eliminated through a treatment process. However, seawater contains dissolved salts and organic substances, which take up 3.5% of volume and impurities are over 35 times that of urban wastewater.
Tianjin Approach Centralised treatment and reuse of urban wastewater is a systematic project that regroups various agencies in urban planning, industry, agriculture, irrigation works, environmental protection, municipal engineering, hygiene, etc. A supervisory agency should include professional expertise in hygiene, environmental protection, agriculture, supervision, etc. It will supervise and manage pollution sources, irrigation water quality, agricultural products according to national standards, prohibits the irrigation by untreated wastewater and the use of sludge. Helping the water-supplying agency to manage water resource uses and set corresponding monitoring procedures.
Case Study II- Loopholes exploited by some distilleries in India and need for load based Cess
Legal provisions available Water (Prevention and control of pollution) Act-1974 Water Cess Act-1077 Environmental Pollution Act-1986 Discharge of wastewater carrying pollutants above specifies concentrations is prohibited. However no penalty on the volume of water discharged
Water Cess Act Groundwater consumption is metered and cess is charged, serves as a free source of income for the municipalities. Differential charges- The price of water does not cover its opportunity cost or scarcity value
Unethical practices The Effluent profile for Distillery industries is characterized by high BOD levels. The cost function follows a negative exponential curve. It is cheaper to dilute effluent with freshwater and discharge rather than do the primary, secondary and tertiary treatment.
Load based Cess Quality and volume of effluent varies from Industry to industry Load based industry standards obtained by research A distillery producing 10,000 Kl of alcohol annually requires 250,000 Kl of fresh water. Extra water used indicated inefficiency or malpractice.
Case Study III- Treatment options available for municipal sewage
Primary Treatment stages Activated Sludge Process Trickle Bed Filter Upflow anaerobic sludge blanket
Anaerobic Digesters Anaerobic digestion is a series of processes in which microorganisms break down biodegradable material in the absence of oxygen and is widely used to treat wastewater The two main byproducts are CH 4 and methanogenic digestate
Financial and Economic benefits The byproducts can act as a source or revenue. The additional revenue due to sale of methanogenic digestate and biogas reduces the break-even time and increases the Net Present Value.
Once upon a time in Japan From 1932 to 1968, Chisso Corporation, a company located in Kumamoto Japan, dumped an estimated 27 tons of mercury compounds into Minamata Bay. Kumamoto is a small town about 570 miles southwest of Tokyo. The town consisted of mostly farmers and fisherman. When Chisso Corporation dumped this massive amount of mercury into the bay, thousands of people whose normal diet included fish from the bay, unexpectedly developed symptoms of methyl mercury poisoning.
W.Eugene Smith The first environmental pollution photojournalist