WEEK 16, TOPIC 14

Water and Wastewater; NOT INCLUDED: WAYS ON CONSERVING WATER

Water

¾ of the earth is covered with this; the presence of a large amount of _____ makes our planet special and unique; a person can live for 7 days without food but not without _____; one of the most important properties of this is to support life, but it is very easy to be polluted.

• Disease-causing Agents

• Oxygen-demanding Wastes

• Water-soluble Inorganic Chemicals

• Inorganic Plants Nutrients

Causes of Water Pollution

Disease-causing Agents

These are the bacteria, viruses, protozoa, and parasitic worms that enter water from domestic sewage and untreated human and animal wastes that can cause cholera, typhoid, and gastrointestinal diseases.

Oxygen-demanding Wastes

These are organic wastes that can be decomposed by aerobic bacteria.

Municipal Sewage

This is an obvious oxygen-demanding waste. It is the wastewater of communities and the water collected by sewer pipes coming from homes and factories. It carries many types of waste, including human feces.

Water-soluble Inorganic Chemicals

These are heavy metals like mercury, lead, cadmium, chromium, and arsenic.

Mercury

When this is discharged from an industrial plant into rivers and streams, it is converted into methyl _______ by the action of bacteria; contaminated fish also become contaminated.

Methyl Mercury

This is a strong poison that is taken by small fishes and other living animals.

Minamata Disease

This mercury poisoning may not appear for months. Victims suffer excessive fatigue, headache, amnesia or loss of memory, impairment of speech, and disturbance of muscle coordination.

Cadmium

This kind of poisoning can cause itai-itai disease, in which bones become brittle.

Lead

A toxic metal used in battery making, smelting, and plumbing paints.

Inorganic Plants Nutrients

Elements like nitrogen, phosphorous, and potassium that are essential for plant growth are found in domestic wastes, detergents, and fertilizer runoffs and cause overgrowth of algae and water plants in rivers and lakes.

Dinoflagellates

Microscopic algae that can grow uncontrollably when nitrates and phosphates are high.

Red tide

A phenomenon caused by blooms of dinoflagellates (mainly Pyrodinium bahamense) turning water red or reddish-brown.

Saxitoxin

A potent neurotoxin produced by dinoflagellates that blocks nerve impulses, leading to paralysis; the most abundant and most toxic.

Paralytic shellfish poisoning (PSP)

Illness from eating shellfish contaminated with saxitoxin; symptoms include numbness, headache, nausea, and weakness.

Cooking or boiling does not destroy saxitoxins and may even enhance their toxic effects. Death may occur about 12 hours after ingestion.

• Increasing population

• Rising demand by agriculture, industries, and cities

• Urban use and waste of water

• Unequal distribution of water

• Pollution

Reasons for Severe Water Shortage

RA 9275

The Philippine Clean Water Act of 2004 aims to protect the country’s water bodies from pollution from land-based sources (industries, agriculture, commercial establishments, and households). It provides a comprehensive and integrated strategy to prevent and minimize pollution through a multi-sectoral and participatory approach involving all the stakeholders.