Soil, marine ,noise and thermal pollution By Ramphal Bura

Soil Formation of soil from the parent material (bedrock): mechanical weathering of rocks by temperature changes, abrasion, wind, moving water, glaciers, chemical weathering activities and lichens. Under ideal climatic conditions, soft parent material may develop into 1 cm of soil within 15 years.

O-horizon: freshly-fallen & partially-decomposed leaves, twigs, animal waste, fungi & organic materials. Colour: brown or black. A-horizon: humus/partially decomposed organic matter & some inorganic mineral particles. darker & looser than the deeper layers. O & A-horizon: contain a large amount of bacteria, fungi, earthworms, small insects, forms complex food web in soil, recycles soil nutrients, & contribute to soil fertility. B-horizon /(subsoil): less organic material & fewer organisms than A- horizon. C-horizon: consists of broken-up bedrock, does not contain any organic materials. Chemical composition helps to determine pH of soil & also influences soil’s rate of water absorption & retention. R-horizon: The unweathered rock (bedrock) layer that is beneath all the other layers

Soil Pollution Soil pollution is caused by the presence of chemicals or other alteration in the natural soil environment. Resulting in a change of the soil quality likely to affect the normal use of the soil or endangering public health and the living environment. 4

CAUSES OF SOIL DEGRADATION Soil erosion/degradation is the loss of top soil erodes fertility of soil & reduces its water-holding capacity. Excessive farming, construction, overgrazing, burning of grass cover and deforestation Excess salts and water (Salinization) Excessive use of fertilizers & pesticides Solid waste :

First effect of pollutants Washed away: might accumulates somewhere Evaporate: can be a source of air pollution Infiltrate through the unsaturated soil to the groundwater DDT: fat soluble, stored in fatty tissues Interferes with calcium metabolism Results in thin egg shells in birds Agent orange: code name for one of the herbicides and defoliants (results in leaf fall) used by the U.S. military as part of its herbicidal warfare program, During the Vietnam War, between 1962 and 1971, the United States military sprayed 20,000,000 US gallons (80,000,000 L) of chemical herbicides and defoliants in Vietnam anti fertility, skin problems, cancer

Control of soil pollution Use of pesticides and fertilizers should be minimized. Cropping techniques should be improved to prevent growth of weeds. Special pits should be selected for dumping wastes. Controlled grazing and forest management. Wind breaks and wind shield in areas exposed to wind erosion Afforestation and reforestation. 3 Rs: reduce, reuse, recycle 7

Information needed to clean up materials added to soil Kind of material-organic or inorganic- is the material biodegradable/ dangerous to animals & humans How much material was added to the soil, will it overload the organisms in the soil C:N ratio of the pollutant material Nature of soil: will the soil be able to handle the material before groundwater is contaminated Growing conditions for the soil organisms: - is it too cold, too wet etc. How long the material has been on site: is there evidence of environmental problems, is it undergoing decomposition. Immediate danger to people & environment: Urgency of the situation.

Bioremediation The use of naturally occuring microorganisms such as bacteria, fungi & plants to break down or degrade toxic chemical compounds that have accumulated in the environment It is a method that treats the soils and renders them non-hazardous, thus eliminating any future liability that may result from landfill problems or violations.

Factors affecting bioremediation Microbial factors Temperature favorable for organisms Availability of water (Moisture content) Availability of nutrients (N,P,K) C: N (carbon: nitrogen) ratio of the contaminant material< 30:1 pH Availability of Oxygen in sufficient quantity in soil.

In situ Bioremediation : The treatment in place without excavation of contaminated soils or sediments. Ex situ bioremediation: requires pumping of the groundwater or excavation of contaminated soil prior to remediation treatments.

Types of In situ Bioremediation Biostimulation: To stimulate the activity of microorganisms by adding nutrients and electron acceptors (e.g. O2) Bioventing: Injecting air through soil to stimulate microbe growth in unsaturated zone Biosparging: Injection of air/nutrients into unsaturated and saturated zones Bioaugmentation: inoculation of soil with microbes or adding exogenous microbes to the subsurface

In-situ-Bioremediation Good for large volumes Slower Doesn’t work well in clays or highly layered subsurfaces Less expensive Creates less dust Less possibility of contaminant release into environment Biostimulation (stimulates biological activity) Bioventing (Inject air/nutrients into unsaturated zone – good for midweight petroleum, jet fuel) Biosparging (Inject air/nutrients into unsaturated and saturated zones) Bioaugmentation (inoculates soil with microbes)

Biostimulation Biosparging

Ex-situ -Bioremediation Easier to control Used to treat wider range of contaminants and soil types Costly Faster Slurry-phase-Soil combined with water/additives in tank, microorganisms, nutrients, oxygen added Solid-phase Land-farming: soil put on pad, leachate collected Soil biopiles: soil heaped, air added Composting: biodegradable waste mixed with bulking agent Land Applied –waste added directly to soil which is later planted to a crop.

Advantages of Using Bioremediation Processes Compared With Other Remediation Technologies biologically-based remediation detoxifies hazardous substances instead of merely transferring contaminants from on environmental medium to another; (2) bioremediation is generally less disruptive to the environment than excavation-based processes; and (3) The cost of treating a hazardous waste site using bioremediation technologies can be considerably lower than that for conventional treatment methods: vacuuming, absorbing, burning, dispersing, or moving the material .

Marine pollution The introduction by man, directly, or indirectly, of substances or energy to the marine environment resulting in deleterious effects such as: hazards to human health, hindrance to marine activities, impairment of the quality of seawater for various uses and reduction of amenities. Does not include natural processes like volcanic eruptions or earthquakes

Marine pollutants Agricultural run offs ((herbicides, pesticides and nutrients) Sediments Sewage (Faecal Coliform and Pathogens) Chemicals, Metals and Radioactive Substances Persistent toxins (PCBs, DDT, heavy metals) Oil Plastics Energy (Thermal & light)

Sources of marine pollution Land sources 80% of non-biological marine pollution comes from land based activities pipes discharging directly into marine waters(sewage, industrial, chemical and food processing wastes) Riverine flows into the sea carry pollutants from the entire catchment area. From Air Global atmospheric inputs to the sea from air discharges Oil spills and offshore sources Oily discharges from ballast water and bilge water during routine ship operations and illegal dumping of solid waste Designated dumping grounds at sea Accidental spills from Ships carrying hazardous substances, oil, gas etc.

Control measures for oil pollution Natural process of emulsification of oil by use of chemical dispersants: can be sprayed on the oil. Slick-lickers: continuous belt of absorbent material dips through the oil slick & is passed through rollers to extract oil. Rocks can be cleaned with high pressure steam

Effects of marine pollution: Effects on sea life Effects on birds Effects on human being Health Business Eutrophication and development of red tides (phytoplankton blooms carrying red pigmentation) Development of oil slick: When oil is spilled on sea, it spreads over the surface forming a thin film called OIL SLICK. Which damage marine life

Effects of marine pollution Damages marine life to a large extent, for salt-marsh plants, oil slicks can affect flowering, fruiting and germination. Coral reefs If liquid oil contaminates a bird’s plumage, its water-repellent properties are lost, drown, die Drill cuttings dumped on seabed create anoxic conditions & result in the production of toxic sulphides in the bottom sediment thus eliminating the benthic fauna. Fish and shellfish production facilities can also be affected by oil slicks. Commercial damage is tainting: imparts an unpleasant flavor to fish and seafood & is detectable even at extremely low levels of contamination.

NOISE POLLUTION Defined as unwanted sounds that unreasonably (a kind of harsh, loud and confused sound), intruding into our daily activities The most significant attributes of noise are: Its loudness Duration The unit of noise is decibel. Human ear can tolerate noise up to 120 decibels.

Sources of NOISE POLLUTION Road Traffic: Most prevalent and most damaging source Impact of road traffic noise depends on factors like: road location & design, and land use planning measures, building design, vehicle standards & driving behavior (ii) Air Traffic Noise from supersonic crafts are dangerous because of its intensity (iii) Railways: The level of noise associated with rail traffic is related to type of engine or rolling stock used, speed of the train, track type & condition, warning signals at crossings, whistles & horns, freight classification yards, & railroad construction & maintenance. (iv) Industry Product fabrication Product assembly Power generation Processing. (v) Construction: construction equipments. (vi) Consumer products: recreational, hobbies/workshop, household, music. (vii) Other sources: sirens, agricultural noise, noise from animals, humans & military

Measurement of Noise Noise intensity is measured in decibel (Db) units Decibel scale is logarithmic, Each 10 Db increase represents a 10 fold increase in noise intensity distance diminishes the effective decibel level reaching the ear. e.g. Moderate auto traffic at a distance of 30 m rates about 50 decibels, but for the same, for a driver with a car window open or a pedestrian on the sidewalk, same traffic rates about 70 decibels.

Effects of Noise At 45 decibels of noise, average person cannot sleep, At 85 decibels hearing damage, & at 120 decibels ear experiences pain. Lack of sleep, irritability, heartburn, indigestion, ulcers, high blood pressure, & possibly heart disease Hearing loss Non-auditory physiological effects Annoyance Communication interference

Noise Pollution Control Source path receiver concept: Can be controlled either by reducing the noise at the source or by preventing its transmission or by protecting the receiver At the source: lubrication of machines, tightening the loose units, reducing the eccentricity In the path: keeping the noisy machine covered, construction of noise barriers, sound-proofing of the building Receiver: No use of horns other than in emergency, vehicle engines and appliances in good Condition, purchase the least noisy air conditioner or vacuum cleaner/quieter appliances, rest areas away from noise, turn down volume of Stereos.

Thermal Pollution Thermal pollution is the process of heating up of water bodies through run off or discharge Decreases the solubility of oxygen, resulting in suffocation of plants and animals Human activities introducing thermal pollution: Industries and power plants Trees and tall vegetation providing shades are cut down Soil erosion by construction, removal of stream side vegetation, farming practices, overgrazing & recreation increases – reduction in green Thermal pollution can also occur through Earthquakes

Effects of Thermal Pollution Thermal shock Thermal enrichment: Heated water from power plant may be used to extend plant growing season, speed up growth of fish and other aquatic animal for commercial purpose