By Laura Martin
Behind on what's hot in the wastewater industry? Get up-to-date with this list of Water Online articles on the industry trends and challenges that everyone is talking about. Read on and you'll be sure to impress your colleagues.
1) Energy Production And Conservation
Finding the ideal balance between energy and water consumption has always been a challenge. Energy use at a water or wastewater utility can be 30 percent to 50 percent of the municipality’s total electricity consumption. In addition, the energy industry itself requires a significant amount of water to operate. But a water-energy nexus solution is on the horizon, as more energy-efficient technologies and alternative energy production methods are developed.
Stories On Energy From Water Online:
Can Co-Locating Utilities Solve The Water-Energy Nexus?
5 Reasons To Harvest The Power Of Biogas
2) Nutrient Management
Changing regulations and increasingly stringent effluent limits have brought nutrient management to the forefront of the wastewater industry.
Stories On Nutrient Management From Water Online
'Peecycle' Please: Will Urine Separation For Nutrient Recovery Take Off?
3 Alternative Nutrient-Removal Techniques
What Everyone Should Know About Enhanced Biological Phosphorus Removal
3) Residuals and Biosolids
The management and removal of residuals, sludge, and biosolids, has historically been a burden on wastewater utilities, accounting for nearly 50 percent of treatment costs. But this “waste” may hold the key to additional revenue if reclaimed and sold.
Stories On Residuals and Biosolids From Water Online:
Revolutionary Sludge Management Comes To America
Bio-Dredging: Cost-Saving Sludge Digestion For Lagoons
4) Water Reclamation And Reuse
There is a growing trend of reusing treated wastewater effluent for both drinking water and industrial applications. On the drinking water side, water shortages have made direct potable reuse (DPR) and indirect potable reuse applications a necessity in parts of the country. Pressure to use less water on the industrial sector has resulted in innovative reuse applications as well.
Stories On Water Reuse From Water Online:
Texas Leads The Way With First Direct Potable Reuse Facilities In U.S.
Fit-for-Purpose Water Reuse And The Road Toward Water Security
New Indirect Potable Reuse Regulations — What To Expect
5) Water Supply And Water Management
In water-scarce areas, managing water supply can be challenging. First, it can be difficult to even determine how much water is available, via groundwater, surface water, reuse, and other sources. Then, there is the challenge of figuring out how water should be allocated between consumers and industrial applications, and how much needs to remain untouched for the sake of the environment. If there isn’t enough to go around, conservation techniques or usage restrictions may have to be considered.
Stories On Water Supply And Management From Water Online:
Tackling The Drought: The Relationship Between Water Law And Water Budget
Why Engineers Can't Solve The Water Shortage With Supply-Side Solutions
6) Stormwater, Green Infrastructure, And Wet Weather Management
Stormwater management is a growing focus for the wastewater industry. Heavy wet-weather events often overwhelm wastewater systems — which are often too small for a growing population — and untreated sewage ends up overflowing into local water bodies. Green infrastructure solutions and growing regulation offer solutions.
Stories On Stormwater From Water Online:
EPA Stormwater Ruling: How Will It Impact Utilities?
Save The Rain: Preventing Combined Sewer Overflows
7) ‘Flushable’ Wipes And Collection Systems
Recently, collection systems have been in the spotlight. The increased attention is thanks (or no thanks) to “flushables,” non-dispersible cleansing cloths that are wreaking havoc on headworks all over the country.
Stories On “Flushables” From Water Online:
Nondispersibles' Turning Sewers Into Nightmares Nationwide
Looming In The Sewers: Nonwovens Are Weaving A Tangled Web
8) Industrial Wastewater
Oil and gas, agriculture, pharmaceuticals, mining, food and beverage processing—the list of industries with growing wastewater challenges goes on and on. Water Online has reported on the modeling, design, and operation of industrial wastewater treatment systems, anaerobic and biological industrial treatment processes, regulatory impacts, and more.
Stories On Industrial Wastewater From Water Online:
The Importance Of An Industrial Water Treatment Program
Has Fracking Gone ‘Green'?
9) Utility Management
Utility executives and managers have a wide range of challenges to overcome. Their workforce is aging and their budgets are shrinking. Public outreach is more important than ever before, and regulations and government oversight are increasing.
Stories On Utility Management From Water Online
New Standard Applies To Every Water Manager, Everywhere
How To Deliver Better Water And Increase Consumer Confidence Simultaneously
10) Innovative Technology
Change is needed in the wastewater industry. Cutting-edge products and services focused on everything from resource recovery and big data management, to innovative green infrastructure solutions are coming to the forefront.
Stories On Innovation From Water Online:
The Top 12 Water Technology Hotspots In America
Ontario's Water Tech Acceleration Project: Fighting For The Future Of Water
Image credit: "Fulton Officials Discuss Improvements to Wastewater Treatment Plant," KOMUnews © 2014, used under an Attribution-ShareAlike 2.0 Generic license: https://creativecommons.org/licenses/by-sa/2.0/
Wastewater (or waste water) is any type of water that has been affected by human use. Wastewater is "used water from any combination of domestic, industrial, commercial or agricultural activities, surface runoff or stormwater, and any sewer inflow or sewer infiltration". Therefore, wastewater is a byproduct of domestic, industrial, commercial or agricultural activities. The characteristics of wastewater vary depending on the source: domestic wastewater from households, municipal wastewater from communities (also called sewage) or industrial wastewater from industrial activities. Wastewater can contain physical, chemical and biological pollutants.
Households may produce wastewater from flush toilets, sinks, dishwashers, washing machines, bathtubs and showers. Dry toilets produce less wastewater than those that use flush toilets.
Wastewater may be conveyed in a sanitary sewer which conveys only sewage. Alternatively, it can be transported in a combined sewer which includes stormwater runoff and industrial wastewater. After treatment at a wastewater treatment plant, the treated wastewater (also called "effluent") is discharged to a receiving water body. The terms "wastewater reuse" or "water reclamation" apply if the treated waste is used for another purpose. Wastewater that is discharged to the environment without suitable treatment causes water pollution.
In developing countries and in rural areas with low population densities, wastewater is often treated by various on-site sanitation systems and not conveyed in sewers. These systems include septic tanks connected to drain fields, on-site sewage systems (OSS), vermifilter systems and many more.
The overarching term sanitation includes the management of wastewater, human excreta, solid waste and stormwater. The term sewerage refers to the physical infrastructure required to transport and treat wastewater.
Sources of wastewater include the following domestic or household activities:
- Human excreta (feces and urine) often mixed with used toilet paper or wipes; this is known as blackwater if it is collected with flush toilets;
- Washing water (personal, clothes, floors, dishes, cars, etc.), also known as greywater or sullage;
- Surplus manufactured liquids from domestic sources (drinks, cooking oil, pesticides, lubricating oil, paint, cleaning liquids, etc.).
Activities producing industrial wastewater:
- Industrial site drainage (silt, sand, alkali, oil, chemical residues);
- Industrial cooling waters (biocides, heat, slimes, silt);
- Industrial processing waters;
- Organic or biodegradable waste, including waste from hospitals, abattoirs, creameries, and food factories;
- Organic or non bio-degradable waste that is difficult-to-treat from pharmaceutical or pesticide manufacturing;
- Extreme pH waste from acid and alkali manufacturing;
- Toxic waste from metal plating, cyanide production, pesticide manufacturing, etc.;
- Solids and emulsions from paper mills, factories producing lubricants or hydraulic oils, foodstuffs, etc.;
- Water used in hydraulic fracturing;
- Produced water from oil & natural gas production.
Other activities or events:
- Urban runoff from highways, roads, carparks, roofs, sidewalks/pavements (contains oils, animal feces, litter, gasoline/petrol, diesel or rubber residues from tires, soapscum, metals from vehicle exhausts, de-icing agents, herbicides and pesticides from gardens,etc.);
- Agricultural pollution, direct and diffuse.
Wastewater can be diluted or mixed with other types of water by the following mechanisms:
The composition of wastewater varies widely. This is a partial list of pollutants that may be contained in wastewater:
Chemical or physical pollutants
- Heavy metals, including mercury, lead, and chromium;
- Organic particles such as feces, hairs, food, vomit, paper fibers, plant material, humus, etc.;
- Soluble organic material such as urea, fruit sugars, soluble proteins, drugs, pharmaceuticals, etc.;
- Inorganic particles such as sand, grit, metal particles, ceramics, etc.;
- Soluble inorganic material such as ammonia, road-salt, sea-salt, cyanide, hydrogen sulfide, thiocyanates, thiosulfates, etc.;
- Macro-solids such as sanitary napkins, nappies/diapers, condoms, needles, children's toys, dead animals or plants, etc.;
- Gases such as hydrogen sulfide, carbon dioxide, methane, etc.;
- Emulsions such as paints, adhesives, mayonnaise, hair colorants, emulsified oils, etc.;
- Toxins such as pesticides, poisons, herbicides, etc.;
- Pharmaceuticals and hormones and other hazardous substances;
- Thermal pollution from power stations and industrial manufacturers;
Sewage cointaining human feces may also contain pathogens of one of the four types:
- Bacteria (for example Salmonella, Shigella, Campylobacter, Vibrio cholerae);
- Viruses (for example hepatitis A, rotavirus, enteroviruses);
- Protozoa (for example Entamoeba histolytica, Giardia lamblia, Cryptosporidium parvum) and
- Parasites such as helminths and their eggs (e.g. Ascaris (roundworm), Ancylostoma (hookworm), Trichuris (whipworm)).
It can also contain non-pathogenic bacteria and animals such as insects, arthropods, small fish.
Main article: Wastewater quality indicators
Since all natural waterways contain bacteria and nutrients, almost any waste compounds introduced into such waterways will initiate biochemical reactions (such as shown above) measured in the laboratory as the biochemical oxygen demand (or BOD). Such chemicals are also liable to be broken down using strong oxidizing agents and these chemical reactions create what is measured in the laboratory as the chemical oxygen demand (COD). Both the BOD and COD tests are a measure of the relative oxygen-depletion effect of a waste contaminant and they have been widely adopted as a measure of pollution effect. The BOD test measures the oxygen demand of biodegradable pollutants whereas the COD test measures the oxygen demand of oxidizable pollutants.
Any oxidizable material present in an aerobic natural waterway or in an industrial wastewater will be oxidized both by biochemical (bacterial) or chemical processes. The result is that the oxygen content of the water will be decreased.
Main article: Wastewater treatment
At a global level, around 80% of wastewater produced is discharged into the environment untreated, causing widespread water pollution.:2
There are numerous processes that can be used to clean up wastewaters depending on the type and extent of contamination. Wastewater can be treated in wastewater treatment plants which include physical, chemical and biological treatment processes. Municipal wastewater is treated in sewage treatment plants (which may also be referred to as wastewater treatment plants). Agricultural wastewater may be treated in agricultural wastewater treatment processes, whereas industrial wastewater is treated in industrial wastewater treatment processes.
For municipal wastewater the use of septic tanks and other On-Site Sewage Facilities (OSSF) is widespread in some rural areas, for example serving up to 20 percent of the homes in the U.S.
One of the most used methods of aerobic treatment system is the activated sludge process, based on the maintenance and recirculation of a complex biomass composed of micro-organisms able to absorb and adsorb the organic matter carried in the wastewater. Anaerobic wastewater treatment processes (UASB, EGSB) are also widely applied in the treatment of industrial wastewaters and biological sludge. Some wastewater may be highly treated and reused as reclaimed water. Constructed wetlands are also being used.
In some urban areas, municipal wastewater is carried separately in sanitary sewers and runoff from streets is carried in storm drains. Access to either of these systems is typically through a manhole.
During high precipitation periods, a combined sewer system may experience a combined sewer overflow event, which forces untreated sewage to flow directly to receiving waters. This can pose a serious threat to public health and the surrounding environment.
Sewage may drain directly into major watersheds with minimal or no treatment but this usually has serious impacts on the quality of an environment and on the health of people. On one hand, pathogens can cause a variety of illnesses. On the other hand, some chemicals pose risks even at very low concentrations and can remain a threat for long periods of time because of bioaccumulation in animal or human tissue.
Wastewater from industrial activities may be pumped underground through an injection well. Wastewater injection has been linked to Induced seismicity.
Main article: Reclaimed water
Treated wastewater can be reused in industry (for example in cooling towers), in artificial recharge of aquifers, in agriculture and in the rehabilitation of natural ecosystems (for example in wetlands). In rarer cases, it is also used to augment drinking water supplies. There are several technologies used to treat wastewater for reuse. A combination of these technologies can meet strict treatment standards and make sure that the processed water is hygienically safe (free from bacteria and viruses). The following are some of the typical technologies: Ozonation, ultrafiltration, aerobic treatment (membrane bioreactor), forward osmosis, reverse osmosis, advanced oxidation.
Some water demanding activities do not require high-grade water. In this case, wastewater can be reused with little or no treatment. One example of this scenario is in the domestic environment where toilets can be flushed using greywater from baths and showers with little or no treatment.
Irrigation with recycled wastewater can also serve to fertilize plants if it contains nutrients, such as nitrogen, phosphorus and potassium. In developing countries, agriculture is using untreated wastewater for irrigation. However, there can be significant health hazards related to using untreated wastewater in agriculture. The World Health Organization developed guidelines for safe use of wastewater in 2006.
Further information: Reclaimed water § Guidelines and regulations
As part of the Environmental Protection Act 1994, the Environmental Protection (Water) Policy 2009 is responsible for the water management of Queensland, Australia.
In Nigeria, the Water Resources Act of 1993 is the law responsible for all kinds of water management.
In the Philippines, Republic Act 9275, otherwise known as the Philippine Clean Water Act of 2004, is the governing law on wastewater management. It states that it is the country's policy to protect, preserve and revive the quality of its fresh, brackish and marine waters, for which wastewater management plays a particular role.
The Clean Water Act is the primary federal law in the United States governing water pollution in surface waters.Groundwater protection provisions are included in the Safe Drinking Water Act, Resource Conservation and Recovery Act, and the Superfund act.
|Wikimedia Commons has media related to Wastewater.|
- ^Tilley, E., Ulrich, L., Lüthi, C., Reymond, Ph., Zurbrügg, C. Compendium of Sanitation Systems and Technologies – (2nd Revised Edition). Swiss Federal Institute of Aquatic Science and Technology (Eawag), Duebendorf, Switzerland. p. 175. ISBN 978-3-906484-57-0.
- ^World Health Organization (2006). Guidelines for the safe use of wastewater, excreta, and greywater. World Health Organization. p. 31. ISBN 9241546859. OCLC 71253096.
- ^Andersson, K., Rosemarin, A., Lamizana, B., Kvarnström, E., McConville, J., Seidu, R., Dickin, S. and Trimmer, C. (2016). Sanitation, Wastewater Management and Sustainability: from Waste Disposal to Resource Recovery. Nairobi and Stockholm: United Nations Environment Programme and Stockholm Environment Institute. ISBN 978-92-807-3488-1, p. 56
- ^WWAP (United Nations World Water Assessment Programme) (2017). The United Nations World Water Development Report 2017. Wastewater: The Untapped Resource. Paris. ISBN 978-92-3-100201-4. Archived from the original on 8 April 2017.
- ^U.S. Environmental Protection Agency, Washington, D.C. (2008). "Septic Systems Fact Sheet." EPA publication no. 832-F-08-057.
- ^van der Baan, Mirko; Calixto, Frank J. (2017-07-01). "Human-induced seismicity and large-scale hydrocarbon production in the USA and Canada". Geochemistry, Geophysics, Geosystems. 18 (7): 2467–2485. doi:10.1002/2017gc006915. ISSN 1525-2027.
- ^WHO (2006). WHO Guidelines for the Safe Use of Wastewater, Excreta and Greywater – Volume IV: Excreta and greywater use in agriculture. World Health Organization (WHO), Geneva, Switzerland
- ^"Environmental policy and legislation". Department of Environmental and Heritage Protection. Queensland Government. Retrieved October 20, 2017.
- ^ ab"An Act Providing For A Comprehensive Water Quality Management And For Other Purposes". The LawPhil Project. Retrieved September 30, 2016.
- ^United States. Clean Water Act.33 U.S.C. § 1251et seq.Pub.L. 92-500, 18 October 1972; as amended.