water treatment "how does water temperature influence the volume of sludge produced?"

How can the volume of sludge be reduced?

There are essentially two methods by which the volume of sludge is reduced: consolidation, which reduces the sludge volume by removing the water along with the associated dissolved solids, and destruction, in which the organic carbon component of the sludge is either oxidised, ultimately to carbon dioxide, or reduced, predominantly to methane.

What are the principal sludge streams in wastewater treatment?

For conventional municipal wastewater treatment, the two principal sludge streams are: the secondary biological treatment stage, producing waste activated sludge (WAS) if the biological treatment is based on the activated sludge process [links to The MBR Site].

What is sludge conditioning and how does it remove water?

Water removal is made easier by modifying the sludge through chemical or thermal treatment. These treatment processes are referred to as sludge conditioning, and act by changing the size and/or other characteristics of the sludge suspended solids. Sludge process types Credit: Judd Water & Wastewater Consultants

What is water treatment sludge (WTS) in water treatment plant?

All water treatment plants (WTPs) produce waste/residue known as water treatment sludge (WTS) during the purification of raw water. The sludge produced a WTP at Ghaziabad, India is investigated for physical and chemical characteristics. It consist of about 60% fine sand in grain size range 150-75μ.

How does temperature affect wastewater treatment?

Cold wastewater As temperature decreases, so does microbial activity. The biological and chemical reduction of organic material proceeds very slowly under low temperatures. It has been found that microbes used in wastewater treatment become dormant from 35 to 39 degrees F.

What is the importance of controlling the temperature of the wastewater effluent?

In most cases, the bacteria used in water treatment plants function optimally at temperatures between 68°F and 95°F. These microorganisms can still function at a slowed rate with lower temperatures, but significant elevations in thermal conditions can destroy the bacteria and render the process ineffective.

What are the 3 stages of wastewater treatment PDF?

Wastewater is treated in 3 phases: primary (solid removal), secondary (bacterial decomposition), and tertiary (extra filtration).

How does temperature affect activated sludge?

Specific resistance to filtration of sludge, sludge production rate and phosphate removal decrease with an increase in temperature from 10 C to 30 C. The sludges· possess better resistance to bulking at higher temperatures and at low loadings.

What is temperature in sludge processing?

The maximum acceptable operating temperature for typical activated sludge systems is limited to about 35° to 40°C [95 to 104°F], which corresponds to the maximum temperature for the growth of mesophilic organisms.

Why treatment of water is required explain the different stages of water treatment?

Water treatment is the process of removing all those substances, whether biological, chemical, or physical, that are potentially harmful to the water supply for human and domestic use. This treatment helps to produce water that is safe, palatable, clear, colorless, and odorless.

What are the three main purposes of water treatment?

Water treatment is a process involving different types of operations (physical, chemical, physicochemical and biological), the aim of which is to eliminate and/or reduce contamination or non-desirable characteristics of water.

How does water treatment work?

These filters remove dissolved particles and germs, such as dust, chemicals, parasites, bacteria, and viruses. Activated carbon filters also remove any bad odors. Water treatment plants can use a process called ultrafiltration in addition to or instead of traditional filtration.

What is surface water treatment?

Surface water Treatment for potable supplies typically involves coagulation, flocculation, Sedimentation, and filtration processes for removing colloidal as well as suspended solids from raw water. All water treatment plants (WTPs) produce waste/residue known as water treatment sludge (WTS) during the purification of raw water. The sludge produced a WTP at Ghaziabad, India is investigated for physical and chemical characteristics. It consist of about 60% fine sand in grain size range 150-75μ. Silica, alumina, ferric oxide and lime constitute the major percentage of chemical components present in the sludge. Some heavy metals are also found in the sludge. Discharging WTS into river, streams, ponds, lakes, drains etc. or landfilling the dewatered WTS is not environment friendly disposal option. Based on the characteristics, sustainable and profitable disposal through recycling and reuse have been reviewed. Utilization of WTS in brick making, in ceramics making, in the manufacture of cement and cementitious materials and as a substitute to building materials could provide safe disposal route. Reuse in wastewater treatment, in removal of heavy metals from aqueous solutions and in nutrient reduction from laden soils and runoffs are also some of the possible alternatives. It is required to explore suitable option for developing sustainable sludge management strategies under stringent environmental norms.

Where is sludge discharged?

In general, this sludge is discharged directly into nearby hydric bodies or dumped in the landfills after dewatering. The simple method of final disposal, although less expensive, is not a proper solution due to the possibility of contamination of water bodies and soil from the chemical products used in the treatment.

Is WTS waste disposal environmentally friendly?

Some heavy metals are also found in the sludge. Discharging WTS into river, streams, ponds, lakes, drains etc. or landfilling the dewatered WTS is not environment friendly disposal option. Based on the characteristics, sustainable and profitable disposal through recycling and reuse have been reviewed.

Is sludge management a challenge?

Therefore, development of sustainable sludge management strategies under stringent environmental norms is a challenging task for environmental scientists and engineers.

How does a water treatment unit work?

Even though EPA regulates and sets standards for public drinking water, many Americans use a home water treatment unit to: 1 Remove specific contaminants 2 Take extra precautions because a household member has a compromised immune system 3 Improve the taste of drinking water

What is the process of boiled water?

Distillation is a process in which impure water is boiled and the steam is collected and condensed in a separate container, leaving many of the solid contaminants behind. Disinfection. Disinfection is a physical or chemical process in which pathogenic microorganisms are deactivated or killed.

What are the steps of water treatment?

Today, the most common steps in water treatment used by community water systems (mainly surface water treatment) include: Coagulation and flocculation are often the first steps in water treatment. Chemicals with a positive charge are added to the water.

What is a CCR report?

Every community water supplier must provide an annual report, sometimes called a Consumer Confidence Report, or “CCR,” to its customers. The report provides information on your local drinking water quality, including the water’s source, contaminants found in the water, and how consumers can get involved in protecting drinking water.

What is a water softener?

Water Softeners. A water softener is a device that reduces the hardness of the water. A water softener typically uses sodium or potassium ions to replace calcium and magnesium ions, the ions that create “hardness.”. Distillation Systems.

What is the most common type of water treatment system?

The most common types of household water treatment systems consist of: Filtration Systems. A water filter is a device which removes impurities from water by means of a physical barrier, chemical, and/or biological process. Water Softeners. A water softener is a device that reduces the hardness of the water.

Why is chlorine added to water?

After the water has been filtered, a disinfectant (for example, chlorine, chloramine) may be added in order to kill any remaining parasites, bacteria, and viruses, and to protect the water from germs when it is piped to homes and businesses.

What are the consequences of poor sludge management?

Poorly designed sludge treatment and management systems can lead to undesirable consequences, such as plant shutdowns, financial loss, penalties and operational problems. Familiarity with the basic sludge management and treatment components outlined here will help operators ensure these systems are not overlooked. WT

What is the seal on a pump fluid chamber?

Sealing of the pump fluid chamber is usually achieved by flexible trunnions. In other words, the sludge chamber is usually sealed with flexible trunnions, which eliminates packings, mechanical seals and requires no flushing water or other forms of flushing/lubrication.

What is double disc pump?

A double disc pump is a positive displacement pump that uses a trunnion (elastomer), a disc and a connecting rod to force sludge from the suction side to the discharge side of the pump by creating a vacuum inside the pump body. The suction and discharge valve chambers (with the check valves) help to manage higher-than-normal concentrations of grit and solids in pumped sludge.

What is a positive displacement pump?

Positive displacement pumps have been used in sludge and dense liquid services. Some positive displacement pumps have presented poor performance and low reliability. Therefore, special care is needed to select the proper positive displacement pumps for sludge services.

What is dewatering equipment?

Dewatering equipment is needed to reduce the volume of liquid in produced sludge. Sludge dewatering can be carried out by different systems such as a filter press, decanter centrifuge and others. Most often a filter press system is used, although other options for dewatering are available.

How many sludge pumps should be in a plant tank?

Ideally, each tank should be provided with a minimum of two sludge pumps (one operating and one standby), which can be used for circulating and mixing of contents. Usually, if a plant produces different sludges — such as primary sludge and secondary sludge — they are combined and treated together.

What is the first stage of sludge collection?

The first stage after the collection of sludge is usually a sludge holding tank system, which will feed the sludge to the next stage of treatment . A sludge tank system is typically used for thickening and sludge flow equalization. There should be sludge holding tank recirculation pumps and sludge transfer pumps.

How does membrane work in water treatment?

For dissolved constituents, their removal depends on the reaction kinetics. As the hydrolysis of metal–salt coagulants and formation of metal hydroxide are generally rapid under typical conditions in water treatment, the adsorption of organic matter on metal hydroxide floc is likely to be the controlling process in NOM removal ( Dempsey, 1989; Bottero and Bersillon, 1989 ), which is in turn governed by both coagulation chemistry and hydrodynamic conditions. An example of DOC removal as a function of flocculation time is illustrated in Figure 10 ( Leiknes et al., 2004 ). The flocculation time varied from 0.75 to 20 min, which covers the time frame of rapid mixing and flocculation in a typical water treatment plant. In this example, DOC removal efficiency varies approximately 5% – a measurable but small change. This data suggests that the difference in TOC reduction by different coagulation processes is likely insignificant. It should be noted that other treatment objectives other than DOC and turbidity removal can also dictate the selection of the coagulation process. For example, in a pilot test with MF, direct coagulation was unable to meet the requirement for manganese oxidation ( Gallagher et al., 2005 ).

What are the most important problems in water?

If the water originates from a surface water supply such as a river, lake, or dam, then the suspended particles are the most important problem. Different techniques to remove suspended particles include the addition of coagulants and the use of membranes.

What is membrane technology?

The development of large-scale modules with lower-energy consumption reduced costs significantly. Especially in the water industry, membrane technology has grown much more than coagulation and ozonation, since membranes require minimal addition of aggressive chemical reagents and produce no by-products.

Why is membrane technology important?

Membrane technology is useful for recovering clean water from polluted water. Recent technological advances, such as the development of more selective and permeable membranes, increased membrane lifetimes, reduced fouling and cleaning cycles. The development of large-scale modules with lower-energy consumption reduced costs significantly. Especially in the water industry, membrane technology has grown much more than coagulation and ozonation, since membranes require minimal addition of aggressive chemical reagents and produce no by-products. At present, many membrane-based water reclamation facilities operate worldwide, their number and capacity growing steadily (Ashkelon sea water desalination plant installed in 2004 in Israel with a capacity of 275.000 m 3 d −1 ).

How much does a POE treatment system cost?

Consider cost: Cost for treatment systems can vary tremendously. Pitcher type systems can be as little as $30, whereas multistage POE systems can be of several thousand dollars.

What will the future of brewing water systems be like?

Brewery water treatment systems of the future will be very flexible, allowing breweries to tailor-make their water for different products. At the same time, these future water treatment systems will aim to achieve optimum efficiency in terms of operating cost and especially wastewater produced. The advances in analysis techniques will inevitably lead to further challenges, as it will be possible to detect certain components that are not an issue today but will then need to be removed. It will also continue to be vital for brewers to pay attention to their water supply to avoid surprising and unexpected quality defects in the finished product.

How to improve the taste of water?

1. Understand the treatment need: For many consumers, simply improving the taste of the water is their primary treatment need. For some, there may be health contaminants that must be treated. And others may have very hard water, causing issues with lime scale around fixtures and possibly damaging appliances. 2.

How much water treatment sludge is produced annually?

It is estimated that over 100,000 tons of water treatment sludge produced every year as the waste of conventional potable water treatment. This quantity is predicted to continually rise to cope with the increasing potable water demand as a result of population growth and urbanization, making the proper management and disposal of residual sludge more imperative than ever (Babatunde and Zhao, 2007).To address this issue, Ahmand presented a comprehensive review on a great range of papers to demonstrate various approaches and strategies for sustainable reuse of WTS through what is called 3R concept, namely recovery, recycling and reuse. And hence, hopefully, to provide multiple ways to maximise the value of sludge while minimising its negative impacts on the environment (Ahmad,2016).

How does WTS affect soil?

(Ahmand,2016) However, it is found that WTS amended soil can reduce plant-available P concentrations, and hence, decrease the amount of phosphorus available for off-site transport , which will eventually reduce P pollution and alleviate eutrophication in the receiving water body. Although there are concerns over the potential increase in Al concentration in soil when sludge is added, it is reported no notable elevated level on Al, probably because Al is mainly exist as insoluble Al (OH)3 in the soil. (Gallimore,1999)

What is WTS cement?

Cement produced using WTS as a substitution of traditional raw materials such as limestone, sand and clay, is found to have even higher compressive strength with similar hydration process and identification behaviour during the curing process. It’s notable that the overall strength is quite sensitive to the percentage of sludge that is mixed in and 28 days strength reaches the maximum at 5.5% and start to decrease afterwards. However, it is reported that contaminants such as phosphorus or sulphate may cause the change in properties of produced cement and could potentially alter the settling time.

What is WTS in wetlands?

WTS can also be used as a replacement of traditional soils and gravels as substrates of constructed wetlands. Constructed wetlands are widely used, cost and energy efficient technique nowadays to naturally remove pollutants by infiltration mechanism. There is one drawback of CWs which is the low removal efficiency of nutrients such as nitrogen and phosphorus. Thus, environmental engineers used WTS, especially alum sludge as the wetland media and found a significant increase in P and N removal. However, one problem with this strategy is that although Al-based sludge presents great capacity to get rid of organic matter, ammoniacal nitrogen, its ability to remove overall TN (total nitrogen) is not as satisfying, which might be due to the lack of denitrification caused by limited influent carbon source.

Why are coagulants added to water?

During the flocculation unit of the water treatment process, coagulants are added into the raw water to promote the aggregation and settlement of dispersed and colloidal particles , making it a considerable contributor of the sludge.

Why is lime used as a buffer?

It is found that using lime soften sludge as a pH buffer for soil neutralization shows even higher effectiveness comparing to the conventionally used limestone. Also, the physicochemical properties of most of the sludge are found typically adequate for plant growth and hence could be a good source of topsoil during disturbed sites reclamation process.

Why is organic matter increasing in surface water?

For organic matter, the result showed an increase in natural organic matter in surface water due to the climate change happened for the last 30 years. It may oppress water treatment works and result in high coagulant and organic matter content in WTR.

Overview of Sludge Processing

Sludge Processing Methods

• There are essentially two methods by which the volume of sludge is reduced: 1. consolidation, which reduces the sludge volume by removing the water along with the associated dissolved solids, and 2. destruction, in which the organic carbon component of the sludge is either oxidised, ultimately to carbon dioxide, or reduced, predominantly to methane...

See more on sludgeprocessing.com

Sludge as A Resource