Central district heating systems have gained attention in recent years because they can be more efficient than localized boiler units. The efficiency of district heating is usually due to power generation plants being able to produce heat and electricity simultaneously. District heating also helps prevent pollution by using advanced flue gas cleaning techniques.
The North Texas Metropolitan Water District began working to add ozone to its four interconnected water treatment facilities which operate as the Wylie Water Treatment Plant (WTP).
The Mazzei Sidestream Venturi Injection – Pipeline Flash Reactor System provides a feasible alternative for dissolution of ozone at the Clark County Water Reclamation District (CCWRD) in Las Vegas, because it allowed for flexibility in basin design to meet geographic site constraints.
A water quality audit revealed that two of the largest drinking water plants in the City of Montreal were out of compliance with Quebec’s latest water quality rules. Both drinking water facilities were located in heavily populated areas; consequently, plant modifications had to be accomplished within their existing infrastructure footprints.
A potable water plant in Eastern Angelina County, Texas, serves over 2,000 rural customers.
The design team for the intermediate ozone system at Buckingham Water Treatment Plant, Quebec, had limited space available for ozone contacting for the plant’s 1.3 – 7.4 MGD flow, so a standard fine bubble diffusion basin for ozone disinfection was not an option.
A chemical company which specializes in Clean-In-Place (CIP) systems, contacted Mazzei to discuss the use of ozone as an alternative to peracetic acid sanitation or heat sterilization at their customers’ plants.
The Santa Barbara desalination plant located in the south-eastern part of Curaçao provides drinking water to about half of the population of this Caribbean island. With an average precipitation of approximately 500 mm, rainwater is the only natural source of freshwater in the island. Government efforts to address the water shortage problem date back to the 20s of the last century. Initially based on evaporation, the seawater desalination evolved into the reverse osmosis technology in the 90s. After several years of experimenting with RO, Aqualectra, the municipal supplier of potable water and electricity for Curaçao, took the decision to move forward with this technology and in 2003 started a project to build a SWRO desalination plant.
An MABR is essentially a biological wastewater treatment process that utilizes seemingly passive aeration through oxygen-permeable membranes. Oxygen transfer through the MABR membranes is diffusion based: driven by concentration differences such that oxygen passes from air at atmospheric pressure into water at a higher hydrostatic pressure. This oxygen transfer mechanism, wherein air is supplied to the process at very low pressure, is the reason MABRs have significantly lower energy consumption compared to other wastewater treatment processes, such as conventional activated sludge (CAS), that utilize diffusers. This energy savings is one of the key reasons MABRs are gaining traction in the municipal wastewater industry.
The city of Limassol in Cyprus was experiencing an increasingly severe water shortage, with the growing population and expanding tourist industry placing extra pressure on existing supply. An aquifer in a residential neighborhood was seen as a potential water source, but had high levels of salts and nitrates. The Cyprus Water Development Department (WDD) awarded Fluence a Build-Own-Transfer (BOT) contract to implement a cost-effective solution.
After an international tender process, the Israel Electric Company (IEC) chose Fluence to design, manufacture, and supply containerized ultrapure water production systems for use as makeup water for heat-recovery steam generators (HRSG) and for NOx emission reduction at recently upgraded power plants across Israel. More than 15 units of 20 m3/h production modules, each fitted in two 40-foot shipping containers, were provided to seven power plants. Their compact design allowed for ease of installation, operation, and maintenance while meeting the customer’s demanding engineering standards.
Reverse osmosis (RO) membranes are widely used in potable water, wastewater, and industrial applications. However, a major issue in the application of RO membrane technology for desalination and wastewater reclamation is membrane fouling. It limits operating flux, decreases water production, and increases power consumption. Membrane fouling also increases the need for RO plants to perform periodical membrane CIP procedure. These problems decrease process efficiency, increase operation cost, and raise environmental issues related to the CIP solutions disposal.
Hayogev is a residential development in the rural area of Jezreel Valley, with 1000 homes, agricultural fields and dairy farms. Located in an open field next to small farms, the local treatment facility handles wastewater from HaYogev and Midrach Oz. The customer was looking for a localized wastewater treatment solution to replace the existing pond system, which faced difficulties in treating the wastewater due to high levels of nutrients. A new state-level regulation concerning reclaimed water required the wastewater treatment plant (WWTP) operator to reduce the nutrients in the effluent stream. The solution had to be odorless and quiet, have low power consumption, and use the existing pond and structure.
The 64,000 sq ft Chesapeake Bay Watershed includes parts of MD, VA, WV, PA, and NY. Of the 1,000s of WWTPs supporting nearly 18 million people in the watershed, 470 are designated by EPA as significant sources of nutrients and TSS. Algal blooms reduce DO levels in the water, killing plant and animal life — from marsh grasses to blue crabs to rockfish. Learn how De Nora TETRA Denite technology is treating 450+ MGD in the Bay.
Water membranes are widely used in the water treatment processes. They have become a fundamental player in separation technology because of the fact that they require no additional chemicals and their relatively low energy requirements.
Water membranes have been applied during the extraction of produced water, treatment of waste/sewage water and processing of surface water all with huge success levels. Conventional water treatment techniques are over time incorporating in their processes the use on water membranes. Commercialization of membranes was first done in the 1970s and 1980s.
Membrane technology is chiefly based on the presence of pores on the membranes that make them semi-permeable. The simple principle on which water membranes work is such that the semi-permeability of water membranes ensures that only water is allowed to pass through a specific membrane while trapping unwanted particles and substances.
In both microfiltration and ultra filtration, membranes provide an effective barrier for arresting suspended solids in water.
To aid substances to penetrate across a semi-permeable membrane the following steps are undertaken: Electric potential introduction, high pressure application and ensuring that the concentration gradient on both sides of the membrane is maintained. The surface area of the membrane also determines the efficiency of the membrane in use.
The only drawback on water membranes is that they cannot remove substances that are actually dissolved in the water such as phosphorus, nitrates and heavy metal ions. The following are categories of membranes: Microfiltration (MF), Ultra filtration (UF), Reverse osmosis (RO), and Nanofiltration (NF) membranes
Ultra filtration membranes employ polymer technology with chemically created microscopic pores that trap dissolved substances therefore eliminating the possible use of any coagulants.