Zero Liquid Discharge Water Treatment

Zero Liquid Discharge Wastewater Treatment

Zero-liquid discharge (ZLD) is a water treatment process in which all waste water is purified and recycled; therefore, leaving zero discharge at the end of the treatment cycle. ZLD is an advanced wastewater treatment method that includes ultrafiltration, reverse osmosis, evaporation/crystallization, and fractional electro deionization.

Applications of ZLD:

  • Plant Discharge Compliance
  • Cooling Tower Blowdown
  • Flue Gas Desulphurization (FGD)
  • Gasification Wastewater
  • Coal to Chemicals (CTX) waste
  • IGCC Plant treatment

ZLD Technologies:

  • Falling Film Brine Concentrators
  • Forced Circulation Crystallizer
  • Horizontal Spray Film Evaporator
  • Hybrid Systems with Membrane Pre-Concentrators
  • Biological Treatment
  • Solids Waste Handling

Different ZLD systems:

For over 30 years vapor compression evaporation has been the most useful technology to achieve zero liquid discharge. Evaporation recovers about 95 % of a wastewater as distillate for reuse. Waste brine can then be reduced to solids in a crystallizer/dewatering device. However, evaporation alone can be an expensive option when flow rates are considerable.

One way to solve this problem is to integrate membrane processes with evaporation. These technologies are nowadays often combined to provide complete ZLD-systems. The most common membrane processes used so far are reverse osmosis (RO) and electrodialysis reversal (EDR). By combining these technologies with evaporation and crystallization ZLD systems have become less expensive. They are however combined differently depending on the circumstances. Together with these components, a variety of other well-known water treatment technologies are used in ZLD-systems for pre-treatment and polishing treatment. These treatments are:

  • pH adjustment
  • degasifier
  • mixed/separate bed
  • oil/water separator
  • neutralization
  • oxidation (UV, ozone, sodium hypochlorite) 4
  • dissolved air flotation (DAF)
  • carbon adsorption
  • anaerobic or aerobic digestion

The variation of ZLD-systems are endless

Designing a ZLD System:

Characterizing the waste stream is difficult yet essential when designing a ZLD-system. It is important to start off with a realistic estimate of composition, feed chemistry and flow rate. A poorly described waste stream will likely lead to a design which is far from its optimum.

The system will either be too large and expensive or too small to achieve the required separation. The selection of the waste water flow rate typically determines the size and therefore the initial capital cost of the ZLD-system.

But how does one characterize a waste stream? For existing plants, waste stream compositions can be measured directly, preferably on multiple occasions to characterize a range of compositions.

Depending on the process, the feed chemistry may change occasionally, and it is of great importance that one has this in consideration. The most common measurements today include organics, for example, chemical oxygen demand (COD), biochemical oxygen demand (BOD), total organic carbon (TOC) and inorganics (anions, cations, silica).

General Guidelines:

If the water flow rate is small, not many components are necessary. The following general guidelines are accepted today:

  • Below 10 gpm of feed – crystallizers and/or spray dyers can be combined.
  • 10 – 50 gpm of feed – use a crystallizer alone.
  • 50 – 100 gpm of unsaturated feed – use an RO/EDR/crystallizer combination.
  • 50 – 100 gpm of saturated feed – use an evaporator/crystallizer combination.
  • 100 – 500 gpm of feed – either an RO/crystallizer or an evaporator/crystallizer combination may be the most economical.
  • 500 – 1000 gpm of feed – all three should be used.

Zero liquid discharge technologies help plants meet discharge and water reuse requirements, enabling your business to:

  • Meet stringent cooling tower blowdown and flue gas desulfurization (FGD) discharge regulations
  • Treat and recover valuable products from waste streams
  • Better manage produced water

Panorama offers complete thermal and non-thermal ZLD solutions to manage tough-to-treat wastewaters. Panorama’s solutions can help recover more than 95% of your plant’s wastewater.

Design of Water Reclamation System

Water reclamation systems design

Urban water reuse is a term generally applied to the use of reclaimed water for the beneficial irrigation of areas that are intended to be accessible to the public, such as golf courses, residential & commercial landscaping, parks, athletic fields, roadway medians, etc.

Expanded uses for reclaimed water may also include fire protection, aesthetic purposes (landscape impoundments and fountains), industrial uses and some agricultural irrigation.

Reclaimed water is domestic wastewater or a combination of domestic and industrial wastewater that has been treated to stringent effluent limitations such that the reclaimed water is suitable for use in areas of unrestricted public access. Since most areas where reclaimed water is to be used are designated for public access, protection of public health is the primary concern. Although utilization of reclaimed water will be beneficial, there is no guarantee that this source will provide all the water that is needed or desired.

Highly treated reclaimed water that meets the requirements of these guidelines is a valuable water resource. Wastewater treated to urban water reuse standards may be used in lieu of potable water for agricultural irrigation (feed crops), residential/commercial landscape irrigation, dust control, etc. The reclaimed water system is an integral part of the utility system and provides benefits to both the potable water and wastewater utilities.

Some of the substances that can be removed from wastewater include:

  • Suspended solids
  • Volatile organics
  • Semi-volatile organics
  • Oil and grease
  • Hydrocarbons
  • Metals
  • BOD
  • COD
  • Color
  • Odor
  • Hardness
  • Minerals

Reclamation processes:

Wastewater must pass through numerous systems before being returned to the environment. Here is a partial listing from one particular plant system:

  • Barscreens – Barscreens remove large solids that are sent into a grinder. All solids are then dumped into a sewer pipe at a Treatment Plant.
  • Primary Settling Tanks – Readily settable and floatable solids are removed from the wastewater. These solids are skimmed from the top and bottom of the tanks and sent to the Treatment Plant where it’ll be turned into fertilizer.
  • Biological Treatment – The wastewater is cleaned through a biological treatment method that uses microorganisms, bacteria which digest the sludge and reduce the nutrient content. Air bubbles up to keep the organisms suspended and to supply oxygen to the aerobic bacteria so they can metabolize the food, convert it to energy, CO2, and water, and reproduce more microorganisms. This helps to remove ammonia also through nitrification.
  • Secondary Settling Tanks – The force of the flow slows down as sewage enters these tanks, allowing the microorganisms to settle to the bottom. As they settle, other small particles suspended in the water are picked up, leaving behind clear wastewater. Some of the microorganisms that settle to the bottom are returned to the system to be used again.
  • Tertiary Treatment – Deep-bed, single-media, gravity sand filters receive water from the secondary basins and filter out the remaining solids. As this is the final process to remove solids, the water in these filters is almost completely clear.
  • Chlorine Contact Tanks – Three chlorine contact tanks disinfect the water to decrease the risks associated with discharging wastewater containing human pathogens. This step protects the quality of the waters that receive the wastewater discharge.

At various stages in the multistage treatment process, unwanted constituents are separated using

  • Vacuum or pressure filtration,
  • Centrifugation,
  • Membrane-based separation,
  • Distillation,
  • Carbon-based and zeolite-based adsorption, and
  • Advanced oxidation treatments.

Activated carbon is a highly adsorbent form of carbon that is produced when charcoal is heated. It removes impurities via adsorption from both aqueous and gaseous waste.

Membranes allow materials of a certain size or smaller to pass through but block the passage of larger materials. Imaginative arrays of membrane materials in innovative physical configurations are used to separate unwanted solids and dissolved chemicals from tainted water. During operation, purified water diffuses through the micro-porous membranes and collects on one side of the membrane, while impurities are captured and concentrated on the other side.

Today, membranes made from cellulose acetate, ceramics, and polymers are widely used. The applications come in a variety of innovative designs, including tubular, hollow-fiber, plate-and-frame, and spiral-wound configurations. The goals of membrane design are to

  • Maximize the available surface area,
  • Reduce membrane pore size (to allow for the more precise removal of smaller contaminants),
  • Minimize the pressure drop the fluid will experience when flowing through the unit, and
  • Identify more cost-effective system designs.

The addition of oxidizing agents—chemical ions that accept electrons—has proven effective against these microorganisms like waterborne viruses, bacteria, and intestinal protozoa. Today, a variety of advanced oxidation techniques kill such disease agents and disinfect water, thanks to ongoing developments pioneered by the chemical engineering community.

Historically, chlorine-based oxidation has been the most widely used, and it is very effective. However, the transportation, storage, and use of chlorine (which is highly toxic) present significant potential health and safety risks during water-treatment operations. To address these concerns chemical engineers and others have developed a variety of alternative oxidation treatments that are inherently safer, and in many cases more effective, than chlorination. These include Ultraviolet light,Hydrogen peroxide, and Ozone, each of these powerful oxidizing agents destroys unwanted organic contaminants and disinfects the treated water without the risks associated with chlorine use.

Considerations for constructing a water reclamation system:

In planning for urban reuse there are three major issues that must be considered prior to developing such a system.
The first issue is that year round wastewater treatment and disposal are required when designing any wastewater treatment facility. A water balance for the reclaimed water service area is needed to determine how much wastewater will be generated and how much irrigation demand there is for the reclaimed water. The wastewater generated may exceed the reclaimed water demand during portions of any given year. Therefore, a discharge permit, additional storage, or a designated land application site may be required.

The second issue which must be considered is the constituents (e.g. salts) that may be present in the reclaimed water and what effect(s) they may have on the cover crops that will be irrigated. For specialized users such as golf courses, nurseries, etc., a detailed evaluation of the effluent constituents may be necessary in order to determine whether or not they are candidates for urban reuse irrigation.

Third, Urban Water Reuse is not suitable for all wastewater treatment applications. The manpower requirements and permit reporting can make a reuse facility expensive for a small operation. The facility’s operator in responsible charge shall be a Class I Biological Wastewater Operator. Operation of reclaimed water systems requires on-site operation by a Class II Biological Wastewater Operator or higher operator 8 hours per day, 7 days per week. If the operator can monitor from a remote location and receive immediate notification for alarms, a reduced schedule for on-site operation by a Class II Biological Wastewater Operator or higher operator may be considered on a case-by-case basis.

Deciding how best to use wastewater begins with a laboratory analysis of the substances present in the water. Engineers work with each client to specify the laboratory tests that should be performed. Once that information has been obtained, our engineers and the client:

  • Identify the various ways the water can be used in the specific facility
  • Identify the substances to be removed from the water to make it suitable for each use
  • Determine the process needed to re-condition the wastewater for each use
  • Estimate how much water consumption would be saved by recycling and calculate the annual cost of the water
  • Obtain a cost estimate for the required treatment system
  • Compare the cost savings of reduced water consumption to the capital and operating expenses of the treatment system to determine whether the investment in recycling is cost-effective

Why wait? Start building your water reclamation systems design from the best water reclamation design companies now; get help & assistance from the top highly skilled & technical experts.

Waste Reduction Trends

Waste reduction trends

Although manufacturing & industrial units have the highest potential for recycling opportunities and good paybacks they are also immune to delaying or ignoring the benefits for a eco-friendly greener environment. Even the initial stages of compiling data can be a big task for some units depending upon the size of the facility but usually; the larger the task is for preparation the larger the paybacks are.

The trend for implementation of recycling programs at these units & facilities is definitely on the rise. There are various ways to enhance recycling at manufacturing plants despite the facility being big or small. Apart from the direct monetary paybacks, there are immense process streamlining benefits that are also acquired. Many of the waste materials that are generated in the manufacturing processes can be recycled and recovered.

In the case of a chemical factory, which includes more chemical processes or plants, for efficient global waste minimization it is not enough to study and develop individually the several processes because this might result in a local optimum. The improvements at the different processes are to be investigated and coordinated on a higher, second level, on the factory level and it is also necessary to study together the processes to minimize the waste emission in entire factory.

Recycling Tips

  1. Determine the types of recyclable materials that are being discarded and the approximate volume per week or per month for each of the recyclables materials.
  2. Determine where the largest bulk of these materials is originating within the facility such as the department or work stations of whatever other common ground you are able to pinpoint.
  3. Determine the best manner or the best means by which the work flow or work routines could be changed in order to easily separate these materials out from the waste stream while also avoiding major distractions or inefficiencies to the existing routines and work flows. Basically you are looking for the greatest impact for recovering the recyclable materials with the least impact on worker productivity. If the procedures involving the recycling program are much too cumbersome, intrusive, inefficient or demanding on the employees the recycling program will have little chance of succeeding.
  4. Create a ‘Recycling Manual’ that can be referred to not only by existing employees but new employees as well. This will serve as an important point of reference as the recycling program grows and becomes more and more efficient with time. The manual should also include before and after information that highlights the amount of money and recyclables being saved as a result of the recycling program. As these numbers grow it will create more and more incentive for the employees to come up with new ideas for achieving additional benefits from the program. It will also give them a clear picture of how mismanaged a company can be when they don’t recycle.

 

Again, recycling and manufacturing programs can seem daunting to implement but the benefits to business and the environment as well as huge cost savings through government incentives and general bottom line gains are well worth the effort.

Let’s take a look at recycling trends in the near future that have the potential to change the industry:

  • Biodegradable plastics:
    Other than bans on plastic, the concept of biodegradable plastics is an innovative step in the right direction. Experts have been able to develop biodegradable plastics using plant derived resins; although the fact still remains that without proper systems in place to break down and recycle the plastics, we face a major risk of contaminating entire batches of recycling.Biodegradable plastics still face a lot of skepticism, even in the face of major demand, but they definitely offer hope for industries that rely on plastic-based products for packaging, transportation and storage.The market for biodegradable plastic resins has been increasing steadily for years and is currently expected to increase by 19% a year into 2017.
  • Composting:
    Only 5% of the 26 million tons of food waste in 2012 avoided a landfill. This means there are still millions of tons of food sitting at the bottom of a landfill that could have otherwise been turned into a healthy compost material for personal or municipal use. Hence, municipalities across the country are pushing to make composting a mandatory practice in order to create healthy compost for personal or municipal use. With vegetable matter ending up in a compost pit instead of the garbage bin, the potential for sustainable, healthy and eco-friendly produce can grow in leaps and bounds.

What will it take for industry to move into-the lead here? We have five suggestions:

  1. Top corporate managements must become more aware and convinced of the many potential advantages that they may derive from waste reductions.
  2. Companies need to put in place information systems on the plant level that track the movement of hazardous substances, the type of waste audit systems we have in mind would identify individual chemicals entering the plants, indicating how much of each chemical is discharged as waste and into what environmental media. This would consequently identify how much of each chemical is being lost and where.
  3. Companies need to establish accounting systems that will allow them to quantify all raw material, handling and disposal costs and will allow them to define the savings to be made by investments in waste reduction strategies of various kinds.
  4. Companies need to develop a top management focus on waste reduction. This may well be accomplished by appointing a vice president directly responsible for waste reduction company-wide. This official would be the one to oversee shaping the kinds of information and accounting systems described above.
  5. Companies need to create specific incentives which motivate plant managers to aggressively look for waste reduction opportunities and document the results; for example, bonuses given for specific waste reductions achieved.

Other changes to watch include a greater focus on corporate responsibility, e-waste management and the creation of sustainable energy from organic waste in the years to come.

Want to know how Panorama can ensure a sustainable innovation for your manufacturing unit? Contact us now!

Biowaste Decontamination System

Biowaste decontamination systems

Decontamination of biowaste is essential to ensure that pathogenic organisms which can pose a risk to the environment are neutralized. Companies dealing in biowaste decontamination systems should ensure that all active organisms are completely neutralized and the effluent pH & temperature are within acceptable ranges prior to discharge. Decontamination can be done in either in batches or in a continuous process.

  • Batch Process: Heat, hold and cool a finite amount of material on batch basis
  • Continuous: Constant process stream with heat recovery

Panorama has designed unique bio-waste decontamination solutions aimed at decontaminating effluents containing viruses, bacteria and other bio-hazards.

Special features

  • Control of the inactivation parameters (temperature-time)
  • Appropriate selection of materials of construction as per biowaste content
  • All-welded tubular design avoids any risk of cross contamination
  • PLC-controlled cycles and records
  • Conformity with pharmaceutical guidelines
  • Compact design, easy operations and low maintenance

Panorama designs continuous heat treatment or sterilization systems especially dedicated to the sterilization of nutritional media before culture.

We also design inactivation systems for inactivation of hazardous media.

Types of Decontamination Systems:

Out of the various types of biowaste decontamination systems, we have explained a few as below:

  1. Thermal Tubular Decontamination Systems:
    Special thermal tubular decontamination systems are designed to satisfy the requirements of vaccine makers and laboratories working with pathogens and to provide them with a level of safety and reliability unmatched by other classical solutions (batch or chemical treatment).
  1. Large scale Biowaste Decontamination Systems:
    Compact and skid-mounted decontamination plants combine the best features of heat treatment with both best components and raw materials to ensure a perfect inactivation of the biowaste.

 

FOCUS ON SAFETY:

  • Redundant control of the inactivation parameters (temperature-time)
  • Construction materials chosen in respect of the aggressiveness of the agents present in the biowaste
  • All-welded tubular design to avoid any risk of cross contamination
  • PLC-controlled cycles (level controlled automatic start-up and shut-down, cleaning cycles) and records.
  • CGMP design, conformity with CFR and pharmaceutical guidelines
  1. Lab Decontamination Plants:
    The small-scale decontamination plant is very compact and designed to fit into a very tight space. Gathering all features of the large-scale system, this unit has been specifically adapted to meet labs and research facilities’ requirements.
  • Electrical heating technology (no steam, no condensates)
  • Unique sterilization scheme to kill all types of pathogens
  • PLC-controlled cycles for a very simple and secure use
  • Perfect tracking of the cycles (visual control of the operations in real time and recording of the past cycles)
  • Unit easy to service
  • Cost effective
  • Purchasing budget affordable for labs

 

Process & Design engineering:

Panorama’s engineering department team of experts will assist you from the basic design of your plant at an early stage of the project by providing you PID, layout and 3-D drawings & also by advising you on the utilities to choose the more profitable solutions.

Our process design solutions will allow you to be sure that your equipment will be made in compliance with your requirements during the design and manufacturing stages (deliveries of detailed mechanical, electrical, fluid and control designs, calculations and data-sheets of components), and during the testing and commissioning (complete documentation package).

Why Panorama for Biowaste decontamination solutions?

  • Standard units for optimized investment budgets
  • Fast track delivery for Life Sciences decontamination systems and on stock for lab decontamination units
  • Short commissioning time (from 1 to 5 days for standard systems)
  • Reduced validation time for a quick start of production