However, in terms of wastewater management, cost has always been one of the considerations for chemical companies. Therefore,Minimizing the amount of wastewater as much as possible has become the best way to reduce the cost of wastewater treatmentWastewater treatment can combine biological, chemical, and physical treatment methods based on flow rate and pollution load, as well as drainage quality requirements. On site investment in water recycling can quickly offset emission fines and water extraction costs. This is where the overall water footprint and water cost of the entire factory come into play. To achieve on-site water reuse, advanced treatment technologies such as ultraviolet (UV), ion exchange, activated carbon, and reverse osmosis are usually required. The requirements for water treatment usually depend on the purpose of water recovery, for example, the quality of cooling water should be lower than that of boiler feedwater.

Various guidelines aim to limit manufacturing emissions and encourage industries to operate more efficiently and sustainably. For example, the industrial emissions directive of EU member states proposes Best Available Techniques (BAT) and Associated Emissions Levels (AEL) to guide departments on how to achieve compliance and improvement. Similarly, the Clean Water Act in the United States is constantly evolving to promote improvements in wastewater treatment and prevent pollution or toxic incidents. At the enterprise level, many companies have currently released environmental protection projects and long-term water quality goals, and regularly update the latest progress. Although some goals may be relatively low, it is a responsible performance for shareholders, customers, and local communities.

One of the key pointsBAT technologyMonitoring key process parameters at critical locations. The water outlet used to be a monitoring location, butOnly by adding monitoring upstream can optimization and cost savings be truly achievedTo achieve drainage compliance, it is necessary to determine the source of wastewater and its impact on wastewater treatment.

The operator should create a water footprint map of the factory to identify areas where pollution may exist and areas with optimization potential. Then, monitoring points can be added based on the water footprint map,Obtain relevant important data and make decisions on water treatmentThrough the water footprint map, factories can identify current pain points and ensure understanding of the purpose of the data. Collecting laboratory data from the entire factory is usually a good starting point. Initially, if there are no changes between multiple process units, they can be considered non critical points. However, when the treatment stage or steps result in significant changes in water quality or quantity, the operator should consider it as a critical control point.

To determine the parameters to be monitored, in addition to the quality of raw water and drainage,The factory needs to carefully study the on-site handling methods and productsFor example, in the chemical industry, basic or bulk chemicals are plastics and polymers, which are usually important materials for the energy industry and consumer goods. Because the raw materials are organic compounds, the wastewater discharged from the manufacturing of such chemicals usually containsThe organic matter content changes dramatically with production. Therefore, in order to comply with relevant regulatory requirements, many manufacturers design buffer tanks to handle high and low concentrations.

In the field of specialty chemicals, materials are made from inorganic substances such as nitrogen, sulfur, and chloride compounds. Sometimes, organic compounds in the environment or processing can interfere with purity or processing efficiency. For example, chlor alkali production uses saturated saltwater and membrane electrolysis to produce chlorine and related products. There is a risk of organic pollutant accumulation in the recycling of saltwater. Organic pollution can contaminate membrane systems and lead to unplanned maintenance.Tracking pollutants can help protect membrane systems from damage and maintain productivity.

In addition to physical and basic chemical parameters such as temperature, pressure, flow rate, pH value, and conductivity, operators should also consider how they affect process control, compliance, and product quality. As for the substances emitted into the environment, common parameters of concern include organic matter, inorganic matter, and nutrients. Organic matter and nutrients (carbon, nitrogen, phosphorus) can cause algal blooms and eutrophication, affecting the local environment and must be removed through treatment. That's whyMonitoring and eliminating organic pollution is crucial.

Many regions test oxygen demand to indicate the amount of organic matter emitted into the environment. The biological oxygen demand (BOD) is achieved by detecting the biodegradation of compounds in the sample over a period of five days or longer. Due to the interference of disinfectants and cleaning agents, its accuracy and sensitivity are limited. Chemical Oxygen Demand (COD) uses strong oxidants (sometimes toxic) to chemically decompose compounds in the sample within two to three hours. However, COD has no selectivity for organic matter and includes inorganic substances such as nitrite, ammonia, and sulfite. Iron containing compounds can also affect the accuracy of COD detection. This makes it difficult to make actionable decisions during this process. For example, if COD is high, it is difficult to determine whether it comes from organic matter or ammonia. Due to issues of repeatability and sensitivity, it is difficult to ensure a limit below 20 ppm if the BOD in the wastewater is very low, below 20 ppm.

The operator determines TOC by oxidizing organic matter into carbon dioxide and then detecting the resulting carbon dioxide. There are multiple technologies available for detecting TOC, including TOC analyzers and TOC sensors that attempt to associate with the analyzer. The disadvantage of sensors is that although they are faster, they have interference, insufficient recovery of key compounds, and can only capture a portion of organic matter.

There are different oxidation and detection techniques for TOC analyzers, depending on the required applicationWhen detecting the reflux condensate water that combines with boiler feedwater and generates steam, the technology used must be able to determine that there are indeed no pollutants present in the sample. In this case, sensitivity and speed are key to detecting any deviation. For other applications, such as tracking changes in wastewater load and pollution levels, stability is a key attribute required for treating salt, solids, inorganic matter, and high organic loads.

For all applications, the same applies to TOC detection technologyWhat mattersSupport during the successful implementation of the TOC analyzer after its commissioning and the entire process monitoring planIn addition to performance, maintenance, additional parameters, validation, and automation are all factors that need to be considered. When considering cost and water-saving measures, these factors must be taken into account. Analytical tools are designed to help answer questions and drive decisions, so businesses can benefit from opportunities for optimizing wastewater treatment and even on-site recycling.

Improving industrial water management provides chemical companies with opportunities to ensure compliance with constantly changing regulations, improve their public image, meet consumer needs, promote a strong environment and sustainable culture, and reduce costs. In order to achieve these benefits, companies must weigh the effectiveness, compliance, and efficiency of their processing. In addition to wastewater optimization, companies can also understand other potential improvements related to water use through monitoring strategies. For example, they can use actual cleanliness data to improve the use of chemicals and water, rather than making decisions based on estimated cleaning time or cycle times. These data-driven decisions can help chemical companies avoid excessive cleaning, minimize product waste, and save resources. They can also use these monitoring technologies to track the water supply of steam systems to protect equipment such as heat exchangers and condensers from harmful pollutants.

Controlling industrial water use benefits manufacturers in various industries, not only due to compliance and cost, but also because managing industrial water can provide opportunities for improving operations, achieving sustainable development goals, and meeting consumer needs. By monitoring the key control points of the entire factory, the pressure on wastewater treatment can be reduced (especially in consumer oriented industries), thereby better controlling industrial wastewater. Improving pollution tracking technology can help chemical companies make quick decisions, ensure compliance, and seize opportunities for water recycling and reuse.

Author: Amanda Tyndall