For wastewater with high concentrations of acid and alkali in water, its sources are actually quite extensive and it exists in many industries! For instance, industries such as chemical engineering, acid production, electroplating and some metal processing plants all discharge acidic wastewater. However, the acid concentration in wastewater varies greatly, ranging from less than 1% to over 10%. Production processes such as papermaking and ignition do discharge alkaline wastewater, most of which is inorganic alkali, although there is also some organic alkali.
May I ask what the difference is between pH and total alkalinity?
1.For acidity or alkalinity, it refers to the pH value of hydrogen ion concentration, which is a representation of hydrogen ion activity in a solution. Simply put, it is the standard content of acidity or alkalinity in a solution. As for the total alkalinity, it mainly refers to the combination of bases present in water (including: SO42-, OH-, CO32-, etc.);
2.What factors can influence them?
· pH level, which can be simply understood as the acidity or alkalinity of the aquaculture water body mainly being affected by the concentration of carbon dioxide in the water. During the day, the living plants in the water carry out photosynthesis, which consumes a large amount of carbon dioxide and causes an increase in the pH level. On the contrary, on rainy days, aquatic organisms breathe and release a large amount of carbon dioxide, which causes the pH level of the water to drop.
If the pH level in water is too high or too low, it can directly erode the gills and body surface of aquaculture animals. Additionally, it can also affect algae, bacteria and other microorganisms in the water. This may lead to pathogenic hypoxia and deficiency of trace elements, causing a decline in the immunity of farmed animals. If secondary infections by bacteria occur, diseases may break out and have no other adverse effects!
· As for total alkalinity, it is the ability of water to absorb cations to maintain a constant pH level. The factors that can affect the total alkalinity are the contents of ions such as SO42-, OH-, and CO32- in water. The higher the content of these ions, the higher the total alkalinity of the water will be. At this point, the level of the total alkalinity index will directly affect the physiological functions, algal facies and the stability of growth conditions in aquaculture. If the total alkalinity in the water is higher, the buffering capacity of the aquaculture water body against external aquaculture factors will be stronger, and the pH index of the incoming water body will remain relatively stable. However, some heavy metal ions will precipitate, thereby reducing the toxicity of heavy metal ions. On the contrary, if the total alkalinity value is low, it will cause instability in various physical and chemical indicators of the aquaculture water body, leading to poisoning of aquatic organisms.
To sum up, we understand that water containing pH or total alkalinity cannot be discharged at will. If discharged randomly, it will cause pollution to the environment. What needs to be considered is how to recycle and comprehensively utilize it. Of course, if the water is properly treated before being discharged and online water quality monitoring is done well, for example, using the TOH-8000 Water Quality Alkalinity Online Analyzer to monitor the alkalinity in the water body in real time. Different indicators are monitored by different water quality detectors to ensure that all indicators in the water meet the standards or are discharged.
