Glass is ubiquitous in our daily lives, but how much do we know about glass factories? What negative impacts arise during the manufacturing of glass? Among these, the wastewater generated contains certain pollutants, which can cause water source pollution and further harm the ecological environment and human health. This chapter analyzes the wastewater monitoring work for flat glass factories.

In China’s glass industry, the direct discharge of untreated manufacturing wastewater still exists in some cases. This is clearly unacceptable! The consequences of inadequate treatment and monitoring would be unthinkable. Firstly, mechanical grilles are used to remove cullet and other large suspended solids for waste recycling. This prevents clogging of lifting pumps, pipelines and other equipment. The adjustment tank stabilizes the wastewater quality, pH value, water temperature, etc., to minimize the shock load on subsequent treatment structures. The wastewater is then pumped into a sedimentation tank for suspended solids removal, and an oil separation tank is used to remove grease and oils from the water.

After a series of treatment processes, a water quality monitor is employed to test various indicators in the wastewater, so as to determine whether the pollutant levels meet the discharge standards.

So, what specific pollutants should be monitored in flat glass factory wastewater? They can be analyzed from the following aspects:

1.Total wastewater discharge outlet (the final outlet for all wastewater streams):

More comprehensive monitoring is required here, including:

pH value, ammonia nitrogen, suspended solids (SS), total phosphorus (TP), total nitrogen (TN), chemical oxygen demand (COD), petroleum oils, fluoride, sulfide, volatile phenols, and total zinc (heavy metal).

2.Cooling water discharge outlet:

Only routine indicators need to be tested, such as:

pH value, COD, and ammonia nitrogen.

3.Wastewater outlet from desulfurization wastewater treatment facilities:

Monitoring focuses mainly on heavy metals, including:

total arsenic, total nickel, total chromium, total cadmium, total lead, etc.

4.Stormwater discharge outlet:

Common across many industries, the monitoring items for glass factories include:

COD (chemical oxygen demand), suspended solids, petroleum oils, volatile phenols, total cyanide, and ammonia nitrogen.

A further reminder: if no harmful substances are detected during monitoring, the monitoring frequency may be relaxed—for example, extending from once a month to once a year, or even longer intervals. Naturally, this should be determined based on the actual water quality conditions. However, it is important to understand that water quality monitoring ensures water safety and must not be ignored when necessary.