Experimental Study On Ecological Treatment Of Chemical Experiment Wastewater

With the rapid development of higher education in China, there appear more and more laboratories, whose scale is larger and larger. Wastewater generated by the chemical labs with a lot of hazardous and toxic substance, had posed a great threat to the environment. However, so far there have been few reports to study their treatment.This report is made by regarding the wastewater generated by the labs of our academy as a studying object, researching and counting the reagent, chemical medicine used by labs and their dosage, using CODcr and BOD5 as main indexes, and surveying the chemical wastewater for a sustaining period of time. In this report, the chemical wastewater is proved to be light concentration, which can be treated by the way of biology-zoology combined with activated sludge and constructed wetlands ecosystem, and can be studied by setting up pint-sized analog ecosystem in the lab. The main content is following:The activated sludge is acclimated by confecting analog chemical wastewater from some organic contaminations like phenol, toluene, acetic acid and so on. After acclimatization, its main index is MlSS to 3896.5mg per L and SVI to 130mg per L. And furthermore, the tolerance experiment about activated sludge are carried on by changing the concentration of water, staying time , ph and temperature .Finally, the result of this experiment indicates the acclimated activated sludge has a good lowering ability for the chemical waste water ,and can adapt biggish environment changes.The yellow soil, fly ash and sand and stone are analyzed for their abilities of clearing from the impurities to choose the best combination of soil stuffing, in which stuffing is 60cm thick, fly ash covers 5 percent ,and sand and stone are in the ratio of 3 to 1. The acclimated activated sludge added to the soil stuffing in two ways, the PVC tube used which is 160 cm high and whose inside diameter is 110cm, the pint-sized soil stuffing columniation is set up in the lab.The result indicates of the above system used to treat the chemical waste:1. When the CODcr concentration of chemical wastewater changes between 22.70mg per L and 951.48 mg per L, the clearing CODcr rate of soil stuffing columniation can keep over 60 percent. If it changes between 120mg per L and 200mg per L, CODcr concentration keeping between 10mg per L and 30mg per L, the rate can reach to over 85 percent and very stable .2. When the BOD5 concentration of chemical wastewater changes between 30mg per L and 340mg per L, the clearing BOD5 rate keeps about 90 percent. That's very good.3. the clearing effect of total N in the chemical waste water is related to the ratio C/N of it .As a whole , the average clearing rate is about 64 percent.4. The contrast experiment of adding the acclimated activated sludge in the soil stuffing columniation or not, indicates the soil sludge with acclimated activated sludge can get a better effect than that without it. That means it's a practical way to use the acclimated activated sludge consolidating microbial function.So the pint-sized soil stuffing columniation in the lab is successful in dealing with the chemical laboratory wastewater. It lays the foundation for using the way of biology-zoology to treat chemical laboratory wastewater.