Trimethylolpropane (TMP) wastewater is one of the most toxic petrochemical wastewater. Toxicants with high concentrations in TMP wastewater often inhibit the activity of microorganisms associated with biological treatment processes. The hydrolysis acidification process (HAP) is widely used to pretreat petrochemical wastewater. However, the effects of HAP on the reduction of wastewater toxicity and the relevant underlying mechanisms have rarely been reported. In this study, an HAP reactor was operated for 240 days, fed with actual TMP wastewater diluted by tap water in varying ratios. The toxicity of TMP wastewater was assessed with the inhibition ratio of oxygen uptake rate. When the organic loading rates were lower than 7.5 kg COD/m3/d, the toxicity of TMP wastewater was completely eliminated. When the actual TMP wastewater was directly fed into the reactor, the toxicity of TMP wastewater decreased from 100% to 34.9%. According to the results of gas chromatographymass spectrometry analysis, four main toxicants contained in TMP wastewater, namely, formaldehyde, 2-ethylacrolein, TMP and 2-ethylhexanol, were all significantly removed, with removal efficiencies of 93.42%, 95.42%, 72.85% and 98.94%, respectively. Compared with the removal efficiency of CODCr, the reduction rate of toxicity is markedly higher by HAP. In addition, the change of microbial community in the HAP reactor, along the operation period, was studied. The results revealed that, compared with the seed sludge, Firmicutes became the dominant phylum (abundance increased from 0.51% to 57.08%), followed by Proteobacteria and Bacteroidetes (abundance increased from 59.75% to 25.99% and from 4.70% to 8.39%, respectively).
Emissions from industrial activities pose a serious threat to human health and impose the need for monitoring both inorganic and organic pollutants in industrial areas.We selected Masson pine (Pinus massoniana L.) as potential biomonitor and collected the current (C) and previous year (C+1) needles from three industrial sites dominated by petrochemical,ceramics manufacturing,and iron and steel smelting plants and one remote site to determine heavy metals (Cu,Cd,Pb,Zn,Cr,Ni and Co) and polycyclic aromatic hydrocarbons (PAHs) in unwashed and water-washed needles.Both unwashed and washed C+1 needles showed generally higher concentrations of heavy metals and PAHs than C needles,although the washed needles more clearly spotlighted the accumulation effect of PAHs over exposure time.Water-washing resulted in a significant decrease in needle PAH concentrations with more significant effects shown in C needles.By contrast,needle heavy metal concentrations were much less affected by washing.Although heavy metals and PAHs might differ in adsorption and uptake strategies,their higher concentrations in the needles at the industrial sites indicated conspicuous contamination due to industrial emissions there,The PAH distribution patterns in pine needles accorded with the real types of energy consumption in the study sites and were efficiently used for pinpointing local pollutant sources. 相似文献
Environmental Geochemistry and Health - The spatial distribution, pollution level, and exposure risk of Pb in the finer dust (particle size?<?63 μm) of residential... 相似文献
