Study About Pbdes And Heavy Metal Pollution Characteristics Of Typical Printed Circuit Board Production Enterprise And Impact On Typical Regional Environment

PCB (Printed Circuit Boards) industry are the most active industry among the Contemporary Electronic Components Industry. According to investigation of the China Electronics industry Association, the PCB production output value of China in2003was￥50.069billion, which is more than the United States, after Japan, ranking second in the world. On the other hand, due to the severe pollution of PCB industry, a large number of PCB manufactory were moved into China from other country, such as Japan, South Korea and so on, which make the Heavy metals and PBDEs pollution more aggravated in China. However, there were few study focus on the pollution which was made during the PCB process. So, our study is made to focus on the Heavy metals and PBDEs pollution during the PCB process.In this study, reliable analysis and instrument method for qualitative and quantitative determination of Heavy metals and PBDEs in different environment mediums were built up. After literature survey and field investigation, we chose a typical PCB manufacturing enterprises as our main research object. Then we sampling raw material, wastewater, sludge, particular matters and dust during the PCB process. In raw material, Cu is the highest concentration metal, which concentration is between28000-438000mg/kg, followed by Zn> Pb> Ni> Cd. There is almost none of PBDEs. In wastewater, Cu (1.14±0.71mg/L) is the highest concentration metal, followed by Pb (0.09±0.03mg/L), Ni (0.04±0.01mg/L) and Cd (N.D.). There is almost none of PBDEs. In sludge, Cu ((1.71±0.49)×105mg/kg dw) is the highest concentration metal, followed by Ni (1640.36±484.77mg/kg dw), Pb (791.63±112.05mg/kg dw) and Cd (N.D.). The concentration of PBDEs in wastewater is0.02±0.01mg/kg dw, respectively.The concentration of TSP (total suspended particulate matter), PM10and PM2.5(particular matter diameter below10and2.5μm) in the workshop atmosphere during the PCB process are6.1-365.3,27.1-289.8and22.1-212.3μg/m3, respectively. The correlation between TSP, PM10and PM2.5is very well, and the proportion of PM2.5in TSP is between50%and80%.In TSP, PM10and PM2.5, Zn is the highest concentration metal, followed by Cu>Pb≈Cr> Ni> Cd. There is almost none of PBDEs in PM10.The particle size range of dust in the workshop during the PCB process is between0.3and750μm, in which the proportion of PM2.5and PM10are5.59-10.72%and14.22-26.15%, respectively. The volume average diameter (D(4,3)) of dust sample are in the following order: Drilling (47.83μm)> Raw materials warehouse (44.11μm)> Lamination (41.53μm)> Profiling (37.37μm)> Milling (32.76μm)> Cut lamination (31.23μm). In dust, Cu (6.54-56.31mg/g) is the highest concentration metal, followed by Zn (0.77-4.47mg/g), Pb (0.26-0.49mg/g), Cr (0.39-1.59mg/g), Ni (0.13-0.41mg/g) and Cd (nd-0.056mg/g). There is almost none of PBDEs in dust except a little of BDE-209. Then we take a risk assessment about the six heavy metal in each workshop, the HQ value for each non-carcinogenic metal via all three exposed way (ingestion, inhalation and dermal contact) are all below the safe value1, it indicated that there are no obvious non-carcinogenic risk for each heavy metal. However, the carcinogenic risk for Cr are between3.70×l0-5and1.60×10-3,which is higher than the safe value10-6, the carcinogenic risk for Ni and Cd are all below the safe value10-6, it indicated that there are some carcinogenic risk for Cr.In soil samples collect around the PCB manufactory, the concentration of∑11PBDE (except BDE-209) are among1.00to18.43ng/g dw, average concentration is7.23ng/g dw; The concentration of BDE-209are among3.50to330.0ng/g dw, average concentration is69.88ng/g dw. Obviously, BDE-209is the major congeners, and it contribution77.82%～96.45%(average:86.57%) for the total PBDEs. In dust samples collect around the PCB manufactory, the concentration of∑11PBDE (except BDE-209) are among16.00to258.2ng/g dw, average concentration is113.8ng/g dw; The concentration of BDE-209are among216.1to1947ng/g dw, average concentration is983.8ng/g dw. Similar to PBDEs in soil sample, BDE-209is also the major congeners, and it contribution67.52%～86.54%(average:76.57%) for the total PBDEs. PBDEs concentration decreases gradually with the increase of distance, the sampling site far from the PCB manufactory. This indicate that the PCB manufactory is the source of PBDEs release. Moreover, there are some abrupt phenomenon within PBDEs in soil samples, this indicate that PCB manufactory is not the only source of PBDEs release, there are some other source.In sludge samples collected from a typical Sewage Treatment Plant, PBDEs concentration are between4226.76and9204.14ng/g dw. BDE-209is the dominate congeners, which contribute75.75～89.48%of the total PBDEs, followed by BDE-99> BDE-47> BDE-28, BDE-183, and BDE-153> BDE-15, BDE-100, BDE-154and BDE-206> BDE-203, BDE-207and BDE-208. PBDEs concentration in influent and effluent are183.11ng/L and7.07ng/L, respectively, indicate about98%of PBDEs in influent is removed during the STP. Similar to PBDEs in sludge, BDE-209is the dominate congeners, which contribute75.75%-85.68%of the total PBDEs, followed by BDE-99and BDE-47. Research about the partition coefficient of PBDEs in solid phase and dissolved phase has shown that soluble particulate matter is a key factor for the migration and transformation of PBDEs during STP process. The mass loading of PBDEs in this STP is estimated as21311.2mg/d. There are58.07%and39.91%of total PBDEs removed from the wastewater when wastewater is treated by primary sedimentation tank and secondary sedimentation tank, in other words, there are only2.02%of PBDEs in effluent. And the mass of PBDEs release via effluent and dewater sludge are estimated as420.8mg/d and20880.4mg/d, respectively. The PBDEs in sediment from the Wastewater Receiving Stream indicate that effluent of STP is a source of PBDEs release.Twenty-eight sediment samples were collected from the Taihu Lake and analyzed to acquire information about the levels, distribution, possible sources, time trend and inventory of polybrominated diphenyl ethers (PBDEs) in the Taihu Lake. Our results showed that the most abundant BDE congeners in surface sediments were BDE-47,-99and-209, with a median value of0.124,0.279, and22.72ng/g dw, respectively. The levels of BDE-209in our samples were much higher relative to those of the other BDE congeners and made up more than80%of the PBDEs levels in almost all samples. Disregarding BDE209, among the seven PBDEs (BDE-28,-47,-99,-100,-153,-154,-183) more concerned, the most abundant ones were BDE-47and-99, which contributed44.65%(ranged from29.02%to73.11%),24.24%(ranged from2.27%to39.66%) to∑7PBDEs, respectively. The correlation between PBDE and TOC was poor, indicating that PBDEs concentrations in sediments of the Taihu Lake were controlled not only by TOC contents, but also by a combined effect of transport, mixing, depositional mechanisms associated with PBDEs, uncontaminated sediments, or fresh input of PBDEs. As expected, the time trend of PBDEs concentration in surface sediment from Taihu Lake were increasing, and the inventory of E25PBDEs and BDE-209were estimated to be3668kg and26296kg. In the surface sediment from Taihu Lake, the concentration of Cu, Zn, Pb, Cd and Ni are0.79-113.79mg/kg (62.04±30.43mg/kg),80.7-285.10mg/kg (144.92±45.57mg/kg),57.28-117.52mg/kg (88.84±15.04mg/kg),0.09-1.00mg/kg (0.53±0.26mg/kg) and33.45-82.54mg/kg (56.84±15.16mg/kg), respectively. According to the correlation analysis, the correlation among these heavy metals are not well, this indicate that the source of these heavy metals are different. Moreover, the PCA (Principal component analysis) manifest that there are three main source of these heavy metals:Anthropogenic emissions, Atmospheric deposition and Natural weathering.The concentration of∑PBDEs and BDE-209in surface sediment from East China Sea(ECS) are between0.20to2.09and0.57to2.87ng/g dw, respectively. BDE-209is the dominate congeners, contribute57.9-76.7%of total PBDEs, followed by BDE-99and BDE-47, which contribute11.7-21.5%and7.1-17.4%of total PBDEs, respectively. Moreover, the concentration of PBDEs decreased within the increase of distance between sampling site and coastline, rise from north to south. This indicate that, in surface sediment from ECS, PBDEs are mainly derived from the inland river transportation and atmospheric deposition, and the distribution of PBDEs are influenced by ocean current, TOC (Total Organic Carbon,%) and atmospheric deposition. The concentration of PBDEs in core sediment from ECS is well matching the history and status of PBDEs in China. The TOC content in surface and core sediment from ECS are between0.54to0.88%and0.62to0.88%, respectively. And the correlation between TOC and PBDEs in both surface and core sediment are very well, the correlation coefficient are R2=0.723(p<0.01) and R2=0.595(p<0.01) for surface and core sediment, respectively. This further indicate that TOC is a key factor for the distribution of PBDEs in sediment.