Source Survey And Pollution Characteristics Of Toxic And Hazardous Substances (THS) Originated From Dyeing Industry In Liao River Basin

A lot of printing products have been used in our daily lives and many industries,including textiles, cosmetics, newspapers, leather products, pharmaceuticals and foodindustries. Textile printing and dyeing industry as one of the traditional pillar industryof China, produces about2.37billion tons of dyeing wastewater annually, accountingfor11.7%of industrial wastewater enterprises that has been surveyed in our country.Also, because of the large amount of printing and dyeing wastewater, largefluctuations in water quality, complicated composition, high COD and BOD, deepchromaticity, high alkalinity etc. the printing and dyeing wastewater is difficult to betreated and biodegraded. The waste water can be discharged directly or indirectly intonatural waters, causing serious pollution. In particular, some trace organics in waters,due to their toxicity, poor biodegradablility and bioaccumulation, are harmful toaquatic life and human health, some of which have three-induced (carcinogenic,teratogenic, mutagenic) effects, and some have endocrine disrupting effects. Therefore,it is necessary to identify the types and levels of trace organic pollutants in waters andscreen the priority contaminants, so as to understand pollution characteristics of THSsbetter and further establish an efficient strategy for prevention and control of THSs inLiao River Basin.Based on pollution census database, environmental risk source survey andenvironmental risk assessment information, total of120printing companies wereidentified in Liaohe Basin, which located in22different rivers and tributaries in eightprefecture-level cities consisting of Shenyang, Anshan, Fushun, Benxi, Liaoyang,Tieling, Yingkou, Panjin. Hachenghe, Daqinghe and Daliaohe rivers received a large amount of wastewater discharge from24,24and19dyeing enterprises respectively,which accounted for20,20and15.8%of the total printing and dyeing enterprises inLiaohe Basin. Haichenghe received8610724.5t per year of wastewater emissions from24printing and dyeing enterprises, accountingfor51%of total annual wastewateremissions in Liaohe River. Therefore, Haichenghe was selected as the particularreceiving water body and22printing companies were identified as prority-controledenterprises of wastewater emissions according to75%of the total emissionscontrolsThe SPE-GC-MS technique was used to qualitatively determine organicpollutants in effluents from a local integrated wastewater treatment plant within textileindustrial park and also from different sampling sites along Haicheng River. Theresults showed that there were48organic pollutants in the effluent, which mainlyincluded types of N-heterocycles, aliphatic amines, substituted benzenes and alchohols.The diversity of organic pollutants was also observed in each selected section ofHaicheng River, in the site of downstream, however, the majority of pollutants wascomposed of N-heterocycles and substituted benzenes. There were9well-knowntoxic pollutants in total i.e. dimethyl phthalate(DMP), dibutyl phthalate(DBP),di-n-octyl phthalate, p-xylene, aniline, p-dichlorobenzene,4-methyl nitrobenzene,dinitrotoluene and naphthaline that are in both USEPA and Chinese priority pollutantlist.The water samples collected during the dry season, wet season, normal seasonwere extracted for the quantitative analysis of organic pollutants in HaichengheRiver. Internal standard method was used to determine the concentration of eachpollutant in water sample in a different sampling section. In the dry season the higherlevels of esters and phthalate esters, amines and nitrogen-containing heterocyclicorganic compounds aniline were obtained, reaching54.80,35.83and23.63μg/L. Inthe wet period the highest concentrations of phenols, benzene and other substitutedesters and phthalate esterswere607.89,298.22and179.45μg/L. The levels of estersand phthalates, phenols and other substituted benzene were reached392.51,214.33and42.12μg/Lduring the normal season.A―modified hazard potential index (HP) method‖，which took into account the summation of hazard potential values and occurrence possibilities and levels ofpollutants, was applied for the calculation of weighted scores for each contaminant.Based on total score values,44types of contaminants were selected as prioritypollutants in Haicheng River, which comprised types of esters and phthalates (7),N-heterocycles (7), amines and anilines (5), chloro-benzenes (6), nitro-benzenes (5),phenols (7), benzene and substituted-benzenes (5) and polycyclic aromatichydrocarbons (2). The majority of these pollutants were relative to the wastewaterdischarge from printing and dyeing enterprises.