[Objective] The aim was to research impacts of agricultural non-point pol- lution on water-source region in Songhua Dam, laying foundation for control of water pollution and scientific protection of water-source regio...[Objective] The aim was to research impacts of agricultural non-point pol- lution on water-source region in Songhua Dam, laying foundation for control of water pollution and scientific protection of water-source region. [Method] Water in Muyang River, lengshui River and Zizania aquatica region were sampled to measure content of pollutants in water and conclude relation between water contamination and agri- cultural non-point pollution to find the major cause of pollution. [Result] Organic pollu- tant in Muyang River was higher; N and P contents in Lengshui River were higher; the measured indices in Zizania aquatica region excessively exceeded related stan- dard. [Conclusion] The chemical fertilizers and pesticides are the toxic materials lead- ing to water contamination and constitute a major cause of pollution in Songhua Dam water-source region. Agricultural non-point pollution should be controlled in a scientific way.展开更多
A kinetic model has been developed for the degradation of organic pollutants concerning with hydroperoxide ion as the initial step for generation of hydroxyl radical and its subsequent reaction mechanisms. Rate equati...A kinetic model has been developed for the degradation of organic pollutants concerning with hydroperoxide ion as the initial step for generation of hydroxyl radical and its subsequent reaction mechanisms. Rate equations were derived for depletion of ozone and pollutants in the peroxone oxidation process using ozone and hydrogen peroxide as combined oxidants. Kinetic data obtained experimentally from the hydrogen peroxide-ozone reaction and peroxone oxidation of nitrobenzene were analyzed by using the proposed rate equations.展开更多
Ultrasound (US)-induced cavitation is an effective way in oxidizing organic contaminants in wastewater either as the independent operation unit or in combination with other oxidation methods. In this paper, black liqu...Ultrasound (US)-induced cavitation is an effective way in oxidizing organic contaminants in wastewater either as the independent operation unit or in combination with other oxidation methods. In this paper, black liquor and filtrate after acidifying and settling were sonicated. The effect of working parameters on ultrasonic degradation of black liquor, such as different combination methods, frequency, power supply, initial concentration, pH, duration time, ionic strength and catalyst were studied. The results were as follows: (1) At the conditions of 40kHz, 100W, 4h, pH at 6 and temperature 30?℃, utilizing US/US-H2O2/US-Fenton, weak-orange filtrate turned to colloid with the increase of time and little sediment produced after settling. Especially filtrate came to be milk white collides and upper water approached to nearly achromatic by US-Fenton. Compared with the US, US-H2O2/US-Fenton COD (Chemical oxidation demand) removal ratio can increase 15%, 30% respectively. Because of more hydroxyl radicals produced in the reaction process; (2) At the condition of 100W and 4h, the degradation efficiency of black liquor was better at 40kHz over at 20kHz. Moreover black liquor can be biodegraded easily. Those based on that the big molecule of contaminants in aqueous solution can be changed into the little molecule with ultrasound (3) At the condition of 40kHz and 4h, the COD removal ratio of black liquor was more higher at 60W than at 80W, while the removal ratio of COD at 60W was nearly close to the ratio at 100W; (4) The initial concentration of black liquor influenced the effect of sonochemical degradation; (5) The variation of pH had no effect on degradation; (6) The longer the duration time, the greater the removal ratio of COD. But this ratio increased slowly after 4h; (7) Adding 0.2g/L NaCl to change the ionic strength of the black liquor, the COD removal ratio can increase 10%; (8) The degradation rates increased by the coexistent catalysts of TiO2, Co2+ and Ag+.展开更多
Study on the effects of sonolysis, ozonolysis and US/O3 system on the decomposition of p-chlorophenol in aqueous solutions indicated that in the cases of US/O3 system, individual ozonolysis and sonolysis, the decompos...Study on the effects of sonolysis, ozonolysis and US/O3 system on the decomposition of p-chlorophenol in aqueous solutions indicated that in the cases of US/O3 system, individual ozonolysis and sonolysis, the decomposition rate of p-chlorophenol reached 78.78%, 56.20%, 2.79% after a 16-min reaction while its CODcr (chemical oxygen demand) removal rate was 97.02%, 62.17%, 3.67% after a 120-min reaction. The decomposition reaction of p-chlorophenol follows pseudo-first-order kinetics. The enhancement factors of p-chlorophenol and its CODcr under US/O3 system reached 63% and 237% respectively. The main intermediates during the decomposition include catechol, hydroquinone, p-benzoquinone, phenol, fumaric acid, maleic acid, oxalic acid and formic acid. The decomposition mechanism of p-chlorophenol was also discussed.展开更多
The term polychlorinated biphenyls, or PCBs refers to a class of synthetic organic chemicals that are, to a large degree, chemically inert. PCBs are not found in a nature as a natural compounds and its appearance in n...The term polychlorinated biphenyls, or PCBs refers to a class of synthetic organic chemicals that are, to a large degree, chemically inert. PCBs are not found in a nature as a natural compounds and its appearance in natural environment is connected with unintentional and irresponsible human activity. PCBs have been produced on an industrial scale for more than 50 years and have been exported as chemicals in products to almost every country in the world. PCBs were commonly used as dielectric fluids in transformers and capacitors, in heat transfer and hydraulic systems. Other uses of PCBs included the formulation of lubricating and cutting oils, as plasticizers in paints. Nowadays PCBs are ranked among the compounds called POP （Persistent Organic Pollutants）. This group of hazard removable pollutants includes pesticides, dioxins and furans also. Fishes fished from August 2006 to December 2007 from lakes in north-east Poland： Lafiskie, Kisajno and Niegocin. The investigations were carried out on four fish species： roach, common bream, perch and pike. According to the preliminary mass and length measurements anticipatory treatment were realized. Subsequently fishes were analysed in accordance with National Institute of Hygiene method. According to the investigations results PCBs were found in fish muscular tissues, fished from north-east lakes. PCB level didn＇t exceed the highest acceptable daily dose （4pg-TEQ body mass/day）.展开更多
Mine tailings, waste rock piles, acid mine drainage, industrial wastewater, and sewage sludge have contaminated a vast area of cultivable and fallow lands, with a consequence of deterioration of soil and water quality...Mine tailings, waste rock piles, acid mine drainage, industrial wastewater, and sewage sludge have contaminated a vast area of cultivable and fallow lands, with a consequence of deterioration of soil and water quality and watercourses due to the erosion of contaminated soils for absence of vegetative cover. High concentrations of toxic elements, organic contaminants, acidic soils, and harsh climatic conditions have made it difficult to re-establish vegetation and produce crops there. Recently, a significant body of work has focussed on the suitability and potentiality of biochar as a soil remediation tool that increases seed emergence, soil and crop productivity, above ground biomass, and vegetation cover on mine tailings, waste rock piles, and industrial and sewage waste- contaminated soils by increasing soil nutrients and water-holding capacity, amelioration of soil acidity, and stimulation of microbial diversity and functions. This review addresses： i） the functional properties of biochar, and microbial cycling of nutrients in soil; ii） bioremediation, especially phytoremediation of mine railings, industrial waste, sewage sludge, and contaminated soil using biochar; iii） impact of biochar on reduction of acid production, acid mine drainage treatment, and geochemical dynamics in mine railings; and iv） treatment of metal and organic contaminants in soils using biochar, and restoration of degraded land.展开更多
文摘[Objective] The aim was to research impacts of agricultural non-point pol- lution on water-source region in Songhua Dam, laying foundation for control of water pollution and scientific protection of water-source region. [Method] Water in Muyang River, lengshui River and Zizania aquatica region were sampled to measure content of pollutants in water and conclude relation between water contamination and agri- cultural non-point pollution to find the major cause of pollution. [Result] Organic pollu- tant in Muyang River was higher; N and P contents in Lengshui River were higher; the measured indices in Zizania aquatica region excessively exceeded related stan- dard. [Conclusion] The chemical fertilizers and pesticides are the toxic materials lead- ing to water contamination and constitute a major cause of pollution in Songhua Dam water-source region. Agricultural non-point pollution should be controlled in a scientific way.
基金Supported by Guangdong Province Natural Scientific Foundation(No.970457).
文摘A kinetic model has been developed for the degradation of organic pollutants concerning with hydroperoxide ion as the initial step for generation of hydroxyl radical and its subsequent reaction mechanisms. Rate equations were derived for depletion of ozone and pollutants in the peroxone oxidation process using ozone and hydrogen peroxide as combined oxidants. Kinetic data obtained experimentally from the hydrogen peroxide-ozone reaction and peroxone oxidation of nitrobenzene were analyzed by using the proposed rate equations.
文摘Ultrasound (US)-induced cavitation is an effective way in oxidizing organic contaminants in wastewater either as the independent operation unit or in combination with other oxidation methods. In this paper, black liquor and filtrate after acidifying and settling were sonicated. The effect of working parameters on ultrasonic degradation of black liquor, such as different combination methods, frequency, power supply, initial concentration, pH, duration time, ionic strength and catalyst were studied. The results were as follows: (1) At the conditions of 40kHz, 100W, 4h, pH at 6 and temperature 30?℃, utilizing US/US-H2O2/US-Fenton, weak-orange filtrate turned to colloid with the increase of time and little sediment produced after settling. Especially filtrate came to be milk white collides and upper water approached to nearly achromatic by US-Fenton. Compared with the US, US-H2O2/US-Fenton COD (Chemical oxidation demand) removal ratio can increase 15%, 30% respectively. Because of more hydroxyl radicals produced in the reaction process; (2) At the condition of 100W and 4h, the degradation efficiency of black liquor was better at 40kHz over at 20kHz. Moreover black liquor can be biodegraded easily. Those based on that the big molecule of contaminants in aqueous solution can be changed into the little molecule with ultrasound (3) At the condition of 40kHz and 4h, the COD removal ratio of black liquor was more higher at 60W than at 80W, while the removal ratio of COD at 60W was nearly close to the ratio at 100W; (4) The initial concentration of black liquor influenced the effect of sonochemical degradation; (5) The variation of pH had no effect on degradation; (6) The longer the duration time, the greater the removal ratio of COD. But this ratio increased slowly after 4h; (7) Adding 0.2g/L NaCl to change the ionic strength of the black liquor, the COD removal ratio can increase 10%; (8) The degradation rates increased by the coexistent catalysts of TiO2, Co2+ and Ag+.
文摘Study on the effects of sonolysis, ozonolysis and US/O3 system on the decomposition of p-chlorophenol in aqueous solutions indicated that in the cases of US/O3 system, individual ozonolysis and sonolysis, the decomposition rate of p-chlorophenol reached 78.78%, 56.20%, 2.79% after a 16-min reaction while its CODcr (chemical oxygen demand) removal rate was 97.02%, 62.17%, 3.67% after a 120-min reaction. The decomposition reaction of p-chlorophenol follows pseudo-first-order kinetics. The enhancement factors of p-chlorophenol and its CODcr under US/O3 system reached 63% and 237% respectively. The main intermediates during the decomposition include catechol, hydroquinone, p-benzoquinone, phenol, fumaric acid, maleic acid, oxalic acid and formic acid. The decomposition mechanism of p-chlorophenol was also discussed.
文摘The term polychlorinated biphenyls, or PCBs refers to a class of synthetic organic chemicals that are, to a large degree, chemically inert. PCBs are not found in a nature as a natural compounds and its appearance in natural environment is connected with unintentional and irresponsible human activity. PCBs have been produced on an industrial scale for more than 50 years and have been exported as chemicals in products to almost every country in the world. PCBs were commonly used as dielectric fluids in transformers and capacitors, in heat transfer and hydraulic systems. Other uses of PCBs included the formulation of lubricating and cutting oils, as plasticizers in paints. Nowadays PCBs are ranked among the compounds called POP （Persistent Organic Pollutants）. This group of hazard removable pollutants includes pesticides, dioxins and furans also. Fishes fished from August 2006 to December 2007 from lakes in north-east Poland： Lafiskie, Kisajno and Niegocin. The investigations were carried out on four fish species： roach, common bream, perch and pike. According to the preliminary mass and length measurements anticipatory treatment were realized. Subsequently fishes were analysed in accordance with National Institute of Hygiene method. According to the investigations results PCBs were found in fish muscular tissues, fished from north-east lakes. PCB level didn＇t exceed the highest acceptable daily dose （4pg-TEQ body mass/day）.
文摘Mine tailings, waste rock piles, acid mine drainage, industrial wastewater, and sewage sludge have contaminated a vast area of cultivable and fallow lands, with a consequence of deterioration of soil and water quality and watercourses due to the erosion of contaminated soils for absence of vegetative cover. High concentrations of toxic elements, organic contaminants, acidic soils, and harsh climatic conditions have made it difficult to re-establish vegetation and produce crops there. Recently, a significant body of work has focussed on the suitability and potentiality of biochar as a soil remediation tool that increases seed emergence, soil and crop productivity, above ground biomass, and vegetation cover on mine tailings, waste rock piles, and industrial and sewage waste- contaminated soils by increasing soil nutrients and water-holding capacity, amelioration of soil acidity, and stimulation of microbial diversity and functions. This review addresses： i） the functional properties of biochar, and microbial cycling of nutrients in soil; ii） bioremediation, especially phytoremediation of mine railings, industrial waste, sewage sludge, and contaminated soil using biochar; iii） impact of biochar on reduction of acid production, acid mine drainage treatment, and geochemical dynamics in mine railings; and iv） treatment of metal and organic contaminants in soils using biochar, and restoration of degraded land.
