Phytoremediation of Soil in the Wastewater Irrigation Area of the Western of Shenyang

2014 ◽  
Vol 955-959 ◽  
pp. 2046-2049
Author(s):  
Xue Ying Song ◽  
Ru Jing Liang ◽  
Yu Shuang Li ◽  
Wen Juan Sun ◽  
Xiao Jun Hu

The phytoremediation of jointly contaminated farmland soil with Cd and PAHs was studied in the long-term and representative wastewater irrigation area in Northeast China. Black nightshades (Solanum nigrum L), proved to be a Cd-hyperaccumulator was taken to remove the Cd contaminant from soil during one growing seasons in field test and thirteen lawn grasses and pasture grasses were taken to remediate the PAHs in pot experiments. Results showed that the residual concentrations Cd and PAHs were 1.94~3.69 mg/kg (dry weight) and 1.69~2.71 mg/kg (dry weight), respectively, still much higher than the Soil Quality Standard after the stop of wastewater irrigation for more than 20 years. The black nightshades could tolerate and grow well in the jointly contaminated farmland, with the distribution sequence of Cd in the order of leaf> stem> fruit> root, and the removal rate in the high-density black nightshade treatment was 1.40 percent in one growing season, higher than that in the moderate-density treatment and low-density treatment. Alfalfa, rye grass, Balin, tall fescue and white clover were more efficient than others of the tested thirteen grasses for the remediation of PAH-contaminated soil.

2012 ◽  
Vol 430-432 ◽  
pp. 941-948 ◽  
Author(s):  
Yong Sheng Shi ◽  
Yu Zhen Shi ◽  
Lin Wang

Studies have been carried out on removal of Se(Ⅵ) from raw water by ion exchange process. The experiment results indicate that employment of strong-base anion exchange resin of 201×7 can receive a desirable result for Se removal. It is particularly true that the removal rate of Se(Ⅵ) can achieve more than 96% when the Se(Ⅵ) concentration in raw water is 100μg/L. This allows selenium concentration of the supply water in full conformity to the quality standard currently available for drinking water. Ion exchange process for Se removal has been proved to be competent for its efficiency, cost effectiveness and easy operation.


1996 ◽  
Vol 121 (1) ◽  
pp. 115-122 ◽  
Author(s):  
K.I. Theron ◽  
G. Jacobs

Large Nerine bowdenii bulbs (>14 cm in circumference) were exposed to low ligbt intensities for different periods during two successive growing seasons. The flowering percentage and number of florets in the current season's inflorescence were recorded at anthesis. Small and large bulbs were subjected to continual defoliation starting at different times during the growing season. Bulbs were dissected at planting (26 Sept. 1992) and on 12 Jan. 1993 (nondefoliated control bulbs) to determine growth and developmental stage. At anthesis, inflorescences were harvested and the florets per inflorescence were counted. After anthesis in the fall, all bulbs were dissected and the following variables recorded: 1) percentage flowering, quiescence, or abortion of the current season's inflorescence; 2) developmental stage of quiescent inflorescences; 3) number of florets in the outermost inflorescence; 4) developmental stage of the innermost inflorescence; 5) number of leaves or leaf bases in each growth unit; 6) number of daughter bulbs; and 7) dry weight of new leaf bases. There were three reasons for nonflowering of the bulbs, viz., failure to initiate an inflorescence, inflorescences remaining quiescent, and inflorescence abortion. Individual florets that had not reached stage “Late G” (gynoecium elongated, carpels fused) at the start of rapid inflorescence elongation aborted. The more florets that aborted, the greater the probability that the entire inflorescence aborted. The inflorescence was more vulnerable to stress during the first half of the growing season due to its relatively weak position in the hierarchy of sinks within the bulb.


1990 ◽  
Vol 122 (6) ◽  
pp. 1177-1186 ◽  
Author(s):  
Y.S. Xie ◽  
J.T. Arnason ◽  
B.J.R. Philogène ◽  
J.D.H. Lambert ◽  
J. Atkinson ◽  
...  

Abstract2,4-Dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), the major hydroxamic acid present in corn root, was studied for its effects on western corn rootworm, Diabrotica virgifera virgifera (LeConte). Exogenously applied DIMBOA caused mortality in western corn rootworm larvae feeding on fresh corn roots. The LC50 (lethal concentration for 50% mortality) value (fiducial limits) was 153 ppm (108–209) and the LC90 value was 917 ppm (560–2297). The deleterious effects of DIMBOA on western corn rootworm larvae possibly are due to both feeding deterrence and toxicity. In a replicated pot trial during two growing seasons, two corn lines developed by Agriculture Canada from CIMMYT collections, ITR 3872 with high DIMBOA content in roots, and NTR-2 Ger. 4042 with low DIMBOA content in roots, were evaluated for resistance to western corn rootworm larvae. The results indicated that the high DIMBOA line (but not the low DIMBOA line) stressed western corn rootworm larvae to produce inferior adults based on the measurement of adult emergence number, adult weight, and adult head-capsule width. The effect of western corn rootworm on both corn lines with different DIMBOA levels was measured based on plant growth parameters including plant height, stem thickness, plant fresh weight, root fresh weight, plant dry weight, and root dry weight. ITR 3872 (high DIMBOA) showed significantly less damage than NTR-2 Ger. 4042 (low DIMBOA) in almost all plant parameters measured. The results suggest that DIMBOA may in some instances contribute to the resistance of corn to western corn rootworm larvae.


1992 ◽  
Vol 43 (7) ◽  
pp. 1597 ◽  
Author(s):  
JM Wroth ◽  
RAC Jones

In 1989 and 1990, infection with subterranean clover mottle sobemovirus (SCMV) was widespread in subterranean clover ( Trifolium subterraneum L.) pastures in the south-west of Western Australia. The virus was detected in 61% of the pastures sampled and incidences of infection ranged from 1 to 50%. The virus was more common in old pastures than in pastures resown with newer cultivars during the preceeding 5 year period. When 12 isolates of SCMV were inoculated to subterranean clover plants grown in the glasshouse, symptoms varied from mild to severe. SCMV isolates P23 and F4 decreased the herbage dry weight of cw. Daliak and Woogenellup grown in plots as spaced plants by 81-88% while the Type isolate caused losses of 92%. By contrast, losses were 37-49% with cv. Karridale, a cultivar in which systemic infection was either delayed or prevented during winter. Infection decreased seed yield by c. 90% in cvv. Karridale and Woogenellup with all three isolates; seed weight was decreased 21-55%. A small proportion of cv. Woogenellup transplants outgrew the infection in new shoots during late spring to produce abundant healthy foliage. SCMV seed transmission rates in seed collected from infected transplants of cv. Woogenellup were 0.06, 0.07 and 0.43% for the Type, P23 and F4 isolates respectively. It was concluded that SCMV was present in most pastures, but at low incidences, and that it persists in them from year to year. Extended growing seasons and hard grazing are likely to increase its incidence.


2014 ◽  
Vol 1010-1012 ◽  
pp. 595-598
Author(s):  
Gui Fang Liu ◽  
Hong Mei Yan ◽  
Yuan Gao ◽  
Ya Quan Sun ◽  
Yu Ping Zhang

Fenton-oxidation process was used to treat the simulation ship sewage that had met the requirement of IMO discharge standard. The effects of reaction time, doses of H2O2 and FeSO4, pH and temperature on COD removal rate were investigated. The results showed that the optimum condition for treating simulation ship sewage was as follows: pH=3.0, concentration of H2O2=9 mmol/L, concentration of FeSO4=3 mmol/L, and reaction time=30 min. Under the optimum condition, the removal rate of COD was to 62.7%. The water quality of the effluent could meet Miscellaneous Domestic Water Quality Standard.


2011 ◽  
Vol 343-344 ◽  
pp. 340-343
Author(s):  
Ri Cha Hu ◽  
Li Bo Sun

Based on the soil test of heavy metals in wastewater irrigation area in eastern Inner Mongolia, this paper analyses the content of heavy metals Cr, Cu, Cd, Pb in different layers of soil samples and reveals the internal relations between heavy metal concentration gradient in the vertical direction and soil properties, thus providing a scientific basis to guide sewage irrigation, solve the problem of water shortage in wastewater irrigation area and carry out environmental impact assessment. Soil is an important subsystem in natural environmental systems, through which many pollutants, especially heavy metals, produced by human activities, enter the food chain and ultimately do harm to human health. Currently, heavy metal ion contamination to the soil caused by wastewater irrigation has become one of the focuses in the study of soil chemistry and agricultural environment pollution. For this reason, it is particularly important to study the migration mechanism of heavy metals in soil and to provide a reliable theoretical basis for the prevention and management of soil contaminants.


2011 ◽  
Vol 63 (4) ◽  
pp. 598-604 ◽  
Author(s):  
R. S. Kookana ◽  
G-G. Ying ◽  
N. J. Waller

Triclosan (TCS) is an antimicrobial agent used widely in household products such as soaps, household cleaners, cosmetics, sportswear, mouthwash and toothpaste. It is a bioaccumulative compound known for its high toxicity to algae, daphnids, fish and other aquatic organisms. We investigated its occurrence in effluents, biosolids and surface waters in Australia, as well as its fate in Australian soils and wastewater treatment plants (WWTPs), including the effects on microbial processes in soils. The concentrations of TCS in 19 effluents ranged from 23 to 434 ng/L (median 108 ng/L) and in 17 biosolids from 0.09 to 16.79 mg/kg on dry weight basis (median 2.32 mg/kg). TCS at concentrations of up to 75 ng/L were detected in receiving waters from five creeks affected by effluent discharge from WWTPs. The removal rate of TCS in five selected WWTPs ranged from 72 and 93%, ascribed mainly to sorption onto sludge and biological degradation. Biodegradation in a clay loam soil was noted with a half life of 18 days. However the half-lives under field conditions are expected to be very different. The studies on the effect of TCS on soil microbiological processes showed that triclosan can disrupt the nitrogen cyclein sensitive soils at concentrations ≥5 mg/kg. In view of the recent risk assessment by the Australian regulatory agency NICNAS, there is an urgent need to assess exposure to TCS and its effect on ecosystem health.


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