Biological processes have high removal efficiencies and low operational costs, but the secondary effluent of coking wastewater (CWW), even at a low concentration, is difficult for microorganisms to degrade directly. In this study, glucose was used as a carbon source and co-metabolic substrate for microbial acclimation in order to enhance the advanced treatment of coking wastewater (CWW). The removal performance of the pollutants, especially recalcitrant compounds, was studied and the changes in the microbial community structure after activated sludge acclimation were analyzed. The effect of glucose addition on the secondary biochemical effluent of coking wastewater (SBECW) treatment by the acclimated sludge was further studied by a comparison between the performance of two parallel reactors seeded with the acclimated sludge. Our results showed that the concentrations of chemical oxygen demand (COD), total organic carbon (TOC), and UV absorption at 254 nm (UV254) of the wastewater decreased in the acclimation process. Refractory organic matter, such as polycyclic aromatic hydrocarbons and nitrogen-containing heterocyclics, in the SBECW was effectively degraded by the acclimated sludge. High-throughput sequencing revealed that microbes with a strong ability to degrade recalcitrant compounds were enriched after acclimation, such as Thauera (8.91%), Pseudomonas (3.35%), and Blastocatella (10.76%). Seeded with the acclimated sludge, the reactor with the glucose addition showed higher COD removal efficiencies than the control system without glucose addition (p < 0.05). Collectively, glucose addition enhanced the advanced treatment of coking wastewater (CWW).
Abstract. With the rapid increase of energy consumption in the cargo transportation system, the problems of energy and environmental should be seriously considered. The freight transport structure should be developed in a more energy-saving and reasonable direction by adjusting freight to achieve the purpose of reducing energy consumption. Considering freight adjustment system itself characteristics, this paper introduced a multi-agent-based model that is constructed individually from government agent, transportation company agent, and cargo owner agent based on demand response. The experiment through the Netlogo proves that freight has played a positive role in regulating the energy consumption of the cargo transportation system and put forward energy saving advices and policies.
As physical and chemical tests alone are not sufficient enough for the assessment of potential effects on aquatic organisms, bioassays are required for the integrated evaluation of water pollution. In this study, invertebrate crustacean Artemia salina (brine shrimp) was applied as an indicator to assess the water quality of Hangzhou Section of Beijing-Hangzhou Grand Canal. The percentage mortality of brine shrimp was recorded after 24-h exposure to the Canal water. The water samples were collected from five typical sites during October 2008 and April 2009. It exhibited 11% ± 8.3%, 26.7% ± 17%, 31.7% ± 8.5%, 28.0% ± 11.7%, and 4% ± 4.3% percentage mortality for the sample from Tangxi Bridge, Yi Bridge, Gongchen Bridge, Maiyu Bridge, and Gujia Bridge in 2008, respectively. And it exhibited 5.7% ± 4.2%, 10.3% ± 8.2%, 24.3% ± 12.3%, 16.0% ± 12.3%, and 0%, percentage mortality in 2009, respectively. According to the results, a relative improvement in water quality was observed, although the results were not significantly different at the p < 0.05 level. It suggested that 24-h A. salina exposure trials represent an acceptable bioassay for water toxicity when alternative bioassays were unavailable.
Wastewater sludge ecological stabilization (WWSES) pilot scale experiments were conducted for thickening treatment and disposal of sludge which came from Cyclic Activated Sludge Technology (CAST) process. The study was performed over the periods from June to November 2005 and from May to November 2006, on a bed of 80 m2. The sludge loadings were stopped for the winter from December 2005 and resumed in May 2006. The results shows that dried sludge layer has higher permeation coefficients of 0.15-1.3 m/h. It is suggested that the percolate did not filtrate downwards evenly, part of percolate filtrates downwards along stems, roots and cracks existing in dried sludge which have lower flow resistance. The relationship of dried sludge thickness and operation time is in accord with quadratic equation under fluctuating sludge loadings. Linear regression equation can indicate dried sludge thickness variation under fixed sludge loading. In comparison with natural ones, coarse protein content of Phragmites australis roots in the system is twice as high, coarse fiber content of roots, coarse fat content of stems and leaf are obviously higher; and coarse protein content of Typha augustifolia in the system are obviously higher, while coarse fat and coarse fiber contents have no significant difference.
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