Evolution of microbial populations and impacts of microbial activity in the anaerobic-oxic-settling-anaerobic process for simultaneous sludge reduction and dyeing wastewater treatment

2021 ◽  
Vol 282 ◽  
pp. 124403 ◽  
Author(s):  
Hui Xu ◽  
Bo Yang ◽  
Yanbiao Liu ◽  
Fang Li ◽  
Xinshan Song ◽  
...  
Author(s):  
Xiaozheng Bian ◽  
Jianping Huang ◽  
Lin Qiu ◽  
Chunyan Ma ◽  
Danli Xi

Abstract A new type of polyvinylidene fluoride (PVDF)/polymethyl methacrylate (PMMA) hollow fiber membrane (HFM) with five bores was prepared. The effects of Polyvinylpyrrolidone (PVP), β-cyclodextrine (β-CD), Polyethylene Glycol (PEG) and Polysorbate 80 (Tween 80) and their combinations on the PVDF/PMMA five-bore HFMs were investigated. The performance and fouling characteristics of five-bore HFMs for dyeing wastewater treatment were evaluated. Results indicated that adding 5wt.% PVP could increase the porosity and water flux of the membrane but decrease the bovine serum albumin (BSA) rejection rate. Adding 5wt.% β-CD significantly improved the tensile and rejection of the HFMs without showing effect on the increase of water flux. The characteristic of the HFMs with different additives combinations proved that the mixture of 5wt.% PVP and 1wt.% β-CD obtained the best membrane performance, with a pure water flux of 427.9 L/ m2·h, a contact angle of 25°, and a rejection to bovine serum albumin (BSA) of 89.7%. The CODcr and UV254 removal rates of dyeing wastewater treatment were 61.10% and 50.41%, respectively. No breakage or leakage points were found after 120d operation showing the reliable mechanical properties. We set the operating flux to 55 L/m2·h and cross flow rate to 10% which can effectively control membrane fouling.


2015 ◽  
Vol 768 ◽  
pp. 108-115
Author(s):  
Pan Yue Zhang ◽  
Tian Wan ◽  
Guang Ming Zhang

‘Sonication - cryptic growth’ technology can reduce 30-80% excess sludge in wastewater treatment systems. Various mechanisms contribute to the sludge reduction but the role of each one is unclear. This paper quantitatively studied the potential mechanisms in ‘sonication - cryptic growth’. The operation condition was: every day 20% sludge was sonicated under 1.2 Wml-1 for 15 min and then returned to the wastewater treatment reactor for cryptic growth. The results showed that under such conditions, ‘sonication - cryptic growth’ reduced the excess sludge by 57.3% and the effluent met the national discharge standard. Multiple mechanisms were involved in the process. Detailed analysis showed that the ‘lysis-cryptic growth’ mechanism was the most important one and accounted for 49.1% of sludge reduction. Biodegradation of residual sludge was the second important one and contributed 19.5%. Other potential mechanisms included the altered microbial community, longer sludge retention time, and accumulation of persistent materials. But organic load increase had virtually no impact.


2011 ◽  
Vol 356-360 ◽  
pp. 498-501
Author(s):  
Wen Jie Jin ◽  
Fan Chao Zeng ◽  
Han Xue ◽  
Ying Wang

A kind of new adsorption material for wastewater treatment was made of fly ash as the main composition, with addition of sodium silicate, cement and pore forming material as the accessory materials, etc. Three kinds of practical wastewater were treated by using the new material, they were printing and dyeing wastewater, papermaking wastewater and coking wastewater, respectively. The results showed that removal COD efficiencies of the three kinds of wastewater were 57.89%, 71.43%, 80%, respectively, removal color efficiencies were 90%, 92%, 92%, respectively. The new developed material was mainly used for advanced treatment of the effluent water after biochemical process. It will be a substitute for activated carbon materials and have preferable application prospect.


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