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Elias Broman, Abbtesaim Jawad, Xiaofen Wu, Stephan Christel, Gaofeng Ni, Margarita Lopez-Fernandez, Jan-Eric Sundkvist, Mark Dopson
Wastewaters generated during mining and processing of metal sulfide ores are often acidic (pH < 3) and can contain significant concentrations of nitrate, nitrite, and ammonium from nitrogen based explosives. In addition, wastewaters from sulfide ore treatment plants and tailings ponds typically contain large amounts of inorganic sulfur compounds, such as thiosulfate and tetrathionate. Release of these wastewaters can lead to environmental acidification as well as an increase in nutrients (eutrophication) and compounds that are potentially toxic to humans and animals...
June 2, 2017: Biodegradation
Francisco Ríos, Manuela Lechuga, Alejandro Fernández-Arteaga, Encarnación Jurado, Mercedes Fernández-Serrano
Recently, anaerobic degradation has become a prevalent alternative for the treatment of wastewater and activated sludge. Consequently, the anaerobic biodegradability of recalcitrant compounds such as some surfactants require a thorough study to avoid their presence in the environment. In this work, the anaerobic biodegradation of amine-oxide-based surfactants, which are toxic to several organisms, was studied by measuring of the biogas production in digested sludge. Three amine-oxide-based surfactants with structural differences in their hydrophobic alkyl chain were tested: Lauramine oxide (AO-R12), Myristamine oxide (AO-R14) and Cocamidopropylamine oxide (AO-cocoamido)...
May 31, 2017: Biodegradation
Yi Lu, Xiaoqing Zhang, Lijuan Feng, Guangfeng Yang, Zhou Zheng, Junzhi Liu, Jun Mu
Coupling of biodegradable corncob and plastic carrier was optimized in continuous-flow solid-phase denitrification systems for enhancing simultaneously removal of nitrogen and organics in agricultural runoff. In compared with preposition of plastic carriers and mixed distribution method, it was demonstrated that the preposition of corncobs simultaneously enhanced nitrate (6.64 ± 1.35 mg L(-1) day (-1)) and organics removal (6.33 ± 1.44 mg L(-1) day(-1)) at a hydraulic retention time (HRT) of 6 h...
May 22, 2017: Biodegradation
Weiqiang Zhu, Jin Li, Huiyu Dong, Dan Wang, Peiyu Zhang
Sequencing batch reactors were used to study anaerobic ammonium oxidation (anammox) process under temperature shock. Both long-term (15-35 °C) and short-term (10-50 °C) temperature effects on nitrogen removal performance were performed. In reactor operation test, the results indicated that ammonium removal rate decreased from 0.35 kg/(m(3) day) gradually to 0.059 kg/(m(3) day) when temperature dropped from 35 to 15 °C. Although bacteria morphology was not modified, sludge settling velocity decreased with decreasing temperature...
May 5, 2017: Biodegradation
Jin Li, Weiqiang Zhu, Huiyu Dong, Dan Wang
As an efficient and cost-effective nitrogen removal process, anaerobic ammonium oxidation (ANAMMOX) could be well operated at suitable pH condition. However, pH shock occurred in different kinds of wastewater and affected ANANNOX process greatly. The present research aimed at studying the performance and kinetics of ANAMMOX granular sludge with pH shock. When influent pH was below 7.5, effluent [Formula: see text]-N and [Formula: see text]-N increased with decreasing pH. At Ph 6.0, effluent [Formula: see text]-N approached 100 mg/L, and the ratios of [Formula: see text] approached 2...
April 29, 2017: Biodegradation
Li-Juan Feng, Rong Jia, Jing-Ya Sun, Jing Wang, Zheng-Hui Lv, Jun Mu, Guang-Feng Yang
Understanding the dynamics of performance and bacterial community of biofilm under oligotrophic stress is necessary for the process optimization and risk management in biofilm systems for raw water pretreatment. In this study, biofilm obtained from a pilot-scale biofilm reactor was inoculated into a pilot-scale experimental tank for the treatment of oligotrophic raw water. Results showed that the removal of NH4(+)-N was impaired in biofilm systems when influent NH4(+)-N was less than 0.35 mg L(-1) or NH4(+)-N loading rate of less than 7...
April 28, 2017: Biodegradation
Hui Tong, Manjia Chen, Fangbai Li, Chengshuai Liu, Changzhong Liao
Pentachlorophenol (PCP) has been widely used as a pesticide in paddy fields and has imposed negative ecological effect on agricultural soil systems, which are in typically anaerobic conditions. In this study, we investigated the effect of repeated additions of PCP to paddy soil on the microbial communities under anoxic conditions. Acetate was added as the carbon source to induce and accelerate cycles of the PCP degradation. A maximum degradation rate occurred at the 11th cycle, which completely transformed 32...
June 2017: Biodegradation
P Y Nguyen, Gilda Carvalho, A C Reis, O C Nunes, M A M Reis, A Oehmen
Pure cultures have been found to degrade pharmaceutical compounds. However, these cultures are rarely characterized kinetically at environmentally relevant concentrations. This study investigated the kinetics of sulfamethoxazole (SMX) degradation by Achromobacter denitrificans strain PR1 at a wide range of concentrations, from ng/L to mg/L, to assess the feasibility of using it for bioaugmentation purposes. Complete removal of SMX occurred for all concentrations tested, i.e., 150 mg/L, 500 µg/L, 20 µg/L, and 600 ng/L...
June 2017: Biodegradation
Weiliang Dong, Kuan Liu, Fei Wang, Fengxue Xin, Wenming Zhang, Min Zhang, Hao Wu, Jiangfeng Ma, Min Jiang
Metamifop is universally used in agriculture as a post-emergence aryloxyphenoxy propionate herbicide (AOPP), however its microbial degradation mechanism remains unclear. Consortium ME-1 isolated from AOPP-contaminated soil can degrade metamifop completely after 6 days and utilize it as the carbon source for bacterial growth. Meanwhile, consortium ME-1 possessed the ability to degrade metamifop stably under a wide range of pH (6.0-10.0) or temperature (20-42 °C). HPLC-MS analysis shows that N-(2-fluorophenyl)-2-(4-hydroxyphenoxy)-N-methyl propionamide, 2-(4-hydroxyphenoxy)-propionic acid, 6-chloro-2-benzoxazolinone and N-methyl-2-fluoroaniline, were detected and identified as four intermediate metabolites...
June 2017: Biodegradation
Ling Jiang, Yingxia Tang, Weihua Sun, Na Yi, Yongming Zhang, Hanchang Shi, Bruce E Rittmann
An internal circulation baffled bioreactor was employed to realize simultaneous di-oxygenation of phthalic acid (PA) and denitrification of nitrate, which require aerobic and anoxic conditions, respectively. Adding a small concentration of succinate as an exogenous electron donor stimulated PA di-oxygenation, which produced readily oxidizable downstream products whose oxidation also enhanced denitrification of nitrate; succinate addition also stimulated denitrification. Depending on the concentration of PA, addition of 0...
June 2017: Biodegradation
Nidhi Shrivastava, Ankit S Macwan, Hans-Peter E Kohler, Ashwani Kumar
LinA-type1 and LinA-type2 are two well-characterized variants of the enzyme 'hexachlorocyclohexane (HCH)-dehydrochlorinase'. They differ from each other at ten amino acid positions and exhibit differing enantioselectivity for the transformation of the (-) and (+) enantiomers of α-HCH. Amino acids responsible for this enantioselectivity, however, are not known. An in silico docking analysis identified four amino acids (K20, L96, A131, and T133) in LinA-type1 that could be involved in selective binding of the substrates...
June 2017: Biodegradation
Weiqiang Zhu, Peiyu Zhang, Deshuang Yu, Huiyu Dong, Jin Li
A sequencing batch reactor (SBR) was used to test the nitrogen removal performance of anaerobic ammonium oxidation (ANAMMOX) in presence of organic matter. Mesophilic operation (30 ± 0.5 °C) was performed with influent pH 7.5. The results showed, independent of organic matter species, ANAMMOX reaction was promoted when COD was lower than 80 mg/L. However, specific ANAMMOX activity decreased with increasing organic matter content. Ammonium removal efficiency decreased to 80% when COD of sodium succinate, sodium potassium tartrate, peptone and lactose were 192...
June 2017: Biodegradation
Qingkai Ren, Yang Yu, Suiyi Zhu, Dejun Bian, Mingxin Huo, Dandan Zhou, Hongliang Huo
 A novel micro-pressure swirl reactor (MPSR) was designed and applied to treat domestic wastewater at low temperature by acclimating microbial biomass with steadily decreasing temperature from 15 to 3 °C. Chemical oxygen demand (COD) was constantly removed by 85% and maintained below 50 mg L(-1) in the effluent during the process. When the air flow was controlled at 0.2 m(3) h(-1), a swirl circulation was formed in the reactor, which created a dissolved oxygen (DO) gradient with a low DO zone in the center and a high DO zone in the periphery for denitrification and nitrification...
June 2017: Biodegradation
Zhi-Guo Wu, Fang Wang, Li-Qun Ning, Robert D Stedtfeld, Zong-Zheng Yang, Jing-Guo Cao, Hong-Jie Sheng, Xin Jiang
Several bacteria have been isolated to degrade 4-chloronitrobenzene. Degradation of 4-chloronitrobenzene by Cupriavidus sp. D4 produces 5-chloro-2-picolinic acid as a dead-end by-product, a potential pollutant. To date, no bacterium that degrades 5-chloro-2-picolinic acid has been reported. Strain f1, isolated from a soil polluted by 4-chloronitrobenzene, was able to co-metabolize 5-chloro-2-picolinic acid in the presence of ethanol or other appropriate carbon sources. The strain was identified as Achromobacter sp...
June 2017: Biodegradation
Lamia Ayed, Nedra Asses, Nadia Chammem, Nada Ben Othman, Moktar Hamdi
Table olive processing wastewaters constitute a dangerous environmental problem in the Mediterranean countries because of their large volumes, high organic matter and salt concentration. The quantity and the characteristics of wastewaters produced, and thus, their environmental impact, varied depending on the season, varieties, soil and process employed. Several chemicals, biological and combined technologies have proven effective at bringing down organic pollution and toxicity of these effluents. Advanced oxidation processes have recognized as highly efficient treatments for the degradation of organic matter...
June 2017: Biodegradation
Shiping Zhang, Liang Wang, Wei Wei, Jiajun Hu, Shouhua Mei, Quanyu Zhao, Yiu Fai Tsang
Improved soil carbon sink capability is important for the mitigation of carbon dioxide emissions and the enhancement of soil productivity. Biochar and organic fertilizer (OF) showed a significant improving effect on microalgae in soil carbon sink capacity, and the ultimate soil total organic carbons with microalgae-OF, microalgae-biochar, microalgae-OF-biochar were about 16, 67 and 58% higher than that with microalgae alone, respectively, indicating that carbon fixation efficiency of microalgae applied in soil was improved with biochar and OF whilst the soil carbon capacity was promoted, the mechanism of which is illustrated through simulative experiments...
March 20, 2017: Biodegradation
Hunter W Schroer, Kathryn L Langenfeld, Xueshu Li, Hans-Joachim Lehmler, Craig L Just
Insensitive munitions explosives are new formulations that are less prone to unintended detonation compared to traditional explosives. While these formulations have safety benefits, the individual constituents, such as 2,4-dinitroanisole (DNAN), have an unknown ecosystem fate with potentially toxic impacts to flora and fauna exposed to DNAN and/or its metabolites. Fungi may be useful in remediation and have been shown to degrade traditional nitroaromatic explosives, such as 2,4,6-trinitrotoluene and 2,4-dinitrotoluene, that are structurally similar to DNAN...
February 2017: Biodegradation
Guang-Feng Yang, Li-Juan Feng, Cai-Rong Guo, Tian Xia, Xiang-Yang Xu, Liang Zhu
The initial formation of biofilm and the removal performance of pollutants in biological pretreatment process for polluted raw water were limited due to the oligotrophic niche in raw water. In this study, the feasibility of using pre-inoculation biofilm formed under nutrients enhanced condition for polluted raw water treatment was analyzed in nine batch reactors. Results showed that the pollutants removal performance of biofilm was improved under nutrients enhanced conditions. Ammonia oxidation rate (AOR) was exponentially increased with the increasing in NH4(+)-N levels, and organic matter removal rate (ORR) was positively related to the initial total organic carbon (TOC) concentration...
February 2017: Biodegradation
Alberto Ordaz, Mariana Sánchez, Rodrigo Rivera, Rafael Rojas, Alejandro Zepeda
A nitrifying consortium was kinetically, stoichiometrically and molecularly characterized via the in situ pulse respirometric method and pyrosequencing analysis before and after the addition of m-cresol (25 mg C L(-1)) in a sequencing batch reactor (SBR). Five important kinetic and stoichiometric parameters were determined: the maximum oxygen uptake rate, the maximum nitrification rate, the oxidation yield, the biomass growth yield, and the substrate affinity constant. An inhibitory effect was observed in the nitrification process with a recovery of this by up to eight SBR cycles after m-cresol was added to the system...
February 2017: Biodegradation
Kozet Yapsakli, Cigdem Kalkan Aktan, Bulent Mertoglu
For a successful nitrogen removal, Anammox process needs to be established in line with a stable partial nitritation pretreatment unit since wastewater influent is mostly unsuitable for direct treatment by Anammox. Partial nitritation is, however, a critical bottleneck for the nitrogen removal since it is often difficult to maintain the right proportions of NO2-N and NH4-N during long periods of time for Anammox process. This study investigated the potential of Anammox-zeolite biofilter to buffer inequalities in nitrite and ammonium nitrogen in the influent feed...
February 2017: Biodegradation
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