Studies on influence of process parameters on simultaneous biodegradation of atrazine and nutrients in aquatic environments by a membrane photobioreactor

Abstract

A Lab scale algal-bacterial membrane photobioreactor (MPBR) was designed and operated under 12-h light and 12-h dark conditions with a light intensity of 8000lx, in order to investigate the effects of initial concentrations of atrazine, carbon concentration, and hydraulic retention time on the ability of this photobioreactor in simultaneous removal of atrazine and nutrients in the continuous mode. The removal efficiencies of atrazine (ATZ), chemical oxygen demand (COD), phosphorus (PO-P) and nitrogen (NOx) in optimum condition was more than 95%, 99%, 98% and 97% when the maximum removal rates were 9.5 × 10, 99.231, 11.773 and 7.762mg/L-day, respectively. Results showed that the quality of the effluent was reduced by the increase of atrazine concentration. The outcomes on the hydraulic and toxic shocks indicated that the system has a relatively good resistance to the shocks and can return to the stable conditions. Microalgae showed a great deal of interest and capability in cultivating and attaching to the surface of the membrane and bioreactor, and the total biomass accumulated in the system was greater than 6g/L. The kinetic coefficients of atrazine removal were also studied using various kinetic models. The maximum atrazine removal rate was determined by the modified Stover-Kincannon model. The results approved the ability of the MPBR reactor in wastewater treatment and microalgae cultivation and growth. The decline of atrazine concentration in this system could be attributed to the algal-bacterial symbiosis and co-metabolism process. Accordingly, the MPBR reactor is a practical, simple, economical and therefore suitable process for simultaneous biodegradation of chlorinated organic compounds and nutrients removal from aquatic environments.

Effects of sulphur amino acids on the size and structure of microbial communities of aerobic granular sludge bioreactors

“…According to these reasons and to ensure water safety, it is crucial to design and develop integrated WW treatment systems that tackle environmental, social and economic concerns (Luqman and Al-Ansari, 2021 ; Derakhshan et al 2018a , b ). In this regard, different compact and efficient biological WW treatment technologies have been designed during the past years such as membrane photobioreactors or aerobic granular sludge (AGS) (Derakhshan et al 2018a , b ) technology.…”

“…According to these reasons and to ensure water safety, it is crucial to design and develop integrated WW treatment systems that tackle environmental, social and economic concerns (Luqman and Al-Ansari, 2021 ; Derakhshan et al 2018a , b ). In this regard, different compact and efficient biological WW treatment technologies have been designed during the past years such as membrane photobioreactors or aerobic granular sludge (AGS) (Derakhshan et al 2018a , b ) technology. The AGS system has turned into a promising tool over other biological methods due to different advantages as follows: excellent settling properties, high biomass retention, low production of sludge excess, removal nutrients and carbon in the same chamber and capacity to operate at shorter hydraulic retention times (Adav et al 2008 ; Nancharaiah and Reddy, 2018 ; Rosa-Masegosa et al 2021 ).…”

Atrazine Removal from Municipal Wastewater Using a Membrane Bioreactor

“…In recent studies, Derakhshan et al [16,17] obtained very high levels of atrazine removal using a membrane photobioreactor and a moving bed biofilm reactor. In the former case, atrazine removal was due to a symbiotic relationship between algae and bacteria that led to co-metabolism.…”

Bacterial Biodegradation of 4-Monohalogenated Diphenyl Ethers in One-Substrate and Co-Metabolic Systems

“…In addition, an easier accessible carbon source can contribute to the additional multiplication of microorganisms, so that more of them can participate in the persistent pollutants' biodegradation [16]. The beneficial effect of co-metabolism has been observed in the biodegradation of xylenes [17], atrazine [18], and several pharmaceuticals [19].…”