Treatment of wastewater containing linear alkylbenzene sulfonate by bacterial-microalgal biological turntable

Impacts of Linear Alkylbenzene (LABs) on ecosystems: Detection, fate and remediation

This review article provides a thorough examination of an interaction between linear alkylbenzenes (LABs) and ecosystems. The review covers various aspects of LABs' impact on ecosystems, focusing on detection and treatment strategies to mitigate ecological consequences. It delves into LABs' role as molecular markers for sewage pollution, their physicochemical properties contributing to persistence, and their effects on aquatic and terrestrial organisms, including disruptions to endocrine systems. The diverse sources of LABs, including domestic wastewater and industrial effluents, are explored, along with their ratios in different matrices for assessing contamination origins. Biodegradation pathways of LABs, both aerobic and anaerobic, are scrutinized, considering their interaction with microbes. Distribution patterns in aquatic environments are discussed, encompassing sediment, water, sewage, and soils. An investigation is conducted on the relationship between LABs and total organic carbon (TOC) as a means of evaluating sewage pollution. It is assessed how sewage treatment facilities (STPs) contribute to biodegradation.

The Effects of Low Concentrations and Long-Term Contamination by Sodium Dodecyl Sulfate on the Structure and Function of Bacterial Communities in the Lake-Terrestrial Ecotone

Due to the growing focus on daily hygiene practices, sodium dodecyl sulfate (SDS), a widely used surfactant, is increasingly found in domestic sewage and rainfall runoff. Upon entering the lake-terrestrial ecotone, SDS affects the composition, abundance, and functional capacity of soil bacterial communities due to its bacteriostatic properties. To investigate the effects of long-term discharge of sewage containing low concentrations of SDS on microorganisms in the lake-terrestrial ecotone, alterations in bacterial community structure, functional genes, and biomass were examined using a simulated continuous pollutant input. The results indicated the following: (1) The degradation rate of sodium dodecyl sulfate (SDS) by soil microorganisms in the lake-terrestrial ecotone under long-term and low concentrations of SDS stress ranged from 11 to 16 mg/kg·d. (2) The effects of low concentrations and long-term SDS stress on bacterial community structure and gene function in the lake-terrestrial ecotone differed significantly from those of short-term pollution. The damage to microbial-promoted material cycling in the lake-terrestrial ecotone was more severe; however, the proliferation of pathogenic bacteria remained continuously suppressed. (3) Soil bacteria in the lake-terrestrial ecotone responded to the stress of long-term and low concentrations of SDS primarily by enhancing chemotaxis and tolerance.

Efficient nitrogen removal by multi-stage A/O mud membrane composite process with segmented influent: Performance and microbial community structure

In this paper, a multi-stage A/O mud membrane composite process with segmented influent was constructed for the first time and compared with the traditional activated sludge process and the multi-stage A/O pure membrane process with segmented influent. The nitrogen removal efficiency of the process under different influencing factors was studied. Under the optimum conditions, the highest removal rate of ammonia nitrogen can reach 99%, and the average removal rate of total nitrogen was 80%. The removal rate of COD in effluent reached 93%. The relative abundance of Proteobacteria was the highest in the multi-stage A/O mud membrane composite reactor with segmented influent. The community diversity and richness of activated sludge and biofilm in aerobic pool were the highest. Dechloromonas, Flavobacterium and Rhodobacter were dominant bacteria, and they were aerobic denitrifying bacteria that significantly contributed to the removal rate of ammonia nitrogen.