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Schematic overview of the pilot-scale drinking water treatment process, including conventional treatment (coagulation-settlement process and rapid sand filtration), and advanced processes including ozonation, and biological activated carbon (BEAC) filtration
Source publication
A pilot-scale drinking water treatment process for Songhua River, including conventional treatment (coagulation-settlement and rapid sand filtration), ozonation, biological enhanced activated carbon (BEAC) filtration, and chlorination disinfection, was carried out in this study. To investigate the impact of ozonation and BEAC filtration on removing...
Citations
... Industrialization in China has led to various pollutants being discharged into water bodies (Wu et al. 2019), forming micropolluted source water and causing conventional drinking water treatment processes (coagulation, sedimentation, filtration, and disinfection) to no longer meet drinking water quality standards (Li et al. 2019a;Feng et al. 2020). Biological aerated filters (BAFs) were first developed in the late 1970s and early 1980s (Hasan et al. 2013b) based on conventional biological filters. ...
To improve the understanding of dissolved organic nitrogen (DON) variation characteristics in a biological aerated filter (BAF) used for drinking water treatment, this study investigated the effects of gas–water ratios (0, 0.5:1, 2:1, and 10:1), a controlling factor of BAF operation, on DON characteristics. The dissolved organic carbon (DOC) removal efficiency in the BAF was consistent with DON concentration and increased as the gas–water ratio increased to a certain point, above which the increase gradually decreased. The optimal gas–water ratio in this study was considered to be 2:1 from the perspective of DOC removal and DON reduction. Use of fluorescence regional integration (FRI) and parallel factor (PARAFAC) model to analyze the effects of the gas–water ratio on the spectral characteristics of DON revealed that humic acid-like substances were not sensitive to the gas–water ratio, while protein-like substances were more sensitive. Increasing the gas–water ratio was beneficial to the reduction of biodegradable DON. Correlation analysis showed that the results obtained using FRI were consistent with those obtained using the PARAFAC model under different gas–water ratios.
... The effects of other upstream treatments such as coagulation, ozonation or chlorination on bacterial growth and density have to be considered, as these treatments can impact biofilm development. For example, residual chlorine in the influent water to a pilot-scale BAC unit reduced the bacterial attachment on its surface, while a pre-ozonation process before BAC treatment improved the biological activity of the biofilm for contaminant degradation in many cases (Simpson, 2008;Lohwacharin et al., 2015;Nemani et al., 2018;Ibn Abdul Hamid et al., 2019;Li et al., 2019). These aspects should be considered during design of BEB filters for industrial/municipal applications. ...
... The presence of toxic and carcinogenic compounds such as Polycyclic Aromatic Hydrocarbons (PAH) and Volatile Organic Compounds (VOCs) that form during pyrolysis and deposit on biochar surface/pores is undesirable (Buss et al., 2015;Li et al., 2019). However, production of clean biochar is feasible and can be achieved by tuning a few key process parameters such as peak temperature, feedstock type, residence time and carrier gas flow rate (Manyà, 2019;Manya, 2012;Buss et al., 2016). ...
Cost-effective, efficient, and sustainable water treatment solutions utilising existing materials and technology will make it easier for low and middle-income countries to adopt them, improving public health. The ability of biochar to mediate and support microbial degradation of contaminants, combined with its carbon-sequestration potential, has attracted attention in recent years. Biochar is a possible candidate for use in cost-effective and sustainable biological water treatment, especially in agrarian economies with easy access to abundant biomass in the form of crop residues and organic wastes. This review evaluates the scope, potential benefits (economic and environmental) and challenges of sustainable biological water treatment using ‘Biologically-Enhanced Biochar’ or BEB. We discuss the various processes occurring in BEB systems and demonstrate the urgent need to investigate microbial degradation mechanisms. We highlight the need to correlate biochar properties to biofilm development, which can eventually determine process efficiency. We also demonstrate the various opportunities in adopting BEB as a cheaper and more viable alternative in Low and Middle Income Countries and compare it to the current benchmark, ‘Biological Activated Carbon’. We focus on the recent advances in the areas of data science, mathematical modelling and molecular biology to systematically and sustainably design BEB filters, unlike the largely empirical design approaches seen in water treatment. ‘Sequential biochar systems’ are introduced as specially designed end-of-life techniques to lower the environmental impact of BEB filters and examples of their integration into biological water treatment that can fulfil zero waste criteria for BEBs are given.
Distributions of halogenated disinfection byproducts (DBPs) in a two-source water distribution system (WDS) with enhanced chlorination were investigated. The WDS was divided into different sub-service areas based on different electrical conductivity of two water sources. Results clearly show that the principal halogenated DBPs were trihalomethanes (THMs) (5.06-82.69 μg/L), varying within the concentration range as 2-5 times as the levels of haloacetic acids (HAAs) (1.41-61.48 μg/L) and haloacetonitriles (HANs) (0.21-15.13 μg/L). Different water sources, treatment trains, and enhanced chlorination within the WDS had significant effects on seasonal and spatial variations of the DBP distributions over water conveyance. THM and HAA formation followed the sequence of summer > autumn > winter > spring. On the other hand, the DBP spatial distributions were visualized using the ArcGIS enabled Inverse distance weighting technique. The superposition of different DBP spatial distributions allowed for the identification of the high-risk THMs and HAAs areas based on the average values of THMs (27.49 μg/L) and HAAs (14.06 μg/L). Beyond the comprehensive analyses of DBP distribution in a municipal WDS, the project proposed and validated an innovative methodology to locate the DBP high-risk areas and to reveal the effects of different factors on DBPs distribution in a two-source WDS.
