Wastewater treatment by algal turf scrubbing

2001 ◽  
Vol 44 (11-12) ◽  
pp. 427-433 ◽  
Author(s):  
R.L. Craggs
Keyword(s):  
Wastewater Treatment ◽  
Heterotrophic Bacteria ◽  
Treated Wastewater ◽  
Algal Turf ◽  
Agricultural Drainage ◽  
Treatment Processes ◽  
Periphyton Biomass ◽  
Algal Photosynthesis ◽  
Bacteria And Fungi ◽  
Shallow Stream

Algal turf scrubbing (ATS) is a novel wetland technology that has been designed and engineered to promote natural wastewater treatment processes. Algal turf scrubbing improves water quality by passing a shallow stream of wastewater over the surface of a gently sloped floway. The floway is colonised by a natural heterogeneous assemblage of periphyton consisting of cyanobacteria, filamentous algae and epiphytic diatoms together with aerobic bacteria and fungi. Algal photosynthesis provides oxygen for aerobic breakdown of wastewater by heterotrophic bacteria. Pollutants are extracted from the wastewater by several processes including assimilation, adsorption, filtration and precipitation. The algal turf is harvested periodically to remove the accumulated periphyton biomass and associated pollutants from the system. This paper will present results from a demonstration ATS facility in Patterson, California which was used to polish secondarily treated wastewater. The design and operational factors that influence the treatment performance of ATS systems is discussed. Results indicate the potential of the ATS for nutrient removal from secondarily treated wastewater and agricultural drainage waters.

Occurrence and fate of relevant substances in wastewater treatment plants regarding Water Framework Directive and future legislations

2012 ◽  
Vol 65 (7) ◽  
pp. 1179-1189 ◽  
Author(s):  
S. Martin Ruel ◽  
J.-M. Choubert ◽  
H. Budzinski ◽  
C. Miège ◽  
M. Esperanza ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Water Framework Directive ◽  
Municipal Wastewater ◽  
River Flow ◽  
Wastewater Treatment Plants ◽  
Quality Standard ◽  
Treated Wastewater ◽  
Municipal Wastewater Treatment ◽  
Conventional Activated Sludge ◽  
Treatment Processes

The next challenge of wastewater treatment is to reliably remove micropollutants at the microgram per litre range. During the present work more than 100 substances were analysed through on-site mass balances over 19 municipal wastewater treatment lines. The most relevant substances according to their occurrence in raw wastewater, in treated wastewater and in sludge were identified, and their fate in wastewater treatment processes was assessed. About half of priority substances of WFD were found at concentrations higher than 0.1 μg/L in wastewater. For 26 substances, potential non-compliance with Environmental Quality Standard of Water Framework Directive has been identified in treated wastewater, depending on river flow. Main concerns are for Cd, DEHP, diuron, alkylphenols, and chloroform. Emerging substances of particular concern are by-products, organic chemicals (e.g. triclosan, benzothiazole) and pharmaceuticals (e.g. ketoprofen, diclofenac, sulfamethoxazole, carbamazepine). About 80% of the load of micropollutants was removed by conventional activated sludge plants, but about two-thirds of removed substances were mainly transferred to sludge.

A Review of the Occurrence of Pharmaceutical Compounds as Emerging Contaminants in Treated Wastewater and Aquatic Environments

2021 ◽  
Vol 18 ◽  
Author(s):  
Rahul Silori ◽  
Syed Mohammad Tauseef
Keyword(s):  
Wastewater Treatment ◽  
Emerging Contaminants ◽  
Wastewater Treatment Plants ◽  
Pharmaceutical Compounds ◽  
Treated Wastewater ◽  
Aquatic Environments ◽  
Aquatic Life ◽  
Adverse Health Effects ◽  
Treatment Processes ◽  
Comprehensive Information

: In recent years, pharmaceutical compounds have emerged as potential contaminants in the aquatic matrices of the environment. High production, consumption, and limited removal through conventional treatment processes/wastewater treatment plants (WWTPs) are the major causes for the occurrence of pharmaceutical compounds in wastewater and aquatic environments worldwide. A number of studies report adverse health effects and risks to aquatic life and the ecosystem because of the presence of pharmaceutical compounds in the aquatic environment. This paper provides a state-of-the-art review of the occurrence of pharmaceutical compounds in treated wastewater from various WWTPs, surface water and groundwater bodies. Additionally, this review provides comprehensive information and pointers for research in wastewater treatment and waterbodies management.

Aerobic Bio-oxidation with Ozonation for Recalcitrant Wastewater Treatment

2008 ◽  
Vol 11 (2) ◽  
Author(s):  
Inna Kamenev ◽  
Andres Viiroja ◽  
Juha Kallas
Keyword(s):  
Wastewater Treatment ◽  
Oil Shale ◽  
Chemical Oxidation ◽  
Treated Wastewater ◽  
Circulation System ◽  
Direct Introduction ◽  
Combined Process ◽  
Oxidation Processes ◽  
Purification Efficiency ◽  
Treatment Processes

AbstractThe aim of the present research was to find a combination of biological and chemical oxidation processes that improves the purification efficiency of recalcitrant wastewater treatment at reduced ozone consumption. The following wastewater treatment processes were experimentally studied: conventional aerobic biooxidation, post-ozonation of biologically treated wastewater, a combined process - aerobic bio-oxidation with ozonation in a re-circulation system - and aerobic bio-oxidation with direct introduction of ozone-containing water into a bioreactor. A synthetic landfill leachate corresponding in its composition to leachate of young landfills, thermo-mechanical pulping water, and phenolic effluent from the Estonian oil shale industry were used as wastewaters. It was established that compared with conventional aerobic bio-oxidation, the combined process enables an improvement in purification efficiency even at relatively low ozone doses (10 to 60 mgO

Dewatering as a non-toxic control of nuisance midge larvae in algal wastewater treatment floways

2014 ◽  
Vol 71 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Troy A. Keller ◽  
Emily M. Husted
Keyword(s):  
Wastewater Treatment ◽  
Chlorophyll A ◽  
Operating Costs ◽  
Treated Wastewater ◽  
Short Term ◽  
Algal Communities ◽  
Direct Exposure ◽  
High Nutrient ◽  
Periphyton Biomass ◽  
Algal Productivity

Attached-algae floways have tremendous potential for use in wastewater treatment because natural algal communities show high nutrient removal efficiencies, have low operating costs, and are easy to maintain. Algal wastewater floways may also serve as a sustainable option for producing renewable energy because algae grow rapidly, are easily harvested, and can serve as a source of biomass for biofuel. However, pests such as chironomids (Diptera) colonize open channel periphyton floways and their larvae damage the biofilms. While pesticides can control midge larvae, little information is known about alternative, non-toxic controls. This study examined the effectiveness of periodic, short-term dewatering (4 hours every 9 days) on midge abundance and periphyton growth in 16 recirculating, outdoor floways (3 m long, 0.1 m wide). We compared midge abundance and algal accumulation (chlorophyll a, b, c, and pheophytin) among control (n = 8) and dewatered (n = 8) floways filled with secondarily treated wastewater (27 days, 10 hours of daylight). Dewatered flumes had 42% fewer midges and 28–49% lower algal productivity (as measured by chlorophyll a, b, c, and pheophytin pigments). Chlorophyll a production rates averaged (±1 SD) 0.5 ± 0.2 μg/cm2/day in control floways compared to 0.3 ± 0.1 μg/cm2/day dewatered floways. Short-term dewatering effectively reduced midges but also damaged periphyton. To maximize the recovery of periphyton biomass, operators should harvest periphyton from floways during dewatering events before periphyton is damaged by desiccation or direct exposure to sunlight.

scholarly journals Membrane Technologies in Wastewater Treatment: A Review

Membranes ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 89 ◽  
Author(s):  
Elorm Obotey Ezugbe ◽  
Sudesh Rathilal
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Membrane Technology ◽  
Treated Wastewater ◽  
Future Research ◽  
Water Shortages ◽  
Advantages And Disadvantages ◽  
Treatment Processes ◽  
Membrane Technologies ◽  
Over Exploitation

In the face of water shortages, the world seeks to explore all available options in reducing the over exploitation of limited freshwater resources. One of the surest available water resources is wastewater. As the population grows, industrial, agricultural, and domestic activities increase accordingly in order to cater for the voluminous needs of man. These activities produce large volumes of wastewater from which water can be reclaimed to serve many purposes. Over the years, conventional wastewater treatment processes have succeeded to some extent in treating effluents for discharge purposes. However, improvements in wastewater treatment processes are necessary in order to make treated wastewater re-usable for industrial, agricultural, and domestic purposes. Membrane technology has emerged as a favorite choice for reclaiming water from different wastewater streams for re-use. This review looks at the trending membrane technologies in wastewater treatment, their advantages and disadvantages. It also discusses membrane fouling, membrane cleaning, and membrane modules. Finally, recommendations for future research pertaining to the application of membrane technology in wastewater treatment are made.

scholarly journals ABACO: A New Model of Microalgae-Bacteria Consortia for Biological Treatment of Wastewaters

2021 ◽  
Vol 11 (3) ◽  
pp. 998 ◽  
Author(s):  
Ana Sánchez-Zurano ◽  
Enrique Rodríguez-Miranda ◽  
José Luis Guzmán ◽  
Francisco Gabriel Acién-Fernández ◽  
José M. Fernández-Sevilla ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Heterotrophic Bacteria ◽  
Nitrifying Bacteria ◽  
Endogenous Respiration ◽  
Model Parameters ◽  
Pig Slurry ◽  
Microalgal Biomass ◽  
Treatment Processes ◽  
Nutrient Consumption ◽  
Different Populations

Microalgae-bacteria consortia have been proposed as alternatives to conventional biological processes to treat different types of wastewaters, including animal slurry. In this work, a microalgae-bacteria consortia (ABACO) model for wastewater treatment is proposed, it being calibrated and validated using pig slurry. The model includes the most relevant features of microalgae, such as light dependence, endogenous respiration, and growth and nutrient consumption as a function of nutrient availability (especially inorganic carbon), in addition to the already reported features of heterotrophic and nitrifying bacteria. The interrelation between the different populations is also included in the model, in addition to the simultaneous release and consumption of the most relevant compounds, such as oxygen and carbon dioxide. The implementation of the model has been performed in MATLAB software; the calibration of model parameters was carried out using genetic algorithms. The ABACO model allows one to simulate the dynamics of different components in the system, and the relative proportions of microalgae, heterotrophic bacteria, and nitrifying bacteria. The percentage of each microbial population obtained with the model was confirmed by respirometric techniques. The proposed model is a powerful tool for the development of microalgae-related wastewater treatment processes, both to maximize the production of microalgal biomass and to optimize the wastewater treatment capacity.

scholarly journals Prevalence of common enteric viruses in municipal wastewater treatment plants and their health risks arising from wastewater reuse

2021 ◽  
Author(s):  
Peng Liu ◽  
Zihan Li ◽  
Zifan Che ◽  
Hu Xinran ◽  
Ming Ying ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Health Risks ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Wastewater Reuse ◽  
Enteric Viruses ◽  
Treated Wastewater ◽  
Tertiary Treatment ◽  
Treatment Processes ◽  
Raw Wastewater

Abstract Enteric viruses are known to be prevalent in municipal wastewater, but information on the health risks arising from wastewater reuse is limited. This study quantified six common enteric viruses in raw wastewater and determined the effectiveness of different secondary and tertiary treatment processes at reducing their abundances in three full-scale wastewater treatment plants in China. In the raw wastewater, polyomavirus BK and norovirus GII (Nov GII) exhibited the highest abundance among the detected DNA and RNA viruses, respectively, with concentrations >5 log10 copies/L. Viruses in the raw wastewater were mainly removed by the secondary treatment processes, with log reduction values ranging from 1 to 2. The tertiary treatment processes of both chlorination and ultraviolet irradiation facilitated the additional reduction of viruses. The quantitative microbial risk assessment was applied to estimate the health risks of adenovirus (Adv) and Nov GII when reusing the treated wastewater for irrigation of public green spaces and crops. Estimated disabled-adjusted life-years of Adv and Nov GII for both reuses were higher than the risk threshold (10−6) required by the WHO in the actual scenarios. More effective treatment technologies should be implemented to remove viruses for safe reuse of the treated wastewater.

Semi-quantitative analysis of a specific database on priority and emerging substances in wastewater and sludge

2008 ◽  
Vol 57 (12) ◽  
pp. 1935-1944 ◽  
Author(s):  
S. Martin Ruel ◽  
J. M. Choubert ◽  
P. Ginestet ◽  
M. Coquery
Keyword(s):  
Wastewater Treatment ◽  
Quantitative Analysis ◽  
Wastewater Treatment Plants ◽  
Treated Wastewater ◽  
Quality Of Data ◽  
Screening Programs ◽  
Conventional Activated Sludge ◽  
Treatment Processes ◽  
Few Data ◽  
Emerging Substances

The Water Framework Directive (WFD) has drawn attention to a series of metals and organic compounds because of their demonstrated or potential harmfulness for aquatic environments. The aim of our work was to build and to process a “practical” database focused on the role of wastewater treatment plants for the removal of the 37 priority compounds that have to be reduced or stopped by 2015, and of 34 additional relevant contaminants. About 11,000 concentration values in raw and treated wastewater and sludge, from more than 100 peer-reviewed articles and six French national screening programs, were integrated. A systematic approach showed the global low quality of data for most of the compounds, with missing information about the treatment process, sampling and analysis, leading to 10% of the data available for removal efficiency calculations. A semi-quantitative analysis allowed the identification of 20 priority and 10 additional relevant substances more frequently quantified at significant concentrations in raw wastewater and treated wastewater. Conventional activated sludge was able to remove more than 70% of half of the studied compounds, leaving only 10% of them with less than 50% removal. Physical–chemical treatments appeared to be about 30% less efficient than biological treatments. In addition, very few data are available concerning some compounds and some processes, especially sludge treatment and tertiary wastewater treatment processes. Therefore, complementary on-site measurements and modeling are required to propose adapted solutions for the treatment of priority and emerging substances in wastewater treatment plants.

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