scholarly journals Performance Simulation and Assessment of an Appropriate Wastewater Treatment Technology in a Densely Populated Growing City in a Developing Country: A Case Study in Vientiane, Laos

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1012 ◽  
Author(s):  
Chanthephar Khattiyavong ◽  
Han Soo Lee
Keyword(s):  
Wastewater Treatment ◽  
Environmental Impacts ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Treatment System ◽  
Trickling Filter ◽  
Suitable Alternative ◽  
Wastewater Treatment System ◽  
Centralized Wastewater Treatment ◽  
Wastewater Treatment Systems

The fast-growing population in Vientiane, the capital of Laos, has resulted in increasing domestic wastewater generation, which directly impacts the urban water environment due to the lack of a suitable wastewater treatment system. This study aims to assess six wastewater treatment alternatives based on two technologies—trickling filter and activated sludge—used for on-site, decentralized, and centralized wastewater treatment systems to support decision-making for selecting the most suitable and practical alternative for wastewater treatment in Vientiane. To determine the most appropriate treatment system, the wastewater treatment process simulation with BioWin and the technique for order preference by similarity to ideal solution (TOPSIS) method are applied to assess the removal efficiencies for biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total suspended solids (TSS), as well as to rank the six wastewater treatment technologies based on the following four environmental criteria: (1) land requirement, (2) electricity use, (3) sludge production, and (4) CO2 emissions. The BioWin results illustrate that the capacity of each alternative is similar in terms of domestic wastewater treatment efficiency, while differing in terms of environmental impacts. In addition, the alternative ranking shows that a centralized wastewater treatment system with a trickling-filter process is more suitable than on-site and decentralized wastewater treatment systems based on their environmental impacts. This finding provides evidence for decision-makers to select a suitable alternative for wastewater treatment in order to promote access to safe sanitation and sustainable urban wastewater management in Vientiane, Laos.

scholarly journals Use of a duckweed pond for the domestic wastewater polishing in Ilha Solteira, SP, Brazil

2017 ◽  
Vol 28 (4) ◽  
pp. 477-489 ◽  
Author(s):  
Daiane Cristina de Oliveira Garcia ◽  
Liliane Lazzari Albertin ◽  
Tsunao Matsumoto
Keyword(s):  
Wastewater Treatment ◽  
Biomass Production ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Treatment System ◽  
Content Type ◽  
Stabilization Pond ◽  
Domestic Effluent ◽  
Duckweed Pond

Purpose The purpose of this paper is to evaluate the efficiency of a duckweed pond in the polishing of a stabilization pond effluent, as well as quantify its biomass production. Once an adequate destination is given to the produced biomass, the wastewater treatment plant can work in a sustainable and integrated way. Design/methodology/approach The duckweed pond consisted of a tank with volume 0.44 m3, operating in continuous flow with an outflow of 0.12 m3/day and hydraulic retention time of 3.8 days. Effluent samples were collected before and after the treatment, with analyzes made: daily-pH, dissolved oxygen and temperature; twice a week – total nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (COD); and weekly – total solids (TS) and Biochemical Oxygen Demand (BOD5). The duckweeds were collected each for seven days for its production quantification. Findings The highest efficiency of TN, TP, COD, BOD5 and TS removal were of 74.67, 66.18, 88.12, 91.14 and 48.9 percent, respectively. The highest biomass production rate was 10.33 g/m2/day in dry mass. Research limitations/implications There was great variation in biomass production, which may be related to the stabilization pond effluent conditions. The evaluation of the effluent composition, which will be treated with duckweeds, is recommended. Practical implications The evaluated treatment system obtained positive results for the reduction in the analyzed variables concentration, being an efficient technology and with operational simplicity for the domestic effluent polishing. Originality/value The motivation of this work was to bring a simple system of treatment and to give value to a domestic wastewater treatment system in a way that, at the same time the effluent polluter level is reduced and it is also possible to produce biomass during the treatment process.

scholarly journals Process performance and reuse potential of a decentralized wastewater treatment system

2019 ◽  
Vol 80 (11) ◽  
pp. 2079-2090 ◽  
Author(s):  
Rajiv Ranjan ◽  
Lokendra Kumar ◽  
P. C. Sabumon
Keyword(s):  
Wastewater Treatment ◽  
Growth Parameters ◽  
Oxygen Demand ◽  
Primary Treatment ◽  
Treatment System ◽  
Tagetes Erecta ◽  
Wastewater Treatment System ◽  
Decentralized Wastewater Treatment ◽  
Treated Effluent ◽  
Decentralized Wastewater Treatment System

Abstract The paper describes briefly the process performance and the reuse potential of a laboratory scale wastewater treatment system. The treatment involves enhanced primary treatment of Vellore Institute of Technology (VIT) campus sewage using ferric chloride as a coagulant, anaerobic digestion of coagulated organics, and biofilm aerobic process. The treated effluent after disinfection (using sunlight and chlorine) was used for irrigation of Tagetes erecta (marigold) plants and the plant growth parameters were evaluated for a life span of 3 months. In the primary treatment, an optimum ferric chloride dose of 30 mg/L could remove turbidity, chemical oxygen demand (COD), biochemical oxygen demand (BOD), and bacterial count (Escherichia coli) of 69%, 60%, 77%, and 55%, respectively. The coagulated organics could digest in a 25 L anaerobic reactor effectively with methane content in biogas varied between 50 and 60% and enhanced volatile suspended solids (VSS) reduction up to 70%. Sunlight based photo-oxidation followed chlorine disinfection saved 50% of the chlorine dose required for disinfection and treated effluent was fit for reuse. The results of growth parameters for Tagetes erecta plants indicate that anaerobically digested sludge is an excellent soil conditioner cum nutrient supplier. The results of this study exhibit a promising reuse potential of a decentralized wastewater treatment system and needs to be promoted for field scale applications.

scholarly journals Comparative analysis of the composition of bacterial communities from two constructed wetlands for municipal and swine wastewater treatment

2009 ◽  
Vol 8 (1) ◽  
pp. 147-157 ◽  
Author(s):  
Paula Arroyo ◽  
Gemma Ansola ◽  
Ivan Blanco ◽  
Patricia Molleda ◽  
Estanislao de Luis Calabuig ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Community Structure ◽  
Bacterial Community ◽  
Bacterial Communities ◽  
Bacterial Community Structure ◽  
Typha Latifolia ◽  
Treatment System ◽  
Swine Wastewater ◽  
Wastewater Treatment System ◽  
Wastewater Treatment Systems

This work provides information about bacterial community structure in natural wastewater treatment systems treating different types of wastewater. The diversity and composition of bacterial communities associated with the rhizosphere of Typha latifolia and Salix atrocinerea were studied and compared among two different natural wastewater treatment systems, using the direct sequencing of the 16S ribosomal RNA codifying genes. Phylogenetic affiliations of the bacteria detected allowed us to define the main groups present in these particular ecosystems. Moreover, bacterial community structure was studied through two diversity indices. Ten identified and five non-identified phyla were found in the samples; the phylum Proteobacteria was the predominant group in the four ecosystems. The results showed a bacterial community dominated by beta-proteobacteria and a lower diversity value in the swine wastewater treatment system. The municipal wastewater treatment system presented a high diverse community in both macrophytes (Typha latifolia and Salix atrocinerea), with gamma-proteobacteria and alpha-proteobacteria, respectively, as the most abundant groups.

Removal efficiency of the constructed wetland wastewater treatment system at Bainikeng, Shenzhen

1995 ◽  
Vol 32 (3) ◽  
pp. 31-40 ◽  
Author(s):  
Yang Yang ◽  
Zhencheng Xu ◽  
Kangping Hu ◽  
Junsan Wang ◽  
Guizhi Wang
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Constructed Wetland ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Design Flow ◽  
Treatment System ◽  
Wastewater Treatment System ◽  
Tennessee Valley ◽  
Wetland System

In this paper, three years study on a constructed wetland wastewater treatment system at Bainikeng, Shenzhen, is reviewed and summarized. The wetland system under study occupies an area of 8400m2, with a design flow of 3100 m3 per day. The study was conducted to understand removal efficiencies of constructed wetland systems for municipal wastewaters from small or medium scale towns in the sub-tropics. Such parameters as biological oxygen demand, chemical oxygen demand, suspended solids, total nitrogen, and total phosphorus in the influent and effluent of the wetland system are examined, and their removal rates are determined. It is shown that the system is very effective in removing organic pollutants and suspended solids and its removal efficiency is much similar to those of the constructed wetlands at Tennessee Valley Authority (TVA) (Choate et al., 1990) while better than those of conventional secondary biochemical treatments.

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