scholarly journals Measuring the Performance of Wastewater Treatment in China

2019 ◽  
Vol 9 (1) ◽  
pp. 153 ◽  
Author(s):  
Ying Feng ◽  
Yung-ho Chiu ◽  
Fan-peng Liu

When a developing country is undergoing a rapid growth period, agricultural wastewater, domestic wastewater, industrial wastewater, and organic matter content in chemical oxygen demand (COD) usually increase in great amounts, causing environmental pollution. Thus, this paper proposes a summary of factors to assess the performance of wastewater discharge costs. Total fixed assets, population growth, and wastewater treatment expenses in various regions of China were used as input factors, while gross regional product, discharged wastewater, and discharged COD were used as output factors. We employed the directional distance function (DDF) method to compare 31 regions of China between 2011 and 2015. The results showed that areas with leading economic development and areas with a small population and vast natural land have good wastewater treatment efficiency. In the past five years, economic development and wastewater treatment expense efficiency in Chongqing have been improving, such that by the end of 2015, this region efficiency was approaching frontier efficiency. We also found that the efficiency of wastewater treatment expense in many areas often falls below 0.6, which is still very low. There is, thus, a large gap between the regions and the leading frontier regions, meaning that the efficiency of wastewater treatment expense needs to be improved.

2021 ◽  
Vol 3 (2) ◽  
pp. 130-140
Author(s):  
Maria Diana Puiu ◽  

The food industry wastewater is known to present a high organic matter content, due to specific raw materials and processing activities. Even if these compounds are not directly toxic to the environment, high concentrations in effluents could represent a source of pollution as discharges of high biological oxygen demand may impact receiving river's ecosystems. Identifying the main organic contaminants in wastewater samples represents the first step in establishing the optimum treatment method. The sample analysis for the non-target compounds through the GC-MS technique highlights, along with other analytical parameters, the efficiency of the main physical and biological treatment steps of the middle-size Wastewater Treatment Plant (WWTP). Long-chain fatty acids and their esters were the main abundant classes of non-target identified compounds. The highest intensity detection signal was reached by n-hexadecanoic acid or palmitic acid, a component of palm oil, after the physical treatment processes with dissolved air flotation, and by 1-octadecanol after biological treatment.


2021 ◽  
Vol 941 (1) ◽  
pp. 012001
Author(s):  
Basamykina Alena ◽  
Kurkina Ekaterina ◽  
Kameristaya Maria

Abstract Biological treatment methods are used to remove organic and some inorganic substances from wastewater using the simplest organisms that use these substances for nutrition, breaking them down using cellular processes. The article deals with the aerobic, anaerobic and anoxic stages of biological wastewater treatment. Their differences are explained and the best way to use biological processes is analyzed according to the type of industry/production. At wastewater treatment plants, anaerobic treatment is often used at first to remove a significant part of organic substances from wastewater before sending them for further aerobic treatment. Aerobic treatment is effective for various types of wastewater, especially with lower biochemical oxygen demand (BOD) and chemical oxygen demand (COD). A comparative analysis of wastewater composition from food, oil and gas processing, pharmaceutical and pulp and paper industries was carried out. In the presence of organic compounds, the technology is chosen depending on the total organic matter content or the total COD content, which characterizes the total organic matter in water. A combination of anaerobic and aerobic methods is possible, if a discharge into the sewer system or into water bodies is required. The grounds for the application of biological wastewater treatment of these industries are given.


2021 ◽  
Author(s):  
Waldir Nagel Schirmer ◽  
Erivelton César Stroparo ◽  
Marlon André Capanema ◽  
Douglas Luiz Mazur ◽  
José Fernando Thomé Jucá ◽  
...  

Abstract Biofilters have been recognized as key technology in the mitigation of greenhouse gases (GHG) emitted by landfills. This study aimed to evaluate the methane (an important GHG) oxidation efficiencies of two experimental biofilters at the municipal landfill of Guarapuava (Brazil) under normal conditions (control column), just using landfill cover soil with low organic matter content, and improved, exploiting dried scum from municipal wastewater treatment plant (SWWTP) mixed with the cover soil (enriched column, with a high organic matter content). The influence of parameters such as the methane inlet loading rates (22 and 44 gCH4.m− 2.d− 1), temperatures, methane concentration in the raw biogas, carbon/nitrogen ratio and moisture content of the packing materials on the oxidation of methane was also evaluated during 25 campaigns. The campaigns with the lowest methane loading rates applied to the biofilters showed the best methane oxidation efficiencies (98.4% and 89.5% in the enriched and control columns, respectively) as compared to campaigns with a higher load (92.6% and 82.6% in the enriched and control columns, respectively). In addition to the loading rates, the methane oxidation efficiencies were highly influenced by the organic matter content and C/N ratio of the packing materials evaluated.


2018 ◽  
Vol 13 (3) ◽  
pp. 457-464
Author(s):  
PRIYANAND AGALE ◽  
PARAG SADGIR

Rural wastewater treatment is mostly ignored in developing and undeveloped countries. The most important barrier for addressing to this problem is cost of treatment and simplified technology. Aerobic Brickbat Grit Sand (ABGS) purifier consists of four stages. Wastewater flows gravitationally through partition walls in zigzag pattern with brick bats filter; Pebble sand filter and charcoal and grit filter which facilitate removal of contaminants from domestic wastewater. In the present study, experimental model for domestic wastewater treatment was setup in the Environmental Engineering laboratory at Government College of Engineering Aurangabad, Maharashtra. Physiochemical analysis was done in August and September of 2016 the percentage removal of contaminants results shows Biological Oxygen Demand (BOD) 92% - 87%, Chemical Oxygen Demand (COD) 93 - 89%, Total Suspended Solids( TSS) 80 - 78% and Turbidity 95 - 85%. The process is considered eco-friendly and easy to install technology for domestic wastewater treatment with use of locally available material. ABGS purifier is decentralized approach of domestic wastewater treatment. Hence ABGS as an alternative solution to tackle over the problem of rural wastewater treatment.


2017 ◽  
Vol 28 (4) ◽  
pp. 477-489 ◽  
Author(s):  
Daiane Cristina de Oliveira Garcia ◽  
Liliane Lazzari Albertin ◽  
Tsunao Matsumoto

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.


Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 231 ◽  
Author(s):  
Renata Xavier Alberico Freitas ◽  
Lara Aguiar Borges ◽  
Handray Fernandes de Souza ◽  
Fernando Colen ◽  
Alex Sander Rodrigues Cangussu ◽  
...  

The generation of large volumes of waste by industrial processes has become an object of study because of the necessity to characterize the composition of residues in order to suggest appropriate treatments and to minimize adverse environmental impacts. We performed analyses of total fixed and volatile solids, moisture, and chemical oxygen demand (COD). We found high organic matter content. We also measured physicochemical characteristics, including corrosivity, reactivity, and toxicity. Sewage sludge showed levels of chloride and sodium above the maximum allowed limits. These data suggest the potential for anaerobic digestion as a treatment option for sewage sludge and for its use as a biofertilizer.


2013 ◽  
Vol 68 (10) ◽  
pp. 2264-2270 ◽  
Author(s):  
M. Zapater-Pereyra ◽  
F. van Dien ◽  
J. J. A. van Bruggen ◽  
P. N. L. Lens

A constructed wetroof (CWR) is defined in this study as the combination of a green roof and a constructed wetland: a shallow wastewater treatment system placed on the roof of a building. The foremost challenge of such CWRs, and the main aim of this investigation, is the selection of an appropriate matrix capable of assuring the required hydraulic retention time, the long-term stability and the roof load-bearing capacity. Six substrata were subjected to water dynamics and destructive tests in two testing-tables. Among all the materials tested, the substratum configuration composed of sand, light expanded clay aggregates, biodegradable polylactic acid beads together with stabilization plates and a turf mat is capable of retaining the water for approximately 3.8 days and of providing stability (stabilization plates) and an immediate protection (turf mat) to the system. Based on those results, a full-scale CWR was built, which did not show any physical deterioration after 1 year of operation. Preliminary wastewater treatment results on the full-scale CWR suggest that it can highly remove main wastewater pollutants (e.g. chemical oxygen demand, PO43−-P and NH4+-N). The results of these tests and practical design considerations of the CWR are discussed in this paper.


2002 ◽  
Vol 46 (9) ◽  
pp. 263-270 ◽  
Author(s):  
P. Dama ◽  
J. Bell ◽  
K.M. Foxon ◽  
C.J. Brouckaert ◽  
T. Huang ◽  
...  

Large proportions of South Africans live in areas with inadequate sanitation and a poor infrastructure for waterborne sanitation. Service providers are looking for alternative wastewater treatment options. The anaerobic baffled reactor is being considered as a decentralised sanitation option in these areas. A 3,200 L reactor was built and is currently being evaluated at a wastewater treatment works. The reactor was built based on experiences gained from working with a laboratory reactor (10 L) and predicted flow patterns observed on a computational fluid dynamics model. The design and construction of the reactor will be discussed in this paper. The feed to the reactor consists of screen degritted sewage and the flow to the reactor is maintained by means of a programmable logic controller. The pilot-plant layout is discussed in this paper. Samples are analysed for chemical oxygen demand, pH, alkalinity, ammonia, phosphorus, solids and ash content. Reductions of between 70 and 80% are obtained for COD and the pH values for the effluent samples are within the discharge limits.


2020 ◽  
Author(s):  
Silambarasi Mooralitharan ◽  
Zarimah Hanafiah ◽  
Teh Sabariah Abd Manan ◽  
Hassimi Hasan ◽  
Henritte Jensen ◽  
...  

Abstract The fungi-based technology, wild-Serbian Ganoderma lucidum (WSGL) as myco-alternative to existing conventional microbial-based wastewater treatment is introduced in this study as a potential alternative treatment. The mycoremediation is highly persistent for its capability to oxidatively breakdown pollutant substrates and widely researched for its medicinal properties. Utilizing the non-hazardous properties and high degradation performance of WSGL, this research aims to find optimum conditions and model the mycoremediation treatment design for Chemical Oxygen Demand (COD) and Ammonia Nitrogen (AN) removal in domestic wastewater via response surface methodology (RSM). Combined process variables were temperature (⁰C) (Model 1) and the volume of mycelial pellets (%) (Model 2) against treatment time (hour). Response variables for these two sets of central composite design (CCD) were the removal efficiencies of COD (%) and AN (%). The regression line fitted well with the data with R2 values of 0.9840 (Model 1-COD), 0.9477 (Model 1-AN), 0.9988 (Model 2-COD) and 0.9990 (Model 2-AN). The lack of fit test gives the highest value of Sum of Squares equal to 9494.91 (Model 1- COD), 9701.68 (Model 1-AN), 23786.55 (Model 2-COD) and 13357.02 (Model 2-AN), with probability F values less than 0.05 showing significant models. The optimum conditions were established corresponding to the percentage of COD and AN removal obtained were 95.1% and 96.3%, accordingly at the optimum temperature 25°C at the treatment time of 24 h, meanwhile 0.25% of mycelial pellet with 76.0% and 78.4% COD and AN removal, respectively. The high performance achieved demonstrates that the mycoremediation of G. lucidum is highly potential as part of the wastewater treatment system in treating domestic wastewater of high organic loadings.


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