Constructed wetland treatment of source separated washing wastewater in rural areas of southern China

Author(s):  
Yahui Li ◽  
Shikun Zhu ◽  
Yu Zhang ◽  
Minghuan Lv ◽  
Jean Joël Roland Kinhoun ◽  
...  
2020 ◽  
Vol 3 (6) ◽  
pp. 8-11
Author(s):  
Bakaev Zh. N.

According to the authors, the prevalence of SOPR diseases is from 3 to 20%.In a study of 1573 residents of southern China in two age groups who use tobacco and alcohol, the incidence of SOPR was higher among men living in rural areas compared to urban residents. Among women aged 35-44 years, the incidence was higher in urban women, and in the 65-77-year-old group in rural women. In the course of studies in Brazil, among 335 patients older than 60 years, 646 diseases of the SOPR were identified. Similar results were obtained in the analysis of SOPR diseases in the Volgograd region of the Russian Federation


1995 ◽  
Vol 32 (3) ◽  
pp. 59-67 ◽  
Author(s):  
Kevin D. White

Constructed wetland technology is currently evolving into an acceptable, economically competitive alternative for many wastewater treatment applications. Although showing great promise for removing carbonaceous materials from wastewater, wetland systems have not been as successful at nitrification. This is primarily due to oxygen limitations. Nitrification does occur in conventional wetland treatment systems, but typically requires long hydraulic retention times. This paper describes a study that first evaluated the capability of subsurface flow constructed wetlands to treat a high strength seafood processor wastewater and then evaluated passive aeration configurations and effluent recirculation with respect to nitrogen treatment efficiency. The first stage of a 2-stage wetland treatment system exhibited a relatively short hydraulic retention time and was designed for BOD removal only. The second stage wetland employed an unsaturated inlet zone and effluent recirculation to enhance nitrification. Results indicate that organic loading, and thus BOD removal, in the first stage wetland is key to optimal nitrification. Passive aeration through an unsaturated inlet zone and recirculation achieved up to 65-70 per cent ammonia nitrogen removal at hydraulic retention times of about 3.5 days. Inlet zone configuration and effluent recirculation is shown to enhance the nitrogen removal capability of constructed wetland treatment systems.


2021 ◽  
Author(s):  
Vanitha Thammaiah ◽  
Manjunatha Hebbara ◽  
Manjunatha Mudukapla Virupakshappa

Abstract An experiment with different filterbeds and macrophytes was carried-out to study their phytoremediation capacity on the efficiency of domestic wastewater treatment through constructed wetland (CW) during November to March, 2017-18 at University of Agricultural Sciences, Dharwad campus, Karnataka, India. Twenty treatment combinations involving five types of filterbeds (FB-1: gravel, FB-2: gravel-sand-gravel, FB-3: gavel-sand-brick-gravel, FB-4: gravel-sand-charcoal-gravel and FB-5: gravel-sand-(charcoal+brick)-gravel) and four macrophytes (MP-1: Typha latifolia, MP-2: Brachiaria mutica, MP-3: Canna indica and MP-4: Phragmites sps.) were evaluated for treating domestic wastewater. After 120 days from start, across treatment combinations, water electrical conductivity (EC), total dissolved and suspended solids (TDS-TSS), biological oxygen demand (BOD), chemical oxygen demand (COD), sodium, sodium adsorption ratio (SAR), residual sodium carbonate (RSC), bicarbonates, total nitrogen-phosphorus-potassium (N-P-K) and boron (B) were reduced by more than 40 per cent due to wetland treatment. The system enhanced the mineralization of organic nitrogen to ammoniacal nitrogen (NH4+-N) and nitrate nitrogen (NO3-N) fractions. Among filterbeds, Type-5 caused higher reduction in pH, EC, BOD, COD and Organic-N while, Type-4 proved efficient in removing total solids and lowering pH in the sewage effluent. The Type-3 filterbed removed more suspended solids, potassium and ammoniacal nitrogen. Among the macrophytes, Brachiaria (paragrass) removed more nitrogen and potassium while, Phragmites removed more nitrogen, phosphorus and boron. The flexibility of implementation allows the CW to be adapted to different sites with different configurations, being suitable as main, secondary or tertiary treatment stage.


Author(s):  
Shalini Saxena

Wetlands, either constructed or natural, offer a cheaper and low-cost alternative technology for wastewater treatment. A constructed wetland system that is specifically engineered for water quality improvement as a primary purpose is termed as a ‘Constructed Wetland Treatment System’ (CWTS). In the past, many such systems were constructed to treat low volumes of wastewater loaded with easily degradable organic matter for isolated populations in urban areas. However, widespread demand for improved receiving water quality, and water reclamation and reuse, is currently the driving force for the implementation of CWTS all over the world. Recent concerns over wetland losses have generated a need for the creation of wetlands, which are intended to emulate the functions and values of natural wetlands that have been destroyed. Natural characteristics are applied to CWTS with emergent macrophyte stands that duplicate the physical, chemical and biological processes of natural wetland systems. The number of CWTS in use has very much increased in the past few years. The use of constructed wetlands is gaining rapid interest. Most of these systems cater for tertiary treatment from towns and cities. They are larger in size, usually using surface-flow system to remove low concentration of nutrient (N and P) and suspended solids. However, in some countries, these constructed wetland treatment systems are usually used to provide secondary treatment of domestic sewage for village populations. These constructed wetland systems have been seen as an economically attractive, energy-efficient way of providing high standards of wastewater treatment by the help of Phragmite karka plant. Typically, wetlands are constructed for one or more of four primary purposes: creation of habitat to compensate for natural wetlands converted for agriculture and urban development, water quality improvement, flood control, and production of food and fiber.


2011 ◽  
Vol 31 (2) ◽  
pp. 121-126 ◽  
Author(s):  
Zongpei Jiang ◽  
Xueqing Yu

BackgroundPeritoneal dialysis (PD) is developing rapidly in China, but because there are not enough well-trained PD doctors and nurses in more rural areas, this expansion is occurring mainly in larger cities. To address this imbalance, our center established a PD satellite center program across Guangdong Province, with the aim of extending the use and improving the quality of PD.MethodsSun Yat-sen University PD center is responsible for running the satellite program. The PD satellite centers are selected using specific criteria. The full-time PD physicians and nurses in the satellite centers accept a unified training program and treatment practices, and their clinical outcomes are carefully followed by our center.ResultsThe program began in January 2008, and there are now 12 PD centers from which 26 doctors and 32 nurses received PD training. Several hundred patients are now receiving PD through this program. The total number of PD patients treated by our center and the satellites increased to 1860 from 1010. The number treated in the satellite units increased to 1165 from 601. The annual dropout rate fell to 17.6% from 28.2%, and the average peritonitis incidence fell from 1 episode in 39.4 patient–months to 1 episode in 46.2 patient–months. The 1-year patient and technique survival rates increased to 84.2% from 82.0% and to 93% from 88.7% respectively.ConclusionsOur PD satellite center program is a good model for increasing the use and improving the quality of PD in rural areas. We plan to expand this program to other parts of southern China.


2012 ◽  
Vol 573-574 ◽  
pp. 511-515 ◽  
Author(s):  
Peng Huang ◽  
Yao Guang Guo ◽  
Xiao Yi Lou ◽  
Xue Wu Yuan ◽  
Shuang Jie Xu ◽  
...  

Due to the relatively unprogressive economic and social development of Songjiang rural areas of Shanghai city in China, the degree of rural domestic sewage treatment was relatively weak and hysteretic. The rural sewage treatment systems of Songjiang district were investigated through field survey. Finally, the systems of soil infiltration-constructed wetland and combinatorial biofilter, with obvious advantages, were proposed to popularize in Songjiang rural areas more suitably.


Desalination ◽  
2010 ◽  
Vol 250 (3) ◽  
pp. 915-920 ◽  
Author(s):  
Lie-yu Zhang ◽  
Lan Zhang ◽  
Yong-ding Liu ◽  
Yin-wu Shen ◽  
Hao Liu ◽  
...  

2007 ◽  
Vol 205 (3-4) ◽  
pp. 355-364 ◽  
Author(s):  
Volodymyr Tomenko ◽  
Sirajuddin Ahmed ◽  
Viktor Popov

2010 ◽  
Vol 62 (3) ◽  
pp. 603-614 ◽  
Author(s):  
G. D. Gikas ◽  
V. A. Tsihrintzis

A small-scale horizontal subsurface flow constructed wetland, located in North Greece, was designed and constructed to treat wastewater from a single-family residence. A three-year monitoring program was undertaken to evaluate the performance of this system. The monitoring campaigns were organized every 7 days. Water quality samples were collected at the inlet, at intermediate points (i.e. at the end of each treatment stage) and at the outlet of the system. Temperature, electrical conductivity, pH and DO were measured in-situ with the use of appropriate instruments at the same points of water sample collection. Water samples were analyzed for BOD, COD, TKN, ammonia, nitrate, nitrite, total phosphorus (TP), ortho-phosphate (OP), total suspended solids (TSS) and total coliforms (TC). Mean removal efficiencies for the monitoring period were: 86.5% for BOD, 84.6% for COD, 83.7% for TKN, 82.2% for ammonia, 63.1% for OP, 63.3% for TP, 79.3% for TSS and 99.9% for TC. Furthermore, based on statistical testing, TKN, ammonia and TP removal efficiencies showed dependence on temperature. The paper presents facility description, study details and monitoring results. The study shows that the use of constructed wetlands in wastewater treatment is a good option for single-family residences in rural areas.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Jianbo Li ◽  
Weihua Fan ◽  
Yueshan Zhou ◽  
Linmei Wu ◽  
Wei Liu ◽  
...  

Abstract Background Dental caries of deciduous teeth (Early Childhood Caries, ECC) has become a crucial oral health problem over the decades in China. The aim of this study was to examine the prevalence and severity of ECC among preschool children from Guangdong Province, Southern China. In addition, to assess the association of ECC with reported oral health-related behaviors. Methods A cross-sectional survey of 2592 participants was carried out in Guangdong Province by means of an equal-sized, stratified, multistage random sampling method during December 2015 and April 2016. The participants were divided into three groups according to their ages (3-, 4-, and 5-year-olds). Half of the participants were derived from urban areas, while the other from rural areas. According to the standard for clinical dentition examination of the WHO 2013 criteria, the presence of ECC was determined by the dmft (decayed-missing-filled tooth) index using a CPI (Community Periodontal Index) probe. A questionnaire about caries-related factors was completed by each of the participants’ parents or grandparents through a face-to-face and one-on-one interview. Then, t-test, Chi2 tests, One-Way ANOVA served for statistical analysis, and logistic regression analysis as well as covariance analysis were executed to identify potential associated factors for ECC. Results The prevalence (% dmft > 0) of ECC was 68.3 (95% CI: 66.5–70.1), the mean dmft was 4.36 (95% CI: 4.17–4.55), and the filled rate was 1.2%. In multivariable modeling, associated factors for both prevalence and mean dmft were older age, rural areas, consumption of sweets before sleep, dental visit history, low household income, and low parental education level. Initiating toothbrushing after 3 years of age and being exclusively/ predominantly breastfed indicated only the prevalence; being female and frequently consuming sweetened milk/powdered milk indicated only the mean dmft. Conclusions Preschool children in Guangdong Province, especially children from rural areas, experienced a significant amount of ECC. Associated factors for ECC included demographics, oral health measures, dietary factors, and socioeconomic factors. More attention should be given to prevention of ECC from early life. The construction of social support for oral health should be strengthened. Oral health education and promotion, especially of rural areas, should be intensified to reduce the inequality between urban and rural areas.


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