Wastewater Treatment In Rural Areas Research Articles

Performance of Equisetum spp and Zantedeschia aethiopica on the evaluation of artificial wetlands as an alternative for wastewater treatment in rural areas of the Ecuadorian Andes

Constructed wetlands have been used worldwide as an alternative for wastewater treatment. The purpose of this study was to evaluate two constructed wetlands for wastewater treatment using two different species of macrophyte in order to reduce pollution levels in the Curiquingue Creek belonging to the Baños parish in Cuenca, Ecuador. A pilot plant was constructed using Equisetum spp and Zantedeschia aethiopica with a constant flow of 0.32m3d−1. Each unit was filled with sand and gravel as the porosity medium with a hydraulic retention time of 5 days. To analyze the efficiency of the wetlands, physical and chemical parameters were analyzed in the laboratory. The results obtained in the laboratory showed that the two species of macrophyte showed good efficiency in the removal of organic matter (100% COD-100% BOD5). On the other hand, Equisetum spp showed better efficiency in the removal of NO3− (80.28%) and PO43− (98.57%) meanwhile, Zantedeschia aethiopica showed better efficiency in the removal of TSS (85.71%). Constructed wetlands are an effective and sustainable option for wastewater treatment.

Decentralized Constructed Wetlands for Wastewater Treatment in Rural and Remote Areas of Semi-arid Regions

Vertical-flow constructed wetlands (VFCWs) are an innovative and sustainable nature-based technology for wastewater treatment in rural areas. This work aimed to evaluate the treatment performance of VFCWs using real wastewater, which can provide more accurate and reliable results compared with field-based experiments, and to investigate the use of Paulownia trees in VFCWs for wastewater treatment. To compare the efficiency of the plants based on the treatment performance of the VFCWs, three units were prepared and composed of Paulownia, the commonly used Phragmites Australis, and an unplanted unit used as a control during the experimental program. The results show significant reductions in both the chemical oxygen demand (COD) and biochemical oxygen demand (BOD5) levels for both planted units, with removal ratios for COD and BOD5 of 60% to 98%, respectively. Both Paulownia and Phragmites Australis significantly reduced the levels of COD and BOD5 in the effluent, with removal percentages ranging from 57.1% to 98% for COD and 49.1% to 98% for BOD5. The control unit, without plantings, showed a lower but still significant removal percentage for both COD (from 55.1% to 96.1%) and BOD5 (from 48.3% to 97.8%). Thus, the results reveal that the efficiency of constructed wetlands can be significantly enhanced by the presence of suitable plant species, such as Paulownia and Phragmites Australis, and constructed wetlands can be a viable and cost-effective option for the treatment of wastewater in various settings, with the added benefit of using the relevant biodiversity.

Full-scale application and performance of a new multi-self-reflow decentralized Wastewater treatment device: Impact of hydraulic and pollutant loads

Decentralized treatment of wastewater in rural areas usually has several challenges, which include large fluctuations in pollutant concentration and water quantity, complicated operation and maintenance of conventional biochemical treatment equipment, resulting in poor stability and a low compliance rate of the wastewater treatment process. In order to solve the above problems, a new integration reactor is designed, which uses gravity and aeration tail gas self-reflux technology to realize the reflux of sludge and the nitrification liquid, respectively. The feasibility and operation characteristics of its application for decentralized wastewater treatment in rural areas are explored. The results demonstrated that, under constant influent, the device showed strong tolerance to the shock of pollutant load. The chemical oxygen demand, NH4+-N, total nitrogen and total phosphorus fluctuated in the ranges of 95–715 mg/L, 7.6–38.5 mg/L, 9.32–40.3 mg/L and 0.84–4.9 mg/L, respectively. The corresponding effluent compliance rates were 82.1%, 92.8%, 96.4% and 96.3%, respectively. When the wastewater discharge was non-constant and the maximum single-day Qmax/Qmin reached 5, all indicators of the effluent met the relevant discharge standard. The integrated device also demonstrated high phosphorus enrichment levels in its anaerobic zone; the concentration of phosphorus reached a maximum of 26.9 mg/L, which created a good environment for phosphorus removal. The microbial community analysis showed that sludge digestion, denitrification, and phosphorus-accumulating bacteria all played an important role in pollutant treatment.

Treatment and technology of domestic sewage for improvement of rural environment in China

It has been recorded that China’s rural environment threatened the lives of people due to the large amounts of wastewater treatment. The domestic sewage treatment plants were implemented in many parts of China to improve the environment of the country, and it has been noted that this sewage had a positive effect on the Chinese Rural Environment. Past studies recorded that China reached building sewage treatment plants with the capacity of 125 million m3. Moreover, most of these treatment plants employed Activated Sludge Process (ASP) along with the package treatments such as Anoxix-Oxic processes, Anaerobic processes, Oxidatin Ditch, and Sequencing Batch Reactors. Still there seems to be a gap in the effectiveness of wastewater treatment plants constructed with wastewater rising day-to-day. The main purpose of the current study is to review the rural wastewater treatments such as sewage systems and other treatment plants, which will improve the rural environment in China. This paper also highlights the characteristics of rural domestic sewage treatment. Furthermore, this paper also explores the applicability of rural sewage treatment technology in rural places of China. The challenges of the wastewater treatment in rural areas of China will also be closely monitored by the researcher.

Quantifying Total Phosphorus and Heavy Metals in Residential Septage

Septic systems are used for wastewater treatment in rural areas. Septic tanks promote stratification of wastewater into solid (sludge and scum) and liquid layers. Pollutant concentrations in the layers of residential septic tanks may be highly variable, and thus septage pumped from tanks with different layer thicknesses may also be variable. The goal of this study was to quantify the total phosphorus (TP) and heavy metal concentrations and masses of residential septage. The solid and liquid layer thicknesses were measured in 37 septic tanks. Samples were collected from each layer for pollutant concentration analysis. The median TP concentration (10.6 mg L−1) was greatest in the sludge layer, followed by the scum (5.3 mg L−1) and liquid (1.8 mg L−1) layers. Concentrations of heavy metals were highly variable for each layer type. The masses of the TP, cadmium, copper, lead, nickel, and zinc contained median (range) values of 19.4 g (0.9–1041 g), <0.01 g (<0.01–1.99 g), 1.3 g (0.1–520 g), 1.8 g (<0.01–44.2 g), 1.3 g (<0.01–4.3 g), and 13.8 g (0.3–788 g), respectively. Since septage is typically applied on land as a soil amendment for crop growth, it is important that representative composite samples are collected to prevent excess buildup of TP and metals, which may harm yields or environmental health.

The efficiency of the economic septic tank in the treatment of domestic wastewater and black water in rural areas

Wastewater treatment in rural areas is important to prevent the pollution of aquatic environments and to protect the health of the population. Centralized treatment systems present a high cost, making the use of decentralized systems attractive. The use of septic tanks for on-site treatment of residential (single-family) is an attractive alternative within the context of Brazilian sanitation. Thus, the main objective of this study was to analyze the efficiency of the Economic Septic Tank in the treatment of wastewater of two residences located in a rural area. Two systems were installed: the first treat sanitary wastewater of a residence with three residents (A) and the second treat only the water from the toilet of a residence with five residents (B) (Black Water). For both systems, A and B, removal efficiencies were obtained in relation to total suspended solid (75%), biochemical oxygen demand (58 and 55%), and chemical oxygen demand (61 and 60%), respectively. Removal efficiencies were close, indicating that the system works satisfactorily in both systems, considering values indicated in the literature.

Integrating sulfur, iron(II), and fixed organic carbon for mixotrophic denitrification in a composite filter bed reactor for decentralized wastewater treatment: Performance and microbial community

Decentralized wastewater treatment in rural areas is an imperative challenge around the world, particularly in developing countries. The composite filter bed reactor is viable for decentralized wastewater treatment, but its performance on nitrogen removal often fluctuates with the unstable influent characteristics and loadings. Here, a composite filter bed reactor integrating sulfur, iron(II), and fixed organic carbon (shaddock peel) was developed and continuously operated under different conditions. The fixed organic carbon source promoted nitrogen removal with an efficiency higher than 90% and reduced effluent sulfate level by 40%, indicating that the integrated electron donors could improve the resistance and stability of the reactor. Moreover, sulfur-oxidizing bacteria (Thiomonas, Sulfuriferula, and Acidithiobacillus), iron-oxidizing bacteria (Ferritrophicum), and denitrifiers (Simplicispira and Hydrogenophaga) were identified in the anoxic/anaerobic layer of the reactor, suggesting that mixotrophic denitrification was stimulated by sulfur, iron(II), and fixed organic carbon. The findings of this study indicate that the developed reactor with the integrated electron donors could be reliable for carbon, nitrogen, and phosphorus removal and promising for the application of decentralized wastewater treatment.

Exploring the decentralized treatment of sulfamethoxazole-contained poultry wastewater through vertical-flow multi-soil-layering systems in rural communities

Sulfamethoxazole (SMX) is the most widely distributed sulfonamide antibiotics detected in decentralized poultry wastewater in rural communities. As an economically-feasible and eco-friendly technology for decentralized wastewater treatment in rural areas, vertical-flow multi-soil-layering (MSL) system was promising to mitigate the ecological and human health risks from SMX in such areas. The treatment of SMX-contained poultry wastewater by using MSL systems was investigated for the first time, and the main and interactive effects of related multiple variables on system performance were explored through factorial analysis, including material of permeable layer, concentration of SMX, and pH of influent. Results indicated that SMX concentration and pH of influent showed significantly negative effects on SMX removal. Medical stone used in MSL systems with larger surface area could intensify the SMX removal compared to anthracite. MSL systems showed stable performances on SMX removal with the best SMX removal efficiency more than 91%. A novel stepwise-cluster inference (SCI) model was developed for the first time to map the multivariate numeric relationships between state variables and SMX removal under discrete and nonlinear complexities. It was demonstrated that the effect of SMX in wastewater with high concentration was significant on the differentiation of soil bacteria composition in MSL systems based on microbial diversity analysis. These results can help better understand the mechanism of SMX removal in MSL systems from perspectives of factorial analysis, numeric modeling, and microbiological change.

Potential Application of Chilean Natural Zeolite as a Support Medium in Treatment Wetlands for Removing Ammonium and Phosphate from Wastewater

This study aims to evaluate the sorption characteristics of NH 4 + -N and PO 4 3 − -P onto the surface of natural zeolites coming from Chile and their potential application in the subsurface-flow treatment wetlands for wastewater treatment in rural areas. For this purpose, adsorption experiments onto the zeolite were developed in batch assays. The effects of the adsorbent quantity (20 g and 50 g) and particle size (0.2–1.0 mm; 1.5–3.0 mm, and 5.0–8.0 mm) were evaluated in terms of adsorption capacity at different NH4+-N and PO4−3-P concentrations. Then, the obtained laboratory results were adjusted to theoretical models: Saturation-growth-rate and Langmuir. The saturation adsorption of NH4+-N on the zeolite increases at the same time that the initial concentration increases for the same zeolite quantity; however, the saturation values were similar between the different zeolite sizes tested. For PO4−3-P, the adsorption did not have a direct relationship with the initial concentration nor zeolite quantity and better results were only achieved for zeolite sizes of 1.5–3.0 mm. Regarding the Langmuir model, sizes of 1.5–3.0 mm had the best adsorption characteristics, with the maximum adsorption capacity of up to 1.58 mg/g for NH4+-N and up to 0.08 mg/g for PO4−3-P. Therefore, a new material—a natural zeolite from the Maule Region of Chile—is described as a potential support medium for treatment wetlands.

Surface Water and Groundwater Quality in South Africa and Mozambique—Analysis of the Most Critical Pollutants for Drinking Purposes and Challenges in Water Treatment Selection

According to a recent report by the World Health Organization (WHO), the countries which still have limited access to water for drinking purposes are mainly those in the Sub-Saharan region. In this context, the current study provides an overview of the quality of surface water and groundwater in rural and peri-urban areas of the Republic of South Africa (RSA) and Mozambique (MZ) in terms of concentrations of conventional pollutants, inorganic chemicals, microorganisms, and micropollutants. Their values were compared with the drinking water standards available for the two countries. Regarding surface water, it was found that microorganisms occur at high concentrations; nickel (RSA) and boron (MZ) are other critical parameters. Regarding groundwater, arsenic and lead (RSA) and boron, sodium, and chloride (MZ) are the main critical substances. With regard to micropollutants, their surface water concentrations are much higher than those in European rivers. The highest values were for ibuprofen, acetylsalicylic acid, clozapine, and estriol. Suitable treatment is necessary to produce safe water depending on the main critical pollutants but, at the same time, action should be taken to improve wastewater treatment in rural areas to improve and safeguard surface water bodies and groundwater which are sources for drinking needs.

Towards the new era of wastewater treatment of China: Development history, current status, and future directions

Water is essential for the sustainable development of human society. With the largest population and rapid economic development, water usage and treatment in China have grown tremendously in the past decades. In order to prevent water pollution, the standards for wastewater effluent discharge in China have been gradually developed and implemented since 1973. After the rapid development during over 40 years, numerous milestones have been achieved in terms of infrastructure coverage, standard and policy system establishment, and technological innovations. In this article, we reviewed the development history and the current status of the wastewater treatment in China, including the generation of wastewater, the construction of wastewater treatment plants (WWTPs), the overall treatment performance of WWTPs, as well as the developments in effluent discharge standards. In addition, we highlighted the challenges lying ahead in the aspects of influent concentration, sludge disposal and water reclamation. Based on the achievement and foundation built in the past, the new era of wastewater treatment of China is on the way, in which water reclamation, wastewater treatment in rural areas and resource/energy recovery from sludge are becoming the main tasks.

The present situation and trends of wastewater treatment in small settlements and rural areas of Lithuania

This article presents the wastewater treatment in small settlements and rural areas ofLithuania, including descriptions of capacity and loading of wastewater treatment plants(WWTPs), types of treatment facilities, and development trends of biological treatmentfacilities. In 2000 Lithuania had 597 WWTPs with capacity up to 1000 m3/d, 95% of them arethe biological treatment plants. Today the most of these WWTPs are unloaded due to thetendency to centralise wastewater treatment in rural areas of Lithuania that were in the eightand ninth decades.In small settlements and rural areas of Lithuania the aeration facilities are predominant. In theeight and ninth decades practically only the activated sludge systems were built. The situationbegan to change in the last decade of the last century: the biological filters and soil filtrationfacilities with discharge into surface waters were applied more frequently, so the building ofaeration facilities started to decrease.

Management of wastewater in rural districts of Istanbul metropolitan municipality.

Decentralized systems play a big role in wastewater treatment in rural areas. The aims of this study are to address the wastewater treatment and disposal problems for rural districts of Istanbul, to discuss the efficiencies of currently operated systems and to offer new appropriate wastewater treatment systems for small communities having a population up to 5,000. The management and final disposal alternatives for sludge generated in septic tanks are also discussed within the scope of this study. A sequencing batch reactor (SBR) system serving 2,500 people and a hybrid constructed wetland system serving 500 people are presented as case studies. A thorough evaluation based on the capacity and performance of the existing wastewater treatment systems in rural districts revealed that a number of these systems are not operating at their optimum. Improperly constructed sewer lines receive a lot of infiltration and inflow (I & I) after rainfall events, decreasing treatment performance and causing operational difficulties. Natural treatment systems such as constructed wetlands prove a viable alternative in these communities, especially for villages with populations less than 500 people.

Feasibility of sand filters to wastewater treatment in rural areas in Algeria: experimental study

Feasibility of sand filters to wastewater treatment in rural areas in Algeria: experimental study

Feasibility of sand filters to wastewater treatment in rural areas in Algeria: experimental study

The treatment of domestic wastewater by sand filters is a very interesting alternative technique to collective sewerage in rural areas. In order to assess the accuracy of this technique in Algeria, a feasibility study based on a statistical survey and an experimental study is carried out. The aim of the statistical survey is to determine the potential for the application of this technique by evaluating the rate of connection to collective sewerage networks and the existence of a sewage treatment system in rural areas. The purpose of the experimental study is to assess the suitability of the local sands for this type of process. In this paper the treatment performance over time of two different sands (medium and coarse) are evaluated. The chemical analyses of wastewater and filtered water showed a removal ranges between 57% and 74% for medium sand and between 7% and 49% for coarse sand.

Imbalanced Development and Economic Burden for Urban and Rural Wastewater Treatment in China—Discharge Limit Legislation

Water pollution control is a great challenge for China. Compared with urban regions, the wastewater treatment in rural areas is much undeveloped, which is highly related with the much delayed legislation for rural wastewater. Imbalanced urban-rural development and the economic burden of urban and rural wastewater treatment in China was investigated from the perspective of discharge limit legislation. For now, the national discharge limit for rural wastewater is still vacant, although the national discharge limit for urban wastewater had been released for more than ten years. Recently, local rural wastewater discharge limits from several provinces were released, however, based on quite different principles. Some categories emphasized environmental sensitivity with the discharge limit equal and were more strict than urban standards, while some focused on resource recovery for rural regions with loose discharge limits. This study compared the financial burden between rural and urban regions in 31 provinces under different discharge limit legislation conditions. It was revealed that the resources recovery category discharge principle helped to decrease the financial burden imbalance with a reduced Gini coefficient from 0.37 to 0.17. The reduced economic burden from the implementation of a suitably designed rural discharge limit promoted balancing the rural-urban gap and lowering uncertainties and risk of sustainable rural wastewater treatment. This study also revealed the urgency of rural water legislation and proposed development with a balanced financial burden for urban and rural residents under suitable discharge limits, providing a profound insight for environmental management with a focus on balanced urban-rural development for the policy-makers in developing countries.

Wastewater Treatment in Chinese Rural Areas

In the last 10 years, the extent of wastewater treated in China has increased by 57%, the great amounts of sewage have threatened people's health as well the natural environment. In the last 10 years, the sewage treatment rate has improved, in December 2013, 99.1% of Chinese cities and 82.6% counties have sewage treatment plants. This review paper describes the current situation and has suggestion of how to overcome future sewage problems especially water pollution in China from domestic, agriculture and industrial sectors. It also discusses the urban/ rural wastewater for treatment including sewerage systems, treatment plants and water quality standards in China. The paper highlights the challenges of effective wastewater treatment in rural areas as a particular issue due to lack of monitoring and law support. This has led to ineffective management of treatment plants, financial difficulties; inappropriate sewerage, treatment facilities and standards; as well as poor awareness.

Enhanced long-term organics and nitrogen removal and associated microbial community in intermittently aerated subsurface flow constructed wetlands

The long-term enhanced removal efficiency of organics and nitrogen in subsurface flow constructed wetlands (SSF CWs) with and without intermittent aeration for decentralized domestic wastewater was evaluated, and the function of intermittent aeration on microbial community was also investigated in this study. The high and long-term 95.6% COD, 96.1% NH4+-N and 85.8% TN removal efficiencies were achieved in experimental intermittently aerated SSF CW compared with non-aerated SSF CW. Aerated SSF CWs also exhibited the excellent removal performance when comparatively comparing with other strategies and techniques applied in CWs. In addition, fluorescence in situ hybridization (FISH) analysis revealed that associated microbial abundance significantly increased owing to intermittent aeration. These results indicated intermittent aeration CWs might be an effective and sustainable strategy for wastewater treatment in rural areas, but require further full-scale investigation in future.

Potential of Constructed Wetland for Wastewater Treatment in Rural Areas in Kosovo

Potential of Constructed Wetland for Wastewater Treatment in Rural Areas in Kosovo

The treatment performance and nutrient removal of a garden land infiltration system receiving dairy farm wastewater

Livestock wastewater is a major source of agricultural non-point pollution. Land treatment system is appropriate for livestock sewage treatment due to its low construction cost and high treatment performance. In this study, a garden land infiltration system (GLIS) was established to treat dairy farm wastewater. Our main concern was nutrient removal and plant uptake when the system is in operation. The removal rates in the outflow water of suspended solids (SS), NH4+N, total N (TN), total P (TP), chemical oxygen demand (COD), and total organic carbon (TOC) were 86.1%, 78.0%, 78.2%, 94.6%, 76.8%, and 74.6%, respectively. Approximately 79.4–81.6kg/ha of nitrogen and 9.1–13.1kg/ha of phosphorus were removed from the system by ryegrass harvesting, which accounted for 14.5–14.9% and 17.0–24.6% of the TN and TP in the effluent, respectively. These results demonstrate that the system has the advantage of high performance efficiency and has the potential for greater nutrient removal by plant uptake. Therefore, a GLIS can be considered as a viable alternative for dairy farm wastewater treatment in rural areas.