Maintenance Of Wastewater Treatment Plants Research Articles

The call for regional design code from the regional discrepancy of microbial communities in activated sludge.

Discerning the differences in activated sludge (AS) microbial community due to geographic location and environmental and operational factors is of great significance for precise design and maintenance of wastewater treatment plants (WWTPs). Hence, in this study, 150 AS samples collected from WWTPs in South China and North China were analyzed by 16S rRNA gene sequencing. In general, AS microbial community in North China had lower diversity, higher proportions of stochastic assembly (35.7% v.s. 15.8%) and more network keystone species (19 v.s. 5) compared with southern AS community. Conductivity and SRT had significant effects on AS community in both regions. Latitude, annual mean temperature, and influent BOD, COD, and ammonia influenced South China community significantly, while pH and influent total phosphorus affected North China community. To achieve stable performance, southern WWTPs should carefully monitor fluctuations in wastewater characteristics, while northern WWTPs should monitor AS communities for shifts in the dominant taxa from immigrant strains brought in through the influent. Additionally, WWTPs in North China should be aware of the need to proactively control sludge bulking because of the high abundance and occurrence of Haliscomenobacter in these AS communities. MAIN FINDING: The call for regional design based on the regional discrepancy of microbial communities in activated sludge is uncovered and according suggestions were given.

Urbanisation, climate change and its impact on water quality and economic risks in a water scarce and rapidly urbanising catchment: case study of the Berg River Catchment

Abstract By 2050 it is predicted that 67% of the world population is expected to be living in urban areas, with the most rapid levels of urbanisation taking place in developing countries. Urbanisation is often directly linked to the degradation of environmental quality, including quality of water, air and noise. Concurrently, the climate is changing. Together, the negative impacts of climate change and urbanisation pose significant challenges, especially in developing countries where resources to mitigate these impacts are limited. Focusing on the Berg River Catchment in South Africa, which is experiencing increasing levels of urbanisation, the impacts of climate change, the ‘wicked problem’ of service delivery to the historically disadvantaged within a developing country, persistent infrastructure backlogs, and where high unemployment is prevalent, this paper explores the increasing water quality risks due to climate change and rapid urban development and the likely direct and indirect economic impacts that this will have on the agriculture sector, which is a key contributor to the regional and national economy. The results give support to the need to invest in risk mitigation measures including the provision of basic services, the upgrading and maintenance of wastewater treatment plants and investing in ecological infrastructure.

Wastewater management training critical to future success of utilities in US‐Mexico border region

A new binational program to train wastewater treatment operators at facilities on the US‐Mexico border has been launched and will provide both classroom and hands‐on training in the operation and maintenance of wastewater treatment plants to facilitate compliance with current effluent quality standards.

Operation and Maintenance of Wastewater Treatment Plants: Case Studies in China

This paper considers on-going problems relevant to operation and maintenance in wastewater treatment plants in China. Positive and negative practices in developed countries such as the UK and U.S. have been indicated for the purposes of comparison. This research looks at the aspects of institutional structure, human resource management, public participation, financial resources, and technical management which have been regarded as the key points to analyse for effective wastewater management. Relevant information has been collected and analysed to develop appropriate solutions that would assist decision-makers and operators to solve some of the problems of wastewater management and to operate and maintain wastewater treatment plants in China properly.

The water situation in Harare, Zimbabwe: a policy and management problem

Harare, the capital city of Zimbabwe, is facing water quantity and quality problems, with serious pollution of the downstream Lake Chivero. Often, these problems are attributed to rapid population growth, inadequate maintenance of wastewater treatment plants, expensive technologies and a poor institutional framework. Rampant urban agriculture could also result in washing off and leaching of nutrients. This paper brings out a number of issues related to sustainable water management in Harare. The study was based on key informant interviews, focus group discussions and a literature review. The results show that monitoring and enforcement of regulations in Harare is poor because of economic hardships and lack of political will to deal with offenders. Also, there is irregular collection of garbage, low fines owing to hyper-inflation and a general failure by the city to collect water and other charges from residents. The city has also failed to raise tariffs to economic levels owing to heavy lobbying by residents and interference by government. It was concluded that Harare cannot overcome its water-related problems under the current set-up. It is recommended that a corporatised body, free from political influence and with a higher degree of autonomy, be established to run the water services for Harare and the neighbouring towns. Such a body would need a sound and flexible system for setting tariffs and enacting/enforcing reasonable regulations.

Physico-chemical Treatment of Wastewater From Clusters of Small Scale Cotton Textile Units

Small scale industries can not own individual wastewater treatment facility due to non-availability of land and skilled manpower for operation and maintenance of wastewater treatment plants. A centralized wastewater treatment facility for clusters of small scale industries is appropriate. This concept is gaining popularity in recent years. In India, various textile process operations are undertaken by individual small scale units. The wastewater generated at these units is conveyed to a common effluent treatment facility comprising of equalization, flocculation-clarification, activated sludge process, secondary clarification and finally discharge into inland surface water bodies. The wastewater from small scale cotton textile processing units was highly coloured and alkaline with average BOD and COD concentration of 205 and 790 mgl−1, respectively. Due to the presence of several dyes, particularly reactive dyes, the biological treatment is often found less effective. Therefore, applicability of various physico-chemical treatment methods needs to be investigated in pursuit of an alternative to biological treatment of textile wastewater. A physico-chemical treatment scheme, involving chemical coagulation-sedimentation, dual media filtration, activated carbon adsorption followed by chemical oxidation was investigated in this paper. The quality of final treated wastewater in terms of BOD and COD was 18-24 and 230-240 mgl−1, respectively through this scheme. A scheme of treatment comprising coagulation-sedimentation, dual media filtration, activated carbon, chemical oxidation may be considered as an alternative to biological treatment of textile wastewater.

Human excreta for plant production

Human excreta are a natural resource which is always available in all societies. Unfortunately, their value is highly underestimated in present agriculture and horticulture including in many tropical developing countries. Especially human urine is rich in nitrogen. This “free” fertiliser should be used as much as possible and needed. In many cases, human urine and composted human faeces could be fortified with wood ash and kitchen and garden waste to meet the potassium and phosphorus needs of plants and to improve soil structure. Avoiding health risks and dosage requirements are also discussed. The ideas presented here can be used even with the cheap pit latrines that are common in the rural and peri-urban areas of developing countries. They do not require electricity and/or tap water. They may also fit conditions in areas of Eastern Europe where piped water and sewerage are absent and/or people lack money for fertilisers and maintenance of wastewater treatment plants.

Assessment of the efficiency of sewage treatment plants: a comparative study between Nagasandra and Mailasandra sewage treatment plants

Bangalore city hosts two Urban Wastewater Treatment Plants (UWTPs) towards the periphery of Vrishabhavathi valley, located in Nellakedaranahalli village of Nagasandra and Mailasandra Village, Karnataka, India. These plants are designed and constructed with an aim to manage wastewater so as to minimize and/or remove organic matter, solids, nutrients, disease-causing organisms and other pollutants, before it reenters a water body. It was revealed from the performance study that efficiency of the two treatment plants was poor with respect to removal of total dissolved solids in contrast to the removal/reduction in other parameters like total suspended solids, BOD and COD. In Mailasandra STP, TDS, TSS, BOD, and COD removal efficiency was 20.01, 94.51, 94.98 and 76.26 % and respectively, while in Nagasandra STP, TDS, TSS, BOD, and COD removal efficiency was 28.45, 99.0, 97.6 and 91.60 % respectively. The order of reduction efficiency was TDS < COD < TSS < BOD and TDS < COD < BOD < TSS respectively in Mailasandra and Nagasandra STPs. Additionally, the problems associated with the operation and maintenance of wastewater treatment plants is discussed. Keywords: Total dissolved solids; Chemical oxygen demand; Biochemical oxygen demand; Aeration tank; Mixed liquor suspended solids; Sludge volume index DOI: 10.3126/kuset.v6i2.4020Kathmandu University Journal of Science, Engineering and Technology Vol.6. No II, November, 2010, pp.115-125