scholarly journals Evaluation of fouling and RO performance for MBR treated fruit wastewater

2020 ◽  
Vol 82 (11) ◽  
pp. 2282-2295
Author(s):  
A. T. Jamal-Uddin ◽  
R. G. Zytner
Keyword(s):  
Best Management Practices ◽  
Membrane Fouling ◽  
Water Reuse ◽  
Management Practices ◽  
Membrane Surface ◽  
Good Alternative ◽  
Sorption Process ◽  
Fruit Processing ◽  
Ro Membrane ◽  
The Impact

Abstract Fruit processing facilities are looking for ways to reduce water consumption to counter the impact of climate change. A good alternative is an MBR system to treat the processing wastewater, followed by tertiary treatment using a reverse osmosis (RO) unit to enable water reuse. However, fouling of the RO membrane causes operational challenges. As a result, experiments were completed on treated fruit processing wastewater to identify the causes of fouling that originated from the MBR effluent and develop best management practices (BMPs) to minimize fouling of the RO membrane. Physical and chemical analyses along with visual inspection of the membrane surface using scanning electron microscopy (SEM), energy diffusive X-ray (EDX) and Fourier transform infrared (FTIR) spectroscopy were completed. The issue of RO membrane fouling and subsequent flux decline was directly related to the presence of soluble microbial products, specifically dissolved organic matter (DOM) in the MBR effluent. The developed BMPs show that the previously completed enhanced coagulation-GAC sorption process, when combined with an online non-chemical flushing regimen and proper membrane preservation, keeps the flux readings high, resolving frequent fouling and cleaning problems of the RO membrane.

scholarly journals Assessing the Potential of Nontraditional Water Sources for Landscape Irrigation

2018 ◽  
Vol 28 (4) ◽  
pp. 436-444 ◽  
Author(s):  
Raul I. Cabrera ◽  
James E. Altland ◽  
Genhua Niu
Keyword(s):  
Best Management Practices ◽  
Urban Areas ◽  
Management Practices ◽  
Urban Landscape ◽  
Biological Properties ◽  
Water Sources ◽  
Long Term Effects ◽  
Natural Ecosystems ◽  
Aesthetic Quality ◽  
The Impact

Scarcity and competition for good quality and potable water resources are limiting their use for urban landscape irrigation, with several nontraditional sources being potentially available for these activities. Some of these alternative sources include rainwater, stormwater, brackish aquifer water, municipal reclaimed water (MRW), air-conditioning (A/C) condensates, and residential graywater. Knowledge on their inherent chemical profile and properties, and associated regional and temporal variability, is needed to assess their irrigation quality and potential short- and long-term effects on landscape plants and soils and to implement best management practices that successfully deal with their quality issues. The primary challenges with the use of these sources are largely associated with high concentrations of total salts and undesirable specific ions [sodium (Na), chloride (Cl), boron (B), and bicarbonate (HCO3−) alkalinity]. Although the impact of these alternative water sources has been largely devoted to human health, plant growth and aesthetic quality, and soil physicochemical properties, there is emergent interest in evaluating their effects on soil biological properties and in natural ecosystems neighboring the urban areas where they are applied.

scholarly journals Perceived vulnerability and propensity to adopt best management practices for huanglongbing disease of citrus in California

2021 ◽  
Author(s):  
Sara Garcia Figuera ◽  
Holly Deniston-Sheets ◽  
Elizabeth E Grafton-Cardwell ◽  
Bruce Babcock ◽  
Mark Lubell ◽  
...  
Keyword(s):  
Best Management Practices ◽  
Management Practices ◽  
Control Program ◽  
Integrated Approach ◽  
Perceived Vulnerability ◽  
Best Management ◽  
Preventive Practices ◽  
Citrus Groves ◽  
Plant Disease Management ◽  
The Impact

Huanglongbing (HLB) disease of citrus, associated with the bacterium “Candidatus Liberibacter asiaticus”, is confined to residential properties in Southern California eight years after it was first detected in the state. To prevent the spread of HLB to commercial citrus groves, growers have been asked to adopt a portfolio of voluntary best management practices. This study evaluates the citrus industry’s propensity to adopt these practices using surveys and a novel multivariate ordinal regression model. We estimate the impact on adoption of perceived vulnerability to HLB, intentions to stay informed and communicate about the disease and various socio-economic factors, and reveal what practices are most likely to be jointly adopted as an integrated approach to HLB. Survey participants were in favor of scouting and surveying for HLB symptoms, but they were reluctant to test trees, use early detection technologies (EDTs) or install barriers around citrus groves. Most practices were perceived as complementary, particularly visual inspections and some combinations of preventive practices with tests and EDTs. Participants who felt more vulnerable to HLB had a higher propensity to adopt several practices, as well as those who intended to stay informed and communicate with the coordinators of the HLB control program, although this effect was modulated by the perceived vulnerability to HLB. Communication with neighbors and the size of citrus operations also influenced practice adoption. Based on these results, we provide recommendations for outreach about HLB management in California and suggest future directions for research about the adoption of plant disease management practices.

scholarly journals The Role of Electric Power Sector in China’s Global Economic Expansion

2019 ◽  
Vol 12 (6) ◽  
pp. 188-202
Author(s):  
R. A. Epikhina
Keyword(s):  
Developing Countries ◽  
Best Management Practices ◽  
Nuclear Power ◽  
Management Practices ◽  
Power Transmission ◽  
Developed Countries ◽  
Electricity Sector ◽  
Power Sector ◽  
Economic Expansion ◽  
The Impact

The article discusses some of the major characteristics and trends of China’s economic expansion in the global power industry. It argues that by investing in electricity infrastructure China creates prerequisites for long-term dominance in one of the key sectors in a number of countries and regions. Deals in the power sector are mainly implemented by state-owned companies and facilitated by state-owned financial institutions. In terms of structure and geography, foreign investment in the electricity sector is dominated by traditional types of generation in developing countries. However, China has been diversifying into renewables, nuclear power and grids and entering markets of the developed countries. The creation of a special international organization (GEIDCO) should facilitate its expansion in the electricity sector abroad. It is worth noting that foreign economic expansion plays an important role in supporting China’s slowing economy amid the transformation of its growth model. It allows China to adopt advanced technologies and best management practices in developed countries while forming alternative value chains, as well as promoting its own equipment and standards (especially in ultra-high voltage power transmission) in the developing countries. However, given the impact of the trade war, increasing securitization of the Chinese foreign investments, Chinese authorities’ control over capital outflows and the rising environmental concerns in developing countries, further expansion of the Chinese capital in the global electricity industry is likely to be held back, while competition from non-Chinese electricity companies is likely to grow.

scholarly journals Removal Characteristics of N-Nitrosamines and Their Precursors by Pilot-Scale Integrated Membrane Systems for Water Reuse

2018 ◽  
Vol 15 (9) ◽  
pp. 1960 ◽  
Author(s):  
Haruka Takeuchi ◽  
Naoyuki Yamashita ◽  
Norihide Nakada ◽  
Hiroaki Tanaka
Keyword(s):  
Membrane Fouling ◽  
Water Reuse ◽  
Pilot Scale ◽  
Feed Water ◽  
Water Reclamation ◽  
Size Distributions ◽  
Membrane Systems ◽  
Chemical Cleaning ◽  
Ro Membrane ◽  
Feed Water Temperature

This study investigated the removal characteristics of N-Nitrosamines and their precursors at three pilot-scale water reclamation plants. These plants applies different integrated membrane systems: (1) microfiltration (MF)/nanofiltration (NF)/reverse osmosis (RO) membrane; (2) sand filtration/three-stage RO; and (3) ultrafiltration (UF)/NF and UF/RO. Variable removal of N-Nitrosodimethylamine (NDMA) by the RO processes could be attributed to membrane fouling and the feed water temperature. The effect of membrane fouling on N-Nitrosamine removal was extensively evaluated at one of the plants by conducting one month of operation and chemical cleaning of the RO element. Membrane fouling enhanced N-Nitrosamine removal by the pilot-scale RO process. This finding contributes to better understanding of the variable removal of NDMA by RO processes. This study also investigated the removal characteristics of N-Nitrosamine precursors. The NF and RO processes greatly reduced NDMA formation potential (FP), but the UF process had little effect. The contributions of MF, NF, and RO processes for reducing FPs of NDMA, N-Nitrosopyrrolidine and N-Nitrosodiethylamine were different, suggesting different size distributions of their precursors.

scholarly journals Soil Temperatures of the Transylvanian Plain, Romania

1970 ◽  
Vol 66 (1) ◽  
Author(s):  
David WEINDORF ◽  
Beatrix HAGGARD ◽  
Teodor RUSU ◽  
Horea CACOVEAN ◽  
Stephanie JOHNSON
Keyword(s):  
Soil Moisture ◽  
Best Management Practices ◽  
Annual Variation ◽  
Management Practices ◽  
Physicochemical Analysis ◽  
Slope Aspect ◽  
Best Management ◽  
Important Region ◽  
Soil Temperatures ◽  
The Impact

The Transylvanian Plain, Romania is an important region for agronomic productivity. However, limited soils data and adoption of best management practices can hinder land productivity. Soil temperatures of the Transylvanian Plain were evaluated using a set of twenty datalogging stations positioned throughout the plain. Soil temperatures were monitored at the surface, 10 cm, 30 cm, and 50 cm, and soil moisture was monitored at 10 cm. Pedons were excavated, described, and sampled for physicochemical analysis. Preliminary results indicate that most soils of the Transylvanian Plain will have a mesic temperature regime. However, differences in seasonal warming and cooling trends across the plain were noted. These have important implications for planting recommendations. Some soils of the plain were noted to freeze at 50 cm, while others did not. Longer term study of temperatures of the Transylvanian Plain will average out annual variation in soil temperature and evaluate the impact of slope aspect, slope inclination, soil moisture, and physicochemical properties on soil temperatures.

scholarly journals Recycling of Reverse Osmosis Concentrates to the Membrane Bioreactor in the MBR-RO Process for Water Reuse: effect on mbr performances

2017 ◽  
Vol 30 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Thi Thu Nga Vu ◽  
Manon Montaner ◽  
Christelle Guigui
Keyword(s):  
Organic Matter ◽  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Water Reuse ◽  
High Performance ◽  
Membrane Bioreactor ◽  
Membrane System ◽  
Size Exclusion ◽  
Ro Concentrate ◽  
The Impact

Wastewater effluents can be treated by an integrated membrane system combining membrane bioreactor (MBR) and reverse osmosis (RO) for effective removal of micropollutants in the field of high-quality water reuse. However, discharging the RO concentrate waste stream directly into the natural environment could lead to serious problems due to the toxic components contained in the concentrates (micropollutants, salts, organic matter). A possible solution could be the recirculation of RO concentrate waste to the MBR. However, such an operation should be studied in detail since the recirculation of non-biodegradable organic matter or high concentrations of salts and micropollutants could directly or indirectly contribute to MBR membrane fouling and modification of the biodegradation activity. In this context, the work reported here focused on the recirculation of such concentrates in an MBR, paying specific attention to MBR membrane fouling. Lab-scale experiments were performed on a continuous MBR-RO treatment line with RO concentrate recirculation. The main goal was to determine the recovery of the RO unit and of the global process that maintained good process performance in terms of biodegradation and MBR fouling. The results demonstrate that the impact of the toxic flow on activated sludge depends on the recovery of the RO step but the same trends were observed regardless of the organic matter and salt contents of the concentrates: the concentration of proteins increased slightly. Size-exclusion high performance liquid chromatography (HPLC-SEC) was employed to study the effects of RO concentrate on the production of protein-like soluble microbial products (SMPs) and demonstrated a significant peak of protein-like substances corresponding to 10-100 kDa and 100-1 000 kDa molecules in the supernatant. Thus a significant increase in the propensity for sludge fouling was observed, which could be attributed to the increased quantity of protein-like substances. Finally, the effect of the concentrate on sludge activity was studied and no significant effect was observed on biodegradation, indicating that the return of the concentrate to the MBR could be a good alternative.

scholarly journals Assessing the Impact of Best Management Practices in a Highly Anthropogenic and Ungauged Watershed Using the SWAT Model: A Case Study in the El Beal Watershed (Southeast Spain)

Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 576 ◽  
Author(s):  
Adrián López-Ballesteros ◽  
Javier Senent-Aparicio ◽  
Raghavan Srinivasan ◽  
Julio Pérez-Sánchez
Keyword(s):  
Coastal Lagoon ◽  
Best Management Practices ◽  
Management Practices ◽  
Assessment Tool ◽  
Swat Model ◽  
Fertilizer Application ◽  
Coefficient Of Determination ◽  
Check Dam ◽  
Best Management ◽  
The Impact

Best management practices (BMPs) provide a feasible solution for non-point source pollution problems. High sediment and nutrient yields without retention control result in environmental deterioration of surrounding areas. In the present study, the soil and water assessment tool (SWAT) model was developed for El Beal watershed, an anthropogenic and ungauged basin located in the southeast of Spain that drains into a coastal lagoon of high environmental value. The effectiveness of five BMPs (contour planting, filter strips, reforestation, fertilizer application and check dam restoration) was quantified, both individually and in combination, to test their impact on sediment and nutrient reduction. For calibration and validation processes, actual evapotranspiration (AET) data obtained from a remote sensing dataset called Global Land Evaporation Amsterdam Model (GLEAM) were used. The SWAT model achieved good performance in the calibration period, with statistical values of 0.78 for Kling–Gupta efficiency (KGE), 0.81 for coefficient of determination (R2), 0.58 for Nash–Sutcliffe efficiency (NSE) and 3.9% for percent bias (PBIAS), as well as in the validation period (KGE = 0.67, R2 = 0.83, NS = 0.53 and PBIAS = −25.3%). The results show that check dam restoration is the most effective BMP with a reduction of 90% in sediment yield (S), 15% in total nitrogen (TN) and 22% in total phosphorus (TP) at the watershed scale, followed by reforestation (S = 27%, TN = 16% and TP = 20%). All effectiveness values improved when BMPs were assessed in combination. The outcome of this study could provide guidance for decision makers in developing possible solutions for environmental problems in a coastal lagoon.

scholarly journals Review of attitudes and awareness in the agricultural industry to diffuse pollution issues

2005 ◽  
Vol 51 (3-4) ◽  
pp. 373-381 ◽  
Author(s):  
D. Merrilees ◽  
A. Duncan
Keyword(s):  
Best Management Practices ◽  
Management Practices ◽  
Technical Information ◽  
Diffuse Pollution ◽  
Mitigation Measures ◽  
Agricultural Industry ◽  
Agricultural Enterprises ◽  
Farming Industry ◽  
Farm Business ◽  
The Impact

The Scottish Executive considers ‘Diffuse Pollution from Agricultural Enterprises’ as a priority issue over the next 5-10 years and recognises the need to improve knowledge transfer, advice and training amongst farmers, crofters, contractors and advisers. The Scottish Environment Protection Agency commissioned SAC to survey advisory staff on diffuse pollution issues, mitigation measures and delivery of environmental advice to the farming industry. This showed that the impact of agricultural diffuse pollution on the environment is considered a serious problem as is the future impact of legislation on farm business. There is an urgent requirement to raise advisers' awareness of environmental legislation and of mitigation measures. Advisers consider that farmers have limited awareness of diffuse pollution problems but those that do would consider the impact on the environment to be serious. There is a lack of knowledge on the effectiveness of pollution mitigation measures. Better technical information, supported by research, is required. This information is best conveyed to advisers via the internet, technical notes and directly by environmental specialists and delivered on to farmers by farm visits. Lack of funds prevents most farmers adopting best management practices and more than 80% of advisers consider that environmental advice should be free.

scholarly journals In-line coagulation assessment for ultrafiltration fouling reduction to treat secondary effluent for water reuse

2020 ◽  
Author(s):  
Samia A. Aly ◽  
William B. Anderson ◽  
Peter M. Huck
Keyword(s):  
Membrane Fouling ◽  
Water Reuse ◽  
Hollow Fiber Membrane ◽  
Secondary Effluent ◽  
Membrane Performance ◽  
Coagulant Dosage ◽  
Pre Treatment ◽  
Uf Membranes ◽  
Fouling Reduction ◽  
The Impact

Abstract Low pressure membranes are attracting attention for their potential to improve secondary effluent quality, but membrane fouling can limit their widespread applicability. In this study, in-line coagulation as pre-treatment to ultrafiltration (UF) was investigated using a bench-scale hollow fiber membrane at a constant flux of 33 L/m2 h. Membrane fouling was monitored by observing change in trans-membrane pressure when the membrane was fed with secondary effluent and in-line coagulated secondary effluent over a 24-h period. The impact of four coagulants at different dosages on reversible and irreversible membrane fouling and permeate quality was studied. It was found that in-line coagulation improved UF performance to varying degrees depending on coagulant type and dosage. Generally, higher reduction of fouling was achieved by increasing coagulant dosage within the 0.5–5.0 mg/L range investigated. Ferric-based coagulants were better than aluminum-based coagulants with respect to improving membrane performance for the secondary effluent investigated, even at low dosages (0.5 mg/L). Further investigations are required to determine how in-line coagulation affects removal of organic compounds through UF membranes.

scholarly journals The Impact of the Louisiana Master Gardener Program on the Perceived and Actual Horticultural Knowledge of Program Participants

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 968E-969
Author(s):  
Bobby H. Fletcher ◽  
Michael F. Burnett ◽  
Krisanna L. Machtmes ◽  
Jeff S. Kuehny
Keyword(s):  
Best Management Practices ◽  
Management Practices ◽  
The United States ◽  
Master Gardener ◽  
Perceived Knowledge ◽  
Highly Educated ◽  
Best Management ◽  
Before And After ◽  
Knowledge And Practice ◽  
The Impact

The primary purpose of this study was to determine the impact of participation in the Master Gardener program on horticultural knowledge and practice. In 1972, the “Master Gardener” concept was initiated in Washington State due to the high demand to answer consumer horticultural questions. The main objective of this program is to increase horticultural knowledge of program participants so they can transfer this information to consumer horticultural clientele. The program quickly spread throughout the United States. It reached Louisiana in 1994 and was expanded throughout most metropolitan areas by 1997. No formal evaluation has been conducted to determine the horticultural knowledge impacts of this program. All 257 participants in the 2004 Louisiana Master Gardener (LMG) program were surveyed before and after participation in this program. The survey used was a researcher-developed instrument designed to measure self-perceived knowledge, tested knowledge, and Best Management Practices (BMPs) used. Data were collected by master gardener coordinators and submitted to the researcher after each phase of data collection (pre and post). Results of the study revealed that the LMG participants were highly educated, mostly Caucasian, and mostly female. Significant improvements were identified in all of the knowledge and practice measurements included in the study. These included self-perceived knowledge, tested knowledge, and use of BMPs. It was concluded that the 2004 Louisiana Master Gardener program was effective in increasing the self-perceived horticultural knowledge and tested horticultural knowledge of program participants. In addition, the study concluded that the 2004 Louisiana Master Gardener program improved the use of BMPs among the participants.

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