Water Discharge Regulations Research Articles

Ammonium Removal in Wastewater Treatments by Adsorbent Geopolymer Material with Granite Wastes: Full-Scale Validation

Elevated ammonium (NH4+) concentrations in untreated waterways contribute to eutrophication and dissolved oxygen depletion. Geopolymer (GP) materials are introduced as sustainable, straightforward operation and low-cost option for pollutant adsorption through ion exchange mechanism. In the present study, a porous metakaolin-based geopolymer with granite waste additions was synthetized, characterised and validated as adsorbent material for NH4+ pollution in water. At this point, treatments to reduce GP alkalis leaching were also considered to comply with the water discharge regulations. The adsorption mechanism was analysed by Redlich-Peterson isotherm model concluding that NH4+ was disposed on the GP surface as a monolayer with strong physical-chemical attraction between molecules. Kinetics of the process followed the Weber-Morris rate equation being the intraparticle diffusion the limiting process. Continuous experiments at lab-scale suggested a maximum removal of 97% during the first hours and an adsorption capacity (q) of 25.24 mg/g. Additionally, as a main novelty of the work, the GP was validated in a full-scale pilot plant monitoring pH, electrical conductivity and NH4+ concentration. The obtained data revealed that the GP is high selective in a real wastewater stream and removed 81% of NH4+, higher adsorption values than those reported for natural and some synthetic zeolites.

Networks of action situations in point-source pollution: the case of winery wastewater in Aragon, Spain

In this article, we offer an analysis of point-source water pollution governance in the European agri-food sector. Specifically, we tackle the case study of the wine industry in Aragon (Spain) through the lenses of the networks of action situations approach. We unveil key strategic decisions of wine producers in relation to compliance with water discharge regulations and explore the feasibility and effectiveness of potential solutions. According to our quantitative and qualitative analyses, the problem of peak load discharges in the sector can be explained by the strategic behavior of wine producers in the context of enforcement deficits, as well as by particularities of the wine production process, and controversies around the construction and management of public treatment plants. Coordination among wine producers and public treatment plant managers to invest in in-house treatment infrastructure or to smooth discharges out so they fit the capacity of treatment plants would be a promising solution; however, economic incentives and tightened enforcement of discharge regulations would also be necessary.Graphical abstract

The food resources exploitation by small-sized fish in a riverine macrophyte habitat

In an altered stretch of the lowland River Warta, central Poland, downstream of the Jeziorsko Reservoir, patches of submersed aquatic macrophytes (SAM) are dependent on water discharge regulations. Such unstable habitat supports abundant epiphytic and benthic macroinvertebrates, and zooplankton flushed out from the reservoir. Patches of vegetation are important for small-sized eurytopic fish as abundant food resources and shelters. We investigated how the abundance and size of prey types constituting the SAM-related food base was partitioned between three fish species, perch Perca fluviatilis, ruffe Gymnocephalus cernua and roach Rutilus rutilus in two vegetation periods of 2004 and 2011, between which SAM differed in area of bed that was overgrown and in biomass. One-way ANOSIM showed that in the larger SAM (in 2004) the diet of roach differed from those of ruffe and perch. SIMPER analysis indicated that average dissimilarity between species was 70.94 ± 9.62%, mainly due to differences in the importance of five prey groups, which contributed nearly 70% to cumulative dissimilarity. The two percid species consumed mainly mid-sized chironomids, while roach fed on plant material, detritus with algae and small-sized chironomids. A different pattern of fish feeding was observed in 2011 when SAM was significantly smaller and food resources were scarcer. Ruffe diet was distinct from both roach and perch diets, though average dissimilarity was smaller, at 69.64 ± 0.84%, and eight food categories contributed over 96% of cumulative dissimilarity, 40% of which by Cladocera alone, which were consumed mainly by perch and roach.

Physicochemical Parameters and Fish Assemblages in the Downstream River of a Tropical Hydroelectric Dam Subjected to Diurnal Changes in Flow

The downstream river of the tropical Batang Ai Dam is experiencing diurnal flow fluctuation due to power generation operation. Three samplings were conducted to collect the water quality and fish assemblage data and one sampling was conducted to study the hydrological characteristics of the downstream river. The results show that the downstream river is extremely shallow and moves slowly when the power generation is halted and no water is discharged from the powerhouse. Significant correlations between river flow and pH, dissolved oxygen (DO), total suspended solids (TSS), and five-day biochemical oxygen demand (BOD5) indicated that those parameters were influenced by the water discharge regulation. Fish abundance was low in upstream segment but it gradually increased as distance from the dam increased and was significantly correlated with DO. Fish diversity in the downstream river was influenced by the river depth and chlorophyll a concentration. The most abundant fish species, Cyclocheilichthys apogon, exhibited a negative allometric growth pattern, while Hampala macrolepidota and Hemibagrus planiceps exhibited an isometric growth pattern. Fulton’s condition factor (K) values for 89.4% of H. planiceps were ≤1, indicating poor to extremely poor conditions.

Biological phosphorus removal from abattoir wastewater at very short sludge ages mediated by novel PAO clade Comamonadaceae

Recent increases in global phosphorus costs, together with the need to remove phosphorus from wastewater to comply with water discharge regulations, make phosphorus recovery from wastewater economically and environmentally attractive. Biological phosphorus (Bio-P) removal process can effectively capture the phosphorus from wastewater and concentrate it in a form that is easily amendable for recovery in contrast to traditional (chemical) phosphorus removal processes. However, Bio-P removal processes have historically been operated at medium to long solids retention times (SRTs, 10–20 days typically), which inherently increases the energy consumption while reducing the recoverable carbon fraction and hence makes it incompatible with the drive towards energy self-sufficient wastewater treatment plants. In this study, a novel high-rate Bio-P removal process has been developed as an energy efficient alternative for phosphorus removal from wastewater through operation at an SRT of less than 4 days. The process was most effective at an SRT of 2–2.5 days, achieving >90% phosphate removal. Further reducing the SRT to 1.7 days resulted in a loss of Bio-P activity. 16S pyrotag sequencing showed the community changed considerably with changes in the SRT, but that Comamonadaceae was consistently abundant when the Bio-P activity was evident. FISH analysis combined with DAPI staining confirmed that bacterial cells of Comamonadaceae arranged in tetrads contained polyphosphate, identifying them as the key polyphosphate accumulating organisms at these low SRT conditions. Overall, this paper demonstrates a novel, high-rate phosphorus removal process that can be effectively integrated with short SRT, energy-efficient carbon removal and recovery processes.

Assessment of didecyldimethylammonium chloride as a ballast water treatment method

Ballast water-mediated transfer of aquatic invasive species is considered a major threat to marine biodiversity, marine industry and human health. A ballast water treatment is needed to comply with International Maritime Organization (IMO) ballast water discharge regulations. Didecyldimethylammonium chloride (DDAC) was tested for its applicability as a ballast water treatment method. The treatment of the marine phytoplankton species Tetraselmis suecica, Isochrysis galbana and Chaetoceros calcitrans showed that at 2.5 µL L−1 DDAC was able to inactivate photosystem II (PSII) efficiency and disintegrate the cells after 5 days of dark incubation. The treatment of natural marine plankton communities with 2.5 µL L−1 DDAC did not sufficiently decrease zooplankton abundance to comply with the IMO D-2 standard. Bivalve larvae showed the highest resistance to DDAC. PSII efficiency was inactivated within 5 days but phytoplankton cells remained intact. Regrowth occurred within 2 days of incubation in the light. However, untreated phytoplankton exposed to residual DDAC showed delayed cell growth and reduced PSII efficiency, indicating residual DDAC toxicity. Natural marine plankton communities treated with 5 µL L−1 DDAC showed sufficient disinfection of zooplankton and inactivation of PSII efficiency. Phytoplankton regrowth was not detected after 9 days of light incubation. Bacteria were initially reduced due to the DDAC treatment but regrowth was observed within 5 days of dark incubation. Residual DDAC remained too high after 5 days to be safely discharged. Two neutralization cycles of 50 mg L−1 bentonite were needed to inactivate residual DDAC upon discharge. The inactivation of residual DDAC may seriously hamper the practical use of DDAC as a ballast water disinfectant.

Solutions for Managing Wastewater in Florida Tomato Packinghouses

A large amount of wastewater is produced in Florida's packinghouses during the cleaning and sanitizing of tomatoes. High transportation costs for off-site disposal and strict surface water discharge regulations are critical issues associated with the management of this wastewater. This 4-page fact sheet provides solutions for increasing the reuse of wastewater in tomato packinghouses in Florida. Written by Gurpal Toor, Maninder Chahal, and Bielinski Santos, and published by the UF Department of Soil and Water Science, August 2012.

Spawning migration of American eel Anguilla rostrata from pristine (1843–1872) to contemporary (1963–1990) periods in the St Lawrence Estuary, Canada

Daily American eel Anguilla rostrata catches and their dates of passage (starting, median and ending dates) were compared between pristine (1843-1872) and contemporary periods (1963-1990) to determine any changes and see whether these were related to environmental variations and water discharge regulation. Timing and duration of A. rostrata migration patterns differed significantly between the two periods. In the contemporary period, migrating A. rostrata were intercepted significantly earlier than in pristine times (18 days earlier on average), and ended at the same average period. Early A. rostrata migration was also significantly related to high spring flow and secondarily to high spring temperature, while migration ended later when high temperature or low water level occurred during the autumn period. A recent slight increase in the water temperature of the St Lawrence River could partially explain the earlier A. rostrata migration observed during the contemporary period. In return, the effect of high spring flow should have been more contrasted if the river discharge would have not been regulated. Recent A. rostrata production now being mainly restricted to the lower part of St Lawrence River mainstream, resulting shorter travelling distance to the estuary may explain why migrating progress was earlier during the contemporary period.

Chemical Characterization of Tomato Industry Wastewater, Florida, United States

Tomato packers often struggle to find ways to reuse the large volumes of wastewater generated during the tomato cleaning and sanitizing processes due to high transportation costs for off-site disposal and strict surface water discharge regulations in Florida. Information about the composition of tomato packinghouse wastewater and the likely sources of major wastewater constituents might provide insights to develop environmentally sustainable practices for wastewater reuse. The objective of this study was to characterize the chemical composition of wastewater generated in tomato packinghouses. The wastewater samples were collected for 6 to 8 hours from dump tanks of two representative packinghouses at 30 minute intervals after start-up of packing operations during May-June 2009. Results showed that wastewater had high electrical conductivity (1.3 - 2.8 dS·m–1) and chloride (255 - 1125 mg·L–1) due to the use of chlorine as a sanitizer in the packinghouses. Concentrations of total phosphorus (P, 2.8 - 5.7 mg·L–1) and copper (Cu, 1.9 - 2.2 mg·L–1) in wastewater were elevated due to tomato cleaning and sanitizing. To reduce P and Cu concentrations, treatment or blending of wastewater may be needed before discharging wastewater to surface waters. Concentrations of P, potassium, calcium, magnesium, zinc, iron, and manganese were much higher in packinghouse 1 as compared to packinghouse 2 wastewater, probably due to the greater contact time of tomatoes with the dump tank water. Whereas concentrations of Cu were similar in both packinghouses wastewater. Greater concentrations of chemical constituents in the wastewater suggest that residues of pesticides, insecticides, and/or foliar-applied micronutrients on tomatoes may be the likely external sources of most constituents (especially P, Cu, and Zn) in wastewater.

Verifying Compliance with Ballast Water Discharge Regulations

U.S. and international rules have been proposed to reduce the risks associated with invasive aquatic organisms by requiring that ships’ ballast water be treated to kill or remove living organisms and achieve certain standards before being discharged. Enforcing these rules requires verifying when a discharge violates these standards. A preliminary comparison of verification systems indicates that mandatory reporting and inspecting treatment equipment do not provide an acceptable level of confidence and that sampling and analyzing enough ballast water to achieve acceptable confidence is prohibitively costly. The most cost-effective alternative that achieves an acceptable level of confidence involves indirect measures of ballast water using sensors that indicate whether discharge standards are met.

Spatial based compromise programming for multiple criteria decision making in land use planning

Today, competing land use is continuing to occur in many developed regions. In the Agricultural Development Zone of Western Sydney Region, which is characterised by complex landscape patterns, land use competition is widespread. From a land use planning perspective, identification of suitable locations for a given type of land use is necessary for decision makers to formulate land use alternatives in different locations, based on existing land potential and constraints. For such a region, use of a simple method that implements a categorical system and considers only inherent land characteristics in the analysis is often inadequate to arrive at an optimal spatial decision. The primary aim of this paper is to develop spatial modelling procedures for agricultural land suitability analysis using compromise programming (CoPr) and fuzzy set approach within a geographical information systems (GIS) environment. Five main sets of spatial data for use as decision criteria were developed by using fuzzy set methodology: a land suitability index (LSI) for maximising the land productivity objective; an erosion tolerance index (ETI) for minimising the erosion risk objective; a runoff curve number (CN) for maximising the water discharge regulation objective; an accessibility (RP) measure for maximising the land accessibility objective; and the proximity to water body (WP) for minimising the water pollution objective. An L p -metric was used in the analysis utilising different strategies with representative indices ranging from a situation where full tradeoff among criteria occurs to a noncompensatory condition. Different weighting combinations were also applied, and decision analysis was carried out by using values ranging from 0 to 1.0, where 1.0 is considered as an ideal point. The CoPr model demonstrated in this paper yielded a promising result, as several different techniques of sensitivity analysis show reasonably good results. Likewise, an overlay of that result with the present land use/land cover indicates a good corresponding spatial matching between existing land use (orchard and cultivated land), and the cells (land parcels) classified as the best in CoPr. The results are amenable to various map display techniques, either using continuous values or by defining different cut off points in the data space within a raster GIS environment.

Multicriteria optimization of landscapes using GIS-based functional assessments

This paper introduces a new way of using GIS to support decision making in the planning process and to develop regional guidelines. The method of `multicriteria optimization' helps new methodological standards to be established for integrating the various results of functional landscape ecology assessments of the type usually carried out in ecological planning, and enables the overall comparison of competing aims. This technique allows different aims in a geographical region to be quantified and takes into account different weightings of scenarios. Different functional assessments (soil erosion hazards caused by water flow, groundwater regeneration, water discharge regulation) and an assessment of the agricultural production function were carried out using GIS for a test site measuring 48 km 2 in a glacial end moraine area to the north of Leipzig (Saxony, Germany). The results were presented in the form of ordinal assessment classes which express tendencies. On the basis of these assessment results, aims for the calculation of an optimal land-use pattern were defined and weighted in different scenarios. Multicriteria optimization calculates optimal compromises with regard to these aims which can be measured and compared with goal function values. Although the method cannot replace decision making by the planner, which is often difficult and can generally not be quantitatively verified, it can help to make the planning process more objective.

BASS STRAIT WATER HANDLING DEVELOPMENTS

Esso Australia Ltd operates, on behalf of Esso/BHP, a crude oil and natural gas producing and processing facility in the Gippsland Basin, Victoria. Saline formation water produced with the oil is treated and discharged overboard from offshore platforms wherever possible to limit the volume of saline water in the pipeline system and avoid onshore disposal of saline water. Esso has developed oily water treatment and continuous oil-in- water monitoring beyond conventional technology and operates within stringent overboard water discharge regulations. Initial oily water treating installations were Cross Flow Interceptors, a corrugated plate gravity separator. Unsatisfactory performance prompted investigations leading to development of the Dissolved Gas Flotation unit using evolved gas to lift oil droplets to the surface. These units operate successfully offshore today. The most recent developments have been associated with a liquid-liquid hydrocyclone trade named 'Vortoil'. This has been tested offshore with an 'Purometer' continuous oil-in-water monitor. The Vortoil and Purometer have both performed favourably and proven a compact, low cost combination for future water treating installations.