Developing and financing new water facilities: Alternatives for desalination and reclamation plants

This report summarizes the Lawrence Berkeley National Laboratory?s research to date in characterizing energy efficiency and automated demand response opportunities for wastewater treatment facilities in California. The report describes the characteristics of wastewater treatment facilities, the nature of the wastewater stream, energy use and demand, as well as details of the wastewater treatment process. It also discusses control systems and energy efficiency and automated demand response opportunities. In addition, several energy efficiency and load management case studies are provided for wastewater treatment facilities.This study shows that wastewater treatment facilities can be excellent candidates for open automated demand response and that facilities which have implemented energy efficiency measures and have centralized control systems are well-suited to shift or shed electrical loads in response to financial incentives, utility bill savings, and/or opportunities to enhance reliability of service. Control technologies installed for energy efficiency and load management purposes can often be adapted for automated demand response at little additional cost. These improved controls may prepare facilities to be more receptive to open automated demand response due to both increased confidence in the opportunities for controlling energy cost/use and access to the real-time data.

This case study enhances the understanding of open automated demand response opportunities in municipal wastewater treatment facilities. The report summarizes the findings of a 100 day submetering project at the San Luis Rey Wastewater Treatment Plant, a municipal wastewater treatment facility in Oceanside, California. The report reveals that key energy-intensive equipment such as pumps and centrifuges can be targeted for large load reductions. Demand response tests on the effluent pumps resulted a 300 kW load reduction and tests on centrifuges resulted in a 40 kW load reduction. Although tests on the facility?s blowers resulted in peak period load reductions of 78 kW sharp, short-lived increases in the turbidity of the wastewater effluent were experienced within 24 hours of the test. The results of these tests, which were conducted on blowers without variable speed drive capability, would not be acceptable and warrant further study. This study finds that wastewater treatment facilities have significant open automated demand response potential. However, limiting factors to implementing demand response are the reaction of effluent turbidity to reduced aeration load, along with the cogeneration capabilities of municipal facilities, including existing power purchase agreements and utility receptiveness to purchasing electricity from cogeneration facilities.

This report details a study into the demand response potential of a large wastewater treatment facility in San Francisco. Previous research had identified wastewater treatment facilities as good candidates for demand response and automated demand response, and this study was conducted to investigate facility attributes that are conducive to demand response or which hinder its implementation. One years' worth of operational data were collected from the facility's control system, submetered process equipment, utility electricity demand records, and governmental weather stations. These data were analyzed to determine factors which affected facility power demand and demand response capabilities The average baseline demand at the Southeast facility was approximately 4 MW. During the rainy season (October-March) the facility treated 40% more wastewater than the dry season, but demand only increased by 4%. Submetering of the facility's lift pumps and centrifuges predicted load shifts capabilities of 154 kW and 86 kW, respectively, with large lift pump shifts in the rainy season. Analysis of demand data during maintenance events confirmed the magnitude of these possible load shifts, and indicated other areas of the facility with demand response potential. Load sheds were seen to be possible by shutting down a portion of the facility's aeration trains (average shed of 132 kW). Load shifts were seen to be possible by shifting operation of centrifuges, the gravity belt thickener, lift pumps, and external pump stations These load shifts were made possible by the storage capabilities of the facility and of the city's sewer system. Large load reductions (an average of 2,065 kW) were seen from operating the cogeneration unit, but normal practice is continuous operation, precluding its use for demand response. The study also identified potential demand response opportunities that warrant further study: modulating variable-demand aeration loads, shifting operation of sludge-processing equipment besides centrifuges, and utilizing schedulable self-generation.

THE reclamation of sewage water has been practised for many years. Indeed, the process has been called as old as sewage disposal itself.' Cesspools and septic tanks have returned sewage effluents to the soil for centuries. Sewage farms and farms utilizing sewage effluents have done likewise, but with more concern for the public health problems involved. This type of reclamation has been termed incidental, since the reclamation of water is incidental to the disposal of sewage.1-3 Planned reclamation, as distinct from incidental reclamation, is a more recent development. It is designed specifically to produce a usable water from sewage. Not only may water be produced for use in industry 4 and agriculture,5 but it may also be returned to the ground water by means of surface spreading or injection wells. In water shortage areas where large quantities of sewage are now being discharged to the ocean, planned reclamation is receiving serious consideration, since it may relieve the overdraft on local water resources more economically than the importing of water from distant places or the distilling of sea water. Surface spreading operations, commonly used for replenishing the ground water, may be conducted on cultivated land requiring irrigation or on uncropped land. On irrigated land such as

Effects of reclaimed wastewater irrigation on soil-crop systems in China: A review

Intake-to-delivered-energy ratios for central station and distributed electricity generation in California

Coupling biogas upgrading and carbon capture and utilization for enhanced environmental performance of water reclamation plants

Conjunctive use of reclaimed water and groundwater in crop rotations

Namibia is the driest sub-Saharan country in Africa. Namibia’s capital, Windhoek, reclaims sewage water for domestic use at the Goreangab Water Reclamation Plant (GWRP). Risks associated with sewage effluent and reclaimed sewage should be closely monitored; therefore water at the Gammams Sewage Treatment Plant (GSTP) inlet and outlet, as well as reclaimed water from the GWRP, were assayed using selected bioassays. Samples collected were analysed using enzyme-linked immunosorbent-assays and chromogenic tests for steroid hormones, neurotoxicity, cytotoxicity and inflammatory activity. Estradiol level at the sewage treatment inlet was 78 pg/mℓ and the treated sewage level showed an 83% to 95% reduction in this, while after reclamation the level was below detection limit. Estrone concentrations at the sewage treatment inlet ranged from 10 to 161 pg/mℓ. Sewage treatment reduced estrone by between 85% and 92%. After reclamation the level of estrone was below detection limit. Testosterone ranged between 162 and 405 pg/mℓ at the sewage plant inlet. Sewage treatment removed 96% of the initial testosterone. The residual testosterone was effectively removed by processes in GWRP and after reclamation no testosterone was detected in water. Acetylcholinesterase (AChE) inhibition at the sewage treatment inlet was 50% while it was only 27% after sewage treatment. After reclamation AChE inhibition was not detected. Only water at the sewage inlet in March and February showed cytotoxicity. High inflammatory activity was detected at the sewage plant inlet. Sewage treatment reduced inflammatory activity by 64%. After reclamation low inflammatory activity was induced. Treated sewage used for reclamation tested positive for most of the biomarkers and can pose a risk to human health. However, reclamation successfully removed these contaminants. Due to the presence of contaminants in the intake water at the reclamation plant, it is essential to routinely monitor the water produced by the reclamation plant for potential residues that can adversely affect human health.Keywords: Endocrine disrupting potential, cytotoxicity, neurotoxicity, inflammatory response, steroid hormones, water quality

The effect on the morpho-physiological parameters and yield of sorghum cultivated in a greenhouse with reclaimed water (RW) and (dehydrated sludge (DS) obtained in a sewage treatment plant, was evaluated. Six treatments (T), with five repetitions each, were carried out in entirely randomized blocks. Water (W) was used in T1 (W) (control), T2 (W + NPK), and T3 (W + DS); RW was used in T4 (RW), T5 (RW + P), and T6 (RW + DS). The results showed that irrigation with only RW (T4), or W + DS (T3) was very suitable for the cultivation since an adequate nutritional supply was provided. The positive effects on the morpho-physiological parameters, plant height, stem diameter and stem length (in cm), were: T3 – 148.8, 1.50, and 103, respectively; T4 – 154, 1.70, and 107, respectively; and on the grain production in weight of 1000 seeds (g), and productivity in grains per plant: T3 – 6.97 and 1453, respectively; T4 – 6.81 and 1636, respectively. Both treatments showed for most of the parameters, no significant differences compared with those of T2 or T5 with supplementary fertilizers. A high production of metabolites (mg g–1) like free amino acids was also shown: T3 – 6.45; T4 – 8.43 and proline: T3 – 1.86; T4 – 1.77, known to be a good indication of a plant natural defence against stress conditions, and in soluble protein: T3 – 11.20; T4 – 13.51. Therefore, since the production of such grains with RW or DS can be environmentally and economically beneficial, their use is recommended for small and medium farmers in semiarid regions.

Large-scale electrolytic H2 production requires a stable electricity supply, sustainable water availability, and proximity to the H2 end-user. However, these elements often exhibit spatiotemporal mismatches in China. Reclaimed water, an unconventional water resource generated by municipal wastewater treatment plants, is widely distributed across China. This study conducted a life-cycle assessment of H2 production from reclaimed water in China, focusing on potential capacity, cost, and carbon emissions. The results were compared with those using tap water and seawater. Even when prioritized for ecological and municipal reuse, reclaimed water demonstrated significant H2 production capacity (95.7-213.1 Mt/year between 2021 and 2060), attributable to its proximity to critical resources and H2 markets. This capacity could meet China's annual H2 demand (33.4-130.9 Mt/year) while achieving provincial self-sufficiency. By contrast, H2 production capacity using tap water and seawater is substantially lower (19.8-79.1 Mt/year). Currently, H2 production from reclaimed water exhibits cost and carbon emissions comparable to those of conventional electrolytic routes. However, advancements in electrolyzer efficiency and grid decarbonization could reduce these metrics to 4.0 ± 0.5 USD/kg H2 and 4.99 ± 0.05 kg CO2-eq/kg H2 by 2050, making it competitive with fossil-derived H2 (∼4.3 USD/kg H2) while meeting green H2 threshold (∼4.9 kg CO2-eq/kg H2).

Due to continual deterioration of surface water quality and increased water scarcity, water reclamation of the treated effluent has become a widely accepted strategy for sustainable water supply in urban areas. Reverse osmosis (RO) is a reliable and essential water reclamation technology for producing high-quality water for reuse. The RO concentrate, which is the waste stream produced from the RO process, is volumetrically substantial and contains environmentally harmful substances and therefore can cause severe environmental impacts if disposed of to receiving water bodies. Several technologies are available for further treatment of RO concentrate to reduce its volume, remove its total dissolved solids (TDS) and total organic carbon (TOC) and reclaim it for additional water recovery. This chapter presents a review of RO concentrate quality and various technologies for treating RO concentrate originated from municipal wastewater treatment plant. The technologies discussed include mineral recovery, electrochemical desalting and removal of TOC through adsorption, coagulation and oxidative degradation. Other alternative strategies including the emerging technologies for increasing water recovery rate from water reclamation plant are also proposed.

Reclaimed wastewater (RWW) has been used globally for centuries, though its application in aquaculture is less extensive. Limited study has addressed impacts of RWW-derived volatile odour compounds (VOCs), such as 2,4,6-trichloroanisole (TCA), 2-methylisoborneol (MIB), and geosmin (GSM), on fish quality. This study aims to (1) assess the feasibility of reusing secondary effluent from a municipal wastewater treatment plant (WWTP) for Plecoglossus altivelis aquaculture in a land-based flow-through system and (2) evaluate the sensory effects of selected VOCs on fish quality. Results showed that increased temperature and ammonia levels in summer RWW negatively affected fish growth, while autumn RWW did not. Heavy metals in fish did not cause health issues. TCA, MIB, and GSM concentrations in fish tissues were 4.7–5.7, 0.3–40.5, and 1.1–1.9 mg kg−1, respectively. TCA emerged as the most concerning odorant, with higher relative odour intensity than MIB and GSM in RWW-cultured fish, regardless of seasonal change. This study is the first to report on a self-constructed aquaculture system using RWW at a WWTP, recommending effective VOC and ammonia removal for sustainable RWW use in aquaculture. Additionally, the study highlighted TCA's impact as an anthropogenic indicator in aquatic environments amid increasing WWTP prevalence in developed cities.

Risk assessment of contaminants of emerging concern in the context of wastewater reuse for irrigation: An integrated modelling approach.

Since 1982, there has been a major effort expended to evaluate the susceptibility of nuclear Power plant equipment to failure and significant damage during seismic events. This was done by making use of data on the performance of electrical and mechanical equipment in conventional power plants and other similar industrial facilities during strong motion earthquakes. This report is intended as an extension of the seismic experience data collection effort and a compilation of experience data specific to power plant piping and supports designed and constructed US power piping code requirements which have experienced strong motion earthquakes. Eight damaging (Richter Magnitude 7.7 to 5.5) California earthquakes and their effects on 8 power generating facilities in use natural gas and California were reviewed. All of these facilities were visited and evaluated. Seven fossel-fueled (dual use natural gas and oil) and one nuclear fueled plants consisting of a total of 36 individual boiler or reactor units were investigated. Peak horizontal ground accelerations that either had been recorded on site at these facilities or were considered applicable to these power plants on the basis of nearby recordings ranged between 0.20g and 0.5lg with strong motion durations which varied from 3.5 to 15 seconds. Most US nuclear power plants are designed for a safe shutdown earthquake peak ground acceleration equal to 0.20g or less with strong motion durations which vary from 10 to 15 seconds.