The soybean processing wastewater (SPW) supplementation to facilitate the simultaneously treatment (SPW and mesosulfuron-methyl) of wastewater and production of biological substances by Rhodopseudomonas sphaeroides (R. sphaeroides) was discussed. Compared with the control group, with the addition of SPW, mesosulfuron-methyl was removed, and the yields of single-cell proteins, carotenoids, and bacteriochlorophyll were increased. In the 3 mg/L dose group, the mesosulfuron-methyl removal rate reached 97% after 5 days. Molecular analysis revealed that mesosulfuron-methyl exhibited induction effects on expression of the cpm gene and regulation effects on the synthesis of cytochrome P450 monooxygenases (P450) by activating HKs gene in TCS signal transduction pathway. For R. sphaeroides, this induction process required 1 day. The synthesis of P450 occurred 1 day after inoculation. Prior to expressing cpm gene and synthesizing P450, R. sphaeroides need a period of time to adapt to external mesosulfuron-methyl stimulation. However, the R. sphaeroides growth could not be maintained for more than 1 day due to the lack of organic matter in the raw wastewater. The SPW supplementation provided a sufficient carbon source in four groups with added SPW. After 5 days, R. sphaeroides became the dominant microflora in the wastewater. This new method could complete the treatment of mixed wastewater, the increased of biological substances output and the reuse of wastewater and R. sphaeroides cells as resources at the same time.

Increasing interest of seeking substitutable water resources accrues from shortage of freshwater. One of the options considered is reclaimed water (also designated as recycled water) that has been widely used in daily life. Although reclaimed water can serve as a feasible reliever of water pressure, attention about its technologies and potential risks is growing in the meantime. Most established wastewater treatment plants (WWTPs) predate many new contaminants, which means treatment processes cannot ensure to dislodge certain contaminants completely from origin water. Furthermore, a wide range of factors, such as seasons and influent variations, affect occurrence and concentration of reclaimed water-borne contaminants, making research about quality of reclaimed water especially significant. Many reclaimed water-borne contaminants, including biological and chemical contaminants, are toxic to human health, and complex wastewater matrix may aggravate water quality of concern. The widespread use of reclaimed water continues to be a concern on agriculture, ecological environment and human health. This study aims to: 1) provide a critical review about occurrence and profiles of diverse contaminants in the treated reclaimed water, 2) discuss the possibility to avoid the secondary pollution in reuse of reclaimed water, and 3) reveal the prospective consequences of using reclaimed water on agriculture, ecological environment and human health.

Acid mine drainage (AMD) is a global environmental issue. Conventionally, a number of active and passive remediation approaches are applied to treat and manage AMD. Case studies on remediation approaches applied in actual mining sites such as lime neutralization, bioremediation, wetlands and permeable reactive barriers provide an outlook on actual long-term implications of AMD remediation. Hence, in spite of available remediation approaches, AMD treatment remains a challenge. The need for sustainable AMD treatment approaches has led to much focus on water reuse and resource recovery. This review underscores (i) characteristics and implication of AMD, (ii) remediation approaches in mining sites, (iii) alternative treatment technologies for water reuse, and (iv) resource recovery. Specifically, the role of membrane processes and alternative treatment technologies to produce water for reuse from AMD is highlighted. Although membrane processes are favorable for water reuse, they cannot achieve resource recovery, specifically selective valuable metal recovery. The approach of integrated membrane and conventional treatment processes are especially promising for attaining both water reuse and recovery of resources such as sulfuric acid, metals and rare earth elements. Overall, this review provides insights in establishing reuse and resource recovery as the holistic approach towards sustainable AMD treatment. Finally, integrated technologies that deserve in depth future exploration is highlighted.

Occurrence and removal of 81 representative Pharmaceutical Active Compounds (PhACs) were assessed in a municipal WWTP located in a highly industrialized area, with partial water reuse after UV tertiary treatment and discharge to a Mediterranean river. Water monitoring was performed in an integrated way at different points in the WWTP and river along three seasons.Consistent differences between therapeutic classes were observed in terms of influent concentration, removal efficiencies and seasonal variation. Conventional (primary and secondary) treatment was unable to completely remove numerous compounds and UV-based tertiary treatment played a complementary role for some of them. Industrial activity influence was highlighted in terms of PhACs presence and seasonal distribution.Even if global WWTP effluent impact on the studied river appeared to be minor, PhACs resulted widespread pollutants in river waters. Contamination can be particularly critical in summer in water scarcity areas, when water flow decreases considerably.

The long-term ecological risk of micropollutants, especially endocrine disrupting chemicals (EDCs) has threatened reclaimed water quality. In this study, estrogenic activity and ecological risk of eight typical estrogenic EDCs in effluents from sewage plants were evaluated. The estrogenic activity analysis showed that steroidal estrogens had the highest estrogenic activity (ranged from 10−1 to 103 ng-E2/L), phenolic compounds showed weaker estrogenic activity (mainly ranged from 10−3 to 10 ng-E2/L), and phthalate esters were negligible. The ecological risk of the estrogenic EDCs which was characterized by risk quotient ranged from 10−4 to 103, with an order in descending: steroids estrogens, phenolic compounds and phthalate esters. The eight estrogenic EDCs were scored and sorted based on the comparison of the estrogenic activity and the ecological risk, suggesting that 17α-ethynylestradiol (EE2), estrone (E1) and estradiol (E2) should be the priority EDCs to control in municipal sewage plants.

Wastewater reclamation and reuse for agriculture have attracted a great deal of interest, due to water stress caused by rapid increase in human population and agricultural water demand as well as climate change. However, the application of treated wastewater for irrigation can lead to the accumulation of pharmaceuticals and personal care products (PPCPs) in the agricultural crops, grazing animals, and consequently to human dietary exposure. In this study, a model was developed to simulate the fate of five PPCPs; triclosan (TCS), carbamazepine (CBZ), naproxen (NPX), gemfibrozil (GFB), and fluoxetine (FXT) during wastewater reuse for agriculture, and potential human dietary exposure and health risk. In a reclaimed wastewater-irrigated grazing farm growing alfalfa, it took 100–535 days for PPCPs to achieve the steady-state concentrations of 1.43 × 10⁻⁶, 4.73 × 10⁻⁵, 1.17 × 10⁻⁶, 1.53 × 10⁻⁵, and 7.38 × 10⁻⁶ mg/kg for TCS, CBZ, NPX, GFB, and FXT in soils, respectively. The accumulated concentration of PPCPs in the plant (alfalfa) and grazing animals (beef) ranged 2.86 × 10⁻⁷− 4.02 × 10⁻³ and 4.39 × 10⁻¹⁵− 6.27 × 10⁻⁷ mg/kg, respectively. Human dietary exposure to these compounds through beef consumption was calculated to be 1.67 × 10⁻¹⁸− 1.74 × 10⁻¹⁰ mg/kg bodyweight/d, much lower than the acceptable daily intake (ADI). Similar results were obtained for a ‘typical’ reclaimed wastewater irrigated farm based on the typical setup using our model. Screening analysis showed that PPCPs with relatively high LogD value and lower ratios of degradation rate (in soils) to plant uptake have a greater potential to be transferred to humans and cause potential health risks. We established a modeling method for evaluating the fate and human health effects of PPCPs in reclaimed wastewater reuse for the agricultural system and developed an index for screening PPCPs with high potential to accumulate in agricultural products. The model and findings are valuable for managing water reuse for irrigation and mitigating the harmful effects of PPCPs.

With increasing population growth and climate change, de facto reuse practices are predicted to increase globally. We investigated a longitudinal gradient within the Uhlava River, a representative watershed, where de facto reuse is actively occurring, during Fall and Spring seasons when instream flows vary. We observed human pharmaceutical levels in the river to continuously increase from the mountainous areas upstream to downstream locations and a potable intake location, with the highest concentrations found in small tributaries. Significant relationship was identified between mass flow of pharmaceuticals and the size of human populations contributing to wastewater treatment plant discharges. Advanced ozonation and granular activated carbon filtration effectively removed pharmaceuticals from potable source waters. We observed a higher probability of encountering a number of targeted pharmaceuticals during colder Spring months when stream flows were elevated compared to warmer conditions with lower flows in the Fall despite a dilution paradigm routinely applied for surface water quality assessment and management efforts. Such observations translated to greater water quality hazards during these higher Spring flows. Future water monitoring efforts should account for periods when higher chemical uses occur, particularly in the face of climate change for regions experiencing population growth and de facto reuse.

In respect to direct and indirect water reuse, the microbiological quality of treated wastewater is highly important. Conventional wastewater treatment plants are normally not equipped with advanced technologies for the elimination of bacteria. Molecular biology analyses were combined with live-dead discrimination analysis of wastewater population using Propidium monoazide (PMA) to study population shifts during ozonation (1 g ozone/g DOC) at a municipal wastewater treatment plant. Escherichia coli, enterococci, and Pseudomonas aeruginosa were quantified by polymerase chain reaction (qPCR) and the whole wastewater population was analyzed by metagenomic sequencing. The PMA-qPCR experiments showed that the abundances of P. aeruginosa didn't change by ozone treatment, whereas a reduction was observed for E. coli and enterococci. Results comparing conventional cultivation experiments with PMA-qPCR underlined the presence of viable but not culturable cells (VBNC) and their regrowth potential after ozone treatment. Illumina HiSeq sequencing results with and without PMA treatment demonstrated high population similarities in water samples originating from ozone inflow sampling sides. Upon using PMA treatment after ozonation, population shifts became visible and also underlined the importance of PMA treatment for the evaluation of elimination and selection processes during ozonation at WWTPs. Amongst a number of 14 most abundant genera identified in the inflow samples, 9 genera were found to be reduced, whereas 4 genera increased in relative abundance and 1 genus almost remained constant. The strongest increase in relative abundance after ozonation was detected for Oscillatoria spp., Microcoleus spp. and Nitrospira spp. Beside this, a continuous release of Pseudomonas spp. (including P. aeruginosa) to the downstream receiving body was confirmed. Regrowth experiments demonstrated a high prevalence of P. aeruginosa as part of the surviving bacterial population. Summing up, molecular biology analyses in combination with live-dead discrimination are comprehensive methods to evaluate the elimination processes targeting specific species and/or whole microbial populations.

The reuse of treated wastewater for agricultural irrigation in arid and hot climates where plant transpiration is high may affect plant accumulation of pharmaceutical and personal care products (PPCPs) and endocrine disrupting chemicals (EDCs). In this study, carrot, lettuce, and tomato plants were grown in solution containing 16 PPCP/EDCs in either a cool-humid or a warm-dry environment. Leaf bioconcentration factors (BCF) were positively correlated with transpiration for chemical groups of different ionized states (p < 0.05). However, root BCFs were correlated with transpiration only for neutral PPCP/EDCs (p < 0.05). Neutral and cationic PPCP/EDCs showed similar accumulation, while anionic PPCP/EDCs had significantly higher accumulation in roots and significantly lower accumulation in leaves (p < 0.05). Results show that plant transpiration may play a significant role in the uptake and translocation of PPCP/EDCs, which may have a pronounced effect in arid and hot climates where irrigation with treated wastewater is common.

This study was conducted to determine the uptake of trace elements by the emergent wetland plant species Eleocharis equisetina at the historic Jumna tin processing plant, tropical Australia. The perennial emergent sedge was found growing in acid waters (pH 2.45) and metal-rich tailings (SnAsCuPbZn). E. equisetina displayed a pronounced acid tolerance and tendency to exclude environmentally significant elements (Al, As, Cd, Ce, Co, Cu, Fe, La, Ni, Pb, Se, Th, U, Y, Zn) from its above-substrate biomass. This study demonstrates that geobotanical and biogeochemical examinations of wetland plants at abandoned mined lands of tropical areas can reveal pioneering, metal-excluding macrophytes. Such aquatic macrophytes are of potential use in the remediation of acid mine waters and sulfidic tailings and the reclamation of disturbed acid sulfate soils in subtropical and tropical regions.