It is increasingly recognized that climate change could impose both direct and indirect impacts on the quality of the water environment. Previous studies have mostly concentrated on evaluating the impacts of climate change on non-point source pollution in agricultural watersheds. Few studies have assessed the impacts of climate change on the water quality of river basins with complex point and non-point pollution sources. In view of the gap, this paper aims to establish a framework for stochastic assessment of the sensitivity of water quality to future climate change in a river basin with complex pollution sources. A sub-daily soil and water assessment tool (SWAT) model was developed to simulate the discharge, transport, and transformation of nitrogen from multiple point and non-point pollution sources in the upper Huai River basin of China. A weather generator was used to produce 50 years of synthetic daily weather data series for all 25 combinations of precipitation (changes by − 10, 0, 10, 20, and 30%) and temperature change (increases by 0, 1, 2, 3, and 4 °C) scenarios. The generated daily rainfall series was disaggregated into the hourly scale and then used to drive the sub-daily SWAT model to simulate the nitrogen cycle under different climate change scenarios. Our results in the study region have indicated that (1) both total nitrogen (TN) loads and concentrations are insensitive to temperature change; (2) TN loads are highly sensitive to precipitation change, while TN concentrations are moderately sensitive; (3) the impacts of climate change on TN concentrations are more spatiotemporally variable than its impacts on TN loads; and (4) wide distributions of TN loads and TN concentrations under individual climate change scenario illustrate the important role of climatic variability in affecting water quality conditions. In summary, the large variability in SWAT simulation results within and between each climate change scenario highlights the uncertainty of the impacts of climate change and the need to incorporate extreme conditions in managing water environment and developing climate change adaptation and mitigation strategies.

Dibutyl phthalate is an important phthalate ester extensively used in various products like plastics, adhesives, inks, pharmaceuticals, lacquers, varnishes, paper coatings, safety glasses, and cosmetics. The exposure of DBP to “one’s health” is therefore inevitable. The present study focuses on elucidating the effect of low doses of DBP on anthropometric parameters and markers of obesity in rats in a 13-week study. A total of 48 rats were divided into three treatment groups as mg DBP/kg body weight per day: (a) 0 mg/kg (control), (b) 10 mg/kg (DBP-10), and (c) 50 mg/kg (DBP-50). The rats in each treatment (n = 16) were further equally divided into male and female rats for studying treatment and gender interaction. Anthropometric parameters, nutritional determinants, and markers of obesity in rats were studied. Two-way ANOVA was used to analyze the data (p < 0.05). Tukey’s post hoc test was used for pairwise comparisons. DBP increased body weight gain, feed efficiency, abdominal to thoracic circumference ratio, and body mass index in rats. Serum cholesterol and alkaline phosphatase concentrations decreased with DBP treatment. Serum albumin, glucose, creatinine, and alanine transaminase increased with DBP treatments. Serum lactate dehydrogenase increased in DBP-10 but was not affected by DBP-50. Further low-dose investigations are needed to assess non-monotonic dose responses.

Saffron is regarded as an important crop in Iranian agricultural economics that needs to be investigated to produce the environmentally friendlier product. In the present study, saffron production as an important agricultural production system in Iran was evaluated thoroughly from an environmental point of view. Data were collected from saffron farmers in Southern Khorasan province of the country with face-to-face questionnaire method during cropping period of 2013–2014. The system boundary was considered from the production of raw input materials to the harvested saffron. In order to identify the main hotspot during cultivation, impact categories were considered using CML methodology and cumulative exergy demand (CExD) indicator. Based on the results, chemical fertilizers N and P were the main hotspots in abiotic depletion (AD), acidification (AC), global warming (GWP), and photochemical oxidation (PO) impact categories, while diesel fuel was the main hotspot in fresh water aquatic ecotoxicity (FE), marine aquatic ecotoxicity (ME), and terrestrial ecotoxicity (TE). Direct emission from diesel fuel combustion (saffron) was the main hotspot only in human toxicity (HT). The small farms had the highest amounts of AD, AC, EP, GWP, and PO indicators in comparison with the medium and large farms. Total CExD indicator for production of 1 kg saffron was 1894.23 MJ eq. Totally, large farms (bigger than 1 ha) had better environmental performance considering all the impact categories.

Occurrence of 10 antibiotics in the Yuen Long (YLR), Kam Tin (KTR), and Shing Mun (SMR) rivers of Hong Kong and possible influence of livestock activities on the concentrations of antibiotics were investigated. Tetracycline (30–497 ng/L), sulfadiazine (2–80 ng/L), sulfamethoxazole (2–152 ng/L), ofloxacin (5–227 ng/L), and erythromycin (1–315 ng/L) were detected in all the three rivers; chlortetracycline (23–227 ng/L), oxytetracycline (7–104 ng/L), ciprofloxacin (12–68 ng/L), and roxithromycin (1–105 ng/L) were detected in YLR and KTR, whereas norfloxacin (3–34 ng/L) was detected in KTR only. Significant correlation between livestock population and antibiotic contamination was observed in YLR only, indicating the influences of other sources in KTR and SMR. Among the antibiotics, significant correlation was observed between tetracyclines and sulfonamides indicating the major influence of livestock farms, whereas tetracyclines/sulfonamides were negatively correlated with fluoroquinolones/macrolides implying the differential origin of the latter class of antibiotics. Water quality of KTR and YLR were highly influenced by the non-point source pollutions, while of SMR was relatively good. Particularly, Escherichia coli populations of the YLR and KTR were 3–4 logs higher than those of the SMR indicating the involvement of livestock farms and sewerages. Good correlation between tetracyclines (TCs)/sulfonamides (SAs) and number of livestock farms and a negative correlation between TCs/SAs and fluoroquinolones (FQs)/macrolides (MLs) could be used as an indicator to trace the possible source of pollution.

In order to have an extensive contamination profile of heavy metal levels (Cd, Cu, Fe, Mn, Ni, Pb, and Zn), seawater, sediment, Patella caerulea, Cystoseira barbata, and Liza aurata were investigated by using inductively coupled plasma-atomic emission spectrometry (ICP-AES). Samples were collected from five coastal stations along the eastern Aegean Sea coast (Turkey) on a monthly basis from July 2002 through May 2003. According to the results of this study, heavy metal levels were arranged in the following sequence: Fe > Pb > Zn > Mn > Ni > Cu > Cd for water, Fe > Cu > Mn > Ni > Zn > Pb > Cd for sediment, Fe > Zn > Mn > Pb > Ni > Cd > Cu for C. barbata, Fe > Zn > Mn > Ni > Pb > Cu > Cd for P. caerulea, and Fe > Zn > Mn > Cu > Ni > Pb > Cd for L. aurata. Moreover, positive relationships between Fe in water and Mn in water, Fe in sediment and Mn in sediment, Fe in C. barbata and Mn in C. barbata, Fe in P. caerulea and Mn in P. caerulea, and Fe in L. aurata and Mn in L. aurata may suggest that these metals could be originated from the same anthropogenic source. C. barbata represented with higher bioconcentration factor (BCF) values, especially for Fe, Mn, and Zn values. This observation may support that C. barbata can be used as an indicator species for the determinations of Fe, Mn, and Zn levels. Regarding Turkish Food Codex Regulation’s residue limits, metal values in L. aurata were found to be lower than the maximum permissible levels issued by Turkish legislation and also the recommended limits set by FAO/WHO guidelines. The results of the investigation indicated that P. caerulea, L. aurata, and especially C. barbata are quantitative water-quality bioindicators and biomonitoring subjects for biologically available metal accumulation for Aegean Sea coastal waters.

This study determined the susceptibility of cultured soil microorganisms to the effects of Ekodiesel Ultra fuel (DO), to the enzymatic activity of soil and to soil contamination with PAHs. Studies into the effects of any type of oil products on reactions taking place in soil are necessary as particular fuels not only differ in the chemical composition of oil products but also in the composition of various fuel improvers and antimicrobial fuel additives. The subjects of the study included loamy sand and sandy loam which, in their natural state, have been classified into the soil subtype 3.1.1 Endocalcaric Cambisols. The soil was contaminated with the DO in amounts of 0, 5 and 10 cm³ kg⁻¹. Differences were noted in the resistance of particular groups or genera of microorganisms to DO contamination in loamy sand (LS) and sandy loam (SL). In loamy sand and sandy loam, the most resistant microorganisms were oligotrophic spore-forming bacteria. The resistance of microorganisms to DO contamination was greater in LS than in SL. It decreased with the duration of exposure of microorganisms to the effects of DO. The factor of impact (IFDO) on the activity of particular enzymes varied. For dehydrogenases, urease, arylsulphatase and β-glucosidase, it had negative values, while for catalase, it had positive values and was close to 0 for acid phosphatase and alkaline phosphatase. However, in both soils, the noted index of biochemical activity of soil (BA) decreased with the increase in DO contamination. In addition, a positive correlation occurred between the degree of soil contamination and its PAH content.

The heterogeneous catalytic degradation of a model azo dye, acid red 1 (AR1), initiated by zero valent iron nanoparticles (ZVINP), and its synergic effect with ultrasound (US) have been investigated in the present study. The treatment of AR1 using ZVINP at pH 3 showed maximum efficiency in terms of colour removal (53.0%) and mineralization (48.5% TOC reduction) after 25 min of reaction. However, the coupling of this system with US showed an enhanced efficiency against the decolourization and mineralization of AR1. More than 95% colour removal was achieved within 5 min in the case of US/ZVINP system. Around 55% TOC reduction suggests the conversion of the parent molecules in to aromatic transformed products, and it is further supported by LC-Q-TOF analysis. The remarkably higher efficiency in the coupled system is attributed to the synergic effect of ZVINPs and ultrasound. The highest degradation rates observed at highly acidic (pH 3) and alkaline pH (pH 9) suggests that different mechanisms are operating at both pH. The products identified gave some insight into the mechanism. The ZVINPs prepared in the present study was easily recoverable (and reusable) and hence may be considered as an effective replacement for the conventional Fenton’s reagent.

Odorants from municipal solid waste (MSW) were complex variable, and the screening of key offensive odorants was the prerequisite for odor control process. In this study, spatial odor emissions and environmental impacts were investigated based on a large-scale working waste transfer station (LSWTS) using waste container system, and a comprehensive odor characterization method was developed and applied in terms of the odor concentration (OC), theory odor concentration (TOC), total chemical concentration (TCC), and electric nose (EN). The detected odor concentration ranged from 14 to 28 (dimensionless), and MSW container showed the highest OC value of 28, EN of 78, and TCC of 35 (ppm) due to the accumulation of leachate and residual MSW. Ninety-two species odorants were identified, and H₂S, NH₃, benzene, styrene, ethyl acetate, and dichloromethane were the main contributors in the container, while benzene, m,p,x-xylene, butanone, acetone, isopropanol, and ethyl acetate were predominant in the compression surface (CS) and compression plant (CP). Side of roads (SR) and unload hall (UH) showed low odorous impact. Based on this odor list, 20 species of odor substances were screened for the priority control through the synthetic evaluation method, considering the odorants concentrations, toxicity, threshold values, detection frequency, saturated vapor pressure, and appeared frequency. Graphical abstract

In this paper, the possibility of reusing textile effluents for new dyeing baths has been investigated. For this purpose, different trichromies using Direct Red 80, Direct Blue 106, and Direct Yellow 98 on cotton have been used. Effluents have been treated by means of a photo-Fenton process at pH 5. Addition of humic-like substances isolated form urban wastes is necessary in order to prevent iron deactivation because of the formation of non-active iron hydroxides. Laboratory-scale experiments carried out with synthetic effluents show that comparable results were obtained when using as solvent water treated by photo-Fenton with SBO and fresh deionized water. Experiments were scaled up to pilot plant illuminated under sunlight, using in this case a real textile effluent. Decoloration of the effluent could be achieved after moderate irradiation and cotton dyed with this water presented similar characteristics as when deionized water was used.