Dyes are widely used in many industrial sectors, many contain harmful substances to human health, and their release into the environment entails several environmental problems, generating a major worldwide concern as water resources are increasingly limited. The development of cheap and efficient biosorbents that remove these pollutants is of utmost importance. In this study, powdered seeds of the araticum fruit (Annona crassiflora) were used in the biosorption of crystal violet (CV) dye from aqueous solutions and simulated textile effluents. Through the characterization techniques, it can be observed that the material presented an amorphous structure, containing an irregular surface composed mainly by groups containing carbon, hydrogen, and oxygen. CV biosorption was favored at the natural pH of the solution (7.5) for a dosage of 0.7 g L⁻¹ of araticum seed powder. The pseudo-second-order model was the most suitable to represent the biosorption kinetics in the removal of the CV. Biosorption capacity reached equilibrium in the first minutes at the lowest concentrations, and, at the highest, after 120 min. The equilibrium data were well represented by the Langmuir model, with a maximum biosorption capacity of 300.96 mg g⁻¹ at 328 K. Biosorption had a spontaneous and endothermic nature. In the treatment of a simulated effluent, the biosorbent removed 87.8% of the color, proving to be efficient. Therefore, the araticum seeds powder (ASP) can be used as a low-cost material for the treatment of colored effluents containing the crystal violet (CV) dye.

A high-efficient method for determining the total petroleum hydrocarbon (TPH) was established by gas chromatography-flame ionization detection, coupled with an efficient 10 m short chromatographic column; the analyzing period was narrowed to 5 mins. The limits of detection of the method included 1.47, 4.02, and 0.69 mg/kg, and the corresponding limits of quantification reached 4.45, 12.2, and 2.10 mg/kg for the three fractions C₁₀–C₁₆, C₁₇–C₃₄, and C₃₅–C₄₀, respectively. The method was employed to real samples to achieve the routine environmental monitoring of TPH in polluted sites from Fushan oilfield, China. As revealed from the analysis of 30 soil samples in the study area, a wide range of TPH concentrations were achieved: 61.6–7300 mg/kg (average, 1055 mg/kg) for ΣC₁₀–C₁₆, 438–14,280 mg/kg (average, 4544 mg/kg) for ΣC₁₇–C₃₄, 25.4–638 mg/kg (average, 250 mg/kg) for ΣC₃₅–C₄₀, and 617–15,348 (average, 5848 mg/kg) for ΣC₁₀–C₄₀, respectively. According to the Nemerow integrated pollution index, the Fushan oilfield has been slightly polluted by TPH. As suggested from the distribution of TPH concentrations, the main sources of TPH in soil samples of Fushan oilfield included oil spills during temporary storage, transportation, and oil exploitation. Adopting the developed method to delve into oilfield soil samples further verifies the effectiveness of the method, indicating that the method can well meet the growing demand of regulatory guidelines for related risk assessment and environmental monitoring and remediation strategy formulation.

Chlorination in a drinking water treatment plant is the critical process for controlling harmful pathogens. However, the reaction of chlorine with organic matter forms undesirable, harmful, and halogenated disinfection by-products. Carbonaceous disinfection by-products, such as trihalomethanes (THMs) and haloacetic acids (HAAs), are genotoxic or carcinogenic and are reported at high concentration in drinking water. This study is aimed at developing a mathematical model for predicting concentration levels of THMs and HAAs in drinking water treatment plants in South Korea because no previous attempts to do so have been reported for the country. The THMs concentration levels ranged from 29 to 39 μg/L, and those for the HAAs from 6 to 7 μg/L. Multiple regression models, i.e., both linear and nonlinear, for THMs and HAAs were developed to predict their concentration levels in water treatment plants using datasets (January 2015 to December 2016) from three treatment plants located in Seoul, South Korea. The constructed models incorporated principal factors and interactive and higher-order variables. The principal factor variables used were dissolved organic carbon, ultraviolet absorbance, residual chlorine, bromide, contact time, chlorine dose and temperature for treated water, and pH for both raw and treated water at the plant. The linear models for both THMs and HAAs were found to give acceptable fits with measured values from the water treatment plants and predictability values were found to be 0.915 and 0.772, respectively. The models developed were validated with a later dataset (January 2017 to July 2017) from the same water treatment plants. In addition, the models were applied to two different water treatment plants. Application and validation results of the constructed model showed no significant differences between predicted and observed values.

A new class of robust superhydrophobic cotton fabric was prepared by chemically grafting method for removing oil from contaminated waters. Furthermore, the mechanical, chemical, and thermal durability of superhydrophobic cotton fabric was evaluated in detail. The superhydrophobic cotton fabric did not only showed excellent separation efficiency (ca.100%) and ultrafast separation rate (ca. 13,600 L/h m²) but also exhibited excellent durability. Especially, the oil/water separation rate was almost 10 times than that reported in previous works. The work provides a new method to design and large-scale prepare oil/water separation materials with high performance for industrial use.

Sulfadiazine (SDZ) residues have been detected in manured soils as well as their adjacent water resources, but its behavior is still poorly understood in acidic tropical soils. This research aimed to evaluate sorption, leaching, and biodegradation of ¹⁴C-SDZ in four acidic soils from Brazil, using OECD guidelines. Except for the sand soil (Kd = 2.6 L kg⁻¹), SDZ sorption tended to be higher (Kd > 8.4 L kg⁻¹) and more hysteretic (ΔH >> 1) in acidic soils. When freshly applied, SDZ leaching was low (< 0.11% of applied radioactivity (AR)) and could not always be predicted by Kd values; but leaching was restricted when SDZ was aged for 62 days. SDZ mineralization was low (< 3%) but its dissipation was fast (DT₅₀ < 2.3 days and DT₉₀ < 6.3 days) due to fast initial degradation (an unknown metabolite was immediately formed, likely 4-hydroxysulfadiazine) and mainly to fast formation of non-extractable residues (NER) (> 78% of AR up to 7 days). For certain acidic soils, the abrupt breakdown of the SDZ suggests that degradation should be initially chemical and then followed by enzymatically driven reactions. The fast formation of NERs was attributed mostly to chemical bounding to soil humic substances (Type II-NER), but SDZ sequestration cannot be ruled out (Type I-NER). NERs represent a long-term environmental reservoir of SDZ that may cause deleterious effects on non-target organisms as well as promote antibiotic resistance to soil microbes.

Milk production has been estimated to contribute 3–4% of anthropogenic greenhouse gas (GHG) emissions. However, the carbon footprint associated with raw milk can vary, depending on a variety of factors, such as the geographical area, species of cow and production system. In this study, a global overview of research published on the carbon footprint (CF) of raw cow milk is provided. Additionally, two different dairy systems (semi-confinement and pasture-based) have been analysed by life-cycle assessment (LCA) in order to determine their effect on the CF of the milk produced. Inventory data were obtained directly from these facilities, and the main factors involved in milk production were included (co-products, livestock food, water, electricity, diesel, cleaning elements, transport, manure and slurry management, gas emissions to air etc.). In agreement with reviewed literature, it was found that the carbon footprint of milk was basically determined by the cattle feeding system and gas emissions from the cows. The values of milk CF found in the systems under study were within the range for cow milk production worldwide (0.9–4.7 kgCO₂eq kgFPCM⁻¹). Specifically, in the semi-confinement and the pasture-based dairy farms, 1.22 and 0.99 kgCO₂eq kgFPCM⁻¹ were obtained, respectively. The environmental benefits obtained with the pasture grazing system are not only mainly due to the lower use of purchased fodder but also to the allocation between milk and meat that was found to be a determining methodological factor in CF calculation. Finally, data from the evaluated dairy systems have been employed to analyse the influence of raw milk production on cheese manufacturing. With this aim, the CF of a small-scale cheese factory has also been obtained. The main subsystems involved (raw materials, water, electricity, energy, cleaning products, packaging materials, transport, wastes and gas emissions) were included in the inventory of the cheese factory. CF values were 16.6 and 14.7 kgCO₂eq kg⁻¹ of cheese for milk produced in semi-confinement and pasture-based systems, respectively. The production of raw milk represented more than 60% of CO₂eq emissions associated with cheese, so the primary production is the critical factor in reducing the GHG emissions due to cheese making.

The wastewater generated from fish processing industry contains a credible level of biodegradable proteins and low biodegradable fats, oils, and grease (FOG). The conventional biological treatment of fish processing wastewater (FPWW) containing high concentration of FOG faces the challenges of clogging, hindrance to sedimentation due to the formation of hydrophobic sludge along with lipids, flocculation of sludge with poor activity, dewatering of sludge due to the presence of lipids, and formation of aminated offensive odors. The present investigation employed baffled moving bed biofilm reactor (BMBBR), up-flow anaerobic sludge blanket (UASB) reactor, fluidized immobilized cell carbon oxidation (FICCO) reactor, and chemoautotrophic activated carbon oxidation (CAACO) reactors in series to treat FPWW. Five treatment options were evaluated to elevate the correct option for the treatment of FPWW. The treatment option V had established the removal efficiency of COD, 99 ± 0.1%; protein, 99 ± 0.2%; lipids, 100%; and oil and grease, 100%.

Copper and nonylphenol are two commonly found chemicals in the aquatic environment, particularly in the distribution area of the amphibian Rhinella arenarum. The current work evaluated the lethal toxicity of equitoxic and non-equitoxic binary mixtures of copper and nonylphenol on embryos and larvae of the South America toad by means of the standardized test, AMPHITOX. Joint toxicity of mixtures was assessed in several proportions of these compounds at different exposure times and was analyzed at different level of mortality effect (LC10, LC50 and LC90). Considering the LC50, the equitoxic mixture was always antagonistic independently of the exposure time and the developmental stage. Joint toxicity showed mainly an antagonistic pattern; nonetheless, some time-dependent additive interactions were observed. Regarding the LC10, synergistic interactions were found in embryos and larvae exposed to two different mixture proportions at several exposure times. This highlights the possible synergism of these chemicals at environmentally relevant concentrations. These results point out the relevance of assessing joint toxicity of environmental pollutants for environmental risk assessment.

To seek new mosquito control agents while avoiding the environmental impacts and toxicity hazards of conventional pesticides, the essential oil of Dysphania ambrosioides was obtained by hydrodistillation and analysed using GC–FID and GC–MS. The compounds 1-methyl-4-(1-methylethyl)-2,3-dioxabicyclo[2.2.2]oct-5-ene (cis-ascaridole), 1-methyl-4-(1-methylethyl) benzene (р-cymene), and 1-isopropyl-4-methyl-1,3-cyclohexadiene (p-mentha-1,3-diene also known as α-terpinene) were identified as the major components. The EO and the major fractions showed remarkable mosquitocidal activity against third instar larvae and adults of Culex quinquefasciatus Say. The oil and fractions were assayed at 3.125, 6.25, 12.5, 25, and 50 μl/l. Mortality was time- and dose-dependent. At 24 h post-exposure at an assayed concentration of 50 μl/l, the larval and adult mortalities ranged between 80.11–100% and 91.22–100%, respectively. Strong larvicidal and adulticidal activities were recorded in the cases of the crude oil and cis-ascaridole. The LC₅₀ values after 24 h of treatment ranged between 6.2–20.1 μl/l and 5.1–13.9 μl/l against larvae and adults, respectively. The corrected percentage mortalities increased over time with the tested plant oil and the major fractions relative to the control. The time required to achieve 50% mortality (LT₅₀) decreased remarkably with all treatments. The tested EO and major fractions effectively inhibited larval acetylcholinesterase activity with IC₅₀ values ranging from 8.44 to 64.80 mM compared with 2.08 × 10⁻³ mM for the reference standard, methomy. The results indicate the potential of developing natural mosquitocides against C. quinquefasciatus based on the tested EO and its major fractions. Graphical abstract

This study assessed the economic value of public urban green spaces (UGSs) in Kuala Lumpur (KL) city by using the hedonic price method (HPM). It involves 1269 house units from eight sub-districts in KL city. Based on the hedonic price method, this study formulates a global and local model. The global model and local model are analyzed using ordinary least square (OLS) regression and geographically weighted regression (GWR). By using the hedonic price method, the house price serves as a proxy for public urban green spaces’ economic value. The house price is regressed against the set of three variables which are structural characteristics, neighborhood attributes, and environmental attributes. Measurements of interest in this study are environmental characteristics, including distance to public UGSs and size of public UGSs. The results of the OLS regression illustrated that Taman Rimba Kiara and Taman Tasik Titiwangsa provide the maximum economic value. On average, reducing the distance of the house location to Taman Rimba Kiara by 10 m increased the house price by RM1700. Similarly, increasing the size of the Taman Tasik Titiwangsa by 1000 m² increases the house price by RM60,000. The advantage of the GWR result is the economic value of public UGSs which can be analyzed by the specific location according to sub-district. From this study, the GWR result exposed that the economic values of Taman Rimba Bukit Kiara and Taman Tasik Titiwangsa were not significant in each of the sub-district within KL city. Taman Rimba Bukit Kiara was negatively significant at all sub-districts except Setapak and certain house locations located at the sub-district of KL. In contrast, Taman Tasik Titiwangsa was positively significant at all sub-districts except certain house locations at the sub-districts of Batu, KL, Setapak, and KL city center. In conclusion, results show that the house price is influenced by the environmental attribute. However, even though both of these public UGSs generate the highest economic value based on distance and size, its significant values with an expected sign are only obtained based on the specific house location as verified by the local model. In terms of model comparison, the local model was better compared with the global model.