Inferring causality has long been a challenging task in environmental impact studies and monitoring programs, mostly because of the problem of confounding bias, i.e. the difficulty of separating impact from natural variation. Traditional approaches for dealing with confounding, despite improvements in study design and statistical analysis, are inadequate. Using aquatic biota as a case study, this review explains the limitations of traditional methods used to separate the impact of human-made pollution from natural variation in the environment. Advantages and disadvantages of the traditional and novel techniques are enumerated. Bayesian networks (BNs) and structural equation modelling (SEM) as causal modelling techniques are introduced as approaches to improve environmental impact monitoring.

A previously isolated indigenous strain of Pseudomonas sp. was used to treat effluents, a synthetic and an industrial-containing benzalkonium chloride (BAC), in continuous upflow biofilm aerobic reactors. The reactor used to treat the synthetic effluent was constructed from Plexiglas® and filled with hollow polyvinyl chloride (PVC) cylinders as support material, whereas the one used to treat the industrial effluent was constructed from PVC and had a high recirculation flow rate and lightweight expanded clay aggregate (LECA®) as support material. Biodegradation was evaluated by spectrophotometry, HPLC, and microbial growth. Detoxification was evaluated by using Vibrio fisheri, Pseudokirchneriella subcapitata, and Lactuca sativa as test organisms. Maximal BAC influent concentrations were of 383.4 and 1172.0 mg L⁻¹ respectively, which corresponds to a maximal organic load of 49.8 and 146.5 g BAC m⁻³ day⁻¹. The efficiency of the reactors was higher than 99.3% in terms of compound removal and 97.0% in terms of COD removal. Complete detoxification of the effluent was demonstrated for the synthetic effluent, whereas a toxicity removal higher than 97% was reached in the case of the industrial effluent. The promising behavior of the isolated indigenous strain to degrade BAC in continuous reactors allows us to suggest its possible use in remediation processes.

Chemical treatment could improve the adsorption performance of biochars (BC). In order to deal with Pb(II) pollution, four types of biochars including unmodified, acid-treated, alkali-treated, and magnetic-treated pig manure-derived biochars (PBCs) were prepared. The effect of chemical treatment on the physical property, chemical composition, and the adsorption behavior of biochars was compared. Magnetic and alkali treatment improved pore volume and specific surface areas, and the adsorption capacity and rates were enhanced. In contrast, the adsorption capacity of acid-treated BC decreased due to the significant decrease of ash content. The magnetic samples displayed the satisfactory absorption performance, which could achieve 99.8% removal efficiency within 15 min at a Pb(II) concentration of 50 mg/L. Considering its properties of excellent adsorption performance, fast reaction rate, and convenient recovery by an external magnetic field, magnetic biochar based on pig manure may provide an effective way to remove heavy metals and decrease the pig manure solid waste.

The issues of heavy metal contamination in water sources have been increasing substantially along with the rapid pace of industrial revolution. Lead, particularly, is one of the heavy metals that received considerable attention lately due to its frequent detection in the environment and hazardous effects. Although conventional water treatment processes had been utilized for ages, it is still a challenge to remove lead in the treatment plant effectively. In line with the advancement of chemistry and nanotechnology, the study on hydroxyapatite (HAp) nanopowder made from fish waste (skin, bones, and scales) has brought to its beneficial use as an adsorbent for lead removal in water. This paper reviews on the sources, occurrences, and health effects of lead as well as the treatment of lead using HAp adsorbent for its removal in water.

Crude water extract of the ground longan seeds which have been disposed in a large amount annually in Northern Thailand has been used in a simple and rapid microwave synthesis of ZnO nanoparticles. The particles were characterized by the UV-vis spectroscopy, Fourier-transformed infrared spectroscopy, X-ray diffraction, electron diffraction, energy dispersive X-ray spectroscopy, and transmission electron microscopy and revealed to be pure hexagonal phase. Influences of zinc precursor in the extract, microwave power, and irradiation time on particle sizes were studied. The use of 800 W and 30 cycles of the microwave irradiation provided the ZnO particles of 10–100 nm in size with an active surface area, a band gap energy, and a zero-point charge of 35 m²·g⁻¹, 3.42 eV, and pH 7.7, respectively, after the calcination. Photocatalytic efficiencies of the synthesized particles were evaluated through the decolorization of methylene blue, malachite green, methyl orange, and orange II, and proved to be on par with commercially available titanium dioxide (Arroxide®P-25) under the same conditions. The use of the longan seeds biowaste as a sustainable supply of natural reagents for the green synthesis of ZnO nanoparticles which can be employed further for waste water treatment of the local textile dyeing industry is therefore presented. Graphical Abstract

The application of conventional physicochemical and microbiological techniques for the removal of organic pollutants has limitations for its utilization on wastewaters as landfill leachates because of their high concentration of not easily biodegradable organic compounds. The use of ozone-based technologies is an alternative and complementary treatment for this type of wastewaters. This paper reports the study of the degradation of landfill leachates from different stages of a treatment plant using ozone and ozone + UV. The experimental work included the determination of the temporal evolution of COD, TOC, UV254, and color. Along the experimental runs, the instantaneous off-gas ozone concentration was measured. The reaction kinetics follows a global second order expression with respect to COD and ozone concentrations. A kinetic model which takes into account the gas liquid mass transfer coupled with the chemical reaction was developed, and the corresponding parameters of the reacting system were determined. The mathematical model is able to appropriately simulate COD and ozone concentrations but exhibiting limitations when varying the leachate type. The potential application of ozone was verified, although the estimated efficiencies for COD removal and ozone consumption as well as the effect of UV radiation show variations on their trends. In this sense, it is interesting to note that the relative ozone yield has significant oscillations as the reaction proceeds. Finally, the set of experimental results demonstrates the crucial importance of the selection of process conditions to improve ozone efficiencies. This approach should consider variations in the ozone supply in order to minimize losses as well as the design of exhaustion methods as multiple stage reactors using chemical engineering design tools.

In an attempt to mitigate the effects of extreme natural events caused by greenhouse gases (GHGs), a significant number of researchers and environmentalists have repeatedly stressed the importance of implementing protective measures, including the promotion of green consumption. This study examined the elements that motivated the willingness and the practice of green behavior (GB) among low-income households in coastal Peninsular Malaysia. To meet the research objectives, this study adopted the survey questionnaire method to collect data from 380 low-income households. The findings revealed that self-efficacy (SE) and environmental concerns (EC) have statistically significant effects on the attitude toward green products (ATT), while subjective norms (SN) and perceived behavioral control (PBC) have influence on the intention of green vehicles. Eventually, the study discovered the effects of the intention to adopt green vehicle on green vehicle adoption behavior. Hence, the findings of this study provide new insights for policymakers in Malaysia to place more emphasis on improving consumer attitudes, social standards, and PBC, which will ultimately contribute to the adoption of environment-friendly vehicles. In addition, car manufacturers should support this program by designing products and options that would encourage those in the low-income group to replace their conventional vehicles with green alternatives in Malaysia.

Vibrio cholerae is a leading waterborne pathogen worldwide. Continuous monitoring of V. cholerae contamination in aquatic products and identification of risk factors are crucial for assuring food safety. In this study, we determined the virulence, antimicrobial susceptibility, heavy metal tolerance, and genetic diversity of 400 V. cholerae isolates recovered from commonly consumed freshwater fish (Aristichthys nobilis, Carassius auratus, Ctenopharyngodon idellus, and Parabramis pekinensis) collected in July and August of 2017 in Shanghai, China. V. cholerae has not been previously detected in the half of these fish species. The results revealed an extremely low occurrence of pathogenic V. cholerae carrying the major virulence genes ctxAB (0.0%), tcpA (0.0%), ace (0.0%), and zot (0.0%). However, high incidence of virulence-associated genes was observed, including the RTX toxin gene cluster (rtxA-D) (83.0–97.0%), hlyA (87.8%), hapA (95.0%), and tlh (76.0%). Meanwhile, high percentages of resistance to antimicrobial agents streptomycin (65.3%), ampicillin (44.5%), and rifampicin (24.0%) were observed. Approximately 30.5% of the isolates displayed multidrug resistant (MDR) phenotypes with 42 resistance profiles, which were significantly different among the four fish species (MARI, P = 0.001). Additionally, tolerance of isolates to heavy metals Hg²⁺ (49.3%), Zn²⁺ (30.3%), and Pb²⁺ (12.0%) was observed. The enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR)-based fingerprinting of the 400 V. cholerae isolates revealed 328 ERIC-genotypes, which demonstrated a large degree of genomic variation among the isolates. Overall, the results of this study support the need for food safety risk assessment of aquatic products.

The environmental behavior of paclobutrazol in soil and its toxicity were studied by field investigation and an outdoor pot experiment, and the residue of paclobutrazol was detected by gas chromatography–mass spectrometry. Field investigation has found that the residual paclobutrazol in the former succession crop could severely inhibit the growth of succeeding crops of potato; with migration and transformation of residual paclobutrazol in the soil, the stems of potato were thickened with residual amount of 1.23 mg kg⁻¹, the growth was slow, and the height of potato in soil with residual amount of 1.34 mg kg⁻¹ and the control was significantly different. The degradation dynamics of paclobutrazol fits with the first-order degradation kinetics, although T₁/₂ of paclobutrazol of the taro planting soil was 30.14–46.21 days and the residual paclobutrazol remained detectable even on day 120 after application. Taro leaves were sensitive to the stress of paclobutrazol pollution; the taro leaf thickness increased, the leaf area decreased, the chlorophyll content per area unit of taro leaf showed an obvious increased trend, and SOD and CAT activities and MDA and proline content increased significantly. Paclobutrazol promoted the tillering of taro, and the taro seedlings were dwarfed by 58.01, 63.27, and 75.88% at different concentrations. It indicated that taro had strong stress response ability under paclobutrazol pollution.

One of the innovations introduced toward tackling the heightening of environmental impact is green technology. In the agricultural industry, the implementation of green fertilizer technology (GFT) for the modern development of environmentally friendly technology is a necessity. Within the Malaysian agriculture sector, the GFT application is needed to increase production levels among all crops. One of the essential commodities of all crops has always been paddy, given its status as the staple food among the country’s population. Paddy production with the adoption of GFT potentially opens the path toward sustainable development in the industry as well as it also provides the food safety aspect. Moreover, this helps farmers to improve their productivity on paddy production in Malaysia. This paper attempts to evaluate the contributing socio-psychological factors, innovation attributes of environmental factors, and channels of communication to decision-making among farmers in Malaysia on GFT. Furthermore, this research also aims to assess the moderating role of cost between the farmer’s behavioral intention and the adoption of GFT. The sampling process followed the stratified sampling technique—overall, 600 survey questionnaires were dispersed and 437 effective responses were received. The structural analysis results obtained have revealed significant positive effect for perceived awareness, attitude, group norm, perceived behavioral control, environmental concern, agro-environmental regulations, relative advantage, compatibility, trialability, and observability, and on farmer’s behavioral intention, a significant effect for paddy farmer’s behavioral intention in order to adopt of GFT. Further, the interaction effects of cost on the link between farmer’s behavioral intention and adoption of GFT are statistically significant. Though, the finding could not back an outcome for the subjective norm, complexity, and mass media on farmer’s behavioral intention. Finally, critical outcomes obtained in this research contribute to deepening the thoughtfulness of paddy farmers’ adoption of GFT. This study concludes with policy recommendations and future directions of the research.