Trend analysis and change point detection in a time series are frequent analysis tools. Change point detection is the identification of abrupt variation in the process behavior due to distributional or structural changes, whereas trend can be defined as estimation of gradual departure from past norms. We examine four different change point detection methods which, by virtue of current literature, appear to be the most widely used and the newest algorithms. They are Wild Binary Segmentation, E-Agglomerative algorithm for change point, Iterative Robust Detection method and Bayesian Analysis of Change Points. We measure the power and accuracy of these current methods using simulated data. We draw comparisons on the functionality and usefulness of each method. We also analyze the data in the presence of trend, using Mann–Kendall and Cox–Stuart methods together with the change point algorithms, in order to evaluate whether presence of trend affects change point or vice versa.

The extensive use of nanoparticles under different industrial processes and their release into the environment are of major concerns in the present global scenario. In the present study, the effects of activated carbon-based TiO₂ (AC-TiO₂) nano-composite on the seed germination of Solanum lycopersicum (tomato) and Vigna radiata (mungbean) were investigated. The size of nanoparticles used in the study ranged from 30 to 50 nm, and their concentrations were from 0 to 500 mg L⁻¹. The composites were synthesized by sol–gel method and further characterized by scanning electron microscopy, Energy-dispersive X-rays spectroscopy (EDX), Raman spectroscopy, Fourier transform infrared spectroscopy and X-ray diffraction to investigate all the surface structural and chemical properties of AC-TiO₂ nano-composite. The results showed that increase in nano-composite concentration improves the germination rate and reduces germination time up to a certain concentration. Therefore, employing AC-TiO₂ nano-composites in suitable concentration may promote the seed germination and also reduce the germination time in Solanum lycopersicum and Vigna radiata. Further, it may help to understand the interface of TiO₂ nanoparticles with the environment and agriculture before its application to the field.

The study investigated the responses of Amaranthus hybridus to effluent from an aluminum plating plant in Lagos, Nigeria. Seedlings were raised from seeds and were grouped into three categories, each representing a treatment. The first group which is the control received 250 ml of water via the roots every 3 days, the second category received half-strength effluent via the roots every 3 days, while the third group received full-strength effluent via the roots every 3 days throughout the study period. Physiological and biochemical, as well as metabolic, parameters representative of oxidative damage and antioxidant activity were evaluated after the treatments. The physicochemical analysis of the effluent showed that total suspended solids, Al and Zn levels were higher than the recommended standards. The biomass and the protein content of the control were 18.01 g and 0.835 mg/g dry wt, respectively, as against 12.04 g and 0.368 mg/g dry wt observed in the treated plants. In contrast, effluent treatment caused a significant increase in malondialdehyde level as well as activities of antioxidant enzymes. The present study revealed that the effluent adversely affected growth and development of A. hybridus. Continual discharge of these industrial effluents could have a negative impact on the environment especially to fragile ecosystems.

Perchlorate and chlorate are inevitable components in rocket propellants, fireworks, water treatment, bleaching, textile industry, etc. Knowingly or unknowingly, wide use of these chemicals contaminates drinking water systems. The present study assessed the perchlorate and chlorate contamination of bottled water and other drinking well, tap, bore well, rainwater sources of Kerala and other parts of Peninsular India. Other drinking water samples were collected during the pre-monsoon, monsoon and post-monsoon from the 14 districts of Kerala and were analyzed for perchlorate and chlorate using liquid chromatography–mass spectrometry. Most of the locally available brands of bottled water were found to be contaminated with perchlorate and chlorate. Mean value of perchlorate was found to be 93.19 ppb, and that of chlorate was 3692.07 ppb, both exceeding the health reference level. The continuous consumption of water with high level of perchlorate content can cause high risk, and the probability of increasing thyroid disorders is high. Perchlorate was detected from well, tap and bore well water samples, and the maximum perchlorate was observed for the pre-monsoon season, whereas the minimum noticed in the monsoon samples. The high concentration of perchlorate detected in groundwater was mainly due to the industrial units and firework manufacturing and display sites.

The fate and transport of Escherichia coli (E. coli) in lotic waters through vegetated filter strips (VFSs) was evaluated in a field model pasture, utilizing VFSMOD Windows along with direct pathogen testing. This study assessed effects of VFS on transport and deposition rates of E. coli in lotic overland flow waters. The VFS measured 44 m long by 40 m wide, covering an area of 1584 m² and land slope of 15 %. Cowpat was applied onto the model pasture and washed by overland flow into the VFS. The 4-methylumbelliferyl β-d-glucuronide substrate confirmed the identity of E. coli prior to cowpat application and after isolating them from soil using centrifugation and membrane filtration techniques. Napier grass root system recorded the highest recovery rates of E. coli at 99.9 % along the length of VFS III. This efficiency reduced significantly (p < 0.05; df = 29) to 95 % in Kikuyu grass and 75 % in Couch grass–Buffer grass. The data demonstrated similarity in transport of manure-borne E. coli and organic carbon (OC) through all the simulated VFS. These results indicated that OC could be used as a true natural tracer of manure-borne E. coli, a pollution indicator organism of lentic and lotic surface waters provided the OC release kinetics from cowpat were similar to that of E. coli kinetics. Thus, efficient filtering to reduce E. coli concentrations and load in overland flows requires managing combined grass species, agro-pastoral systems models and dispersed or preferential flows to enhance surface water quality standards.