Industrial River Water Research Articles

Synthesis of hexagonal zinc oxide and rod-shaped zinc stannate as an efficient electrocatalyst for electrochemical detection of calcium channel antagonist

The present study describes the electrochemical sensing of nifedipine (NFDP) with the fabrication of a Zn2SnO4/GC electrode. NFDP, a calcium channel blocker used to treat several diseases is taken into concern due to its high-risk factor. The zinc stannate (Zn2SnO4) with excellent unique properties was modified over the working electrode surface. The Zn2SnO4 was further taken for the physical and morphological characteristic analysis. The XRD, XPS, and FTIR results resembled the well-defined formation of Zn2SnO4. While the rod-like structure of Zn2SnO4 were observed with FESEM analysis. The electrochemical detection of NFDP was studied initially with different parameters being varied in order to obtain a constant response. The limit of detection was about 0.0088 μM with a linear range of 0.24–250.47 µM with a sensitivity 4.86 μA μM−1 cm2. The repeatability and reproducibility analysis showed excellent responses even for continuous monitoring at several intervals. The selectivity study had a good selective response towards NFDP in the presence of various interferant analytes. The real sample detection performed in industrial river water, human blood serum, and urine samples showed optimum recovery results. Thus, the investigation of Zn2SnO4 electrocatalyst for NFDP detection will be a reliable approach for monitoring the effects of NFDP in the living ecosystem.

Spatial Distribution Characteristics and Source Appointment of Heavy Metals in Soil in the Areas Affected by Non-Ferrous Metal Slag Field in the Dry-Hot Valley

In this study, the contents and associated soil properties of 6 metal elements (Pb, As, Cu, Zn, Ni, Cr) were measured in 63 topsoil samples in the affected areas of a typical non-ferrous metal slag field in Huili City, Sichuan Province, China. The associated soil properties of the 6 metals include Ammonium Nitrogen (NH4+-N), Nitrate (NO3−-N), Available Phosphorus (AP), Available Potassium (AK), Electrical Conductivity (EC), Cation Exchange Capacity (CEC), Soil Water Content (SWC), and pH. Multivariate statistics-spatial analysis-soil pollution comprehensive evaluation method was used to quantify the environmental pollution degree of heavy metals in the topsoil and divided (zone) the slag field based on the degree of pollution. Pearson correlation analysis and positive matrix factorization (PMF) were used to identify and quantitatively analyze pollution sources and their contributions. The results show that the average contents of Pb, As, Cu, Zn, Ni, and Cr were 13.27, 19.87, 6.91, 50.55, 25.06, and 77.71 mg·kg−1, respectively. Nemerow comprehensive evaluation results showed that the sites with Slight Pollution and Mild Pollution accounted for 26.98% and 3.17% of the total sampling sites, respectively. Approximately 70% of the sampling sites in the study area had no heavy metal pollution in the soil. Sites with No Pollution or Slight Pollution were mainly distributed in the forest areas with vegetation coverage, while sites with Moderate Pollution or Heavy Pollution were mainly distributed in crop planting areas and areas near slag fields. PMF model revealed four pollution sources: natural sources, mixed industrial and transportation sources, agricultural sources, and industrial river water. These results will provide theoretical references for the utilization and treatment of heavy metal-contaminated soil around the slag field in the dry-hot valley.

Influence of temperature variation on spinel-structure MgFe2O4 anchored on reduced graphene oxide for electrochemical detection of 4-cyanophenol.

Theeffect of annealing temperature variance on magnesium ferrites (MgFe2O4) later anchored on reduced graphene oxide (rGO) forming hybrid nanocomposite is demonstratedand its electrochemical performance investigatedby using ascreen-printed carbon paste electrode (SPCE) for detection of theenvironmental hazardous phenolic compound 4-cyanophenol (4-CY). The MgFe2O4 (MFO-600°C) displayed an enhanced charge transfer ratio with high conductivity and electrocatalytic activity. To confirm the structural and morphological parameters of the rGO-MFO-2 hybrid micro/nanocomposite, X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron microscopy (XPS), and field-emission electron microscopy (FE-EM) with EDX mapping have beenutilized. The rGO/MFO-2/SPCE electrode displayed high catalytic performance in detecting 4-CY with good sensitivity of 6.836μAμM-1cm-2 in a working range0.001 to 700μM with a limit of detection of0.0012μM by using differential pulse voltammetry (DPV). This is achieved for the active interaction between rGO and MFO-2 active surface site areas resulting in good electrochemical activity and high electron transfer rate. Moreover, 4-CY detection has been performed in the presence ofvarious interferents and through real-time analysis in samples like tap water, industrial river water, and fish which resulted in admirable recovery.Graphical abstract.

Assessment of microbiological and physicochemical parameters of ground water: A case study of Gikondo industrial park, Kigali, Rwanda

The main objective of our study was to determine the physicochemical and microbiological characteristics of two water samples: river and ground water, in Gikondo industrial park, compared to the tap water. Samples were collected from the main three sources: industrial park effluent water (river water), industrial spring water and tap water. The physicochemical properties were assessed and recorded as pH (6.9-7.75, 6.00-6.20 and 6.01-6.3 for river, spring and tap water respectively), turbidity (42-92.0, 8.9-9.1 and 12.3-14.1 for river, spring and tap water respectively), chloride (Cl-) (7.1-10.5, 9.5-12.5 and 1.8-2.8 for river, spring and tap water respectively), thiocyanide (SCN-) (++++; +++; +), chemical oxygen demand (COD) (5.0-8.9, 7.4-9.6 and 11.5-13.9 for river, spring and tap water respectively), biological oxygen demand (BOD) (0.60-0.75, 1.20-1.67 and 21.24-24.73 for river, spring and tap water respectively) and dissolved oxygen DO(0.90-0.98, 1.9-2.3 and 32-34 for river, spring and tap water respectively). Microbial analysis was conducted based on different indicators such as gas formation by catalase activity, MR/VP test and Indole formation test. In all, the microbial analysis resulted in the presence of Klebsiella, Enterobacter, Staphylococcus and Escherichia coli in the industrial river water (river water), which showed a maximum pollution rate compared to the other two samples. Such results will definitely have a key role to ascertain the impact of the industrial effluent on Gikondo industrial Park area and any potential harmful and hazardous effects on aquatic organisms, humans and plants within that environment.Key Words: Industrial effluent, Gikondo industrial park, physicochemical properties, microbiologicalanalysis, water analysis.