Current available treatment technologies for saline wastewater and land-based treatment as an emerging environment-friendly technology: A review

Physicochemical assessment of industrial effluents of Kala Sanghian drain, Punjab, India

The discharge of industrial effluents has a significant impact on the Water Quality Index (WQI) of the water bodies and is a major source of contamination of groundwater. The present study investigated the physicochemical characteristics and scrutinized the pollution potential of the tannery, textile, and electroplating effluents uploading into the Kala Sanghian drain, located in Jalandhar, Punjab, India. In this study, 12 samples were collected from the four sites (leather complex drain (LD), leather complex outlet (LO), focal point drain (FD), and Bulandpur drain (BD)) of Kala Sanghian drain in the dry season. The result showed that the drain under consideration is very much contaminated and the water is not suitable for irrigation and agricultural purposes. Rather it has a bad impact on the health of local people, the physiology of aquatic organisms, and the soil quality of agricultural land nearby. The present study confirmed the water quality index was more than 100, indicating a highly contaminated drain and water is unfit for any use. The correlation analysis shows that there exists a positive correlation between TDS and temperature (r = 0.994), DO and pH (r = 0.808), BOD and temperature (r = 0.987), BOD and TDS (r = 0.978), EC and temperature (r = 0.963), EC and TDS (r = 0.954), and EC and BOD (r = 0.956). The principal component analysis (PCA) confirms that PC1 alone has more than 89% of the variance with high positive loading for TDS, temperature, EC, and BOD. The hierarchical cluster analysis (HCA) reflected two clusters where cluster 1 consists of pH, DO, temperature, and BOD of water while cluster 2 consists of TDS and EC of water. The PCA and HCA study of the data set confirms the high degree contribution of anthropogenic activities through the application of chemicals in agriculture, disposal of municipal waste, and industrial effluents in the deterioration of water quality. The results of the study will help to enhance the sustainable action plan for the management of industrial effluents in the studied area.

Growth performance of different forestry species irrigated with moderately saline wastewater

A seven month, pot study was conducted to evaluate the impact of moderately saline wastewater on the growth potential of six forestry plant species viz., Eucalyptus calmaldulensis, Dendrocalamus strictus, Casurina equisetfolia, Cassia fistula, Melia dubia, and Bambusa arundinacea under different drainage conditions namely, well-drained saline (WDS) condition and poor-drained saline condition (PDS) and the control with well-drained non-saline condition. WDS treatment resulted in no mortality whereas PDS treatment resulted in mortality in the range of 33-66%. The plant height and root dry biomass increased in the range of 145% to 221.6% and 4.3-37.1 g respectively in WDS treatment, however, 23.60% to 173.4% and 4.1-10.1 g in PDS treatment. Among all, Eucalyptus camaldulensis and Dendrocalamus strictus showed high Na+ accumulation in roots (2.16 ± 0.02% and 1.13 ± 0.01%), shoots (1.98 ± 0.01% and 0.74 ± 0.01%) and leaves (1.27 ± 0.02% and 0.86 ± 0.01%) in WDS treatment and in case of PDS treatment root (1.01 ± 0.01% and 0.23 ± 0.01%), shoot (1.12 ± 0.02% and 0.11 ± 0.01%), and leaf (0.07 ± 0.01% and 0.1 ± 0.02). The overall performance of both Eucalyptus camaldulensis and Dendrocalamus strictus was highest in WDS treatment. Therefore, it was concluded, that both plants had better performance than other plant species, a proper drainage system defines the overall productivity and treatment efficiency.

Biomass hydrogels combined with carbon nanotubes for water purification via efficient and continuous solar-driven steam generation

Solar vapor generation is a promising, environmentally friendly solution for water purification. The development and design of new materials and supporting devices for efficient energy conversion and clean water production are essential for the practical application of solar-driven desalination and water purification. In this study, an environmentally friendly and economical biomass hydrogel-based solar evaporator with a controllable shape was developed in a simple method by integrating carbon nanotubes (CNTs) into a sodium alginate (SA) hydrogel network. The evaporator had a high solar absorption rate (94.3%) and satisfactory hydrophilicity and could effectively avoid salt crystallization during the desalination process. This study took advantage of the aforementioned merits, and a high evaporation rate of 1.699 kg m^-2 h^-1 and a conversion efficiency of 86% were achieved under 1.0 sun irradiation. The evaporator could efficiently remove Na⁺, K⁺, Ca²⁺, and Mg²⁺ from seawater with a removal rate of up to 99.3% and a good decolorization effect on methylene blue (MB) and methyl orange (MO) dye wastewater, whose colour could be completely removed. This study provides a simple, practical, and economical method to prepare hydrogel-based evaporators that utilize abundant solar energy for large-scale desalination and wastewater treatment.

Use of enzymatic biomarkers of Labeo rohita to study the effect of polybrominated diphenyl ether (BDE- 209) via dietary exposure in laboratory conditions

Fishes have been widely used as a representative to estimate the health of an aquatic ecosystem. In the present study, Labeo rohita was selected for biomarker study against decabromodiphenyl ether (BDE-209), a persistent organic pollutant (POP), as it is a widely used Indian carp. The results suggested significant effects on the optimum metabolism of Labeo rohita. After 48 to 72 h of exposure, most of the biomarkers such as lactate dehydrogenase (LDH), creatine kinase (CK), serum glutamic pyruvic transaminase (SGPT), serum glutamic oxaloacetic transaminase (SGOT), and hepatosomatic index (HSI) increased drastically indicating the higher index of tissue and liver damage. On the contrary, succinic dehydrogenase (SDH), acetylcholinesterase (AChE), and alkaline phosphatase (ALP) showed a reverse trend suggesting the shifting of fish metabolism towards anaerobic respiration mode because of induced stress. Increased catalase (CAT) activity was also observed, which indicated increased abundance of reactive hydroxyl species and therefore a possible oxidative stress in fishes. It is further suggested to understand and examine the biotransformation characteristics and degradation pathways of polybrominated diphenyl ether (PBDE)s, which would be useful to comprehend their environmental fate.

Hypersaline Wastewater Produced from Pickled Mustard Tuber (Chinese Zhacai): Current Treatment Status and Prospects

Pickled mustard tuber, a worldwide condiment, is increasing at a fast growth rate. Its production generates a considerable amount of hypersaline wastewater containing NaCl of 7 wt.%, COD of 30,000 mg L−1, NH3-N of 400 mg L−1, and TP of 300 mg L−1. Pickled mustard tuber wastewater (PMTW) has severe effects on crops, deterioration of water quality, soil infertility and ecological systems. Due to the technic difficulties and insufficient support from the local governments; however, PMTW has not yet been widely investigated and well summarized. Therefore, this manuscript reviewed the relatively latest advances in PMTW. Physicochemical and biological hybrid processes mainly treat PMTW and the corresponding cost is 6.00 US dollars per ton. In the context of double carbon capture capacity in China and the development of the pickled mustard industry, PMTW sauce and sustainable reuse such as nutrient recovery, acid and alkaline regeneration and renewable energy may be bright prospects.

A Modified Lysimeter Study for Phyto-Treatment of Moderately Saline Wastewater Using Plant-Derived Filter Bedding Materials

The present study focuses on determining the phyto-treatment efficiency for treatment of moderately saline wastewater using organic raw materials, such as rice husk, coconut husk, rice straw, and charcoal. The moderately saline wastewater with total dissolved solids (TDS) concentration up to 6143.33 ± 5.77 mg/L was applied to the lysimeters at the rate of 200 m3 ha-1 day-1 in five different lysimeter treatments planted with Eucalyptus camaldulensis (T1, T2, T3, T4, and T5). T1 was a control without any filter bedding material, whereas rice straw, rice husk, coconut husk, and charcoal were used as filter bedding materials in the T2, T3, T4, and T5 treatment systems, respectively. Each treatment showed significant treatment efficiency wherein T3 had the highest removal efficiency of 76.21% followed by T4 (67.57%), T5 (65.18%), T2 (46.46%), and T1 (45.5%). T3 and T4 also showed higher salt accumulation, such as sodium (Na) and potassium (K). Further, the pollution load in terms of TDS and chemical and biological oxygen demand significantly reduced from leachate in the T3 and T4 treatments in comparison with other treatments. Parameters of the soil, such as electrical conductivity, exchangeable sodium percentage, and cation exchange capacity did not show values corresponding to high salinity or sodic soils, and therefore, no adverse impact on soil was observed in the present study. Also, Eucalyptus camaldulensis plant species showed good response to wastewater treatment in terms of growth parameters, such as root/shoot weight and nitrogen, phosphorus, and potassium (NPK) uptake, plant height, biomass, and chlorophyll content. Root and shoot dry weight were in the order T3 (51.2 and 44.6 g)>T4 (49.3 and 43.5 g) > T5 (47.6 and 40.5 g) > T2 (46.9 and 38.2 g) > T1 (45.6 and 37.1 g). Likewise, the total chlorophyll content was highest in T3 (12.6 μg/g) followed by T4 (12.3 μg/g), T5 (11.9 μg/g), T2 (11.5 μg/g), and the control, that is, T1 (11.0 μg/g). However, the most promising results were obtained for T3 and T4 treatments in comparison with the control (T1), which implies that, among all organic raw materials, coconut and rice husks showed the highest potential for salt accumulation and thereby wastewater treatment. Conclusively, the findings of the study suggest that organic raw material-based amendments are useful in managing the high salts levels in both plants and leachates.