Desalination and Detoxification of Textile Wastewater by Novel Photocatalytic Electrolysis Membrane Reactor for Ecosafe Hydroponic Farming

In this study, a novel photoelectrocatalytic membrane (PECM) reactor was tested as an option for the desalination, disinfection, and detoxification of biologically treated textile wastewater (BTTWW), with the aim to reuse it in hydroponic farming. The anionic ion exchange (IEX) process was used before PECM treatment to remove toxic residual dyes. The toxicity evaluation for every effluent was carried out using the Vibrio fischeri, Microtox® test protocol. The disinfection effect of the PECM reactor was studied against E. coli. After PECM treatment, the 78.7% toxicity level of the BTTWW was reduced to 14.6%. However, photocatalytic desalination during treatment was found to be slow (2.5 mg L−1 min−1 at 1 V potential). The reactor demonstrated approximately 52% COD and 63% TOC removal efficiency. The effects of wastewater reuse on hydroponic production were comparatively investigated by following the growth of the lettuce plant. A detrimental effect was observed on the lettuce plant by the reuse of BTTWW, while no negative impact was reported using the PECM treated textile wastewater. In addition, all macro/micronutrient elements in the PECM treated textile wastewater were recovered by hydroponic farming, and the PECM treatment may be an eco-safe wastewater reuse method for crop irrigation.

Evaluation of compost quality from municipal solid waste integrated with organic additive in Mizan–Aman town, Southwest Ethiopia

Background The present study evaluated the compost quality from municipal solid waste (MSW) and organic additives of coffee by-products and leaf of Millettia ferruginea. Compost sample (n = 30) was taken from fresh compost materials and MSW and different organic additive treatments (T1, T2, T3, T4, and T5). Compost treatments phytotoxicity test was conducted using lettuce seed (Lactuca Sativa L. var. crispa). Analysis of variance (ANOVA) was performed using SPSS (version 22) on major compost quality characteristics. Results The compost Physico-chemical characteristics like temperature (26.4 °C), moisture content (45.5%), electrical conductivity (4.6 mS/cm), pH (7.9), total nitrogen (1.2%) and phosphorous content (2918 ppm) in T4 and T5 were analogous but both are significantly different from T3, T2 and T1 compost treatments. Phytotoxicity test using 100% compost treatment media showed that T4 (101%) and T5 (102%) are phytonutrient for lettuce plant. While, T3 and T2; and T1 compost treatments are non-phytotoxic and moderately phytotoxic respectively to lettuce plant. Conclusion Therefore, compost from MSW + M. ferruginea (T4) and MSW + coffee pulp + M. ferruginea (T5) are important for improving the physico-chemical characteristics of compost and are phytonutrient for lettuce plant. Thus, for effectively management of the 75% of organic fraction of waste generated from households in the study area, recycling methods like composting with organic additives must be used at large.

Rice Husk Ash Incorporation in Container Substrates Effect on Romaine Lettuce Plant Growth

Primary substrate components include peat moss, vermiculite, perlite, bark, and compost are commonly-used substrate in horticultural crop production.These substrate components are high cost due to the extreme cost of transportation, fuel for extraction, and processing. Local rice husk ash (RHA) as an alternative substrate component was used to evaluatethe growth of Romaine Lettuce plants in response to the application of different incorporations of RHA in container substrates. The test was conducted with a completely randomized design of four RHA treatment, rates at 0%, 10%, 30%, and 50% (by vol.), with 10 replicates. The results showed that plant stem elongation increased with decreased incorporations of RHA application. Although the fresh weight of plants(shoot or root)and number of leaves increased with the RHA application, no significant difference for the plant biomass produced (dry weight of root and shoot) betweenthe 30% and 50% RHA treatments. The RHA can be used as a local and low cost substrate component; and the incorporation of 30% (by vol.) RHA in container substrates is a certain amount for lettuce plant growth.

Phytotoxic Evaluation of Phytosynthesized Silver Nanoparticles on Lettuce

The increasing metal release into the environment warrants investigating their impact on plants, which are cornerstones of ecosystems. Here, Lactuca sativa L. (lettuce) seedlings were exposed hydroponically to different concentrations of silver ions and nanoparticles (Ag NPs) for 25 days to evaluate their impact on plant growth. Seedlings taking Ag+ ions showed an increment of 18% in total phenolic content and 12% in total flavonoid content, whereas under Ag NPs, 7% free radical scavenging activity, 12% total phenolic contents (TPC), and 10% total reducing power are increased. An increase in 31% shoot length, 25% chlorophyll, 11% carbohydrate, and 16% protein content of the lettuce plant is observed in response to Ag NPs, while silver nitrate (AgNO3) has a reduced 40% growth. The lettuce plant was most susceptible to toxic effects of Ag+ ions at a lower concentration, i.e., 0.01 mg/L, while Ag NPs showed less toxicity, only when higher concentrations >100 mg/L were applied. Further, biomolecules other than antioxidant enzymes showed higher phytotoxicity for Ag+ ions, followed by Ag NPs with the concentration of 25, 50, and 100 mg/L compared to the control. Thus, moderate concentrations of Ag NPs have a stimulatory effect on seedling growth, while higher concentrations induced inhibitory effects due to the release of Ag+ ions. These results suggest that optimum metallic contents are desirable for the healthier growth of plants in a controlled way.

The Phytoextraction of Copper from Tropical Soil 21 Years after Amendment with Heavy-Metal Containing Waste

Several particular plants are suggested to extract significant parts of heavy metals from soils and accumulate them in their roots and shoots. This research aimed to study the phytoextraction of Cu by several plants from heavy-metal contaminated tropical soils. Soil samples collected from plots treated in 1998 with 0, 15 and 60 Mg industrial waste ha-1 were planted with three different plants, i.e., caisim, water spinach, and lettuce. Plant parts (roots and shoots) and soil samples were harvested after a four-week growth period and analyzed for plant and soil Cu. The results show that the growth of plants was depressed by the increase in the soil Cu (extracted by 1 N HNO3) as affected by waste levels, with water spinach being the most progressive and produced the most significant biomass. The absorption of Cu by caisim and water spinach increased with the soil extracted Cu (linear R2 = 0.71* for caisim and 0.32* for water spinach) and accumulated greater in plant roots than that in shoots. The translocation factor (TF << 1.00) indicates that all plants were good Cu phytostabilizators rather than phytoextractors, with water spinach being the best Cu extractor.

Lettuce growth stage identification based on phytomorphological variations using coupled color superpixels and multifold watershed transformation

Identifying the plant's developmental growth stages from seed leaf is crucial to understand plant science and cultivation management deeply. An efficient vision-based system for plant growth monitoring entails optimum segmentation and classification algorithms. This study presents coupled color-based superpixels and multifold watershed transformation in segmenting lettuce plant from complicated background taken from smart farm aquaponic system, and machine learning models used to classify lettuce plant growth as vegetative, head development and for harvest based on phytomorphological profile. Morphological computations were employed by feature extraction of the number of leaves, biomass area and perimeter, convex area, convex hull area and perimeter, major and minor axis lengths of the major axis length the dominant leaf, and length of plant skeleton. Phytomorphological variations of biomass compactness, convexity, solidity, plant skeleton, and perimeter ratio were included as inputs of the classification network. The extracted Lab color space information from the training image set undergoes superpixels overlaying with 1,000 superpixel regions employing K-means clustering on each pixel class. Six-level watershed transformation with distance transformation and minima imposition was employed to segment the lettuce plant from other pixel objects. The accuracy of correctly classifying the vegetative, head development, and harvest growth stages are 88.89%, 86.67%, and 79.63%, respectively. The experiment shows that the test accuracy rates of machine learning models were recorded as 60% for LDA, 85% for ANN, and 88.33% for QSVM. Comparative analysis showed that QSVM bested the performance of optimized LDA and ANN in classifying lettuce growth stages. This research developed a seamless model in segmenting vegetation pixels, and predicting lettuce growth stage is essential for plant computational phenotyping and agricultural practice optimization.

Induce of Plant Growth Regulators with and without Bio-fertilizer for Enhances the Adverse Effect of Salinity on Germination, Growth and Photosynthetic Pigments

This study aimed to explain the induce of plant growth regulators (ascorbic acid - AsA & salicylic acid - SA) in the presence or absence of bio-fertilizer (Acadian extract –ACE) for alleviated the effect of salinity stress on two cultivars of lettuce (Lactuca sativa, L. cv. Paris & cv. Royal). The lettuce seeds for four cultivars (cv. Paris Island Cos (cv. Paris) S1, cv. Royal S2, cv. Nader S3 & cv. Marvilli S4) soaked in PGRs (AsA, SA & GSH – 0.5 mM) and Acadian extract (ACE - 1%) for 12 hours in the dark at 4°C, for test of lettuce seeds viability (germination rate %). Germination both cultivars (cv. Paris S1 & cv. Royal S2) in trays of cork contains 218 eye for 14 days, transplanted the seedlings plant to plastic containers each pot containing one plant was irrigated with using NaCl salinity concentrations (0.00, 50; 100; 150 mM) 1st group alternative with distilled water and 2nd group alternating with ACE (1%), until harvest after 84 days. The results of germination indicated that the PGRs (AsA & SA) with both cultivars (cv. Paris S1 & cv. Royal S2) gives best results more the other PGRs (GSH) & bio-fertilizer (ACE) for the other cultivars. The data explained that the leaf number and leaf area, fresh and dry weights for shoot decreased significantly with increasing salinity concentrations compared with control, whereas the growth increased significantly more in cv. Royal S2 than in cv. Paris S1, particularly with AsA in the absence of bio-fertilizer (-ACE) more than SA compared with control. Whilst, the shoot succulence increased significantly with salinity concentrations more with AsA than SA especially in the absence of bio-fertilizer (-ACE) compared with control. However, the shoot dry matter content % decreased for both cultivars with increasing NaCl salinity concentrations especially with AsA more than SA in the absence (-ACE) compared with control. The evident recorded a significantly increased the photosynthetic pigments (Chl. a, Chl. b, carotenoids and total pigments) of leaves lettuce plant for both cultivars (cv. Paris & cv. Royal) with increasing NaCl salinity, also the photosynthetic pigments increasing more in cv. Royal S2 than in cv. Paris S1 especially with AsA more than SA in the absence (-ACE) under saline or non-saline conditions compared with the control. The data provide strong support to the hypothesis that exogenous application of AsA individually reduces the harmful effects of salinity and increases resistance to salinity in lettuce plant for both cultivars.

PENGARUH PENAMBAHAN KALIUM NITRAT DALAM LARUTAN HARA PADA MEDIA KASCING TERHADAP PERTUMBUHAN SELADA (Lactuca sativa L.)

This research was conducted with the aim to find out the effect of the addition of potassium nitrate in lettuce as a medium and critical level of concentration(electrical conductivity)of nutrient solution. Research is organized in the form of a pot experiment. The experimental design used was Complete RandomizedBlock Design (CRBD)) with three replications. The treatment consists of 12 levels of concentrations or nutrient solution electrical conductivity with the addition of potassium nitrate to lettuce plant. The treatment level of concentrations (conductivity) of nutrient is as follows; L0 = 0.00; L1 = 1.25; L2 = 2.50; L3 = 3.75; L4 = 5.00; L5 = 6.25; L6 = 7.50; L7 = 8.75; L8 = 10.00; L9 = 11.25; L10 = 12.50 and L1 = 13, 75 g 100 L-1 water. Value concentrations of electrical conductivity each nutrient solution concentrations are: L0 = 0.06; L1 = 0.26; L2 = 0.46; L3 = 0.66; L4 = 0.86; L5 = 1.06; L6 = 1.26; L7 = 1,46; L8 = 1.66; L9 = 1,86; L10 = 2.06 and L1 = 2.26. dS m-1. The result of the experiment showed that addition of KNO3 highly significant effect on the increase in fresh weight and dry weight of shoot per plant. Fresh weight and oven-dry weight of shoot per plant was significantly increased in a quadratic with increasing concentrations of KNO3are optimum for growth of plant shoot weight were at 12.23 g in 100/of water on electrical conductivity equivalent to 2.01 dS.m-1. The addition of concentration of KNO3to nutrient solution does not affect on N and other nutrient solution on shoot tissue of lettuce plant but the concentrations of P and K in plant shoot tissue were significantly increased linearly with the provision of KNO3.