scholarly journals Experiences with Wastes and Composts in Nursery Substrates

2005 ◽  
Vol 15 (4) ◽  
pp. 739-747 ◽  
Author(s):  
Calvin Chong

During the past 20 years, the Ornamental Nursery Research Program at the former Horticultural Research Institute of Ontario (now part of the University of Guelph) has been conducting applied research dealing with environmentally friendly and sustainable nursery production practices with emphasis on container production. The use of farm, industrial, and consumer waste by-products as amendments in nursery substrates has been a major focus. The program has evaluated hundreds of potting mixes derived from individual or combined, raw or composted waste by-products including spent mushroom compost, turkey litter compost, paper mill sludge, municipal waste compost, corrugated cardboard, apple pomace, wood chips from pallets, pulverized glass, and various types of tree barks. With few exceptions, all the above waste by-products tested under our cultural conditions provided acceptable to excellent container-growing media, often in amounts exceeding 50% and sometimes up to 100% by volume in No. 2 containers (6 L), even despite initially elevated and potentially toxic contents of soluble salts [expressed in terms of electrical conductivity measured up to 8.9 dS·m-1 in 1 substrate: 2 water (by volume) extracts] in many of the substrates. A key to these successful results is that salts leach quickly from the containers to benign levels (∼1.0 dS·m-1) with normal irrigation practices. High initial pH in most waste-derived substrates (up to 8.9) has had little or no discernible effect on growth of a wide assortment of deciduous nursery species. By-products such as paper mill sludge and municipal waste compost with soluble salts contents typically ranging from 0.8 to 2.0 dS·m-1, also provide acceptable rooting media provided salts are leached before use to values ≤0.2 dS·m-1. The porosity and aeration characteristics of waste-derived substrates tend to be comparable to, or better than, those of bark.

1999 ◽  
Vol 79 (1) ◽  
pp. 139-148 ◽  
Author(s):  
Calvin Chong

The nursery/landscape industry has been one of the fastest growing agricultural sectors in Canada. Since 1980s, the Ornamental Nursery Research Program at the Horticultural Research Institute of Ontario (HRIO) has been conducting research which focuses on environmentally friendly production practices. Emphasis is on the use of composted or uncomposted organic wastes as amendments in container potting mixes. Various projects have evaluated mixes derived from wastes such as spent mushroom compost, paper mill sludge, apple pomace, and various types of barks. In the late 1980s and early 1990s, the scope of the research expanded to include composting and a wider assortment of wastes such as waxed corrugated cardboard, municipal solid waste compost, wood chips from pallets and furniture and demolition wastes, food wastes, and organic fertilizers manufactured from meat by-products, and selected industrial wastes. Presently, paper mill sludge is being evaluated as field soil amendment for growing nursery shade trees and also for use in rehabilitating marginal, non-agricultural land. Key words: Waste recycling, land rehabilitation, composts, organic wastes, container culture, shade tree culture, ornamentals, nutrition


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1048D-1048
Author(s):  
Calvin Chong ◽  
Peter Purvis

Plug-rooted liners of deutzia (Deutzia gracilis), dogwood (Cornus alba `Argenteo-marginata'), forsythia (Forsythia×intermedia `Lynwood Gold'), and ninebark (Physocarpus opulifolius) were grown in 6-L containers. There were 36 different treatment substrates formulated in factorial combinations: two types of paper mill sludge (raw or composted) each at three rates (25%, 33%, or 50%, by volume) mixed with one of three sources of municipal waste compost (cities of Guelph, Toronto, or Waterloo; 25%, 33%, or 50%), and the remainder consisting of one of two base supplements (pine bark or 1-year-old wood chips; 50%, 33%, or 0%). The containers were trickle-irrigated and fertilized with a controlled-release fertilizer. Dogwood (no treatment interaction and responding only to the main effect of compost sources) grew equally well with Toronto and Waterloo composts, but less well with the Guelph compost. Ninebark tended to grow better with Toronto compost, intermediate or similar with Waterloo compost, and least with Guelph compost. Forsythia grew equally well in all bark-based substrates, regardless of sludge type and rate or compost source. With wood-chip-based substrates, however, forsythia grew better with Waterloo than with Guelph compost, and better with raw than with composted sludge when mixed with Toronto compost. Deutzia responded similarly to most substrates, but grew marginally better with raw than with composted paper sludge when Waterloo or Toronto compost was present. Despite these differences in species responses, all plants were of marketable size at the end of the season. There was no sign of nutrient toxicity or deficiency due to any of the substrates.


2018 ◽  
Vol 78 (8) ◽  
pp. 1753-1761
Author(s):  
Pingfeng Fu ◽  
Zihao Chen ◽  
Tianwen Yang

Abstract The porous metallic iron/carbon (Fe0/C) ceramsites, with virtues of low cost and ‘green’ fabrication, were prepared by direct reduction roasting of magnetite, coal, and paper mill sludge. The X-ray diffraction data revealed that Fe0 was generated in situ by reducing the magnetite at 1,200 °C. Scanning electron microscopy with energy-dispersive X-ray spectroscopy indicated that Fe0 particles, with a size of <10 μm, were highly dispersed on carbon particles to form an integrated anode (Fe0) and cathode (C) structure of microelectrolysis filters. The effects of initial solution pH and Fe/C mass ratio on Cu2+ removal were investigated. The extent of Cu2+ removal increased from 93.53% to 99.81% as initial pH rose from 2.5 to 7.0. The residual Cu2+ concentration was as low as <0.2 mg/L. The highest extent of Cu2+ removal was achieved at Fe/C mass ratio of 6.8:1. The pseudo-second-order kinetic model fitted well for Cu2+ removal by the ceramsite, revealing the chemisorption as a limiting step. The Cu2+ adsorption equilibrium data were well described by the Langmuir isotherm, with a maximum adsorption capacity of 546.45 mg/g at initial pH 3.0.


HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 818A-818 ◽  
Author(s):  
Calvin Chong* ◽  
Peter Purvis

Silverleaf dogwood (Cornus alba L. `Argenteo-marginata'), forsythia (Forsythia × intermedia Zab. `Lynwood Gold'), and weigela (Weigela florida Bunge A.DC. `Red Prince') were grown in #2 (6-L) containers filled with 100% bark or bark mixed with 20%, 40%, or 60% (by vol.) each of raw paper mill sludge (RB group), composted paper mill sludge (CB group), a proprietory paper mill sludge-derived compost (PB group), and municipal compost (MB group). A fifth substrate group (MH) consisted of 100% hemp chips or hemp chips mixed with the same rates of municipal compost. The containers were trickle-irrigated and fertilized with a controlled-release fertilizer. Among the bark-amended groups, growth was highest for dogwood and forsythia with PB, increasing dramatically and peaking at ca. 40% rate (68 and 94 g/plant top dry weight, respectively). Growth of these species was intermediate with MB and CB and least with RB, increasing to rates ≥ 50% in these groups, except for a nonsignificant response of dogwood to RB. Growth of weigela increased equally with PB and MB substrates up to ca. 40% (117 g/plant), but was unresponsive to rates of RB and CB. With the hemp-amended MH group, growth of all three species increased to rates ≥ 50% (62, 93, and 116 g/plant for dogwood, forsythia, and weigela, respectively). Growth of the three species over most rates of all substrate groups was similar to, or exceeded, that in 80% bark: 15% peat: 5% topsoil, a proven nursery mix. Top dry weight of all three species was positively correlated with soluble salts concentrations in the substrates at planting after first irrigation (0.23-1.72 dS·m-1, range over all substrates) and at various intervals during the season.


2004 ◽  
Vol 84 (4) ◽  
pp. 1127-1134 ◽  
Author(s):  
Calvin Chong ◽  
Peter Purvis

Silverleaf dogwood (Cornus alba L. ‘Argenteo-marginata’), forsythia (Forsythia × intermedia Zab. ‘Lynwood Gold’), and weigela (Weigela florida Bunge A.DC. ‘Red Prince’) were grown in #2 (6-L) containers filled with 100% bark or bark mixed with 20, 40 or 60% by volume each of raw paper mill sludge (RB group), Bio Soil compost containing 100% paper mill sludge (BCB group), Waterdown compost containing 40% paper sludge, 40% chicken manure and 20% sawdust (WCB group), and municipal compost consisting of leaf and yard waste (MCB group). A fifth substrate group (MCH) consisted of 100% hemp chips or hemp chips mixed with the same rates of municipal compost. The containers were trickle-irrigated and fertilized with a controlled-release fertilizer. Regression analysis indicated that growth among the barkamended groups was highest for dogwood and forsythia with WCB, increasing dramatically and peaking at about the 40% rate (68 and 94 g plant-1 aboveground dry weight, respectively). Growth of these species was intermediate with MCB and BCB and least with RB, increasing to rates ≥ 50% in these groups. There was no significant response of dogwood to RB. Growth of weigela increased equally with WCB and MCB substrates up to about 40% (117 g plant-1), but was not influenced by varying rates of RB and BCB. With the hemp-amended MCH group, growth of all three species increased to rates ≥ 50% (62, 93, and 116 g plant-1 for dogwood, forsythia and weigela, respectively). Growth of the three species over most rates of all substrate groups was similar to, or exceeded that in 80% bark: 15% peat: 5% topsoil, a proven nursery mix. Aboveground dry weight of all three species was positively correlated with soluble salts concentrations in the substrates sampled at planting and on other sampling dates during the season. Key words: Nursery, ornamentals, waste and compost utilization


Author(s):  
Zhiyong Xu ◽  
Yunqin Lin ◽  
Yuejin Lin ◽  
De Yang ◽  
Haomin Zheng

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2031
Author(s):  
Ruben Miranda ◽  
Isabel Latour ◽  
Angeles Blanco

Effluent reuse is a common practice for sustainable industrial water use. Salt removal is usually carried out by a combination of membrane processes with a final reverse osmosis (RO). However, the presence of silica limits the RO efficiency due to its high scaling potential and the difficulty of cleaning the fouled membranes. Silica adsorption has many advantages compared to coagulation and precipitation at high pHs: pH adjustment is not necessary, the conductivity of treated waters is not increased, and there is no sludge generation. Therefore, this study investigates the feasibility of using pseudoboehmite and its calcination product (γ-Al2O3) for silica adsorption from a paper mill effluent. The effect of sorbent dosage, pH, and temperature, including both equilibrium and kinetics studies, were studied. γ-Al2O3 was clearly more efficient than pseudoboehmite, with optimal dosages around 2.5–5 g/L vs. 7.5–15 g/L. The optimum pH is around 8.5–10, which fits well with the initial pH of the effluent. The kinetics of silica adsorption is fast, especially at high dosages and temperatures: 80–90% of the removable silica is removed in 1 h. At these conditions, silica removal is around 75–85% (<50 mg/L SiO2 in the treated water).


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